1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
  24  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
  25  */
  26 
  27 /* Portions Copyright 2007 Jeremy Teo */
  28 /* Portions Copyright 2010 Robert Milkowski */
  29 
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/time.h>
  33 #include <sys/systm.h>
  34 #include <sys/sysmacros.h>
  35 #include <sys/resource.h>
  36 #include <sys/vfs.h>
  37 #include <sys/vfs_opreg.h>
  38 #include <sys/vnode.h>
  39 #include <sys/file.h>
  40 #include <sys/stat.h>
  41 #include <sys/kmem.h>
  42 #include <sys/taskq.h>
  43 #include <sys/uio.h>
  44 #include <sys/vmsystm.h>
  45 #include <sys/atomic.h>
  46 #include <sys/vm.h>
  47 #include <vm/seg_vn.h>
  48 #include <vm/pvn.h>
  49 #include <vm/as.h>
  50 #include <vm/kpm.h>
  51 #include <vm/seg_kpm.h>
  52 #include <sys/mman.h>
  53 #include <sys/pathname.h>
  54 #include <sys/cmn_err.h>
  55 #include <sys/errno.h>
  56 #include <sys/unistd.h>
  57 #include <sys/zfs_dir.h>
  58 #include <sys/zfs_acl.h>
  59 #include <sys/zfs_ioctl.h>
  60 #include <sys/fs/zfs.h>
  61 #include <sys/dmu.h>
  62 #include <sys/dmu_objset.h>
  63 #include <sys/spa.h>
  64 #include <sys/txg.h>
  65 #include <sys/dbuf.h>
  66 #include <sys/zap.h>
  67 #include <sys/sa.h>
  68 #include <sys/dirent.h>
  69 #include <sys/policy.h>
  70 #include <sys/sunddi.h>
  71 #include <sys/filio.h>
  72 #include <sys/sid.h>
  73 #include "fs/fs_subr.h"
  74 #include <sys/zfs_ctldir.h>
  75 #include <sys/zfs_fuid.h>
  76 #include <sys/zfs_sa.h>
  77 #include <sys/dnlc.h>
  78 #include <sys/zfs_rlock.h>
  79 #include <sys/extdirent.h>
  80 #include <sys/kidmap.h>
  81 #include <sys/cred.h>
  82 #include <sys/attr.h>
  83 
  84 /*
  85  * Programming rules.
  86  *
  87  * Each vnode op performs some logical unit of work.  To do this, the ZPL must
  88  * properly lock its in-core state, create a DMU transaction, do the work,
  89  * record this work in the intent log (ZIL), commit the DMU transaction,
  90  * and wait for the intent log to commit if it is a synchronous operation.
  91  * Moreover, the vnode ops must work in both normal and log replay context.
  92  * The ordering of events is important to avoid deadlocks and references
  93  * to freed memory.  The example below illustrates the following Big Rules:
  94  *
  95  *  (1) A check must be made in each zfs thread for a mounted file system.
  96  *      This is done avoiding races using ZFS_ENTER(zfsvfs).
  97  *      A ZFS_EXIT(zfsvfs) is needed before all returns.  Any znodes
  98  *      must be checked with ZFS_VERIFY_ZP(zp).  Both of these macros
  99  *      can return EIO from the calling function.
 100  *
 101  *  (2) VN_RELE() should always be the last thing except for zil_commit()
 102  *      (if necessary) and ZFS_EXIT(). This is for 3 reasons:
 103  *      First, if it's the last reference, the vnode/znode
 104  *      can be freed, so the zp may point to freed memory.  Second, the last
 105  *      reference will call zfs_zinactive(), which may induce a lot of work --
 106  *      pushing cached pages (which acquires range locks) and syncing out
 107  *      cached atime changes.  Third, zfs_zinactive() may require a new tx,
 108  *      which could deadlock the system if you were already holding one.
 109  *      If you must call VN_RELE() within a tx then use VN_RELE_ASYNC().
 110  *
 111  *  (3) All range locks must be grabbed before calling dmu_tx_assign(),
 112  *      as they can span dmu_tx_assign() calls.
 113  *
 114  *  (4) If ZPL locks are held, pass TXG_NOWAIT as the second argument to
 115  *      dmu_tx_assign().  This is critical because we don't want to block
 116  *      while holding locks.
 117  *
 118  *      If no ZPL locks are held (aside from ZFS_ENTER()), use TXG_WAIT.  This
 119  *      reduces lock contention and CPU usage when we must wait (note that if
 120  *      throughput is constrained by the storage, nearly every transaction
 121  *      must wait).
 122  *
 123  *      Note, in particular, that if a lock is sometimes acquired before
 124  *      the tx assigns, and sometimes after (e.g. z_lock), then failing
 125  *      to use a non-blocking assign can deadlock the system.  The scenario:
 126  *
 127  *      Thread A has grabbed a lock before calling dmu_tx_assign().
 128  *      Thread B is in an already-assigned tx, and blocks for this lock.
 129  *      Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open()
 130  *      forever, because the previous txg can't quiesce until B's tx commits.
 131  *
 132  *      If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT,
 133  *      then drop all locks, call dmu_tx_wait(), and try again.  On subsequent
 134  *      calls to dmu_tx_assign(), pass TXG_WAITED rather than TXG_NOWAIT,
 135  *      to indicate that this operation has already called dmu_tx_wait().
 136  *      This will ensure that we don't retry forever, waiting a short bit
 137  *      each time.
 138  *
 139  *  (5) If the operation succeeded, generate the intent log entry for it
 140  *      before dropping locks.  This ensures that the ordering of events
 141  *      in the intent log matches the order in which they actually occurred.
 142  *      During ZIL replay the zfs_log_* functions will update the sequence
 143  *      number to indicate the zil transaction has replayed.
 144  *
 145  *  (6) At the end of each vnode op, the DMU tx must always commit,
 146  *      regardless of whether there were any errors.
 147  *
 148  *  (7) After dropping all locks, invoke zil_commit(zilog, foid)
 149  *      to ensure that synchronous semantics are provided when necessary.
 150  *
 151  * In general, this is how things should be ordered in each vnode op:
 152  *
 153  *      ZFS_ENTER(zfsvfs);              // exit if unmounted
 154  * top:
 155  *      zfs_dirent_lock(&dl, ...)   // lock directory entry (may VN_HOLD())
 156  *      rw_enter(...);                  // grab any other locks you need
 157  *      tx = dmu_tx_create(...);        // get DMU tx
 158  *      dmu_tx_hold_*();                // hold each object you might modify
 159  *      error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
 160  *      if (error) {
 161  *              rw_exit(...);           // drop locks
 162  *              zfs_dirent_unlock(dl);  // unlock directory entry
 163  *              VN_RELE(...);           // release held vnodes
 164  *              if (error == ERESTART) {
 165  *                      waited = B_TRUE;
 166  *                      dmu_tx_wait(tx);
 167  *                      dmu_tx_abort(tx);
 168  *                      goto top;
 169  *              }
 170  *              dmu_tx_abort(tx);       // abort DMU tx
 171  *              ZFS_EXIT(zfsvfs);       // finished in zfs
 172  *              return (error);         // really out of space
 173  *      }
 174  *      error = do_real_work();         // do whatever this VOP does
 175  *      if (error == 0)
 176  *              zfs_log_*(...);         // on success, make ZIL entry
 177  *      dmu_tx_commit(tx);              // commit DMU tx -- error or not
 178  *      rw_exit(...);                   // drop locks
 179  *      zfs_dirent_unlock(dl);          // unlock directory entry
 180  *      VN_RELE(...);                   // release held vnodes
 181  *      zil_commit(zilog, foid);        // synchronous when necessary
 182  *      ZFS_EXIT(zfsvfs);               // finished in zfs
 183  *      return (error);                 // done, report error
 184  */
 185 
 186 /* ARGSUSED */
 187 static int
 188 zfs_open(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
 189 {
 190         znode_t *zp = VTOZ(*vpp);
 191         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 192 
 193         ZFS_ENTER(zfsvfs);
 194         ZFS_VERIFY_ZP(zp);
 195 
 196         if ((flag & FWRITE) && (zp->z_pflags & ZFS_APPENDONLY) &&
 197             ((flag & FAPPEND) == 0)) {
 198                 ZFS_EXIT(zfsvfs);
 199                 return (SET_ERROR(EPERM));
 200         }
 201 
 202         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 203             ZTOV(zp)->v_type == VREG &&
 204             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0) {
 205                 if (fs_vscan(*vpp, cr, 0) != 0) {
 206                         ZFS_EXIT(zfsvfs);
 207                         return (SET_ERROR(EACCES));
 208                 }
 209         }
 210 
 211         /* Keep a count of the synchronous opens in the znode */
 212         if (flag & (FSYNC | FDSYNC))
 213                 atomic_inc_32(&zp->z_sync_cnt);
 214 
 215         ZFS_EXIT(zfsvfs);
 216         return (0);
 217 }
 218 
 219 /* ARGSUSED */
 220 static int
 221 zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr,
 222     caller_context_t *ct)
 223 {
 224         znode_t *zp = VTOZ(vp);
 225         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 226 
 227         /*
 228          * Clean up any locks held by this process on the vp.
 229          */
 230         cleanlocks(vp, ddi_get_pid(), 0);
 231         cleanshares(vp, ddi_get_pid());
 232 
 233         ZFS_ENTER(zfsvfs);
 234         ZFS_VERIFY_ZP(zp);
 235 
 236         /* Decrement the synchronous opens in the znode */
 237         if ((flag & (FSYNC | FDSYNC)) && (count == 1))
 238                 atomic_dec_32(&zp->z_sync_cnt);
 239 
 240         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 241             ZTOV(zp)->v_type == VREG &&
 242             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0)
 243                 VERIFY(fs_vscan(vp, cr, 1) == 0);
 244 
 245         ZFS_EXIT(zfsvfs);
 246         return (0);
 247 }
 248 
 249 /*
 250  * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and
 251  * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter.
 252  */
 253 static int
 254 zfs_holey(vnode_t *vp, int cmd, offset_t *off)
 255 {
 256         znode_t *zp = VTOZ(vp);
 257         uint64_t noff = (uint64_t)*off; /* new offset */
 258         uint64_t file_sz;
 259         int error;
 260         boolean_t hole;
 261 
 262         file_sz = zp->z_size;
 263         if (noff >= file_sz)  {
 264                 return (SET_ERROR(ENXIO));
 265         }
 266 
 267         if (cmd == _FIO_SEEK_HOLE)
 268                 hole = B_TRUE;
 269         else
 270                 hole = B_FALSE;
 271 
 272         error = dmu_offset_next(zp->z_zfsvfs->z_os, zp->z_id, hole, &noff);
 273 
 274         if (error == ESRCH)
 275                 return (SET_ERROR(ENXIO));
 276 
 277         /*
 278          * We could find a hole that begins after the logical end-of-file,
 279          * because dmu_offset_next() only works on whole blocks.  If the
 280          * EOF falls mid-block, then indicate that the "virtual hole"
 281          * at the end of the file begins at the logical EOF, rather than
 282          * at the end of the last block.
 283          */
 284         if (noff > file_sz) {
 285                 ASSERT(hole);
 286                 noff = file_sz;
 287         }
 288 
 289         if (noff < *off)
 290                 return (error);
 291         *off = noff;
 292         return (error);
 293 }
 294 
 295 /* ARGSUSED */
 296 static int
 297 zfs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
 298     int *rvalp, caller_context_t *ct)
 299 {
 300         offset_t off;
 301         offset_t ndata;
 302         dmu_object_info_t doi;
 303         int error;
 304         zfsvfs_t *zfsvfs;
 305         znode_t *zp;
 306 
 307         switch (com) {
 308         case _FIOFFS:
 309         {
 310                 return (zfs_sync(vp->v_vfsp, 0, cred));
 311 
 312                 /*
 313                  * The following two ioctls are used by bfu.  Faking out,
 314                  * necessary to avoid bfu errors.
 315                  */
 316         }
 317         case _FIOGDIO:
 318         case _FIOSDIO:
 319         {
 320                 return (0);
 321         }
 322 
 323         case _FIO_SEEK_DATA:
 324         case _FIO_SEEK_HOLE:
 325         {
 326                 if (ddi_copyin((void *)data, &off, sizeof (off), flag))
 327                         return (SET_ERROR(EFAULT));
 328 
 329                 zp = VTOZ(vp);
 330                 zfsvfs = zp->z_zfsvfs;
 331                 ZFS_ENTER(zfsvfs);
 332                 ZFS_VERIFY_ZP(zp);
 333 
 334                 /* offset parameter is in/out */
 335                 error = zfs_holey(vp, com, &off);
 336                 ZFS_EXIT(zfsvfs);
 337                 if (error)
 338                         return (error);
 339                 if (ddi_copyout(&off, (void *)data, sizeof (off), flag))
 340                         return (SET_ERROR(EFAULT));
 341                 return (0);
 342         }
 343         case _FIO_COUNT_FILLED:
 344         {
 345                 /*
 346                  * _FIO_COUNT_FILLED adds a new ioctl command which
 347                  * exposes the number of filled blocks in a
 348                  * ZFS object.
 349                  */
 350                 zp = VTOZ(vp);
 351                 zfsvfs = zp->z_zfsvfs;
 352                 ZFS_ENTER(zfsvfs);
 353                 ZFS_VERIFY_ZP(zp);
 354 
 355                 /*
 356                  * Wait for all dirty blocks for this object
 357                  * to get synced out to disk, and the DMU info
 358                  * updated.
 359                  */
 360                 error = dmu_object_wait_synced(zfsvfs->z_os, zp->z_id);
 361                 if (error) {
 362                         ZFS_EXIT(zfsvfs);
 363                         return (error);
 364                 }
 365 
 366                 /*
 367                  * Retrieve fill count from DMU object.
 368                  */
 369                 error = dmu_object_info(zfsvfs->z_os, zp->z_id, &doi);
 370                 if (error) {
 371                         ZFS_EXIT(zfsvfs);
 372                         return (error);
 373                 }
 374 
 375                 ndata = doi.doi_fill_count;
 376 
 377                 ZFS_EXIT(zfsvfs);
 378                 if (ddi_copyout(&ndata, (void *)data, sizeof (ndata), flag))
 379                         return (SET_ERROR(EFAULT));
 380                 return (0);
 381         }
 382         }
 383         return (SET_ERROR(ENOTTY));
 384 }
 385 
 386 /*
 387  * Utility functions to map and unmap a single physical page.  These
 388  * are used to manage the mappable copies of ZFS file data, and therefore
 389  * do not update ref/mod bits.
 390  */
 391 caddr_t
 392 zfs_map_page(page_t *pp, enum seg_rw rw)
 393 {
 394         if (kpm_enable)
 395                 return (hat_kpm_mapin(pp, 0));
 396         ASSERT(rw == S_READ || rw == S_WRITE);
 397         return (ppmapin(pp, PROT_READ | ((rw == S_WRITE) ? PROT_WRITE : 0),
 398             (caddr_t)-1));
 399 }
 400 
 401 void
 402 zfs_unmap_page(page_t *pp, caddr_t addr)
 403 {
 404         if (kpm_enable) {
 405                 hat_kpm_mapout(pp, 0, addr);
 406         } else {
 407                 ppmapout(addr);
 408         }
 409 }
 410 
 411 /*
 412  * When a file is memory mapped, we must keep the IO data synchronized
 413  * between the DMU cache and the memory mapped pages.  What this means:
 414  *
 415  * On Write:    If we find a memory mapped page, we write to *both*
 416  *              the page and the dmu buffer.
 417  */
 418 static void
 419 update_pages(vnode_t *vp, int64_t start, int len, objset_t *os, uint64_t oid)
 420 {
 421         int64_t off;
 422 
 423         off = start & PAGEOFFSET;
 424         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 425                 page_t *pp;
 426                 uint64_t nbytes = MIN(PAGESIZE - off, len);
 427 
 428                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 429                         caddr_t va;
 430 
 431                         va = zfs_map_page(pp, S_WRITE);
 432                         (void) dmu_read(os, oid, start+off, nbytes, va+off,
 433                             DMU_READ_PREFETCH);
 434                         zfs_unmap_page(pp, va);
 435                         page_unlock(pp);
 436                 }
 437                 len -= nbytes;
 438                 off = 0;
 439         }
 440 }
 441 
 442 /*
 443  * When a file is memory mapped, we must keep the IO data synchronized
 444  * between the DMU cache and the memory mapped pages.  What this means:
 445  *
 446  * On Read:     We "read" preferentially from memory mapped pages,
 447  *              else we default from the dmu buffer.
 448  *
 449  * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
 450  *       the file is memory mapped.
 451  */
 452 static int
 453 mappedread(vnode_t *vp, int nbytes, uio_t *uio)
 454 {
 455         znode_t *zp = VTOZ(vp);
 456         int64_t start, off;
 457         int len = nbytes;
 458         int error = 0;
 459 
 460         start = uio->uio_loffset;
 461         off = start & PAGEOFFSET;
 462         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 463                 page_t *pp;
 464                 uint64_t bytes = MIN(PAGESIZE - off, len);
 465 
 466                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 467                         caddr_t va;
 468 
 469                         va = zfs_map_page(pp, S_READ);
 470                         error = uiomove(va + off, bytes, UIO_READ, uio);
 471                         zfs_unmap_page(pp, va);
 472                         page_unlock(pp);
 473                 } else {
 474                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 475                             uio, bytes);
 476                 }
 477                 len -= bytes;
 478                 off = 0;
 479                 if (error)
 480                         break;
 481         }
 482         return (error);
 483 }
 484 
 485 offset_t zfs_read_chunk_size = 1024 * 1024; /* Tunable */
 486 
 487 /*
 488  * Read bytes from specified file into supplied buffer.
 489  *
 490  *      IN:     vp      - vnode of file to be read from.
 491  *              uio     - structure supplying read location, range info,
 492  *                        and return buffer.
 493  *              ioflag  - SYNC flags; used to provide FRSYNC semantics.
 494  *              cr      - credentials of caller.
 495  *              ct      - caller context
 496  *
 497  *      OUT:    uio     - updated offset and range, buffer filled.
 498  *
 499  *      RETURN: 0 on success, error code on failure.
 500  *
 501  * Side Effects:
 502  *      vp - atime updated if byte count > 0
 503  */
 504 /* ARGSUSED */
 505 static int
 506 zfs_read(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 507 {
 508         znode_t         *zp = VTOZ(vp);
 509         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 510         ssize_t         n, nbytes;
 511         int             error = 0;
 512         rl_t            *rl;
 513         xuio_t          *xuio = NULL;
 514 
 515         ZFS_ENTER(zfsvfs);
 516         ZFS_VERIFY_ZP(zp);
 517 
 518         if (zp->z_pflags & ZFS_AV_QUARANTINED) {
 519                 ZFS_EXIT(zfsvfs);
 520                 return (SET_ERROR(EACCES));
 521         }
 522 
 523         /*
 524          * Validate file offset
 525          */
 526         if (uio->uio_loffset < (offset_t)0) {
 527                 ZFS_EXIT(zfsvfs);
 528                 return (SET_ERROR(EINVAL));
 529         }
 530 
 531         /*
 532          * Fasttrack empty reads
 533          */
 534         if (uio->uio_resid == 0) {
 535                 ZFS_EXIT(zfsvfs);
 536                 return (0);
 537         }
 538 
 539         /*
 540          * Check for mandatory locks
 541          */
 542         if (MANDMODE(zp->z_mode)) {
 543                 if (error = chklock(vp, FREAD,
 544                     uio->uio_loffset, uio->uio_resid, uio->uio_fmode, ct)) {
 545                         ZFS_EXIT(zfsvfs);
 546                         return (error);
 547                 }
 548         }
 549 
 550         /*
 551          * If we're in FRSYNC mode, sync out this znode before reading it.
 552          */
 553         if (ioflag & FRSYNC || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
 554                 zil_commit(zfsvfs->z_log, zp->z_id);
 555 
 556         /*
 557          * Lock the range against changes.
 558          */
 559         rl = zfs_range_lock(zp, uio->uio_loffset, uio->uio_resid, RL_READER);
 560 
 561         /*
 562          * If we are reading past end-of-file we can skip
 563          * to the end; but we might still need to set atime.
 564          */
 565         if (uio->uio_loffset >= zp->z_size) {
 566                 error = 0;
 567                 goto out;
 568         }
 569 
 570         ASSERT(uio->uio_loffset < zp->z_size);
 571         n = MIN(uio->uio_resid, zp->z_size - uio->uio_loffset);
 572 
 573         if ((uio->uio_extflg == UIO_XUIO) &&
 574             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY)) {
 575                 int nblk;
 576                 int blksz = zp->z_blksz;
 577                 uint64_t offset = uio->uio_loffset;
 578 
 579                 xuio = (xuio_t *)uio;
 580                 if ((ISP2(blksz))) {
 581                         nblk = (P2ROUNDUP(offset + n, blksz) - P2ALIGN(offset,
 582                             blksz)) / blksz;
 583                 } else {
 584                         ASSERT(offset + n <= blksz);
 585                         nblk = 1;
 586                 }
 587                 (void) dmu_xuio_init(xuio, nblk);
 588 
 589                 if (vn_has_cached_data(vp)) {
 590                         /*
 591                          * For simplicity, we always allocate a full buffer
 592                          * even if we only expect to read a portion of a block.
 593                          */
 594                         while (--nblk >= 0) {
 595                                 (void) dmu_xuio_add(xuio,
 596                                     dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
 597                                     blksz), 0, blksz);
 598                         }
 599                 }
 600         }
 601 
 602         while (n > 0) {
 603                 nbytes = MIN(n, zfs_read_chunk_size -
 604                     P2PHASE(uio->uio_loffset, zfs_read_chunk_size));
 605 
 606                 if (vn_has_cached_data(vp)) {
 607                         error = mappedread(vp, nbytes, uio);
 608                 } else {
 609                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 610                             uio, nbytes);
 611                 }
 612                 if (error) {
 613                         /* convert checksum errors into IO errors */
 614                         if (error == ECKSUM)
 615                                 error = SET_ERROR(EIO);
 616                         break;
 617                 }
 618 
 619                 n -= nbytes;
 620         }
 621 out:
 622         zfs_range_unlock(rl);
 623 
 624         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
 625         ZFS_EXIT(zfsvfs);
 626         return (error);
 627 }
 628 
 629 /*
 630  * Write the bytes to a file.
 631  *
 632  *      IN:     vp      - vnode of file to be written to.
 633  *              uio     - structure supplying write location, range info,
 634  *                        and data buffer.
 635  *              ioflag  - FAPPEND, FSYNC, and/or FDSYNC.  FAPPEND is
 636  *                        set if in append mode.
 637  *              cr      - credentials of caller.
 638  *              ct      - caller context (NFS/CIFS fem monitor only)
 639  *
 640  *      OUT:    uio     - updated offset and range.
 641  *
 642  *      RETURN: 0 on success, error code on failure.
 643  *
 644  * Timestamps:
 645  *      vp - ctime|mtime updated if byte count > 0
 646  */
 647 
 648 /* ARGSUSED */
 649 static int
 650 zfs_write(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 651 {
 652         znode_t         *zp = VTOZ(vp);
 653         rlim64_t        limit = uio->uio_llimit;
 654         ssize_t         start_resid = uio->uio_resid;
 655         ssize_t         tx_bytes;
 656         uint64_t        end_size;
 657         dmu_tx_t        *tx;
 658         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 659         zilog_t         *zilog;
 660         offset_t        woff;
 661         ssize_t         n, nbytes;
 662         rl_t            *rl;
 663         int             max_blksz = zfsvfs->z_max_blksz;
 664         int             error = 0;
 665         arc_buf_t       *abuf;
 666         iovec_t         *aiov = NULL;
 667         xuio_t          *xuio = NULL;
 668         int             i_iov = 0;
 669         int             iovcnt = uio->uio_iovcnt;
 670         iovec_t         *iovp = uio->uio_iov;
 671         int             write_eof;
 672         int             count = 0;
 673         sa_bulk_attr_t  bulk[4];
 674         uint64_t        mtime[2], ctime[2];
 675 
 676         /*
 677          * Fasttrack empty write
 678          */
 679         n = start_resid;
 680         if (n == 0)
 681                 return (0);
 682 
 683         if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T)
 684                 limit = MAXOFFSET_T;
 685 
 686         ZFS_ENTER(zfsvfs);
 687         ZFS_VERIFY_ZP(zp);
 688 
 689         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
 690         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
 691         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
 692             &zp->z_size, 8);
 693         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
 694             &zp->z_pflags, 8);
 695 
 696         /*
 697          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
 698          * callers might not be able to detect properly that we are read-only,
 699          * so check it explicitly here.
 700          */
 701         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
 702                 ZFS_EXIT(zfsvfs);
 703                 return (SET_ERROR(EROFS));
 704         }
 705 
 706         /*
 707          * If immutable or not appending then return EPERM
 708          */
 709         if ((zp->z_pflags & (ZFS_IMMUTABLE | ZFS_READONLY)) ||
 710             ((zp->z_pflags & ZFS_APPENDONLY) && !(ioflag & FAPPEND) &&
 711             (uio->uio_loffset < zp->z_size))) {
 712                 ZFS_EXIT(zfsvfs);
 713                 return (SET_ERROR(EPERM));
 714         }
 715 
 716         zilog = zfsvfs->z_log;
 717 
 718         /*
 719          * Validate file offset
 720          */
 721         woff = ioflag & FAPPEND ? zp->z_size : uio->uio_loffset;
 722         if (woff < 0) {
 723                 ZFS_EXIT(zfsvfs);
 724                 return (SET_ERROR(EINVAL));
 725         }
 726 
 727         /*
 728          * Check for mandatory locks before calling zfs_range_lock()
 729          * in order to prevent a deadlock with locks set via fcntl().
 730          */
 731         if (MANDMODE((mode_t)zp->z_mode) &&
 732             (error = chklock(vp, FWRITE, woff, n, uio->uio_fmode, ct)) != 0) {
 733                 ZFS_EXIT(zfsvfs);
 734                 return (error);
 735         }
 736 
 737         /*
 738          * Pre-fault the pages to ensure slow (eg NFS) pages
 739          * don't hold up txg.
 740          * Skip this if uio contains loaned arc_buf.
 741          */
 742         if ((uio->uio_extflg == UIO_XUIO) &&
 743             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY))
 744                 xuio = (xuio_t *)uio;
 745         else
 746                 uio_prefaultpages(MIN(n, max_blksz), uio);
 747 
 748         /*
 749          * If in append mode, set the io offset pointer to eof.
 750          */
 751         if (ioflag & FAPPEND) {
 752                 /*
 753                  * Obtain an appending range lock to guarantee file append
 754                  * semantics.  We reset the write offset once we have the lock.
 755                  */
 756                 rl = zfs_range_lock(zp, 0, n, RL_APPEND);
 757                 woff = rl->r_off;
 758                 if (rl->r_len == UINT64_MAX) {
 759                         /*
 760                          * We overlocked the file because this write will cause
 761                          * the file block size to increase.
 762                          * Note that zp_size cannot change with this lock held.
 763                          */
 764                         woff = zp->z_size;
 765                 }
 766                 uio->uio_loffset = woff;
 767         } else {
 768                 /*
 769                  * Note that if the file block size will change as a result of
 770                  * this write, then this range lock will lock the entire file
 771                  * so that we can re-write the block safely.
 772                  */
 773                 rl = zfs_range_lock(zp, woff, n, RL_WRITER);
 774         }
 775 
 776         if (woff >= limit) {
 777                 zfs_range_unlock(rl);
 778                 ZFS_EXIT(zfsvfs);
 779                 return (SET_ERROR(EFBIG));
 780         }
 781 
 782         if ((woff + n) > limit || woff > (limit - n))
 783                 n = limit - woff;
 784 
 785         /* Will this write extend the file length? */
 786         write_eof = (woff + n > zp->z_size);
 787 
 788         end_size = MAX(zp->z_size, woff + n);
 789 
 790         /*
 791          * Write the file in reasonable size chunks.  Each chunk is written
 792          * in a separate transaction; this keeps the intent log records small
 793          * and allows us to do more fine-grained space accounting.
 794          */
 795         while (n > 0) {
 796                 abuf = NULL;
 797                 woff = uio->uio_loffset;
 798                 if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
 799                     zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
 800                         if (abuf != NULL)
 801                                 dmu_return_arcbuf(abuf);
 802                         error = SET_ERROR(EDQUOT);
 803                         break;
 804                 }
 805 
 806                 if (xuio && abuf == NULL) {
 807                         ASSERT(i_iov < iovcnt);
 808                         aiov = &iovp[i_iov];
 809                         abuf = dmu_xuio_arcbuf(xuio, i_iov);
 810                         dmu_xuio_clear(xuio, i_iov);
 811                         DTRACE_PROBE3(zfs_cp_write, int, i_iov,
 812                             iovec_t *, aiov, arc_buf_t *, abuf);
 813                         ASSERT((aiov->iov_base == abuf->b_data) ||
 814                             ((char *)aiov->iov_base - (char *)abuf->b_data +
 815                             aiov->iov_len == arc_buf_size(abuf)));
 816                         i_iov++;
 817                 } else if (abuf == NULL && n >= max_blksz &&
 818                     woff >= zp->z_size &&
 819                     P2PHASE(woff, max_blksz) == 0 &&
 820                     zp->z_blksz == max_blksz) {
 821                         /*
 822                          * This write covers a full block.  "Borrow" a buffer
 823                          * from the dmu so that we can fill it before we enter
 824                          * a transaction.  This avoids the possibility of
 825                          * holding up the transaction if the data copy hangs
 826                          * up on a pagefault (e.g., from an NFS server mapping).
 827                          */
 828                         size_t cbytes;
 829 
 830                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
 831                             max_blksz);
 832                         ASSERT(abuf != NULL);
 833                         ASSERT(arc_buf_size(abuf) == max_blksz);
 834                         if (error = uiocopy(abuf->b_data, max_blksz,
 835                             UIO_WRITE, uio, &cbytes)) {
 836                                 dmu_return_arcbuf(abuf);
 837                                 break;
 838                         }
 839                         ASSERT(cbytes == max_blksz);
 840                 }
 841 
 842                 /*
 843                  * Start a transaction.
 844                  */
 845                 tx = dmu_tx_create(zfsvfs->z_os);
 846                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
 847                 dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz));
 848                 zfs_sa_upgrade_txholds(tx, zp);
 849                 error = dmu_tx_assign(tx, TXG_WAIT);
 850                 if (error) {
 851                         dmu_tx_abort(tx);
 852                         if (abuf != NULL)
 853                                 dmu_return_arcbuf(abuf);
 854                         break;
 855                 }
 856 
 857                 /*
 858                  * If zfs_range_lock() over-locked we grow the blocksize
 859                  * and then reduce the lock range.  This will only happen
 860                  * on the first iteration since zfs_range_reduce() will
 861                  * shrink down r_len to the appropriate size.
 862                  */
 863                 if (rl->r_len == UINT64_MAX) {
 864                         uint64_t new_blksz;
 865 
 866                         if (zp->z_blksz > max_blksz) {
 867                                 /*
 868                                  * File's blocksize is already larger than the
 869                                  * "recordsize" property.  Only let it grow to
 870                                  * the next power of 2.
 871                                  */
 872                                 ASSERT(!ISP2(zp->z_blksz));
 873                                 new_blksz = MIN(end_size,
 874                                     1 << highbit64(zp->z_blksz));
 875                         } else {
 876                                 new_blksz = MIN(end_size, max_blksz);
 877                         }
 878                         zfs_grow_blocksize(zp, new_blksz, tx);
 879                         zfs_range_reduce(rl, woff, n);
 880                 }
 881 
 882                 /*
 883                  * XXX - should we really limit each write to z_max_blksz?
 884                  * Perhaps we should use SPA_MAXBLOCKSIZE chunks?
 885                  */
 886                 nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz));
 887 
 888                 if (abuf == NULL) {
 889                         tx_bytes = uio->uio_resid;
 890                         error = dmu_write_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 891                             uio, nbytes, tx);
 892                         tx_bytes -= uio->uio_resid;
 893                 } else {
 894                         tx_bytes = nbytes;
 895                         ASSERT(xuio == NULL || tx_bytes == aiov->iov_len);
 896                         /*
 897                          * If this is not a full block write, but we are
 898                          * extending the file past EOF and this data starts
 899                          * block-aligned, use assign_arcbuf().  Otherwise,
 900                          * write via dmu_write().
 901                          */
 902                         if (tx_bytes < max_blksz && (!write_eof ||
 903                             aiov->iov_base != abuf->b_data)) {
 904                                 ASSERT(xuio);
 905                                 dmu_write(zfsvfs->z_os, zp->z_id, woff,
 906                                     aiov->iov_len, aiov->iov_base, tx);
 907                                 dmu_return_arcbuf(abuf);
 908                                 xuio_stat_wbuf_copied();
 909                         } else {
 910                                 ASSERT(xuio || tx_bytes == max_blksz);
 911                                 dmu_assign_arcbuf(sa_get_db(zp->z_sa_hdl),
 912                                     woff, abuf, tx);
 913                         }
 914                         ASSERT(tx_bytes <= uio->uio_resid);
 915                         uioskip(uio, tx_bytes);
 916                 }
 917                 if (tx_bytes && vn_has_cached_data(vp)) {
 918                         update_pages(vp, woff,
 919                             tx_bytes, zfsvfs->z_os, zp->z_id);
 920                 }
 921 
 922                 /*
 923                  * If we made no progress, we're done.  If we made even
 924                  * partial progress, update the znode and ZIL accordingly.
 925                  */
 926                 if (tx_bytes == 0) {
 927                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
 928                             (void *)&zp->z_size, sizeof (uint64_t), tx);
 929                         dmu_tx_commit(tx);
 930                         ASSERT(error != 0);
 931                         break;
 932                 }
 933 
 934                 /*
 935                  * Clear Set-UID/Set-GID bits on successful write if not
 936                  * privileged and at least one of the excute bits is set.
 937                  *
 938                  * It would be nice to to this after all writes have
 939                  * been done, but that would still expose the ISUID/ISGID
 940                  * to another app after the partial write is committed.
 941                  *
 942                  * Note: we don't call zfs_fuid_map_id() here because
 943                  * user 0 is not an ephemeral uid.
 944                  */
 945                 mutex_enter(&zp->z_acl_lock);
 946                 if ((zp->z_mode & (S_IXUSR | (S_IXUSR >> 3) |
 947                     (S_IXUSR >> 6))) != 0 &&
 948                     (zp->z_mode & (S_ISUID | S_ISGID)) != 0 &&
 949                     secpolicy_vnode_setid_retain(cr,
 950                     (zp->z_mode & S_ISUID) != 0 && zp->z_uid == 0) != 0) {
 951                         uint64_t newmode;
 952                         zp->z_mode &= ~(S_ISUID | S_ISGID);
 953                         newmode = zp->z_mode;
 954                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_MODE(zfsvfs),
 955                             (void *)&newmode, sizeof (uint64_t), tx);
 956                 }
 957                 mutex_exit(&zp->z_acl_lock);
 958 
 959                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
 960                     B_TRUE);
 961 
 962                 /*
 963                  * Update the file size (zp_size) if it has changed;
 964                  * account for possible concurrent updates.
 965                  */
 966                 while ((end_size = zp->z_size) < uio->uio_loffset) {
 967                         (void) atomic_cas_64(&zp->z_size, end_size,
 968                             uio->uio_loffset);
 969                         ASSERT(error == 0);
 970                 }
 971                 /*
 972                  * If we are replaying and eof is non zero then force
 973                  * the file size to the specified eof. Note, there's no
 974                  * concurrency during replay.
 975                  */
 976                 if (zfsvfs->z_replay && zfsvfs->z_replay_eof != 0)
 977                         zp->z_size = zfsvfs->z_replay_eof;
 978 
 979                 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
 980 
 981                 zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag);
 982                 dmu_tx_commit(tx);
 983 
 984                 if (error != 0)
 985                         break;
 986                 ASSERT(tx_bytes == nbytes);
 987                 n -= nbytes;
 988 
 989                 if (!xuio && n > 0)
 990                         uio_prefaultpages(MIN(n, max_blksz), uio);
 991         }
 992 
 993         zfs_range_unlock(rl);
 994 
 995         /*
 996          * If we're in replay mode, or we made no progress, return error.
 997          * Otherwise, it's at least a partial write, so it's successful.
 998          */
 999         if (zfsvfs->z_replay || uio->uio_resid == start_resid) {
1000                 ZFS_EXIT(zfsvfs);
1001                 return (error);
1002         }
1003 
1004         if (ioflag & (FSYNC | FDSYNC) ||
1005             zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1006                 zil_commit(zilog, zp->z_id);
1007 
1008         ZFS_EXIT(zfsvfs);
1009         return (0);
1010 }
1011 
1012 void
1013 zfs_get_done(zgd_t *zgd, int error)
1014 {
1015         znode_t *zp = zgd->zgd_private;
1016         objset_t *os = zp->z_zfsvfs->z_os;
1017 
1018         if (zgd->zgd_db)
1019                 dmu_buf_rele(zgd->zgd_db, zgd);
1020 
1021         zfs_range_unlock(zgd->zgd_rl);
1022 
1023         /*
1024          * Release the vnode asynchronously as we currently have the
1025          * txg stopped from syncing.
1026          */
1027         VN_RELE_ASYNC(ZTOV(zp), dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1028 
1029         if (error == 0 && zgd->zgd_bp)
1030                 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
1031 
1032         kmem_free(zgd, sizeof (zgd_t));
1033 }
1034 
1035 #ifdef DEBUG
1036 static int zil_fault_io = 0;
1037 #endif
1038 
1039 /*
1040  * Get data to generate a TX_WRITE intent log record.
1041  */
1042 int
1043 zfs_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
1044 {
1045         zfsvfs_t *zfsvfs = arg;
1046         objset_t *os = zfsvfs->z_os;
1047         znode_t *zp;
1048         uint64_t object = lr->lr_foid;
1049         uint64_t offset = lr->lr_offset;
1050         uint64_t size = lr->lr_length;
1051         blkptr_t *bp = &lr->lr_blkptr;
1052         dmu_buf_t *db;
1053         zgd_t *zgd;
1054         int error = 0;
1055 
1056         ASSERT(zio != NULL);
1057         ASSERT(size != 0);
1058 
1059         /*
1060          * Nothing to do if the file has been removed
1061          */
1062         if (zfs_zget(zfsvfs, object, &zp) != 0)
1063                 return (SET_ERROR(ENOENT));
1064         if (zp->z_unlinked) {
1065                 /*
1066                  * Release the vnode asynchronously as we currently have the
1067                  * txg stopped from syncing.
1068                  */
1069                 VN_RELE_ASYNC(ZTOV(zp),
1070                     dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1071                 return (SET_ERROR(ENOENT));
1072         }
1073 
1074         zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1075         zgd->zgd_zilog = zfsvfs->z_log;
1076         zgd->zgd_private = zp;
1077 
1078         /*
1079          * Write records come in two flavors: immediate and indirect.
1080          * For small writes it's cheaper to store the data with the
1081          * log record (immediate); for large writes it's cheaper to
1082          * sync the data and get a pointer to it (indirect) so that
1083          * we don't have to write the data twice.
1084          */
1085         if (buf != NULL) { /* immediate write */
1086                 zgd->zgd_rl = zfs_range_lock(zp, offset, size, RL_READER);
1087                 /* test for truncation needs to be done while range locked */
1088                 if (offset >= zp->z_size) {
1089                         error = SET_ERROR(ENOENT);
1090                 } else {
1091                         error = dmu_read(os, object, offset, size, buf,
1092                             DMU_READ_NO_PREFETCH);
1093                 }
1094                 ASSERT(error == 0 || error == ENOENT);
1095         } else { /* indirect write */
1096                 /*
1097                  * Have to lock the whole block to ensure when it's
1098                  * written out and it's checksum is being calculated
1099                  * that no one can change the data. We need to re-check
1100                  * blocksize after we get the lock in case it's changed!
1101                  */
1102                 for (;;) {
1103                         uint64_t blkoff;
1104                         size = zp->z_blksz;
1105                         blkoff = ISP2(size) ? P2PHASE(offset, size) : offset;
1106                         offset -= blkoff;
1107                         zgd->zgd_rl = zfs_range_lock(zp, offset, size,
1108                             RL_READER);
1109                         if (zp->z_blksz == size)
1110                                 break;
1111                         offset += blkoff;
1112                         zfs_range_unlock(zgd->zgd_rl);
1113                 }
1114                 /* test for truncation needs to be done while range locked */
1115                 if (lr->lr_offset >= zp->z_size)
1116                         error = SET_ERROR(ENOENT);
1117 #ifdef DEBUG
1118                 if (zil_fault_io) {
1119                         error = SET_ERROR(EIO);
1120                         zil_fault_io = 0;
1121                 }
1122 #endif
1123                 if (error == 0)
1124                         error = dmu_buf_hold(os, object, offset, zgd, &db,
1125                             DMU_READ_NO_PREFETCH);
1126 
1127                 if (error == 0) {
1128                         blkptr_t *obp = dmu_buf_get_blkptr(db);
1129                         if (obp) {
1130                                 ASSERT(BP_IS_HOLE(bp));
1131                                 *bp = *obp;
1132                         }
1133 
1134                         zgd->zgd_db = db;
1135                         zgd->zgd_bp = bp;
1136 
1137                         ASSERT(db->db_offset == offset);
1138                         ASSERT(db->db_size == size);
1139 
1140                         error = dmu_sync(zio, lr->lr_common.lrc_txg,
1141                             zfs_get_done, zgd);
1142                         ASSERT(error || lr->lr_length <= zp->z_blksz);
1143 
1144                         /*
1145                          * On success, we need to wait for the write I/O
1146                          * initiated by dmu_sync() to complete before we can
1147                          * release this dbuf.  We will finish everything up
1148                          * in the zfs_get_done() callback.
1149                          */
1150                         if (error == 0)
1151                                 return (0);
1152 
1153                         if (error == EALREADY) {
1154                                 lr->lr_common.lrc_txtype = TX_WRITE2;
1155                                 error = 0;
1156                         }
1157                 }
1158         }
1159 
1160         zfs_get_done(zgd, error);
1161 
1162         return (error);
1163 }
1164 
1165 /*ARGSUSED*/
1166 static int
1167 zfs_access(vnode_t *vp, int mode, int flag, cred_t *cr,
1168     caller_context_t *ct)
1169 {
1170         znode_t *zp = VTOZ(vp);
1171         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1172         int error;
1173 
1174         ZFS_ENTER(zfsvfs);
1175         ZFS_VERIFY_ZP(zp);
1176 
1177         if (flag & V_ACE_MASK)
1178                 error = zfs_zaccess(zp, mode, flag, B_FALSE, cr);
1179         else
1180                 error = zfs_zaccess_rwx(zp, mode, flag, cr);
1181 
1182         ZFS_EXIT(zfsvfs);
1183         return (error);
1184 }
1185 
1186 /*
1187  * If vnode is for a device return a specfs vnode instead.
1188  */
1189 static int
1190 specvp_check(vnode_t **vpp, cred_t *cr)
1191 {
1192         int error = 0;
1193 
1194         if (IS_DEVVP(*vpp)) {
1195                 struct vnode *svp;
1196 
1197                 svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
1198                 VN_RELE(*vpp);
1199                 if (svp == NULL)
1200                         error = SET_ERROR(ENOSYS);
1201                 *vpp = svp;
1202         }
1203         return (error);
1204 }
1205 
1206 
1207 /*
1208  * Lookup an entry in a directory, or an extended attribute directory.
1209  * If it exists, return a held vnode reference for it.
1210  *
1211  *      IN:     dvp     - vnode of directory to search.
1212  *              nm      - name of entry to lookup.
1213  *              pnp     - full pathname to lookup [UNUSED].
1214  *              flags   - LOOKUP_XATTR set if looking for an attribute.
1215  *              rdir    - root directory vnode [UNUSED].
1216  *              cr      - credentials of caller.
1217  *              ct      - caller context
1218  *              direntflags - directory lookup flags
1219  *              realpnp - returned pathname.
1220  *
1221  *      OUT:    vpp     - vnode of located entry, NULL if not found.
1222  *
1223  *      RETURN: 0 on success, error code on failure.
1224  *
1225  * Timestamps:
1226  *      NA
1227  */
1228 /* ARGSUSED */
1229 static int
1230 zfs_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, struct pathname *pnp,
1231     int flags, vnode_t *rdir, cred_t *cr,  caller_context_t *ct,
1232     int *direntflags, pathname_t *realpnp)
1233 {
1234         znode_t *zdp = VTOZ(dvp);
1235         zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1236         int     error = 0;
1237 
1238         /* fast path */
1239         if (!(flags & (LOOKUP_XATTR | FIGNORECASE))) {
1240 
1241                 if (dvp->v_type != VDIR) {
1242                         return (SET_ERROR(ENOTDIR));
1243                 } else if (zdp->z_sa_hdl == NULL) {
1244                         return (SET_ERROR(EIO));
1245                 }
1246 
1247                 if (nm[0] == 0 || (nm[0] == '.' && nm[1] == '\0')) {
1248                         error = zfs_fastaccesschk_execute(zdp, cr);
1249                         if (!error) {
1250                                 *vpp = dvp;
1251                                 VN_HOLD(*vpp);
1252                                 return (0);
1253                         }
1254                         return (error);
1255                 } else {
1256                         vnode_t *tvp = dnlc_lookup(dvp, nm);
1257 
1258                         if (tvp) {
1259                                 error = zfs_fastaccesschk_execute(zdp, cr);
1260                                 if (error) {
1261                                         VN_RELE(tvp);
1262                                         return (error);
1263                                 }
1264                                 if (tvp == DNLC_NO_VNODE) {
1265                                         VN_RELE(tvp);
1266                                         return (SET_ERROR(ENOENT));
1267                                 } else {
1268                                         *vpp = tvp;
1269                                         return (specvp_check(vpp, cr));
1270                                 }
1271                         }
1272                 }
1273         }
1274 
1275         DTRACE_PROBE2(zfs__fastpath__lookup__miss, vnode_t *, dvp, char *, nm);
1276 
1277         ZFS_ENTER(zfsvfs);
1278         ZFS_VERIFY_ZP(zdp);
1279 
1280         *vpp = NULL;
1281 
1282         if (flags & LOOKUP_XATTR) {
1283                 /*
1284                  * If the xattr property is off, refuse the lookup request.
1285                  */
1286                 if (!(zfsvfs->z_vfs->vfs_flag & VFS_XATTR)) {
1287                         ZFS_EXIT(zfsvfs);
1288                         return (SET_ERROR(EINVAL));
1289                 }
1290 
1291                 /*
1292                  * We don't allow recursive attributes..
1293                  * Maybe someday we will.
1294                  */
1295                 if (zdp->z_pflags & ZFS_XATTR) {
1296                         ZFS_EXIT(zfsvfs);
1297                         return (SET_ERROR(EINVAL));
1298                 }
1299 
1300                 if (error = zfs_get_xattrdir(VTOZ(dvp), vpp, cr, flags)) {
1301                         ZFS_EXIT(zfsvfs);
1302                         return (error);
1303                 }
1304 
1305                 /*
1306                  * Do we have permission to get into attribute directory?
1307                  */
1308 
1309                 if (error = zfs_zaccess(VTOZ(*vpp), ACE_EXECUTE, 0,
1310                     B_FALSE, cr)) {
1311                         VN_RELE(*vpp);
1312                         *vpp = NULL;
1313                 }
1314 
1315                 ZFS_EXIT(zfsvfs);
1316                 return (error);
1317         }
1318 
1319         if (dvp->v_type != VDIR) {
1320                 ZFS_EXIT(zfsvfs);
1321                 return (SET_ERROR(ENOTDIR));
1322         }
1323 
1324         /*
1325          * Check accessibility of directory.
1326          */
1327 
1328         if (error = zfs_zaccess(zdp, ACE_EXECUTE, 0, B_FALSE, cr)) {
1329                 ZFS_EXIT(zfsvfs);
1330                 return (error);
1331         }
1332 
1333         if (zfsvfs->z_utf8 && u8_validate(nm, strlen(nm),
1334             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1335                 ZFS_EXIT(zfsvfs);
1336                 return (SET_ERROR(EILSEQ));
1337         }
1338 
1339         error = zfs_dirlook(zdp, nm, vpp, flags, direntflags, realpnp);
1340         if (error == 0)
1341                 error = specvp_check(vpp, cr);
1342 
1343         ZFS_EXIT(zfsvfs);
1344         return (error);
1345 }
1346 
1347 /*
1348  * Attempt to create a new entry in a directory.  If the entry
1349  * already exists, truncate the file if permissible, else return
1350  * an error.  Return the vp of the created or trunc'd file.
1351  *
1352  *      IN:     dvp     - vnode of directory to put new file entry in.
1353  *              name    - name of new file entry.
1354  *              vap     - attributes of new file.
1355  *              excl    - flag indicating exclusive or non-exclusive mode.
1356  *              mode    - mode to open file with.
1357  *              cr      - credentials of caller.
1358  *              flag    - large file flag [UNUSED].
1359  *              ct      - caller context
1360  *              vsecp   - ACL to be set
1361  *
1362  *      OUT:    vpp     - vnode of created or trunc'd entry.
1363  *
1364  *      RETURN: 0 on success, error code on failure.
1365  *
1366  * Timestamps:
1367  *      dvp - ctime|mtime updated if new entry created
1368  *       vp - ctime|mtime always, atime if new
1369  */
1370 
1371 /* ARGSUSED */
1372 static int
1373 zfs_create(vnode_t *dvp, char *name, vattr_t *vap, vcexcl_t excl,
1374     int mode, vnode_t **vpp, cred_t *cr, int flag, caller_context_t *ct,
1375     vsecattr_t *vsecp)
1376 {
1377         znode_t         *zp, *dzp = VTOZ(dvp);
1378         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1379         zilog_t         *zilog;
1380         objset_t        *os;
1381         zfs_dirlock_t   *dl;
1382         dmu_tx_t        *tx;
1383         int             error;
1384         ksid_t          *ksid;
1385         uid_t           uid;
1386         gid_t           gid = crgetgid(cr);
1387         zfs_acl_ids_t   acl_ids;
1388         boolean_t       fuid_dirtied;
1389         boolean_t       have_acl = B_FALSE;
1390         boolean_t       waited = B_FALSE;
1391 
1392         /*
1393          * If we have an ephemeral id, ACL, or XVATTR then
1394          * make sure file system is at proper version
1395          */
1396 
1397         ksid = crgetsid(cr, KSID_OWNER);
1398         if (ksid)
1399                 uid = ksid_getid(ksid);
1400         else
1401                 uid = crgetuid(cr);
1402 
1403         if (zfsvfs->z_use_fuids == B_FALSE &&
1404             (vsecp || (vap->va_mask & AT_XVATTR) ||
1405             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
1406                 return (SET_ERROR(EINVAL));
1407 
1408         ZFS_ENTER(zfsvfs);
1409         ZFS_VERIFY_ZP(dzp);
1410         os = zfsvfs->z_os;
1411         zilog = zfsvfs->z_log;
1412 
1413         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
1414             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1415                 ZFS_EXIT(zfsvfs);
1416                 return (SET_ERROR(EILSEQ));
1417         }
1418 
1419         if (vap->va_mask & AT_XVATTR) {
1420                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
1421                     crgetuid(cr), cr, vap->va_type)) != 0) {
1422                         ZFS_EXIT(zfsvfs);
1423                         return (error);
1424                 }
1425         }
1426 top:
1427         *vpp = NULL;
1428 
1429         if ((vap->va_mode & VSVTX) && secpolicy_vnode_stky_modify(cr))
1430                 vap->va_mode &= ~VSVTX;
1431 
1432         if (*name == '\0') {
1433                 /*
1434                  * Null component name refers to the directory itself.
1435                  */
1436                 VN_HOLD(dvp);
1437                 zp = dzp;
1438                 dl = NULL;
1439                 error = 0;
1440         } else {
1441                 /* possible VN_HOLD(zp) */
1442                 int zflg = 0;
1443 
1444                 if (flag & FIGNORECASE)
1445                         zflg |= ZCILOOK;
1446 
1447                 error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1448                     NULL, NULL);
1449                 if (error) {
1450                         if (have_acl)
1451                                 zfs_acl_ids_free(&acl_ids);
1452                         if (strcmp(name, "..") == 0)
1453                                 error = SET_ERROR(EISDIR);
1454                         ZFS_EXIT(zfsvfs);
1455                         return (error);
1456                 }
1457         }
1458 
1459         if (zp == NULL) {
1460                 uint64_t txtype;
1461 
1462                 /*
1463                  * Create a new file object and update the directory
1464                  * to reference it.
1465                  */
1466                 if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
1467                         if (have_acl)
1468                                 zfs_acl_ids_free(&acl_ids);
1469                         goto out;
1470                 }
1471 
1472                 /*
1473                  * We only support the creation of regular files in
1474                  * extended attribute directories.
1475                  */
1476 
1477                 if ((dzp->z_pflags & ZFS_XATTR) &&
1478                     (vap->va_type != VREG)) {
1479                         if (have_acl)
1480                                 zfs_acl_ids_free(&acl_ids);
1481                         error = SET_ERROR(EINVAL);
1482                         goto out;
1483                 }
1484 
1485                 if (!have_acl && (error = zfs_acl_ids_create(dzp, 0, vap,
1486                     cr, vsecp, &acl_ids)) != 0)
1487                         goto out;
1488                 have_acl = B_TRUE;
1489 
1490                 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
1491                         zfs_acl_ids_free(&acl_ids);
1492                         error = SET_ERROR(EDQUOT);
1493                         goto out;
1494                 }
1495 
1496                 tx = dmu_tx_create(os);
1497 
1498                 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1499                     ZFS_SA_BASE_ATTR_SIZE);
1500 
1501                 fuid_dirtied = zfsvfs->z_fuid_dirty;
1502                 if (fuid_dirtied)
1503                         zfs_fuid_txhold(zfsvfs, tx);
1504                 dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
1505                 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
1506                 if (!zfsvfs->z_use_sa &&
1507                     acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
1508                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
1509                             0, acl_ids.z_aclp->z_acl_bytes);
1510                 }
1511                 error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1512                 if (error) {
1513                         zfs_dirent_unlock(dl);
1514                         if (error == ERESTART) {
1515                                 waited = B_TRUE;
1516                                 dmu_tx_wait(tx);
1517                                 dmu_tx_abort(tx);
1518                                 goto top;
1519                         }
1520                         zfs_acl_ids_free(&acl_ids);
1521                         dmu_tx_abort(tx);
1522                         ZFS_EXIT(zfsvfs);
1523                         return (error);
1524                 }
1525                 zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
1526 
1527                 if (fuid_dirtied)
1528                         zfs_fuid_sync(zfsvfs, tx);
1529 
1530                 (void) zfs_link_create(dl, zp, tx, ZNEW);
1531                 txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
1532                 if (flag & FIGNORECASE)
1533                         txtype |= TX_CI;
1534                 zfs_log_create(zilog, tx, txtype, dzp, zp, name,
1535                     vsecp, acl_ids.z_fuidp, vap);
1536                 zfs_acl_ids_free(&acl_ids);
1537                 dmu_tx_commit(tx);
1538         } else {
1539                 int aflags = (flag & FAPPEND) ? V_APPEND : 0;
1540 
1541                 if (have_acl)
1542                         zfs_acl_ids_free(&acl_ids);
1543                 have_acl = B_FALSE;
1544 
1545                 /*
1546                  * A directory entry already exists for this name.
1547                  */
1548                 /*
1549                  * Can't truncate an existing file if in exclusive mode.
1550                  */
1551                 if (excl == EXCL) {
1552                         error = SET_ERROR(EEXIST);
1553                         goto out;
1554                 }
1555                 /*
1556                  * Can't open a directory for writing.
1557                  */
1558                 if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) {
1559                         error = SET_ERROR(EISDIR);
1560                         goto out;
1561                 }
1562                 /*
1563                  * Verify requested access to file.
1564                  */
1565                 if (mode && (error = zfs_zaccess_rwx(zp, mode, aflags, cr))) {
1566                         goto out;
1567                 }
1568 
1569                 mutex_enter(&dzp->z_lock);
1570                 dzp->z_seq++;
1571                 mutex_exit(&dzp->z_lock);
1572 
1573                 /*
1574                  * Truncate regular files if requested.
1575                  */
1576                 if ((ZTOV(zp)->v_type == VREG) &&
1577                     (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) {
1578                         /* we can't hold any locks when calling zfs_freesp() */
1579                         zfs_dirent_unlock(dl);
1580                         dl = NULL;
1581                         error = zfs_freesp(zp, 0, 0, mode, TRUE);
1582                         if (error == 0) {
1583                                 vnevent_create(ZTOV(zp), ct);
1584                         }
1585                 }
1586         }
1587 out:
1588 
1589         if (dl)
1590                 zfs_dirent_unlock(dl);
1591 
1592         if (error) {
1593                 if (zp)
1594                         VN_RELE(ZTOV(zp));
1595         } else {
1596                 *vpp = ZTOV(zp);
1597                 error = specvp_check(vpp, cr);
1598         }
1599 
1600         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1601                 zil_commit(zilog, 0);
1602 
1603         ZFS_EXIT(zfsvfs);
1604         return (error);
1605 }
1606 
1607 /*
1608  * Remove an entry from a directory.
1609  *
1610  *      IN:     dvp     - vnode of directory to remove entry from.
1611  *              name    - name of entry to remove.
1612  *              cr      - credentials of caller.
1613  *              ct      - caller context
1614  *              flags   - case flags
1615  *
1616  *      RETURN: 0 on success, error code on failure.
1617  *
1618  * Timestamps:
1619  *      dvp - ctime|mtime
1620  *       vp - ctime (if nlink > 0)
1621  */
1622 
1623 uint64_t null_xattr = 0;
1624 
1625 /*ARGSUSED*/
1626 static int
1627 zfs_remove(vnode_t *dvp, char *name, cred_t *cr, caller_context_t *ct,
1628     int flags)
1629 {
1630         znode_t         *zp, *dzp = VTOZ(dvp);
1631         znode_t         *xzp;
1632         vnode_t         *vp;
1633         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1634         zilog_t         *zilog;
1635         uint64_t        acl_obj, xattr_obj;
1636         uint64_t        xattr_obj_unlinked = 0;
1637         uint64_t        obj = 0;
1638         zfs_dirlock_t   *dl;
1639         dmu_tx_t        *tx;
1640         boolean_t       may_delete_now, delete_now = FALSE;
1641         boolean_t       unlinked, toobig = FALSE;
1642         uint64_t        txtype;
1643         pathname_t      *realnmp = NULL;
1644         pathname_t      realnm;
1645         int             error;
1646         int             zflg = ZEXISTS;
1647         boolean_t       waited = B_FALSE;
1648 
1649         ZFS_ENTER(zfsvfs);
1650         ZFS_VERIFY_ZP(dzp);
1651         zilog = zfsvfs->z_log;
1652 
1653         if (flags & FIGNORECASE) {
1654                 zflg |= ZCILOOK;
1655                 pn_alloc(&realnm);
1656                 realnmp = &realnm;
1657         }
1658 
1659 top:
1660         xattr_obj = 0;
1661         xzp = NULL;
1662         /*
1663          * Attempt to lock directory; fail if entry doesn't exist.
1664          */
1665         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1666             NULL, realnmp)) {
1667                 if (realnmp)
1668                         pn_free(realnmp);
1669                 ZFS_EXIT(zfsvfs);
1670                 return (error);
1671         }
1672 
1673         vp = ZTOV(zp);
1674 
1675         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
1676                 goto out;
1677         }
1678 
1679         /*
1680          * Need to use rmdir for removing directories.
1681          */
1682         if (vp->v_type == VDIR) {
1683                 error = SET_ERROR(EPERM);
1684                 goto out;
1685         }
1686 
1687         vnevent_remove(vp, dvp, name, ct);
1688 
1689         if (realnmp)
1690                 dnlc_remove(dvp, realnmp->pn_buf);
1691         else
1692                 dnlc_remove(dvp, name);
1693 
1694         mutex_enter(&vp->v_lock);
1695         may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp);
1696         mutex_exit(&vp->v_lock);
1697 
1698         /*
1699          * We may delete the znode now, or we may put it in the unlinked set;
1700          * it depends on whether we're the last link, and on whether there are
1701          * other holds on the vnode.  So we dmu_tx_hold() the right things to
1702          * allow for either case.
1703          */
1704         obj = zp->z_id;
1705         tx = dmu_tx_create(zfsvfs->z_os);
1706         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
1707         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
1708         zfs_sa_upgrade_txholds(tx, zp);
1709         zfs_sa_upgrade_txholds(tx, dzp);
1710         if (may_delete_now) {
1711                 toobig =
1712                     zp->z_size > zp->z_blksz * DMU_MAX_DELETEBLKCNT;
1713                 /* if the file is too big, only hold_free a token amount */
1714                 dmu_tx_hold_free(tx, zp->z_id, 0,
1715                     (toobig ? DMU_MAX_ACCESS : DMU_OBJECT_END));
1716         }
1717 
1718         /* are there any extended attributes? */
1719         error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
1720             &xattr_obj, sizeof (xattr_obj));
1721         if (error == 0 && xattr_obj) {
1722                 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
1723                 ASSERT0(error);
1724                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
1725                 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
1726         }
1727 
1728         mutex_enter(&zp->z_lock);
1729         if ((acl_obj = zfs_external_acl(zp)) != 0 && may_delete_now)
1730                 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
1731         mutex_exit(&zp->z_lock);
1732 
1733         /* charge as an update -- would be nice not to charge at all */
1734         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
1735 
1736         /*
1737          * Mark this transaction as typically resulting in a net free of
1738          * space, unless object removal will be delayed indefinitely
1739          * (due to active holds on the vnode due to the file being open).
1740          */
1741         if (may_delete_now)
1742                 dmu_tx_mark_netfree(tx);
1743 
1744         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1745         if (error) {
1746                 zfs_dirent_unlock(dl);
1747                 VN_RELE(vp);
1748                 if (xzp)
1749                         VN_RELE(ZTOV(xzp));
1750                 if (error == ERESTART) {
1751                         waited = B_TRUE;
1752                         dmu_tx_wait(tx);
1753                         dmu_tx_abort(tx);
1754                         goto top;
1755                 }
1756                 if (realnmp)
1757                         pn_free(realnmp);
1758                 dmu_tx_abort(tx);
1759                 ZFS_EXIT(zfsvfs);
1760                 return (error);
1761         }
1762 
1763         /*
1764          * Remove the directory entry.
1765          */
1766         error = zfs_link_destroy(dl, zp, tx, zflg, &unlinked);
1767 
1768         if (error) {
1769                 dmu_tx_commit(tx);
1770                 goto out;
1771         }
1772 
1773         if (unlinked) {
1774                 /*
1775                  * Hold z_lock so that we can make sure that the ACL obj
1776                  * hasn't changed.  Could have been deleted due to
1777                  * zfs_sa_upgrade().
1778                  */
1779                 mutex_enter(&zp->z_lock);
1780                 mutex_enter(&vp->v_lock);
1781                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
1782                     &xattr_obj_unlinked, sizeof (xattr_obj_unlinked));
1783                 delete_now = may_delete_now && !toobig &&
1784                     vp->v_count == 1 && !vn_has_cached_data(vp) &&
1785                     xattr_obj == xattr_obj_unlinked && zfs_external_acl(zp) ==
1786                     acl_obj;
1787                 mutex_exit(&vp->v_lock);
1788         }
1789 
1790         if (delete_now) {
1791                 if (xattr_obj_unlinked) {
1792                         ASSERT3U(xzp->z_links, ==, 2);
1793                         mutex_enter(&xzp->z_lock);
1794                         xzp->z_unlinked = 1;
1795                         xzp->z_links = 0;
1796                         error = sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
1797                             &xzp->z_links, sizeof (xzp->z_links), tx);
1798                         ASSERT3U(error,  ==,  0);
1799                         mutex_exit(&xzp->z_lock);
1800                         zfs_unlinked_add(xzp, tx);
1801 
1802                         if (zp->z_is_sa)
1803                                 error = sa_remove(zp->z_sa_hdl,
1804                                     SA_ZPL_XATTR(zfsvfs), tx);
1805                         else
1806                                 error = sa_update(zp->z_sa_hdl,
1807                                     SA_ZPL_XATTR(zfsvfs), &null_xattr,
1808                                     sizeof (uint64_t), tx);
1809                         ASSERT0(error);
1810                 }
1811                 mutex_enter(&vp->v_lock);
1812                 vp->v_count--;
1813                 ASSERT0(vp->v_count);
1814                 mutex_exit(&vp->v_lock);
1815                 mutex_exit(&zp->z_lock);
1816                 zfs_znode_delete(zp, tx);
1817         } else if (unlinked) {
1818                 mutex_exit(&zp->z_lock);
1819                 zfs_unlinked_add(zp, tx);
1820         }
1821 
1822         txtype = TX_REMOVE;
1823         if (flags & FIGNORECASE)
1824                 txtype |= TX_CI;
1825         zfs_log_remove(zilog, tx, txtype, dzp, name, obj);
1826 
1827         dmu_tx_commit(tx);
1828 out:
1829         if (realnmp)
1830                 pn_free(realnmp);
1831 
1832         zfs_dirent_unlock(dl);
1833 
1834         if (!delete_now)
1835                 VN_RELE(vp);
1836         if (xzp)
1837                 VN_RELE(ZTOV(xzp));
1838 
1839         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1840                 zil_commit(zilog, 0);
1841 
1842         ZFS_EXIT(zfsvfs);
1843         return (error);
1844 }
1845 
1846 /*
1847  * Create a new directory and insert it into dvp using the name
1848  * provided.  Return a pointer to the inserted directory.
1849  *
1850  *      IN:     dvp     - vnode of directory to add subdir to.
1851  *              dirname - name of new directory.
1852  *              vap     - attributes of new directory.
1853  *              cr      - credentials of caller.
1854  *              ct      - caller context
1855  *              flags   - case flags
1856  *              vsecp   - ACL to be set
1857  *
1858  *      OUT:    vpp     - vnode of created directory.
1859  *
1860  *      RETURN: 0 on success, error code on failure.
1861  *
1862  * Timestamps:
1863  *      dvp - ctime|mtime updated
1864  *       vp - ctime|mtime|atime updated
1865  */
1866 /*ARGSUSED*/
1867 static int
1868 zfs_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, cred_t *cr,
1869     caller_context_t *ct, int flags, vsecattr_t *vsecp)
1870 {
1871         znode_t         *zp, *dzp = VTOZ(dvp);
1872         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1873         zilog_t         *zilog;
1874         zfs_dirlock_t   *dl;
1875         uint64_t        txtype;
1876         dmu_tx_t        *tx;
1877         int             error;
1878         int             zf = ZNEW;
1879         ksid_t          *ksid;
1880         uid_t           uid;
1881         gid_t           gid = crgetgid(cr);
1882         zfs_acl_ids_t   acl_ids;
1883         boolean_t       fuid_dirtied;
1884         boolean_t       waited = B_FALSE;
1885 
1886         ASSERT(vap->va_type == VDIR);
1887 
1888         /*
1889          * If we have an ephemeral id, ACL, or XVATTR then
1890          * make sure file system is at proper version
1891          */
1892 
1893         ksid = crgetsid(cr, KSID_OWNER);
1894         if (ksid)
1895                 uid = ksid_getid(ksid);
1896         else
1897                 uid = crgetuid(cr);
1898         if (zfsvfs->z_use_fuids == B_FALSE &&
1899             (vsecp || (vap->va_mask & AT_XVATTR) ||
1900             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
1901                 return (SET_ERROR(EINVAL));
1902 
1903         ZFS_ENTER(zfsvfs);
1904         ZFS_VERIFY_ZP(dzp);
1905         zilog = zfsvfs->z_log;
1906 
1907         if (dzp->z_pflags & ZFS_XATTR) {
1908                 ZFS_EXIT(zfsvfs);
1909                 return (SET_ERROR(EINVAL));
1910         }
1911 
1912         if (zfsvfs->z_utf8 && u8_validate(dirname,
1913             strlen(dirname), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1914                 ZFS_EXIT(zfsvfs);
1915                 return (SET_ERROR(EILSEQ));
1916         }
1917         if (flags & FIGNORECASE)
1918                 zf |= ZCILOOK;
1919 
1920         if (vap->va_mask & AT_XVATTR) {
1921                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
1922                     crgetuid(cr), cr, vap->va_type)) != 0) {
1923                         ZFS_EXIT(zfsvfs);
1924                         return (error);
1925                 }
1926         }
1927 
1928         if ((error = zfs_acl_ids_create(dzp, 0, vap, cr,
1929             vsecp, &acl_ids)) != 0) {
1930                 ZFS_EXIT(zfsvfs);
1931                 return (error);
1932         }
1933         /*
1934          * First make sure the new directory doesn't exist.
1935          *
1936          * Existence is checked first to make sure we don't return
1937          * EACCES instead of EEXIST which can cause some applications
1938          * to fail.
1939          */
1940 top:
1941         *vpp = NULL;
1942 
1943         if (error = zfs_dirent_lock(&dl, dzp, dirname, &zp, zf,
1944             NULL, NULL)) {
1945                 zfs_acl_ids_free(&acl_ids);
1946                 ZFS_EXIT(zfsvfs);
1947                 return (error);
1948         }
1949 
1950         if (error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, 0, B_FALSE, cr)) {
1951                 zfs_acl_ids_free(&acl_ids);
1952                 zfs_dirent_unlock(dl);
1953                 ZFS_EXIT(zfsvfs);
1954                 return (error);
1955         }
1956 
1957         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
1958                 zfs_acl_ids_free(&acl_ids);
1959                 zfs_dirent_unlock(dl);
1960                 ZFS_EXIT(zfsvfs);
1961                 return (SET_ERROR(EDQUOT));
1962         }
1963 
1964         /*
1965          * Add a new entry to the directory.
1966          */
1967         tx = dmu_tx_create(zfsvfs->z_os);
1968         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname);
1969         dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
1970         fuid_dirtied = zfsvfs->z_fuid_dirty;
1971         if (fuid_dirtied)
1972                 zfs_fuid_txhold(zfsvfs, tx);
1973         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
1974                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
1975                     acl_ids.z_aclp->z_acl_bytes);
1976         }
1977 
1978         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1979             ZFS_SA_BASE_ATTR_SIZE);
1980 
1981         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1982         if (error) {
1983                 zfs_dirent_unlock(dl);
1984                 if (error == ERESTART) {
1985                         waited = B_TRUE;
1986                         dmu_tx_wait(tx);
1987                         dmu_tx_abort(tx);
1988                         goto top;
1989                 }
1990                 zfs_acl_ids_free(&acl_ids);
1991                 dmu_tx_abort(tx);
1992                 ZFS_EXIT(zfsvfs);
1993                 return (error);
1994         }
1995 
1996         /*
1997          * Create new node.
1998          */
1999         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
2000 
2001         if (fuid_dirtied)
2002                 zfs_fuid_sync(zfsvfs, tx);
2003 
2004         /*
2005          * Now put new name in parent dir.
2006          */
2007         (void) zfs_link_create(dl, zp, tx, ZNEW);
2008 
2009         *vpp = ZTOV(zp);
2010 
2011         txtype = zfs_log_create_txtype(Z_DIR, vsecp, vap);
2012         if (flags & FIGNORECASE)
2013                 txtype |= TX_CI;
2014         zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, vsecp,
2015             acl_ids.z_fuidp, vap);
2016 
2017         zfs_acl_ids_free(&acl_ids);
2018 
2019         dmu_tx_commit(tx);
2020 
2021         zfs_dirent_unlock(dl);
2022 
2023         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2024                 zil_commit(zilog, 0);
2025 
2026         ZFS_EXIT(zfsvfs);
2027         return (0);
2028 }
2029 
2030 /*
2031  * Remove a directory subdir entry.  If the current working
2032  * directory is the same as the subdir to be removed, the
2033  * remove will fail.
2034  *
2035  *      IN:     dvp     - vnode of directory to remove from.
2036  *              name    - name of directory to be removed.
2037  *              cwd     - vnode of current working directory.
2038  *              cr      - credentials of caller.
2039  *              ct      - caller context
2040  *              flags   - case flags
2041  *
2042  *      RETURN: 0 on success, error code on failure.
2043  *
2044  * Timestamps:
2045  *      dvp - ctime|mtime updated
2046  */
2047 /*ARGSUSED*/
2048 static int
2049 zfs_rmdir(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
2050     caller_context_t *ct, int flags)
2051 {
2052         znode_t         *dzp = VTOZ(dvp);
2053         znode_t         *zp;
2054         vnode_t         *vp;
2055         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
2056         zilog_t         *zilog;
2057         zfs_dirlock_t   *dl;
2058         dmu_tx_t        *tx;
2059         int             error;
2060         int             zflg = ZEXISTS;
2061         boolean_t       waited = B_FALSE;
2062 
2063         ZFS_ENTER(zfsvfs);
2064         ZFS_VERIFY_ZP(dzp);
2065         zilog = zfsvfs->z_log;
2066 
2067         if (flags & FIGNORECASE)
2068                 zflg |= ZCILOOK;
2069 top:
2070         zp = NULL;
2071 
2072         /*
2073          * Attempt to lock directory; fail if entry doesn't exist.
2074          */
2075         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
2076             NULL, NULL)) {
2077                 ZFS_EXIT(zfsvfs);
2078                 return (error);
2079         }
2080 
2081         vp = ZTOV(zp);
2082 
2083         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
2084                 goto out;
2085         }
2086 
2087         if (vp->v_type != VDIR) {
2088                 error = SET_ERROR(ENOTDIR);
2089                 goto out;
2090         }
2091 
2092         if (vp == cwd) {
2093                 error = SET_ERROR(EINVAL);
2094                 goto out;
2095         }
2096 
2097         vnevent_rmdir(vp, dvp, name, ct);
2098 
2099         /*
2100          * Grab a lock on the directory to make sure that noone is
2101          * trying to add (or lookup) entries while we are removing it.
2102          */
2103         rw_enter(&zp->z_name_lock, RW_WRITER);
2104 
2105         /*
2106          * Grab a lock on the parent pointer to make sure we play well
2107          * with the treewalk and directory rename code.
2108          */
2109         rw_enter(&zp->z_parent_lock, RW_WRITER);
2110 
2111         tx = dmu_tx_create(zfsvfs->z_os);
2112         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
2113         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
2114         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
2115         zfs_sa_upgrade_txholds(tx, zp);
2116         zfs_sa_upgrade_txholds(tx, dzp);
2117         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
2118         if (error) {
2119                 rw_exit(&zp->z_parent_lock);
2120                 rw_exit(&zp->z_name_lock);
2121                 zfs_dirent_unlock(dl);
2122                 VN_RELE(vp);
2123                 if (error == ERESTART) {
2124                         waited = B_TRUE;
2125                         dmu_tx_wait(tx);
2126                         dmu_tx_abort(tx);
2127                         goto top;
2128                 }
2129                 dmu_tx_abort(tx);
2130                 ZFS_EXIT(zfsvfs);
2131                 return (error);
2132         }
2133 
2134         error = zfs_link_destroy(dl, zp, tx, zflg, NULL);
2135 
2136         if (error == 0) {
2137                 uint64_t txtype = TX_RMDIR;
2138                 if (flags & FIGNORECASE)
2139                         txtype |= TX_CI;
2140                 zfs_log_remove(zilog, tx, txtype, dzp, name, ZFS_NO_OBJECT);
2141         }
2142 
2143         dmu_tx_commit(tx);
2144 
2145         rw_exit(&zp->z_parent_lock);
2146         rw_exit(&zp->z_name_lock);
2147 out:
2148         zfs_dirent_unlock(dl);
2149 
2150         VN_RELE(vp);
2151 
2152         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2153                 zil_commit(zilog, 0);
2154 
2155         ZFS_EXIT(zfsvfs);
2156         return (error);
2157 }
2158 
2159 /*
2160  * Read as many directory entries as will fit into the provided
2161  * buffer from the given directory cursor position (specified in
2162  * the uio structure).
2163  *
2164  *      IN:     vp      - vnode of directory to read.
2165  *              uio     - structure supplying read location, range info,
2166  *                        and return buffer.
2167  *              cr      - credentials of caller.
2168  *              ct      - caller context
2169  *              flags   - case flags
2170  *
2171  *      OUT:    uio     - updated offset and range, buffer filled.
2172  *              eofp    - set to true if end-of-file detected.
2173  *
2174  *      RETURN: 0 on success, error code on failure.
2175  *
2176  * Timestamps:
2177  *      vp - atime updated
2178  *
2179  * Note that the low 4 bits of the cookie returned by zap is always zero.
2180  * This allows us to use the low range for "special" directory entries:
2181  * We use 0 for '.', and 1 for '..'.  If this is the root of the filesystem,
2182  * we use the offset 2 for the '.zfs' directory.
2183  */
2184 /* ARGSUSED */
2185 static int
2186 zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int *eofp,
2187     caller_context_t *ct, int flags)
2188 {
2189         znode_t         *zp = VTOZ(vp);
2190         iovec_t         *iovp;
2191         edirent_t       *eodp;
2192         dirent64_t      *odp;
2193         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
2194         objset_t        *os;
2195         caddr_t         outbuf;
2196         size_t          bufsize;
2197         zap_cursor_t    zc;
2198         zap_attribute_t zap;
2199         uint_t          bytes_wanted;
2200         uint64_t        offset; /* must be unsigned; checks for < 1 */
2201         uint64_t        parent;
2202         int             local_eof;
2203         int             outcount;
2204         int             error;
2205         uint8_t         prefetch;
2206         boolean_t       check_sysattrs;
2207 
2208         ZFS_ENTER(zfsvfs);
2209         ZFS_VERIFY_ZP(zp);
2210 
2211         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
2212             &parent, sizeof (parent))) != 0) {
2213                 ZFS_EXIT(zfsvfs);
2214                 return (error);
2215         }
2216 
2217         /*
2218          * If we are not given an eof variable,
2219          * use a local one.
2220          */
2221         if (eofp == NULL)
2222                 eofp = &local_eof;
2223 
2224         /*
2225          * Check for valid iov_len.
2226          */
2227         if (uio->uio_iov->iov_len <= 0) {
2228                 ZFS_EXIT(zfsvfs);
2229                 return (SET_ERROR(EINVAL));
2230         }
2231 
2232         /*
2233          * Quit if directory has been removed (posix)
2234          */
2235         if ((*eofp = zp->z_unlinked) != 0) {
2236                 ZFS_EXIT(zfsvfs);
2237                 return (0);
2238         }
2239 
2240         error = 0;
2241         os = zfsvfs->z_os;
2242         offset = uio->uio_loffset;
2243         prefetch = zp->z_zn_prefetch;
2244 
2245         /*
2246          * Initialize the iterator cursor.
2247          */
2248         if (offset <= 3) {
2249                 /*
2250                  * Start iteration from the beginning of the directory.
2251                  */
2252                 zap_cursor_init(&zc, os, zp->z_id);
2253         } else {
2254                 /*
2255                  * The offset is a serialized cursor.
2256                  */
2257                 zap_cursor_init_serialized(&zc, os, zp->z_id, offset);
2258         }
2259 
2260         /*
2261          * Get space to change directory entries into fs independent format.
2262          */
2263         iovp = uio->uio_iov;
2264         bytes_wanted = iovp->iov_len;
2265         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) {
2266                 bufsize = bytes_wanted;
2267                 outbuf = kmem_alloc(bufsize, KM_SLEEP);
2268                 odp = (struct dirent64 *)outbuf;
2269         } else {
2270                 bufsize = bytes_wanted;
2271                 outbuf = NULL;
2272                 odp = (struct dirent64 *)iovp->iov_base;
2273         }
2274         eodp = (struct edirent *)odp;
2275 
2276         /*
2277          * If this VFS supports the system attribute view interface; and
2278          * we're looking at an extended attribute directory; and we care
2279          * about normalization conflicts on this vfs; then we must check
2280          * for normalization conflicts with the sysattr name space.
2281          */
2282         check_sysattrs = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
2283             (vp->v_flag & V_XATTRDIR) && zfsvfs->z_norm &&
2284             (flags & V_RDDIR_ENTFLAGS);
2285 
2286         /*
2287          * Transform to file-system independent format
2288          */
2289         outcount = 0;
2290         while (outcount < bytes_wanted) {
2291                 ino64_t objnum;
2292                 ushort_t reclen;
2293                 off64_t *next = NULL;
2294 
2295                 /*
2296                  * Special case `.', `..', and `.zfs'.
2297                  */
2298                 if (offset == 0) {
2299                         (void) strcpy(zap.za_name, ".");
2300                         zap.za_normalization_conflict = 0;
2301                         objnum = zp->z_id;
2302                 } else if (offset == 1) {
2303                         (void) strcpy(zap.za_name, "..");
2304                         zap.za_normalization_conflict = 0;
2305                         objnum = parent;
2306                 } else if (offset == 2 && zfs_show_ctldir(zp)) {
2307                         (void) strcpy(zap.za_name, ZFS_CTLDIR_NAME);
2308                         zap.za_normalization_conflict = 0;
2309                         objnum = ZFSCTL_INO_ROOT;
2310                 } else {
2311                         /*
2312                          * Grab next entry.
2313                          */
2314                         if (error = zap_cursor_retrieve(&zc, &zap)) {
2315                                 if ((*eofp = (error == ENOENT)) != 0)
2316                                         break;
2317                                 else
2318                                         goto update;
2319                         }
2320 
2321                         if (zap.za_integer_length != 8 ||
2322                             zap.za_num_integers != 1) {
2323                                 cmn_err(CE_WARN, "zap_readdir: bad directory "
2324                                     "entry, obj = %lld, offset = %lld\n",
2325                                     (u_longlong_t)zp->z_id,
2326                                     (u_longlong_t)offset);
2327                                 error = SET_ERROR(ENXIO);
2328                                 goto update;
2329                         }
2330 
2331                         objnum = ZFS_DIRENT_OBJ(zap.za_first_integer);
2332                         /*
2333                          * MacOS X can extract the object type here such as:
2334                          * uint8_t type = ZFS_DIRENT_TYPE(zap.za_first_integer);
2335                          */
2336 
2337                         if (check_sysattrs && !zap.za_normalization_conflict) {
2338                                 zap.za_normalization_conflict =
2339                                     xattr_sysattr_casechk(zap.za_name);
2340                         }
2341                 }
2342 
2343                 if (flags & V_RDDIR_ACCFILTER) {
2344                         /*
2345                          * If we have no access at all, don't include
2346                          * this entry in the returned information
2347                          */
2348                         znode_t *ezp;
2349                         if (zfs_zget(zp->z_zfsvfs, objnum, &ezp) != 0)
2350                                 goto skip_entry;
2351                         if (!zfs_has_access(ezp, cr)) {
2352                                 VN_RELE(ZTOV(ezp));
2353                                 goto skip_entry;
2354                         }
2355                         VN_RELE(ZTOV(ezp));
2356                 }
2357 
2358                 if (flags & V_RDDIR_ENTFLAGS)
2359                         reclen = EDIRENT_RECLEN(strlen(zap.za_name));
2360                 else
2361                         reclen = DIRENT64_RECLEN(strlen(zap.za_name));
2362 
2363                 /*
2364                  * Will this entry fit in the buffer?
2365                  */
2366                 if (outcount + reclen > bufsize) {
2367                         /*
2368                          * Did we manage to fit anything in the buffer?
2369                          */
2370                         if (!outcount) {
2371                                 error = SET_ERROR(EINVAL);
2372                                 goto update;
2373                         }
2374                         break;
2375                 }
2376                 if (flags & V_RDDIR_ENTFLAGS) {
2377                         /*
2378                          * Add extended flag entry:
2379                          */
2380                         eodp->ed_ino = objnum;
2381                         eodp->ed_reclen = reclen;
2382                         /* NOTE: ed_off is the offset for the *next* entry */
2383                         next = &(eodp->ed_off);
2384                         eodp->ed_eflags = zap.za_normalization_conflict ?
2385                             ED_CASE_CONFLICT : 0;
2386                         (void) strncpy(eodp->ed_name, zap.za_name,
2387                             EDIRENT_NAMELEN(reclen));
2388                         eodp = (edirent_t *)((intptr_t)eodp + reclen);
2389                 } else {
2390                         /*
2391                          * Add normal entry:
2392                          */
2393                         odp->d_ino = objnum;
2394                         odp->d_reclen = reclen;
2395                         /* NOTE: d_off is the offset for the *next* entry */
2396                         next = &(odp->d_off);
2397                         (void) strncpy(odp->d_name, zap.za_name,
2398                             DIRENT64_NAMELEN(reclen));
2399                         odp = (dirent64_t *)((intptr_t)odp + reclen);
2400                 }
2401                 outcount += reclen;
2402 
2403                 ASSERT(outcount <= bufsize);
2404 
2405                 /* Prefetch znode */
2406                 if (prefetch)
2407                         dmu_prefetch(os, objnum, 0, 0, 0,
2408                             ZIO_PRIORITY_SYNC_READ);
2409 
2410         skip_entry:
2411                 /*
2412                  * Move to the next entry, fill in the previous offset.
2413                  */
2414                 if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) {
2415                         zap_cursor_advance(&zc);
2416                         offset = zap_cursor_serialize(&zc);
2417                 } else {
2418                         offset += 1;
2419                 }
2420                 if (next)
2421                         *next = offset;
2422         }
2423         zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */
2424 
2425         if (uio->uio_segflg == UIO_SYSSPACE && uio->uio_iovcnt == 1) {
2426                 iovp->iov_base += outcount;
2427                 iovp->iov_len -= outcount;
2428                 uio->uio_resid -= outcount;
2429         } else if (error = uiomove(outbuf, (long)outcount, UIO_READ, uio)) {
2430                 /*
2431                  * Reset the pointer.
2432                  */
2433                 offset = uio->uio_loffset;
2434         }
2435 
2436 update:
2437         zap_cursor_fini(&zc);
2438         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
2439                 kmem_free(outbuf, bufsize);
2440 
2441         if (error == ENOENT)
2442                 error = 0;
2443 
2444         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
2445 
2446         uio->uio_loffset = offset;
2447         ZFS_EXIT(zfsvfs);
2448         return (error);
2449 }
2450 
2451 ulong_t zfs_fsync_sync_cnt = 4;
2452 
2453 static int
2454 zfs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
2455 {
2456         znode_t *zp = VTOZ(vp);
2457         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2458 
2459         /*
2460          * Regardless of whether this is required for standards conformance,
2461          * this is the logical behavior when fsync() is called on a file with
2462          * dirty pages.  We use B_ASYNC since the ZIL transactions are already
2463          * going to be pushed out as part of the zil_commit().
2464          */
2465         if (vn_has_cached_data(vp) && !(syncflag & FNODSYNC) &&
2466             (vp->v_type == VREG) && !(IS_SWAPVP(vp)))
2467                 (void) VOP_PUTPAGE(vp, (offset_t)0, (size_t)0, B_ASYNC, cr, ct);
2468 
2469         (void) tsd_set(zfs_fsyncer_key, (void *)zfs_fsync_sync_cnt);
2470 
2471         if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) {
2472                 ZFS_ENTER(zfsvfs);
2473                 ZFS_VERIFY_ZP(zp);
2474                 zil_commit(zfsvfs->z_log, zp->z_id);
2475                 ZFS_EXIT(zfsvfs);
2476         }
2477         return (0);
2478 }
2479 
2480 
2481 /*
2482  * Get the requested file attributes and place them in the provided
2483  * vattr structure.
2484  *
2485  *      IN:     vp      - vnode of file.
2486  *              vap     - va_mask identifies requested attributes.
2487  *                        If AT_XVATTR set, then optional attrs are requested
2488  *              flags   - ATTR_NOACLCHECK (CIFS server context)
2489  *              cr      - credentials of caller.
2490  *              ct      - caller context
2491  *
2492  *      OUT:    vap     - attribute values.
2493  *
2494  *      RETURN: 0 (always succeeds).
2495  */
2496 /* ARGSUSED */
2497 static int
2498 zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2499     caller_context_t *ct)
2500 {
2501         znode_t *zp = VTOZ(vp);
2502         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2503         int     error = 0;
2504         uint64_t links;
2505         uint64_t mtime[2], ctime[2];
2506         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
2507         xoptattr_t *xoap = NULL;
2508         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2509         sa_bulk_attr_t bulk[2];
2510         int count = 0;
2511 
2512         ZFS_ENTER(zfsvfs);
2513         ZFS_VERIFY_ZP(zp);
2514 
2515         zfs_fuid_map_ids(zp, cr, &vap->va_uid, &vap->va_gid);
2516 
2517         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
2518         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
2519 
2520         if ((error = sa_bulk_lookup(zp->z_sa_hdl, bulk, count)) != 0) {
2521                 ZFS_EXIT(zfsvfs);
2522                 return (error);
2523         }
2524 
2525         /*
2526          * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES.
2527          * Also, if we are the owner don't bother, since owner should
2528          * always be allowed to read basic attributes of file.
2529          */
2530         if (!(zp->z_pflags & ZFS_ACL_TRIVIAL) &&
2531             (vap->va_uid != crgetuid(cr))) {
2532                 if (error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, 0,
2533                     skipaclchk, cr)) {
2534                         ZFS_EXIT(zfsvfs);
2535                         return (error);
2536                 }
2537         }
2538 
2539         /*
2540          * Return all attributes.  It's cheaper to provide the answer
2541          * than to determine whether we were asked the question.
2542          */
2543 
2544         mutex_enter(&zp->z_lock);
2545         vap->va_type = vp->v_type;
2546         vap->va_mode = zp->z_mode & MODEMASK;
2547         vap->va_fsid = zp->z_zfsvfs->z_vfs->vfs_dev;
2548         vap->va_nodeid = zp->z_id;
2549         if ((vp->v_flag & VROOT) && zfs_show_ctldir(zp))
2550                 links = zp->z_links + 1;
2551         else
2552                 links = zp->z_links;
2553         vap->va_nlink = MIN(links, UINT32_MAX);      /* nlink_t limit! */
2554         vap->va_size = zp->z_size;
2555         vap->va_rdev = vp->v_rdev;
2556         vap->va_seq = zp->z_seq;
2557 
2558         /*
2559          * Add in any requested optional attributes and the create time.
2560          * Also set the corresponding bits in the returned attribute bitmap.
2561          */
2562         if ((xoap = xva_getxoptattr(xvap)) != NULL && zfsvfs->z_use_fuids) {
2563                 if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
2564                         xoap->xoa_archive =
2565                             ((zp->z_pflags & ZFS_ARCHIVE) != 0);
2566                         XVA_SET_RTN(xvap, XAT_ARCHIVE);
2567                 }
2568 
2569                 if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
2570                         xoap->xoa_readonly =
2571                             ((zp->z_pflags & ZFS_READONLY) != 0);
2572                         XVA_SET_RTN(xvap, XAT_READONLY);
2573                 }
2574 
2575                 if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
2576                         xoap->xoa_system =
2577                             ((zp->z_pflags & ZFS_SYSTEM) != 0);
2578                         XVA_SET_RTN(xvap, XAT_SYSTEM);
2579                 }
2580 
2581                 if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
2582                         xoap->xoa_hidden =
2583                             ((zp->z_pflags & ZFS_HIDDEN) != 0);
2584                         XVA_SET_RTN(xvap, XAT_HIDDEN);
2585                 }
2586 
2587                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2588                         xoap->xoa_nounlink =
2589                             ((zp->z_pflags & ZFS_NOUNLINK) != 0);
2590                         XVA_SET_RTN(xvap, XAT_NOUNLINK);
2591                 }
2592 
2593                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2594                         xoap->xoa_immutable =
2595                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0);
2596                         XVA_SET_RTN(xvap, XAT_IMMUTABLE);
2597                 }
2598 
2599                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2600                         xoap->xoa_appendonly =
2601                             ((zp->z_pflags & ZFS_APPENDONLY) != 0);
2602                         XVA_SET_RTN(xvap, XAT_APPENDONLY);
2603                 }
2604 
2605                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2606                         xoap->xoa_nodump =
2607                             ((zp->z_pflags & ZFS_NODUMP) != 0);
2608                         XVA_SET_RTN(xvap, XAT_NODUMP);
2609                 }
2610 
2611                 if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
2612                         xoap->xoa_opaque =
2613                             ((zp->z_pflags & ZFS_OPAQUE) != 0);
2614                         XVA_SET_RTN(xvap, XAT_OPAQUE);
2615                 }
2616 
2617                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2618                         xoap->xoa_av_quarantined =
2619                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0);
2620                         XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
2621                 }
2622 
2623                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2624                         xoap->xoa_av_modified =
2625                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0);
2626                         XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
2627                 }
2628 
2629                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) &&
2630                     vp->v_type == VREG) {
2631                         zfs_sa_get_scanstamp(zp, xvap);
2632                 }
2633 
2634                 if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
2635                         uint64_t times[2];
2636 
2637                         (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
2638                             times, sizeof (times));
2639                         ZFS_TIME_DECODE(&xoap->xoa_createtime, times);
2640                         XVA_SET_RTN(xvap, XAT_CREATETIME);
2641                 }
2642 
2643                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
2644                         xoap->xoa_reparse = ((zp->z_pflags & ZFS_REPARSE) != 0);
2645                         XVA_SET_RTN(xvap, XAT_REPARSE);
2646                 }
2647                 if (XVA_ISSET_REQ(xvap, XAT_GEN)) {
2648                         xoap->xoa_generation = zp->z_gen;
2649                         XVA_SET_RTN(xvap, XAT_GEN);
2650                 }
2651 
2652                 if (XVA_ISSET_REQ(xvap, XAT_OFFLINE)) {
2653                         xoap->xoa_offline =
2654                             ((zp->z_pflags & ZFS_OFFLINE) != 0);
2655                         XVA_SET_RTN(xvap, XAT_OFFLINE);
2656                 }
2657 
2658                 if (XVA_ISSET_REQ(xvap, XAT_SPARSE)) {
2659                         xoap->xoa_sparse =
2660                             ((zp->z_pflags & ZFS_SPARSE) != 0);
2661                         XVA_SET_RTN(xvap, XAT_SPARSE);
2662                 }
2663         }
2664 
2665         ZFS_TIME_DECODE(&vap->va_atime, zp->z_atime);
2666         ZFS_TIME_DECODE(&vap->va_mtime, mtime);
2667         ZFS_TIME_DECODE(&vap->va_ctime, ctime);
2668 
2669         mutex_exit(&zp->z_lock);
2670 
2671         sa_object_size(zp->z_sa_hdl, &vap->va_blksize, &vap->va_nblocks);
2672 
2673         if (zp->z_blksz == 0) {
2674                 /*
2675                  * Block size hasn't been set; suggest maximal I/O transfers.
2676                  */
2677                 vap->va_blksize = zfsvfs->z_max_blksz;
2678         }
2679 
2680         ZFS_EXIT(zfsvfs);
2681         return (0);
2682 }
2683 
2684 /*
2685  * Set the file attributes to the values contained in the
2686  * vattr structure.
2687  *
2688  *      IN:     vp      - vnode of file to be modified.
2689  *              vap     - new attribute values.
2690  *                        If AT_XVATTR set, then optional attrs are being set
2691  *              flags   - ATTR_UTIME set if non-default time values provided.
2692  *                      - ATTR_NOACLCHECK (CIFS context only).
2693  *              cr      - credentials of caller.
2694  *              ct      - caller context
2695  *
2696  *      RETURN: 0 on success, error code on failure.
2697  *
2698  * Timestamps:
2699  *      vp - ctime updated, mtime updated if size changed.
2700  */
2701 /* ARGSUSED */
2702 static int
2703 zfs_setattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2704     caller_context_t *ct)
2705 {
2706         znode_t         *zp = VTOZ(vp);
2707         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
2708         zilog_t         *zilog;
2709         dmu_tx_t        *tx;
2710         vattr_t         oldva;
2711         xvattr_t        tmpxvattr;
2712         uint_t          mask = vap->va_mask;
2713         uint_t          saved_mask = 0;
2714         int             trim_mask = 0;
2715         uint64_t        new_mode;
2716         uint64_t        new_uid, new_gid;
2717         uint64_t        xattr_obj;
2718         uint64_t        mtime[2], ctime[2];
2719         znode_t         *attrzp;
2720         int             need_policy = FALSE;
2721         int             err, err2;
2722         zfs_fuid_info_t *fuidp = NULL;
2723         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
2724         xoptattr_t      *xoap;
2725         zfs_acl_t       *aclp;
2726         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2727         boolean_t       fuid_dirtied = B_FALSE;
2728         sa_bulk_attr_t  bulk[7], xattr_bulk[7];
2729         int             count = 0, xattr_count = 0;
2730 
2731         if (mask == 0)
2732                 return (0);
2733 
2734         if (mask & AT_NOSET)
2735                 return (SET_ERROR(EINVAL));
2736 
2737         ZFS_ENTER(zfsvfs);
2738         ZFS_VERIFY_ZP(zp);
2739 
2740         zilog = zfsvfs->z_log;
2741 
2742         /*
2743          * Make sure that if we have ephemeral uid/gid or xvattr specified
2744          * that file system is at proper version level
2745          */
2746 
2747         if (zfsvfs->z_use_fuids == B_FALSE &&
2748             (((mask & AT_UID) && IS_EPHEMERAL(vap->va_uid)) ||
2749             ((mask & AT_GID) && IS_EPHEMERAL(vap->va_gid)) ||
2750             (mask & AT_XVATTR))) {
2751                 ZFS_EXIT(zfsvfs);
2752                 return (SET_ERROR(EINVAL));
2753         }
2754 
2755         if (mask & AT_SIZE && vp->v_type == VDIR) {
2756                 ZFS_EXIT(zfsvfs);
2757                 return (SET_ERROR(EISDIR));
2758         }
2759 
2760         if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) {
2761                 ZFS_EXIT(zfsvfs);
2762                 return (SET_ERROR(EINVAL));
2763         }
2764 
2765         /*
2766          * If this is an xvattr_t, then get a pointer to the structure of
2767          * optional attributes.  If this is NULL, then we have a vattr_t.
2768          */
2769         xoap = xva_getxoptattr(xvap);
2770 
2771         xva_init(&tmpxvattr);
2772 
2773         /*
2774          * Immutable files can only alter immutable bit and atime
2775          */
2776         if ((zp->z_pflags & ZFS_IMMUTABLE) &&
2777             ((mask & (AT_SIZE|AT_UID|AT_GID|AT_MTIME|AT_MODE)) ||
2778             ((mask & AT_XVATTR) && XVA_ISSET_REQ(xvap, XAT_CREATETIME)))) {
2779                 ZFS_EXIT(zfsvfs);
2780                 return (SET_ERROR(EPERM));
2781         }
2782 
2783         if ((mask & AT_SIZE) && (zp->z_pflags & ZFS_READONLY)) {
2784                 ZFS_EXIT(zfsvfs);
2785                 return (SET_ERROR(EPERM));
2786         }
2787 
2788         /*
2789          * Verify timestamps doesn't overflow 32 bits.
2790          * ZFS can handle large timestamps, but 32bit syscalls can't
2791          * handle times greater than 2039.  This check should be removed
2792          * once large timestamps are fully supported.
2793          */
2794         if (mask & (AT_ATIME | AT_MTIME)) {
2795                 if (((mask & AT_ATIME) && TIMESPEC_OVERFLOW(&vap->va_atime)) ||
2796                     ((mask & AT_MTIME) && TIMESPEC_OVERFLOW(&vap->va_mtime))) {
2797                         ZFS_EXIT(zfsvfs);
2798                         return (SET_ERROR(EOVERFLOW));
2799                 }
2800         }
2801 
2802 top:
2803         attrzp = NULL;
2804         aclp = NULL;
2805 
2806         /* Can this be moved to before the top label? */
2807         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
2808                 ZFS_EXIT(zfsvfs);
2809                 return (SET_ERROR(EROFS));
2810         }
2811 
2812         /*
2813          * First validate permissions
2814          */
2815 
2816         if (mask & AT_SIZE) {
2817                 err = zfs_zaccess(zp, ACE_WRITE_DATA, 0, skipaclchk, cr);
2818                 if (err) {
2819                         ZFS_EXIT(zfsvfs);
2820                         return (err);
2821                 }
2822                 /*
2823                  * XXX - Note, we are not providing any open
2824                  * mode flags here (like FNDELAY), so we may
2825                  * block if there are locks present... this
2826                  * should be addressed in openat().
2827                  */
2828                 /* XXX - would it be OK to generate a log record here? */
2829                 err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE);
2830                 if (err) {
2831                         ZFS_EXIT(zfsvfs);
2832                         return (err);
2833                 }
2834 
2835                 if (vap->va_size == 0)
2836                         vnevent_truncate(ZTOV(zp), ct);
2837         }
2838 
2839         if (mask & (AT_ATIME|AT_MTIME) ||
2840             ((mask & AT_XVATTR) && (XVA_ISSET_REQ(xvap, XAT_HIDDEN) ||
2841             XVA_ISSET_REQ(xvap, XAT_READONLY) ||
2842             XVA_ISSET_REQ(xvap, XAT_ARCHIVE) ||
2843             XVA_ISSET_REQ(xvap, XAT_OFFLINE) ||
2844             XVA_ISSET_REQ(xvap, XAT_SPARSE) ||
2845             XVA_ISSET_REQ(xvap, XAT_CREATETIME) ||
2846             XVA_ISSET_REQ(xvap, XAT_SYSTEM)))) {
2847                 need_policy = zfs_zaccess(zp, ACE_WRITE_ATTRIBUTES, 0,
2848                     skipaclchk, cr);
2849         }
2850 
2851         if (mask & (AT_UID|AT_GID)) {
2852                 int     idmask = (mask & (AT_UID|AT_GID));
2853                 int     take_owner;
2854                 int     take_group;
2855 
2856                 /*
2857                  * NOTE: even if a new mode is being set,
2858                  * we may clear S_ISUID/S_ISGID bits.
2859                  */
2860 
2861                 if (!(mask & AT_MODE))
2862                         vap->va_mode = zp->z_mode;
2863 
2864                 /*
2865                  * Take ownership or chgrp to group we are a member of
2866                  */
2867 
2868                 take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr));
2869                 take_group = (mask & AT_GID) &&
2870                     zfs_groupmember(zfsvfs, vap->va_gid, cr);
2871 
2872                 /*
2873                  * If both AT_UID and AT_GID are set then take_owner and
2874                  * take_group must both be set in order to allow taking
2875                  * ownership.
2876                  *
2877                  * Otherwise, send the check through secpolicy_vnode_setattr()
2878                  *
2879                  */
2880 
2881                 if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) ||
2882                     ((idmask == AT_UID) && take_owner) ||
2883                     ((idmask == AT_GID) && take_group)) {
2884                         if (zfs_zaccess(zp, ACE_WRITE_OWNER, 0,
2885                             skipaclchk, cr) == 0) {
2886                                 /*
2887                                  * Remove setuid/setgid for non-privileged users
2888                                  */
2889                                 secpolicy_setid_clear(vap, cr);
2890                                 trim_mask = (mask & (AT_UID|AT_GID));
2891                         } else {
2892                                 need_policy =  TRUE;
2893                         }
2894                 } else {
2895                         need_policy =  TRUE;
2896                 }
2897         }
2898 
2899         mutex_enter(&zp->z_lock);
2900         oldva.va_mode = zp->z_mode;
2901         zfs_fuid_map_ids(zp, cr, &oldva.va_uid, &oldva.va_gid);
2902         if (mask & AT_XVATTR) {
2903                 /*
2904                  * Update xvattr mask to include only those attributes
2905                  * that are actually changing.
2906                  *
2907                  * the bits will be restored prior to actually setting
2908                  * the attributes so the caller thinks they were set.
2909                  */
2910                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2911                         if (xoap->xoa_appendonly !=
2912                             ((zp->z_pflags & ZFS_APPENDONLY) != 0)) {
2913                                 need_policy = TRUE;
2914                         } else {
2915                                 XVA_CLR_REQ(xvap, XAT_APPENDONLY);
2916                                 XVA_SET_REQ(&tmpxvattr, XAT_APPENDONLY);
2917                         }
2918                 }
2919 
2920                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2921                         if (xoap->xoa_nounlink !=
2922                             ((zp->z_pflags & ZFS_NOUNLINK) != 0)) {
2923                                 need_policy = TRUE;
2924                         } else {
2925                                 XVA_CLR_REQ(xvap, XAT_NOUNLINK);
2926                                 XVA_SET_REQ(&tmpxvattr, XAT_NOUNLINK);
2927                         }
2928                 }
2929 
2930                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2931                         if (xoap->xoa_immutable !=
2932                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0)) {
2933                                 need_policy = TRUE;
2934                         } else {
2935                                 XVA_CLR_REQ(xvap, XAT_IMMUTABLE);
2936                                 XVA_SET_REQ(&tmpxvattr, XAT_IMMUTABLE);
2937                         }
2938                 }
2939 
2940                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2941                         if (xoap->xoa_nodump !=
2942                             ((zp->z_pflags & ZFS_NODUMP) != 0)) {
2943                                 need_policy = TRUE;
2944                         } else {
2945                                 XVA_CLR_REQ(xvap, XAT_NODUMP);
2946                                 XVA_SET_REQ(&tmpxvattr, XAT_NODUMP);
2947                         }
2948                 }
2949 
2950                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2951                         if (xoap->xoa_av_modified !=
2952                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0)) {
2953                                 need_policy = TRUE;
2954                         } else {
2955                                 XVA_CLR_REQ(xvap, XAT_AV_MODIFIED);
2956                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_MODIFIED);
2957                         }
2958                 }
2959 
2960                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2961                         if ((vp->v_type != VREG &&
2962                             xoap->xoa_av_quarantined) ||
2963                             xoap->xoa_av_quarantined !=
2964                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0)) {
2965                                 need_policy = TRUE;
2966                         } else {
2967                                 XVA_CLR_REQ(xvap, XAT_AV_QUARANTINED);
2968                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_QUARANTINED);
2969                         }
2970                 }
2971 
2972                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
2973                         mutex_exit(&zp->z_lock);
2974                         ZFS_EXIT(zfsvfs);
2975                         return (SET_ERROR(EPERM));
2976                 }
2977 
2978                 if (need_policy == FALSE &&
2979                     (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) ||
2980                     XVA_ISSET_REQ(xvap, XAT_OPAQUE))) {
2981                         need_policy = TRUE;
2982                 }
2983         }
2984 
2985         mutex_exit(&zp->z_lock);
2986 
2987         if (mask & AT_MODE) {
2988                 if (zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr) == 0) {
2989                         err = secpolicy_setid_setsticky_clear(vp, vap,
2990                             &oldva, cr);
2991                         if (err) {
2992                                 ZFS_EXIT(zfsvfs);
2993                                 return (err);
2994                         }
2995                         trim_mask |= AT_MODE;
2996                 } else {
2997                         need_policy = TRUE;
2998                 }
2999         }
3000 
3001         if (need_policy) {
3002                 /*
3003                  * If trim_mask is set then take ownership
3004                  * has been granted or write_acl is present and user
3005                  * has the ability to modify mode.  In that case remove
3006                  * UID|GID and or MODE from mask so that
3007                  * secpolicy_vnode_setattr() doesn't revoke it.
3008                  */
3009 
3010                 if (trim_mask) {
3011                         saved_mask = vap->va_mask;
3012                         vap->va_mask &= ~trim_mask;
3013                 }
3014                 err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags,
3015                     (int (*)(void *, int, cred_t *))zfs_zaccess_unix, zp);
3016                 if (err) {
3017                         ZFS_EXIT(zfsvfs);
3018                         return (err);
3019                 }
3020 
3021                 if (trim_mask)
3022                         vap->va_mask |= saved_mask;
3023         }
3024 
3025         /*
3026          * secpolicy_vnode_setattr, or take ownership may have
3027          * changed va_mask
3028          */
3029         mask = vap->va_mask;
3030 
3031         if ((mask & (AT_UID | AT_GID))) {
3032                 err = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
3033                     &xattr_obj, sizeof (xattr_obj));
3034 
3035                 if (err == 0 && xattr_obj) {
3036                         err = zfs_zget(zp->z_zfsvfs, xattr_obj, &attrzp);
3037                         if (err)
3038                                 goto out2;
3039                 }
3040                 if (mask & AT_UID) {
3041                         new_uid = zfs_fuid_create(zfsvfs,
3042                             (uint64_t)vap->va_uid, cr, ZFS_OWNER, &fuidp);
3043                         if (new_uid != zp->z_uid &&
3044                             zfs_fuid_overquota(zfsvfs, B_FALSE, new_uid)) {
3045                                 if (attrzp)
3046                                         VN_RELE(ZTOV(attrzp));
3047                                 err = SET_ERROR(EDQUOT);
3048                                 goto out2;
3049                         }
3050                 }
3051 
3052                 if (mask & AT_GID) {
3053                         new_gid = zfs_fuid_create(zfsvfs, (uint64_t)vap->va_gid,
3054                             cr, ZFS_GROUP, &fuidp);
3055                         if (new_gid != zp->z_gid &&
3056                             zfs_fuid_overquota(zfsvfs, B_TRUE, new_gid)) {
3057                                 if (attrzp)
3058                                         VN_RELE(ZTOV(attrzp));
3059                                 err = SET_ERROR(EDQUOT);
3060                                 goto out2;
3061                         }
3062                 }
3063         }
3064         tx = dmu_tx_create(zfsvfs->z_os);
3065 
3066         if (mask & AT_MODE) {
3067                 uint64_t pmode = zp->z_mode;
3068                 uint64_t acl_obj;
3069                 new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT);
3070 
3071                 if (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_RESTRICTED &&
3072                     !(zp->z_pflags & ZFS_ACL_TRIVIAL)) {
3073                         err = SET_ERROR(EPERM);
3074                         goto out;
3075                 }
3076 
3077                 if (err = zfs_acl_chmod_setattr(zp, &aclp, new_mode))
3078                         goto out;
3079 
3080                 mutex_enter(&zp->z_lock);
3081                 if (!zp->z_is_sa && ((acl_obj = zfs_external_acl(zp)) != 0)) {
3082                         /*
3083                          * Are we upgrading ACL from old V0 format
3084                          * to V1 format?
3085                          */
3086                         if (zfsvfs->z_version >= ZPL_VERSION_FUID &&
3087                             zfs_znode_acl_version(zp) ==
3088                             ZFS_ACL_VERSION_INITIAL) {
3089                                 dmu_tx_hold_free(tx, acl_obj, 0,
3090                                     DMU_OBJECT_END);
3091                                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3092                                     0, aclp->z_acl_bytes);
3093                         } else {
3094                                 dmu_tx_hold_write(tx, acl_obj, 0,
3095                                     aclp->z_acl_bytes);
3096                         }
3097                 } else if (!zp->z_is_sa && aclp->z_acl_bytes > ZFS_ACE_SPACE) {
3098                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3099                             0, aclp->z_acl_bytes);
3100                 }
3101                 mutex_exit(&zp->z_lock);
3102                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3103         } else {
3104                 if ((mask & AT_XVATTR) &&
3105                     XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3106                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3107                 else
3108                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
3109         }
3110 
3111         if (attrzp) {
3112                 dmu_tx_hold_sa(tx, attrzp->z_sa_hdl, B_FALSE);
3113         }
3114 
3115         fuid_dirtied = zfsvfs->z_fuid_dirty;
3116         if (fuid_dirtied)
3117                 zfs_fuid_txhold(zfsvfs, tx);
3118 
3119         zfs_sa_upgrade_txholds(tx, zp);
3120 
3121         err = dmu_tx_assign(tx, TXG_WAIT);
3122         if (err)
3123                 goto out;
3124 
3125         count = 0;
3126         /*
3127          * Set each attribute requested.
3128          * We group settings according to the locks they need to acquire.
3129          *
3130          * Note: you cannot set ctime directly, although it will be
3131          * updated as a side-effect of calling this function.
3132          */
3133 
3134 
3135         if (mask & (AT_UID|AT_GID|AT_MODE))
3136                 mutex_enter(&zp->z_acl_lock);
3137         mutex_enter(&zp->z_lock);
3138 
3139         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
3140             &zp->z_pflags, sizeof (zp->z_pflags));
3141 
3142         if (attrzp) {
3143                 if (mask & (AT_UID|AT_GID|AT_MODE))
3144                         mutex_enter(&attrzp->z_acl_lock);
3145                 mutex_enter(&attrzp->z_lock);
3146                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3147                     SA_ZPL_FLAGS(zfsvfs), NULL, &attrzp->z_pflags,
3148                     sizeof (attrzp->z_pflags));
3149         }
3150 
3151         if (mask & (AT_UID|AT_GID)) {
3152 
3153                 if (mask & AT_UID) {
3154                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
3155                             &new_uid, sizeof (new_uid));
3156                         zp->z_uid = new_uid;
3157                         if (attrzp) {
3158                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3159                                     SA_ZPL_UID(zfsvfs), NULL, &new_uid,
3160                                     sizeof (new_uid));
3161                                 attrzp->z_uid = new_uid;
3162                         }
3163                 }
3164 
3165                 if (mask & AT_GID) {
3166                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs),
3167                             NULL, &new_gid, sizeof (new_gid));
3168                         zp->z_gid = new_gid;
3169                         if (attrzp) {
3170                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3171                                     SA_ZPL_GID(zfsvfs), NULL, &new_gid,
3172                                     sizeof (new_gid));
3173                                 attrzp->z_gid = new_gid;
3174                         }
3175                 }
3176                 if (!(mask & AT_MODE)) {
3177                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs),
3178                             NULL, &new_mode, sizeof (new_mode));
3179                         new_mode = zp->z_mode;
3180                 }
3181                 err = zfs_acl_chown_setattr(zp);
3182                 ASSERT(err == 0);
3183                 if (attrzp) {
3184                         err = zfs_acl_chown_setattr(attrzp);
3185                         ASSERT(err == 0);
3186                 }
3187         }
3188 
3189         if (mask & AT_MODE) {
3190                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
3191                     &new_mode, sizeof (new_mode));
3192                 zp->z_mode = new_mode;
3193                 ASSERT3U((uintptr_t)aclp, !=, NULL);
3194                 err = zfs_aclset_common(zp, aclp, cr, tx);
3195                 ASSERT0(err);
3196                 if (zp->z_acl_cached)
3197                         zfs_acl_free(zp->z_acl_cached);
3198                 zp->z_acl_cached = aclp;
3199                 aclp = NULL;
3200         }
3201 
3202 
3203         if (mask & AT_ATIME) {
3204                 ZFS_TIME_ENCODE(&vap->va_atime, zp->z_atime);
3205                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ATIME(zfsvfs), NULL,
3206                     &zp->z_atime, sizeof (zp->z_atime));
3207         }
3208 
3209         if (mask & AT_MTIME) {
3210                 ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
3211                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
3212                     mtime, sizeof (mtime));
3213         }
3214 
3215         /* XXX - shouldn't this be done *before* the ATIME/MTIME checks? */
3216         if (mask & AT_SIZE && !(mask & AT_MTIME)) {
3217                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
3218                     NULL, mtime, sizeof (mtime));
3219                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3220                     &ctime, sizeof (ctime));
3221                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
3222                     B_TRUE);
3223         } else if (mask != 0) {
3224                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3225                     &ctime, sizeof (ctime));
3226                 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
3227                     B_TRUE);
3228                 if (attrzp) {
3229                         SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3230                             SA_ZPL_CTIME(zfsvfs), NULL,
3231                             &ctime, sizeof (ctime));
3232                         zfs_tstamp_update_setup(attrzp, STATE_CHANGED,
3233                             mtime, ctime, B_TRUE);
3234                 }
3235         }
3236         /*
3237          * Do this after setting timestamps to prevent timestamp
3238          * update from toggling bit
3239          */
3240 
3241         if (xoap && (mask & AT_XVATTR)) {
3242 
3243                 /*
3244                  * restore trimmed off masks
3245                  * so that return masks can be set for caller.
3246                  */
3247 
3248                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_APPENDONLY)) {
3249                         XVA_SET_REQ(xvap, XAT_APPENDONLY);
3250                 }
3251                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NOUNLINK)) {
3252                         XVA_SET_REQ(xvap, XAT_NOUNLINK);
3253                 }
3254                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_IMMUTABLE)) {
3255                         XVA_SET_REQ(xvap, XAT_IMMUTABLE);
3256                 }
3257                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NODUMP)) {
3258                         XVA_SET_REQ(xvap, XAT_NODUMP);
3259                 }
3260                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_MODIFIED)) {
3261                         XVA_SET_REQ(xvap, XAT_AV_MODIFIED);
3262                 }
3263                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_QUARANTINED)) {
3264                         XVA_SET_REQ(xvap, XAT_AV_QUARANTINED);
3265                 }
3266 
3267                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3268                         ASSERT(vp->v_type == VREG);
3269 
3270                 zfs_xvattr_set(zp, xvap, tx);
3271         }
3272 
3273         if (fuid_dirtied)
3274                 zfs_fuid_sync(zfsvfs, tx);
3275 
3276         if (mask != 0)
3277                 zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);
3278 
3279         mutex_exit(&zp->z_lock);
3280         if (mask & (AT_UID|AT_GID|AT_MODE))
3281                 mutex_exit(&zp->z_acl_lock);
3282 
3283         if (attrzp) {
3284                 if (mask & (AT_UID|AT_GID|AT_MODE))
3285                         mutex_exit(&attrzp->z_acl_lock);
3286                 mutex_exit(&attrzp->z_lock);
3287         }
3288 out:
3289         if (err == 0 && attrzp) {
3290                 err2 = sa_bulk_update(attrzp->z_sa_hdl, xattr_bulk,
3291                     xattr_count, tx);
3292                 ASSERT(err2 == 0);
3293         }
3294 
3295         if (attrzp)
3296                 VN_RELE(ZTOV(attrzp));
3297 
3298         if (aclp)
3299                 zfs_acl_free(aclp);
3300 
3301         if (fuidp) {
3302                 zfs_fuid_info_free(fuidp);
3303                 fuidp = NULL;
3304         }
3305 
3306         if (err) {
3307                 dmu_tx_abort(tx);
3308                 if (err == ERESTART)
3309                         goto top;
3310         } else {
3311                 err2 = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
3312                 dmu_tx_commit(tx);
3313         }
3314 
3315 out2:
3316         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3317                 zil_commit(zilog, 0);
3318 
3319         ZFS_EXIT(zfsvfs);
3320         return (err);
3321 }
3322 
3323 typedef struct zfs_zlock {
3324         krwlock_t       *zl_rwlock;     /* lock we acquired */
3325         znode_t         *zl_znode;      /* znode we held */
3326         struct zfs_zlock *zl_next;      /* next in list */
3327 } zfs_zlock_t;
3328 
3329 /*
3330  * Drop locks and release vnodes that were held by zfs_rename_lock().
3331  */
3332 static void
3333 zfs_rename_unlock(zfs_zlock_t **zlpp)
3334 {
3335         zfs_zlock_t *zl;
3336 
3337         while ((zl = *zlpp) != NULL) {
3338                 if (zl->zl_znode != NULL)
3339                         VN_RELE(ZTOV(zl->zl_znode));
3340                 rw_exit(zl->zl_rwlock);
3341                 *zlpp = zl->zl_next;
3342                 kmem_free(zl, sizeof (*zl));
3343         }
3344 }
3345 
3346 /*
3347  * Search back through the directory tree, using the ".." entries.
3348  * Lock each directory in the chain to prevent concurrent renames.
3349  * Fail any attempt to move a directory into one of its own descendants.
3350  * XXX - z_parent_lock can overlap with map or grow locks
3351  */
3352 static int
3353 zfs_rename_lock(znode_t *szp, znode_t *tdzp, znode_t *sdzp, zfs_zlock_t **zlpp)
3354 {
3355         zfs_zlock_t     *zl;
3356         znode_t         *zp = tdzp;
3357         uint64_t        rootid = zp->z_zfsvfs->z_root;
3358         uint64_t        oidp = zp->z_id;
3359         krwlock_t       *rwlp = &szp->z_parent_lock;
3360         krw_t           rw = RW_WRITER;
3361 
3362         /*
3363          * First pass write-locks szp and compares to zp->z_id.
3364          * Later passes read-lock zp and compare to zp->z_parent.
3365          */
3366         do {
3367                 if (!rw_tryenter(rwlp, rw)) {
3368                         /*
3369                          * Another thread is renaming in this path.
3370                          * Note that if we are a WRITER, we don't have any
3371                          * parent_locks held yet.
3372                          */
3373                         if (rw == RW_READER && zp->z_id > szp->z_id) {
3374                                 /*
3375                                  * Drop our locks and restart
3376                                  */
3377                                 zfs_rename_unlock(&zl);
3378                                 *zlpp = NULL;
3379                                 zp = tdzp;
3380                                 oidp = zp->z_id;
3381                                 rwlp = &szp->z_parent_lock;
3382                                 rw = RW_WRITER;
3383                                 continue;
3384                         } else {
3385                                 /*
3386                                  * Wait for other thread to drop its locks
3387                                  */
3388                                 rw_enter(rwlp, rw);
3389                         }
3390                 }
3391 
3392                 zl = kmem_alloc(sizeof (*zl), KM_SLEEP);
3393                 zl->zl_rwlock = rwlp;
3394                 zl->zl_znode = NULL;
3395                 zl->zl_next = *zlpp;
3396                 *zlpp = zl;
3397 
3398                 if (oidp == szp->z_id)               /* We're a descendant of szp */
3399                         return (SET_ERROR(EINVAL));
3400 
3401                 if (oidp == rootid)             /* We've hit the top */
3402                         return (0);
3403 
3404                 if (rw == RW_READER) {          /* i.e. not the first pass */
3405                         int error = zfs_zget(zp->z_zfsvfs, oidp, &zp);
3406                         if (error)
3407                                 return (error);
3408                         zl->zl_znode = zp;
3409                 }
3410                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zp->z_zfsvfs),
3411                     &oidp, sizeof (oidp));
3412                 rwlp = &zp->z_parent_lock;
3413                 rw = RW_READER;
3414 
3415         } while (zp->z_id != sdzp->z_id);
3416 
3417         return (0);
3418 }
3419 
3420 /*
3421  * Move an entry from the provided source directory to the target
3422  * directory.  Change the entry name as indicated.
3423  *
3424  *      IN:     sdvp    - Source directory containing the "old entry".
3425  *              snm     - Old entry name.
3426  *              tdvp    - Target directory to contain the "new entry".
3427  *              tnm     - New entry name.
3428  *              cr      - credentials of caller.
3429  *              ct      - caller context
3430  *              flags   - case flags
3431  *
3432  *      RETURN: 0 on success, error code on failure.
3433  *
3434  * Timestamps:
3435  *      sdvp,tdvp - ctime|mtime updated
3436  */
3437 /*ARGSUSED*/
3438 static int
3439 zfs_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
3440     caller_context_t *ct, int flags)
3441 {
3442         znode_t         *tdzp, *szp, *tzp;
3443         znode_t         *sdzp = VTOZ(sdvp);
3444         zfsvfs_t        *zfsvfs = sdzp->z_zfsvfs;
3445         zilog_t         *zilog;
3446         vnode_t         *realvp;
3447         zfs_dirlock_t   *sdl, *tdl;
3448         dmu_tx_t        *tx;
3449         zfs_zlock_t     *zl;
3450         int             cmp, serr, terr;
3451         int             error = 0;
3452         int             zflg = 0;
3453         boolean_t       waited = B_FALSE;
3454 
3455         ZFS_ENTER(zfsvfs);
3456         ZFS_VERIFY_ZP(sdzp);
3457         zilog = zfsvfs->z_log;
3458 
3459         /*
3460          * Make sure we have the real vp for the target directory.
3461          */
3462         if (VOP_REALVP(tdvp, &realvp, ct) == 0)
3463                 tdvp = realvp;
3464 
3465         tdzp = VTOZ(tdvp);
3466         ZFS_VERIFY_ZP(tdzp);
3467 
3468         /*
3469          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
3470          * ctldir appear to have the same v_vfsp.
3471          */
3472         if (tdzp->z_zfsvfs != zfsvfs || zfsctl_is_node(tdvp)) {
3473                 ZFS_EXIT(zfsvfs);
3474                 return (SET_ERROR(EXDEV));
3475         }
3476 
3477         if (zfsvfs->z_utf8 && u8_validate(tnm,
3478             strlen(tnm), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3479                 ZFS_EXIT(zfsvfs);
3480                 return (SET_ERROR(EILSEQ));
3481         }
3482 
3483         if (flags & FIGNORECASE)
3484                 zflg |= ZCILOOK;
3485 
3486 top:
3487         szp = NULL;
3488         tzp = NULL;
3489         zl = NULL;
3490 
3491         /*
3492          * This is to prevent the creation of links into attribute space
3493          * by renaming a linked file into/outof an attribute directory.
3494          * See the comment in zfs_link() for why this is considered bad.
3495          */
3496         if ((tdzp->z_pflags & ZFS_XATTR) != (sdzp->z_pflags & ZFS_XATTR)) {
3497                 ZFS_EXIT(zfsvfs);
3498                 return (SET_ERROR(EINVAL));
3499         }
3500 
3501         /*
3502          * Lock source and target directory entries.  To prevent deadlock,
3503          * a lock ordering must be defined.  We lock the directory with
3504          * the smallest object id first, or if it's a tie, the one with
3505          * the lexically first name.
3506          */
3507         if (sdzp->z_id < tdzp->z_id) {
3508                 cmp = -1;
3509         } else if (sdzp->z_id > tdzp->z_id) {
3510                 cmp = 1;
3511         } else {
3512                 /*
3513                  * First compare the two name arguments without
3514                  * considering any case folding.
3515                  */
3516                 int nofold = (zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER);
3517 
3518                 cmp = u8_strcmp(snm, tnm, 0, nofold, U8_UNICODE_LATEST, &error);
3519                 ASSERT(error == 0 || !zfsvfs->z_utf8);
3520                 if (cmp == 0) {
3521                         /*
3522                          * POSIX: "If the old argument and the new argument
3523                          * both refer to links to the same existing file,
3524                          * the rename() function shall return successfully
3525                          * and perform no other action."
3526                          */
3527                         ZFS_EXIT(zfsvfs);
3528                         return (0);
3529                 }
3530                 /*
3531                  * If the file system is case-folding, then we may
3532                  * have some more checking to do.  A case-folding file
3533                  * system is either supporting mixed case sensitivity
3534                  * access or is completely case-insensitive.  Note
3535                  * that the file system is always case preserving.
3536                  *
3537                  * In mixed sensitivity mode case sensitive behavior
3538                  * is the default.  FIGNORECASE must be used to
3539                  * explicitly request case insensitive behavior.
3540                  *
3541                  * If the source and target names provided differ only
3542                  * by case (e.g., a request to rename 'tim' to 'Tim'),
3543                  * we will treat this as a special case in the
3544                  * case-insensitive mode: as long as the source name
3545                  * is an exact match, we will allow this to proceed as
3546                  * a name-change request.
3547                  */
3548                 if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
3549                     (zfsvfs->z_case == ZFS_CASE_MIXED &&
3550                     flags & FIGNORECASE)) &&
3551                     u8_strcmp(snm, tnm, 0, zfsvfs->z_norm, U8_UNICODE_LATEST,
3552                     &error) == 0) {
3553                         /*
3554                          * case preserving rename request, require exact
3555                          * name matches
3556                          */
3557                         zflg |= ZCIEXACT;
3558                         zflg &= ~ZCILOOK;
3559                 }
3560         }
3561 
3562         /*
3563          * If the source and destination directories are the same, we should
3564          * grab the z_name_lock of that directory only once.
3565          */
3566         if (sdzp == tdzp) {
3567                 zflg |= ZHAVELOCK;
3568                 rw_enter(&sdzp->z_name_lock, RW_READER);
3569         }
3570 
3571         if (cmp < 0) {
3572                 serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp,
3573                     ZEXISTS | zflg, NULL, NULL);
3574                 terr = zfs_dirent_lock(&tdl,
3575                     tdzp, tnm, &tzp, ZRENAMING | zflg, NULL, NULL);
3576         } else {
3577                 terr = zfs_dirent_lock(&tdl,
3578                     tdzp, tnm, &tzp, zflg, NULL, NULL);
3579                 serr = zfs_dirent_lock(&sdl,
3580                     sdzp, snm, &szp, ZEXISTS | ZRENAMING | zflg,
3581                     NULL, NULL);
3582         }
3583 
3584         if (serr) {
3585                 /*
3586                  * Source entry invalid or not there.
3587                  */
3588                 if (!terr) {
3589                         zfs_dirent_unlock(tdl);
3590                         if (tzp)
3591                                 VN_RELE(ZTOV(tzp));
3592                 }
3593 
3594                 if (sdzp == tdzp)
3595                         rw_exit(&sdzp->z_name_lock);
3596 
3597                 if (strcmp(snm, "..") == 0)
3598                         serr = SET_ERROR(EINVAL);
3599                 ZFS_EXIT(zfsvfs);
3600                 return (serr);
3601         }
3602         if (terr) {
3603                 zfs_dirent_unlock(sdl);
3604                 VN_RELE(ZTOV(szp));
3605 
3606                 if (sdzp == tdzp)
3607                         rw_exit(&sdzp->z_name_lock);
3608 
3609                 if (strcmp(tnm, "..") == 0)
3610                         terr = SET_ERROR(EINVAL);
3611                 ZFS_EXIT(zfsvfs);
3612                 return (terr);
3613         }
3614 
3615         /*
3616          * Must have write access at the source to remove the old entry
3617          * and write access at the target to create the new entry.
3618          * Note that if target and source are the same, this can be
3619          * done in a single check.
3620          */
3621 
3622         if (error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr))
3623                 goto out;
3624 
3625         if (ZTOV(szp)->v_type == VDIR) {
3626                 /*
3627                  * Check to make sure rename is valid.
3628                  * Can't do a move like this: /usr/a/b to /usr/a/b/c/d
3629                  */
3630                 if (error = zfs_rename_lock(szp, tdzp, sdzp, &zl))
3631                         goto out;
3632         }
3633 
3634         /*
3635          * Does target exist?
3636          */
3637         if (tzp) {
3638                 /*
3639                  * Source and target must be the same type.
3640                  */
3641                 if (ZTOV(szp)->v_type == VDIR) {
3642                         if (ZTOV(tzp)->v_type != VDIR) {
3643                                 error = SET_ERROR(ENOTDIR);
3644                                 goto out;
3645                         }
3646                 } else {
3647                         if (ZTOV(tzp)->v_type == VDIR) {
3648                                 error = SET_ERROR(EISDIR);
3649                                 goto out;
3650                         }
3651                 }
3652                 /*
3653                  * POSIX dictates that when the source and target
3654                  * entries refer to the same file object, rename
3655                  * must do nothing and exit without error.
3656                  */
3657                 if (szp->z_id == tzp->z_id) {
3658                         error = 0;
3659                         goto out;
3660                 }
3661         }
3662 
3663         vnevent_rename_src(ZTOV(szp), sdvp, snm, ct);
3664         if (tzp)
3665                 vnevent_rename_dest(ZTOV(tzp), tdvp, tnm, ct);
3666 
3667         /*
3668          * notify the target directory if it is not the same
3669          * as source directory.
3670          */
3671         if (tdvp != sdvp) {
3672                 vnevent_rename_dest_dir(tdvp, ct);
3673         }
3674 
3675         tx = dmu_tx_create(zfsvfs->z_os);
3676         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
3677         dmu_tx_hold_sa(tx, sdzp->z_sa_hdl, B_FALSE);
3678         dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm);
3679         dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm);
3680         if (sdzp != tdzp) {
3681                 dmu_tx_hold_sa(tx, tdzp->z_sa_hdl, B_FALSE);
3682                 zfs_sa_upgrade_txholds(tx, tdzp);
3683         }
3684         if (tzp) {
3685                 dmu_tx_hold_sa(tx, tzp->z_sa_hdl, B_FALSE);
3686                 zfs_sa_upgrade_txholds(tx, tzp);
3687         }
3688 
3689         zfs_sa_upgrade_txholds(tx, szp);
3690         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
3691         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
3692         if (error) {
3693                 if (zl != NULL)
3694                         zfs_rename_unlock(&zl);
3695                 zfs_dirent_unlock(sdl);
3696                 zfs_dirent_unlock(tdl);
3697 
3698                 if (sdzp == tdzp)
3699                         rw_exit(&sdzp->z_name_lock);
3700 
3701                 VN_RELE(ZTOV(szp));
3702                 if (tzp)
3703                         VN_RELE(ZTOV(tzp));
3704                 if (error == ERESTART) {
3705                         waited = B_TRUE;
3706                         dmu_tx_wait(tx);
3707                         dmu_tx_abort(tx);
3708                         goto top;
3709                 }
3710                 dmu_tx_abort(tx);
3711                 ZFS_EXIT(zfsvfs);
3712                 return (error);
3713         }
3714 
3715         if (tzp)        /* Attempt to remove the existing target */
3716                 error = zfs_link_destroy(tdl, tzp, tx, zflg, NULL);
3717 
3718         if (error == 0) {
3719                 error = zfs_link_create(tdl, szp, tx, ZRENAMING);
3720                 if (error == 0) {
3721                         szp->z_pflags |= ZFS_AV_MODIFIED;
3722 
3723                         error = sa_update(szp->z_sa_hdl, SA_ZPL_FLAGS(zfsvfs),
3724                             (void *)&szp->z_pflags, sizeof (uint64_t), tx);
3725                         ASSERT0(error);
3726 
3727                         error = zfs_link_destroy(sdl, szp, tx, ZRENAMING, NULL);
3728                         if (error == 0) {
3729                                 zfs_log_rename(zilog, tx, TX_RENAME |
3730                                     (flags & FIGNORECASE ? TX_CI : 0), sdzp,
3731                                     sdl->dl_name, tdzp, tdl->dl_name, szp);
3732 
3733                                 /*
3734                                  * Update path information for the target vnode
3735                                  */
3736                                 vn_renamepath(tdvp, ZTOV(szp), tnm,
3737                                     strlen(tnm));
3738                         } else {
3739                                 /*
3740                                  * At this point, we have successfully created
3741                                  * the target name, but have failed to remove
3742                                  * the source name.  Since the create was done
3743                                  * with the ZRENAMING flag, there are
3744                                  * complications; for one, the link count is
3745                                  * wrong.  The easiest way to deal with this
3746                                  * is to remove the newly created target, and
3747                                  * return the original error.  This must
3748                                  * succeed; fortunately, it is very unlikely to
3749                                  * fail, since we just created it.
3750                                  */
3751                                 VERIFY3U(zfs_link_destroy(tdl, szp, tx,
3752                                     ZRENAMING, NULL), ==, 0);
3753                         }
3754                 }
3755         }
3756 
3757         dmu_tx_commit(tx);
3758 out:
3759         if (zl != NULL)
3760                 zfs_rename_unlock(&zl);
3761 
3762         zfs_dirent_unlock(sdl);
3763         zfs_dirent_unlock(tdl);
3764 
3765         if (sdzp == tdzp)
3766                 rw_exit(&sdzp->z_name_lock);
3767 
3768 
3769         VN_RELE(ZTOV(szp));
3770         if (tzp)
3771                 VN_RELE(ZTOV(tzp));
3772 
3773         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3774                 zil_commit(zilog, 0);
3775 
3776         ZFS_EXIT(zfsvfs);
3777         return (error);
3778 }
3779 
3780 /*
3781  * Insert the indicated symbolic reference entry into the directory.
3782  *
3783  *      IN:     dvp     - Directory to contain new symbolic link.
3784  *              link    - Name for new symlink entry.
3785  *              vap     - Attributes of new entry.
3786  *              cr      - credentials of caller.
3787  *              ct      - caller context
3788  *              flags   - case flags
3789  *
3790  *      RETURN: 0 on success, error code on failure.
3791  *
3792  * Timestamps:
3793  *      dvp - ctime|mtime updated
3794  */
3795 /*ARGSUSED*/
3796 static int
3797 zfs_symlink(vnode_t *dvp, char *name, vattr_t *vap, char *link, cred_t *cr,
3798     caller_context_t *ct, int flags)
3799 {
3800         znode_t         *zp, *dzp = VTOZ(dvp);
3801         zfs_dirlock_t   *dl;
3802         dmu_tx_t        *tx;
3803         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
3804         zilog_t         *zilog;
3805         uint64_t        len = strlen(link);
3806         int             error;
3807         int             zflg = ZNEW;
3808         zfs_acl_ids_t   acl_ids;
3809         boolean_t       fuid_dirtied;
3810         uint64_t        txtype = TX_SYMLINK;
3811         boolean_t       waited = B_FALSE;
3812 
3813         ASSERT(vap->va_type == VLNK);
3814 
3815         ZFS_ENTER(zfsvfs);
3816         ZFS_VERIFY_ZP(dzp);
3817         zilog = zfsvfs->z_log;
3818 
3819         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
3820             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3821                 ZFS_EXIT(zfsvfs);
3822                 return (SET_ERROR(EILSEQ));
3823         }
3824         if (flags & FIGNORECASE)
3825                 zflg |= ZCILOOK;
3826 
3827         if (len > MAXPATHLEN) {
3828                 ZFS_EXIT(zfsvfs);
3829                 return (SET_ERROR(ENAMETOOLONG));
3830         }
3831 
3832         if ((error = zfs_acl_ids_create(dzp, 0,
3833             vap, cr, NULL, &acl_ids)) != 0) {
3834                 ZFS_EXIT(zfsvfs);
3835                 return (error);
3836         }
3837 top:
3838         /*
3839          * Attempt to lock directory; fail if entry already exists.
3840          */
3841         error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg, NULL, NULL);
3842         if (error) {
3843                 zfs_acl_ids_free(&acl_ids);
3844                 ZFS_EXIT(zfsvfs);
3845                 return (error);
3846         }
3847 
3848         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
3849                 zfs_acl_ids_free(&acl_ids);
3850                 zfs_dirent_unlock(dl);
3851                 ZFS_EXIT(zfsvfs);
3852                 return (error);
3853         }
3854 
3855         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
3856                 zfs_acl_ids_free(&acl_ids);
3857                 zfs_dirent_unlock(dl);
3858                 ZFS_EXIT(zfsvfs);
3859                 return (SET_ERROR(EDQUOT));
3860         }
3861         tx = dmu_tx_create(zfsvfs->z_os);
3862         fuid_dirtied = zfsvfs->z_fuid_dirty;
3863         dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len));
3864         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
3865         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
3866             ZFS_SA_BASE_ATTR_SIZE + len);
3867         dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
3868         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
3869                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
3870                     acl_ids.z_aclp->z_acl_bytes);
3871         }
3872         if (fuid_dirtied)
3873                 zfs_fuid_txhold(zfsvfs, tx);
3874         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
3875         if (error) {
3876                 zfs_dirent_unlock(dl);
3877                 if (error == ERESTART) {
3878                         waited = B_TRUE;
3879                         dmu_tx_wait(tx);
3880                         dmu_tx_abort(tx);
3881                         goto top;
3882                 }
3883                 zfs_acl_ids_free(&acl_ids);
3884                 dmu_tx_abort(tx);
3885                 ZFS_EXIT(zfsvfs);
3886                 return (error);
3887         }
3888 
3889         /*
3890          * Create a new object for the symlink.
3891          * for version 4 ZPL datsets the symlink will be an SA attribute
3892          */
3893         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
3894 
3895         if (fuid_dirtied)
3896                 zfs_fuid_sync(zfsvfs, tx);
3897 
3898         mutex_enter(&zp->z_lock);
3899         if (zp->z_is_sa)
3900                 error = sa_update(zp->z_sa_hdl, SA_ZPL_SYMLINK(zfsvfs),
3901                     link, len, tx);
3902         else
3903                 zfs_sa_symlink(zp, link, len, tx);
3904         mutex_exit(&zp->z_lock);
3905 
3906         zp->z_size = len;
3907         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
3908             &zp->z_size, sizeof (zp->z_size), tx);
3909         /*
3910          * Insert the new object into the directory.
3911          */
3912         (void) zfs_link_create(dl, zp, tx, ZNEW);
3913 
3914         if (flags & FIGNORECASE)
3915                 txtype |= TX_CI;
3916         zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
3917 
3918         zfs_acl_ids_free(&acl_ids);
3919 
3920         dmu_tx_commit(tx);
3921 
3922         zfs_dirent_unlock(dl);
3923 
3924         VN_RELE(ZTOV(zp));
3925 
3926         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3927                 zil_commit(zilog, 0);
3928 
3929         ZFS_EXIT(zfsvfs);
3930         return (error);
3931 }
3932 
3933 /*
3934  * Return, in the buffer contained in the provided uio structure,
3935  * the symbolic path referred to by vp.
3936  *
3937  *      IN:     vp      - vnode of symbolic link.
3938  *              uio     - structure to contain the link path.
3939  *              cr      - credentials of caller.
3940  *              ct      - caller context
3941  *
3942  *      OUT:    uio     - structure containing the link path.
3943  *
3944  *      RETURN: 0 on success, error code on failure.
3945  *
3946  * Timestamps:
3947  *      vp - atime updated
3948  */
3949 /* ARGSUSED */
3950 static int
3951 zfs_readlink(vnode_t *vp, uio_t *uio, cred_t *cr, caller_context_t *ct)
3952 {
3953         znode_t         *zp = VTOZ(vp);
3954         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
3955         int             error;
3956 
3957         ZFS_ENTER(zfsvfs);
3958         ZFS_VERIFY_ZP(zp);
3959 
3960         mutex_enter(&zp->z_lock);
3961         if (zp->z_is_sa)
3962                 error = sa_lookup_uio(zp->z_sa_hdl,
3963                     SA_ZPL_SYMLINK(zfsvfs), uio);
3964         else
3965                 error = zfs_sa_readlink(zp, uio);
3966         mutex_exit(&zp->z_lock);
3967 
3968         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
3969 
3970         ZFS_EXIT(zfsvfs);
3971         return (error);
3972 }
3973 
3974 /*
3975  * Insert a new entry into directory tdvp referencing svp.
3976  *
3977  *      IN:     tdvp    - Directory to contain new entry.
3978  *              svp     - vnode of new entry.
3979  *              name    - name of new entry.
3980  *              cr      - credentials of caller.
3981  *              ct      - caller context
3982  *
3983  *      RETURN: 0 on success, error code on failure.
3984  *
3985  * Timestamps:
3986  *      tdvp - ctime|mtime updated
3987  *       svp - ctime updated
3988  */
3989 /* ARGSUSED */
3990 static int
3991 zfs_link(vnode_t *tdvp, vnode_t *svp, char *name, cred_t *cr,
3992     caller_context_t *ct, int flags)
3993 {
3994         znode_t         *dzp = VTOZ(tdvp);
3995         znode_t         *tzp, *szp;
3996         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
3997         zilog_t         *zilog;
3998         zfs_dirlock_t   *dl;
3999         dmu_tx_t        *tx;
4000         vnode_t         *realvp;
4001         int             error;
4002         int             zf = ZNEW;
4003         uint64_t        parent;
4004         uid_t           owner;
4005         boolean_t       waited = B_FALSE;
4006 
4007         ASSERT(tdvp->v_type == VDIR);
4008 
4009         ZFS_ENTER(zfsvfs);
4010         ZFS_VERIFY_ZP(dzp);
4011         zilog = zfsvfs->z_log;
4012 
4013         if (VOP_REALVP(svp, &realvp, ct) == 0)
4014                 svp = realvp;
4015 
4016         /*
4017          * POSIX dictates that we return EPERM here.
4018          * Better choices include ENOTSUP or EISDIR.
4019          */
4020         if (svp->v_type == VDIR) {
4021                 ZFS_EXIT(zfsvfs);
4022                 return (SET_ERROR(EPERM));
4023         }
4024 
4025         szp = VTOZ(svp);
4026         ZFS_VERIFY_ZP(szp);
4027 
4028         /*
4029          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
4030          * ctldir appear to have the same v_vfsp.
4031          */
4032         if (szp->z_zfsvfs != zfsvfs || zfsctl_is_node(svp)) {
4033                 ZFS_EXIT(zfsvfs);
4034                 return (SET_ERROR(EXDEV));
4035         }
4036 
4037         /* Prevent links to .zfs/shares files */
4038 
4039         if ((error = sa_lookup(szp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
4040             &parent, sizeof (uint64_t))) != 0) {
4041                 ZFS_EXIT(zfsvfs);
4042                 return (error);
4043         }
4044         if (parent == zfsvfs->z_shares_dir) {
4045                 ZFS_EXIT(zfsvfs);
4046                 return (SET_ERROR(EPERM));
4047         }
4048 
4049         if (zfsvfs->z_utf8 && u8_validate(name,
4050             strlen(name), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
4051                 ZFS_EXIT(zfsvfs);
4052                 return (SET_ERROR(EILSEQ));
4053         }
4054         if (flags & FIGNORECASE)
4055                 zf |= ZCILOOK;
4056 
4057         /*
4058          * We do not support links between attributes and non-attributes
4059          * because of the potential security risk of creating links
4060          * into "normal" file space in order to circumvent restrictions
4061          * imposed in attribute space.
4062          */
4063         if ((szp->z_pflags & ZFS_XATTR) != (dzp->z_pflags & ZFS_XATTR)) {
4064                 ZFS_EXIT(zfsvfs);
4065                 return (SET_ERROR(EINVAL));
4066         }
4067 
4068 
4069         owner = zfs_fuid_map_id(zfsvfs, szp->z_uid, cr, ZFS_OWNER);
4070         if (owner != crgetuid(cr) && secpolicy_basic_link(cr) != 0) {
4071                 ZFS_EXIT(zfsvfs);
4072                 return (SET_ERROR(EPERM));
4073         }
4074 
4075         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
4076                 ZFS_EXIT(zfsvfs);
4077                 return (error);
4078         }
4079 
4080 top:
4081         /*
4082          * Attempt to lock directory; fail if entry already exists.
4083          */
4084         error = zfs_dirent_lock(&dl, dzp, name, &tzp, zf, NULL, NULL);
4085         if (error) {
4086                 ZFS_EXIT(zfsvfs);
4087                 return (error);
4088         }
4089 
4090         tx = dmu_tx_create(zfsvfs->z_os);
4091         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
4092         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
4093         zfs_sa_upgrade_txholds(tx, szp);
4094         zfs_sa_upgrade_txholds(tx, dzp);
4095         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
4096         if (error) {
4097                 zfs_dirent_unlock(dl);
4098                 if (error == ERESTART) {
4099                         waited = B_TRUE;
4100                         dmu_tx_wait(tx);
4101                         dmu_tx_abort(tx);
4102                         goto top;
4103                 }
4104                 dmu_tx_abort(tx);
4105                 ZFS_EXIT(zfsvfs);
4106                 return (error);
4107         }
4108 
4109         error = zfs_link_create(dl, szp, tx, 0);
4110 
4111         if (error == 0) {
4112                 uint64_t txtype = TX_LINK;
4113                 if (flags & FIGNORECASE)
4114                         txtype |= TX_CI;
4115                 zfs_log_link(zilog, tx, txtype, dzp, szp, name);
4116         }
4117 
4118         dmu_tx_commit(tx);
4119 
4120         zfs_dirent_unlock(dl);
4121 
4122         if (error == 0) {
4123                 vnevent_link(svp, ct);
4124         }
4125 
4126         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4127                 zil_commit(zilog, 0);
4128 
4129         ZFS_EXIT(zfsvfs);
4130         return (error);
4131 }
4132 
4133 /*
4134  * zfs_null_putapage() is used when the file system has been force
4135  * unmounted. It just drops the pages.
4136  */
4137 /* ARGSUSED */
4138 static int
4139 zfs_null_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4140     size_t *lenp, int flags, cred_t *cr)
4141 {
4142         pvn_write_done(pp, B_INVAL|B_FORCE|B_ERROR);
4143         return (0);
4144 }
4145 
4146 /*
4147  * Push a page out to disk, klustering if possible.
4148  *
4149  *      IN:     vp      - file to push page to.
4150  *              pp      - page to push.
4151  *              flags   - additional flags.
4152  *              cr      - credentials of caller.
4153  *
4154  *      OUT:    offp    - start of range pushed.
4155  *              lenp    - len of range pushed.
4156  *
4157  *      RETURN: 0 on success, error code on failure.
4158  *
4159  * NOTE: callers must have locked the page to be pushed.  On
4160  * exit, the page (and all other pages in the kluster) must be
4161  * unlocked.
4162  */
4163 /* ARGSUSED */
4164 static int
4165 zfs_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4166     size_t *lenp, int flags, cred_t *cr)
4167 {
4168         znode_t         *zp = VTOZ(vp);
4169         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4170         dmu_tx_t        *tx;
4171         u_offset_t      off, koff;
4172         size_t          len, klen;
4173         int             err;
4174 
4175         off = pp->p_offset;
4176         len = PAGESIZE;
4177         /*
4178          * If our blocksize is bigger than the page size, try to kluster
4179          * multiple pages so that we write a full block (thus avoiding
4180          * a read-modify-write).
4181          */
4182         if (off < zp->z_size && zp->z_blksz > PAGESIZE) {
4183                 klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE);
4184                 koff = ISP2(klen) ? P2ALIGN(off, (u_offset_t)klen) : 0;
4185                 ASSERT(koff <= zp->z_size);
4186                 if (koff + klen > zp->z_size)
4187                         klen = P2ROUNDUP(zp->z_size - koff, (uint64_t)PAGESIZE);
4188                 pp = pvn_write_kluster(vp, pp, &off, &len, koff, klen, flags);
4189         }
4190         ASSERT3U(btop(len), ==, btopr(len));
4191 
4192         /*
4193          * Can't push pages past end-of-file.
4194          */
4195         if (off >= zp->z_size) {
4196                 /* ignore all pages */
4197                 err = 0;
4198                 goto out;
4199         } else if (off + len > zp->z_size) {
4200                 int npages = btopr(zp->z_size - off);
4201                 page_t *trunc;
4202 
4203                 page_list_break(&pp, &trunc, npages);
4204                 /* ignore pages past end of file */
4205                 if (trunc)
4206                         pvn_write_done(trunc, flags);
4207                 len = zp->z_size - off;
4208         }
4209 
4210         if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
4211             zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
4212                 err = SET_ERROR(EDQUOT);
4213                 goto out;
4214         }
4215         tx = dmu_tx_create(zfsvfs->z_os);
4216         dmu_tx_hold_write(tx, zp->z_id, off, len);
4217 
4218         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4219         zfs_sa_upgrade_txholds(tx, zp);
4220         err = dmu_tx_assign(tx, TXG_WAIT);
4221         if (err != 0) {
4222                 dmu_tx_abort(tx);
4223                 goto out;
4224         }
4225 
4226         if (zp->z_blksz <= PAGESIZE) {
4227                 caddr_t va = zfs_map_page(pp, S_READ);
4228                 ASSERT3U(len, <=, PAGESIZE);
4229                 dmu_write(zfsvfs->z_os, zp->z_id, off, len, va, tx);
4230                 zfs_unmap_page(pp, va);
4231         } else {
4232                 err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, pp, tx);
4233         }
4234 
4235         if (err == 0) {
4236                 uint64_t mtime[2], ctime[2];
4237                 sa_bulk_attr_t bulk[3];
4238                 int count = 0;
4239 
4240                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
4241                     &mtime, 16);
4242                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
4243                     &ctime, 16);
4244                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
4245                     &zp->z_pflags, 8);
4246                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
4247                     B_TRUE);
4248                 zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off, len, 0);
4249         }
4250         dmu_tx_commit(tx);
4251 
4252 out:
4253         pvn_write_done(pp, (err ? B_ERROR : 0) | flags);
4254         if (offp)
4255                 *offp = off;
4256         if (lenp)
4257                 *lenp = len;
4258 
4259         return (err);
4260 }
4261 
4262 /*
4263  * Copy the portion of the file indicated from pages into the file.
4264  * The pages are stored in a page list attached to the files vnode.
4265  *
4266  *      IN:     vp      - vnode of file to push page data to.
4267  *              off     - position in file to put data.
4268  *              len     - amount of data to write.
4269  *              flags   - flags to control the operation.
4270  *              cr      - credentials of caller.
4271  *              ct      - caller context.
4272  *
4273  *      RETURN: 0 on success, error code on failure.
4274  *
4275  * Timestamps:
4276  *      vp - ctime|mtime updated
4277  */
4278 /*ARGSUSED*/
4279 static int
4280 zfs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
4281     caller_context_t *ct)
4282 {
4283         znode_t         *zp = VTOZ(vp);
4284         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4285         page_t          *pp;
4286         size_t          io_len;
4287         u_offset_t      io_off;
4288         uint_t          blksz;
4289         rl_t            *rl;
4290         int             error = 0;
4291 
4292         ZFS_ENTER(zfsvfs);
4293         ZFS_VERIFY_ZP(zp);
4294 
4295         /*
4296          * There's nothing to do if no data is cached.
4297          */
4298         if (!vn_has_cached_data(vp)) {
4299                 ZFS_EXIT(zfsvfs);
4300                 return (0);
4301         }
4302 
4303         /*
4304          * Align this request to the file block size in case we kluster.
4305          * XXX - this can result in pretty aggresive locking, which can
4306          * impact simultanious read/write access.  One option might be
4307          * to break up long requests (len == 0) into block-by-block
4308          * operations to get narrower locking.
4309          */
4310         blksz = zp->z_blksz;
4311         if (ISP2(blksz))
4312                 io_off = P2ALIGN_TYPED(off, blksz, u_offset_t);
4313         else
4314                 io_off = 0;
4315         if (len > 0 && ISP2(blksz))
4316                 io_len = P2ROUNDUP_TYPED(len + (off - io_off), blksz, size_t);
4317         else
4318                 io_len = 0;
4319 
4320         if (io_len == 0) {
4321                 /*
4322                  * Search the entire vp list for pages >= io_off.
4323                  */
4324                 rl = zfs_range_lock(zp, io_off, UINT64_MAX, RL_WRITER);
4325                 error = pvn_vplist_dirty(vp, io_off, zfs_putapage, flags, cr);
4326                 goto out;
4327         }
4328         rl = zfs_range_lock(zp, io_off, io_len, RL_WRITER);
4329 
4330         if (off > zp->z_size) {
4331                 /* past end of file */
4332                 zfs_range_unlock(rl);
4333                 ZFS_EXIT(zfsvfs);
4334                 return (0);
4335         }
4336 
4337         len = MIN(io_len, P2ROUNDUP(zp->z_size, PAGESIZE) - io_off);
4338 
4339         for (off = io_off; io_off < off + len; io_off += io_len) {
4340                 if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0)) {
4341                         pp = page_lookup(vp, io_off,
4342                             (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED);
4343                 } else {
4344                         pp = page_lookup_nowait(vp, io_off,
4345                             (flags & B_FREE) ? SE_EXCL : SE_SHARED);
4346                 }
4347 
4348                 if (pp != NULL && pvn_getdirty(pp, flags)) {
4349                         int err;
4350 
4351                         /*
4352                          * Found a dirty page to push
4353                          */
4354                         err = zfs_putapage(vp, pp, &io_off, &io_len, flags, cr);
4355                         if (err)
4356                                 error = err;
4357                 } else {
4358                         io_len = PAGESIZE;
4359                 }
4360         }
4361 out:
4362         zfs_range_unlock(rl);
4363         if ((flags & B_ASYNC) == 0 || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4364                 zil_commit(zfsvfs->z_log, zp->z_id);
4365         ZFS_EXIT(zfsvfs);
4366         return (error);
4367 }
4368 
4369 /*ARGSUSED*/
4370 void
4371 zfs_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
4372 {
4373         znode_t *zp = VTOZ(vp);
4374         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4375         int error;
4376 
4377         rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_READER);
4378         if (zp->z_sa_hdl == NULL) {
4379                 /*
4380                  * The fs has been unmounted, or we did a
4381                  * suspend/resume and this file no longer exists.
4382                  */
4383                 if (vn_has_cached_data(vp)) {
4384                         (void) pvn_vplist_dirty(vp, 0, zfs_null_putapage,
4385                             B_INVAL, cr);
4386                 }
4387 
4388                 mutex_enter(&zp->z_lock);
4389                 mutex_enter(&vp->v_lock);
4390                 ASSERT(vp->v_count == 1);
4391                 vp->v_count = 0;
4392                 mutex_exit(&vp->v_lock);
4393                 mutex_exit(&zp->z_lock);
4394                 rw_exit(&zfsvfs->z_teardown_inactive_lock);
4395                 zfs_znode_free(zp);
4396                 return;
4397         }
4398 
4399         /*
4400          * Attempt to push any data in the page cache.  If this fails
4401          * we will get kicked out later in zfs_zinactive().
4402          */
4403         if (vn_has_cached_data(vp)) {
4404                 (void) pvn_vplist_dirty(vp, 0, zfs_putapage, B_INVAL|B_ASYNC,
4405                     cr);
4406         }
4407 
4408         if (zp->z_atime_dirty && zp->z_unlinked == 0) {
4409                 dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);
4410 
4411                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4412                 zfs_sa_upgrade_txholds(tx, zp);
4413                 error = dmu_tx_assign(tx, TXG_WAIT);
4414                 if (error) {
4415                         dmu_tx_abort(tx);
4416                 } else {
4417                         mutex_enter(&zp->z_lock);
4418                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_ATIME(zfsvfs),
4419                             (void *)&zp->z_atime, sizeof (zp->z_atime), tx);
4420                         zp->z_atime_dirty = 0;
4421                         mutex_exit(&zp->z_lock);
4422                         dmu_tx_commit(tx);
4423                 }
4424         }
4425 
4426         zfs_zinactive(zp);
4427         rw_exit(&zfsvfs->z_teardown_inactive_lock);
4428 }
4429 
4430 /*
4431  * Bounds-check the seek operation.
4432  *
4433  *      IN:     vp      - vnode seeking within
4434  *              ooff    - old file offset
4435  *              noffp   - pointer to new file offset
4436  *              ct      - caller context
4437  *
4438  *      RETURN: 0 on success, EINVAL if new offset invalid.
4439  */
4440 /* ARGSUSED */
4441 static int
4442 zfs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp,
4443     caller_context_t *ct)
4444 {
4445         if (vp->v_type == VDIR)
4446                 return (0);
4447         return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
4448 }
4449 
4450 /*
4451  * Pre-filter the generic locking function to trap attempts to place
4452  * a mandatory lock on a memory mapped file.
4453  */
4454 static int
4455 zfs_frlock(vnode_t *vp, int cmd, flock64_t *bfp, int flag, offset_t offset,
4456     flk_callback_t *flk_cbp, cred_t *cr, caller_context_t *ct)
4457 {
4458         znode_t *zp = VTOZ(vp);
4459         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4460 
4461         ZFS_ENTER(zfsvfs);
4462         ZFS_VERIFY_ZP(zp);
4463 
4464         /*
4465          * We are following the UFS semantics with respect to mapcnt
4466          * here: If we see that the file is mapped already, then we will
4467          * return an error, but we don't worry about races between this
4468          * function and zfs_map().
4469          */
4470         if (zp->z_mapcnt > 0 && MANDMODE(zp->z_mode)) {
4471                 ZFS_EXIT(zfsvfs);
4472                 return (SET_ERROR(EAGAIN));
4473         }
4474         ZFS_EXIT(zfsvfs);
4475         return (fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ct));
4476 }
4477 
4478 /*
4479  * If we can't find a page in the cache, we will create a new page
4480  * and fill it with file data.  For efficiency, we may try to fill
4481  * multiple pages at once (klustering) to fill up the supplied page
4482  * list.  Note that the pages to be filled are held with an exclusive
4483  * lock to prevent access by other threads while they are being filled.
4484  */
4485 static int
4486 zfs_fillpage(vnode_t *vp, u_offset_t off, struct seg *seg,
4487     caddr_t addr, page_t *pl[], size_t plsz, enum seg_rw rw)
4488 {
4489         znode_t *zp = VTOZ(vp);
4490         page_t *pp, *cur_pp;
4491         objset_t *os = zp->z_zfsvfs->z_os;
4492         u_offset_t io_off, total;
4493         size_t io_len;
4494         int err;
4495 
4496         if (plsz == PAGESIZE || zp->z_blksz <= PAGESIZE) {
4497                 /*
4498                  * We only have a single page, don't bother klustering
4499                  */
4500                 io_off = off;
4501                 io_len = PAGESIZE;
4502                 pp = page_create_va(vp, io_off, io_len,
4503                     PG_EXCL | PG_WAIT, seg, addr);
4504         } else {
4505                 /*
4506                  * Try to find enough pages to fill the page list
4507                  */
4508                 pp = pvn_read_kluster(vp, off, seg, addr, &io_off,
4509                     &io_len, off, plsz, 0);
4510         }
4511         if (pp == NULL) {
4512                 /*
4513                  * The page already exists, nothing to do here.
4514                  */
4515                 *pl = NULL;
4516                 return (0);
4517         }
4518 
4519         /*
4520          * Fill the pages in the kluster.
4521          */
4522         cur_pp = pp;
4523         for (total = io_off + io_len; io_off < total; io_off += PAGESIZE) {
4524                 caddr_t va;
4525 
4526                 ASSERT3U(io_off, ==, cur_pp->p_offset);
4527                 va = zfs_map_page(cur_pp, S_WRITE);
4528                 err = dmu_read(os, zp->z_id, io_off, PAGESIZE, va,
4529                     DMU_READ_PREFETCH);
4530                 zfs_unmap_page(cur_pp, va);
4531                 if (err) {
4532                         /* On error, toss the entire kluster */
4533                         pvn_read_done(pp, B_ERROR);
4534                         /* convert checksum errors into IO errors */
4535                         if (err == ECKSUM)
4536                                 err = SET_ERROR(EIO);
4537                         return (err);
4538                 }
4539                 cur_pp = cur_pp->p_next;
4540         }
4541 
4542         /*
4543          * Fill in the page list array from the kluster starting
4544          * from the desired offset `off'.
4545          * NOTE: the page list will always be null terminated.
4546          */
4547         pvn_plist_init(pp, pl, plsz, off, io_len, rw);
4548         ASSERT(pl == NULL || (*pl)->p_offset == off);
4549 
4550         return (0);
4551 }
4552 
4553 /*
4554  * Return pointers to the pages for the file region [off, off + len]
4555  * in the pl array.  If plsz is greater than len, this function may
4556  * also return page pointers from after the specified region
4557  * (i.e. the region [off, off + plsz]).  These additional pages are
4558  * only returned if they are already in the cache, or were created as
4559  * part of a klustered read.
4560  *
4561  *      IN:     vp      - vnode of file to get data from.
4562  *              off     - position in file to get data from.
4563  *              len     - amount of data to retrieve.
4564  *              plsz    - length of provided page list.
4565  *              seg     - segment to obtain pages for.
4566  *              addr    - virtual address of fault.
4567  *              rw      - mode of created pages.
4568  *              cr      - credentials of caller.
4569  *              ct      - caller context.
4570  *
4571  *      OUT:    protp   - protection mode of created pages.
4572  *              pl      - list of pages created.
4573  *
4574  *      RETURN: 0 on success, error code on failure.
4575  *
4576  * Timestamps:
4577  *      vp - atime updated
4578  */
4579 /* ARGSUSED */
4580 static int
4581 zfs_getpage(vnode_t *vp, offset_t off, size_t len, uint_t *protp,
4582     page_t *pl[], size_t plsz, struct seg *seg, caddr_t addr,
4583     enum seg_rw rw, cred_t *cr, caller_context_t *ct)
4584 {
4585         znode_t         *zp = VTOZ(vp);
4586         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4587         page_t          **pl0 = pl;
4588         int             err = 0;
4589 
4590         /* we do our own caching, faultahead is unnecessary */
4591         if (pl == NULL)
4592                 return (0);
4593         else if (len > plsz)
4594                 len = plsz;
4595         else
4596                 len = P2ROUNDUP(len, PAGESIZE);
4597         ASSERT(plsz >= len);
4598 
4599         ZFS_ENTER(zfsvfs);
4600         ZFS_VERIFY_ZP(zp);
4601 
4602         if (protp)
4603                 *protp = PROT_ALL;
4604 
4605         /*
4606          * Loop through the requested range [off, off + len) looking
4607          * for pages.  If we don't find a page, we will need to create
4608          * a new page and fill it with data from the file.
4609          */
4610         while (len > 0) {
4611                 if (*pl = page_lookup(vp, off, SE_SHARED))
4612                         *(pl+1) = NULL;
4613                 else if (err = zfs_fillpage(vp, off, seg, addr, pl, plsz, rw))
4614                         goto out;
4615                 while (*pl) {
4616                         ASSERT3U((*pl)->p_offset, ==, off);
4617                         off += PAGESIZE;
4618                         addr += PAGESIZE;
4619                         if (len > 0) {
4620                                 ASSERT3U(len, >=, PAGESIZE);
4621                                 len -= PAGESIZE;
4622                         }
4623                         ASSERT3U(plsz, >=, PAGESIZE);
4624                         plsz -= PAGESIZE;
4625                         pl++;
4626                 }
4627         }
4628 
4629         /*
4630          * Fill out the page array with any pages already in the cache.
4631          */
4632         while (plsz > 0 &&
4633             (*pl++ = page_lookup_nowait(vp, off, SE_SHARED))) {
4634                         off += PAGESIZE;
4635                         plsz -= PAGESIZE;
4636         }
4637 out:
4638         if (err) {
4639                 /*
4640                  * Release any pages we have previously locked.
4641                  */
4642                 while (pl > pl0)
4643                         page_unlock(*--pl);
4644         } else {
4645                 ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
4646         }
4647 
4648         *pl = NULL;
4649 
4650         ZFS_EXIT(zfsvfs);
4651         return (err);
4652 }
4653 
4654 /*
4655  * Request a memory map for a section of a file.  This code interacts
4656  * with common code and the VM system as follows:
4657  *
4658  * - common code calls mmap(), which ends up in smmap_common()
4659  * - this calls VOP_MAP(), which takes you into (say) zfs
4660  * - zfs_map() calls as_map(), passing segvn_create() as the callback
4661  * - segvn_create() creates the new segment and calls VOP_ADDMAP()
4662  * - zfs_addmap() updates z_mapcnt
4663  */
4664 /*ARGSUSED*/
4665 static int
4666 zfs_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp,
4667     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4668     caller_context_t *ct)
4669 {
4670         znode_t *zp = VTOZ(vp);
4671         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4672         segvn_crargs_t  vn_a;
4673         int             error;
4674 
4675         ZFS_ENTER(zfsvfs);
4676         ZFS_VERIFY_ZP(zp);
4677 
4678         if ((prot & PROT_WRITE) && (zp->z_pflags &
4679             (ZFS_IMMUTABLE | ZFS_READONLY | ZFS_APPENDONLY))) {
4680                 ZFS_EXIT(zfsvfs);
4681                 return (SET_ERROR(EPERM));
4682         }
4683 
4684         if ((prot & (PROT_READ | PROT_EXEC)) &&
4685             (zp->z_pflags & ZFS_AV_QUARANTINED)) {
4686                 ZFS_EXIT(zfsvfs);
4687                 return (SET_ERROR(EACCES));
4688         }
4689 
4690         if (vp->v_flag & VNOMAP) {
4691                 ZFS_EXIT(zfsvfs);
4692                 return (SET_ERROR(ENOSYS));
4693         }
4694 
4695         if (off < 0 || len > MAXOFFSET_T - off) {
4696                 ZFS_EXIT(zfsvfs);
4697                 return (SET_ERROR(ENXIO));
4698         }
4699 
4700         if (vp->v_type != VREG) {
4701                 ZFS_EXIT(zfsvfs);
4702                 return (SET_ERROR(ENODEV));
4703         }
4704 
4705         /*
4706          * If file is locked, disallow mapping.
4707          */
4708         if (MANDMODE(zp->z_mode) && vn_has_flocks(vp)) {
4709                 ZFS_EXIT(zfsvfs);
4710                 return (SET_ERROR(EAGAIN));
4711         }
4712 
4713         as_rangelock(as);
4714         error = choose_addr(as, addrp, len, off, ADDR_VACALIGN, flags);
4715         if (error != 0) {
4716                 as_rangeunlock(as);
4717                 ZFS_EXIT(zfsvfs);
4718                 return (error);
4719         }
4720 
4721         vn_a.vp = vp;
4722         vn_a.offset = (u_offset_t)off;
4723         vn_a.type = flags & MAP_TYPE;
4724         vn_a.prot = prot;
4725         vn_a.maxprot = maxprot;
4726         vn_a.cred = cr;
4727         vn_a.amp = NULL;
4728         vn_a.flags = flags & ~MAP_TYPE;
4729         vn_a.szc = 0;
4730         vn_a.lgrp_mem_policy_flags = 0;
4731 
4732         error = as_map(as, *addrp, len, segvn_create, &vn_a);
4733 
4734         as_rangeunlock(as);
4735         ZFS_EXIT(zfsvfs);
4736         return (error);
4737 }
4738 
4739 /* ARGSUSED */
4740 static int
4741 zfs_addmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4742     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
4743     caller_context_t *ct)
4744 {
4745         uint64_t pages = btopr(len);
4746 
4747         atomic_add_64(&VTOZ(vp)->z_mapcnt, pages);
4748         return (0);
4749 }
4750 
4751 /*
4752  * The reason we push dirty pages as part of zfs_delmap() is so that we get a
4753  * more accurate mtime for the associated file.  Since we don't have a way of
4754  * detecting when the data was actually modified, we have to resort to
4755  * heuristics.  If an explicit msync() is done, then we mark the mtime when the
4756  * last page is pushed.  The problem occurs when the msync() call is omitted,
4757  * which by far the most common case:
4758  *
4759  *      open()
4760  *      mmap()
4761  *      <modify memory>
4762  *      munmap()
4763  *      close()
4764  *      <time lapse>
4765  *      putpage() via fsflush
4766  *
4767  * If we wait until fsflush to come along, we can have a modification time that
4768  * is some arbitrary point in the future.  In order to prevent this in the
4769  * common case, we flush pages whenever a (MAP_SHARED, PROT_WRITE) mapping is
4770  * torn down.
4771  */
4772 /* ARGSUSED */
4773 static int
4774 zfs_delmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
4775     size_t len, uint_t prot, uint_t maxprot, uint_t flags, cred_t *cr,
4776     caller_context_t *ct)
4777 {
4778         uint64_t pages = btopr(len);
4779 
4780         ASSERT3U(VTOZ(vp)->z_mapcnt, >=, pages);
4781         atomic_add_64(&VTOZ(vp)->z_mapcnt, -pages);
4782 
4783         if ((flags & MAP_SHARED) && (prot & PROT_WRITE) &&
4784             vn_has_cached_data(vp))
4785                 (void) VOP_PUTPAGE(vp, off, len, B_ASYNC, cr, ct);
4786 
4787         return (0);
4788 }
4789 
4790 /*
4791  * Free or allocate space in a file.  Currently, this function only
4792  * supports the `F_FREESP' command.  However, this command is somewhat
4793  * misnamed, as its functionality includes the ability to allocate as
4794  * well as free space.
4795  *
4796  *      IN:     vp      - vnode of file to free data in.
4797  *              cmd     - action to take (only F_FREESP supported).
4798  *              bfp     - section of file to free/alloc.
4799  *              flag    - current file open mode flags.
4800  *              offset  - current file offset.
4801  *              cr      - credentials of caller [UNUSED].
4802  *              ct      - caller context.
4803  *
4804  *      RETURN: 0 on success, error code on failure.
4805  *
4806  * Timestamps:
4807  *      vp - ctime|mtime updated
4808  */
4809 /* ARGSUSED */
4810 static int
4811 zfs_space(vnode_t *vp, int cmd, flock64_t *bfp, int flag,
4812     offset_t offset, cred_t *cr, caller_context_t *ct)
4813 {
4814         znode_t         *zp = VTOZ(vp);
4815         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4816         uint64_t        off, len;
4817         int             error;
4818 
4819         ZFS_ENTER(zfsvfs);
4820         ZFS_VERIFY_ZP(zp);
4821 
4822         if (cmd != F_FREESP) {
4823                 ZFS_EXIT(zfsvfs);
4824                 return (SET_ERROR(EINVAL));
4825         }
4826 
4827         /*
4828          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
4829          * callers might not be able to detect properly that we are read-only,
4830          * so check it explicitly here.
4831          */
4832         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
4833                 ZFS_EXIT(zfsvfs);
4834                 return (SET_ERROR(EROFS));
4835         }
4836 
4837         if (error = convoff(vp, bfp, 0, offset)) {
4838                 ZFS_EXIT(zfsvfs);
4839                 return (error);
4840         }
4841 
4842         if (bfp->l_len < 0) {
4843                 ZFS_EXIT(zfsvfs);
4844                 return (SET_ERROR(EINVAL));
4845         }
4846 
4847         off = bfp->l_start;
4848         len = bfp->l_len; /* 0 means from off to end of file */
4849 
4850         error = zfs_freesp(zp, off, len, flag, TRUE);
4851 
4852         if (error == 0 && off == 0 && len == 0)
4853                 vnevent_truncate(ZTOV(zp), ct);
4854 
4855         ZFS_EXIT(zfsvfs);
4856         return (error);
4857 }
4858 
4859 /*ARGSUSED*/
4860 static int
4861 zfs_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
4862 {
4863         znode_t         *zp = VTOZ(vp);
4864         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4865         uint32_t        gen;
4866         uint64_t        gen64;
4867         uint64_t        object = zp->z_id;
4868         zfid_short_t    *zfid;
4869         int             size, i, error;
4870 
4871         ZFS_ENTER(zfsvfs);
4872         ZFS_VERIFY_ZP(zp);
4873 
4874         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs),
4875             &gen64, sizeof (uint64_t))) != 0) {
4876                 ZFS_EXIT(zfsvfs);
4877                 return (error);
4878         }
4879 
4880         gen = (uint32_t)gen64;
4881 
4882         size = (zfsvfs->z_parent != zfsvfs) ? LONG_FID_LEN : SHORT_FID_LEN;
4883         if (fidp->fid_len < size) {
4884                 fidp->fid_len = size;
4885                 ZFS_EXIT(zfsvfs);
4886                 return (SET_ERROR(ENOSPC));
4887         }
4888 
4889         zfid = (zfid_short_t *)fidp;
4890 
4891         zfid->zf_len = size;
4892 
4893         for (i = 0; i < sizeof (zfid->zf_object); i++)
4894                 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
4895 
4896         /* Must have a non-zero generation number to distinguish from .zfs */
4897         if (gen == 0)
4898                 gen = 1;
4899         for (i = 0; i < sizeof (zfid->zf_gen); i++)
4900                 zfid->zf_gen[i] = (uint8_t)(gen >> (8 * i));
4901 
4902         if (size == LONG_FID_LEN) {
4903                 uint64_t        objsetid = dmu_objset_id(zfsvfs->z_os);
4904                 zfid_long_t     *zlfid;
4905 
4906                 zlfid = (zfid_long_t *)fidp;
4907 
4908                 for (i = 0; i < sizeof (zlfid->zf_setid); i++)
4909                         zlfid->zf_setid[i] = (uint8_t)(objsetid >> (8 * i));
4910 
4911                 /* XXX - this should be the generation number for the objset */
4912                 for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
4913                         zlfid->zf_setgen[i] = 0;
4914         }
4915 
4916         ZFS_EXIT(zfsvfs);
4917         return (0);
4918 }
4919 
4920 static int
4921 zfs_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
4922     caller_context_t *ct)
4923 {
4924         znode_t         *zp, *xzp;
4925         zfsvfs_t        *zfsvfs;
4926         zfs_dirlock_t   *dl;
4927         int             error;
4928 
4929         switch (cmd) {
4930         case _PC_LINK_MAX:
4931                 *valp = ULONG_MAX;
4932                 return (0);
4933 
4934         case _PC_FILESIZEBITS:
4935                 *valp = 64;
4936                 return (0);
4937 
4938         case _PC_XATTR_EXISTS:
4939                 zp = VTOZ(vp);
4940                 zfsvfs = zp->z_zfsvfs;
4941                 ZFS_ENTER(zfsvfs);
4942                 ZFS_VERIFY_ZP(zp);
4943                 *valp = 0;
4944                 error = zfs_dirent_lock(&dl, zp, "", &xzp,
4945                     ZXATTR | ZEXISTS | ZSHARED, NULL, NULL);
4946                 if (error == 0) {
4947                         zfs_dirent_unlock(dl);
4948                         if (!zfs_dirempty(xzp))
4949                                 *valp = 1;
4950                         VN_RELE(ZTOV(xzp));
4951                 } else if (error == ENOENT) {
4952                         /*
4953                          * If there aren't extended attributes, it's the
4954                          * same as having zero of them.
4955                          */
4956                         error = 0;
4957                 }
4958                 ZFS_EXIT(zfsvfs);
4959                 return (error);
4960 
4961         case _PC_SATTR_ENABLED:
4962         case _PC_SATTR_EXISTS:
4963                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
4964                     (vp->v_type == VREG || vp->v_type == VDIR);
4965                 return (0);
4966 
4967         case _PC_ACCESS_FILTERING:
4968                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_ACCESS_FILTER) &&
4969                     vp->v_type == VDIR;
4970                 return (0);
4971 
4972         case _PC_ACL_ENABLED:
4973                 *valp = _ACL_ACE_ENABLED;
4974                 return (0);
4975 
4976         case _PC_MIN_HOLE_SIZE:
4977                 *valp = (ulong_t)SPA_MINBLOCKSIZE;
4978                 return (0);
4979 
4980         case _PC_TIMESTAMP_RESOLUTION:
4981                 /* nanosecond timestamp resolution */
4982                 *valp = 1L;
4983                 return (0);
4984 
4985         default:
4986                 return (fs_pathconf(vp, cmd, valp, cr, ct));
4987         }
4988 }
4989 
4990 /*ARGSUSED*/
4991 static int
4992 zfs_getsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
4993     caller_context_t *ct)
4994 {
4995         znode_t *zp = VTOZ(vp);
4996         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4997         int error;
4998         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
4999 
5000         ZFS_ENTER(zfsvfs);
5001         ZFS_VERIFY_ZP(zp);
5002         error = zfs_getacl(zp, vsecp, skipaclchk, cr);
5003         ZFS_EXIT(zfsvfs);
5004 
5005         return (error);
5006 }
5007 
5008 /*ARGSUSED*/
5009 static int
5010 zfs_setsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
5011     caller_context_t *ct)
5012 {
5013         znode_t *zp = VTOZ(vp);
5014         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5015         int error;
5016         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
5017         zilog_t *zilog = zfsvfs->z_log;
5018 
5019         ZFS_ENTER(zfsvfs);
5020         ZFS_VERIFY_ZP(zp);
5021 
5022         error = zfs_setacl(zp, vsecp, skipaclchk, cr);
5023 
5024         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
5025                 zil_commit(zilog, 0);
5026 
5027         ZFS_EXIT(zfsvfs);
5028         return (error);
5029 }
5030 
5031 /*
5032  * The smallest read we may consider to loan out an arcbuf.
5033  * This must be a power of 2.
5034  */
5035 int zcr_blksz_min = (1 << 10);    /* 1K */
5036 /*
5037  * If set to less than the file block size, allow loaning out of an
5038  * arcbuf for a partial block read.  This must be a power of 2.
5039  */
5040 int zcr_blksz_max = (1 << 17);    /* 128K */
5041 
5042 /*ARGSUSED*/
5043 static int
5044 zfs_reqzcbuf(vnode_t *vp, enum uio_rw ioflag, xuio_t *xuio, cred_t *cr,
5045     caller_context_t *ct)
5046 {
5047         znode_t *zp = VTOZ(vp);
5048         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5049         int max_blksz = zfsvfs->z_max_blksz;
5050         uio_t *uio = &xuio->xu_uio;
5051         ssize_t size = uio->uio_resid;
5052         offset_t offset = uio->uio_loffset;
5053         int blksz;
5054         int fullblk, i;
5055         arc_buf_t *abuf;
5056         ssize_t maxsize;
5057         int preamble, postamble;
5058 
5059         if (xuio->xu_type != UIOTYPE_ZEROCOPY)
5060                 return (SET_ERROR(EINVAL));
5061 
5062         ZFS_ENTER(zfsvfs);
5063         ZFS_VERIFY_ZP(zp);
5064         switch (ioflag) {
5065         case UIO_WRITE:
5066                 /*
5067                  * Loan out an arc_buf for write if write size is bigger than
5068                  * max_blksz, and the file's block size is also max_blksz.
5069                  */
5070                 blksz = max_blksz;
5071                 if (size < blksz || zp->z_blksz != blksz) {
5072                         ZFS_EXIT(zfsvfs);
5073                         return (SET_ERROR(EINVAL));
5074                 }
5075                 /*
5076                  * Caller requests buffers for write before knowing where the
5077                  * write offset might be (e.g. NFS TCP write).
5078                  */
5079                 if (offset == -1) {
5080                         preamble = 0;
5081                 } else {
5082                         preamble = P2PHASE(offset, blksz);
5083                         if (preamble) {
5084                                 preamble = blksz - preamble;
5085                                 size -= preamble;
5086                         }
5087                 }
5088 
5089                 postamble = P2PHASE(size, blksz);
5090                 size -= postamble;
5091 
5092                 fullblk = size / blksz;
5093                 (void) dmu_xuio_init(xuio,
5094                     (preamble != 0) + fullblk + (postamble != 0));
5095                 DTRACE_PROBE3(zfs_reqzcbuf_align, int, preamble,
5096                     int, postamble, int,
5097                     (preamble != 0) + fullblk + (postamble != 0));
5098 
5099                 /*
5100                  * Have to fix iov base/len for partial buffers.  They
5101                  * currently represent full arc_buf's.
5102                  */
5103                 if (preamble) {
5104                         /* data begins in the middle of the arc_buf */
5105                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5106                             blksz);
5107                         ASSERT(abuf);
5108                         (void) dmu_xuio_add(xuio, abuf,
5109                             blksz - preamble, preamble);
5110                 }
5111 
5112                 for (i = 0; i < fullblk; i++) {
5113                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5114                             blksz);
5115                         ASSERT(abuf);
5116                         (void) dmu_xuio_add(xuio, abuf, 0, blksz);
5117                 }
5118 
5119                 if (postamble) {
5120                         /* data ends in the middle of the arc_buf */
5121                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5122                             blksz);
5123                         ASSERT(abuf);
5124                         (void) dmu_xuio_add(xuio, abuf, 0, postamble);
5125                 }
5126                 break;
5127         case UIO_READ:
5128                 /*
5129                  * Loan out an arc_buf for read if the read size is larger than
5130                  * the current file block size.  Block alignment is not
5131                  * considered.  Partial arc_buf will be loaned out for read.
5132                  */
5133                 blksz = zp->z_blksz;
5134                 if (blksz < zcr_blksz_min)
5135                         blksz = zcr_blksz_min;
5136                 if (blksz > zcr_blksz_max)
5137                         blksz = zcr_blksz_max;
5138                 /* avoid potential complexity of dealing with it */
5139                 if (blksz > max_blksz) {
5140                         ZFS_EXIT(zfsvfs);
5141                         return (SET_ERROR(EINVAL));
5142                 }
5143 
5144                 maxsize = zp->z_size - uio->uio_loffset;
5145                 if (size > maxsize)
5146                         size = maxsize;
5147 
5148                 if (size < blksz || vn_has_cached_data(vp)) {
5149                         ZFS_EXIT(zfsvfs);
5150                         return (SET_ERROR(EINVAL));
5151                 }
5152                 break;
5153         default:
5154                 ZFS_EXIT(zfsvfs);
5155                 return (SET_ERROR(EINVAL));
5156         }
5157 
5158         uio->uio_extflg = UIO_XUIO;
5159         XUIO_XUZC_RW(xuio) = ioflag;
5160         ZFS_EXIT(zfsvfs);
5161         return (0);
5162 }
5163 
5164 /*ARGSUSED*/
5165 static int
5166 zfs_retzcbuf(vnode_t *vp, xuio_t *xuio, cred_t *cr, caller_context_t *ct)
5167 {
5168         int i;
5169         arc_buf_t *abuf;
5170         int ioflag = XUIO_XUZC_RW(xuio);
5171 
5172         ASSERT(xuio->xu_type == UIOTYPE_ZEROCOPY);
5173 
5174         i = dmu_xuio_cnt(xuio);
5175         while (i-- > 0) {
5176                 abuf = dmu_xuio_arcbuf(xuio, i);
5177                 /*
5178                  * if abuf == NULL, it must be a write buffer
5179                  * that has been returned in zfs_write().
5180                  */
5181                 if (abuf)
5182                         dmu_return_arcbuf(abuf);
5183                 ASSERT(abuf || ioflag == UIO_WRITE);
5184         }
5185 
5186         dmu_xuio_fini(xuio);
5187         return (0);
5188 }
5189 
5190 /*
5191  * Predeclare these here so that the compiler assumes that
5192  * this is an "old style" function declaration that does
5193  * not include arguments => we won't get type mismatch errors
5194  * in the initializations that follow.
5195  */
5196 static int zfs_inval();
5197 static int zfs_isdir();
5198 
5199 static int
5200 zfs_inval()
5201 {
5202         return (SET_ERROR(EINVAL));
5203 }
5204 
5205 static int
5206 zfs_isdir()
5207 {
5208         return (SET_ERROR(EISDIR));
5209 }
5210 /*
5211  * Directory vnode operations template
5212  */
5213 vnodeops_t *zfs_dvnodeops;
5214 const fs_operation_def_t zfs_dvnodeops_template[] = {
5215         VOPNAME_OPEN,           { .vop_open = zfs_open },
5216         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5217         VOPNAME_READ,           { .error = zfs_isdir },
5218         VOPNAME_WRITE,          { .error = zfs_isdir },
5219         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5220         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5221         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5222         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5223         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5224         VOPNAME_CREATE,         { .vop_create = zfs_create },
5225         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5226         VOPNAME_LINK,           { .vop_link = zfs_link },
5227         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5228         VOPNAME_MKDIR,          { .vop_mkdir = zfs_mkdir },
5229         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5230         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5231         VOPNAME_SYMLINK,        { .vop_symlink = zfs_symlink },
5232         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5233         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5234         VOPNAME_FID,            { .vop_fid = zfs_fid },
5235         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5236         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5237         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5238         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5239         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5240         NULL,                   NULL
5241 };
5242 
5243 /*
5244  * Regular file vnode operations template
5245  */
5246 vnodeops_t *zfs_fvnodeops;
5247 const fs_operation_def_t zfs_fvnodeops_template[] = {
5248         VOPNAME_OPEN,           { .vop_open = zfs_open },
5249         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5250         VOPNAME_READ,           { .vop_read = zfs_read },
5251         VOPNAME_WRITE,          { .vop_write = zfs_write },
5252         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5253         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5254         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5255         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5256         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5257         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5258         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5259         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5260         VOPNAME_FID,            { .vop_fid = zfs_fid },
5261         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5262         VOPNAME_FRLOCK,         { .vop_frlock = zfs_frlock },
5263         VOPNAME_SPACE,          { .vop_space = zfs_space },
5264         VOPNAME_GETPAGE,        { .vop_getpage = zfs_getpage },
5265         VOPNAME_PUTPAGE,        { .vop_putpage = zfs_putpage },
5266         VOPNAME_MAP,            { .vop_map = zfs_map },
5267         VOPNAME_ADDMAP,         { .vop_addmap = zfs_addmap },
5268         VOPNAME_DELMAP,         { .vop_delmap = zfs_delmap },
5269         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5270         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5271         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5272         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5273         VOPNAME_REQZCBUF,       { .vop_reqzcbuf = zfs_reqzcbuf },
5274         VOPNAME_RETZCBUF,       { .vop_retzcbuf = zfs_retzcbuf },
5275         NULL,                   NULL
5276 };
5277 
5278 /*
5279  * Symbolic link vnode operations template
5280  */
5281 vnodeops_t *zfs_symvnodeops;
5282 const fs_operation_def_t zfs_symvnodeops_template[] = {
5283         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5284         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5285         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5286         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5287         VOPNAME_READLINK,       { .vop_readlink = zfs_readlink },
5288         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5289         VOPNAME_FID,            { .vop_fid = zfs_fid },
5290         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5291         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5292         NULL,                   NULL
5293 };
5294 
5295 /*
5296  * special share hidden files vnode operations template
5297  */
5298 vnodeops_t *zfs_sharevnodeops;
5299 const fs_operation_def_t zfs_sharevnodeops_template[] = {
5300         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5301         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5302         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5303         VOPNAME_FID,            { .vop_fid = zfs_fid },
5304         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5305         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5306         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5307         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5308         NULL,                   NULL
5309 };
5310 
5311 /*
5312  * Extended attribute directory vnode operations template
5313  *
5314  * This template is identical to the directory vnodes
5315  * operation template except for restricted operations:
5316  *      VOP_MKDIR()
5317  *      VOP_SYMLINK()
5318  *
5319  * Note that there are other restrictions embedded in:
5320  *      zfs_create()    - restrict type to VREG
5321  *      zfs_link()      - no links into/out of attribute space
5322  *      zfs_rename()    - no moves into/out of attribute space
5323  */
5324 vnodeops_t *zfs_xdvnodeops;
5325 const fs_operation_def_t zfs_xdvnodeops_template[] = {
5326         VOPNAME_OPEN,           { .vop_open = zfs_open },
5327         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5328         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5329         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5330         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5331         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5332         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5333         VOPNAME_CREATE,         { .vop_create = zfs_create },
5334         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5335         VOPNAME_LINK,           { .vop_link = zfs_link },
5336         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5337         VOPNAME_MKDIR,          { .error = zfs_inval },
5338         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5339         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5340         VOPNAME_SYMLINK,        { .error = zfs_inval },
5341         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5342         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5343         VOPNAME_FID,            { .vop_fid = zfs_fid },
5344         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5345         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5346         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5347         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5348         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5349         NULL,                   NULL
5350 };
5351 
5352 /*
5353  * Error vnode operations template
5354  */
5355 vnodeops_t *zfs_evnodeops;
5356 const fs_operation_def_t zfs_evnodeops_template[] = {
5357         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5358         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5359         NULL,                   NULL
5360 };