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