1
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
27 /* All Rights Reserved */
28
29 /*
30 * University Copyright- Copyright (c) 1982, 1986, 1988
31 * The Regents of the University of California
32 * All Rights Reserved
33 *
34 * University Acknowledgment- Portions of this document are derived from
35 * software developed by the University of California, Berkeley, and its
36 * contributors.
37 */
38
39 #include <sys/types.h>
40 #include <sys/thread.h>
41 #include <sys/t_lock.h>
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/bitmap.h>
45 #include <sys/buf.h>
46 #include <sys/cmn_err.h>
47 #include <sys/conf.h>
48 #include <sys/ddi.h>
49 #include <sys/debug.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 #include <sys/fcntl.h>
53 #include <sys/flock.h>
54 #include <sys/file.h>
55 #include <sys/kmem.h>
56 #include <sys/mman.h>
57 #include <sys/vmsystm.h>
58 #include <sys/open.h>
59 #include <sys/swap.h>
60 #include <sys/sysmacros.h>
61 #include <sys/uio.h>
62 #include <sys/vfs.h>
63 #include <sys/vfs_opreg.h>
64 #include <sys/vnode.h>
65 #include <sys/stat.h>
66 #include <sys/poll.h>
67 #include <sys/zmod.h>
68 #include <sys/fs/decomp.h>
69
70 #include <vm/hat.h>
71 #include <vm/as.h>
72 #include <vm/page.h>
73 #include <vm/pvn.h>
74 #include <vm/seg_vn.h>
75 #include <vm/seg_kmem.h>
76 #include <vm/seg_map.h>
77
78 #include <fs/fs_subr.h>
79
80 /*
81 * dcfs - A filesystem for automatic decompressing of fiocompressed files
82 *
83 * This filesystem is a layered filesystem that sits on top of a normal
84 * persistent filesystem and provides automatic decompression of files
85 * that have been previously compressed and stored on the host file system.
86 * This is a pseudo filesystem in that it does not persist data, rather it
87 * intercepts file lookup requests on the host filesystem and provides
88 * transparent decompression of those files. Currently the only supported
89 * host filesystem is ufs.
90 *
91 * A file is compressed via a userland utility (currently cmd/boot/fiocompress)
92 * and marked by fiocompress as a compressed file via a flag in the on-disk
93 * inode (set via a ufs ioctl() - see `ufs_vnops.c`ufs_ioctl()`_FIO_COMPRESSED
94 * ufs_lookup checks for this flag and if set, passes control to decompvp
95 * a function defined in this (dcfs) filesystem. decomvp uncompresses the file
96 * and returns a dcfs vnode to the VFS layer.
97 *
98 * dcfs is layered on top of ufs and passes requests involving persistence
99 * to the underlying ufs filesystem. The compressed files currently cannot be
100 * written to.
101 */
102
103
104 /*
105 * Define data structures within this file.
106 */
107 #define DCSHFT 5
108 #define DCTABLESIZE 16
109
110 #if ((DCTABLESIZE & (DCTABLESIZE - 1)) == 0)
111 #define DCHASH(vp) (((uintptr_t)(vp) >> DCSHFT) & (DCTABLESIZE - 1))
112 #else
113 #define DCHASH(vp) (((uintptr_t)(vp) >> DCSHFT) % DTABLESIZEC)
114 #endif
115
116 #define DCLRUSIZE 16
117
118 #define DCCACHESIZE 4
119
120 #define rounddown(x, y) ((x) & ~((y) - 1))
121
122 struct dcnode *dctable[DCTABLESIZE];
123
124 struct dcnode *dclru;
125 static int dclru_len;
126
127 kmutex_t dctable_lock;
128
129 dev_t dcdev;
130 struct vfs dc_vfs;
131
132 struct kmem_cache *dcnode_cache;
133 struct kmem_cache *dcbuf_cache[DCCACHESIZE];
134
135 kmutex_t dccache_lock;
136
137 static int dcinit(int, char *);
138
139 static struct dcnode *dcnode_alloc(void);
140 static void dcnode_free(struct dcnode *);
141 static void dcnode_recycle(struct dcnode *);
142
143 static void dcinsert(struct dcnode *);
144 static void dcdelete(struct dcnode *);
145 static struct dcnode *dcfind(struct vnode *);
146 static void dclru_add(struct dcnode *);
147 static void dclru_sub(struct dcnode *);
148
149
150 /*
151 * This is the loadable module wrapper.
152 */
153 #include <sys/modctl.h>
154
155 struct vfsops *dc_vfsops;
156
157 static vfsdef_t vfw = {
158 VFSDEF_VERSION,
159 "dcfs",
160 dcinit,
161 VSW_ZMOUNT,
162 NULL
163 };
164
165 /*
166 * Module linkage information for the kernel.
167 */
168 extern struct mod_ops mod_fsops;
169
170 static struct modlfs modlfs = {
171 &mod_fsops, "compressed filesystem", &vfw
172 };
173
174 static struct modlinkage modlinkage = {
175 MODREV_1, { (void *)&modlfs, NULL }
176 };
177
178 int
179 _init()
180 {
181 return (mod_install(&modlinkage));
182 }
183
184 int
185 _info(struct modinfo *modinfop)
186 {
187 return (mod_info(&modlinkage, modinfop));
188 }
189
190
191 static int dc_open(struct vnode **, int, struct cred *, caller_context_t *);
192 static int dc_close(struct vnode *, int, int, offset_t,
193 struct cred *, caller_context_t *);
194 static int dc_read(struct vnode *, struct uio *, int, struct cred *,
195 struct caller_context *);
196 static int dc_getattr(struct vnode *, struct vattr *, int,
197 struct cred *, caller_context_t *);
198 static int dc_setattr(struct vnode *, struct vattr *, int, struct cred *,
199 struct caller_context *);
200 static int dc_access(struct vnode *, int, int,
201 struct cred *, caller_context_t *);
202 static int dc_fsync(struct vnode *, int, struct cred *, caller_context_t *);
203 static void dc_inactive(struct vnode *, struct cred *, caller_context_t *);
204 static int dc_fid(struct vnode *, struct fid *, caller_context_t *);
205 static int dc_seek(struct vnode *, offset_t, offset_t *, caller_context_t *);
206 static int dc_frlock(struct vnode *, int, struct flock64 *, int, offset_t,
207 struct flk_callback *, struct cred *, caller_context_t *);
208 static int dc_realvp(struct vnode *, struct vnode **, caller_context_t *);
209 static int dc_getpage(struct vnode *, offset_t, size_t, uint_t *,
210 struct page **, size_t, struct seg *, caddr_t, enum seg_rw,
211 struct cred *, caller_context_t *);
212 static int dc_putpage(struct vnode *, offset_t, size_t, int,
213 struct cred *, caller_context_t *);
214 static int dc_map(struct vnode *, offset_t, struct as *, caddr_t *, size_t,
215 uchar_t, uchar_t, uint_t, struct cred *, caller_context_t *);
216 static int dc_addmap(struct vnode *, offset_t, struct as *, caddr_t, size_t,
217 uchar_t, uchar_t, uint_t, struct cred *, caller_context_t *);
218 static int dc_delmap(struct vnode *, offset_t, struct as *, caddr_t, size_t,
219 uint_t, uint_t, uint_t, struct cred *, caller_context_t *);
220
221 struct vnodeops *dc_vnodeops;
222
223 const fs_operation_def_t dc_vnodeops_template[] = {
224 { VOPNAME_OPEN, { .vop_open = dc_open } },
225 { VOPNAME_CLOSE, { .vop_close = dc_close } },
226 { VOPNAME_READ, { .vop_read = dc_read } },
227 { VOPNAME_GETATTR, { .vop_getattr = dc_getattr } },
228 { VOPNAME_SETATTR, { .vop_setattr = dc_setattr } },
229 { VOPNAME_ACCESS, { .vop_access = dc_access } },
230 { VOPNAME_FSYNC, { .vop_fsync = dc_fsync } },
231 { VOPNAME_INACTIVE, { .vop_inactive = dc_inactive } },
232 { VOPNAME_FID, { .vop_fid = dc_fid } },
233 { VOPNAME_SEEK, { .vop_seek = dc_seek } },
234 { VOPNAME_FRLOCK, { .vop_frlock = dc_frlock } },
235 { VOPNAME_REALVP, { .vop_realvp = dc_realvp } },
236 { VOPNAME_GETPAGE, { .vop_getpage = dc_getpage } },
237 { VOPNAME_PUTPAGE, { .vop_putpage = dc_putpage } },
238 { VOPNAME_MAP, { .vop_map = dc_map } },
239 { VOPNAME_ADDMAP, { .vop_addmap = dc_addmap } },
240 { VOPNAME_DELMAP, { .vop_delmap = dc_delmap } },
241 { NULL, { NULL } }
242 };
243
244 /*ARGSUSED*/
245 static int
246 dc_open(struct vnode **vpp, int flag, struct cred *cr, caller_context_t *ctp)
247 {
248 return (0);
249 }
250
251 /*ARGSUSED*/
252 static int
253 dc_close(struct vnode *vp, int flag, int count, offset_t off,
254 struct cred *cr, caller_context_t *ctp)
255 {
256 (void) cleanlocks(vp, ttoproc(curthread)->p_pid, 0);
257 cleanshares(vp, ttoproc(curthread)->p_pid);
258 return (0);
259 }
260
261 /*ARGSUSED*/
262 static int
263 dc_read(struct vnode *vp, struct uio *uiop, int ioflag, struct cred *cr,
264 struct caller_context *ct)
265 {
266 struct dcnode *dp = VTODC(vp);
267 size_t rdsize = MAX(MAXBSIZE, dp->dc_hdr->ch_blksize);
268 size_t fsize = dp->dc_hdr->ch_fsize;
269 int error;
270
271 /*
272 * Loop through file with segmap, decompression will occur
273 * in dc_getapage
274 */
275 do {
276 caddr_t base;
277 size_t n;
278 offset_t mapon;
279
280 /*
281 * read to end of block or file
282 */
283 mapon = uiop->uio_loffset & (rdsize - 1);
284 n = MIN(rdsize - mapon, uiop->uio_resid);
285 n = MIN(n, fsize - uiop->uio_loffset);
286 if (n == 0)
287 return (0); /* at EOF */
288
289 base = segmap_getmapflt(segkmap, vp, uiop->uio_loffset, n, 1,
290 S_READ);
291 error = uiomove(base + mapon, n, UIO_READ, uiop);
292 if (!error) {
293 uint_t flags;
294
295 if (n + mapon == rdsize || uiop->uio_loffset == fsize)
296 flags = SM_DONTNEED;
297 else
298 flags = 0;
299 error = segmap_release(segkmap, base, flags);
300 } else
301 (void) segmap_release(segkmap, base, 0);
302 } while (!error && uiop->uio_resid);
303
304 return (error);
305 }
306
307 static int
308 dc_getattr(struct vnode *vp, struct vattr *vap, int flags,
309 cred_t *cred, caller_context_t *ctp)
310 {
311 struct dcnode *dp = VTODC(vp);
312 struct vnode *subvp = dp->dc_subvp;
313 int error;
314
315 error = VOP_GETATTR(subvp, vap, flags, cred, ctp);
316
317 /* substitute uncompressed size */
318 vap->va_size = dp->dc_hdr->ch_fsize;
319 return (error);
320 }
321
322 static int
323 dc_setattr(struct vnode *vp, struct vattr *vap, int flags, cred_t *cred,
324 caller_context_t *ctp)
325 {
326 struct dcnode *dp = VTODC(vp);
327 struct vnode *subvp = dp->dc_subvp;
328
329 return (VOP_SETATTR(subvp, vap, flags, cred, ctp));
330 }
331
332 static int
333 dc_access(struct vnode *vp, int mode, int flags,
334 cred_t *cred, caller_context_t *ctp)
335 {
336 struct dcnode *dp = VTODC(vp);
337 struct vnode *subvp = dp->dc_subvp;
338
339 return (VOP_ACCESS(subvp, mode, flags, cred, ctp));
340 }
341
342 /*ARGSUSED*/
343 static int
344 dc_fsync(vnode_t *vp, int syncflag, cred_t *cred, caller_context_t *ctp)
345 {
346 return (0);
347 }
348
349 /*ARGSUSED*/
350 static void
351 dc_inactive(struct vnode *vp, cred_t *cr, caller_context_t *ctp)
352 {
353 struct dcnode *dp = VTODC(vp);
354
355 mutex_enter(&dctable_lock);
356 mutex_enter(&vp->v_lock);
357 ASSERT(vp->v_count >= 1);
358 if (--vp->v_count != 0) {
359 /*
360 * Somebody accessed the dcnode before we got a chance to
361 * remove it. They will remove it when they do a vn_rele.
362 */
363 mutex_exit(&vp->v_lock);
364 mutex_exit(&dctable_lock);
365 return;
366 }
367 mutex_exit(&vp->v_lock);
368
369 dcnode_free(dp);
370
371 mutex_exit(&dctable_lock);
372 }
373
374 static int
375 dc_fid(struct vnode *vp, struct fid *fidp, caller_context_t *ctp)
376 {
377 struct dcnode *dp = VTODC(vp);
378 struct vnode *subvp = dp->dc_subvp;
379
380 return (VOP_FID(subvp, fidp, ctp));
381 }
382
383 static int
384 dc_seek(struct vnode *vp, offset_t oof, offset_t *noffp, caller_context_t *ctp)
385 {
386 struct dcnode *dp = VTODC(vp);
387 struct vnode *subvp = dp->dc_subvp;
388
389 return (VOP_SEEK(subvp, oof, noffp, ctp));
390 }
391
392 static int
393 dc_frlock(struct vnode *vp, int cmd, struct flock64 *bfp, int flag,
394 offset_t offset, struct flk_callback *flk_cbp,
395 cred_t *cr, caller_context_t *ctp)
396 {
397 struct dcnode *dp = VTODC(vp);
398 int error;
399 struct vattr vattr;
400
401 /*
402 * If file is being mapped, disallow frlock.
403 */
404 vattr.va_mask = AT_MODE;
405 if (error = VOP_GETATTR(dp->dc_subvp, &vattr, 0, cr, ctp))
406 return (error);
407 if (dp->dc_mapcnt > 0 && MANDLOCK(vp, vattr.va_mode))
408 return (EAGAIN);
409
410 return (fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ctp));
411 }
412
413 /*ARGSUSED*/
414 static int
415 dc_getblock_miss(struct vnode *vp, offset_t off, size_t len, struct page **ppp,
416 struct seg *seg, caddr_t addr, enum seg_rw rw, struct cred *cr)
417 {
418 struct dcnode *dp = VTODC(vp);
419 struct comphdr *hdr = dp->dc_hdr;
420 struct page *pp;
421 struct buf *bp;
422 caddr_t saddr;
423 off_t cblkno;
424 size_t rdoff, rdsize, dsize;
425 long xlen;
426 int error, zerr;
427
428 ASSERT(len == hdr->ch_blksize);
429 /*
430 * Get destination pages and make them addressable
431 */
432 pp = page_create_va(vp, off, len, PG_WAIT, seg, addr);
433 bp = pageio_setup(pp, len, vp, B_READ);
434 bp_mapin(bp);
435
436 /*
437 * read compressed data from subordinate vnode
438 */
439 saddr = kmem_cache_alloc(dp->dc_bufcache, KM_SLEEP);
440 cblkno = off / len;
441 rdoff = hdr->ch_blkmap[cblkno];
442 rdsize = hdr->ch_blkmap[cblkno + 1] - rdoff;
443 error = vn_rdwr(UIO_READ, dp->dc_subvp, saddr, rdsize, rdoff,
444 UIO_SYSSPACE, 0, 0, cr, NULL);
445 if (error)
446 goto cleanup;
447
448 /*
449 * Uncompress
450 */
451 dsize = len;
452 zerr = z_uncompress(bp->b_un.b_addr, &dsize, saddr, dp->dc_zmax);
453 if (zerr != Z_OK) {
454 error = EIO;
455 goto cleanup;
456 }
457
458 /*
459 * Handle EOF
460 */
461 xlen = hdr->ch_fsize - off;
462 if (xlen < len) {
463 bzero(bp->b_un.b_addr + xlen, len - xlen);
464 if (dsize != xlen)
465 error = EIO;
466 } else if (dsize != len)
467 error = EIO;
468
469 /*
470 * Clean up
471 */
472 cleanup:
473 kmem_cache_free(dp->dc_bufcache, saddr);
474 pageio_done(bp);
475 *ppp = pp;
476 return (error);
477 }
478
479 static int
480 dc_getblock(struct vnode *vp, offset_t off, size_t len, struct page **ppp,
481 struct seg *seg, caddr_t addr, enum seg_rw rw, struct cred *cr)
482 {
483 struct page *pp, *plist = NULL;
484 offset_t pgoff;
485 int rdblk;
486
487 /*
488 * pvn_read_kluster() doesn't quite do what we want, since it
489 * thinks sub block reads are ok. Here we always decompress
490 * a full block.
491 */
492
493 /*
494 * Check page cache
495 */
496 rdblk = 0;
497 for (pgoff = off; pgoff < off + len; pgoff += PAGESIZE) {
498 pp = page_lookup(vp, pgoff, SE_EXCL);
499 if (pp == NULL) {
500 rdblk = 1;
501 break;
502 }
503 page_io_lock(pp);
504 page_add(&plist, pp);
505 plist = plist->p_next;
506 }
507 if (!rdblk) {
508 *ppp = plist;
509 return (0); /* all pages in cache */
510 }
511
512 /*
513 * Undo any locks so getblock_miss has an open field
514 */
515 if (plist != NULL)
516 pvn_io_done(plist);
517
518 return (dc_getblock_miss(vp, off, len, ppp, seg, addr, rw, cr));
519 }
520
521 static int
522 dc_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
523 {
524 struct vnode *rvp;
525
526 vp = VTODC(vp)->dc_subvp;
527 if (VOP_REALVP(vp, &rvp, ct) == 0)
528 vp = rvp;
529 *vpp = vp;
530 return (0);
531 }
532
533 /*ARGSUSED10*/
534 static int
535 dc_getpage(struct vnode *vp, offset_t off, size_t len, uint_t *protp,
536 struct page *pl[], size_t plsz, struct seg *seg, caddr_t addr,
537 enum seg_rw rw, struct cred *cr, caller_context_t *ctp)
538 {
539 struct dcnode *dp = VTODC(vp);
540 struct comphdr *hdr = dp->dc_hdr;
541 struct page *pp, *plist = NULL;
542 caddr_t vp_baddr;
543 offset_t vp_boff, vp_bend;
544 size_t bsize = hdr->ch_blksize;
545 int nblks, error;
546
547 /* does not support write */
548 if (rw == S_WRITE) {
549 panic("write attempt on compressed file");
550 /*NOTREACHED*/
551 }
552
553 if (protp)
554 *protp = PROT_ALL;
555 /*
556 * We don't support asynchronous operation at the moment, so
557 * just pretend we did it. If the pages are ever actually
558 * needed, they'll get brought in then.
559 */
560 if (pl == NULL)
561 return (0);
562
563 /*
564 * Calc block start and end offsets
565 */
566 vp_boff = rounddown(off, bsize);
567 vp_bend = roundup(off + len, bsize);
568 vp_baddr = (caddr_t)rounddown((uintptr_t)addr, bsize);
569
570 nblks = (vp_bend - vp_boff) / bsize;
571 while (nblks--) {
572 error = dc_getblock(vp, vp_boff, bsize, &pp, seg, vp_baddr,
573 rw, cr);
574 page_list_concat(&plist, &pp);
575 vp_boff += bsize;
576 vp_baddr += bsize;
577 }
578 if (!error)
579 pvn_plist_init(plist, pl, plsz, off, len, rw);
580 else
581 pvn_read_done(plist, B_ERROR);
582 return (error);
583 }
584
585 /*
586 * This function should never be called. We need to have it to pass
587 * it as an argument to other functions.
588 */
589 /*ARGSUSED*/
590 static int
591 dc_putapage(struct vnode *vp, struct page *pp, u_offset_t *offp, size_t *lenp,
592 int flags, struct cred *cr)
593 {
594 /* should never happen */
595 cmn_err(CE_PANIC, "dcfs: dc_putapage: dirty page");
596 /*NOTREACHED*/
597 return (0);
598 }
599
600
601 /*
602 * The only flags we support are B_INVAL, B_FREE and B_DONTNEED.
603 * B_INVAL is set by:
604 *
605 * 1) the MC_SYNC command of memcntl(2) to support the MS_INVALIDATE flag.
606 * 2) the MC_ADVISE command of memcntl(2) with the MADV_DONTNEED advice
607 * which translates to an MC_SYNC with the MS_INVALIDATE flag.
608 *
609 * The B_FREE (as well as the B_DONTNEED) flag is set when the
610 * MADV_SEQUENTIAL advice has been used. VOP_PUTPAGE is invoked
611 * from SEGVN to release pages behind a pagefault.
612 */
613 /*ARGSUSED5*/
614 static int
615 dc_putpage(struct vnode *vp, offset_t off, size_t len, int flags,
616 struct cred *cr, caller_context_t *ctp)
617 {
618 int error = 0;
619
620 if (vp->v_count == 0) {
621 panic("dcfs_putpage: bad v_count");
622 /*NOTREACHED*/
623 }
624
625 if (vp->v_flag & VNOMAP)
626 return (ENOSYS);
627
628 if (!vn_has_cached_data(vp)) /* no pages mapped */
629 return (0);
630
631 if (len == 0) /* from 'off' to EOF */
632 error = pvn_vplist_dirty(vp, off, dc_putapage, flags, cr);
633 else {
634 offset_t io_off;
635 se_t se = (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED;
636
637 for (io_off = off; io_off < off + len; io_off += PAGESIZE) {
638 page_t *pp;
639
640 /*
641 * We insist on getting the page only if we are
642 * about to invalidate, free or write it and
643 * the B_ASYNC flag is not set.
644 */
645 if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0))
646 pp = page_lookup(vp, io_off, se);
647 else
648 pp = page_lookup_nowait(vp, io_off, se);
649
650 if (pp == NULL)
651 continue;
652 /*
653 * Normally pvn_getdirty() should return 0, which
654 * impies that it has done the job for us.
655 * The shouldn't-happen scenario is when it returns 1.
656 * This means that the page has been modified and
657 * needs to be put back.
658 * Since we can't write to a dcfs compressed file,
659 * we fake a failed I/O and force pvn_write_done()
660 * to destroy the page.
661 */
662 if (pvn_getdirty(pp, flags) == 1) {
663 cmn_err(CE_NOTE, "dc_putpage: dirty page");
664 pvn_write_done(pp, flags |
665 B_ERROR | B_WRITE | B_INVAL | B_FORCE);
666 }
667 }
668 }
669 return (error);
670 }
671
672 static int
673 dc_map(struct vnode *vp, offset_t off, struct as *as, caddr_t *addrp,
674 size_t len, uchar_t prot, uchar_t maxprot, uint_t flags,
675 struct cred *cred, caller_context_t *ctp)
676 {
677 struct vattr vattr;
678 struct segvn_crargs vn_a;
679 int error;
680
681 if (vp->v_flag & VNOMAP)
682 return (ENOSYS);
683
684 if (off < (offset_t)0 || (offset_t)(off + len) < (offset_t)0)
685 return (ENXIO);
686
687 /*
688 * If file is being locked, disallow mapping.
689 */
690 if (error = VOP_GETATTR(VTODC(vp)->dc_subvp, &vattr, 0, cred, ctp))
691 return (error);
692 if (vn_has_mandatory_locks(vp, vattr.va_mode))
693 return (EAGAIN);
694
695 as_rangelock(as);
696
697 if ((flags & MAP_FIXED) == 0) {
698 map_addr(addrp, len, off, 1, flags);
699 if (*addrp == NULL) {
700 as_rangeunlock(as);
701 return (ENOMEM);
702 }
703 } else {
704 /*
705 * User specified address - blow away any previous mappings
706 */
707 (void) as_unmap(as, *addrp, len);
708 }
709
710 vn_a.vp = vp;
711 vn_a.offset = off;
712 vn_a.type = flags & MAP_TYPE;
713 vn_a.prot = prot;
714 vn_a.maxprot = maxprot;
715 vn_a.flags = flags & ~MAP_TYPE;
716 vn_a.cred = cred;
717 vn_a.amp = NULL;
718 vn_a.szc = 0;
719 vn_a.lgrp_mem_policy_flags = 0;
720
721 error = as_map(as, *addrp, len, segvn_create, &vn_a);
722 as_rangeunlock(as);
723 return (error);
724 }
725
726 /*ARGSUSED*/
727 static int
728 dc_addmap(struct vnode *vp, offset_t off, struct as *as, caddr_t addr,
729 size_t len, uchar_t prot, uchar_t maxprot, uint_t flags,
730 struct cred *cr, caller_context_t *ctp)
731 {
732 struct dcnode *dp;
733
734 if (vp->v_flag & VNOMAP)
735 return (ENOSYS);
736
737 dp = VTODC(vp);
738 mutex_enter(&dp->dc_lock);
739 dp->dc_mapcnt += btopr(len);
740 mutex_exit(&dp->dc_lock);
741 return (0);
742 }
743
744 /*ARGSUSED*/
745 static int
746 dc_delmap(struct vnode *vp, offset_t off, struct as *as, caddr_t addr,
747 size_t len, uint_t prot, uint_t maxprot, uint_t flags,
748 struct cred *cr, caller_context_t *ctp)
749 {
750 struct dcnode *dp;
751
752 if (vp->v_flag & VNOMAP)
753 return (ENOSYS);
754
755 dp = VTODC(vp);
756 mutex_enter(&dp->dc_lock);
757 dp->dc_mapcnt -= btopr(len);
758 ASSERT(dp->dc_mapcnt >= 0);
759 mutex_exit(&dp->dc_lock);
760 return (0);
761 }
762
763 /*
764 * Constructor/destructor routines for dcnodes
765 */
766 /*ARGSUSED1*/
767 static int
768 dcnode_constructor(void *buf, void *cdrarg, int kmflags)
769 {
770 struct dcnode *dp = buf;
771 struct vnode *vp;
772
773 vp = dp->dc_vp = vn_alloc(kmflags);
774 if (vp == NULL) {
775 return (-1);
776 }
777 vp->v_data = dp;
778 vp->v_type = VREG;
779 vp->v_flag = VNOSWAP;
780 vp->v_vfsp = &dc_vfs;
781 vn_setops(vp, dc_vnodeops);
782 vn_exists(vp);
783
784 mutex_init(&dp->dc_lock, NULL, MUTEX_DEFAULT, NULL);
785 dp->dc_mapcnt = 0;
786 dp->dc_lrunext = dp->dc_lruprev = NULL;
787 dp->dc_hdr = NULL;
788 dp->dc_subvp = NULL;
789 return (0);
790 }
791
792 /*ARGSUSED*/
793 static void
794 dcnode_destructor(void *buf, void *cdrarg)
795 {
796 struct dcnode *dp = buf;
797 struct vnode *vp = DCTOV(dp);
798
799 mutex_destroy(&dp->dc_lock);
800
801 VERIFY(dp->dc_hdr == NULL);
802 VERIFY(dp->dc_subvp == NULL);
803 vn_invalid(vp);
804 vn_free(vp);
805 }
806
807 static struct dcnode *
808 dcnode_alloc(void)
809 {
810 struct dcnode *dp;
811
812 /*
813 * If the free list is above DCLRUSIZE
814 * re-use one from it
815 */
816 mutex_enter(&dctable_lock);
817 if (dclru_len < DCLRUSIZE) {
818 mutex_exit(&dctable_lock);
819 dp = kmem_cache_alloc(dcnode_cache, KM_SLEEP);
820 } else {
821 ASSERT(dclru != NULL);
822 dp = dclru;
823 dclru_sub(dp);
824 dcdelete(dp);
825 mutex_exit(&dctable_lock);
826 dcnode_recycle(dp);
827 }
828 return (dp);
829 }
830
831 static void
832 dcnode_free(struct dcnode *dp)
833 {
834 struct vnode *vp = DCTOV(dp);
835
836 ASSERT(MUTEX_HELD(&dctable_lock));
837
838 /*
839 * If no cached pages, no need to put it on lru
840 */
841 if (!vn_has_cached_data(vp)) {
842 dcdelete(dp);
843 dcnode_recycle(dp);
844 kmem_cache_free(dcnode_cache, dp);
845 return;
846 }
847
848 /*
849 * Add to lru, if it's over the limit, free from head
850 */
851 dclru_add(dp);
852 if (dclru_len > DCLRUSIZE) {
853 dp = dclru;
854 dclru_sub(dp);
855 dcdelete(dp);
856 dcnode_recycle(dp);
857 kmem_cache_free(dcnode_cache, dp);
858 }
859 }
860
861 static void
862 dcnode_recycle(struct dcnode *dp)
863 {
864 struct vnode *vp;
865
866 vp = DCTOV(dp);
867
868 VN_RELE(dp->dc_subvp);
869 dp->dc_subvp = NULL;
870 (void) pvn_vplist_dirty(vp, 0, dc_putapage, B_INVAL, NULL);
871 kmem_free(dp->dc_hdr, dp->dc_hdrsize);
872 dp->dc_hdr = NULL;
873 dp->dc_hdrsize = dp->dc_zmax = 0;
874 dp->dc_bufcache = NULL;
875 dp->dc_mapcnt = 0;
876 vn_reinit(vp);
877 vp->v_type = VREG;
878 vp->v_flag = VNOSWAP;
879 vp->v_vfsp = &dc_vfs;
880 }
881
882 static int
883 dcinit(int fstype, char *name)
884 {
885 static const fs_operation_def_t dc_vfsops_template[] = {
886 { NULL, { NULL } }
887 };
888 int error;
889 major_t dev;
890
891 error = vfs_setfsops(fstype, dc_vfsops_template, &dc_vfsops);
892 if (error) {
893 cmn_err(CE_WARN, "dcinit: bad vfs ops template");
894 return (error);
895 }
896 VFS_INIT(&dc_vfs, dc_vfsops, NULL);
897 dc_vfs.vfs_flag = VFS_RDONLY;
898 dc_vfs.vfs_fstype = fstype;
899 if ((dev = getudev()) == (major_t)-1)
900 dev = 0;
901 dcdev = makedevice(dev, 0);
902 dc_vfs.vfs_dev = dcdev;
903
904 error = vn_make_ops(name, dc_vnodeops_template, &dc_vnodeops);
905 if (error != 0) {
906 (void) vfs_freevfsops_by_type(fstype);
907 cmn_err(CE_WARN, "dcinit: bad vnode ops template");
908 return (error);
909 }
910
911 mutex_init(&dctable_lock, NULL, MUTEX_DEFAULT, NULL);
912 mutex_init(&dccache_lock, NULL, MUTEX_DEFAULT, NULL);
913 dcnode_cache = kmem_cache_create("dcnode_cache", sizeof (struct dcnode),
914 0, dcnode_constructor, dcnode_destructor, NULL, NULL, NULL, 0);
915
916 return (0);
917 }
918
919 /*
920 * Return shadow vnode with the given vp as its subordinate
921 */
922 struct vnode *
923 decompvp(struct vnode *vp, cred_t *cred, caller_context_t *ctp)
924 {
925 struct dcnode *dp, *ndp;
926 struct comphdr thdr, *hdr;
927 struct kmem_cache **cpp;
928 struct vattr vattr;
929 size_t hdrsize, bsize;
930 int error;
931
932 /*
933 * See if we have an existing shadow
934 * If none, we have to manufacture one
935 */
936 mutex_enter(&dctable_lock);
937 dp = dcfind(vp);
938 mutex_exit(&dctable_lock);
939 if (dp != NULL)
940 return (DCTOV(dp));
941
942 /*
943 * Make sure it's a valid compressed file
944 */
945 hdr = &thdr;
946 error = vn_rdwr(UIO_READ, vp, (caddr_t)hdr, sizeof (struct comphdr), 0,
947 UIO_SYSSPACE, 0, 0, cred, NULL);
948 if (error || hdr->ch_magic != CH_MAGIC_ZLIB ||
949 hdr->ch_version != CH_VERSION || hdr->ch_algorithm != CH_ALG_ZLIB ||
950 hdr->ch_fsize == 0 || hdr->ch_blksize < PAGESIZE ||
951 hdr->ch_blksize > ptob(DCCACHESIZE) || !ISP2(hdr->ch_blksize))
952 return (NULL);
953
954 /* get underlying file size */
955 if (VOP_GETATTR(vp, &vattr, 0, cred, ctp) != 0)
956 return (NULL);
957
958 /*
959 * Re-read entire header
960 */
961 hdrsize = hdr->ch_blkmap[0] + sizeof (uint64_t);
962 hdr = kmem_alloc(hdrsize, KM_SLEEP);
963 error = vn_rdwr(UIO_READ, vp, (caddr_t)hdr, hdrsize, 0, UIO_SYSSPACE,
964 0, 0, cred, NULL);
965 if (error) {
966 kmem_free(hdr, hdrsize);
967 return (NULL);
968 }
969
970 /*
971 * add extra blkmap entry to make dc_getblock()'s
972 * life easier
973 */
974 bsize = hdr->ch_blksize;
975 hdr->ch_blkmap[((hdr->ch_fsize-1) / bsize) + 1] = vattr.va_size;
976
977 ndp = dcnode_alloc();
978 ndp->dc_subvp = vp;
979 VN_HOLD(vp);
980 ndp->dc_hdr = hdr;
981 ndp->dc_hdrsize = hdrsize;
982
983 /*
984 * Allocate kmem cache if none there already
985 */
986 ndp->dc_zmax = ZMAXBUF(bsize);
987 cpp = &dcbuf_cache[btop(bsize)];
988 mutex_enter(&dccache_lock);
989 if (*cpp == NULL)
990 *cpp = kmem_cache_create("dcbuf_cache", ndp->dc_zmax, 0, NULL,
991 NULL, NULL, NULL, NULL, 0);
992 mutex_exit(&dccache_lock);
993 ndp->dc_bufcache = *cpp;
994
995 /*
996 * Recheck table in case someone else created shadow
997 * while we were blocked above.
998 */
999 mutex_enter(&dctable_lock);
1000 dp = dcfind(vp);
1001 if (dp != NULL) {
1002 mutex_exit(&dctable_lock);
1003 dcnode_recycle(ndp);
1004 kmem_cache_free(dcnode_cache, ndp);
1005 return (DCTOV(dp));
1006 }
1007 dcinsert(ndp);
1008 mutex_exit(&dctable_lock);
1009
1010 return (DCTOV(ndp));
1011 }
1012
1013
1014 /*
1015 * dcnode lookup table
1016 * These routines maintain a table of dcnodes hashed by their
1017 * subordinate vnode so that they can be found if they already
1018 * exist in the vnode cache
1019 */
1020
1021 /*
1022 * Put a dcnode in the table.
1023 */
1024 static void
1025 dcinsert(struct dcnode *newdp)
1026 {
1027 int idx = DCHASH(newdp->dc_subvp);
1028
1029 ASSERT(MUTEX_HELD(&dctable_lock));
1030 newdp->dc_hash = dctable[idx];
1031 dctable[idx] = newdp;
1032 }
1033
1034 /*
1035 * Remove a dcnode from the hash table.
1036 */
1037 void
1038 dcdelete(struct dcnode *deldp)
1039 {
1040 int idx = DCHASH(deldp->dc_subvp);
1041 struct dcnode *dp, *prevdp;
1042
1043 ASSERT(MUTEX_HELD(&dctable_lock));
1044 dp = dctable[idx];
1045 if (dp == deldp)
1046 dctable[idx] = dp->dc_hash;
1047 else {
1048 for (prevdp = dp, dp = dp->dc_hash; dp != NULL;
1049 prevdp = dp, dp = dp->dc_hash) {
1050 if (dp == deldp) {
1051 prevdp->dc_hash = dp->dc_hash;
1052 break;
1053 }
1054 }
1055 }
1056 ASSERT(dp != NULL);
1057 }
1058
1059 /*
1060 * Find a shadow vnode in the dctable hash list.
1061 */
1062 static struct dcnode *
1063 dcfind(struct vnode *vp)
1064 {
1065 struct dcnode *dp;
1066
1067 ASSERT(MUTEX_HELD(&dctable_lock));
1068 for (dp = dctable[DCHASH(vp)]; dp != NULL; dp = dp->dc_hash)
1069 if (dp->dc_subvp == vp) {
1070 VN_HOLD(DCTOV(dp));
1071 if (dp->dc_lrunext)
1072 dclru_sub(dp);
1073 return (dp);
1074 }
1075 return (NULL);
1076 }
1077
1078 #ifdef DEBUG
1079 static int
1080 dclru_count(void)
1081 {
1082 struct dcnode *dp;
1083 int i = 0;
1084
1085 if (dclru == NULL)
1086 return (0);
1087 for (dp = dclru; dp->dc_lrunext != dclru; dp = dp->dc_lrunext)
1088 i++;
1089 return (i + 1);
1090 }
1091 #endif
1092
1093 static void
1094 dclru_add(struct dcnode *dp)
1095 {
1096 /*
1097 * Add to dclru as double-link chain
1098 */
1099 ASSERT(MUTEX_HELD(&dctable_lock));
1100 if (dclru == NULL) {
1101 dclru = dp;
1102 dp->dc_lruprev = dp->dc_lrunext = dp;
1103 } else {
1104 struct dcnode *last = dclru->dc_lruprev;
1105
1106 dclru->dc_lruprev = dp;
1107 last->dc_lrunext = dp;
1108 dp->dc_lruprev = last;
1109 dp->dc_lrunext = dclru;
1110 }
1111 dclru_len++;
1112 ASSERT(dclru_len == dclru_count());
1113 }
1114
1115 static void
1116 dclru_sub(struct dcnode *dp)
1117 {
1118 ASSERT(MUTEX_HELD(&dctable_lock));
1119 dp->dc_lrunext->dc_lruprev = dp->dc_lruprev;
1120 dp->dc_lruprev->dc_lrunext = dp->dc_lrunext;
1121 if (dp == dclru)
1122 dclru = dp->dc_lrunext == dp ? NULL : dp->dc_lrunext;
1123 dp->dc_lrunext = dp->dc_lruprev = NULL;
1124 dclru_len--;
1125 ASSERT(dclru_len == dclru_count());
1126 }