aboutsummaryrefslogtreecommitdiffstats
path: root/fs/xfs/xfs_filestream.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/xfs/xfs_filestream.c')
-rw-r--r--fs/xfs/xfs_filestream.c771
1 files changed, 771 insertions, 0 deletions
diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
new file mode 100644
index 000000000000..ce2278611bb7
--- /dev/null
+++ b/fs/xfs/xfs_filestream.c
@@ -0,0 +1,771 @@
1/*
2 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_bmap_btree.h"
20#include "xfs_inum.h"
21#include "xfs_dir2.h"
22#include "xfs_dir2_sf.h"
23#include "xfs_attr_sf.h"
24#include "xfs_dinode.h"
25#include "xfs_inode.h"
26#include "xfs_ag.h"
27#include "xfs_dmapi.h"
28#include "xfs_log.h"
29#include "xfs_trans.h"
30#include "xfs_sb.h"
31#include "xfs_mount.h"
32#include "xfs_bmap.h"
33#include "xfs_alloc.h"
34#include "xfs_utils.h"
35#include "xfs_mru_cache.h"
36#include "xfs_filestream.h"
37
38#ifdef XFS_FILESTREAMS_TRACE
39
40ktrace_t *xfs_filestreams_trace_buf;
41
42STATIC void
43xfs_filestreams_trace(
44 xfs_mount_t *mp, /* mount point */
45 int type, /* type of trace */
46 const char *func, /* source function */
47 int line, /* source line number */
48 __psunsigned_t arg0,
49 __psunsigned_t arg1,
50 __psunsigned_t arg2,
51 __psunsigned_t arg3,
52 __psunsigned_t arg4,
53 __psunsigned_t arg5)
54{
55 ktrace_enter(xfs_filestreams_trace_buf,
56 (void *)(__psint_t)(type | (line << 16)),
57 (void *)func,
58 (void *)(__psunsigned_t)current_pid(),
59 (void *)mp,
60 (void *)(__psunsigned_t)arg0,
61 (void *)(__psunsigned_t)arg1,
62 (void *)(__psunsigned_t)arg2,
63 (void *)(__psunsigned_t)arg3,
64 (void *)(__psunsigned_t)arg4,
65 (void *)(__psunsigned_t)arg5,
66 NULL, NULL, NULL, NULL, NULL, NULL);
67}
68
69#define TRACE0(mp,t) TRACE6(mp,t,0,0,0,0,0,0)
70#define TRACE1(mp,t,a0) TRACE6(mp,t,a0,0,0,0,0,0)
71#define TRACE2(mp,t,a0,a1) TRACE6(mp,t,a0,a1,0,0,0,0)
72#define TRACE3(mp,t,a0,a1,a2) TRACE6(mp,t,a0,a1,a2,0,0,0)
73#define TRACE4(mp,t,a0,a1,a2,a3) TRACE6(mp,t,a0,a1,a2,a3,0,0)
74#define TRACE5(mp,t,a0,a1,a2,a3,a4) TRACE6(mp,t,a0,a1,a2,a3,a4,0)
75#define TRACE6(mp,t,a0,a1,a2,a3,a4,a5) \
76 xfs_filestreams_trace(mp, t, __FUNCTION__, __LINE__, \
77 (__psunsigned_t)a0, (__psunsigned_t)a1, \
78 (__psunsigned_t)a2, (__psunsigned_t)a3, \
79 (__psunsigned_t)a4, (__psunsigned_t)a5)
80
81#define TRACE_AG_SCAN(mp, ag, ag2) \
82 TRACE2(mp, XFS_FSTRM_KTRACE_AGSCAN, ag, ag2);
83#define TRACE_AG_PICK1(mp, max_ag, maxfree) \
84 TRACE2(mp, XFS_FSTRM_KTRACE_AGPICK1, max_ag, maxfree);
85#define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag) \
86 TRACE6(mp, XFS_FSTRM_KTRACE_AGPICK2, ag, ag2, \
87 cnt, free, scan, flag)
88#define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2) \
89 TRACE5(mp, XFS_FSTRM_KTRACE_UPDATE, ip, ag, cnt, ag2, cnt2)
90#define TRACE_FREE(mp, ip, pip, ag, cnt) \
91 TRACE4(mp, XFS_FSTRM_KTRACE_FREE, ip, pip, ag, cnt)
92#define TRACE_LOOKUP(mp, ip, pip, ag, cnt) \
93 TRACE4(mp, XFS_FSTRM_KTRACE_ITEM_LOOKUP, ip, pip, ag, cnt)
94#define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt) \
95 TRACE4(mp, XFS_FSTRM_KTRACE_ASSOCIATE, ip, pip, ag, cnt)
96#define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt) \
97 TRACE6(mp, XFS_FSTRM_KTRACE_MOVEAG, ip, pip, oag, ocnt, nag, ncnt)
98#define TRACE_ORPHAN(mp, ip, ag) \
99 TRACE2(mp, XFS_FSTRM_KTRACE_ORPHAN, ip, ag);
100
101
102#else
103#define TRACE_AG_SCAN(mp, ag, ag2)
104#define TRACE_AG_PICK1(mp, max_ag, maxfree)
105#define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag)
106#define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2)
107#define TRACE_FREE(mp, ip, pip, ag, cnt)
108#define TRACE_LOOKUP(mp, ip, pip, ag, cnt)
109#define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt)
110#define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt)
111#define TRACE_ORPHAN(mp, ip, ag)
112#endif
113
114static kmem_zone_t *item_zone;
115
116/*
117 * Structure for associating a file or a directory with an allocation group.
118 * The parent directory pointer is only needed for files, but since there will
119 * generally be vastly more files than directories in the cache, using the same
120 * data structure simplifies the code with very little memory overhead.
121 */
122typedef struct fstrm_item
123{
124 xfs_agnumber_t ag; /* AG currently in use for the file/directory. */
125 xfs_inode_t *ip; /* inode self-pointer. */
126 xfs_inode_t *pip; /* Parent directory inode pointer. */
127} fstrm_item_t;
128
129
130/*
131 * Scan the AGs starting at startag looking for an AG that isn't in use and has
132 * at least minlen blocks free.
133 */
134static int
135_xfs_filestream_pick_ag(
136 xfs_mount_t *mp,
137 xfs_agnumber_t startag,
138 xfs_agnumber_t *agp,
139 int flags,
140 xfs_extlen_t minlen)
141{
142 int err, trylock, nscan;
143 xfs_extlen_t delta, longest, need, free, minfree, maxfree = 0;
144 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
145 struct xfs_perag *pag;
146
147 /* 2% of an AG's blocks must be free for it to be chosen. */
148 minfree = mp->m_sb.sb_agblocks / 50;
149
150 ag = startag;
151 *agp = NULLAGNUMBER;
152
153 /* For the first pass, don't sleep trying to init the per-AG. */
154 trylock = XFS_ALLOC_FLAG_TRYLOCK;
155
156 for (nscan = 0; 1; nscan++) {
157
158 TRACE_AG_SCAN(mp, ag, xfs_filestream_peek_ag(mp, ag));
159
160 pag = mp->m_perag + ag;
161
162 if (!pag->pagf_init) {
163 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
164 if (err && !trylock)
165 return err;
166 }
167
168 /* Might fail sometimes during the 1st pass with trylock set. */
169 if (!pag->pagf_init)
170 goto next_ag;
171
172 /* Keep track of the AG with the most free blocks. */
173 if (pag->pagf_freeblks > maxfree) {
174 maxfree = pag->pagf_freeblks;
175 max_ag = ag;
176 }
177
178 /*
179 * The AG reference count does two things: it enforces mutual
180 * exclusion when examining the suitability of an AG in this
181 * loop, and it guards against two filestreams being established
182 * in the same AG as each other.
183 */
184 if (xfs_filestream_get_ag(mp, ag) > 1) {
185 xfs_filestream_put_ag(mp, ag);
186 goto next_ag;
187 }
188
189 need = XFS_MIN_FREELIST_PAG(pag, mp);
190 delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
191 longest = (pag->pagf_longest > delta) ?
192 (pag->pagf_longest - delta) :
193 (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
194
195 if (((minlen && longest >= minlen) ||
196 (!minlen && pag->pagf_freeblks >= minfree)) &&
197 (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||
198 (flags & XFS_PICK_LOWSPACE))) {
199
200 /* Break out, retaining the reference on the AG. */
201 free = pag->pagf_freeblks;
202 *agp = ag;
203 break;
204 }
205
206 /* Drop the reference on this AG, it's not usable. */
207 xfs_filestream_put_ag(mp, ag);
208next_ag:
209 /* Move to the next AG, wrapping to AG 0 if necessary. */
210 if (++ag >= mp->m_sb.sb_agcount)
211 ag = 0;
212
213 /* If a full pass of the AGs hasn't been done yet, continue. */
214 if (ag != startag)
215 continue;
216
217 /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */
218 if (trylock != 0) {
219 trylock = 0;
220 continue;
221 }
222
223 /* Finally, if lowspace wasn't set, set it for the 3rd pass. */
224 if (!(flags & XFS_PICK_LOWSPACE)) {
225 flags |= XFS_PICK_LOWSPACE;
226 continue;
227 }
228
229 /*
230 * Take the AG with the most free space, regardless of whether
231 * it's already in use by another filestream.
232 */
233 if (max_ag != NULLAGNUMBER) {
234 xfs_filestream_get_ag(mp, max_ag);
235 TRACE_AG_PICK1(mp, max_ag, maxfree);
236 free = maxfree;
237 *agp = max_ag;
238 break;
239 }
240
241 /* take AG 0 if none matched */
242 TRACE_AG_PICK1(mp, max_ag, maxfree);
243 *agp = 0;
244 return 0;
245 }
246
247 TRACE_AG_PICK2(mp, startag, *agp, xfs_filestream_peek_ag(mp, *agp),
248 free, nscan, flags);
249
250 return 0;
251}
252
253/*
254 * Set the allocation group number for a file or a directory, updating inode
255 * references and per-AG references as appropriate. Must be called with the
256 * m_peraglock held in read mode.
257 */
258static int
259_xfs_filestream_update_ag(
260 xfs_inode_t *ip,
261 xfs_inode_t *pip,
262 xfs_agnumber_t ag)
263{
264 int err = 0;
265 xfs_mount_t *mp;
266 xfs_mru_cache_t *cache;
267 fstrm_item_t *item;
268 xfs_agnumber_t old_ag;
269 xfs_inode_t *old_pip;
270
271 /*
272 * Either ip is a regular file and pip is a directory, or ip is a
273 * directory and pip is NULL.
274 */
275 ASSERT(ip && (((ip->i_d.di_mode & S_IFREG) && pip &&
276 (pip->i_d.di_mode & S_IFDIR)) ||
277 ((ip->i_d.di_mode & S_IFDIR) && !pip)));
278
279 mp = ip->i_mount;
280 cache = mp->m_filestream;
281
282 item = xfs_mru_cache_lookup(cache, ip->i_ino);
283 if (item) {
284 ASSERT(item->ip == ip);
285 old_ag = item->ag;
286 item->ag = ag;
287 old_pip = item->pip;
288 item->pip = pip;
289 xfs_mru_cache_done(cache);
290
291 /*
292 * If the AG has changed, drop the old ref and take a new one,
293 * effectively transferring the reference from old to new AG.
294 */
295 if (ag != old_ag) {
296 xfs_filestream_put_ag(mp, old_ag);
297 xfs_filestream_get_ag(mp, ag);
298 }
299
300 /*
301 * If ip is a file and its pip has changed, drop the old ref and
302 * take a new one.
303 */
304 if (pip && pip != old_pip) {
305 IRELE(old_pip);
306 IHOLD(pip);
307 }
308
309 TRACE_UPDATE(mp, ip, old_ag, xfs_filestream_peek_ag(mp, old_ag),
310 ag, xfs_filestream_peek_ag(mp, ag));
311 return 0;
312 }
313
314 item = kmem_zone_zalloc(item_zone, KM_MAYFAIL);
315 if (!item)
316 return ENOMEM;
317
318 item->ag = ag;
319 item->ip = ip;
320 item->pip = pip;
321
322 err = xfs_mru_cache_insert(cache, ip->i_ino, item);
323 if (err) {
324 kmem_zone_free(item_zone, item);
325 return err;
326 }
327
328 /* Take a reference on the AG. */
329 xfs_filestream_get_ag(mp, ag);
330
331 /*
332 * Take a reference on the inode itself regardless of whether it's a
333 * regular file or a directory.
334 */
335 IHOLD(ip);
336
337 /*
338 * In the case of a regular file, take a reference on the parent inode
339 * as well to ensure it remains in-core.
340 */
341 if (pip)
342 IHOLD(pip);
343
344 TRACE_UPDATE(mp, ip, ag, xfs_filestream_peek_ag(mp, ag),
345 ag, xfs_filestream_peek_ag(mp, ag));
346
347 return 0;
348}
349
350/* xfs_fstrm_free_func(): callback for freeing cached stream items. */
351void
352xfs_fstrm_free_func(
353 xfs_ino_t ino,
354 fstrm_item_t *item)
355{
356 xfs_inode_t *ip = item->ip;
357 int ref;
358
359 ASSERT(ip->i_ino == ino);
360
361 xfs_iflags_clear(ip, XFS_IFILESTREAM);
362
363 /* Drop the reference taken on the AG when the item was added. */
364 ref = xfs_filestream_put_ag(ip->i_mount, item->ag);
365
366 ASSERT(ref >= 0);
367 TRACE_FREE(ip->i_mount, ip, item->pip, item->ag,
368 xfs_filestream_peek_ag(ip->i_mount, item->ag));
369
370 /*
371 * _xfs_filestream_update_ag() always takes a reference on the inode
372 * itself, whether it's a file or a directory. Release it here.
373 * This can result in the inode being freed and so we must
374 * not hold any inode locks when freeing filesstreams objects
375 * otherwise we can deadlock here.
376 */
377 IRELE(ip);
378
379 /*
380 * In the case of a regular file, _xfs_filestream_update_ag() also
381 * takes a ref on the parent inode to keep it in-core. Release that
382 * too.
383 */
384 if (item->pip)
385 IRELE(item->pip);
386
387 /* Finally, free the memory allocated for the item. */
388 kmem_zone_free(item_zone, item);
389}
390
391/*
392 * xfs_filestream_init() is called at xfs initialisation time to set up the
393 * memory zone that will be used for filestream data structure allocation.
394 */
395int
396xfs_filestream_init(void)
397{
398 item_zone = kmem_zone_init(sizeof(fstrm_item_t), "fstrm_item");
399#ifdef XFS_FILESTREAMS_TRACE
400 xfs_filestreams_trace_buf = ktrace_alloc(XFS_FSTRM_KTRACE_SIZE, KM_SLEEP);
401#endif
402 return item_zone ? 0 : -ENOMEM;
403}
404
405/*
406 * xfs_filestream_uninit() is called at xfs termination time to destroy the
407 * memory zone that was used for filestream data structure allocation.
408 */
409void
410xfs_filestream_uninit(void)
411{
412#ifdef XFS_FILESTREAMS_TRACE
413 ktrace_free(xfs_filestreams_trace_buf);
414#endif
415 kmem_zone_destroy(item_zone);
416}
417
418/*
419 * xfs_filestream_mount() is called when a file system is mounted with the
420 * filestream option. It is responsible for allocating the data structures
421 * needed to track the new file system's file streams.
422 */
423int
424xfs_filestream_mount(
425 xfs_mount_t *mp)
426{
427 int err;
428 unsigned int lifetime, grp_count;
429
430 /*
431 * The filestream timer tunable is currently fixed within the range of
432 * one second to four minutes, with five seconds being the default. The
433 * group count is somewhat arbitrary, but it'd be nice to adhere to the
434 * timer tunable to within about 10 percent. This requires at least 10
435 * groups.
436 */
437 lifetime = xfs_fstrm_centisecs * 10;
438 grp_count = 10;
439
440 err = xfs_mru_cache_create(&mp->m_filestream, lifetime, grp_count,
441 (xfs_mru_cache_free_func_t)xfs_fstrm_free_func);
442
443 return err;
444}
445
446/*
447 * xfs_filestream_unmount() is called when a file system that was mounted with
448 * the filestream option is unmounted. It drains the data structures created
449 * to track the file system's file streams and frees all the memory that was
450 * allocated.
451 */
452void
453xfs_filestream_unmount(
454 xfs_mount_t *mp)
455{
456 xfs_mru_cache_destroy(mp->m_filestream);
457}
458
459/*
460 * If the mount point's m_perag array is going to be reallocated, all
461 * outstanding cache entries must be flushed to avoid accessing reference count
462 * addresses that have been freed. The call to xfs_filestream_flush() must be
463 * made inside the block that holds the m_peraglock in write mode to do the
464 * reallocation.
465 */
466void
467xfs_filestream_flush(
468 xfs_mount_t *mp)
469{
470 /* point in time flush, so keep the reaper running */
471 xfs_mru_cache_flush(mp->m_filestream, 1);
472}
473
474/*
475 * Return the AG of the filestream the file or directory belongs to, or
476 * NULLAGNUMBER otherwise.
477 */
478xfs_agnumber_t
479xfs_filestream_lookup_ag(
480 xfs_inode_t *ip)
481{
482 xfs_mru_cache_t *cache;
483 fstrm_item_t *item;
484 xfs_agnumber_t ag;
485 int ref;
486
487 if (!(ip->i_d.di_mode & (S_IFREG | S_IFDIR))) {
488 ASSERT(0);
489 return NULLAGNUMBER;
490 }
491
492 cache = ip->i_mount->m_filestream;
493 item = xfs_mru_cache_lookup(cache, ip->i_ino);
494 if (!item) {
495 TRACE_LOOKUP(ip->i_mount, ip, NULL, NULLAGNUMBER, 0);
496 return NULLAGNUMBER;
497 }
498
499 ASSERT(ip == item->ip);
500 ag = item->ag;
501 ref = xfs_filestream_peek_ag(ip->i_mount, ag);
502 xfs_mru_cache_done(cache);
503
504 TRACE_LOOKUP(ip->i_mount, ip, item->pip, ag, ref);
505 return ag;
506}
507
508/*
509 * xfs_filestream_associate() should only be called to associate a regular file
510 * with its parent directory. Calling it with a child directory isn't
511 * appropriate because filestreams don't apply to entire directory hierarchies.
512 * Creating a file in a child directory of an existing filestream directory
513 * starts a new filestream with its own allocation group association.
514 *
515 * Returns < 0 on error, 0 if successful association occurred, > 0 if
516 * we failed to get an association because of locking issues.
517 */
518int
519xfs_filestream_associate(
520 xfs_inode_t *pip,
521 xfs_inode_t *ip)
522{
523 xfs_mount_t *mp;
524 xfs_mru_cache_t *cache;
525 fstrm_item_t *item;
526 xfs_agnumber_t ag, rotorstep, startag;
527 int err = 0;
528
529 ASSERT(pip->i_d.di_mode & S_IFDIR);
530 ASSERT(ip->i_d.di_mode & S_IFREG);
531 if (!(pip->i_d.di_mode & S_IFDIR) || !(ip->i_d.di_mode & S_IFREG))
532 return -EINVAL;
533
534 mp = pip->i_mount;
535 cache = mp->m_filestream;
536 down_read(&mp->m_peraglock);
537
538 /*
539 * We have a problem, Houston.
540 *
541 * Taking the iolock here violates inode locking order - we already
542 * hold the ilock. Hence if we block getting this lock we may never
543 * wake. Unfortunately, that means if we can't get the lock, we're
544 * screwed in terms of getting a stream association - we can't spin
545 * waiting for the lock because someone else is waiting on the lock we
546 * hold and we cannot drop that as we are in a transaction here.
547 *
548 * Lucky for us, this inversion is rarely a problem because it's a
549 * directory inode that we are trying to lock here and that means the
550 * only place that matters is xfs_sync_inodes() and SYNC_DELWRI is
551 * used. i.e. freeze, remount-ro, quotasync or unmount.
552 *
553 * So, if we can't get the iolock without sleeping then just give up
554 */
555 if (!xfs_ilock_nowait(pip, XFS_IOLOCK_EXCL)) {
556 up_read(&mp->m_peraglock);
557 return 1;
558 }
559
560 /* If the parent directory is already in the cache, use its AG. */
561 item = xfs_mru_cache_lookup(cache, pip->i_ino);
562 if (item) {
563 ASSERT(item->ip == pip);
564 ag = item->ag;
565 xfs_mru_cache_done(cache);
566
567 TRACE_LOOKUP(mp, pip, pip, ag, xfs_filestream_peek_ag(mp, ag));
568 err = _xfs_filestream_update_ag(ip, pip, ag);
569
570 goto exit;
571 }
572
573 /*
574 * Set the starting AG using the rotor for inode32, otherwise
575 * use the directory inode's AG.
576 */
577 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
578 rotorstep = xfs_rotorstep;
579 startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
580 mp->m_agfrotor = (mp->m_agfrotor + 1) %
581 (mp->m_sb.sb_agcount * rotorstep);
582 } else
583 startag = XFS_INO_TO_AGNO(mp, pip->i_ino);
584
585 /* Pick a new AG for the parent inode starting at startag. */
586 err = _xfs_filestream_pick_ag(mp, startag, &ag, 0, 0);
587 if (err || ag == NULLAGNUMBER)
588 goto exit_did_pick;
589
590 /* Associate the parent inode with the AG. */
591 err = _xfs_filestream_update_ag(pip, NULL, ag);
592 if (err)
593 goto exit_did_pick;
594
595 /* Associate the file inode with the AG. */
596 err = _xfs_filestream_update_ag(ip, pip, ag);
597 if (err)
598 goto exit_did_pick;
599
600 TRACE_ASSOCIATE(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag));
601
602exit_did_pick:
603 /*
604 * If _xfs_filestream_pick_ag() returned a valid AG, remove the
605 * reference it took on it, since the file and directory will have taken
606 * their own now if they were successfully cached.
607 */
608 if (ag != NULLAGNUMBER)
609 xfs_filestream_put_ag(mp, ag);
610
611exit:
612 xfs_iunlock(pip, XFS_IOLOCK_EXCL);
613 up_read(&mp->m_peraglock);
614 return -err;
615}
616
617/*
618 * Pick a new allocation group for the current file and its file stream. This
619 * function is called by xfs_bmap_filestreams() with the mount point's per-ag
620 * lock held.
621 */
622int
623xfs_filestream_new_ag(
624 xfs_bmalloca_t *ap,
625 xfs_agnumber_t *agp)
626{
627 int flags, err;
628 xfs_inode_t *ip, *pip = NULL;
629 xfs_mount_t *mp;
630 xfs_mru_cache_t *cache;
631 xfs_extlen_t minlen;
632 fstrm_item_t *dir, *file;
633 xfs_agnumber_t ag = NULLAGNUMBER;
634
635 ip = ap->ip;
636 mp = ip->i_mount;
637 cache = mp->m_filestream;
638 minlen = ap->alen;
639 *agp = NULLAGNUMBER;
640
641 /*
642 * Look for the file in the cache, removing it if it's found. Doing
643 * this allows it to be held across the dir lookup that follows.
644 */
645 file = xfs_mru_cache_remove(cache, ip->i_ino);
646 if (file) {
647 ASSERT(ip == file->ip);
648
649 /* Save the file's parent inode and old AG number for later. */
650 pip = file->pip;
651 ag = file->ag;
652
653 /* Look for the file's directory in the cache. */
654 dir = xfs_mru_cache_lookup(cache, pip->i_ino);
655 if (dir) {
656 ASSERT(pip == dir->ip);
657
658 /*
659 * If the directory has already moved on to a new AG,
660 * use that AG as the new AG for the file. Don't
661 * forget to twiddle the AG refcounts to match the
662 * movement.
663 */
664 if (dir->ag != file->ag) {
665 xfs_filestream_put_ag(mp, file->ag);
666 xfs_filestream_get_ag(mp, dir->ag);
667 *agp = file->ag = dir->ag;
668 }
669
670 xfs_mru_cache_done(cache);
671 }
672
673 /*
674 * Put the file back in the cache. If this fails, the free
675 * function needs to be called to tidy up in the same way as if
676 * the item had simply expired from the cache.
677 */
678 err = xfs_mru_cache_insert(cache, ip->i_ino, file);
679 if (err) {
680 xfs_fstrm_free_func(ip->i_ino, file);
681 return err;
682 }
683
684 /*
685 * If the file's AG was moved to the directory's new AG, there's
686 * nothing more to be done.
687 */
688 if (*agp != NULLAGNUMBER) {
689 TRACE_MOVEAG(mp, ip, pip,
690 ag, xfs_filestream_peek_ag(mp, ag),
691 *agp, xfs_filestream_peek_ag(mp, *agp));
692 return 0;
693 }
694 }
695
696 /*
697 * If the file's parent directory is known, take its iolock in exclusive
698 * mode to prevent two sibling files from racing each other to migrate
699 * themselves and their parent to different AGs.
700 */
701 if (pip)
702 xfs_ilock(pip, XFS_IOLOCK_EXCL);
703
704 /*
705 * A new AG needs to be found for the file. If the file's parent
706 * directory is also known, it will be moved to the new AG as well to
707 * ensure that files created inside it in future use the new AG.
708 */
709 ag = (ag == NULLAGNUMBER) ? 0 : (ag + 1) % mp->m_sb.sb_agcount;
710 flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
711 (ap->low ? XFS_PICK_LOWSPACE : 0);
712
713 err = _xfs_filestream_pick_ag(mp, ag, agp, flags, minlen);
714 if (err || *agp == NULLAGNUMBER)
715 goto exit;
716
717 /*
718 * If the file wasn't found in the file cache, then its parent directory
719 * inode isn't known. For this to have happened, the file must either
720 * be pre-existing, or it was created long enough ago that its cache
721 * entry has expired. This isn't the sort of usage that the filestreams
722 * allocator is trying to optimise, so there's no point trying to track
723 * its new AG somehow in the filestream data structures.
724 */
725 if (!pip) {
726 TRACE_ORPHAN(mp, ip, *agp);
727 goto exit;
728 }
729
730 /* Associate the parent inode with the AG. */
731 err = _xfs_filestream_update_ag(pip, NULL, *agp);
732 if (err)
733 goto exit;
734
735 /* Associate the file inode with the AG. */
736 err = _xfs_filestream_update_ag(ip, pip, *agp);
737 if (err)
738 goto exit;
739
740 TRACE_MOVEAG(mp, ip, pip, NULLAGNUMBER, 0,
741 *agp, xfs_filestream_peek_ag(mp, *agp));
742
743exit:
744 /*
745 * If _xfs_filestream_pick_ag() returned a valid AG, remove the
746 * reference it took on it, since the file and directory will have taken
747 * their own now if they were successfully cached.
748 */
749 if (*agp != NULLAGNUMBER)
750 xfs_filestream_put_ag(mp, *agp);
751 else
752 *agp = 0;
753
754 if (pip)
755 xfs_iunlock(pip, XFS_IOLOCK_EXCL);
756
757 return err;
758}
759
760/*
761 * Remove an association between an inode and a filestream object.
762 * Typically this is done on last close of an unlinked file.
763 */
764void
765xfs_filestream_deassociate(
766 xfs_inode_t *ip)
767{
768 xfs_mru_cache_t *cache = ip->i_mount->m_filestream;
769
770 xfs_mru_cache_delete(cache, ip->i_ino);
771}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-20 12:52:29 -0500