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2a82b8be DC |
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" | |
2a82b8be DC |
21 | #include "xfs_dinode.h" |
22 | #include "xfs_inode.h" | |
23 | #include "xfs_ag.h" | |
2a82b8be DC |
24 | #include "xfs_log.h" |
25 | #include "xfs_trans.h" | |
26 | #include "xfs_sb.h" | |
27 | #include "xfs_mount.h" | |
28 | #include "xfs_bmap.h" | |
29 | #include "xfs_alloc.h" | |
30 | #include "xfs_utils.h" | |
31 | #include "xfs_mru_cache.h" | |
32 | #include "xfs_filestream.h" | |
0b1b213f | 33 | #include "xfs_trace.h" |
2a82b8be DC |
34 | |
35 | #ifdef XFS_FILESTREAMS_TRACE | |
36 | ||
37 | ktrace_t *xfs_filestreams_trace_buf; | |
38 | ||
39 | STATIC void | |
40 | xfs_filestreams_trace( | |
41 | xfs_mount_t *mp, /* mount point */ | |
42 | int type, /* type of trace */ | |
43 | const char *func, /* source function */ | |
44 | int line, /* source line number */ | |
45 | __psunsigned_t arg0, | |
46 | __psunsigned_t arg1, | |
47 | __psunsigned_t arg2, | |
48 | __psunsigned_t arg3, | |
49 | __psunsigned_t arg4, | |
50 | __psunsigned_t arg5) | |
51 | { | |
52 | ktrace_enter(xfs_filestreams_trace_buf, | |
53 | (void *)(__psint_t)(type | (line << 16)), | |
54 | (void *)func, | |
55 | (void *)(__psunsigned_t)current_pid(), | |
56 | (void *)mp, | |
57 | (void *)(__psunsigned_t)arg0, | |
58 | (void *)(__psunsigned_t)arg1, | |
59 | (void *)(__psunsigned_t)arg2, | |
60 | (void *)(__psunsigned_t)arg3, | |
61 | (void *)(__psunsigned_t)arg4, | |
62 | (void *)(__psunsigned_t)arg5, | |
63 | NULL, NULL, NULL, NULL, NULL, NULL); | |
64 | } | |
65 | ||
66 | #define TRACE0(mp,t) TRACE6(mp,t,0,0,0,0,0,0) | |
67 | #define TRACE1(mp,t,a0) TRACE6(mp,t,a0,0,0,0,0,0) | |
68 | #define TRACE2(mp,t,a0,a1) TRACE6(mp,t,a0,a1,0,0,0,0) | |
69 | #define TRACE3(mp,t,a0,a1,a2) TRACE6(mp,t,a0,a1,a2,0,0,0) | |
70 | #define TRACE4(mp,t,a0,a1,a2,a3) TRACE6(mp,t,a0,a1,a2,a3,0,0) | |
71 | #define TRACE5(mp,t,a0,a1,a2,a3,a4) TRACE6(mp,t,a0,a1,a2,a3,a4,0) | |
72 | #define TRACE6(mp,t,a0,a1,a2,a3,a4,a5) \ | |
34a622b2 | 73 | xfs_filestreams_trace(mp, t, __func__, __LINE__, \ |
2a82b8be DC |
74 | (__psunsigned_t)a0, (__psunsigned_t)a1, \ |
75 | (__psunsigned_t)a2, (__psunsigned_t)a3, \ | |
76 | (__psunsigned_t)a4, (__psunsigned_t)a5) | |
77 | ||
78 | #define TRACE_AG_SCAN(mp, ag, ag2) \ | |
79 | TRACE2(mp, XFS_FSTRM_KTRACE_AGSCAN, ag, ag2); | |
80 | #define TRACE_AG_PICK1(mp, max_ag, maxfree) \ | |
81 | TRACE2(mp, XFS_FSTRM_KTRACE_AGPICK1, max_ag, maxfree); | |
82 | #define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag) \ | |
83 | TRACE6(mp, XFS_FSTRM_KTRACE_AGPICK2, ag, ag2, \ | |
84 | cnt, free, scan, flag) | |
85 | #define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2) \ | |
86 | TRACE5(mp, XFS_FSTRM_KTRACE_UPDATE, ip, ag, cnt, ag2, cnt2) | |
87 | #define TRACE_FREE(mp, ip, pip, ag, cnt) \ | |
88 | TRACE4(mp, XFS_FSTRM_KTRACE_FREE, ip, pip, ag, cnt) | |
89 | #define TRACE_LOOKUP(mp, ip, pip, ag, cnt) \ | |
90 | TRACE4(mp, XFS_FSTRM_KTRACE_ITEM_LOOKUP, ip, pip, ag, cnt) | |
91 | #define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt) \ | |
92 | TRACE4(mp, XFS_FSTRM_KTRACE_ASSOCIATE, ip, pip, ag, cnt) | |
93 | #define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt) \ | |
94 | TRACE6(mp, XFS_FSTRM_KTRACE_MOVEAG, ip, pip, oag, ocnt, nag, ncnt) | |
95 | #define TRACE_ORPHAN(mp, ip, ag) \ | |
96 | TRACE2(mp, XFS_FSTRM_KTRACE_ORPHAN, ip, ag); | |
97 | ||
98 | ||
99 | #else | |
100 | #define TRACE_AG_SCAN(mp, ag, ag2) | |
101 | #define TRACE_AG_PICK1(mp, max_ag, maxfree) | |
102 | #define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag) | |
103 | #define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2) | |
104 | #define TRACE_FREE(mp, ip, pip, ag, cnt) | |
105 | #define TRACE_LOOKUP(mp, ip, pip, ag, cnt) | |
106 | #define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt) | |
107 | #define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt) | |
108 | #define TRACE_ORPHAN(mp, ip, ag) | |
109 | #endif | |
110 | ||
111 | static kmem_zone_t *item_zone; | |
112 | ||
113 | /* | |
114 | * Structure for associating a file or a directory with an allocation group. | |
115 | * The parent directory pointer is only needed for files, but since there will | |
116 | * generally be vastly more files than directories in the cache, using the same | |
117 | * data structure simplifies the code with very little memory overhead. | |
118 | */ | |
119 | typedef struct fstrm_item | |
120 | { | |
121 | xfs_agnumber_t ag; /* AG currently in use for the file/directory. */ | |
122 | xfs_inode_t *ip; /* inode self-pointer. */ | |
123 | xfs_inode_t *pip; /* Parent directory inode pointer. */ | |
124 | } fstrm_item_t; | |
125 | ||
0664ce8d CH |
126 | /* |
127 | * Allocation group filestream associations are tracked with per-ag atomic | |
128 | * counters. These counters allow _xfs_filestream_pick_ag() to tell whether a | |
129 | * particular AG already has active filestreams associated with it. The mount | |
130 | * point's m_peraglock is used to protect these counters from per-ag array | |
131 | * re-allocation during a growfs operation. When xfs_growfs_data_private() is | |
132 | * about to reallocate the array, it calls xfs_filestream_flush() with the | |
133 | * m_peraglock held in write mode. | |
134 | * | |
135 | * Since xfs_mru_cache_flush() guarantees that all the free functions for all | |
136 | * the cache elements have finished executing before it returns, it's safe for | |
137 | * the free functions to use the atomic counters without m_peraglock protection. | |
138 | * This allows the implementation of xfs_fstrm_free_func() to be agnostic about | |
139 | * whether it was called with the m_peraglock held in read mode, write mode or | |
140 | * not held at all. The race condition this addresses is the following: | |
141 | * | |
142 | * - The work queue scheduler fires and pulls a filestream directory cache | |
143 | * element off the LRU end of the cache for deletion, then gets pre-empted. | |
144 | * - A growfs operation grabs the m_peraglock in write mode, flushes all the | |
145 | * remaining items from the cache and reallocates the mount point's per-ag | |
146 | * array, resetting all the counters to zero. | |
147 | * - The work queue thread resumes and calls the free function for the element | |
148 | * it started cleaning up earlier. In the process it decrements the | |
149 | * filestreams counter for an AG that now has no references. | |
150 | * | |
151 | * With a shrinkfs feature, the above scenario could panic the system. | |
152 | * | |
153 | * All other uses of the following macros should be protected by either the | |
154 | * m_peraglock held in read mode, or the cache's internal locking exposed by the | |
155 | * interval between a call to xfs_mru_cache_lookup() and a call to | |
156 | * xfs_mru_cache_done(). In addition, the m_peraglock must be held in read mode | |
157 | * when new elements are added to the cache. | |
158 | * | |
159 | * Combined, these locking rules ensure that no associations will ever exist in | |
160 | * the cache that reference per-ag array elements that have since been | |
161 | * reallocated. | |
162 | */ | |
163 | static int | |
164 | xfs_filestream_peek_ag( | |
165 | xfs_mount_t *mp, | |
166 | xfs_agnumber_t agno) | |
167 | { | |
168 | struct xfs_perag *pag; | |
169 | int ret; | |
170 | ||
171 | pag = xfs_perag_get(mp, agno); | |
172 | ret = atomic_read(&pag->pagf_fstrms); | |
173 | xfs_perag_put(pag); | |
174 | return ret; | |
175 | } | |
176 | ||
177 | static int | |
178 | xfs_filestream_get_ag( | |
179 | xfs_mount_t *mp, | |
180 | xfs_agnumber_t agno) | |
181 | { | |
182 | struct xfs_perag *pag; | |
183 | int ret; | |
184 | ||
185 | pag = xfs_perag_get(mp, agno); | |
186 | ret = atomic_inc_return(&pag->pagf_fstrms); | |
187 | xfs_perag_put(pag); | |
188 | return ret; | |
189 | } | |
190 | ||
191 | static void | |
192 | xfs_filestream_put_ag( | |
193 | xfs_mount_t *mp, | |
194 | xfs_agnumber_t agno) | |
195 | { | |
196 | struct xfs_perag *pag; | |
197 | ||
198 | pag = xfs_perag_get(mp, agno); | |
199 | atomic_dec(&pag->pagf_fstrms); | |
200 | xfs_perag_put(pag); | |
201 | } | |
2a82b8be DC |
202 | |
203 | /* | |
204 | * Scan the AGs starting at startag looking for an AG that isn't in use and has | |
205 | * at least minlen blocks free. | |
206 | */ | |
207 | static int | |
208 | _xfs_filestream_pick_ag( | |
209 | xfs_mount_t *mp, | |
210 | xfs_agnumber_t startag, | |
211 | xfs_agnumber_t *agp, | |
212 | int flags, | |
213 | xfs_extlen_t minlen) | |
214 | { | |
4196ac08 | 215 | int streams, max_streams; |
2a82b8be | 216 | int err, trylock, nscan; |
6cc87645 | 217 | xfs_extlen_t longest, free, minfree, maxfree = 0; |
2a82b8be DC |
218 | xfs_agnumber_t ag, max_ag = NULLAGNUMBER; |
219 | struct xfs_perag *pag; | |
220 | ||
221 | /* 2% of an AG's blocks must be free for it to be chosen. */ | |
222 | minfree = mp->m_sb.sb_agblocks / 50; | |
223 | ||
224 | ag = startag; | |
225 | *agp = NULLAGNUMBER; | |
226 | ||
227 | /* For the first pass, don't sleep trying to init the per-AG. */ | |
228 | trylock = XFS_ALLOC_FLAG_TRYLOCK; | |
229 | ||
230 | for (nscan = 0; 1; nscan++) { | |
4196ac08 DC |
231 | pag = xfs_perag_get(mp, ag); |
232 | TRACE_AG_SCAN(mp, ag, atomic_read(&pag->pagf_fstrms)); | |
2a82b8be DC |
233 | |
234 | if (!pag->pagf_init) { | |
235 | err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); | |
4196ac08 DC |
236 | if (err && !trylock) { |
237 | xfs_perag_put(pag); | |
2a82b8be | 238 | return err; |
4196ac08 | 239 | } |
2a82b8be DC |
240 | } |
241 | ||
242 | /* Might fail sometimes during the 1st pass with trylock set. */ | |
243 | if (!pag->pagf_init) | |
244 | goto next_ag; | |
245 | ||
246 | /* Keep track of the AG with the most free blocks. */ | |
247 | if (pag->pagf_freeblks > maxfree) { | |
248 | maxfree = pag->pagf_freeblks; | |
4196ac08 | 249 | max_streams = atomic_read(&pag->pagf_fstrms); |
2a82b8be DC |
250 | max_ag = ag; |
251 | } | |
252 | ||
253 | /* | |
254 | * The AG reference count does two things: it enforces mutual | |
255 | * exclusion when examining the suitability of an AG in this | |
256 | * loop, and it guards against two filestreams being established | |
257 | * in the same AG as each other. | |
258 | */ | |
259 | if (xfs_filestream_get_ag(mp, ag) > 1) { | |
260 | xfs_filestream_put_ag(mp, ag); | |
261 | goto next_ag; | |
262 | } | |
263 | ||
6cc87645 | 264 | longest = xfs_alloc_longest_free_extent(mp, pag); |
2a82b8be DC |
265 | if (((minlen && longest >= minlen) || |
266 | (!minlen && pag->pagf_freeblks >= minfree)) && | |
267 | (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) || | |
268 | (flags & XFS_PICK_LOWSPACE))) { | |
269 | ||
270 | /* Break out, retaining the reference on the AG. */ | |
271 | free = pag->pagf_freeblks; | |
4196ac08 DC |
272 | streams = atomic_read(&pag->pagf_fstrms); |
273 | xfs_perag_put(pag); | |
2a82b8be DC |
274 | *agp = ag; |
275 | break; | |
276 | } | |
277 | ||
278 | /* Drop the reference on this AG, it's not usable. */ | |
279 | xfs_filestream_put_ag(mp, ag); | |
280 | next_ag: | |
4196ac08 | 281 | xfs_perag_put(pag); |
2a82b8be DC |
282 | /* Move to the next AG, wrapping to AG 0 if necessary. */ |
283 | if (++ag >= mp->m_sb.sb_agcount) | |
284 | ag = 0; | |
285 | ||
286 | /* If a full pass of the AGs hasn't been done yet, continue. */ | |
287 | if (ag != startag) | |
288 | continue; | |
289 | ||
290 | /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */ | |
291 | if (trylock != 0) { | |
292 | trylock = 0; | |
293 | continue; | |
294 | } | |
295 | ||
296 | /* Finally, if lowspace wasn't set, set it for the 3rd pass. */ | |
297 | if (!(flags & XFS_PICK_LOWSPACE)) { | |
298 | flags |= XFS_PICK_LOWSPACE; | |
299 | continue; | |
300 | } | |
301 | ||
302 | /* | |
303 | * Take the AG with the most free space, regardless of whether | |
304 | * it's already in use by another filestream. | |
305 | */ | |
306 | if (max_ag != NULLAGNUMBER) { | |
307 | xfs_filestream_get_ag(mp, max_ag); | |
308 | TRACE_AG_PICK1(mp, max_ag, maxfree); | |
4196ac08 | 309 | streams = max_streams; |
2a82b8be DC |
310 | free = maxfree; |
311 | *agp = max_ag; | |
312 | break; | |
313 | } | |
314 | ||
315 | /* take AG 0 if none matched */ | |
316 | TRACE_AG_PICK1(mp, max_ag, maxfree); | |
317 | *agp = 0; | |
318 | return 0; | |
319 | } | |
320 | ||
4196ac08 | 321 | TRACE_AG_PICK2(mp, startag, *agp, streams, free, nscan, flags); |
2a82b8be DC |
322 | |
323 | return 0; | |
324 | } | |
325 | ||
326 | /* | |
327 | * Set the allocation group number for a file or a directory, updating inode | |
1c1c6ebc | 328 | * references and per-AG references as appropriate. |
2a82b8be DC |
329 | */ |
330 | static int | |
331 | _xfs_filestream_update_ag( | |
332 | xfs_inode_t *ip, | |
333 | xfs_inode_t *pip, | |
334 | xfs_agnumber_t ag) | |
335 | { | |
336 | int err = 0; | |
337 | xfs_mount_t *mp; | |
338 | xfs_mru_cache_t *cache; | |
339 | fstrm_item_t *item; | |
340 | xfs_agnumber_t old_ag; | |
341 | xfs_inode_t *old_pip; | |
342 | ||
343 | /* | |
344 | * Either ip is a regular file and pip is a directory, or ip is a | |
345 | * directory and pip is NULL. | |
346 | */ | |
abbede1b | 347 | ASSERT(ip && ((S_ISREG(ip->i_d.di_mode) && pip && |
03209378 AV |
348 | S_ISDIR(pip->i_d.di_mode)) || |
349 | (S_ISDIR(ip->i_d.di_mode) && !pip))); | |
2a82b8be DC |
350 | |
351 | mp = ip->i_mount; | |
352 | cache = mp->m_filestream; | |
353 | ||
354 | item = xfs_mru_cache_lookup(cache, ip->i_ino); | |
355 | if (item) { | |
356 | ASSERT(item->ip == ip); | |
357 | old_ag = item->ag; | |
358 | item->ag = ag; | |
359 | old_pip = item->pip; | |
360 | item->pip = pip; | |
361 | xfs_mru_cache_done(cache); | |
362 | ||
363 | /* | |
364 | * If the AG has changed, drop the old ref and take a new one, | |
365 | * effectively transferring the reference from old to new AG. | |
366 | */ | |
367 | if (ag != old_ag) { | |
368 | xfs_filestream_put_ag(mp, old_ag); | |
369 | xfs_filestream_get_ag(mp, ag); | |
370 | } | |
371 | ||
372 | /* | |
373 | * If ip is a file and its pip has changed, drop the old ref and | |
374 | * take a new one. | |
375 | */ | |
376 | if (pip && pip != old_pip) { | |
377 | IRELE(old_pip); | |
378 | IHOLD(pip); | |
379 | } | |
380 | ||
381 | TRACE_UPDATE(mp, ip, old_ag, xfs_filestream_peek_ag(mp, old_ag), | |
382 | ag, xfs_filestream_peek_ag(mp, ag)); | |
383 | return 0; | |
384 | } | |
385 | ||
386 | item = kmem_zone_zalloc(item_zone, KM_MAYFAIL); | |
387 | if (!item) | |
388 | return ENOMEM; | |
389 | ||
390 | item->ag = ag; | |
391 | item->ip = ip; | |
392 | item->pip = pip; | |
393 | ||
394 | err = xfs_mru_cache_insert(cache, ip->i_ino, item); | |
395 | if (err) { | |
396 | kmem_zone_free(item_zone, item); | |
397 | return err; | |
398 | } | |
399 | ||
400 | /* Take a reference on the AG. */ | |
401 | xfs_filestream_get_ag(mp, ag); | |
402 | ||
403 | /* | |
404 | * Take a reference on the inode itself regardless of whether it's a | |
405 | * regular file or a directory. | |
406 | */ | |
407 | IHOLD(ip); | |
408 | ||
409 | /* | |
410 | * In the case of a regular file, take a reference on the parent inode | |
411 | * as well to ensure it remains in-core. | |
412 | */ | |
413 | if (pip) | |
414 | IHOLD(pip); | |
415 | ||
416 | TRACE_UPDATE(mp, ip, ag, xfs_filestream_peek_ag(mp, ag), | |
417 | ag, xfs_filestream_peek_ag(mp, ag)); | |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
422 | /* xfs_fstrm_free_func(): callback for freeing cached stream items. */ | |
a8272ce0 | 423 | STATIC void |
2a82b8be | 424 | xfs_fstrm_free_func( |
bcc7b445 ES |
425 | unsigned long ino, |
426 | void *data) | |
2a82b8be | 427 | { |
bcc7b445 | 428 | fstrm_item_t *item = (fstrm_item_t *)data; |
2a82b8be | 429 | xfs_inode_t *ip = item->ip; |
2a82b8be DC |
430 | |
431 | ASSERT(ip->i_ino == ino); | |
432 | ||
433 | xfs_iflags_clear(ip, XFS_IFILESTREAM); | |
434 | ||
435 | /* Drop the reference taken on the AG when the item was added. */ | |
0664ce8d | 436 | xfs_filestream_put_ag(ip->i_mount, item->ag); |
2a82b8be | 437 | |
2a82b8be DC |
438 | TRACE_FREE(ip->i_mount, ip, item->pip, item->ag, |
439 | xfs_filestream_peek_ag(ip->i_mount, item->ag)); | |
440 | ||
441 | /* | |
442 | * _xfs_filestream_update_ag() always takes a reference on the inode | |
443 | * itself, whether it's a file or a directory. Release it here. | |
444 | * This can result in the inode being freed and so we must | |
445 | * not hold any inode locks when freeing filesstreams objects | |
446 | * otherwise we can deadlock here. | |
447 | */ | |
448 | IRELE(ip); | |
449 | ||
450 | /* | |
451 | * In the case of a regular file, _xfs_filestream_update_ag() also | |
452 | * takes a ref on the parent inode to keep it in-core. Release that | |
453 | * too. | |
454 | */ | |
455 | if (item->pip) | |
456 | IRELE(item->pip); | |
457 | ||
458 | /* Finally, free the memory allocated for the item. */ | |
459 | kmem_zone_free(item_zone, item); | |
460 | } | |
461 | ||
462 | /* | |
463 | * xfs_filestream_init() is called at xfs initialisation time to set up the | |
464 | * memory zone that will be used for filestream data structure allocation. | |
465 | */ | |
466 | int | |
467 | xfs_filestream_init(void) | |
468 | { | |
469 | item_zone = kmem_zone_init(sizeof(fstrm_item_t), "fstrm_item"); | |
9f8868ff CH |
470 | if (!item_zone) |
471 | return -ENOMEM; | |
0b1b213f | 472 | |
9f8868ff | 473 | return 0; |
2a82b8be DC |
474 | } |
475 | ||
476 | /* | |
477 | * xfs_filestream_uninit() is called at xfs termination time to destroy the | |
478 | * memory zone that was used for filestream data structure allocation. | |
479 | */ | |
480 | void | |
481 | xfs_filestream_uninit(void) | |
482 | { | |
2a82b8be DC |
483 | kmem_zone_destroy(item_zone); |
484 | } | |
485 | ||
486 | /* | |
487 | * xfs_filestream_mount() is called when a file system is mounted with the | |
488 | * filestream option. It is responsible for allocating the data structures | |
489 | * needed to track the new file system's file streams. | |
490 | */ | |
491 | int | |
492 | xfs_filestream_mount( | |
493 | xfs_mount_t *mp) | |
494 | { | |
495 | int err; | |
496 | unsigned int lifetime, grp_count; | |
497 | ||
498 | /* | |
499 | * The filestream timer tunable is currently fixed within the range of | |
500 | * one second to four minutes, with five seconds being the default. The | |
501 | * group count is somewhat arbitrary, but it'd be nice to adhere to the | |
502 | * timer tunable to within about 10 percent. This requires at least 10 | |
503 | * groups. | |
504 | */ | |
505 | lifetime = xfs_fstrm_centisecs * 10; | |
506 | grp_count = 10; | |
507 | ||
508 | err = xfs_mru_cache_create(&mp->m_filestream, lifetime, grp_count, | |
bcc7b445 | 509 | xfs_fstrm_free_func); |
2a82b8be DC |
510 | |
511 | return err; | |
512 | } | |
513 | ||
514 | /* | |
515 | * xfs_filestream_unmount() is called when a file system that was mounted with | |
516 | * the filestream option is unmounted. It drains the data structures created | |
517 | * to track the file system's file streams and frees all the memory that was | |
518 | * allocated. | |
519 | */ | |
520 | void | |
521 | xfs_filestream_unmount( | |
522 | xfs_mount_t *mp) | |
523 | { | |
524 | xfs_mru_cache_destroy(mp->m_filestream); | |
525 | } | |
526 | ||
2a82b8be DC |
527 | /* |
528 | * Return the AG of the filestream the file or directory belongs to, or | |
529 | * NULLAGNUMBER otherwise. | |
530 | */ | |
531 | xfs_agnumber_t | |
532 | xfs_filestream_lookup_ag( | |
533 | xfs_inode_t *ip) | |
534 | { | |
535 | xfs_mru_cache_t *cache; | |
536 | fstrm_item_t *item; | |
537 | xfs_agnumber_t ag; | |
538 | int ref; | |
539 | ||
03209378 | 540 | if (!S_ISREG(ip->i_d.di_mode) && !S_ISDIR(ip->i_d.di_mode)) { |
2a82b8be DC |
541 | ASSERT(0); |
542 | return NULLAGNUMBER; | |
543 | } | |
544 | ||
545 | cache = ip->i_mount->m_filestream; | |
546 | item = xfs_mru_cache_lookup(cache, ip->i_ino); | |
547 | if (!item) { | |
548 | TRACE_LOOKUP(ip->i_mount, ip, NULL, NULLAGNUMBER, 0); | |
549 | return NULLAGNUMBER; | |
550 | } | |
551 | ||
552 | ASSERT(ip == item->ip); | |
553 | ag = item->ag; | |
554 | ref = xfs_filestream_peek_ag(ip->i_mount, ag); | |
555 | xfs_mru_cache_done(cache); | |
556 | ||
557 | TRACE_LOOKUP(ip->i_mount, ip, item->pip, ag, ref); | |
558 | return ag; | |
559 | } | |
560 | ||
561 | /* | |
562 | * xfs_filestream_associate() should only be called to associate a regular file | |
563 | * with its parent directory. Calling it with a child directory isn't | |
564 | * appropriate because filestreams don't apply to entire directory hierarchies. | |
565 | * Creating a file in a child directory of an existing filestream directory | |
566 | * starts a new filestream with its own allocation group association. | |
567 | * | |
568 | * Returns < 0 on error, 0 if successful association occurred, > 0 if | |
569 | * we failed to get an association because of locking issues. | |
570 | */ | |
571 | int | |
572 | xfs_filestream_associate( | |
573 | xfs_inode_t *pip, | |
574 | xfs_inode_t *ip) | |
575 | { | |
576 | xfs_mount_t *mp; | |
577 | xfs_mru_cache_t *cache; | |
578 | fstrm_item_t *item; | |
579 | xfs_agnumber_t ag, rotorstep, startag; | |
580 | int err = 0; | |
581 | ||
03209378 AV |
582 | ASSERT(S_ISDIR(pip->i_d.di_mode)); |
583 | ASSERT(S_ISREG(ip->i_d.di_mode)); | |
584 | if (!S_ISDIR(pip->i_d.di_mode) || !S_ISREG(ip->i_d.di_mode)) | |
2a82b8be DC |
585 | return -EINVAL; |
586 | ||
587 | mp = pip->i_mount; | |
588 | cache = mp->m_filestream; | |
2a82b8be DC |
589 | |
590 | /* | |
591 | * We have a problem, Houston. | |
592 | * | |
593 | * Taking the iolock here violates inode locking order - we already | |
594 | * hold the ilock. Hence if we block getting this lock we may never | |
595 | * wake. Unfortunately, that means if we can't get the lock, we're | |
596 | * screwed in terms of getting a stream association - we can't spin | |
597 | * waiting for the lock because someone else is waiting on the lock we | |
598 | * hold and we cannot drop that as we are in a transaction here. | |
599 | * | |
075fe102 CH |
600 | * Lucky for us, this inversion is not a problem because it's a |
601 | * directory inode that we are trying to lock here. | |
2a82b8be DC |
602 | * |
603 | * So, if we can't get the iolock without sleeping then just give up | |
604 | */ | |
1c1c6ebc | 605 | if (!xfs_ilock_nowait(pip, XFS_IOLOCK_EXCL)) |
2a82b8be | 606 | return 1; |
2a82b8be DC |
607 | |
608 | /* If the parent directory is already in the cache, use its AG. */ | |
609 | item = xfs_mru_cache_lookup(cache, pip->i_ino); | |
610 | if (item) { | |
611 | ASSERT(item->ip == pip); | |
612 | ag = item->ag; | |
613 | xfs_mru_cache_done(cache); | |
614 | ||
615 | TRACE_LOOKUP(mp, pip, pip, ag, xfs_filestream_peek_ag(mp, ag)); | |
616 | err = _xfs_filestream_update_ag(ip, pip, ag); | |
617 | ||
618 | goto exit; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Set the starting AG using the rotor for inode32, otherwise | |
623 | * use the directory inode's AG. | |
624 | */ | |
625 | if (mp->m_flags & XFS_MOUNT_32BITINODES) { | |
626 | rotorstep = xfs_rotorstep; | |
627 | startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount; | |
628 | mp->m_agfrotor = (mp->m_agfrotor + 1) % | |
629 | (mp->m_sb.sb_agcount * rotorstep); | |
630 | } else | |
631 | startag = XFS_INO_TO_AGNO(mp, pip->i_ino); | |
632 | ||
633 | /* Pick a new AG for the parent inode starting at startag. */ | |
634 | err = _xfs_filestream_pick_ag(mp, startag, &ag, 0, 0); | |
635 | if (err || ag == NULLAGNUMBER) | |
636 | goto exit_did_pick; | |
637 | ||
638 | /* Associate the parent inode with the AG. */ | |
639 | err = _xfs_filestream_update_ag(pip, NULL, ag); | |
640 | if (err) | |
641 | goto exit_did_pick; | |
642 | ||
643 | /* Associate the file inode with the AG. */ | |
644 | err = _xfs_filestream_update_ag(ip, pip, ag); | |
645 | if (err) | |
646 | goto exit_did_pick; | |
647 | ||
648 | TRACE_ASSOCIATE(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag)); | |
649 | ||
650 | exit_did_pick: | |
651 | /* | |
652 | * If _xfs_filestream_pick_ag() returned a valid AG, remove the | |
653 | * reference it took on it, since the file and directory will have taken | |
654 | * their own now if they were successfully cached. | |
655 | */ | |
656 | if (ag != NULLAGNUMBER) | |
657 | xfs_filestream_put_ag(mp, ag); | |
658 | ||
659 | exit: | |
660 | xfs_iunlock(pip, XFS_IOLOCK_EXCL); | |
2a82b8be DC |
661 | return -err; |
662 | } | |
663 | ||
664 | /* | |
665 | * Pick a new allocation group for the current file and its file stream. This | |
666 | * function is called by xfs_bmap_filestreams() with the mount point's per-ag | |
667 | * lock held. | |
668 | */ | |
669 | int | |
670 | xfs_filestream_new_ag( | |
671 | xfs_bmalloca_t *ap, | |
672 | xfs_agnumber_t *agp) | |
673 | { | |
674 | int flags, err; | |
675 | xfs_inode_t *ip, *pip = NULL; | |
676 | xfs_mount_t *mp; | |
677 | xfs_mru_cache_t *cache; | |
678 | xfs_extlen_t minlen; | |
679 | fstrm_item_t *dir, *file; | |
680 | xfs_agnumber_t ag = NULLAGNUMBER; | |
681 | ||
682 | ip = ap->ip; | |
683 | mp = ip->i_mount; | |
684 | cache = mp->m_filestream; | |
685 | minlen = ap->alen; | |
686 | *agp = NULLAGNUMBER; | |
687 | ||
688 | /* | |
689 | * Look for the file in the cache, removing it if it's found. Doing | |
690 | * this allows it to be held across the dir lookup that follows. | |
691 | */ | |
692 | file = xfs_mru_cache_remove(cache, ip->i_ino); | |
693 | if (file) { | |
694 | ASSERT(ip == file->ip); | |
695 | ||
696 | /* Save the file's parent inode and old AG number for later. */ | |
697 | pip = file->pip; | |
698 | ag = file->ag; | |
699 | ||
700 | /* Look for the file's directory in the cache. */ | |
701 | dir = xfs_mru_cache_lookup(cache, pip->i_ino); | |
702 | if (dir) { | |
703 | ASSERT(pip == dir->ip); | |
704 | ||
705 | /* | |
706 | * If the directory has already moved on to a new AG, | |
707 | * use that AG as the new AG for the file. Don't | |
708 | * forget to twiddle the AG refcounts to match the | |
709 | * movement. | |
710 | */ | |
711 | if (dir->ag != file->ag) { | |
712 | xfs_filestream_put_ag(mp, file->ag); | |
713 | xfs_filestream_get_ag(mp, dir->ag); | |
714 | *agp = file->ag = dir->ag; | |
715 | } | |
716 | ||
717 | xfs_mru_cache_done(cache); | |
718 | } | |
719 | ||
720 | /* | |
721 | * Put the file back in the cache. If this fails, the free | |
722 | * function needs to be called to tidy up in the same way as if | |
723 | * the item had simply expired from the cache. | |
724 | */ | |
725 | err = xfs_mru_cache_insert(cache, ip->i_ino, file); | |
726 | if (err) { | |
727 | xfs_fstrm_free_func(ip->i_ino, file); | |
728 | return err; | |
729 | } | |
730 | ||
731 | /* | |
732 | * If the file's AG was moved to the directory's new AG, there's | |
733 | * nothing more to be done. | |
734 | */ | |
735 | if (*agp != NULLAGNUMBER) { | |
736 | TRACE_MOVEAG(mp, ip, pip, | |
737 | ag, xfs_filestream_peek_ag(mp, ag), | |
738 | *agp, xfs_filestream_peek_ag(mp, *agp)); | |
739 | return 0; | |
740 | } | |
741 | } | |
742 | ||
743 | /* | |
744 | * If the file's parent directory is known, take its iolock in exclusive | |
745 | * mode to prevent two sibling files from racing each other to migrate | |
746 | * themselves and their parent to different AGs. | |
785ce418 CH |
747 | * |
748 | * Note that we lock the parent directory iolock inside the child | |
749 | * iolock here. That's fine as we never hold both parent and child | |
750 | * iolock in any other place. This is different from the ilock, | |
751 | * which requires locking of the child after the parent for namespace | |
752 | * operations. | |
2a82b8be DC |
753 | */ |
754 | if (pip) | |
785ce418 | 755 | xfs_ilock(pip, XFS_IOLOCK_EXCL | XFS_IOLOCK_PARENT); |
2a82b8be DC |
756 | |
757 | /* | |
758 | * A new AG needs to be found for the file. If the file's parent | |
759 | * directory is also known, it will be moved to the new AG as well to | |
760 | * ensure that files created inside it in future use the new AG. | |
761 | */ | |
762 | ag = (ag == NULLAGNUMBER) ? 0 : (ag + 1) % mp->m_sb.sb_agcount; | |
763 | flags = (ap->userdata ? XFS_PICK_USERDATA : 0) | | |
764 | (ap->low ? XFS_PICK_LOWSPACE : 0); | |
765 | ||
766 | err = _xfs_filestream_pick_ag(mp, ag, agp, flags, minlen); | |
767 | if (err || *agp == NULLAGNUMBER) | |
768 | goto exit; | |
769 | ||
770 | /* | |
771 | * If the file wasn't found in the file cache, then its parent directory | |
772 | * inode isn't known. For this to have happened, the file must either | |
773 | * be pre-existing, or it was created long enough ago that its cache | |
774 | * entry has expired. This isn't the sort of usage that the filestreams | |
775 | * allocator is trying to optimise, so there's no point trying to track | |
776 | * its new AG somehow in the filestream data structures. | |
777 | */ | |
778 | if (!pip) { | |
779 | TRACE_ORPHAN(mp, ip, *agp); | |
780 | goto exit; | |
781 | } | |
782 | ||
783 | /* Associate the parent inode with the AG. */ | |
784 | err = _xfs_filestream_update_ag(pip, NULL, *agp); | |
785 | if (err) | |
786 | goto exit; | |
787 | ||
788 | /* Associate the file inode with the AG. */ | |
789 | err = _xfs_filestream_update_ag(ip, pip, *agp); | |
790 | if (err) | |
791 | goto exit; | |
792 | ||
793 | TRACE_MOVEAG(mp, ip, pip, NULLAGNUMBER, 0, | |
794 | *agp, xfs_filestream_peek_ag(mp, *agp)); | |
795 | ||
796 | exit: | |
797 | /* | |
798 | * If _xfs_filestream_pick_ag() returned a valid AG, remove the | |
799 | * reference it took on it, since the file and directory will have taken | |
800 | * their own now if they were successfully cached. | |
801 | */ | |
802 | if (*agp != NULLAGNUMBER) | |
803 | xfs_filestream_put_ag(mp, *agp); | |
804 | else | |
805 | *agp = 0; | |
806 | ||
807 | if (pip) | |
808 | xfs_iunlock(pip, XFS_IOLOCK_EXCL); | |
809 | ||
810 | return err; | |
811 | } | |
812 | ||
813 | /* | |
814 | * Remove an association between an inode and a filestream object. | |
815 | * Typically this is done on last close of an unlinked file. | |
816 | */ | |
817 | void | |
818 | xfs_filestream_deassociate( | |
819 | xfs_inode_t *ip) | |
820 | { | |
821 | xfs_mru_cache_t *cache = ip->i_mount->m_filestream; | |
822 | ||
823 | xfs_mru_cache_delete(cache, ip->i_ino); | |
824 | } |