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0b61f8a4 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2a82b8be DC |
2 | /* |
3 | * Copyright (c) 2006-2007 Silicon Graphics, Inc. | |
2cd2ef6a | 4 | * Copyright (c) 2014 Christoph Hellwig. |
2a82b8be | 5 | * All Rights Reserved. |
2a82b8be DC |
6 | */ |
7 | #include "xfs.h" | |
5467b34b | 8 | #include "xfs_shared.h" |
a4fbe6ab | 9 | #include "xfs_format.h" |
239880ef DC |
10 | #include "xfs_log_format.h" |
11 | #include "xfs_trans_resv.h" | |
239880ef DC |
12 | #include "xfs_sb.h" |
13 | #include "xfs_mount.h" | |
2a82b8be | 14 | #include "xfs_inode.h" |
2a82b8be DC |
15 | #include "xfs_bmap.h" |
16 | #include "xfs_alloc.h" | |
2a82b8be | 17 | #include "xfs_mru_cache.h" |
0b1b213f | 18 | #include "xfs_trace.h" |
3fd129b6 | 19 | #include "xfs_ag_resv.h" |
3e3673e3 | 20 | #include "xfs_trans.h" |
2a82b8be | 21 | |
2cd2ef6a CH |
22 | struct xfs_fstrm_item { |
23 | struct xfs_mru_cache_elem mru; | |
2cd2ef6a CH |
24 | xfs_agnumber_t ag; /* AG in use for this directory */ |
25 | }; | |
26 | ||
27 | enum xfs_fstrm_alloc { | |
28 | XFS_PICK_USERDATA = 1, | |
29 | XFS_PICK_LOWSPACE = 2, | |
30 | }; | |
2a82b8be | 31 | |
0664ce8d CH |
32 | /* |
33 | * Allocation group filestream associations are tracked with per-ag atomic | |
2cd2ef6a | 34 | * counters. These counters allow xfs_filestream_pick_ag() to tell whether a |
0664ce8d CH |
35 | * particular AG already has active filestreams associated with it. The mount |
36 | * point's m_peraglock is used to protect these counters from per-ag array | |
37 | * re-allocation during a growfs operation. When xfs_growfs_data_private() is | |
38 | * about to reallocate the array, it calls xfs_filestream_flush() with the | |
39 | * m_peraglock held in write mode. | |
40 | * | |
41 | * Since xfs_mru_cache_flush() guarantees that all the free functions for all | |
42 | * the cache elements have finished executing before it returns, it's safe for | |
43 | * the free functions to use the atomic counters without m_peraglock protection. | |
44 | * This allows the implementation of xfs_fstrm_free_func() to be agnostic about | |
45 | * whether it was called with the m_peraglock held in read mode, write mode or | |
46 | * not held at all. The race condition this addresses is the following: | |
47 | * | |
48 | * - The work queue scheduler fires and pulls a filestream directory cache | |
49 | * element off the LRU end of the cache for deletion, then gets pre-empted. | |
50 | * - A growfs operation grabs the m_peraglock in write mode, flushes all the | |
51 | * remaining items from the cache and reallocates the mount point's per-ag | |
52 | * array, resetting all the counters to zero. | |
53 | * - The work queue thread resumes and calls the free function for the element | |
54 | * it started cleaning up earlier. In the process it decrements the | |
55 | * filestreams counter for an AG that now has no references. | |
56 | * | |
57 | * With a shrinkfs feature, the above scenario could panic the system. | |
58 | * | |
59 | * All other uses of the following macros should be protected by either the | |
60 | * m_peraglock held in read mode, or the cache's internal locking exposed by the | |
61 | * interval between a call to xfs_mru_cache_lookup() and a call to | |
62 | * xfs_mru_cache_done(). In addition, the m_peraglock must be held in read mode | |
63 | * when new elements are added to the cache. | |
64 | * | |
65 | * Combined, these locking rules ensure that no associations will ever exist in | |
66 | * the cache that reference per-ag array elements that have since been | |
67 | * reallocated. | |
68 | */ | |
b94acd47 | 69 | int |
0664ce8d CH |
70 | xfs_filestream_peek_ag( |
71 | xfs_mount_t *mp, | |
72 | xfs_agnumber_t agno) | |
73 | { | |
74 | struct xfs_perag *pag; | |
75 | int ret; | |
76 | ||
77 | pag = xfs_perag_get(mp, agno); | |
78 | ret = atomic_read(&pag->pagf_fstrms); | |
79 | xfs_perag_put(pag); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | static int | |
84 | xfs_filestream_get_ag( | |
85 | xfs_mount_t *mp, | |
86 | xfs_agnumber_t agno) | |
87 | { | |
88 | struct xfs_perag *pag; | |
89 | int ret; | |
90 | ||
91 | pag = xfs_perag_get(mp, agno); | |
92 | ret = atomic_inc_return(&pag->pagf_fstrms); | |
93 | xfs_perag_put(pag); | |
94 | return ret; | |
95 | } | |
96 | ||
97 | static void | |
98 | xfs_filestream_put_ag( | |
99 | xfs_mount_t *mp, | |
100 | xfs_agnumber_t agno) | |
101 | { | |
102 | struct xfs_perag *pag; | |
103 | ||
104 | pag = xfs_perag_get(mp, agno); | |
105 | atomic_dec(&pag->pagf_fstrms); | |
106 | xfs_perag_put(pag); | |
107 | } | |
2a82b8be | 108 | |
2cd2ef6a CH |
109 | static void |
110 | xfs_fstrm_free_func( | |
7fcd3efa | 111 | void *data, |
2cd2ef6a CH |
112 | struct xfs_mru_cache_elem *mru) |
113 | { | |
7fcd3efa | 114 | struct xfs_mount *mp = data; |
2cd2ef6a CH |
115 | struct xfs_fstrm_item *item = |
116 | container_of(mru, struct xfs_fstrm_item, mru); | |
117 | ||
7fcd3efa CH |
118 | xfs_filestream_put_ag(mp, item->ag); |
119 | trace_xfs_filestream_free(mp, mru->key, item->ag); | |
2cd2ef6a | 120 | |
1919adda | 121 | kmem_free(item); |
2cd2ef6a CH |
122 | } |
123 | ||
2a82b8be DC |
124 | /* |
125 | * Scan the AGs starting at startag looking for an AG that isn't in use and has | |
126 | * at least minlen blocks free. | |
127 | */ | |
128 | static int | |
2cd2ef6a CH |
129 | xfs_filestream_pick_ag( |
130 | struct xfs_inode *ip, | |
131 | xfs_agnumber_t startag, | |
132 | xfs_agnumber_t *agp, | |
133 | int flags, | |
134 | xfs_extlen_t minlen) | |
2a82b8be | 135 | { |
2cd2ef6a CH |
136 | struct xfs_mount *mp = ip->i_mount; |
137 | struct xfs_fstrm_item *item; | |
138 | struct xfs_perag *pag; | |
b94acd47 | 139 | xfs_extlen_t longest, free = 0, minfree, maxfree = 0; |
2cd2ef6a | 140 | xfs_agnumber_t ag, max_ag = NULLAGNUMBER; |
2cd2ef6a CH |
141 | int err, trylock, nscan; |
142 | ||
c19b3b05 | 143 | ASSERT(S_ISDIR(VFS_I(ip)->i_mode)); |
2a82b8be DC |
144 | |
145 | /* 2% of an AG's blocks must be free for it to be chosen. */ | |
146 | minfree = mp->m_sb.sb_agblocks / 50; | |
147 | ||
148 | ag = startag; | |
149 | *agp = NULLAGNUMBER; | |
150 | ||
151 | /* For the first pass, don't sleep trying to init the per-AG. */ | |
152 | trylock = XFS_ALLOC_FLAG_TRYLOCK; | |
153 | ||
154 | for (nscan = 0; 1; nscan++) { | |
7fcd3efa | 155 | trace_xfs_filestream_scan(mp, ip->i_ino, ag); |
b94acd47 | 156 | |
4196ac08 | 157 | pag = xfs_perag_get(mp, ag); |
2a82b8be DC |
158 | |
159 | if (!pag->pagf_init) { | |
160 | err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); | |
4196ac08 DC |
161 | if (err && !trylock) { |
162 | xfs_perag_put(pag); | |
2a82b8be | 163 | return err; |
4196ac08 | 164 | } |
2a82b8be DC |
165 | } |
166 | ||
167 | /* Might fail sometimes during the 1st pass with trylock set. */ | |
168 | if (!pag->pagf_init) | |
169 | goto next_ag; | |
170 | ||
171 | /* Keep track of the AG with the most free blocks. */ | |
172 | if (pag->pagf_freeblks > maxfree) { | |
173 | maxfree = pag->pagf_freeblks; | |
174 | max_ag = ag; | |
175 | } | |
176 | ||
177 | /* | |
178 | * The AG reference count does two things: it enforces mutual | |
179 | * exclusion when examining the suitability of an AG in this | |
180 | * loop, and it guards against two filestreams being established | |
181 | * in the same AG as each other. | |
182 | */ | |
183 | if (xfs_filestream_get_ag(mp, ag) > 1) { | |
184 | xfs_filestream_put_ag(mp, ag); | |
185 | goto next_ag; | |
186 | } | |
187 | ||
a1f69417 | 188 | longest = xfs_alloc_longest_free_extent(pag, |
3fd129b6 DW |
189 | xfs_alloc_min_freelist(mp, pag), |
190 | xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE)); | |
2a82b8be DC |
191 | if (((minlen && longest >= minlen) || |
192 | (!minlen && pag->pagf_freeblks >= minfree)) && | |
193 | (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) || | |
194 | (flags & XFS_PICK_LOWSPACE))) { | |
195 | ||
196 | /* Break out, retaining the reference on the AG. */ | |
197 | free = pag->pagf_freeblks; | |
4196ac08 | 198 | xfs_perag_put(pag); |
2a82b8be DC |
199 | *agp = ag; |
200 | break; | |
201 | } | |
202 | ||
203 | /* Drop the reference on this AG, it's not usable. */ | |
204 | xfs_filestream_put_ag(mp, ag); | |
205 | next_ag: | |
4196ac08 | 206 | xfs_perag_put(pag); |
2a82b8be DC |
207 | /* Move to the next AG, wrapping to AG 0 if necessary. */ |
208 | if (++ag >= mp->m_sb.sb_agcount) | |
209 | ag = 0; | |
210 | ||
211 | /* If a full pass of the AGs hasn't been done yet, continue. */ | |
212 | if (ag != startag) | |
213 | continue; | |
214 | ||
215 | /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */ | |
216 | if (trylock != 0) { | |
217 | trylock = 0; | |
218 | continue; | |
219 | } | |
220 | ||
221 | /* Finally, if lowspace wasn't set, set it for the 3rd pass. */ | |
222 | if (!(flags & XFS_PICK_LOWSPACE)) { | |
223 | flags |= XFS_PICK_LOWSPACE; | |
224 | continue; | |
225 | } | |
226 | ||
227 | /* | |
228 | * Take the AG with the most free space, regardless of whether | |
229 | * it's already in use by another filestream. | |
230 | */ | |
231 | if (max_ag != NULLAGNUMBER) { | |
232 | xfs_filestream_get_ag(mp, max_ag); | |
2a82b8be DC |
233 | free = maxfree; |
234 | *agp = max_ag; | |
235 | break; | |
236 | } | |
237 | ||
238 | /* take AG 0 if none matched */ | |
b94acd47 | 239 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be DC |
240 | *agp = 0; |
241 | return 0; | |
242 | } | |
243 | ||
b94acd47 | 244 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be | 245 | |
2cd2ef6a | 246 | if (*agp == NULLAGNUMBER) |
2a82b8be | 247 | return 0; |
2a82b8be | 248 | |
2451337d | 249 | err = -ENOMEM; |
1919adda | 250 | item = kmem_alloc(sizeof(*item), KM_MAYFAIL); |
2a82b8be | 251 | if (!item) |
2cd2ef6a | 252 | goto out_put_ag; |
2a82b8be | 253 | |
2cd2ef6a | 254 | item->ag = *agp; |
2a82b8be | 255 | |
22328d71 | 256 | err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru); |
2a82b8be | 257 | if (err) { |
2451337d | 258 | if (err == -EEXIST) |
2cd2ef6a CH |
259 | err = 0; |
260 | goto out_free_item; | |
2a82b8be DC |
261 | } |
262 | ||
2a82b8be | 263 | return 0; |
2a82b8be | 264 | |
2cd2ef6a | 265 | out_free_item: |
1919adda | 266 | kmem_free(item); |
2cd2ef6a CH |
267 | out_put_ag: |
268 | xfs_filestream_put_ag(mp, *agp); | |
269 | return err; | |
2a82b8be DC |
270 | } |
271 | ||
2cd2ef6a CH |
272 | static struct xfs_inode * |
273 | xfs_filestream_get_parent( | |
274 | struct xfs_inode *ip) | |
2a82b8be | 275 | { |
2cd2ef6a CH |
276 | struct inode *inode = VFS_I(ip), *dir = NULL; |
277 | struct dentry *dentry, *parent; | |
2a82b8be | 278 | |
2cd2ef6a CH |
279 | dentry = d_find_alias(inode); |
280 | if (!dentry) | |
281 | goto out; | |
2a82b8be | 282 | |
2cd2ef6a CH |
283 | parent = dget_parent(dentry); |
284 | if (!parent) | |
285 | goto out_dput; | |
2a82b8be | 286 | |
2b0143b5 | 287 | dir = igrab(d_inode(parent)); |
2cd2ef6a | 288 | dput(parent); |
2a82b8be | 289 | |
2cd2ef6a CH |
290 | out_dput: |
291 | dput(dentry); | |
292 | out: | |
293 | return dir ? XFS_I(dir) : NULL; | |
2a82b8be DC |
294 | } |
295 | ||
2a82b8be | 296 | /* |
3b8d9076 CH |
297 | * Find the right allocation group for a file, either by finding an |
298 | * existing file stream or creating a new one. | |
299 | * | |
300 | * Returns NULLAGNUMBER in case of an error. | |
2a82b8be DC |
301 | */ |
302 | xfs_agnumber_t | |
303 | xfs_filestream_lookup_ag( | |
2cd2ef6a | 304 | struct xfs_inode *ip) |
2a82b8be | 305 | { |
2cd2ef6a | 306 | struct xfs_mount *mp = ip->i_mount; |
2cd2ef6a | 307 | struct xfs_inode *pip = NULL; |
3b8d9076 | 308 | xfs_agnumber_t startag, ag = NULLAGNUMBER; |
22328d71 | 309 | struct xfs_mru_cache_elem *mru; |
2a82b8be | 310 | |
c19b3b05 | 311 | ASSERT(S_ISREG(VFS_I(ip)->i_mode)); |
2a82b8be | 312 | |
2cd2ef6a CH |
313 | pip = xfs_filestream_get_parent(ip); |
314 | if (!pip) | |
b26384dc | 315 | return NULLAGNUMBER; |
2cd2ef6a CH |
316 | |
317 | mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino); | |
22328d71 | 318 | if (mru) { |
3b8d9076 | 319 | ag = container_of(mru, struct xfs_fstrm_item, mru)->ag; |
22328d71 | 320 | xfs_mru_cache_done(mp->m_filestream); |
3b8d9076 | 321 | |
7fcd3efa | 322 | trace_xfs_filestream_lookup(mp, ip->i_ino, ag); |
3b8d9076 | 323 | goto out; |
2a82b8be DC |
324 | } |
325 | ||
326 | /* | |
327 | * Set the starting AG using the rotor for inode32, otherwise | |
328 | * use the directory inode's AG. | |
329 | */ | |
330 | if (mp->m_flags & XFS_MOUNT_32BITINODES) { | |
2cd2ef6a | 331 | xfs_agnumber_t rotorstep = xfs_rotorstep; |
2a82b8be DC |
332 | startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount; |
333 | mp->m_agfrotor = (mp->m_agfrotor + 1) % | |
334 | (mp->m_sb.sb_agcount * rotorstep); | |
335 | } else | |
336 | startag = XFS_INO_TO_AGNO(mp, pip->i_ino); | |
337 | ||
3b8d9076 CH |
338 | if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0)) |
339 | ag = NULLAGNUMBER; | |
340 | out: | |
44a8736b | 341 | xfs_irele(pip); |
3b8d9076 | 342 | return ag; |
2a82b8be DC |
343 | } |
344 | ||
345 | /* | |
2cd2ef6a CH |
346 | * Pick a new allocation group for the current file and its file stream. |
347 | * | |
348 | * This is called when the allocator can't find a suitable extent in the | |
349 | * current AG, and we have to move the stream into a new AG with more space. | |
2a82b8be DC |
350 | */ |
351 | int | |
352 | xfs_filestream_new_ag( | |
68988114 DC |
353 | struct xfs_bmalloca *ap, |
354 | xfs_agnumber_t *agp) | |
2a82b8be | 355 | { |
2cd2ef6a CH |
356 | struct xfs_inode *ip = ap->ip, *pip; |
357 | struct xfs_mount *mp = ip->i_mount; | |
358 | xfs_extlen_t minlen = ap->length; | |
359 | xfs_agnumber_t startag = 0; | |
292378ed DC |
360 | int flags = 0; |
361 | int err = 0; | |
2cd2ef6a | 362 | struct xfs_mru_cache_elem *mru; |
2a82b8be | 363 | |
2cd2ef6a | 364 | *agp = NULLAGNUMBER; |
2a82b8be | 365 | |
2cd2ef6a CH |
366 | pip = xfs_filestream_get_parent(ip); |
367 | if (!pip) | |
368 | goto exit; | |
2a82b8be | 369 | |
2cd2ef6a CH |
370 | mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino); |
371 | if (mru) { | |
372 | struct xfs_fstrm_item *item = | |
373 | container_of(mru, struct xfs_fstrm_item, mru); | |
374 | startag = (item->ag + 1) % mp->m_sb.sb_agcount; | |
2a82b8be DC |
375 | } |
376 | ||
292378ed DC |
377 | if (xfs_alloc_is_userdata(ap->datatype)) |
378 | flags |= XFS_PICK_USERDATA; | |
1214f1cf | 379 | if (ap->tp->t_flags & XFS_TRANS_LOWMODE) |
292378ed | 380 | flags |= XFS_PICK_LOWSPACE; |
2a82b8be | 381 | |
2cd2ef6a | 382 | err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen); |
2a82b8be DC |
383 | |
384 | /* | |
2cd2ef6a | 385 | * Only free the item here so we skip over the old AG earlier. |
2a82b8be | 386 | */ |
2cd2ef6a | 387 | if (mru) |
7fcd3efa | 388 | xfs_fstrm_free_func(mp, mru); |
2a82b8be | 389 | |
44a8736b | 390 | xfs_irele(pip); |
2cd2ef6a CH |
391 | exit: |
392 | if (*agp == NULLAGNUMBER) | |
393 | *agp = 0; | |
394 | return err; | |
395 | } | |
2a82b8be | 396 | |
2cd2ef6a CH |
397 | void |
398 | xfs_filestream_deassociate( | |
399 | struct xfs_inode *ip) | |
400 | { | |
401 | xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino); | |
402 | } | |
2a82b8be | 403 | |
2cd2ef6a CH |
404 | int |
405 | xfs_filestream_mount( | |
406 | xfs_mount_t *mp) | |
407 | { | |
2a82b8be | 408 | /* |
2cd2ef6a CH |
409 | * The filestream timer tunable is currently fixed within the range of |
410 | * one second to four minutes, with five seconds being the default. The | |
411 | * group count is somewhat arbitrary, but it'd be nice to adhere to the | |
412 | * timer tunable to within about 10 percent. This requires at least 10 | |
413 | * groups. | |
2a82b8be | 414 | */ |
7fcd3efa CH |
415 | return xfs_mru_cache_create(&mp->m_filestream, mp, |
416 | xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func); | |
2cd2ef6a | 417 | } |
2a82b8be | 418 | |
2cd2ef6a CH |
419 | void |
420 | xfs_filestream_unmount( | |
421 | xfs_mount_t *mp) | |
422 | { | |
423 | xfs_mru_cache_destroy(mp->m_filestream); | |
424 | } |