Commit | Line | Data |
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2a82b8be DC |
1 | /* |
2 | * Copyright (c) 2006-2007 Silicon Graphics, Inc. | |
2cd2ef6a | 3 | * Copyright (c) 2014 Christoph Hellwig. |
2a82b8be DC |
4 | * All Rights Reserved. |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it would be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write the Free Software Foundation, | |
17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | */ | |
19 | #include "xfs.h" | |
a4fbe6ab | 20 | #include "xfs_format.h" |
239880ef DC |
21 | #include "xfs_log_format.h" |
22 | #include "xfs_trans_resv.h" | |
239880ef DC |
23 | #include "xfs_sb.h" |
24 | #include "xfs_mount.h" | |
2a82b8be | 25 | #include "xfs_inode.h" |
2a82b8be | 26 | #include "xfs_bmap.h" |
68988114 | 27 | #include "xfs_bmap_util.h" |
2a82b8be | 28 | #include "xfs_alloc.h" |
2a82b8be DC |
29 | #include "xfs_mru_cache.h" |
30 | #include "xfs_filestream.h" | |
0b1b213f | 31 | #include "xfs_trace.h" |
2a82b8be | 32 | |
2cd2ef6a CH |
33 | struct xfs_fstrm_item { |
34 | struct xfs_mru_cache_elem mru; | |
35 | struct xfs_inode *ip; | |
36 | xfs_agnumber_t ag; /* AG in use for this directory */ | |
37 | }; | |
38 | ||
39 | enum xfs_fstrm_alloc { | |
40 | XFS_PICK_USERDATA = 1, | |
41 | XFS_PICK_LOWSPACE = 2, | |
42 | }; | |
2a82b8be | 43 | |
0664ce8d CH |
44 | /* |
45 | * Allocation group filestream associations are tracked with per-ag atomic | |
2cd2ef6a | 46 | * counters. These counters allow xfs_filestream_pick_ag() to tell whether a |
0664ce8d CH |
47 | * particular AG already has active filestreams associated with it. The mount |
48 | * point's m_peraglock is used to protect these counters from per-ag array | |
49 | * re-allocation during a growfs operation. When xfs_growfs_data_private() is | |
50 | * about to reallocate the array, it calls xfs_filestream_flush() with the | |
51 | * m_peraglock held in write mode. | |
52 | * | |
53 | * Since xfs_mru_cache_flush() guarantees that all the free functions for all | |
54 | * the cache elements have finished executing before it returns, it's safe for | |
55 | * the free functions to use the atomic counters without m_peraglock protection. | |
56 | * This allows the implementation of xfs_fstrm_free_func() to be agnostic about | |
57 | * whether it was called with the m_peraglock held in read mode, write mode or | |
58 | * not held at all. The race condition this addresses is the following: | |
59 | * | |
60 | * - The work queue scheduler fires and pulls a filestream directory cache | |
61 | * element off the LRU end of the cache for deletion, then gets pre-empted. | |
62 | * - A growfs operation grabs the m_peraglock in write mode, flushes all the | |
63 | * remaining items from the cache and reallocates the mount point's per-ag | |
64 | * array, resetting all the counters to zero. | |
65 | * - The work queue thread resumes and calls the free function for the element | |
66 | * it started cleaning up earlier. In the process it decrements the | |
67 | * filestreams counter for an AG that now has no references. | |
68 | * | |
69 | * With a shrinkfs feature, the above scenario could panic the system. | |
70 | * | |
71 | * All other uses of the following macros should be protected by either the | |
72 | * m_peraglock held in read mode, or the cache's internal locking exposed by the | |
73 | * interval between a call to xfs_mru_cache_lookup() and a call to | |
74 | * xfs_mru_cache_done(). In addition, the m_peraglock must be held in read mode | |
75 | * when new elements are added to the cache. | |
76 | * | |
77 | * Combined, these locking rules ensure that no associations will ever exist in | |
78 | * the cache that reference per-ag array elements that have since been | |
79 | * reallocated. | |
80 | */ | |
b94acd47 | 81 | int |
0664ce8d CH |
82 | xfs_filestream_peek_ag( |
83 | xfs_mount_t *mp, | |
84 | xfs_agnumber_t agno) | |
85 | { | |
86 | struct xfs_perag *pag; | |
87 | int ret; | |
88 | ||
89 | pag = xfs_perag_get(mp, agno); | |
90 | ret = atomic_read(&pag->pagf_fstrms); | |
91 | xfs_perag_put(pag); | |
92 | return ret; | |
93 | } | |
94 | ||
95 | static int | |
96 | xfs_filestream_get_ag( | |
97 | xfs_mount_t *mp, | |
98 | xfs_agnumber_t agno) | |
99 | { | |
100 | struct xfs_perag *pag; | |
101 | int ret; | |
102 | ||
103 | pag = xfs_perag_get(mp, agno); | |
104 | ret = atomic_inc_return(&pag->pagf_fstrms); | |
105 | xfs_perag_put(pag); | |
106 | return ret; | |
107 | } | |
108 | ||
109 | static void | |
110 | xfs_filestream_put_ag( | |
111 | xfs_mount_t *mp, | |
112 | xfs_agnumber_t agno) | |
113 | { | |
114 | struct xfs_perag *pag; | |
115 | ||
116 | pag = xfs_perag_get(mp, agno); | |
117 | atomic_dec(&pag->pagf_fstrms); | |
118 | xfs_perag_put(pag); | |
119 | } | |
2a82b8be | 120 | |
2cd2ef6a CH |
121 | static void |
122 | xfs_fstrm_free_func( | |
123 | struct xfs_mru_cache_elem *mru) | |
124 | { | |
125 | struct xfs_fstrm_item *item = | |
126 | container_of(mru, struct xfs_fstrm_item, mru); | |
127 | ||
128 | xfs_filestream_put_ag(item->ip->i_mount, item->ag); | |
129 | ||
b94acd47 | 130 | trace_xfs_filestream_free(item->ip, item->ag); |
2cd2ef6a | 131 | |
1919adda | 132 | kmem_free(item); |
2cd2ef6a CH |
133 | } |
134 | ||
2a82b8be DC |
135 | /* |
136 | * Scan the AGs starting at startag looking for an AG that isn't in use and has | |
137 | * at least minlen blocks free. | |
138 | */ | |
139 | static int | |
2cd2ef6a CH |
140 | xfs_filestream_pick_ag( |
141 | struct xfs_inode *ip, | |
142 | xfs_agnumber_t startag, | |
143 | xfs_agnumber_t *agp, | |
144 | int flags, | |
145 | xfs_extlen_t minlen) | |
2a82b8be | 146 | { |
2cd2ef6a CH |
147 | struct xfs_mount *mp = ip->i_mount; |
148 | struct xfs_fstrm_item *item; | |
149 | struct xfs_perag *pag; | |
b94acd47 | 150 | xfs_extlen_t longest, free = 0, minfree, maxfree = 0; |
2cd2ef6a | 151 | xfs_agnumber_t ag, max_ag = NULLAGNUMBER; |
2cd2ef6a CH |
152 | int err, trylock, nscan; |
153 | ||
c19b3b05 | 154 | ASSERT(S_ISDIR(VFS_I(ip)->i_mode)); |
2a82b8be DC |
155 | |
156 | /* 2% of an AG's blocks must be free for it to be chosen. */ | |
157 | minfree = mp->m_sb.sb_agblocks / 50; | |
158 | ||
159 | ag = startag; | |
160 | *agp = NULLAGNUMBER; | |
161 | ||
162 | /* For the first pass, don't sleep trying to init the per-AG. */ | |
163 | trylock = XFS_ALLOC_FLAG_TRYLOCK; | |
164 | ||
165 | for (nscan = 0; 1; nscan++) { | |
b94acd47 CH |
166 | trace_xfs_filestream_scan(ip, ag); |
167 | ||
4196ac08 | 168 | pag = xfs_perag_get(mp, ag); |
2a82b8be DC |
169 | |
170 | if (!pag->pagf_init) { | |
171 | err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); | |
4196ac08 DC |
172 | if (err && !trylock) { |
173 | xfs_perag_put(pag); | |
2a82b8be | 174 | return err; |
4196ac08 | 175 | } |
2a82b8be DC |
176 | } |
177 | ||
178 | /* Might fail sometimes during the 1st pass with trylock set. */ | |
179 | if (!pag->pagf_init) | |
180 | goto next_ag; | |
181 | ||
182 | /* Keep track of the AG with the most free blocks. */ | |
183 | if (pag->pagf_freeblks > maxfree) { | |
184 | maxfree = pag->pagf_freeblks; | |
185 | max_ag = ag; | |
186 | } | |
187 | ||
188 | /* | |
189 | * The AG reference count does two things: it enforces mutual | |
190 | * exclusion when examining the suitability of an AG in this | |
191 | * loop, and it guards against two filestreams being established | |
192 | * in the same AG as each other. | |
193 | */ | |
194 | if (xfs_filestream_get_ag(mp, ag) > 1) { | |
195 | xfs_filestream_put_ag(mp, ag); | |
196 | goto next_ag; | |
197 | } | |
198 | ||
50adbcb4 | 199 | longest = xfs_alloc_longest_free_extent(mp, pag, |
496817b4 | 200 | xfs_alloc_min_freelist(mp, pag)); |
2a82b8be DC |
201 | if (((minlen && longest >= minlen) || |
202 | (!minlen && pag->pagf_freeblks >= minfree)) && | |
203 | (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) || | |
204 | (flags & XFS_PICK_LOWSPACE))) { | |
205 | ||
206 | /* Break out, retaining the reference on the AG. */ | |
207 | free = pag->pagf_freeblks; | |
4196ac08 | 208 | xfs_perag_put(pag); |
2a82b8be DC |
209 | *agp = ag; |
210 | break; | |
211 | } | |
212 | ||
213 | /* Drop the reference on this AG, it's not usable. */ | |
214 | xfs_filestream_put_ag(mp, ag); | |
215 | next_ag: | |
4196ac08 | 216 | xfs_perag_put(pag); |
2a82b8be DC |
217 | /* Move to the next AG, wrapping to AG 0 if necessary. */ |
218 | if (++ag >= mp->m_sb.sb_agcount) | |
219 | ag = 0; | |
220 | ||
221 | /* If a full pass of the AGs hasn't been done yet, continue. */ | |
222 | if (ag != startag) | |
223 | continue; | |
224 | ||
225 | /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */ | |
226 | if (trylock != 0) { | |
227 | trylock = 0; | |
228 | continue; | |
229 | } | |
230 | ||
231 | /* Finally, if lowspace wasn't set, set it for the 3rd pass. */ | |
232 | if (!(flags & XFS_PICK_LOWSPACE)) { | |
233 | flags |= XFS_PICK_LOWSPACE; | |
234 | continue; | |
235 | } | |
236 | ||
237 | /* | |
238 | * Take the AG with the most free space, regardless of whether | |
239 | * it's already in use by another filestream. | |
240 | */ | |
241 | if (max_ag != NULLAGNUMBER) { | |
242 | xfs_filestream_get_ag(mp, max_ag); | |
2a82b8be DC |
243 | free = maxfree; |
244 | *agp = max_ag; | |
245 | break; | |
246 | } | |
247 | ||
248 | /* take AG 0 if none matched */ | |
b94acd47 | 249 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be DC |
250 | *agp = 0; |
251 | return 0; | |
252 | } | |
253 | ||
b94acd47 | 254 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be | 255 | |
2cd2ef6a | 256 | if (*agp == NULLAGNUMBER) |
2a82b8be | 257 | return 0; |
2a82b8be | 258 | |
2451337d | 259 | err = -ENOMEM; |
1919adda | 260 | item = kmem_alloc(sizeof(*item), KM_MAYFAIL); |
2a82b8be | 261 | if (!item) |
2cd2ef6a | 262 | goto out_put_ag; |
2a82b8be | 263 | |
2cd2ef6a | 264 | item->ag = *agp; |
2a82b8be | 265 | item->ip = ip; |
2a82b8be | 266 | |
22328d71 | 267 | err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru); |
2a82b8be | 268 | if (err) { |
2451337d | 269 | if (err == -EEXIST) |
2cd2ef6a CH |
270 | err = 0; |
271 | goto out_free_item; | |
2a82b8be DC |
272 | } |
273 | ||
2a82b8be | 274 | return 0; |
2a82b8be | 275 | |
2cd2ef6a | 276 | out_free_item: |
1919adda | 277 | kmem_free(item); |
2cd2ef6a CH |
278 | out_put_ag: |
279 | xfs_filestream_put_ag(mp, *agp); | |
280 | return err; | |
2a82b8be DC |
281 | } |
282 | ||
2cd2ef6a CH |
283 | static struct xfs_inode * |
284 | xfs_filestream_get_parent( | |
285 | struct xfs_inode *ip) | |
2a82b8be | 286 | { |
2cd2ef6a CH |
287 | struct inode *inode = VFS_I(ip), *dir = NULL; |
288 | struct dentry *dentry, *parent; | |
2a82b8be | 289 | |
2cd2ef6a CH |
290 | dentry = d_find_alias(inode); |
291 | if (!dentry) | |
292 | goto out; | |
2a82b8be | 293 | |
2cd2ef6a CH |
294 | parent = dget_parent(dentry); |
295 | if (!parent) | |
296 | goto out_dput; | |
2a82b8be | 297 | |
2b0143b5 | 298 | dir = igrab(d_inode(parent)); |
2cd2ef6a | 299 | dput(parent); |
2a82b8be | 300 | |
2cd2ef6a CH |
301 | out_dput: |
302 | dput(dentry); | |
303 | out: | |
304 | return dir ? XFS_I(dir) : NULL; | |
2a82b8be DC |
305 | } |
306 | ||
2a82b8be | 307 | /* |
3b8d9076 CH |
308 | * Find the right allocation group for a file, either by finding an |
309 | * existing file stream or creating a new one. | |
310 | * | |
311 | * Returns NULLAGNUMBER in case of an error. | |
2a82b8be DC |
312 | */ |
313 | xfs_agnumber_t | |
314 | xfs_filestream_lookup_ag( | |
2cd2ef6a | 315 | struct xfs_inode *ip) |
2a82b8be | 316 | { |
2cd2ef6a | 317 | struct xfs_mount *mp = ip->i_mount; |
2cd2ef6a | 318 | struct xfs_inode *pip = NULL; |
3b8d9076 | 319 | xfs_agnumber_t startag, ag = NULLAGNUMBER; |
22328d71 | 320 | struct xfs_mru_cache_elem *mru; |
2a82b8be | 321 | |
c19b3b05 | 322 | ASSERT(S_ISREG(VFS_I(ip)->i_mode)); |
2a82b8be | 323 | |
2cd2ef6a CH |
324 | pip = xfs_filestream_get_parent(ip); |
325 | if (!pip) | |
b26384dc | 326 | return NULLAGNUMBER; |
2cd2ef6a CH |
327 | |
328 | mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino); | |
22328d71 | 329 | if (mru) { |
3b8d9076 | 330 | ag = container_of(mru, struct xfs_fstrm_item, mru)->ag; |
22328d71 | 331 | xfs_mru_cache_done(mp->m_filestream); |
3b8d9076 | 332 | |
b94acd47 | 333 | trace_xfs_filestream_lookup(ip, ag); |
3b8d9076 | 334 | goto out; |
2a82b8be DC |
335 | } |
336 | ||
337 | /* | |
338 | * Set the starting AG using the rotor for inode32, otherwise | |
339 | * use the directory inode's AG. | |
340 | */ | |
341 | if (mp->m_flags & XFS_MOUNT_32BITINODES) { | |
2cd2ef6a | 342 | xfs_agnumber_t rotorstep = xfs_rotorstep; |
2a82b8be DC |
343 | startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount; |
344 | mp->m_agfrotor = (mp->m_agfrotor + 1) % | |
345 | (mp->m_sb.sb_agcount * rotorstep); | |
346 | } else | |
347 | startag = XFS_INO_TO_AGNO(mp, pip->i_ino); | |
348 | ||
3b8d9076 CH |
349 | if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0)) |
350 | ag = NULLAGNUMBER; | |
351 | out: | |
352 | IRELE(pip); | |
353 | return ag; | |
2a82b8be DC |
354 | } |
355 | ||
356 | /* | |
2cd2ef6a CH |
357 | * Pick a new allocation group for the current file and its file stream. |
358 | * | |
359 | * This is called when the allocator can't find a suitable extent in the | |
360 | * current AG, and we have to move the stream into a new AG with more space. | |
2a82b8be DC |
361 | */ |
362 | int | |
363 | xfs_filestream_new_ag( | |
68988114 DC |
364 | struct xfs_bmalloca *ap, |
365 | xfs_agnumber_t *agp) | |
2a82b8be | 366 | { |
2cd2ef6a CH |
367 | struct xfs_inode *ip = ap->ip, *pip; |
368 | struct xfs_mount *mp = ip->i_mount; | |
369 | xfs_extlen_t minlen = ap->length; | |
370 | xfs_agnumber_t startag = 0; | |
371 | int flags, err = 0; | |
372 | struct xfs_mru_cache_elem *mru; | |
2a82b8be | 373 | |
2cd2ef6a | 374 | *agp = NULLAGNUMBER; |
2a82b8be | 375 | |
2cd2ef6a CH |
376 | pip = xfs_filestream_get_parent(ip); |
377 | if (!pip) | |
378 | goto exit; | |
2a82b8be | 379 | |
2cd2ef6a CH |
380 | mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino); |
381 | if (mru) { | |
382 | struct xfs_fstrm_item *item = | |
383 | container_of(mru, struct xfs_fstrm_item, mru); | |
384 | startag = (item->ag + 1) % mp->m_sb.sb_agcount; | |
2a82b8be DC |
385 | } |
386 | ||
2a82b8be | 387 | flags = (ap->userdata ? XFS_PICK_USERDATA : 0) | |
0937e0fd | 388 | (ap->flist->xbf_low ? XFS_PICK_LOWSPACE : 0); |
2a82b8be | 389 | |
2cd2ef6a | 390 | err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen); |
2a82b8be DC |
391 | |
392 | /* | |
2cd2ef6a | 393 | * Only free the item here so we skip over the old AG earlier. |
2a82b8be | 394 | */ |
2cd2ef6a CH |
395 | if (mru) |
396 | xfs_fstrm_free_func(mru); | |
2a82b8be | 397 | |
2cd2ef6a CH |
398 | IRELE(pip); |
399 | exit: | |
400 | if (*agp == NULLAGNUMBER) | |
401 | *agp = 0; | |
402 | return err; | |
403 | } | |
2a82b8be | 404 | |
2cd2ef6a CH |
405 | void |
406 | xfs_filestream_deassociate( | |
407 | struct xfs_inode *ip) | |
408 | { | |
409 | xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino); | |
410 | } | |
2a82b8be | 411 | |
2cd2ef6a CH |
412 | int |
413 | xfs_filestream_mount( | |
414 | xfs_mount_t *mp) | |
415 | { | |
2a82b8be | 416 | /* |
2cd2ef6a CH |
417 | * The filestream timer tunable is currently fixed within the range of |
418 | * one second to four minutes, with five seconds being the default. The | |
419 | * group count is somewhat arbitrary, but it'd be nice to adhere to the | |
420 | * timer tunable to within about 10 percent. This requires at least 10 | |
421 | * groups. | |
2a82b8be | 422 | */ |
2cd2ef6a CH |
423 | return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10, |
424 | 10, xfs_fstrm_free_func); | |
425 | } | |
2a82b8be | 426 | |
2cd2ef6a CH |
427 | void |
428 | xfs_filestream_unmount( | |
429 | xfs_mount_t *mp) | |
430 | { | |
431 | xfs_mru_cache_destroy(mp->m_filestream); | |
432 | } |