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" | |
3ab78df2 | 25 | #include "xfs_defer.h" |
2a82b8be | 26 | #include "xfs_inode.h" |
2a82b8be | 27 | #include "xfs_bmap.h" |
68988114 | 28 | #include "xfs_bmap_util.h" |
2a82b8be | 29 | #include "xfs_alloc.h" |
2a82b8be DC |
30 | #include "xfs_mru_cache.h" |
31 | #include "xfs_filestream.h" | |
0b1b213f | 32 | #include "xfs_trace.h" |
2a82b8be | 33 | |
2cd2ef6a CH |
34 | struct xfs_fstrm_item { |
35 | struct xfs_mru_cache_elem mru; | |
36 | struct xfs_inode *ip; | |
37 | xfs_agnumber_t ag; /* AG in use for this directory */ | |
38 | }; | |
39 | ||
40 | enum xfs_fstrm_alloc { | |
41 | XFS_PICK_USERDATA = 1, | |
42 | XFS_PICK_LOWSPACE = 2, | |
43 | }; | |
2a82b8be | 44 | |
0664ce8d CH |
45 | /* |
46 | * Allocation group filestream associations are tracked with per-ag atomic | |
2cd2ef6a | 47 | * counters. These counters allow xfs_filestream_pick_ag() to tell whether a |
0664ce8d CH |
48 | * particular AG already has active filestreams associated with it. The mount |
49 | * point's m_peraglock is used to protect these counters from per-ag array | |
50 | * re-allocation during a growfs operation. When xfs_growfs_data_private() is | |
51 | * about to reallocate the array, it calls xfs_filestream_flush() with the | |
52 | * m_peraglock held in write mode. | |
53 | * | |
54 | * Since xfs_mru_cache_flush() guarantees that all the free functions for all | |
55 | * the cache elements have finished executing before it returns, it's safe for | |
56 | * the free functions to use the atomic counters without m_peraglock protection. | |
57 | * This allows the implementation of xfs_fstrm_free_func() to be agnostic about | |
58 | * whether it was called with the m_peraglock held in read mode, write mode or | |
59 | * not held at all. The race condition this addresses is the following: | |
60 | * | |
61 | * - The work queue scheduler fires and pulls a filestream directory cache | |
62 | * element off the LRU end of the cache for deletion, then gets pre-empted. | |
63 | * - A growfs operation grabs the m_peraglock in write mode, flushes all the | |
64 | * remaining items from the cache and reallocates the mount point's per-ag | |
65 | * array, resetting all the counters to zero. | |
66 | * - The work queue thread resumes and calls the free function for the element | |
67 | * it started cleaning up earlier. In the process it decrements the | |
68 | * filestreams counter for an AG that now has no references. | |
69 | * | |
70 | * With a shrinkfs feature, the above scenario could panic the system. | |
71 | * | |
72 | * All other uses of the following macros should be protected by either the | |
73 | * m_peraglock held in read mode, or the cache's internal locking exposed by the | |
74 | * interval between a call to xfs_mru_cache_lookup() and a call to | |
75 | * xfs_mru_cache_done(). In addition, the m_peraglock must be held in read mode | |
76 | * when new elements are added to the cache. | |
77 | * | |
78 | * Combined, these locking rules ensure that no associations will ever exist in | |
79 | * the cache that reference per-ag array elements that have since been | |
80 | * reallocated. | |
81 | */ | |
b94acd47 | 82 | int |
0664ce8d CH |
83 | xfs_filestream_peek_ag( |
84 | xfs_mount_t *mp, | |
85 | xfs_agnumber_t agno) | |
86 | { | |
87 | struct xfs_perag *pag; | |
88 | int ret; | |
89 | ||
90 | pag = xfs_perag_get(mp, agno); | |
91 | ret = atomic_read(&pag->pagf_fstrms); | |
92 | xfs_perag_put(pag); | |
93 | return ret; | |
94 | } | |
95 | ||
96 | static int | |
97 | xfs_filestream_get_ag( | |
98 | xfs_mount_t *mp, | |
99 | xfs_agnumber_t agno) | |
100 | { | |
101 | struct xfs_perag *pag; | |
102 | int ret; | |
103 | ||
104 | pag = xfs_perag_get(mp, agno); | |
105 | ret = atomic_inc_return(&pag->pagf_fstrms); | |
106 | xfs_perag_put(pag); | |
107 | return ret; | |
108 | } | |
109 | ||
110 | static void | |
111 | xfs_filestream_put_ag( | |
112 | xfs_mount_t *mp, | |
113 | xfs_agnumber_t agno) | |
114 | { | |
115 | struct xfs_perag *pag; | |
116 | ||
117 | pag = xfs_perag_get(mp, agno); | |
118 | atomic_dec(&pag->pagf_fstrms); | |
119 | xfs_perag_put(pag); | |
120 | } | |
2a82b8be | 121 | |
2cd2ef6a CH |
122 | static void |
123 | xfs_fstrm_free_func( | |
124 | struct xfs_mru_cache_elem *mru) | |
125 | { | |
126 | struct xfs_fstrm_item *item = | |
127 | container_of(mru, struct xfs_fstrm_item, mru); | |
128 | ||
129 | xfs_filestream_put_ag(item->ip->i_mount, item->ag); | |
130 | ||
b94acd47 | 131 | trace_xfs_filestream_free(item->ip, item->ag); |
2cd2ef6a | 132 | |
1919adda | 133 | kmem_free(item); |
2cd2ef6a CH |
134 | } |
135 | ||
2a82b8be DC |
136 | /* |
137 | * Scan the AGs starting at startag looking for an AG that isn't in use and has | |
138 | * at least minlen blocks free. | |
139 | */ | |
140 | static int | |
2cd2ef6a CH |
141 | xfs_filestream_pick_ag( |
142 | struct xfs_inode *ip, | |
143 | xfs_agnumber_t startag, | |
144 | xfs_agnumber_t *agp, | |
145 | int flags, | |
146 | xfs_extlen_t minlen) | |
2a82b8be | 147 | { |
2cd2ef6a CH |
148 | struct xfs_mount *mp = ip->i_mount; |
149 | struct xfs_fstrm_item *item; | |
150 | struct xfs_perag *pag; | |
b94acd47 | 151 | xfs_extlen_t longest, free = 0, minfree, maxfree = 0; |
2cd2ef6a | 152 | xfs_agnumber_t ag, max_ag = NULLAGNUMBER; |
2cd2ef6a CH |
153 | int err, trylock, nscan; |
154 | ||
c19b3b05 | 155 | ASSERT(S_ISDIR(VFS_I(ip)->i_mode)); |
2a82b8be DC |
156 | |
157 | /* 2% of an AG's blocks must be free for it to be chosen. */ | |
158 | minfree = mp->m_sb.sb_agblocks / 50; | |
159 | ||
160 | ag = startag; | |
161 | *agp = NULLAGNUMBER; | |
162 | ||
163 | /* For the first pass, don't sleep trying to init the per-AG. */ | |
164 | trylock = XFS_ALLOC_FLAG_TRYLOCK; | |
165 | ||
166 | for (nscan = 0; 1; nscan++) { | |
b94acd47 CH |
167 | trace_xfs_filestream_scan(ip, ag); |
168 | ||
4196ac08 | 169 | pag = xfs_perag_get(mp, ag); |
2a82b8be DC |
170 | |
171 | if (!pag->pagf_init) { | |
172 | err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); | |
4196ac08 DC |
173 | if (err && !trylock) { |
174 | xfs_perag_put(pag); | |
2a82b8be | 175 | return err; |
4196ac08 | 176 | } |
2a82b8be DC |
177 | } |
178 | ||
179 | /* Might fail sometimes during the 1st pass with trylock set. */ | |
180 | if (!pag->pagf_init) | |
181 | goto next_ag; | |
182 | ||
183 | /* Keep track of the AG with the most free blocks. */ | |
184 | if (pag->pagf_freeblks > maxfree) { | |
185 | maxfree = pag->pagf_freeblks; | |
186 | max_ag = ag; | |
187 | } | |
188 | ||
189 | /* | |
190 | * The AG reference count does two things: it enforces mutual | |
191 | * exclusion when examining the suitability of an AG in this | |
192 | * loop, and it guards against two filestreams being established | |
193 | * in the same AG as each other. | |
194 | */ | |
195 | if (xfs_filestream_get_ag(mp, ag) > 1) { | |
196 | xfs_filestream_put_ag(mp, ag); | |
197 | goto next_ag; | |
198 | } | |
199 | ||
50adbcb4 | 200 | longest = xfs_alloc_longest_free_extent(mp, pag, |
496817b4 | 201 | xfs_alloc_min_freelist(mp, pag)); |
2a82b8be DC |
202 | if (((minlen && longest >= minlen) || |
203 | (!minlen && pag->pagf_freeblks >= minfree)) && | |
204 | (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) || | |
205 | (flags & XFS_PICK_LOWSPACE))) { | |
206 | ||
207 | /* Break out, retaining the reference on the AG. */ | |
208 | free = pag->pagf_freeblks; | |
4196ac08 | 209 | xfs_perag_put(pag); |
2a82b8be DC |
210 | *agp = ag; |
211 | break; | |
212 | } | |
213 | ||
214 | /* Drop the reference on this AG, it's not usable. */ | |
215 | xfs_filestream_put_ag(mp, ag); | |
216 | next_ag: | |
4196ac08 | 217 | xfs_perag_put(pag); |
2a82b8be DC |
218 | /* Move to the next AG, wrapping to AG 0 if necessary. */ |
219 | if (++ag >= mp->m_sb.sb_agcount) | |
220 | ag = 0; | |
221 | ||
222 | /* If a full pass of the AGs hasn't been done yet, continue. */ | |
223 | if (ag != startag) | |
224 | continue; | |
225 | ||
226 | /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */ | |
227 | if (trylock != 0) { | |
228 | trylock = 0; | |
229 | continue; | |
230 | } | |
231 | ||
232 | /* Finally, if lowspace wasn't set, set it for the 3rd pass. */ | |
233 | if (!(flags & XFS_PICK_LOWSPACE)) { | |
234 | flags |= XFS_PICK_LOWSPACE; | |
235 | continue; | |
236 | } | |
237 | ||
238 | /* | |
239 | * Take the AG with the most free space, regardless of whether | |
240 | * it's already in use by another filestream. | |
241 | */ | |
242 | if (max_ag != NULLAGNUMBER) { | |
243 | xfs_filestream_get_ag(mp, max_ag); | |
2a82b8be DC |
244 | free = maxfree; |
245 | *agp = max_ag; | |
246 | break; | |
247 | } | |
248 | ||
249 | /* take AG 0 if none matched */ | |
b94acd47 | 250 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be DC |
251 | *agp = 0; |
252 | return 0; | |
253 | } | |
254 | ||
b94acd47 | 255 | trace_xfs_filestream_pick(ip, *agp, free, nscan); |
2a82b8be | 256 | |
2cd2ef6a | 257 | if (*agp == NULLAGNUMBER) |
2a82b8be | 258 | return 0; |
2a82b8be | 259 | |
2451337d | 260 | err = -ENOMEM; |
1919adda | 261 | item = kmem_alloc(sizeof(*item), KM_MAYFAIL); |
2a82b8be | 262 | if (!item) |
2cd2ef6a | 263 | goto out_put_ag; |
2a82b8be | 264 | |
2cd2ef6a | 265 | item->ag = *agp; |
2a82b8be | 266 | item->ip = ip; |
2a82b8be | 267 | |
22328d71 | 268 | err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru); |
2a82b8be | 269 | if (err) { |
2451337d | 270 | if (err == -EEXIST) |
2cd2ef6a CH |
271 | err = 0; |
272 | goto out_free_item; | |
2a82b8be DC |
273 | } |
274 | ||
2a82b8be | 275 | return 0; |
2a82b8be | 276 | |
2cd2ef6a | 277 | out_free_item: |
1919adda | 278 | kmem_free(item); |
2cd2ef6a CH |
279 | out_put_ag: |
280 | xfs_filestream_put_ag(mp, *agp); | |
281 | return err; | |
2a82b8be DC |
282 | } |
283 | ||
2cd2ef6a CH |
284 | static struct xfs_inode * |
285 | xfs_filestream_get_parent( | |
286 | struct xfs_inode *ip) | |
2a82b8be | 287 | { |
2cd2ef6a CH |
288 | struct inode *inode = VFS_I(ip), *dir = NULL; |
289 | struct dentry *dentry, *parent; | |
2a82b8be | 290 | |
2cd2ef6a CH |
291 | dentry = d_find_alias(inode); |
292 | if (!dentry) | |
293 | goto out; | |
2a82b8be | 294 | |
2cd2ef6a CH |
295 | parent = dget_parent(dentry); |
296 | if (!parent) | |
297 | goto out_dput; | |
2a82b8be | 298 | |
2b0143b5 | 299 | dir = igrab(d_inode(parent)); |
2cd2ef6a | 300 | dput(parent); |
2a82b8be | 301 | |
2cd2ef6a CH |
302 | out_dput: |
303 | dput(dentry); | |
304 | out: | |
305 | return dir ? XFS_I(dir) : NULL; | |
2a82b8be DC |
306 | } |
307 | ||
2a82b8be | 308 | /* |
3b8d9076 CH |
309 | * Find the right allocation group for a file, either by finding an |
310 | * existing file stream or creating a new one. | |
311 | * | |
312 | * Returns NULLAGNUMBER in case of an error. | |
2a82b8be DC |
313 | */ |
314 | xfs_agnumber_t | |
315 | xfs_filestream_lookup_ag( | |
2cd2ef6a | 316 | struct xfs_inode *ip) |
2a82b8be | 317 | { |
2cd2ef6a | 318 | struct xfs_mount *mp = ip->i_mount; |
2cd2ef6a | 319 | struct xfs_inode *pip = NULL; |
3b8d9076 | 320 | xfs_agnumber_t startag, ag = NULLAGNUMBER; |
22328d71 | 321 | struct xfs_mru_cache_elem *mru; |
2a82b8be | 322 | |
c19b3b05 | 323 | ASSERT(S_ISREG(VFS_I(ip)->i_mode)); |
2a82b8be | 324 | |
2cd2ef6a CH |
325 | pip = xfs_filestream_get_parent(ip); |
326 | if (!pip) | |
b26384dc | 327 | return NULLAGNUMBER; |
2cd2ef6a CH |
328 | |
329 | mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino); | |
22328d71 | 330 | if (mru) { |
3b8d9076 | 331 | ag = container_of(mru, struct xfs_fstrm_item, mru)->ag; |
22328d71 | 332 | xfs_mru_cache_done(mp->m_filestream); |
3b8d9076 | 333 | |
b94acd47 | 334 | trace_xfs_filestream_lookup(ip, ag); |
3b8d9076 | 335 | goto out; |
2a82b8be DC |
336 | } |
337 | ||
338 | /* | |
339 | * Set the starting AG using the rotor for inode32, otherwise | |
340 | * use the directory inode's AG. | |
341 | */ | |
342 | if (mp->m_flags & XFS_MOUNT_32BITINODES) { | |
2cd2ef6a | 343 | xfs_agnumber_t rotorstep = xfs_rotorstep; |
2a82b8be DC |
344 | startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount; |
345 | mp->m_agfrotor = (mp->m_agfrotor + 1) % | |
346 | (mp->m_sb.sb_agcount * rotorstep); | |
347 | } else | |
348 | startag = XFS_INO_TO_AGNO(mp, pip->i_ino); | |
349 | ||
3b8d9076 CH |
350 | if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0)) |
351 | ag = NULLAGNUMBER; | |
352 | out: | |
353 | IRELE(pip); | |
354 | return ag; | |
2a82b8be DC |
355 | } |
356 | ||
357 | /* | |
2cd2ef6a CH |
358 | * Pick a new allocation group for the current file and its file stream. |
359 | * | |
360 | * This is called when the allocator can't find a suitable extent in the | |
361 | * current AG, and we have to move the stream into a new AG with more space. | |
2a82b8be DC |
362 | */ |
363 | int | |
364 | xfs_filestream_new_ag( | |
68988114 DC |
365 | struct xfs_bmalloca *ap, |
366 | xfs_agnumber_t *agp) | |
2a82b8be | 367 | { |
2cd2ef6a CH |
368 | struct xfs_inode *ip = ap->ip, *pip; |
369 | struct xfs_mount *mp = ip->i_mount; | |
370 | xfs_extlen_t minlen = ap->length; | |
371 | xfs_agnumber_t startag = 0; | |
372 | int flags, err = 0; | |
373 | struct xfs_mru_cache_elem *mru; | |
2a82b8be | 374 | |
2cd2ef6a | 375 | *agp = NULLAGNUMBER; |
2a82b8be | 376 | |
2cd2ef6a CH |
377 | pip = xfs_filestream_get_parent(ip); |
378 | if (!pip) | |
379 | goto exit; | |
2a82b8be | 380 | |
2cd2ef6a CH |
381 | mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino); |
382 | if (mru) { | |
383 | struct xfs_fstrm_item *item = | |
384 | container_of(mru, struct xfs_fstrm_item, mru); | |
385 | startag = (item->ag + 1) % mp->m_sb.sb_agcount; | |
2a82b8be DC |
386 | } |
387 | ||
2a82b8be | 388 | flags = (ap->userdata ? XFS_PICK_USERDATA : 0) | |
2c3234d1 | 389 | (ap->dfops->dop_low ? XFS_PICK_LOWSPACE : 0); |
2a82b8be | 390 | |
2cd2ef6a | 391 | err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen); |
2a82b8be DC |
392 | |
393 | /* | |
2cd2ef6a | 394 | * Only free the item here so we skip over the old AG earlier. |
2a82b8be | 395 | */ |
2cd2ef6a CH |
396 | if (mru) |
397 | xfs_fstrm_free_func(mru); | |
2a82b8be | 398 | |
2cd2ef6a CH |
399 | IRELE(pip); |
400 | exit: | |
401 | if (*agp == NULLAGNUMBER) | |
402 | *agp = 0; | |
403 | return err; | |
404 | } | |
2a82b8be | 405 | |
2cd2ef6a CH |
406 | void |
407 | xfs_filestream_deassociate( | |
408 | struct xfs_inode *ip) | |
409 | { | |
410 | xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino); | |
411 | } | |
2a82b8be | 412 | |
2cd2ef6a CH |
413 | int |
414 | xfs_filestream_mount( | |
415 | xfs_mount_t *mp) | |
416 | { | |
2a82b8be | 417 | /* |
2cd2ef6a CH |
418 | * The filestream timer tunable is currently fixed within the range of |
419 | * one second to four minutes, with five seconds being the default. The | |
420 | * group count is somewhat arbitrary, but it'd be nice to adhere to the | |
421 | * timer tunable to within about 10 percent. This requires at least 10 | |
422 | * groups. | |
2a82b8be | 423 | */ |
2cd2ef6a CH |
424 | return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10, |
425 | 10, xfs_fstrm_free_func); | |
426 | } | |
2a82b8be | 427 | |
2cd2ef6a CH |
428 | void |
429 | xfs_filestream_unmount( | |
430 | xfs_mount_t *mp) | |
431 | { | |
432 | xfs_mru_cache_destroy(mp->m_filestream); | |
433 | } |