Loading...
1/*
2 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
3 * Copyright (c) 2014 Christoph Hellwig.
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"
20#include "xfs_format.h"
21#include "xfs_log_format.h"
22#include "xfs_trans_resv.h"
23#include "xfs_sb.h"
24#include "xfs_mount.h"
25#include "xfs_defer.h"
26#include "xfs_inode.h"
27#include "xfs_bmap.h"
28#include "xfs_bmap_util.h"
29#include "xfs_alloc.h"
30#include "xfs_mru_cache.h"
31#include "xfs_filestream.h"
32#include "xfs_trace.h"
33#include "xfs_ag_resv.h"
34
35struct xfs_fstrm_item {
36 struct xfs_mru_cache_elem mru;
37 struct xfs_inode *ip;
38 xfs_agnumber_t ag; /* AG in use for this directory */
39};
40
41enum xfs_fstrm_alloc {
42 XFS_PICK_USERDATA = 1,
43 XFS_PICK_LOWSPACE = 2,
44};
45
46/*
47 * Allocation group filestream associations are tracked with per-ag atomic
48 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
49 * particular AG already has active filestreams associated with it. The mount
50 * point's m_peraglock is used to protect these counters from per-ag array
51 * re-allocation during a growfs operation. When xfs_growfs_data_private() is
52 * about to reallocate the array, it calls xfs_filestream_flush() with the
53 * m_peraglock held in write mode.
54 *
55 * Since xfs_mru_cache_flush() guarantees that all the free functions for all
56 * the cache elements have finished executing before it returns, it's safe for
57 * the free functions to use the atomic counters without m_peraglock protection.
58 * This allows the implementation of xfs_fstrm_free_func() to be agnostic about
59 * whether it was called with the m_peraglock held in read mode, write mode or
60 * not held at all. The race condition this addresses is the following:
61 *
62 * - The work queue scheduler fires and pulls a filestream directory cache
63 * element off the LRU end of the cache for deletion, then gets pre-empted.
64 * - A growfs operation grabs the m_peraglock in write mode, flushes all the
65 * remaining items from the cache and reallocates the mount point's per-ag
66 * array, resetting all the counters to zero.
67 * - The work queue thread resumes and calls the free function for the element
68 * it started cleaning up earlier. In the process it decrements the
69 * filestreams counter for an AG that now has no references.
70 *
71 * With a shrinkfs feature, the above scenario could panic the system.
72 *
73 * All other uses of the following macros should be protected by either the
74 * m_peraglock held in read mode, or the cache's internal locking exposed by the
75 * interval between a call to xfs_mru_cache_lookup() and a call to
76 * xfs_mru_cache_done(). In addition, the m_peraglock must be held in read mode
77 * when new elements are added to the cache.
78 *
79 * Combined, these locking rules ensure that no associations will ever exist in
80 * the cache that reference per-ag array elements that have since been
81 * reallocated.
82 */
83int
84xfs_filestream_peek_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_read(&pag->pagf_fstrms);
93 xfs_perag_put(pag);
94 return ret;
95}
96
97static int
98xfs_filestream_get_ag(
99 xfs_mount_t *mp,
100 xfs_agnumber_t agno)
101{
102 struct xfs_perag *pag;
103 int ret;
104
105 pag = xfs_perag_get(mp, agno);
106 ret = atomic_inc_return(&pag->pagf_fstrms);
107 xfs_perag_put(pag);
108 return ret;
109}
110
111static void
112xfs_filestream_put_ag(
113 xfs_mount_t *mp,
114 xfs_agnumber_t agno)
115{
116 struct xfs_perag *pag;
117
118 pag = xfs_perag_get(mp, agno);
119 atomic_dec(&pag->pagf_fstrms);
120 xfs_perag_put(pag);
121}
122
123static void
124xfs_fstrm_free_func(
125 struct xfs_mru_cache_elem *mru)
126{
127 struct xfs_fstrm_item *item =
128 container_of(mru, struct xfs_fstrm_item, mru);
129
130 xfs_filestream_put_ag(item->ip->i_mount, item->ag);
131
132 trace_xfs_filestream_free(item->ip, item->ag);
133
134 kmem_free(item);
135}
136
137/*
138 * Scan the AGs starting at startag looking for an AG that isn't in use and has
139 * at least minlen blocks free.
140 */
141static int
142xfs_filestream_pick_ag(
143 struct xfs_inode *ip,
144 xfs_agnumber_t startag,
145 xfs_agnumber_t *agp,
146 int flags,
147 xfs_extlen_t minlen)
148{
149 struct xfs_mount *mp = ip->i_mount;
150 struct xfs_fstrm_item *item;
151 struct xfs_perag *pag;
152 xfs_extlen_t longest, free = 0, minfree, maxfree = 0;
153 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
154 int err, trylock, nscan;
155
156 ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
157
158 /* 2% of an AG's blocks must be free for it to be chosen. */
159 minfree = mp->m_sb.sb_agblocks / 50;
160
161 ag = startag;
162 *agp = NULLAGNUMBER;
163
164 /* For the first pass, don't sleep trying to init the per-AG. */
165 trylock = XFS_ALLOC_FLAG_TRYLOCK;
166
167 for (nscan = 0; 1; nscan++) {
168 trace_xfs_filestream_scan(ip, ag);
169
170 pag = xfs_perag_get(mp, ag);
171
172 if (!pag->pagf_init) {
173 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
174 if (err && !trylock) {
175 xfs_perag_put(pag);
176 return err;
177 }
178 }
179
180 /* Might fail sometimes during the 1st pass with trylock set. */
181 if (!pag->pagf_init)
182 goto next_ag;
183
184 /* Keep track of the AG with the most free blocks. */
185 if (pag->pagf_freeblks > maxfree) {
186 maxfree = pag->pagf_freeblks;
187 max_ag = ag;
188 }
189
190 /*
191 * The AG reference count does two things: it enforces mutual
192 * exclusion when examining the suitability of an AG in this
193 * loop, and it guards against two filestreams being established
194 * in the same AG as each other.
195 */
196 if (xfs_filestream_get_ag(mp, ag) > 1) {
197 xfs_filestream_put_ag(mp, ag);
198 goto next_ag;
199 }
200
201 longest = xfs_alloc_longest_free_extent(mp, pag,
202 xfs_alloc_min_freelist(mp, pag),
203 xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
204 if (((minlen && longest >= minlen) ||
205 (!minlen && pag->pagf_freeblks >= minfree)) &&
206 (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||
207 (flags & XFS_PICK_LOWSPACE))) {
208
209 /* Break out, retaining the reference on the AG. */
210 free = pag->pagf_freeblks;
211 xfs_perag_put(pag);
212 *agp = ag;
213 break;
214 }
215
216 /* Drop the reference on this AG, it's not usable. */
217 xfs_filestream_put_ag(mp, ag);
218next_ag:
219 xfs_perag_put(pag);
220 /* Move to the next AG, wrapping to AG 0 if necessary. */
221 if (++ag >= mp->m_sb.sb_agcount)
222 ag = 0;
223
224 /* If a full pass of the AGs hasn't been done yet, continue. */
225 if (ag != startag)
226 continue;
227
228 /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */
229 if (trylock != 0) {
230 trylock = 0;
231 continue;
232 }
233
234 /* Finally, if lowspace wasn't set, set it for the 3rd pass. */
235 if (!(flags & XFS_PICK_LOWSPACE)) {
236 flags |= XFS_PICK_LOWSPACE;
237 continue;
238 }
239
240 /*
241 * Take the AG with the most free space, regardless of whether
242 * it's already in use by another filestream.
243 */
244 if (max_ag != NULLAGNUMBER) {
245 xfs_filestream_get_ag(mp, max_ag);
246 free = maxfree;
247 *agp = max_ag;
248 break;
249 }
250
251 /* take AG 0 if none matched */
252 trace_xfs_filestream_pick(ip, *agp, free, nscan);
253 *agp = 0;
254 return 0;
255 }
256
257 trace_xfs_filestream_pick(ip, *agp, free, nscan);
258
259 if (*agp == NULLAGNUMBER)
260 return 0;
261
262 err = -ENOMEM;
263 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
264 if (!item)
265 goto out_put_ag;
266
267 item->ag = *agp;
268 item->ip = ip;
269
270 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
271 if (err) {
272 if (err == -EEXIST)
273 err = 0;
274 goto out_free_item;
275 }
276
277 return 0;
278
279out_free_item:
280 kmem_free(item);
281out_put_ag:
282 xfs_filestream_put_ag(mp, *agp);
283 return err;
284}
285
286static struct xfs_inode *
287xfs_filestream_get_parent(
288 struct xfs_inode *ip)
289{
290 struct inode *inode = VFS_I(ip), *dir = NULL;
291 struct dentry *dentry, *parent;
292
293 dentry = d_find_alias(inode);
294 if (!dentry)
295 goto out;
296
297 parent = dget_parent(dentry);
298 if (!parent)
299 goto out_dput;
300
301 dir = igrab(d_inode(parent));
302 dput(parent);
303
304out_dput:
305 dput(dentry);
306out:
307 return dir ? XFS_I(dir) : NULL;
308}
309
310/*
311 * Find the right allocation group for a file, either by finding an
312 * existing file stream or creating a new one.
313 *
314 * Returns NULLAGNUMBER in case of an error.
315 */
316xfs_agnumber_t
317xfs_filestream_lookup_ag(
318 struct xfs_inode *ip)
319{
320 struct xfs_mount *mp = ip->i_mount;
321 struct xfs_inode *pip = NULL;
322 xfs_agnumber_t startag, ag = NULLAGNUMBER;
323 struct xfs_mru_cache_elem *mru;
324
325 ASSERT(S_ISREG(VFS_I(ip)->i_mode));
326
327 pip = xfs_filestream_get_parent(ip);
328 if (!pip)
329 return NULLAGNUMBER;
330
331 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
332 if (mru) {
333 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
334 xfs_mru_cache_done(mp->m_filestream);
335
336 trace_xfs_filestream_lookup(ip, ag);
337 goto out;
338 }
339
340 /*
341 * Set the starting AG using the rotor for inode32, otherwise
342 * use the directory inode's AG.
343 */
344 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
345 xfs_agnumber_t rotorstep = xfs_rotorstep;
346 startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
347 mp->m_agfrotor = (mp->m_agfrotor + 1) %
348 (mp->m_sb.sb_agcount * rotorstep);
349 } else
350 startag = XFS_INO_TO_AGNO(mp, pip->i_ino);
351
352 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
353 ag = NULLAGNUMBER;
354out:
355 IRELE(pip);
356 return ag;
357}
358
359/*
360 * Pick a new allocation group for the current file and its file stream.
361 *
362 * This is called when the allocator can't find a suitable extent in the
363 * current AG, and we have to move the stream into a new AG with more space.
364 */
365int
366xfs_filestream_new_ag(
367 struct xfs_bmalloca *ap,
368 xfs_agnumber_t *agp)
369{
370 struct xfs_inode *ip = ap->ip, *pip;
371 struct xfs_mount *mp = ip->i_mount;
372 xfs_extlen_t minlen = ap->length;
373 xfs_agnumber_t startag = 0;
374 int flags = 0;
375 int err = 0;
376 struct xfs_mru_cache_elem *mru;
377
378 *agp = NULLAGNUMBER;
379
380 pip = xfs_filestream_get_parent(ip);
381 if (!pip)
382 goto exit;
383
384 mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
385 if (mru) {
386 struct xfs_fstrm_item *item =
387 container_of(mru, struct xfs_fstrm_item, mru);
388 startag = (item->ag + 1) % mp->m_sb.sb_agcount;
389 }
390
391 if (xfs_alloc_is_userdata(ap->datatype))
392 flags |= XFS_PICK_USERDATA;
393 if (ap->dfops->dop_low)
394 flags |= XFS_PICK_LOWSPACE;
395
396 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
397
398 /*
399 * Only free the item here so we skip over the old AG earlier.
400 */
401 if (mru)
402 xfs_fstrm_free_func(mru);
403
404 IRELE(pip);
405exit:
406 if (*agp == NULLAGNUMBER)
407 *agp = 0;
408 return err;
409}
410
411void
412xfs_filestream_deassociate(
413 struct xfs_inode *ip)
414{
415 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
416}
417
418int
419xfs_filestream_mount(
420 xfs_mount_t *mp)
421{
422 /*
423 * The filestream timer tunable is currently fixed within the range of
424 * one second to four minutes, with five seconds being the default. The
425 * group count is somewhat arbitrary, but it'd be nice to adhere to the
426 * timer tunable to within about 10 percent. This requires at least 10
427 * groups.
428 */
429 return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10,
430 10, xfs_fstrm_free_func);
431}
432
433void
434xfs_filestream_unmount(
435 xfs_mount_t *mp)
436{
437 xfs_mru_cache_destroy(mp->m_filestream);
438}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
4 * Copyright (c) 2014 Christoph Hellwig.
5 * All Rights Reserved.
6 */
7#include "xfs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_sb.h"
13#include "xfs_mount.h"
14#include "xfs_inode.h"
15#include "xfs_bmap.h"
16#include "xfs_alloc.h"
17#include "xfs_mru_cache.h"
18#include "xfs_trace.h"
19#include "xfs_ag_resv.h"
20#include "xfs_trans.h"
21
22struct xfs_fstrm_item {
23 struct xfs_mru_cache_elem mru;
24 xfs_agnumber_t ag; /* AG in use for this directory */
25};
26
27enum xfs_fstrm_alloc {
28 XFS_PICK_USERDATA = 1,
29 XFS_PICK_LOWSPACE = 2,
30};
31
32/*
33 * Allocation group filestream associations are tracked with per-ag atomic
34 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
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 */
69int
70xfs_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
83static int
84xfs_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
97static void
98xfs_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}
108
109static void
110xfs_fstrm_free_func(
111 void *data,
112 struct xfs_mru_cache_elem *mru)
113{
114 struct xfs_mount *mp = data;
115 struct xfs_fstrm_item *item =
116 container_of(mru, struct xfs_fstrm_item, mru);
117
118 xfs_filestream_put_ag(mp, item->ag);
119 trace_xfs_filestream_free(mp, mru->key, item->ag);
120
121 kmem_free(item);
122}
123
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 */
128static int
129xfs_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)
135{
136 struct xfs_mount *mp = ip->i_mount;
137 struct xfs_fstrm_item *item;
138 struct xfs_perag *pag;
139 xfs_extlen_t longest, free = 0, minfree, maxfree = 0;
140 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
141 int err, trylock, nscan;
142
143 ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
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++) {
155 trace_xfs_filestream_scan(mp, ip->i_ino, ag);
156
157 pag = xfs_perag_get(mp, ag);
158
159 if (!pag->pagf_init) {
160 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
161 if (err && !trylock) {
162 xfs_perag_put(pag);
163 return err;
164 }
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
188 longest = xfs_alloc_longest_free_extent(pag,
189 xfs_alloc_min_freelist(mp, pag),
190 xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
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;
198 xfs_perag_put(pag);
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);
205next_ag:
206 xfs_perag_put(pag);
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);
233 free = maxfree;
234 *agp = max_ag;
235 break;
236 }
237
238 /* take AG 0 if none matched */
239 trace_xfs_filestream_pick(ip, *agp, free, nscan);
240 *agp = 0;
241 return 0;
242 }
243
244 trace_xfs_filestream_pick(ip, *agp, free, nscan);
245
246 if (*agp == NULLAGNUMBER)
247 return 0;
248
249 err = -ENOMEM;
250 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
251 if (!item)
252 goto out_put_ag;
253
254 item->ag = *agp;
255
256 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
257 if (err) {
258 if (err == -EEXIST)
259 err = 0;
260 goto out_free_item;
261 }
262
263 return 0;
264
265out_free_item:
266 kmem_free(item);
267out_put_ag:
268 xfs_filestream_put_ag(mp, *agp);
269 return err;
270}
271
272static struct xfs_inode *
273xfs_filestream_get_parent(
274 struct xfs_inode *ip)
275{
276 struct inode *inode = VFS_I(ip), *dir = NULL;
277 struct dentry *dentry, *parent;
278
279 dentry = d_find_alias(inode);
280 if (!dentry)
281 goto out;
282
283 parent = dget_parent(dentry);
284 if (!parent)
285 goto out_dput;
286
287 dir = igrab(d_inode(parent));
288 dput(parent);
289
290out_dput:
291 dput(dentry);
292out:
293 return dir ? XFS_I(dir) : NULL;
294}
295
296/*
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.
301 */
302xfs_agnumber_t
303xfs_filestream_lookup_ag(
304 struct xfs_inode *ip)
305{
306 struct xfs_mount *mp = ip->i_mount;
307 struct xfs_inode *pip = NULL;
308 xfs_agnumber_t startag, ag = NULLAGNUMBER;
309 struct xfs_mru_cache_elem *mru;
310
311 ASSERT(S_ISREG(VFS_I(ip)->i_mode));
312
313 pip = xfs_filestream_get_parent(ip);
314 if (!pip)
315 return NULLAGNUMBER;
316
317 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
318 if (mru) {
319 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
320 xfs_mru_cache_done(mp->m_filestream);
321
322 trace_xfs_filestream_lookup(mp, ip->i_ino, ag);
323 goto out;
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) {
331 xfs_agnumber_t rotorstep = xfs_rotorstep;
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
338 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
339 ag = NULLAGNUMBER;
340out:
341 xfs_irele(pip);
342 return ag;
343}
344
345/*
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.
350 */
351int
352xfs_filestream_new_ag(
353 struct xfs_bmalloca *ap,
354 xfs_agnumber_t *agp)
355{
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;
360 int flags = 0;
361 int err = 0;
362 struct xfs_mru_cache_elem *mru;
363
364 *agp = NULLAGNUMBER;
365
366 pip = xfs_filestream_get_parent(ip);
367 if (!pip)
368 goto exit;
369
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;
375 }
376
377 if (xfs_alloc_is_userdata(ap->datatype))
378 flags |= XFS_PICK_USERDATA;
379 if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
380 flags |= XFS_PICK_LOWSPACE;
381
382 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
383
384 /*
385 * Only free the item here so we skip over the old AG earlier.
386 */
387 if (mru)
388 xfs_fstrm_free_func(mp, mru);
389
390 xfs_irele(pip);
391exit:
392 if (*agp == NULLAGNUMBER)
393 *agp = 0;
394 return err;
395}
396
397void
398xfs_filestream_deassociate(
399 struct xfs_inode *ip)
400{
401 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
402}
403
404int
405xfs_filestream_mount(
406 xfs_mount_t *mp)
407{
408 /*
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.
414 */
415 return xfs_mru_cache_create(&mp->m_filestream, mp,
416 xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
417}
418
419void
420xfs_filestream_unmount(
421 xfs_mount_t *mp)
422{
423 xfs_mru_cache_destroy(mp->m_filestream);
424}