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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 xfs_agnumber_t ag; /* AG in use for this directory */
38};
39
40enum xfs_fstrm_alloc {
41 XFS_PICK_USERDATA = 1,
42 XFS_PICK_LOWSPACE = 2,
43};
44
45/*
46 * Allocation group filestream associations are tracked with per-ag atomic
47 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
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 */
82int
83xfs_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
96static int
97xfs_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
110static void
111xfs_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}
121
122static void
123xfs_fstrm_free_func(
124 void *data,
125 struct xfs_mru_cache_elem *mru)
126{
127 struct xfs_mount *mp = data;
128 struct xfs_fstrm_item *item =
129 container_of(mru, struct xfs_fstrm_item, mru);
130
131 xfs_filestream_put_ag(mp, item->ag);
132 trace_xfs_filestream_free(mp, mru->key, 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(mp, ip->i_ino, 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(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
269 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
270 if (err) {
271 if (err == -EEXIST)
272 err = 0;
273 goto out_free_item;
274 }
275
276 return 0;
277
278out_free_item:
279 kmem_free(item);
280out_put_ag:
281 xfs_filestream_put_ag(mp, *agp);
282 return err;
283}
284
285static struct xfs_inode *
286xfs_filestream_get_parent(
287 struct xfs_inode *ip)
288{
289 struct inode *inode = VFS_I(ip), *dir = NULL;
290 struct dentry *dentry, *parent;
291
292 dentry = d_find_alias(inode);
293 if (!dentry)
294 goto out;
295
296 parent = dget_parent(dentry);
297 if (!parent)
298 goto out_dput;
299
300 dir = igrab(d_inode(parent));
301 dput(parent);
302
303out_dput:
304 dput(dentry);
305out:
306 return dir ? XFS_I(dir) : NULL;
307}
308
309/*
310 * Find the right allocation group for a file, either by finding an
311 * existing file stream or creating a new one.
312 *
313 * Returns NULLAGNUMBER in case of an error.
314 */
315xfs_agnumber_t
316xfs_filestream_lookup_ag(
317 struct xfs_inode *ip)
318{
319 struct xfs_mount *mp = ip->i_mount;
320 struct xfs_inode *pip = NULL;
321 xfs_agnumber_t startag, ag = NULLAGNUMBER;
322 struct xfs_mru_cache_elem *mru;
323
324 ASSERT(S_ISREG(VFS_I(ip)->i_mode));
325
326 pip = xfs_filestream_get_parent(ip);
327 if (!pip)
328 return NULLAGNUMBER;
329
330 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
331 if (mru) {
332 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
333 xfs_mru_cache_done(mp->m_filestream);
334
335 trace_xfs_filestream_lookup(mp, ip->i_ino, ag);
336 goto out;
337 }
338
339 /*
340 * Set the starting AG using the rotor for inode32, otherwise
341 * use the directory inode's AG.
342 */
343 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
344 xfs_agnumber_t rotorstep = xfs_rotorstep;
345 startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
346 mp->m_agfrotor = (mp->m_agfrotor + 1) %
347 (mp->m_sb.sb_agcount * rotorstep);
348 } else
349 startag = XFS_INO_TO_AGNO(mp, pip->i_ino);
350
351 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
352 ag = NULLAGNUMBER;
353out:
354 IRELE(pip);
355 return ag;
356}
357
358/*
359 * Pick a new allocation group for the current file and its file stream.
360 *
361 * This is called when the allocator can't find a suitable extent in the
362 * current AG, and we have to move the stream into a new AG with more space.
363 */
364int
365xfs_filestream_new_ag(
366 struct xfs_bmalloca *ap,
367 xfs_agnumber_t *agp)
368{
369 struct xfs_inode *ip = ap->ip, *pip;
370 struct xfs_mount *mp = ip->i_mount;
371 xfs_extlen_t minlen = ap->length;
372 xfs_agnumber_t startag = 0;
373 int flags = 0;
374 int err = 0;
375 struct xfs_mru_cache_elem *mru;
376
377 *agp = NULLAGNUMBER;
378
379 pip = xfs_filestream_get_parent(ip);
380 if (!pip)
381 goto exit;
382
383 mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
384 if (mru) {
385 struct xfs_fstrm_item *item =
386 container_of(mru, struct xfs_fstrm_item, mru);
387 startag = (item->ag + 1) % mp->m_sb.sb_agcount;
388 }
389
390 if (xfs_alloc_is_userdata(ap->datatype))
391 flags |= XFS_PICK_USERDATA;
392 if (ap->dfops->dop_low)
393 flags |= XFS_PICK_LOWSPACE;
394
395 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
396
397 /*
398 * Only free the item here so we skip over the old AG earlier.
399 */
400 if (mru)
401 xfs_fstrm_free_func(mp, mru);
402
403 IRELE(pip);
404exit:
405 if (*agp == NULLAGNUMBER)
406 *agp = 0;
407 return err;
408}
409
410void
411xfs_filestream_deassociate(
412 struct xfs_inode *ip)
413{
414 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
415}
416
417int
418xfs_filestream_mount(
419 xfs_mount_t *mp)
420{
421 /*
422 * The filestream timer tunable is currently fixed within the range of
423 * one second to four minutes, with five seconds being the default. The
424 * group count is somewhat arbitrary, but it'd be nice to adhere to the
425 * timer tunable to within about 10 percent. This requires at least 10
426 * groups.
427 */
428 return xfs_mru_cache_create(&mp->m_filestream, mp,
429 xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
430}
431
432void
433xfs_filestream_unmount(
434 xfs_mount_t *mp)
435{
436 xfs_mru_cache_destroy(mp->m_filestream);
437}
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}