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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_mount.h"
13#include "xfs_inode.h"
14#include "xfs_bmap.h"
15#include "xfs_bmap_util.h"
16#include "xfs_alloc.h"
17#include "xfs_mru_cache.h"
18#include "xfs_trace.h"
19#include "xfs_ag.h"
20#include "xfs_ag_resv.h"
21#include "xfs_trans.h"
22#include "xfs_filestream.h"
23
24struct xfs_fstrm_item {
25 struct xfs_mru_cache_elem mru;
26 struct xfs_perag *pag; /* AG in use for this directory */
27};
28
29enum xfs_fstrm_alloc {
30 XFS_PICK_USERDATA = 1,
31 XFS_PICK_LOWSPACE = 2,
32};
33
34static void
35xfs_fstrm_free_func(
36 void *data,
37 struct xfs_mru_cache_elem *mru)
38{
39 struct xfs_fstrm_item *item =
40 container_of(mru, struct xfs_fstrm_item, mru);
41 struct xfs_perag *pag = item->pag;
42
43 trace_xfs_filestream_free(pag, mru->key);
44 atomic_dec(&pag->pagf_fstrms);
45 xfs_perag_rele(pag);
46
47 kfree(item);
48}
49
50/*
51 * Scan the AGs starting at start_agno looking for an AG that isn't in use and
52 * has at least minlen blocks free. If no AG is found to match the allocation
53 * requirements, pick the AG with the most free space in it.
54 */
55static int
56xfs_filestream_pick_ag(
57 struct xfs_alloc_arg *args,
58 xfs_ino_t pino,
59 xfs_agnumber_t start_agno,
60 int flags,
61 xfs_extlen_t *longest)
62{
63 struct xfs_mount *mp = args->mp;
64 struct xfs_perag *pag;
65 struct xfs_perag *max_pag = NULL;
66 xfs_extlen_t minlen = *longest;
67 xfs_extlen_t minfree, maxfree = 0;
68 xfs_agnumber_t agno;
69 bool first_pass = true;
70
71 /* 2% of an AG's blocks must be free for it to be chosen. */
72 minfree = mp->m_sb.sb_agblocks / 50;
73
74restart:
75 for_each_perag_wrap(mp, start_agno, agno, pag) {
76 int err;
77
78 trace_xfs_filestream_scan(pag, pino);
79
80 *longest = 0;
81 err = xfs_bmap_longest_free_extent(pag, NULL, longest);
82 if (err) {
83 if (err == -EAGAIN) {
84 /* Couldn't lock the AGF, skip this AG. */
85 err = 0;
86 continue;
87 }
88 xfs_perag_rele(pag);
89 if (max_pag)
90 xfs_perag_rele(max_pag);
91 return err;
92 }
93
94 /* Keep track of the AG with the most free blocks. */
95 if (pag->pagf_freeblks > maxfree) {
96 maxfree = pag->pagf_freeblks;
97 if (max_pag)
98 xfs_perag_rele(max_pag);
99 atomic_inc(&pag_group(pag)->xg_active_ref);
100 max_pag = pag;
101 }
102
103 /*
104 * The AG reference count does two things: it enforces mutual
105 * exclusion when examining the suitability of an AG in this
106 * loop, and it guards against two filestreams being established
107 * in the same AG as each other.
108 */
109 if (atomic_inc_return(&pag->pagf_fstrms) <= 1) {
110 if (((minlen && *longest >= minlen) ||
111 (!minlen && pag->pagf_freeblks >= minfree)) &&
112 (!xfs_perag_prefers_metadata(pag) ||
113 !(flags & XFS_PICK_USERDATA) ||
114 (flags & XFS_PICK_LOWSPACE))) {
115 /* Break out, retaining the reference on the AG. */
116 if (max_pag)
117 xfs_perag_rele(max_pag);
118 goto done;
119 }
120 }
121
122 /* Drop the reference on this AG, it's not usable. */
123 atomic_dec(&pag->pagf_fstrms);
124 }
125
126 /*
127 * Allow a second pass to give xfs_bmap_longest_free_extent() another
128 * attempt at locking AGFs that it might have skipped over before we
129 * fail.
130 */
131 if (first_pass) {
132 first_pass = false;
133 goto restart;
134 }
135
136 /*
137 * We must be low on data space, so run a final lowspace optimised
138 * selection pass if we haven't already.
139 */
140 if (!(flags & XFS_PICK_LOWSPACE)) {
141 flags |= XFS_PICK_LOWSPACE;
142 goto restart;
143 }
144
145 /*
146 * No unassociated AGs are available, so select the AG with the most
147 * free space, regardless of whether it's already in use by another
148 * filestream. It none suit, just use whatever AG we can grab.
149 */
150 if (!max_pag) {
151 for_each_perag_wrap(args->mp, 0, start_agno, pag) {
152 max_pag = pag;
153 break;
154 }
155
156 /* Bail if there are no AGs at all to select from. */
157 if (!max_pag)
158 return -ENOSPC;
159 }
160
161 pag = max_pag;
162 atomic_inc(&pag->pagf_fstrms);
163done:
164 trace_xfs_filestream_pick(pag, pino);
165 args->pag = pag;
166 return 0;
167}
168
169static struct xfs_inode *
170xfs_filestream_get_parent(
171 struct xfs_inode *ip)
172{
173 struct inode *inode = VFS_I(ip), *dir = NULL;
174 struct dentry *dentry, *parent;
175
176 dentry = d_find_alias(inode);
177 if (!dentry)
178 goto out;
179
180 parent = dget_parent(dentry);
181 if (!parent)
182 goto out_dput;
183
184 dir = igrab(d_inode(parent));
185 dput(parent);
186
187out_dput:
188 dput(dentry);
189out:
190 return dir ? XFS_I(dir) : NULL;
191}
192
193/*
194 * Lookup the mru cache for an existing association. If one exists and we can
195 * use it, return with an active perag reference indicating that the allocation
196 * will proceed with that association.
197 *
198 * If we have no association, or we cannot use the current one and have to
199 * destroy it, return with longest = 0 to tell the caller to create a new
200 * association.
201 */
202static int
203xfs_filestream_lookup_association(
204 struct xfs_bmalloca *ap,
205 struct xfs_alloc_arg *args,
206 xfs_ino_t pino,
207 xfs_extlen_t *longest)
208{
209 struct xfs_mount *mp = args->mp;
210 struct xfs_perag *pag;
211 struct xfs_mru_cache_elem *mru;
212 int error = 0;
213
214 *longest = 0;
215 mru = xfs_mru_cache_lookup(mp->m_filestream, pino);
216 if (!mru)
217 return 0;
218 /*
219 * Grab the pag and take an extra active reference for the caller whilst
220 * the mru item cannot go away. This means we'll pin the perag with
221 * the reference we get here even if the filestreams association is torn
222 * down immediately after we mark the lookup as done.
223 */
224 pag = container_of(mru, struct xfs_fstrm_item, mru)->pag;
225 atomic_inc(&pag_group(pag)->xg_active_ref);
226 xfs_mru_cache_done(mp->m_filestream);
227
228 trace_xfs_filestream_lookup(pag, ap->ip->i_ino);
229
230 ap->blkno = xfs_agbno_to_fsb(pag, 0);
231 xfs_bmap_adjacent(ap);
232
233 /*
234 * If there is very little free space before we start a filestreams
235 * allocation, we're almost guaranteed to fail to find a large enough
236 * free space available so just use the cached AG.
237 */
238 if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
239 *longest = 1;
240 goto out_done;
241 }
242
243 error = xfs_bmap_longest_free_extent(pag, args->tp, longest);
244 if (error == -EAGAIN)
245 error = 0;
246 if (error || *longest < args->maxlen) {
247 /* We aren't going to use this perag */
248 *longest = 0;
249 xfs_perag_rele(pag);
250 return error;
251 }
252
253out_done:
254 args->pag = pag;
255 return 0;
256}
257
258static int
259xfs_filestream_create_association(
260 struct xfs_bmalloca *ap,
261 struct xfs_alloc_arg *args,
262 xfs_ino_t pino,
263 xfs_extlen_t *longest)
264{
265 struct xfs_mount *mp = args->mp;
266 struct xfs_mru_cache_elem *mru;
267 struct xfs_fstrm_item *item;
268 xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, pino);
269 int flags = 0;
270 int error;
271
272 /* Changing parent AG association now, so remove the existing one. */
273 mru = xfs_mru_cache_remove(mp->m_filestream, pino);
274 if (mru) {
275 struct xfs_fstrm_item *item =
276 container_of(mru, struct xfs_fstrm_item, mru);
277
278 agno = (pag_agno(item->pag) + 1) % mp->m_sb.sb_agcount;
279 xfs_fstrm_free_func(mp, mru);
280 } else if (xfs_is_inode32(mp)) {
281 xfs_agnumber_t rotorstep = xfs_rotorstep;
282
283 agno = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
284 mp->m_agfrotor = (mp->m_agfrotor + 1) %
285 (mp->m_sb.sb_agcount * rotorstep);
286 }
287
288 ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
289 xfs_bmap_adjacent(ap);
290
291 if (ap->datatype & XFS_ALLOC_USERDATA)
292 flags |= XFS_PICK_USERDATA;
293 if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
294 flags |= XFS_PICK_LOWSPACE;
295
296 *longest = ap->length;
297 error = xfs_filestream_pick_ag(args, pino, agno, flags, longest);
298 if (error)
299 return error;
300
301 /*
302 * We are going to use this perag now, so create an assoication for it.
303 * xfs_filestream_pick_ag() has already bumped the perag fstrms counter
304 * for us, so all we need to do here is take another active reference to
305 * the perag for the cached association.
306 *
307 * If we fail to store the association, we need to drop the fstrms
308 * counter as well as drop the perag reference we take here for the
309 * item. We do not need to return an error for this failure - as long as
310 * we return a referenced AG, the allocation can still go ahead just
311 * fine.
312 */
313 item = kmalloc(sizeof(*item), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
314 if (!item)
315 goto out_put_fstrms;
316
317 atomic_inc(&pag_group(args->pag)->xg_active_ref);
318 item->pag = args->pag;
319 error = xfs_mru_cache_insert(mp->m_filestream, pino, &item->mru);
320 if (error)
321 goto out_free_item;
322 return 0;
323
324out_free_item:
325 xfs_perag_rele(item->pag);
326 kfree(item);
327out_put_fstrms:
328 atomic_dec(&args->pag->pagf_fstrms);
329 return 0;
330}
331
332/*
333 * Search for an allocation group with a single extent large enough for
334 * the request. First we look for an existing association and use that if it
335 * is found. Otherwise, we create a new association by selecting an AG that fits
336 * the allocation criteria.
337 *
338 * We return with a referenced perag in args->pag to indicate which AG we are
339 * allocating into or an error with no references held.
340 */
341int
342xfs_filestream_select_ag(
343 struct xfs_bmalloca *ap,
344 struct xfs_alloc_arg *args,
345 xfs_extlen_t *longest)
346{
347 struct xfs_inode *pip;
348 xfs_ino_t ino = 0;
349 int error = 0;
350
351 *longest = 0;
352 args->total = ap->total;
353 pip = xfs_filestream_get_parent(ap->ip);
354 if (pip) {
355 ino = pip->i_ino;
356 error = xfs_filestream_lookup_association(ap, args, ino,
357 longest);
358 xfs_irele(pip);
359 if (error)
360 return error;
361 if (*longest >= args->maxlen)
362 goto out_select;
363 if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
364 goto out_select;
365 }
366
367 error = xfs_filestream_create_association(ap, args, ino, longest);
368 if (error)
369 return error;
370
371out_select:
372 ap->blkno = xfs_agbno_to_fsb(args->pag, 0);
373 return 0;
374}
375
376void
377xfs_filestream_deassociate(
378 struct xfs_inode *ip)
379{
380 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
381}
382
383int
384xfs_filestream_mount(
385 xfs_mount_t *mp)
386{
387 /*
388 * The filestream timer tunable is currently fixed within the range of
389 * one second to four minutes, with five seconds being the default. The
390 * group count is somewhat arbitrary, but it'd be nice to adhere to the
391 * timer tunable to within about 10 percent. This requires at least 10
392 * groups.
393 */
394 return xfs_mru_cache_create(&mp->m_filestream, mp,
395 xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
396}
397
398void
399xfs_filestream_unmount(
400 xfs_mount_t *mp)
401{
402 xfs_mru_cache_destroy(mp->m_filestream);
403}
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_inode.h"
26#include "xfs_bmap.h"
27#include "xfs_bmap_util.h"
28#include "xfs_alloc.h"
29#include "xfs_mru_cache.h"
30#include "xfs_filestream.h"
31#include "xfs_trace.h"
32
33struct 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
39enum xfs_fstrm_alloc {
40 XFS_PICK_USERDATA = 1,
41 XFS_PICK_LOWSPACE = 2,
42};
43
44/*
45 * Allocation group filestream associations are tracked with per-ag atomic
46 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
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 */
81int
82xfs_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
95static int
96xfs_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
109static void
110xfs_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}
120
121static void
122xfs_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
130 trace_xfs_filestream_free(item->ip, item->ag);
131
132 kmem_free(item);
133}
134
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 */
139static int
140xfs_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)
146{
147 struct xfs_mount *mp = ip->i_mount;
148 struct xfs_fstrm_item *item;
149 struct xfs_perag *pag;
150 xfs_extlen_t longest, free = 0, minfree, maxfree = 0;
151 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
152 int err, trylock, nscan;
153
154 ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
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++) {
166 trace_xfs_filestream_scan(ip, ag);
167
168 pag = xfs_perag_get(mp, ag);
169
170 if (!pag->pagf_init) {
171 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
172 if (err && !trylock) {
173 xfs_perag_put(pag);
174 return err;
175 }
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
199 longest = xfs_alloc_longest_free_extent(mp, pag,
200 xfs_alloc_min_freelist(mp, pag));
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;
208 xfs_perag_put(pag);
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);
215next_ag:
216 xfs_perag_put(pag);
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);
243 free = maxfree;
244 *agp = max_ag;
245 break;
246 }
247
248 /* take AG 0 if none matched */
249 trace_xfs_filestream_pick(ip, *agp, free, nscan);
250 *agp = 0;
251 return 0;
252 }
253
254 trace_xfs_filestream_pick(ip, *agp, free, nscan);
255
256 if (*agp == NULLAGNUMBER)
257 return 0;
258
259 err = -ENOMEM;
260 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
261 if (!item)
262 goto out_put_ag;
263
264 item->ag = *agp;
265 item->ip = ip;
266
267 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
268 if (err) {
269 if (err == -EEXIST)
270 err = 0;
271 goto out_free_item;
272 }
273
274 return 0;
275
276out_free_item:
277 kmem_free(item);
278out_put_ag:
279 xfs_filestream_put_ag(mp, *agp);
280 return err;
281}
282
283static struct xfs_inode *
284xfs_filestream_get_parent(
285 struct xfs_inode *ip)
286{
287 struct inode *inode = VFS_I(ip), *dir = NULL;
288 struct dentry *dentry, *parent;
289
290 dentry = d_find_alias(inode);
291 if (!dentry)
292 goto out;
293
294 parent = dget_parent(dentry);
295 if (!parent)
296 goto out_dput;
297
298 dir = igrab(d_inode(parent));
299 dput(parent);
300
301out_dput:
302 dput(dentry);
303out:
304 return dir ? XFS_I(dir) : NULL;
305}
306
307/*
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.
312 */
313xfs_agnumber_t
314xfs_filestream_lookup_ag(
315 struct xfs_inode *ip)
316{
317 struct xfs_mount *mp = ip->i_mount;
318 struct xfs_inode *pip = NULL;
319 xfs_agnumber_t startag, ag = NULLAGNUMBER;
320 struct xfs_mru_cache_elem *mru;
321
322 ASSERT(S_ISREG(VFS_I(ip)->i_mode));
323
324 pip = xfs_filestream_get_parent(ip);
325 if (!pip)
326 return NULLAGNUMBER;
327
328 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
329 if (mru) {
330 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
331 xfs_mru_cache_done(mp->m_filestream);
332
333 trace_xfs_filestream_lookup(ip, ag);
334 goto out;
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) {
342 xfs_agnumber_t rotorstep = xfs_rotorstep;
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
349 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
350 ag = NULLAGNUMBER;
351out:
352 IRELE(pip);
353 return ag;
354}
355
356/*
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.
361 */
362int
363xfs_filestream_new_ag(
364 struct xfs_bmalloca *ap,
365 xfs_agnumber_t *agp)
366{
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;
373
374 *agp = NULLAGNUMBER;
375
376 pip = xfs_filestream_get_parent(ip);
377 if (!pip)
378 goto exit;
379
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;
385 }
386
387 flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
388 (ap->flist->xbf_low ? XFS_PICK_LOWSPACE : 0);
389
390 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
391
392 /*
393 * Only free the item here so we skip over the old AG earlier.
394 */
395 if (mru)
396 xfs_fstrm_free_func(mru);
397
398 IRELE(pip);
399exit:
400 if (*agp == NULLAGNUMBER)
401 *agp = 0;
402 return err;
403}
404
405void
406xfs_filestream_deassociate(
407 struct xfs_inode *ip)
408{
409 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
410}
411
412int
413xfs_filestream_mount(
414 xfs_mount_t *mp)
415{
416 /*
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.
422 */
423 return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10,
424 10, xfs_fstrm_free_func);
425}
426
427void
428xfs_filestream_unmount(
429 xfs_mount_t *mp)
430{
431 xfs_mru_cache_destroy(mp->m_filestream);
432}