blob: a2e86e8a0feac8fabf316fb8a790fc805153469a [file] [log] [blame]
David Chinner2a82b8b2007-07-11 11:09:12 +10001/*
2 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +10003 * Copyright (c) 2014 Christoph Hellwig.
David Chinner2a82b8b2007-07-11 11:09:12 +10004 * 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"
Dave Chinnera4fbe6a2013-10-23 10:51:50 +110020#include "xfs_format.h"
Dave Chinner239880e2013-10-23 10:50:10 +110021#include "xfs_log_format.h"
22#include "xfs_trans_resv.h"
Dave Chinner239880e2013-10-23 10:50:10 +110023#include "xfs_sb.h"
24#include "xfs_mount.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100025#include "xfs_inode.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100026#include "xfs_bmap.h"
Dave Chinner68988112013-08-12 20:49:42 +100027#include "xfs_bmap_util.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100028#include "xfs_alloc.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100029#include "xfs_mru_cache.h"
30#include "xfs_filestream.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000031#include "xfs_trace.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100032
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +100033struct 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};
David Chinner2a82b8b2007-07-11 11:09:12 +100043
Christoph Hellwig0664ce82010-07-20 17:31:01 +100044/*
45 * Allocation group filestream associations are tracked with per-ag atomic
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +100046 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
Christoph Hellwig0664ce82010-07-20 17:31:01 +100047 * 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 */
Christoph Hellwigb94acd42014-04-23 07:11:52 +100081int
Christoph Hellwig0664ce82010-07-20 17:31:01 +100082xfs_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}
David Chinner2a82b8b2007-07-11 11:09:12 +1000120
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000121static 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
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000130 trace_xfs_filestream_free(item->ip, item->ag);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000131
Christoph Hellwig1919add2014-04-23 07:11:51 +1000132 kmem_free(item);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000133}
134
David Chinner2a82b8b2007-07-11 11:09:12 +1000135/*
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
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000140xfs_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)
David Chinner2a82b8b2007-07-11 11:09:12 +1000146{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000147 struct xfs_mount *mp = ip->i_mount;
148 struct xfs_fstrm_item *item;
149 struct xfs_perag *pag;
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000150 xfs_extlen_t longest, free = 0, minfree, maxfree = 0;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000151 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000152 int err, trylock, nscan;
153
154 ASSERT(S_ISDIR(ip->i_d.di_mode));
David Chinner2a82b8b2007-07-11 11:09:12 +1000155
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++) {
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000166 trace_xfs_filestream_scan(ip, ag);
167
Dave Chinner4196ac02010-01-11 11:47:42 +0000168 pag = xfs_perag_get(mp, ag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000169
170 if (!pag->pagf_init) {
171 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
Dave Chinner4196ac02010-01-11 11:47:42 +0000172 if (err && !trylock) {
173 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000174 return err;
Dave Chinner4196ac02010-01-11 11:47:42 +0000175 }
David Chinner2a82b8b2007-07-11 11:09:12 +1000176 }
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
Dave Chinner6cc87642009-03-16 08:29:46 +0100199 longest = xfs_alloc_longest_free_extent(mp, pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000200 if (((minlen && longest >= minlen) ||
201 (!minlen && pag->pagf_freeblks >= minfree)) &&
202 (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||
203 (flags & XFS_PICK_LOWSPACE))) {
204
205 /* Break out, retaining the reference on the AG. */
206 free = pag->pagf_freeblks;
Dave Chinner4196ac02010-01-11 11:47:42 +0000207 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000208 *agp = ag;
209 break;
210 }
211
212 /* Drop the reference on this AG, it's not usable. */
213 xfs_filestream_put_ag(mp, ag);
214next_ag:
Dave Chinner4196ac02010-01-11 11:47:42 +0000215 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000216 /* Move to the next AG, wrapping to AG 0 if necessary. */
217 if (++ag >= mp->m_sb.sb_agcount)
218 ag = 0;
219
220 /* If a full pass of the AGs hasn't been done yet, continue. */
221 if (ag != startag)
222 continue;
223
224 /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */
225 if (trylock != 0) {
226 trylock = 0;
227 continue;
228 }
229
230 /* Finally, if lowspace wasn't set, set it for the 3rd pass. */
231 if (!(flags & XFS_PICK_LOWSPACE)) {
232 flags |= XFS_PICK_LOWSPACE;
233 continue;
234 }
235
236 /*
237 * Take the AG with the most free space, regardless of whether
238 * it's already in use by another filestream.
239 */
240 if (max_ag != NULLAGNUMBER) {
241 xfs_filestream_get_ag(mp, max_ag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000242 free = maxfree;
243 *agp = max_ag;
244 break;
245 }
246
247 /* take AG 0 if none matched */
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000248 trace_xfs_filestream_pick(ip, *agp, free, nscan);
David Chinner2a82b8b2007-07-11 11:09:12 +1000249 *agp = 0;
250 return 0;
251 }
252
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000253 trace_xfs_filestream_pick(ip, *agp, free, nscan);
David Chinner2a82b8b2007-07-11 11:09:12 +1000254
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000255 if (*agp == NULLAGNUMBER)
David Chinner2a82b8b2007-07-11 11:09:12 +1000256 return 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000257
Dave Chinner24513372014-06-25 14:58:08 +1000258 err = -ENOMEM;
Christoph Hellwig1919add2014-04-23 07:11:51 +1000259 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
David Chinner2a82b8b2007-07-11 11:09:12 +1000260 if (!item)
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000261 goto out_put_ag;
David Chinner2a82b8b2007-07-11 11:09:12 +1000262
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000263 item->ag = *agp;
David Chinner2a82b8b2007-07-11 11:09:12 +1000264 item->ip = ip;
David Chinner2a82b8b2007-07-11 11:09:12 +1000265
Christoph Hellwig22328d72014-04-23 07:11:51 +1000266 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
David Chinner2a82b8b2007-07-11 11:09:12 +1000267 if (err) {
Dave Chinner24513372014-06-25 14:58:08 +1000268 if (err == -EEXIST)
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000269 err = 0;
270 goto out_free_item;
David Chinner2a82b8b2007-07-11 11:09:12 +1000271 }
272
David Chinner2a82b8b2007-07-11 11:09:12 +1000273 return 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000274
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000275out_free_item:
Christoph Hellwig1919add2014-04-23 07:11:51 +1000276 kmem_free(item);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000277out_put_ag:
278 xfs_filestream_put_ag(mp, *agp);
David Chinner2a82b8b2007-07-11 11:09:12 +1000279 return err;
280}
281
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000282static struct xfs_inode *
283xfs_filestream_get_parent(
284 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000285{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000286 struct inode *inode = VFS_I(ip), *dir = NULL;
287 struct dentry *dentry, *parent;
288
289 dentry = d_find_alias(inode);
290 if (!dentry)
291 goto out;
292
293 parent = dget_parent(dentry);
294 if (!parent)
295 goto out_dput;
296
297 dir = igrab(parent->d_inode);
298 dput(parent);
299
300out_dput:
301 dput(dentry);
302out:
303 return dir ? XFS_I(dir) : NULL;
David Chinner2a82b8b2007-07-11 11:09:12 +1000304}
305
306/*
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000307 * Find the right allocation group for a file, either by finding an
308 * existing file stream or creating a new one.
309 *
310 * Returns NULLAGNUMBER in case of an error.
David Chinner2a82b8b2007-07-11 11:09:12 +1000311 */
312xfs_agnumber_t
313xfs_filestream_lookup_ag(
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000314 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000315{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000316 struct xfs_mount *mp = ip->i_mount;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000317 struct xfs_inode *pip = NULL;
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000318 xfs_agnumber_t startag, ag = NULLAGNUMBER;
Christoph Hellwig22328d72014-04-23 07:11:51 +1000319 struct xfs_mru_cache_elem *mru;
David Chinner2a82b8b2007-07-11 11:09:12 +1000320
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000321 ASSERT(S_ISREG(ip->i_d.di_mode));
David Chinner2a82b8b2007-07-11 11:09:12 +1000322
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000323 pip = xfs_filestream_get_parent(ip);
324 if (!pip)
325 goto out;
David Chinner2a82b8b2007-07-11 11:09:12 +1000326
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000327 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
Christoph Hellwig22328d72014-04-23 07:11:51 +1000328 if (mru) {
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000329 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
Christoph Hellwig22328d72014-04-23 07:11:51 +1000330 xfs_mru_cache_done(mp->m_filestream);
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000331
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000332 trace_xfs_filestream_lookup(ip, ag);
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000333 goto out;
David Chinner2a82b8b2007-07-11 11:09:12 +1000334 }
335
336 /*
337 * Set the starting AG using the rotor for inode32, otherwise
338 * use the directory inode's AG.
339 */
340 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000341 xfs_agnumber_t rotorstep = xfs_rotorstep;
David Chinner2a82b8b2007-07-11 11:09:12 +1000342 startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
343 mp->m_agfrotor = (mp->m_agfrotor + 1) %
344 (mp->m_sb.sb_agcount * rotorstep);
345 } else
346 startag = XFS_INO_TO_AGNO(mp, pip->i_ino);
347
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000348 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
349 ag = NULLAGNUMBER;
350out:
351 IRELE(pip);
352 return ag;
David Chinner2a82b8b2007-07-11 11:09:12 +1000353}
354
355/*
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000356 * Pick a new allocation group for the current file and its file stream.
357 *
358 * This is called when the allocator can't find a suitable extent in the
359 * current AG, and we have to move the stream into a new AG with more space.
David Chinner2a82b8b2007-07-11 11:09:12 +1000360 */
361int
362xfs_filestream_new_ag(
Dave Chinner68988112013-08-12 20:49:42 +1000363 struct xfs_bmalloca *ap,
364 xfs_agnumber_t *agp)
David Chinner2a82b8b2007-07-11 11:09:12 +1000365{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000366 struct xfs_inode *ip = ap->ip, *pip;
367 struct xfs_mount *mp = ip->i_mount;
368 xfs_extlen_t minlen = ap->length;
369 xfs_agnumber_t startag = 0;
370 int flags, err = 0;
371 struct xfs_mru_cache_elem *mru;
David Chinner2a82b8b2007-07-11 11:09:12 +1000372
David Chinner2a82b8b2007-07-11 11:09:12 +1000373 *agp = NULLAGNUMBER;
374
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000375 pip = xfs_filestream_get_parent(ip);
376 if (!pip)
377 goto exit;
378
379 mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
Christoph Hellwig22328d72014-04-23 07:11:51 +1000380 if (mru) {
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000381 struct xfs_fstrm_item *item =
382 container_of(mru, struct xfs_fstrm_item, mru);
383 startag = (item->ag + 1) % mp->m_sb.sb_agcount;
David Chinner2a82b8b2007-07-11 11:09:12 +1000384 }
385
David Chinner2a82b8b2007-07-11 11:09:12 +1000386 flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
Dave Chinner0937e0f2011-09-18 20:40:57 +0000387 (ap->flist->xbf_low ? XFS_PICK_LOWSPACE : 0);
David Chinner2a82b8b2007-07-11 11:09:12 +1000388
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000389 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
David Chinner2a82b8b2007-07-11 11:09:12 +1000390
391 /*
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000392 * Only free the item here so we skip over the old AG earlier.
David Chinner2a82b8b2007-07-11 11:09:12 +1000393 */
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000394 if (mru)
395 xfs_fstrm_free_func(mru);
David Chinner2a82b8b2007-07-11 11:09:12 +1000396
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000397 IRELE(pip);
David Chinner2a82b8b2007-07-11 11:09:12 +1000398exit:
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000399 if (*agp == NULLAGNUMBER)
David Chinner2a82b8b2007-07-11 11:09:12 +1000400 *agp = 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000401 return err;
402}
403
David Chinner2a82b8b2007-07-11 11:09:12 +1000404void
405xfs_filestream_deassociate(
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000406 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000407{
Christoph Hellwig22328d72014-04-23 07:11:51 +1000408 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
David Chinner2a82b8b2007-07-11 11:09:12 +1000409}
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000410
411int
412xfs_filestream_mount(
413 xfs_mount_t *mp)
414{
415 /*
416 * The filestream timer tunable is currently fixed within the range of
417 * one second to four minutes, with five seconds being the default. The
418 * group count is somewhat arbitrary, but it'd be nice to adhere to the
419 * timer tunable to within about 10 percent. This requires at least 10
420 * groups.
421 */
422 return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10,
423 10, xfs_fstrm_free_func);
424}
425
426void
427xfs_filestream_unmount(
428 xfs_mount_t *mp)
429{
430 xfs_mru_cache_destroy(mp->m_filestream);
431}