blob: 4a33a3304369109f2864bf97362962865f56c930 [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"
Darrick J. Wong3ab78df2016-08-03 11:15:38 +100025#include "xfs_defer.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100026#include "xfs_inode.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100027#include "xfs_bmap.h"
Dave Chinner68988112013-08-12 20:49:42 +100028#include "xfs_bmap_util.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100029#include "xfs_alloc.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100030#include "xfs_mru_cache.h"
31#include "xfs_filestream.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000032#include "xfs_trace.h"
David Chinner2a82b8b2007-07-11 11:09:12 +100033
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +100034struct 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
40enum xfs_fstrm_alloc {
41 XFS_PICK_USERDATA = 1,
42 XFS_PICK_LOWSPACE = 2,
43};
David Chinner2a82b8b2007-07-11 11:09:12 +100044
Christoph Hellwig0664ce82010-07-20 17:31:01 +100045/*
46 * Allocation group filestream associations are tracked with per-ag atomic
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +100047 * counters. These counters allow xfs_filestream_pick_ag() to tell whether a
Christoph Hellwig0664ce82010-07-20 17:31:01 +100048 * 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 */
Christoph Hellwigb94acd42014-04-23 07:11:52 +100082int
Christoph Hellwig0664ce82010-07-20 17:31:01 +100083xfs_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}
David Chinner2a82b8b2007-07-11 11:09:12 +1000121
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000122static void
123xfs_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
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000131 trace_xfs_filestream_free(item->ip, item->ag);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000132
Christoph Hellwig1919add2014-04-23 07:11:51 +1000133 kmem_free(item);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000134}
135
David Chinner2a82b8b2007-07-11 11:09:12 +1000136/*
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 */
140static int
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000141xfs_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)
David Chinner2a82b8b2007-07-11 11:09:12 +1000147{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000148 struct xfs_mount *mp = ip->i_mount;
149 struct xfs_fstrm_item *item;
150 struct xfs_perag *pag;
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000151 xfs_extlen_t longest, free = 0, minfree, maxfree = 0;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000152 xfs_agnumber_t ag, max_ag = NULLAGNUMBER;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000153 int err, trylock, nscan;
154
Dave Chinnerc19b3b052016-02-09 16:54:58 +1100155 ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
David Chinner2a82b8b2007-07-11 11:09:12 +1000156
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++) {
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000167 trace_xfs_filestream_scan(ip, ag);
168
Dave Chinner4196ac02010-01-11 11:47:42 +0000169 pag = xfs_perag_get(mp, ag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000170
171 if (!pag->pagf_init) {
172 err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
Dave Chinner4196ac02010-01-11 11:47:42 +0000173 if (err && !trylock) {
174 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000175 return err;
Dave Chinner4196ac02010-01-11 11:47:42 +0000176 }
David Chinner2a82b8b2007-07-11 11:09:12 +1000177 }
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
Dave Chinner50adbcb2015-06-22 10:04:31 +1000200 longest = xfs_alloc_longest_free_extent(mp, pag,
Dave Chinner496817b2015-06-22 10:13:30 +1000201 xfs_alloc_min_freelist(mp, pag));
David Chinner2a82b8b2007-07-11 11:09:12 +1000202 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;
Dave Chinner4196ac02010-01-11 11:47:42 +0000209 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000210 *agp = ag;
211 break;
212 }
213
214 /* Drop the reference on this AG, it's not usable. */
215 xfs_filestream_put_ag(mp, ag);
216next_ag:
Dave Chinner4196ac02010-01-11 11:47:42 +0000217 xfs_perag_put(pag);
David Chinner2a82b8b2007-07-11 11:09:12 +1000218 /* 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);
David Chinner2a82b8b2007-07-11 11:09:12 +1000244 free = maxfree;
245 *agp = max_ag;
246 break;
247 }
248
249 /* take AG 0 if none matched */
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000250 trace_xfs_filestream_pick(ip, *agp, free, nscan);
David Chinner2a82b8b2007-07-11 11:09:12 +1000251 *agp = 0;
252 return 0;
253 }
254
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000255 trace_xfs_filestream_pick(ip, *agp, free, nscan);
David Chinner2a82b8b2007-07-11 11:09:12 +1000256
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000257 if (*agp == NULLAGNUMBER)
David Chinner2a82b8b2007-07-11 11:09:12 +1000258 return 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000259
Dave Chinner24513372014-06-25 14:58:08 +1000260 err = -ENOMEM;
Christoph Hellwig1919add2014-04-23 07:11:51 +1000261 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
David Chinner2a82b8b2007-07-11 11:09:12 +1000262 if (!item)
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000263 goto out_put_ag;
David Chinner2a82b8b2007-07-11 11:09:12 +1000264
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000265 item->ag = *agp;
David Chinner2a82b8b2007-07-11 11:09:12 +1000266 item->ip = ip;
David Chinner2a82b8b2007-07-11 11:09:12 +1000267
Christoph Hellwig22328d72014-04-23 07:11:51 +1000268 err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
David Chinner2a82b8b2007-07-11 11:09:12 +1000269 if (err) {
Dave Chinner24513372014-06-25 14:58:08 +1000270 if (err == -EEXIST)
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000271 err = 0;
272 goto out_free_item;
David Chinner2a82b8b2007-07-11 11:09:12 +1000273 }
274
David Chinner2a82b8b2007-07-11 11:09:12 +1000275 return 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000276
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000277out_free_item:
Christoph Hellwig1919add2014-04-23 07:11:51 +1000278 kmem_free(item);
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000279out_put_ag:
280 xfs_filestream_put_ag(mp, *agp);
David Chinner2a82b8b2007-07-11 11:09:12 +1000281 return err;
282}
283
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000284static struct xfs_inode *
285xfs_filestream_get_parent(
286 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000287{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000288 struct inode *inode = VFS_I(ip), *dir = NULL;
289 struct dentry *dentry, *parent;
290
291 dentry = d_find_alias(inode);
292 if (!dentry)
293 goto out;
294
295 parent = dget_parent(dentry);
296 if (!parent)
297 goto out_dput;
298
David Howells2b0143b2015-03-17 22:25:59 +0000299 dir = igrab(d_inode(parent));
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000300 dput(parent);
301
302out_dput:
303 dput(dentry);
304out:
305 return dir ? XFS_I(dir) : NULL;
David Chinner2a82b8b2007-07-11 11:09:12 +1000306}
307
308/*
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000309 * 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.
David Chinner2a82b8b2007-07-11 11:09:12 +1000313 */
314xfs_agnumber_t
315xfs_filestream_lookup_ag(
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000316 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000317{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000318 struct xfs_mount *mp = ip->i_mount;
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000319 struct xfs_inode *pip = NULL;
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000320 xfs_agnumber_t startag, ag = NULLAGNUMBER;
Christoph Hellwig22328d72014-04-23 07:11:51 +1000321 struct xfs_mru_cache_elem *mru;
David Chinner2a82b8b2007-07-11 11:09:12 +1000322
Dave Chinnerc19b3b052016-02-09 16:54:58 +1100323 ASSERT(S_ISREG(VFS_I(ip)->i_mode));
David Chinner2a82b8b2007-07-11 11:09:12 +1000324
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000325 pip = xfs_filestream_get_parent(ip);
326 if (!pip)
Eric Sandeenb26384d2015-03-25 14:54:25 +1100327 return NULLAGNUMBER;
David Chinner2a82b8b2007-07-11 11:09:12 +1000328
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000329 mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
Christoph Hellwig22328d72014-04-23 07:11:51 +1000330 if (mru) {
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000331 ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
Christoph Hellwig22328d72014-04-23 07:11:51 +1000332 xfs_mru_cache_done(mp->m_filestream);
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000333
Christoph Hellwigb94acd42014-04-23 07:11:52 +1000334 trace_xfs_filestream_lookup(ip, ag);
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000335 goto out;
David Chinner2a82b8b2007-07-11 11:09:12 +1000336 }
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) {
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000343 xfs_agnumber_t rotorstep = xfs_rotorstep;
David Chinner2a82b8b2007-07-11 11:09:12 +1000344 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
Christoph Hellwig3b8d9072014-04-23 07:11:52 +1000350 if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
351 ag = NULLAGNUMBER;
352out:
353 IRELE(pip);
354 return ag;
David Chinner2a82b8b2007-07-11 11:09:12 +1000355}
356
357/*
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000358 * 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.
David Chinner2a82b8b2007-07-11 11:09:12 +1000362 */
363int
364xfs_filestream_new_ag(
Dave Chinner68988112013-08-12 20:49:42 +1000365 struct xfs_bmalloca *ap,
366 xfs_agnumber_t *agp)
David Chinner2a82b8b2007-07-11 11:09:12 +1000367{
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000368 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;
David Chinner2a82b8b2007-07-11 11:09:12 +1000374
David Chinner2a82b8b2007-07-11 11:09:12 +1000375 *agp = NULLAGNUMBER;
376
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000377 pip = xfs_filestream_get_parent(ip);
378 if (!pip)
379 goto exit;
380
381 mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
Christoph Hellwig22328d72014-04-23 07:11:51 +1000382 if (mru) {
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000383 struct xfs_fstrm_item *item =
384 container_of(mru, struct xfs_fstrm_item, mru);
385 startag = (item->ag + 1) % mp->m_sb.sb_agcount;
David Chinner2a82b8b2007-07-11 11:09:12 +1000386 }
387
David Chinner2a82b8b2007-07-11 11:09:12 +1000388 flags = (ap->userdata ? XFS_PICK_USERDATA : 0) |
Darrick J. Wong2c3234d2016-08-03 11:19:29 +1000389 (ap->dfops->dop_low ? XFS_PICK_LOWSPACE : 0);
David Chinner2a82b8b2007-07-11 11:09:12 +1000390
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000391 err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
David Chinner2a82b8b2007-07-11 11:09:12 +1000392
393 /*
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000394 * Only free the item here so we skip over the old AG earlier.
David Chinner2a82b8b2007-07-11 11:09:12 +1000395 */
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000396 if (mru)
397 xfs_fstrm_free_func(mru);
David Chinner2a82b8b2007-07-11 11:09:12 +1000398
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000399 IRELE(pip);
David Chinner2a82b8b2007-07-11 11:09:12 +1000400exit:
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000401 if (*agp == NULLAGNUMBER)
David Chinner2a82b8b2007-07-11 11:09:12 +1000402 *agp = 0;
David Chinner2a82b8b2007-07-11 11:09:12 +1000403 return err;
404}
405
David Chinner2a82b8b2007-07-11 11:09:12 +1000406void
407xfs_filestream_deassociate(
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000408 struct xfs_inode *ip)
David Chinner2a82b8b2007-07-11 11:09:12 +1000409{
Christoph Hellwig22328d72014-04-23 07:11:51 +1000410 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
David Chinner2a82b8b2007-07-11 11:09:12 +1000411}
Christoph Hellwig2cd2ef62014-04-23 07:11:51 +1000412
413int
414xfs_filestream_mount(
415 xfs_mount_t *mp)
416{
417 /*
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.
423 */
424 return xfs_mru_cache_create(&mp->m_filestream, xfs_fstrm_centisecs * 10,
425 10, xfs_fstrm_free_func);
426}
427
428void
429xfs_filestream_unmount(
430 xfs_mount_t *mp)
431{
432 xfs_mru_cache_destroy(mp->m_filestream);
433}