1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2006-2007 Silicon Graphics, Inc.
4 * Copyright (c) 2014 Christoph Hellwig.
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"
15 #include "xfs_bmap_util.h"
16 #include "xfs_alloc.h"
17 #include "xfs_mru_cache.h"
18 #include "xfs_trace.h"
20 #include "xfs_ag_resv.h"
21 #include "xfs_trans.h"
22 #include "xfs_filestream.h"
24 struct xfs_fstrm_item {
25 struct xfs_mru_cache_elem mru;
26 struct xfs_perag *pag; /* AG in use for this directory */
29 enum xfs_fstrm_alloc {
30 XFS_PICK_USERDATA = 1,
31 XFS_PICK_LOWSPACE = 2,
37 struct xfs_mru_cache_elem *mru)
39 struct xfs_fstrm_item *item =
40 container_of(mru, struct xfs_fstrm_item, mru);
41 struct xfs_perag *pag = item->pag;
43 trace_xfs_filestream_free(pag, mru->key);
44 atomic_dec(&pag->pagf_fstrms);
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.
56 xfs_filestream_pick_ag(
57 struct xfs_alloc_arg *args,
59 xfs_agnumber_t start_agno,
61 xfs_extlen_t *longest)
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 free = 0, minfree, maxfree = 0;
69 bool first_pass = true;
72 /* 2% of an AG's blocks must be free for it to be chosen. */
73 minfree = mp->m_sb.sb_agblocks / 50;
76 for_each_perag_wrap(mp, start_agno, agno, pag) {
77 trace_xfs_filestream_scan(pag, pino);
79 err = xfs_bmap_longest_free_extent(pag, NULL, longest);
84 /* Couldn't lock the AGF, skip this AG. */
89 /* Keep track of the AG with the most free blocks. */
90 if (pag->pagf_freeblks > maxfree) {
91 maxfree = pag->pagf_freeblks;
93 xfs_perag_rele(max_pag);
94 atomic_inc(&pag->pag_active_ref);
99 * The AG reference count does two things: it enforces mutual
100 * exclusion when examining the suitability of an AG in this
101 * loop, and it guards against two filestreams being established
102 * in the same AG as each other.
104 if (atomic_inc_return(&pag->pagf_fstrms) <= 1) {
105 if (((minlen && *longest >= minlen) ||
106 (!minlen && pag->pagf_freeblks >= minfree)) &&
107 (!xfs_perag_prefers_metadata(pag) ||
108 !(flags & XFS_PICK_USERDATA) ||
109 (flags & XFS_PICK_LOWSPACE))) {
110 /* Break out, retaining the reference on the AG. */
111 free = pag->pagf_freeblks;
116 /* Drop the reference on this AG, it's not usable. */
117 atomic_dec(&pag->pagf_fstrms);
123 xfs_perag_rele(max_pag);
129 * Allow a second pass to give xfs_bmap_longest_free_extent()
130 * another attempt at locking AGFs that it might have skipped
131 * over before we fail.
139 * We must be low on data space, so run a final lowspace
140 * optimised selection pass if we haven't already.
142 if (!(flags & XFS_PICK_LOWSPACE)) {
143 flags |= XFS_PICK_LOWSPACE;
148 * No unassociated AGs are available, so select the AG with the
149 * most free space, regardless of whether it's already in use by
150 * another filestream. It none suit, just use whatever AG we can
154 for_each_perag_wrap(args->mp, 0, start_agno, args->pag)
156 atomic_inc(&args->pag->pagf_fstrms);
161 atomic_inc(&pag->pagf_fstrms);
163 } else if (max_pag) {
164 xfs_perag_rele(max_pag);
167 trace_xfs_filestream_pick(pag, pino, free);
173 static struct xfs_inode *
174 xfs_filestream_get_parent(
175 struct xfs_inode *ip)
177 struct inode *inode = VFS_I(ip), *dir = NULL;
178 struct dentry *dentry, *parent;
180 dentry = d_find_alias(inode);
184 parent = dget_parent(dentry);
188 dir = igrab(d_inode(parent));
194 return dir ? XFS_I(dir) : NULL;
198 * Lookup the mru cache for an existing association. If one exists and we can
199 * use it, return with an active perag reference indicating that the allocation
200 * will proceed with that association.
202 * If we have no association, or we cannot use the current one and have to
203 * destroy it, return with longest = 0 to tell the caller to create a new
207 xfs_filestream_lookup_association(
208 struct xfs_bmalloca *ap,
209 struct xfs_alloc_arg *args,
211 xfs_extlen_t *longest)
213 struct xfs_mount *mp = args->mp;
214 struct xfs_perag *pag;
215 struct xfs_mru_cache_elem *mru;
219 mru = xfs_mru_cache_lookup(mp->m_filestream, pino);
223 * Grab the pag and take an extra active reference for the caller whilst
224 * the mru item cannot go away. This means we'll pin the perag with
225 * the reference we get here even if the filestreams association is torn
226 * down immediately after we mark the lookup as done.
228 pag = container_of(mru, struct xfs_fstrm_item, mru)->pag;
229 atomic_inc(&pag->pag_active_ref);
230 xfs_mru_cache_done(mp->m_filestream);
232 trace_xfs_filestream_lookup(pag, ap->ip->i_ino);
234 ap->blkno = XFS_AGB_TO_FSB(args->mp, pag->pag_agno, 0);
235 xfs_bmap_adjacent(ap);
238 * If there is very little free space before we start a filestreams
239 * allocation, we're almost guaranteed to fail to find a large enough
240 * free space available so just use the cached AG.
242 if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
247 error = xfs_bmap_longest_free_extent(pag, args->tp, longest);
248 if (error == -EAGAIN)
250 if (error || *longest < args->maxlen) {
251 /* We aren't going to use this perag */
263 xfs_filestream_create_association(
264 struct xfs_bmalloca *ap,
265 struct xfs_alloc_arg *args,
267 xfs_extlen_t *longest)
269 struct xfs_mount *mp = args->mp;
270 struct xfs_mru_cache_elem *mru;
271 struct xfs_fstrm_item *item;
272 xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, pino);
276 /* Changing parent AG association now, so remove the existing one. */
277 mru = xfs_mru_cache_remove(mp->m_filestream, pino);
279 struct xfs_fstrm_item *item =
280 container_of(mru, struct xfs_fstrm_item, mru);
282 agno = (item->pag->pag_agno + 1) % mp->m_sb.sb_agcount;
283 xfs_fstrm_free_func(mp, mru);
284 } else if (xfs_is_inode32(mp)) {
285 xfs_agnumber_t rotorstep = xfs_rotorstep;
287 agno = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
288 mp->m_agfrotor = (mp->m_agfrotor + 1) %
289 (mp->m_sb.sb_agcount * rotorstep);
292 ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
293 xfs_bmap_adjacent(ap);
295 if (ap->datatype & XFS_ALLOC_USERDATA)
296 flags |= XFS_PICK_USERDATA;
297 if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
298 flags |= XFS_PICK_LOWSPACE;
300 *longest = ap->length;
301 error = xfs_filestream_pick_ag(args, pino, agno, flags, longest);
306 * We are going to use this perag now, so create an assoication for it.
307 * xfs_filestream_pick_ag() has already bumped the perag fstrms counter
308 * for us, so all we need to do here is take another active reference to
309 * the perag for the cached association.
311 * If we fail to store the association, we need to drop the fstrms
312 * counter as well as drop the perag reference we take here for the
313 * item. We do not need to return an error for this failure - as long as
314 * we return a referenced AG, the allocation can still go ahead just
317 item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
321 atomic_inc(&args->pag->pag_active_ref);
322 item->pag = args->pag;
323 error = xfs_mru_cache_insert(mp->m_filestream, pino, &item->mru);
329 xfs_perag_rele(item->pag);
332 atomic_dec(&args->pag->pagf_fstrms);
337 * Search for an allocation group with a single extent large enough for
338 * the request. First we look for an existing association and use that if it
339 * is found. Otherwise, we create a new association by selecting an AG that fits
340 * the allocation criteria.
342 * We return with a referenced perag in args->pag to indicate which AG we are
343 * allocating into or an error with no references held.
346 xfs_filestream_select_ag(
347 struct xfs_bmalloca *ap,
348 struct xfs_alloc_arg *args,
349 xfs_extlen_t *longest)
351 struct xfs_mount *mp = args->mp;
352 struct xfs_inode *pip;
357 args->total = ap->total;
358 pip = xfs_filestream_get_parent(ap->ip);
361 error = xfs_filestream_lookup_association(ap, args, ino,
366 if (*longest >= args->maxlen)
368 if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
372 error = xfs_filestream_create_association(ap, args, ino, longest);
377 ap->blkno = XFS_AGB_TO_FSB(mp, args->pag->pag_agno, 0);
382 xfs_filestream_deassociate(
383 struct xfs_inode *ip)
385 xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
389 xfs_filestream_mount(
393 * The filestream timer tunable is currently fixed within the range of
394 * one second to four minutes, with five seconds being the default. The
395 * group count is somewhat arbitrary, but it'd be nice to adhere to the
396 * timer tunable to within about 10 percent. This requires at least 10
399 return xfs_mru_cache_create(&mp->m_filestream, mp,
400 xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
404 xfs_filestream_unmount(
407 xfs_mru_cache_destroy(mp->m_filestream);