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v6.9.4
  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		free = 0, minfree, maxfree = 0;
 68	xfs_agnumber_t		agno;
 69	bool			first_pass = true;
 70	int			err;
 71
 72	/* 2% of an AG's blocks must be free for it to be chosen. */
 73	minfree = mp->m_sb.sb_agblocks / 50;
 74
 75restart:
 76	for_each_perag_wrap(mp, start_agno, agno, pag) {
 77		trace_xfs_filestream_scan(pag, pino);
 78		*longest = 0;
 79		err = xfs_bmap_longest_free_extent(pag, NULL, longest);
 80		if (err) {
 81			if (err != -EAGAIN)
 82				break;
 83			/* Couldn't lock the AGF, skip this AG. */
 84			err = 0;
 85			continue;
 
 
 
 
 
 
 
 
 
 86		}
 87
 88		/* Keep track of the AG with the most free blocks. */
 89		if (pag->pagf_freeblks > maxfree) {
 90			maxfree = pag->pagf_freeblks;
 91			if (max_pag)
 92				xfs_perag_rele(max_pag);
 93			atomic_inc(&pag->pag_active_ref);
 94			max_pag = pag;
 95		}
 96
 97		/*
 98		 * The AG reference count does two things: it enforces mutual
 99		 * exclusion when examining the suitability of an AG in this
100		 * loop, and it guards against two filestreams being established
101		 * in the same AG as each other.
102		 */
103		if (atomic_inc_return(&pag->pagf_fstrms) <= 1) {
104			if (((minlen && *longest >= minlen) ||
105			     (!minlen && pag->pagf_freeblks >= minfree)) &&
106			    (!xfs_perag_prefers_metadata(pag) ||
107			     !(flags & XFS_PICK_USERDATA) ||
108			     (flags & XFS_PICK_LOWSPACE))) {
109				/* Break out, retaining the reference on the AG. */
110				free = pag->pagf_freeblks;
111				break;
112			}
 
 
 
 
 
 
 
 
113		}
114
115		/* Drop the reference on this AG, it's not usable. */
116		atomic_dec(&pag->pagf_fstrms);
117	}
 
 
 
 
118
119	if (err) {
120		xfs_perag_rele(pag);
121		if (max_pag)
122			xfs_perag_rele(max_pag);
123		return err;
124	}
125
126	if (!pag) {
127		/*
128		 * Allow a second pass to give xfs_bmap_longest_free_extent()
129		 * another attempt at locking AGFs that it might have skipped
130		 * over before we fail.
131		 */
132		if (first_pass) {
133			first_pass = false;
134			goto restart;
135		}
136
137		/*
138		 * We must be low on data space, so run a final lowspace
139		 * optimised selection pass if we haven't already.
140		 */
141		if (!(flags & XFS_PICK_LOWSPACE)) {
142			flags |= XFS_PICK_LOWSPACE;
143			goto restart;
144		}
145
146		/*
147		 * No unassociated AGs are available, so select the AG with the
148		 * most free space, regardless of whether it's already in use by
149		 * another filestream. It none suit, just use whatever AG we can
150		 * grab.
151		 */
152		if (!max_pag) {
153			for_each_perag_wrap(args->mp, 0, start_agno, args->pag)
154				break;
155			atomic_inc(&args->pag->pagf_fstrms);
156			*longest = 0;
157		} else {
158			pag = max_pag;
159			free = maxfree;
160			atomic_inc(&pag->pagf_fstrms);
 
161		}
162	} else if (max_pag) {
163		xfs_perag_rele(max_pag);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
164	}
165
166	trace_xfs_filestream_pick(pag, pino, free);
167	args->pag = pag;
168	return 0;
169
 
 
 
 
 
170}
171
172static struct xfs_inode *
173xfs_filestream_get_parent(
174	struct xfs_inode	*ip)
175{
176	struct inode		*inode = VFS_I(ip), *dir = NULL;
177	struct dentry		*dentry, *parent;
178
179	dentry = d_find_alias(inode);
180	if (!dentry)
181		goto out;
182
183	parent = dget_parent(dentry);
184	if (!parent)
185		goto out_dput;
186
187	dir = igrab(d_inode(parent));
188	dput(parent);
189
190out_dput:
191	dput(dentry);
192out:
193	return dir ? XFS_I(dir) : NULL;
194}
195
196/*
197 * Lookup the mru cache for an existing association. If one exists and we can
198 * use it, return with an active perag reference indicating that the allocation
199 * will proceed with that association.
200 *
201 * If we have no association, or we cannot use the current one and have to
202 * destroy it, return with longest = 0 to tell the caller to create a new
203 * association.
204 */
205static int
206xfs_filestream_lookup_association(
207	struct xfs_bmalloca	*ap,
208	struct xfs_alloc_arg	*args,
209	xfs_ino_t		pino,
210	xfs_extlen_t		*longest)
211{
212	struct xfs_mount	*mp = args->mp;
213	struct xfs_perag	*pag;
 
214	struct xfs_mru_cache_elem *mru;
215	int			error = 0;
216
217	*longest = 0;
218	mru = xfs_mru_cache_lookup(mp->m_filestream, pino);
219	if (!mru)
220		return 0;
221	/*
222	 * Grab the pag and take an extra active reference for the caller whilst
223	 * the mru item cannot go away. This means we'll pin the perag with
224	 * the reference we get here even if the filestreams association is torn
225	 * down immediately after we mark the lookup as done.
226	 */
227	pag = container_of(mru, struct xfs_fstrm_item, mru)->pag;
228	atomic_inc(&pag->pag_active_ref);
229	xfs_mru_cache_done(mp->m_filestream);
230
231	trace_xfs_filestream_lookup(pag, ap->ip->i_ino);
 
 
232
233	ap->blkno = XFS_AGB_TO_FSB(args->mp, pag->pag_agno, 0);
234	xfs_bmap_adjacent(ap);
 
 
235
236	/*
237	 * If there is very little free space before we start a filestreams
238	 * allocation, we're almost guaranteed to fail to find a large enough
239	 * free space available so just use the cached AG.
240	 */
241	if (ap->tp->t_flags & XFS_TRANS_LOWMODE) {
242		*longest = 1;
243		goto out_done;
244	}
245
246	error = xfs_bmap_longest_free_extent(pag, args->tp, longest);
247	if (error == -EAGAIN)
248		error = 0;
249	if (error || *longest < args->maxlen) {
250		/* We aren't going to use this perag */
251		*longest = 0;
252		xfs_perag_rele(pag);
253		return error;
254	}
 
 
255
256out_done:
257	args->pag = pag;
258	return 0;
 
 
259}
260
261static int
262xfs_filestream_create_association(
 
 
 
 
 
 
263	struct xfs_bmalloca	*ap,
264	struct xfs_alloc_arg	*args,
265	xfs_ino_t		pino,
266	xfs_extlen_t		*longest)
267{
268	struct xfs_mount	*mp = args->mp;
269	struct xfs_mru_cache_elem *mru;
270	struct xfs_fstrm_item	*item;
271	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, pino);
272	int			flags = 0;
273	int			error;
 
 
 
274
275	/* Changing parent AG association now, so remove the existing one. */
276	mru = xfs_mru_cache_remove(mp->m_filestream, pino);
 
 
 
277	if (mru) {
278		struct xfs_fstrm_item *item =
279			container_of(mru, struct xfs_fstrm_item, mru);
280
281		agno = (item->pag->pag_agno + 1) % mp->m_sb.sb_agcount;
282		xfs_fstrm_free_func(mp, mru);
283	} else if (xfs_is_inode32(mp)) {
284		xfs_agnumber_t	 rotorstep = xfs_rotorstep;
285
286		agno = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
287		mp->m_agfrotor = (mp->m_agfrotor + 1) %
288				 (mp->m_sb.sb_agcount * rotorstep);
289	}
290
291	ap->blkno = XFS_AGB_TO_FSB(args->mp, agno, 0);
292	xfs_bmap_adjacent(ap);
293
294	if (ap->datatype & XFS_ALLOC_USERDATA)
295		flags |= XFS_PICK_USERDATA;
296	if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
297		flags |= XFS_PICK_LOWSPACE;
298
299	*longest = ap->length;
300	error = xfs_filestream_pick_ag(args, pino, agno, flags, longest);
301	if (error)
302		return error;
303
304	/*
305	 * We are going to use this perag now, so create an assoication for it.
306	 * xfs_filestream_pick_ag() has already bumped the perag fstrms counter
307	 * for us, so all we need to do here is take another active reference to
308	 * the perag for the cached association.
309	 *
310	 * If we fail to store the association, we need to drop the fstrms
311	 * counter as well as drop the perag reference we take here for the
312	 * item. We do not need to return an error for this failure - as long as
313	 * we return a referenced AG, the allocation can still go ahead just
314	 * fine.
315	 */
316	item = kmalloc(sizeof(*item), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
317	if (!item)
318		goto out_put_fstrms;
319
320	atomic_inc(&args->pag->pag_active_ref);
321	item->pag = args->pag;
322	error = xfs_mru_cache_insert(mp->m_filestream, pino, &item->mru);
323	if (error)
324		goto out_free_item;
325	return 0;
326
327out_free_item:
328	xfs_perag_rele(item->pag);
329	kfree(item);
330out_put_fstrms:
331	atomic_dec(&args->pag->pagf_fstrms);
332	return 0;
333}
334
335/*
336 * Search for an allocation group with a single extent large enough for
337 * the request. First we look for an existing association and use that if it
338 * is found. Otherwise, we create a new association by selecting an AG that fits
339 * the allocation criteria.
340 *
341 * We return with a referenced perag in args->pag to indicate which AG we are
342 * allocating into or an error with no references held.
343 */
344int
345xfs_filestream_select_ag(
346	struct xfs_bmalloca	*ap,
347	struct xfs_alloc_arg	*args,
348	xfs_extlen_t		*longest)
349{
350	struct xfs_mount	*mp = args->mp;
351	struct xfs_inode	*pip;
352	xfs_ino_t		ino = 0;
353	int			error = 0;
354
355	*longest = 0;
356	args->total = ap->total;
357	pip = xfs_filestream_get_parent(ap->ip);
358	if (pip) {
359		ino = pip->i_ino;
360		error = xfs_filestream_lookup_association(ap, args, ino,
361				longest);
362		xfs_irele(pip);
363		if (error)
364			return error;
365		if (*longest >= args->maxlen)
366			goto out_select;
367		if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
368			goto out_select;
369	}
370
371	error = xfs_filestream_create_association(ap, args, ino, longest);
372	if (error)
373		return error;
374
375out_select:
376	ap->blkno = XFS_AGB_TO_FSB(mp, args->pag->pag_agno, 0);
377	return 0;
 
 
378}
379
380void
381xfs_filestream_deassociate(
382	struct xfs_inode	*ip)
383{
384	xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
385}
386
387int
388xfs_filestream_mount(
389	xfs_mount_t	*mp)
390{
391	/*
392	 * The filestream timer tunable is currently fixed within the range of
393	 * one second to four minutes, with five seconds being the default.  The
394	 * group count is somewhat arbitrary, but it'd be nice to adhere to the
395	 * timer tunable to within about 10 percent.  This requires at least 10
396	 * groups.
397	 */
398	return xfs_mru_cache_create(&mp->m_filestream, mp,
399			xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
400}
401
402void
403xfs_filestream_unmount(
404	xfs_mount_t	*mp)
405{
406	xfs_mru_cache_destroy(mp->m_filestream);
407}
v5.14.15
  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_alloc.h"
 16#include "xfs_mru_cache.h"
 17#include "xfs_trace.h"
 18#include "xfs_ag.h"
 19#include "xfs_ag_resv.h"
 20#include "xfs_trans.h"
 21#include "xfs_filestream.h"
 22
 23struct xfs_fstrm_item {
 24	struct xfs_mru_cache_elem	mru;
 25	xfs_agnumber_t			ag; /* AG in use for this directory */
 26};
 27
 28enum xfs_fstrm_alloc {
 29	XFS_PICK_USERDATA = 1,
 30	XFS_PICK_LOWSPACE = 2,
 31};
 32
 33/*
 34 * Allocation group filestream associations are tracked with per-ag atomic
 35 * counters.  These counters allow xfs_filestream_pick_ag() to tell whether a
 36 * particular AG already has active filestreams associated with it.
 37 */
 38int
 39xfs_filestream_peek_ag(
 40	xfs_mount_t	*mp,
 41	xfs_agnumber_t	agno)
 42{
 43	struct xfs_perag *pag;
 44	int		ret;
 45
 46	pag = xfs_perag_get(mp, agno);
 47	ret = atomic_read(&pag->pagf_fstrms);
 48	xfs_perag_put(pag);
 49	return ret;
 50}
 51
 52static int
 53xfs_filestream_get_ag(
 54	xfs_mount_t	*mp,
 55	xfs_agnumber_t	agno)
 56{
 57	struct xfs_perag *pag;
 58	int		ret;
 59
 60	pag = xfs_perag_get(mp, agno);
 61	ret = atomic_inc_return(&pag->pagf_fstrms);
 62	xfs_perag_put(pag);
 63	return ret;
 64}
 65
 66static void
 67xfs_filestream_put_ag(
 68	xfs_mount_t	*mp,
 69	xfs_agnumber_t	agno)
 70{
 71	struct xfs_perag *pag;
 72
 73	pag = xfs_perag_get(mp, agno);
 74	atomic_dec(&pag->pagf_fstrms);
 75	xfs_perag_put(pag);
 76}
 77
 78static void
 79xfs_fstrm_free_func(
 80	void			*data,
 81	struct xfs_mru_cache_elem *mru)
 82{
 83	struct xfs_mount	*mp = data;
 84	struct xfs_fstrm_item	*item =
 85		container_of(mru, struct xfs_fstrm_item, mru);
 
 86
 87	xfs_filestream_put_ag(mp, item->ag);
 88	trace_xfs_filestream_free(mp, mru->key, item->ag);
 
 89
 90	kmem_free(item);
 91}
 92
 93/*
 94 * Scan the AGs starting at startag looking for an AG that isn't in use and has
 95 * at least minlen blocks free.
 
 96 */
 97static int
 98xfs_filestream_pick_ag(
 99	struct xfs_inode	*ip,
100	xfs_agnumber_t		startag,
101	xfs_agnumber_t		*agp,
102	int			flags,
103	xfs_extlen_t		minlen)
104{
105	struct xfs_mount	*mp = ip->i_mount;
106	struct xfs_fstrm_item	*item;
107	struct xfs_perag	*pag;
108	xfs_extlen_t		longest, free = 0, minfree, maxfree = 0;
109	xfs_agnumber_t		ag, max_ag = NULLAGNUMBER;
110	int			err, trylock, nscan;
111
112	ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
 
113
114	/* 2% of an AG's blocks must be free for it to be chosen. */
115	minfree = mp->m_sb.sb_agblocks / 50;
116
117	ag = startag;
118	*agp = NULLAGNUMBER;
119
120	/* For the first pass, don't sleep trying to init the per-AG. */
121	trylock = XFS_ALLOC_FLAG_TRYLOCK;
122
123	for (nscan = 0; 1; nscan++) {
124		trace_xfs_filestream_scan(mp, ip->i_ino, ag);
125
126		pag = xfs_perag_get(mp, ag);
127
128		if (!pag->pagf_init) {
129			err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
130			if (err) {
131				xfs_perag_put(pag);
132				if (err != -EAGAIN)
133					return err;
134				/* Couldn't lock the AGF, skip this AG. */
135				continue;
136			}
137		}
138
139		/* Keep track of the AG with the most free blocks. */
140		if (pag->pagf_freeblks > maxfree) {
141			maxfree = pag->pagf_freeblks;
142			max_ag = ag;
 
 
 
143		}
144
145		/*
146		 * The AG reference count does two things: it enforces mutual
147		 * exclusion when examining the suitability of an AG in this
148		 * loop, and it guards against two filestreams being established
149		 * in the same AG as each other.
150		 */
151		if (xfs_filestream_get_ag(mp, ag) > 1) {
152			xfs_filestream_put_ag(mp, ag);
153			goto next_ag;
154		}
155
156		longest = xfs_alloc_longest_free_extent(pag,
157				xfs_alloc_min_freelist(mp, pag),
158				xfs_ag_resv_needed(pag, XFS_AG_RESV_NONE));
159		if (((minlen && longest >= minlen) ||
160		     (!minlen && pag->pagf_freeblks >= minfree)) &&
161		    (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||
162		     (flags & XFS_PICK_LOWSPACE))) {
163
164			/* Break out, retaining the reference on the AG. */
165			free = pag->pagf_freeblks;
166			xfs_perag_put(pag);
167			*agp = ag;
168			break;
169		}
170
171		/* Drop the reference on this AG, it's not usable. */
172		xfs_filestream_put_ag(mp, ag);
173next_ag:
174		xfs_perag_put(pag);
175		/* Move to the next AG, wrapping to AG 0 if necessary. */
176		if (++ag >= mp->m_sb.sb_agcount)
177			ag = 0;
178
179		/* If a full pass of the AGs hasn't been done yet, continue. */
180		if (ag != startag)
181			continue;
 
 
 
182
183		/* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */
184		if (trylock != 0) {
185			trylock = 0;
186			continue;
 
 
 
 
 
187		}
188
189		/* Finally, if lowspace wasn't set, set it for the 3rd pass. */
 
 
 
190		if (!(flags & XFS_PICK_LOWSPACE)) {
191			flags |= XFS_PICK_LOWSPACE;
192			continue;
193		}
194
195		/*
196		 * Take the AG with the most free space, regardless of whether
197		 * it's already in use by another filestream.
 
 
198		 */
199		if (max_ag != NULLAGNUMBER) {
200			xfs_filestream_get_ag(mp, max_ag);
 
 
 
 
 
201			free = maxfree;
202			*agp = max_ag;
203			break;
204		}
205
206		/* take AG 0 if none matched */
207		trace_xfs_filestream_pick(ip, *agp, free, nscan);
208		*agp = 0;
209		return 0;
210	}
211
212	trace_xfs_filestream_pick(ip, *agp, free, nscan);
213
214	if (*agp == NULLAGNUMBER)
215		return 0;
216
217	err = -ENOMEM;
218	item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
219	if (!item)
220		goto out_put_ag;
221
222	item->ag = *agp;
223
224	err = xfs_mru_cache_insert(mp->m_filestream, ip->i_ino, &item->mru);
225	if (err) {
226		if (err == -EEXIST)
227			err = 0;
228		goto out_free_item;
229	}
230
 
 
231	return 0;
232
233out_free_item:
234	kmem_free(item);
235out_put_ag:
236	xfs_filestream_put_ag(mp, *agp);
237	return err;
238}
239
240static struct xfs_inode *
241xfs_filestream_get_parent(
242	struct xfs_inode	*ip)
243{
244	struct inode		*inode = VFS_I(ip), *dir = NULL;
245	struct dentry		*dentry, *parent;
246
247	dentry = d_find_alias(inode);
248	if (!dentry)
249		goto out;
250
251	parent = dget_parent(dentry);
252	if (!parent)
253		goto out_dput;
254
255	dir = igrab(d_inode(parent));
256	dput(parent);
257
258out_dput:
259	dput(dentry);
260out:
261	return dir ? XFS_I(dir) : NULL;
262}
263
264/*
265 * Find the right allocation group for a file, either by finding an
266 * existing file stream or creating a new one.
 
267 *
268 * Returns NULLAGNUMBER in case of an error.
 
 
269 */
270xfs_agnumber_t
271xfs_filestream_lookup_ag(
272	struct xfs_inode	*ip)
 
 
 
273{
274	struct xfs_mount	*mp = ip->i_mount;
275	struct xfs_inode	*pip = NULL;
276	xfs_agnumber_t		startag, ag = NULLAGNUMBER;
277	struct xfs_mru_cache_elem *mru;
 
278
279	ASSERT(S_ISREG(VFS_I(ip)->i_mode));
 
 
 
 
 
 
 
 
 
 
 
 
280
281	pip = xfs_filestream_get_parent(ip);
282	if (!pip)
283		return NULLAGNUMBER;
284
285	mru = xfs_mru_cache_lookup(mp->m_filestream, pip->i_ino);
286	if (mru) {
287		ag = container_of(mru, struct xfs_fstrm_item, mru)->ag;
288		xfs_mru_cache_done(mp->m_filestream);
289
290		trace_xfs_filestream_lookup(mp, ip->i_ino, ag);
291		goto out;
 
 
 
 
 
 
292	}
293
294	/*
295	 * Set the starting AG using the rotor for inode32, otherwise
296	 * use the directory inode's AG.
297	 */
298	if (mp->m_flags & XFS_MOUNT_32BITINODES) {
299		xfs_agnumber_t	 rotorstep = xfs_rotorstep;
300		startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount;
301		mp->m_agfrotor = (mp->m_agfrotor + 1) %
302		                 (mp->m_sb.sb_agcount * rotorstep);
303	} else
304		startag = XFS_INO_TO_AGNO(mp, pip->i_ino);
305
306	if (xfs_filestream_pick_ag(pip, startag, &ag, 0, 0))
307		ag = NULLAGNUMBER;
308out:
309	xfs_irele(pip);
310	return ag;
311}
312
313/*
314 * Pick a new allocation group for the current file and its file stream.
315 *
316 * This is called when the allocator can't find a suitable extent in the
317 * current AG, and we have to move the stream into a new AG with more space.
318 */
319int
320xfs_filestream_new_ag(
321	struct xfs_bmalloca	*ap,
322	xfs_agnumber_t		*agp)
 
 
323{
324	struct xfs_inode	*ip = ap->ip, *pip;
325	struct xfs_mount	*mp = ip->i_mount;
326	xfs_extlen_t		minlen = ap->length;
327	xfs_agnumber_t		startag = 0;
328	int			flags = 0;
329	int			err = 0;
330	struct xfs_mru_cache_elem *mru;
331
332	*agp = NULLAGNUMBER;
333
334	pip = xfs_filestream_get_parent(ip);
335	if (!pip)
336		goto exit;
337
338	mru = xfs_mru_cache_remove(mp->m_filestream, pip->i_ino);
339	if (mru) {
340		struct xfs_fstrm_item *item =
341			container_of(mru, struct xfs_fstrm_item, mru);
342		startag = (item->ag + 1) % mp->m_sb.sb_agcount;
 
 
 
 
 
 
 
 
343	}
344
 
 
 
345	if (ap->datatype & XFS_ALLOC_USERDATA)
346		flags |= XFS_PICK_USERDATA;
347	if (ap->tp->t_flags & XFS_TRANS_LOWMODE)
348		flags |= XFS_PICK_LOWSPACE;
349
350	err = xfs_filestream_pick_ag(pip, startag, agp, flags, minlen);
 
 
 
351
352	/*
353	 * Only free the item here so we skip over the old AG earlier.
 
 
 
 
 
 
 
 
 
354	 */
355	if (mru)
356		xfs_fstrm_free_func(mp, mru);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
357
358	xfs_irele(pip);
359exit:
360	if (*agp == NULLAGNUMBER)
361		*agp = 0;
362	return err;
363}
364
365void
366xfs_filestream_deassociate(
367	struct xfs_inode	*ip)
368{
369	xfs_mru_cache_delete(ip->i_mount->m_filestream, ip->i_ino);
370}
371
372int
373xfs_filestream_mount(
374	xfs_mount_t	*mp)
375{
376	/*
377	 * The filestream timer tunable is currently fixed within the range of
378	 * one second to four minutes, with five seconds being the default.  The
379	 * group count is somewhat arbitrary, but it'd be nice to adhere to the
380	 * timer tunable to within about 10 percent.  This requires at least 10
381	 * groups.
382	 */
383	return xfs_mru_cache_create(&mp->m_filestream, mp,
384			xfs_fstrm_centisecs * 10, 10, xfs_fstrm_free_func);
385}
386
387void
388xfs_filestream_unmount(
389	xfs_mount_t	*mp)
390{
391	xfs_mru_cache_destroy(mp->m_filestream);
392}