diff options
| -rw-r--r-- | fs/xfs/Makefile | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_ag.h | 18 | ||||
| -rw-r--r-- | fs/xfs/xfs_alloc.c | 572 | ||||
| -rw-r--r-- | fs/xfs/xfs_alloc.h | 28 | ||||
| -rw-r--r-- | fs/xfs/xfs_alloc_btree.c | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_discard.c | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_extent_busy.c | 603 | ||||
| -rw-r--r-- | fs/xfs/xfs_extent_busy.h | 65 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_cil.c | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_trans.c | 1 |
10 files changed, 674 insertions, 617 deletions
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index 0a99779..ca9229f 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -33,6 +33,7 @@ xfs-y += xfs_aops.o \ xfs_discard.o \ xfs_error.o \ xfs_export.o \ + xfs_extent_busy.o \ xfs_file.o \ xfs_filestream.o \ xfs_fsops.o \ diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h index 4805f00..44d65c1 100644 --- a/fs/xfs/xfs_ag.h +++ b/fs/xfs/xfs_ag.h @@ -175,24 +175,6 @@ typedef struct xfs_agfl { } xfs_agfl_t; /* - * Busy block/extent entry. Indexed by a rbtree in perag to mark blocks that - * have been freed but whose transactions aren't committed to disk yet. - * - * Note that we use the transaction ID to record the transaction, not the - * transaction structure itself. See xfs_alloc_busy_insert() for details. - */ -struct xfs_busy_extent { - struct rb_node rb_node; /* ag by-bno indexed search tree */ - struct list_head list; /* transaction busy extent list */ - xfs_agnumber_t agno; - xfs_agblock_t bno; - xfs_extlen_t length; - unsigned int flags; -#define XFS_ALLOC_BUSY_DISCARDED 0x01 /* undergoing a discard op. */ -#define XFS_ALLOC_BUSY_SKIP_DISCARD 0x02 /* do not discard */ -}; - -/* * Per-ag incore structure, copies of information in agf and agi, * to improve the performance of allocation group selection. */ diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c index 95ee705..ae6df25 100644 --- a/fs/xfs/xfs_alloc.c +++ b/fs/xfs/xfs_alloc.c @@ -31,6 +31,7 @@ #include "xfs_inode.h" #include "xfs_btree.h" #include "xfs_alloc.h" +#include "xfs_extent_busy.h" #include "xfs_error.h" #include "xfs_trace.h" @@ -2500,574 +2501,3 @@ error0: xfs_perag_put(args.pag); return error; } - -void -xfs_alloc_busy_insert( - struct xfs_trans *tp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len, - unsigned int flags) -{ - struct xfs_busy_extent *new; - struct xfs_busy_extent *busyp; - struct xfs_perag *pag; - struct rb_node **rbp; - struct rb_node *parent = NULL; - - new = kmem_zalloc(sizeof(struct xfs_busy_extent), KM_MAYFAIL); - if (!new) { - /* - * No Memory! Since it is now not possible to track the free - * block, make this a synchronous transaction to insure that - * the block is not reused before this transaction commits. - */ - trace_xfs_alloc_busy_enomem(tp->t_mountp, agno, bno, len); - xfs_trans_set_sync(tp); - return; - } - - new->agno = agno; - new->bno = bno; - new->length = len; - INIT_LIST_HEAD(&new->list); - new->flags = flags; - - /* trace before insert to be able to see failed inserts */ - trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len); - - pag = xfs_perag_get(tp->t_mountp, new->agno); - spin_lock(&pag->pagb_lock); - rbp = &pag->pagb_tree.rb_node; - while (*rbp) { - parent = *rbp; - busyp = rb_entry(parent, struct xfs_busy_extent, rb_node); - - if (new->bno < busyp->bno) { - rbp = &(*rbp)->rb_left; - ASSERT(new->bno + new->length <= busyp->bno); - } else if (new->bno > busyp->bno) { - rbp = &(*rbp)->rb_right; - ASSERT(bno >= busyp->bno + busyp->length); - } else { - ASSERT(0); - } - } - - rb_link_node(&new->rb_node, parent, rbp); - rb_insert_color(&new->rb_node, &pag->pagb_tree); - - list_add(&new->list, &tp->t_busy); - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); -} - -/* - * Search for a busy extent within the range of the extent we are about to - * allocate. You need to be holding the busy extent tree lock when calling - * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy - * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact - * match. This is done so that a non-zero return indicates an overlap that - * will require a synchronous transaction, but it can still be - * used to distinguish between a partial or exact match. - */ -int -xfs_alloc_busy_search( - struct xfs_mount *mp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len) -{ - struct xfs_perag *pag; - struct rb_node *rbp; - struct xfs_busy_extent *busyp; - int match = 0; - - pag = xfs_perag_get(mp, agno); - spin_lock(&pag->pagb_lock); - - rbp = pag->pagb_tree.rb_node; - - /* find closest start bno overlap */ - while (rbp) { - busyp = rb_entry(rbp, struct xfs_busy_extent, rb_node); - if (bno < busyp->bno) { - /* may overlap, but exact start block is lower */ - if (bno + len > busyp->bno) - match = -1; - rbp = rbp->rb_left; - } else if (bno > busyp->bno) { - /* may overlap, but exact start block is higher */ - if (bno < busyp->bno + busyp->length) - match = -1; - rbp = rbp->rb_right; - } else { - /* bno matches busyp, length determines exact match */ - match = (busyp->length == len) ? 1 : -1; - break; - } - } - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); - return match; -} - -/* - * The found free extent [fbno, fend] overlaps part or all of the given busy - * extent. If the overlap covers the beginning, the end, or all of the busy - * extent, the overlapping portion can be made unbusy and used for the - * allocation. We can't split a busy extent because we can't modify a - * transaction/CIL context busy list, but we can update an entries block - * number or length. - * - * Returns true if the extent can safely be reused, or false if the search - * needs to be restarted. - */ -STATIC bool -xfs_alloc_busy_update_extent( - struct xfs_mount *mp, - struct xfs_perag *pag, - struct xfs_busy_extent *busyp, - xfs_agblock_t fbno, - xfs_extlen_t flen, - bool userdata) -{ - xfs_agblock_t fend = fbno + flen; - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - /* - * This extent is currently being discarded. Give the thread - * performing the discard a chance to mark the extent unbusy - * and retry. - */ - if (busyp->flags & XFS_ALLOC_BUSY_DISCARDED) { - spin_unlock(&pag->pagb_lock); - delay(1); - spin_lock(&pag->pagb_lock); - return false; - } - - /* - * If there is a busy extent overlapping a user allocation, we have - * no choice but to force the log and retry the search. - * - * Fortunately this does not happen during normal operation, but - * only if the filesystem is very low on space and has to dip into - * the AGFL for normal allocations. - */ - if (userdata) - goto out_force_log; - - if (bbno < fbno && bend > fend) { - /* - * Case 1: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - */ - - /* - * We would have to split the busy extent to be able to track - * it correct, which we cannot do because we would have to - * modify the list of busy extents attached to the transaction - * or CIL context, which is immutable. - * - * Force out the log to clear the busy extent and retry the - * search. - */ - goto out_force_log; - } else if (bbno >= fbno && bend <= fend) { - /* - * Case 2: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------+ - * fbno fend - * - * Case 3: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Case 4: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Case 5: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------------------------+ - * fbno fend - * - */ - - /* - * The busy extent is fully covered by the extent we are - * allocating, and can simply be removed from the rbtree. - * However we cannot remove it from the immutable list - * tracking busy extents in the transaction or CIL context, - * so set the length to zero to mark it invalid. - * - * We also need to restart the busy extent search from the - * tree root, because erasing the node can rearrange the - * tree topology. - */ - rb_erase(&busyp->rb_node, &pag->pagb_tree); - busyp->length = 0; - return false; - } else if (fend < bend) { - /* - * Case 6: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - * - * Case 7: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +------------------+ - * fbno fend - * - */ - busyp->bno = fend; - } else if (bbno < fbno) { - /* - * Case 8: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 9: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +----------------------+ - * fbno fend - */ - busyp->length = fbno - busyp->bno; - } else { - ASSERT(0); - } - - trace_xfs_alloc_busy_reuse(mp, pag->pag_agno, fbno, flen); - return true; - -out_force_log: - spin_unlock(&pag->pagb_lock); - xfs_log_force(mp, XFS_LOG_SYNC); - trace_xfs_alloc_busy_force(mp, pag->pag_agno, fbno, flen); - spin_lock(&pag->pagb_lock); - return false; -} - - -/* - * For a given extent [fbno, flen], make sure we can reuse it safely. - */ -void -xfs_alloc_busy_reuse( - struct xfs_mount *mp, - xfs_agnumber_t agno, - xfs_agblock_t fbno, - xfs_extlen_t flen, - bool userdata) -{ - struct xfs_perag *pag; - struct rb_node *rbp; - - ASSERT(flen > 0); - - pag = xfs_perag_get(mp, agno); - spin_lock(&pag->pagb_lock); -restart: - rbp = pag->pagb_tree.rb_node; - while (rbp) { - struct xfs_busy_extent *busyp = - rb_entry(rbp, struct xfs_busy_extent, rb_node); - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - if (fbno + flen <= bbno) { - rbp = rbp->rb_left; - continue; - } else if (fbno >= bend) { - rbp = rbp->rb_right; - continue; - } - - if (!xfs_alloc_busy_update_extent(mp, pag, busyp, fbno, flen, - userdata)) - goto restart; - } - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); -} - -/* - * For a given extent [fbno, flen], search the busy extent list to find a - * subset of the extent that is not busy. If *rlen is smaller than - * args->minlen no suitable extent could be found, and the higher level - * code needs to force out the log and retry the allocation. - */ -STATIC void -xfs_alloc_busy_trim( - struct xfs_alloc_arg *args, - xfs_agblock_t bno, - xfs_extlen_t len, - xfs_agblock_t *rbno, - xfs_extlen_t *rlen) -{ - xfs_agblock_t fbno; - xfs_extlen_t flen; - struct rb_node *rbp; - - ASSERT(len > 0); - - spin_lock(&args->pag->pagb_lock); -restart: - fbno = bno; - flen = len; - rbp = args->pag->pagb_tree.rb_node; - while (rbp && flen >= args->minlen) { - struct xfs_busy_extent *busyp = - rb_entry(rbp, struct xfs_busy_extent, rb_node); - xfs_agblock_t fend = fbno + flen; - xfs_agblock_t bbno = busyp->bno; - xfs_agblock_t bend = bbno + busyp->length; - - if (fend <= bbno) { - rbp = rbp->rb_left; - continue; - } else if (fbno >= bend) { - rbp = rbp->rb_right; - continue; - } - - /* - * If this is a metadata allocation, try to reuse the busy - * extent instead of trimming the allocation. - */ - if (!args->userdata && - !(busyp->flags & XFS_ALLOC_BUSY_DISCARDED)) { - if (!xfs_alloc_busy_update_extent(args->mp, args->pag, - busyp, fbno, flen, - false)) - goto restart; - continue; - } - - if (bbno <= fbno) { - /* start overlap */ - - /* - * Case 1: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +---------+ - * fbno fend - * - * Case 2: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 3: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-------------+ - * fbno fend - * - * Case 4: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------+ - * fbno fend - * - * No unbusy region in extent, return failure. - */ - if (fend <= bend) - goto fail; - - /* - * Case 5: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +----------------------+ - * fbno fend - * - * Case 6: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Needs to be trimmed to: - * +-------+ - * fbno fend - */ - fbno = bend; - } else if (bend >= fend) { - /* end overlap */ - - /* - * Case 7: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +------------------+ - * fbno fend - * - * Case 8: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +--------------------------+ - * fbno fend - * - * Needs to be trimmed to: - * +-------+ - * fbno fend - */ - fend = bbno; - } else { - /* middle overlap */ - - /* - * Case 9: - * bbno bend - * +BBBBBBBBBBBBBBBBB+ - * +-----------------------------------+ - * fbno fend - * - * Can be trimmed to: - * +-------+ OR +-------+ - * fbno fend fbno fend - * - * Backward allocation leads to significant - * fragmentation of directories, which degrades - * directory performance, therefore we always want to - * choose the option that produces forward allocation - * patterns. - * Preferring the lower bno extent will make the next - * request use "fend" as the start of the next - * allocation; if the segment is no longer busy at - * that point, we'll get a contiguous allocation, but - * even if it is still busy, we will get a forward - * allocation. - * We try to avoid choosing the segment at "bend", - * because that can lead to the next allocation - * taking the segment at "fbno", which would be a - * backward allocation. We only use the segment at - * "fbno" if it is much larger than the current - * requested size, because in that case there's a - * good chance subsequent allocations will be - * contiguous. - */ - if (bbno - fbno >= args->maxlen) { - /* left candidate fits perfect */ - fend = bbno; - } else if (fend - bend >= args->maxlen * 4) { - /* right candidate has enough free space */ - fbno = bend; - } else if (bbno - fbno >= args->minlen) { - /* left candidate fits minimum requirement */ - fend = bbno; - } else { - goto fail; - } - } - - flen = fend - fbno; - } - spin_unlock(&args->pag->pagb_lock); - - if (fbno != bno || flen != len) { - trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, - fbno, flen); - } - *rbno = fbno; - *rlen = flen; - return; -fail: - /* - * Return a zero extent length as failure indications. All callers - * re-check if the trimmed extent satisfies the minlen requirement. - */ - spin_unlock(&args->pag->pagb_lock); - trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, fbno, 0); - *rbno = fbno; - *rlen = 0; -} - -static void -xfs_alloc_busy_clear_one( - struct xfs_mount *mp, - struct xfs_perag *pag, - struct xfs_busy_extent *busyp) -{ - if (busyp->length) { - trace_xfs_alloc_busy_clear(mp, busyp->agno, busyp->bno, - busyp->length); - rb_erase(&busyp->rb_node, &pag->pagb_tree); - } - - list_del_init(&busyp->list); - kmem_free(busyp); -} - -/* - * Remove all extents on the passed in list from the busy extents tree. - * If do_discard is set skip extents that need to be discarded, and mark - * these as undergoing a discard operation instead. - */ -void -xfs_alloc_busy_clear( - struct xfs_mount *mp, - struct list_head *list, - bool do_discard) -{ - struct xfs_busy_extent *busyp, *n; - struct xfs_perag *pag = NULL; - xfs_agnumber_t agno = NULLAGNUMBER; - - list_for_each_entry_safe(busyp, n, list, list) { - if (busyp->agno != agno) { - if (pag) { - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); - } - pag = xfs_perag_get(mp, busyp->agno); - spin_lock(&pag->pagb_lock); - agno = busyp->agno; - } - - if (do_discard && busyp->length && - !(busyp->flags & XFS_ALLOC_BUSY_SKIP_DISCARD)) - busyp->flags = XFS_ALLOC_BUSY_DISCARDED; - else - xfs_alloc_busy_clear_one(mp, pag, busyp); - } - - if (pag) { - spin_unlock(&pag->pagb_lock); - xfs_perag_put(pag); - } -} - -/* - * Callback for list_sort to sort busy extents by the AG they reside in. - */ -int -xfs_busy_extent_ag_cmp( - void *priv, - struct list_head *a, - struct list_head *b) -{ - return container_of(a, struct xfs_busy_extent, list)->agno - - container_of(b, struct xfs_busy_extent, list)->agno; -} diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index 3a7e7d8..93be4a6 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -23,7 +23,6 @@ struct xfs_btree_cur; struct xfs_mount; struct xfs_perag; struct xfs_trans; -struct xfs_busy_extent; extern struct workqueue_struct *xfs_alloc_wq; @@ -139,33 +138,6 @@ xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp, struct xfs_perag *pag); -#ifdef __KERNEL__ -void -xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, - xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags); - -void -xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, - bool do_discard); - -int -xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, - xfs_agblock_t bno, xfs_extlen_t len); - -void -xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, - xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); - -int -xfs_busy_extent_ag_cmp(void *priv, struct list_head *a, struct list_head *b); - -static inline void xfs_alloc_busy_sort(struct list_head *list) -{ - list_sort(NULL, list, xfs_busy_extent_ag_cmp); -} - -#endif /* __KERNEL__ */ - /* * Compute and fill in value of m_ag_maxlevels. */ diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c index e23cc97..3f66548 100644 --- a/fs/xfs/xfs_alloc_btree.c +++ b/fs/xfs/xfs_alloc_btree.c @@ -31,6 +31,7 @@ #include "xfs_inode.h" #include "xfs_btree.h" #include "xfs_alloc.h" +#include "xfs_extent_busy.h" #include "xfs_error.h" #include "xfs_trace.h" diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c index bbbabc8..e3f1abe 100644 --- a/fs/xfs/xfs_discard.c +++ b/fs/xfs/xfs_discard.c @@ -29,6 +29,7 @@ #include "xfs_inode.h" #include "xfs_alloc.h" #include "xfs_error.h" +#include "xfs_extent_busy.h" #include "xfs_discard.h" #include "xfs_trace.h" diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c new file mode 100644 index 0000000..4b5a4fa --- /dev/null +++ b/fs/xfs/xfs_extent_busy.c @@ -0,0 +1,603 @@ +/* + * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. + * Copyright (c) 2010 David Chinner. + * Copyright (c) 2011 Christoph Hellwig. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_types.h" +#include "xfs_log.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_ag.h" +#include "xfs_mount.h" +#include "xfs_bmap_btree.h" +#include "xfs_alloc.h" +#include "xfs_inode.h" +#include "xfs_extent_busy.h" +#include "xfs_trace.h" + +void +xfs_alloc_busy_insert( + struct xfs_trans *tp, + xfs_agnumber_t agno, + xfs_agblock_t bno, + xfs_extlen_t len, + unsigned int flags) +{ + struct xfs_busy_extent *new; + struct xfs_busy_extent *busyp; + struct xfs_perag *pag; + struct rb_node **rbp; + struct rb_node *parent = NULL; + + new = kmem_zalloc(sizeof(struct xfs_busy_extent), KM_MAYFAIL); + if (!new) { + /* + * No Memory! Since it is now not possible to track the free + * block, make this a synchronous transaction to insure that + * the block is not reused before this transaction commits. + */ + trace_xfs_alloc_busy_enomem(tp->t_mountp, agno, bno, len); + xfs_trans_set_sync(tp); + return; + } + + new->agno = agno; + new->bno = bno; + new->length = len; + INIT_LIST_HEAD(&new->list); + new->flags = flags; + + /* trace before insert to be able to see failed inserts */ + trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len); + + pag = xfs_perag_get(tp->t_mountp, new->agno); + spin_lock(&pag->pagb_lock); + rbp = &pag->pagb_tree.rb_node; + while (*rbp) { + parent = *rbp; + busyp = rb_entry(parent, struct xfs_busy_extent, rb_node); + + if (new->bno < busyp->bno) { + rbp = &(*rbp)->rb_left; + ASSERT(new->bno + new->length <= busyp->bno); + } else if (new->bno > busyp->bno) { + rbp = &(*rbp)->rb_right; + ASSERT(bno >= busyp->bno + busyp->length); + } else { + ASSERT(0); + } + } + + rb_link_node(&new->rb_node, parent, rbp); + rb_insert_color(&new->rb_node, &pag->pagb_tree); + + list_add(&new->list, &tp->t_busy); + spin_unlock(&pag->pagb_lock); + xfs_perag_put(pag); +} + +/* + * Search for a busy extent within the range of the extent we are about to + * allocate. You need to be holding the busy extent tree lock when calling + * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy + * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact + * match. This is done so that a non-zero return indicates an overlap that + * will require a synchronous transaction, but it can still be + * used to distinguish between a partial or exact match. + */ +int +xfs_alloc_busy_search( + struct xfs_mount *mp, + xfs_agnumber_t agno, + xfs_agblock_t bno, + xfs_extlen_t len) +{ + struct xfs_perag *pag; + struct rb_node *rbp; + struct xfs_busy_extent *busyp; + int match = 0; + + pag = xfs_perag_get(mp, agno); + spin_lock(&pag->pagb_lock); + + rbp = pag->pagb_tree.rb_node; + + /* find closest start bno overlap */ + while (rbp) { + busyp = rb_entry(rbp, struct xfs_busy_extent, rb_node); + if (bno < busyp->bno) { + /* may overlap, but exact start block is lower */ + if (bno + len > busyp->bno) + match = -1; + rbp = rbp->rb_left; + } else if (bno > busyp->bno) { + /* may overlap, but exact start block is higher */ + if (bno < busyp->bno + busyp->length) + match = -1; + rbp = rbp->rb_right; + } else { + /* bno matches busyp, length determines exact match */ + match = (busyp->length == len) ? 1 : -1; + break; + } + } + spin_unlock(&pag->pagb_lock); + xfs_perag_put(pag); + return match; +} + +/* + * The found free extent [fbno, fend] overlaps part or all of the given busy + * extent. If the overlap covers the beginning, the end, or all of the busy + * extent, the overlapping portion can be made unbusy and used for the + * allocation. We can't split a busy extent because we can't modify a + * transaction/CIL context busy list, but we can update an entries block + * number or length. + * + * Returns true if the extent can safely be reused, or false if the search + * needs to be restarted. + */ +STATIC bool +xfs_alloc_busy_update_extent( + struct xfs_mount *mp, + struct xfs_perag *pag, + struct xfs_busy_extent *busyp, + xfs_agblock_t fbno, + xfs_extlen_t flen, + bool userdata) +{ + xfs_agblock_t fend = fbno + flen; + xfs_agblock_t bbno = busyp->bno; + xfs_agblock_t bend = bbno + busyp->length; + + /* + * This extent is currently being discarded. Give the thread + * performing the discard a chance to mark the extent unbusy + * and retry. + */ + if (busyp->flags & XFS_ALLOC_BUSY_DISCARDED) { + spin_unlock(&pag->pagb_lock); + delay(1); + spin_lock(&pag->pagb_lock); + return false; + } + + /* + * If there is a busy extent overlapping a user allocation, we have + * no choice but to force the log and retry the search. + * + * Fortunately this does not happen during normal operation, but + * only if the filesystem is very low on space and has to dip into + * the AGFL for normal allocations. + */ + if (userdata) + goto out_force_log; + + if (bbno < fbno && bend > fend) { + /* + * Case 1: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +---------+ + * fbno fend + */ + + /* + * We would have to split the busy extent to be able to track + * it correct, which we cannot do because we would have to + * modify the list of busy extents attached to the transaction + * or CIL context, which is immutable. + * + * Force out the log to clear the busy extent and retry the + * search. + */ + goto out_force_log; + } else if (bbno >= fbno && bend <= fend) { + /* + * Case 2: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-----------------+ + * fbno fend + * + * Case 3: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +--------------------------+ + * fbno fend + * + * Case 4: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +--------------------------+ + * fbno fend + * + * Case 5: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-----------------------------------+ + * fbno fend + * + */ + + /* + * The busy extent is fully covered by the extent we are + * allocating, and can simply be removed from the rbtree. + * However we cannot remove it from the immutable list + * tracking busy extents in the transaction or CIL context, + * so set the length to zero to mark it invalid. + * + * We also need to restart the busy extent search from the + * tree root, because erasing the node can rearrange the + * tree topology. + */ + rb_erase(&busyp->rb_node, &pag->pagb_tree); + busyp->length = 0; + return false; + } else if (fend < bend) { + /* + * Case 6: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +---------+ + * fbno fend + * + * Case 7: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +------------------+ + * fbno fend + * + */ + busyp->bno = fend; + } else if (bbno < fbno) { + /* + * Case 8: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-------------+ + * fbno fend + * + * Case 9: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +----------------------+ + * fbno fend + */ + busyp->length = fbno - busyp->bno; + } else { + ASSERT(0); + } + + trace_xfs_alloc_busy_reuse(mp, pag->pag_agno, fbno, flen); + return true; + +out_force_log: + spin_unlock(&pag->pagb_lock); + xfs_log_force(mp, XFS_LOG_SYNC); + trace_xfs_alloc_busy_force(mp, pag->pag_agno, fbno, flen); + spin_lock(&pag->pagb_lock); + return false; +} + + +/* + * For a given extent [fbno, flen], make sure we can reuse it safely. + */ +void +xfs_alloc_busy_reuse( + struct xfs_mount *mp, + xfs_agnumber_t agno, + xfs_agblock_t fbno, + xfs_extlen_t flen, + bool userdata) +{ + struct xfs_perag *pag; + struct rb_node *rbp; + + ASSERT(flen > 0); + + pag = xfs_perag_get(mp, agno); + spin_lock(&pag->pagb_lock); +restart: + rbp = pag->pagb_tree.rb_node; + while (rbp) { + struct xfs_busy_extent *busyp = + rb_entry(rbp, struct xfs_busy_extent, rb_node); + xfs_agblock_t bbno = busyp->bno; + xfs_agblock_t bend = bbno + busyp->length; + + if (fbno + flen <= bbno) { + rbp = rbp->rb_left; + continue; + } else if (fbno >= bend) { + rbp = rbp->rb_right; + continue; + } + + if (!xfs_alloc_busy_update_extent(mp, pag, busyp, fbno, flen, + userdata)) + goto restart; + } + spin_unlock(&pag->pagb_lock); + xfs_perag_put(pag); +} + +/* + * For a given extent [fbno, flen], search the busy extent list to find a + * subset of the extent that is not busy. If *rlen is smaller than + * args->minlen no suitable extent could be found, and the higher level + * code needs to force out the log and retry the allocation. + */ +STATIC void +xfs_alloc_busy_trim( + struct xfs_alloc_arg *args, + xfs_agblock_t bno, + xfs_extlen_t len, + xfs_agblock_t *rbno, + xfs_extlen_t *rlen) +{ + xfs_agblock_t fbno; + xfs_extlen_t flen; + struct rb_node *rbp; + + ASSERT(len > 0); + + spin_lock(&args->pag->pagb_lock); +restart: + fbno = bno; + flen = len; + rbp = args->pag->pagb_tree.rb_node; + while (rbp && flen >= args->minlen) { + struct xfs_busy_extent *busyp = + rb_entry(rbp, struct xfs_busy_extent, rb_node); + xfs_agblock_t fend = fbno + flen; + xfs_agblock_t bbno = busyp->bno; + xfs_agblock_t bend = bbno + busyp->length; + + if (fend <= bbno) { + rbp = rbp->rb_left; + continue; + } else if (fbno >= bend) { + rbp = rbp->rb_right; + continue; + } + + /* + * If this is a metadata allocation, try to reuse the busy + * extent instead of trimming the allocation. + */ + if (!args->userdata && + !(busyp->flags & XFS_ALLOC_BUSY_DISCARDED)) { + if (!xfs_alloc_busy_update_extent(args->mp, args->pag, + busyp, fbno, flen, + false)) + goto restart; + continue; + } + + if (bbno <= fbno) { + /* start overlap */ + + /* + * Case 1: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +---------+ + * fbno fend + * + * Case 2: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-------------+ + * fbno fend + * + * Case 3: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-------------+ + * fbno fend + * + * Case 4: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-----------------+ + * fbno fend + * + * No unbusy region in extent, return failure. + */ + if (fend <= bend) + goto fail; + + /* + * Case 5: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +----------------------+ + * fbno fend + * + * Case 6: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +--------------------------+ + * fbno fend + * + * Needs to be trimmed to: + * +-------+ + * fbno fend + */ + fbno = bend; + } else if (bend >= fend) { + /* end overlap */ + + /* + * Case 7: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +------------------+ + * fbno fend + * + * Case 8: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +--------------------------+ + * fbno fend + * + * Needs to be trimmed to: + * +-------+ + * fbno fend + */ + fend = bbno; + } else { + /* middle overlap */ + + /* + * Case 9: + * bbno bend + * +BBBBBBBBBBBBBBBBB+ + * +-----------------------------------+ + * fbno fend + * + * Can be trimmed to: + * +-------+ OR +-------+ + * fbno fend fbno fend + * + * Backward allocation leads to significant + * fragmentation of directories, which degrades + * directory performance, therefore we always want to + * choose the option that produces forward allocation + * patterns. + * Preferring the lower bno extent will make the next + * request use "fend" as the start of the next + * allocation; if the segment is no longer busy at + * that point, we'll get a contiguous allocation, but + * even if it is still busy, we will get a forward + * allocation. + * We try to avoid choosing the segment at "bend", + * because that can lead to the next allocation + * taking the segment at "fbno", which would be a + * backward allocation. We only use the segment at + * "fbno" if it is much larger than the current + * requested size, because in that case there's a + * good chance subsequent allocations will be + * contiguous. + */ + if (bbno - fbno >= args->maxlen) { + /* left candidate fits perfect */ + fend = bbno; + } else if (fend - bend >= args->maxlen * 4) { + /* right candidate has enough free space */ + fbno = bend; + } else if (bbno - fbno >= args->minlen) { + /* left candidate fits minimum requirement */ + fend = bbno; + } else { + goto fail; + } + } + + flen = fend - fbno; + } + spin_unlock(&args->pag->pagb_lock); + + if (fbno != bno || flen != len) { + trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, + fbno, flen); + } + *rbno = fbno; + *rlen = flen; + return; +fail: + /* + * Return a zero extent length as failure indications. All callers + * re-check if the trimmed extent satisfies the minlen requirement. + */ + spin_unlock(&args->pag->pagb_lock); + trace_xfs_alloc_busy_trim(args->mp, args->agno, bno, len, fbno, 0); + *rbno = fbno; + *rlen = 0; +} + +static void +xfs_alloc_busy_clear_one( + struct xfs_mount *mp, + struct xfs_perag *pag, + struct xfs_busy_extent *busyp) +{ + if (busyp->length) { + trace_xfs_alloc_busy_clear(mp, busyp->agno, busyp->bno, + busyp->length); + rb_erase(&busyp->rb_node, &pag->pagb_tree); + } + + list_del_init(&busyp->list); + kmem_free(busyp); +} + +/* + * Remove all extents on the passed in list from the busy extents tree. + * If do_discard is set skip extents that need to be discarded, and mark + * these as undergoing a discard operation instead. + */ +void +xfs_alloc_busy_clear( + struct xfs_mount *mp, + struct list_head *list, + bool do_discard) +{ + struct xfs_busy_extent *busyp, *n; + struct xfs_perag *pag = NULL; + xfs_agnumber_t agno = NULLAGNUMBER; + + list_for_each_entry_safe(busyp, n, list, list) { + if (busyp->agno != agno) { + if (pag) { + spin_unlock(&pag->pagb_lock); + xfs_perag_put(pag); + } + pag = xfs_perag_get(mp, busyp->agno); + spin_lock(&pag->pagb_lock); + agno = busyp->agno; + } + + if (do_discard && busyp->length && + !(busyp->flags & XFS_ALLOC_BUSY_SKIP_DISCARD)) + busyp->flags = XFS_ALLOC_BUSY_DISCARDED; + else + xfs_alloc_busy_clear_one(mp, pag, busyp); + } + + if (pag) { + spin_unlock(&pag->pagb_lock); + xfs_perag_put(pag); + } +} + +/* + * Callback for list_sort to sort busy extents by the AG they reside in. + */ +int +xfs_alloc_busy_ag_cmp( + void *priv, + struct list_head *a, + struct list_head *b) +{ + return container_of(a, struct xfs_busy_extent, list)->agno - + container_of(b, struct xfs_busy_extent, list)->agno; +} diff --git a/fs/xfs/xfs_extent_busy.h b/fs/xfs/xfs_extent_busy.h new file mode 100644 index 0000000..671b501f --- /dev/null +++ b/fs/xfs/xfs_extent_busy.h @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. + * Copyright (c) 2010 David Chinner. + * Copyright (c) 2011 Christoph Hellwig. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_EXTENT_BUSY_H__ +#define __XFS_EXTENT_BUSY_H__ + +/* + * Busy block/extent entry. Indexed by a rbtree in perag to mark blocks that + * have been freed but whose transactions aren't committed to disk yet. + * + * Note that we use the transaction ID to record the transaction, not the + * transaction structure itself. See xfs_extent_busy_insert() for details. + */ +struct xfs_busy_extent { + struct rb_node rb_node; /* ag by-bno indexed search tree */ + struct list_head list; /* transaction busy extent list */ + xfs_agnumber_t agno; + xfs_agblock_t bno; + xfs_extlen_t length; + unsigned int flags; +#define XFS_ALLOC_BUSY_DISCARDED 0x01 /* undergoing a discard op. */ +#define XFS_ALLOC_BUSY_SKIP_DISCARD 0x02 /* do not discard */ +}; + +void +xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno, + xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags); + +void +xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list, + bool do_discard); + +int +xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, + xfs_agblock_t bno, xfs_extlen_t len); + +void +xfs_alloc_busy_reuse(struct xfs_mount *mp, xfs_agnumber_t agno, + xfs_agblock_t fbno, xfs_extlen_t flen, bool userdata); + +int +xfs_alloc_busy_ag_cmp(void *priv, struct list_head *a, struct list_head *b); + +static inline void xfs_alloc_busy_sort(struct list_head *list) +{ + list_sort(NULL, list, xfs_alloc_busy_ag_cmp); +} + +#endif /* __XFS_EXTENT_BUSY_H__ */ diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 47b139b..a6e3e71 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -28,6 +28,7 @@ #include "xfs_mount.h" #include "xfs_error.h" #include "xfs_alloc.h" +#include "xfs_extent_busy.h" #include "xfs_discard.h" /* diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index d7acb7b..d8bdb61 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -35,6 +35,7 @@ #include "xfs_btree.h" #include "xfs_ialloc.h" #include "xfs_alloc.h" +#include "xfs_extent_busy.h" #include "xfs_bmap.h" #include "xfs_quota.h" #include "xfs_trans_priv.h" |
