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xfs: do not immediately reuse busy extent ranges

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Every time we reallocate a busy extent, we cause a synchronous log force
to occur to ensure the freeing transaction is on disk before we continue
and use the newly allocated extent.  This is extremely sub-optimal as we
have to mark every transaction with blocks that get reused as synchronous.

Instead of searching the busy extent list after deciding on the extent to
allocate, check each candidate extent during the allocation decisions as
to whether they are in the busy list.  If they are in the busy list, we
trim the busy range out of the extent we have found and determine if that
trimmed range is still OK for allocation. In many cases, this check can
be incorporated into the allocation extent alignment code which already
does trimming of the found extent before determining if it is a valid
candidate for allocation.

Based on earlier patches from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
tirimbino
Christoph Hellwig 14 years ago committed by Alex Elder
parent a870acd9b2
commit e26f0501cf
2 changed files with 361 additions and 79 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 33
      fs/xfs/linux-2.6/xfs_trace.h
  2. 407
      fs/xfs/xfs_alloc.c

33
fs/xfs/linux-2.6/xfs_trace.h
Unescape View File

@ -1241,6 +1241,36 @@ TRACE_EVENT(xfs_alloc_busysearch,
__print_symbolic(__entry->found, XFS_BUSY_STATES))
);
TRACE_EVENT(xfs_alloc_busy_trim,
TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno,
xfs_agblock_t agbno, xfs_extlen_t len,
xfs_agblock_t tbno, xfs_extlen_t tlen),
TP_ARGS(mp, agno, agbno, len, tbno, tlen),
TP_STRUCT__entry(
__field(dev_t, dev)
__field(xfs_agnumber_t, agno)
__field(xfs_agblock_t, agbno)
__field(xfs_extlen_t, len)
__field(xfs_agblock_t, tbno)
__field(xfs_extlen_t, tlen)
),
TP_fast_assign(
__entry->dev = mp->m_super->s_dev;
__entry->agno = agno;
__entry->agbno = agbno;
__entry->len = len;
__entry->tbno = tbno;
__entry->tlen = tlen;
),
TP_printk("dev %d:%d agno %u agbno %u len %u tbno %u tlen %u",
MAJOR(__entry->dev), MINOR(__entry->dev),
__entry->agno,
__entry->agbno,
__entry->len,
__entry->tbno,
__entry->tlen)
);
TRACE_EVENT(xfs_trans_commit_lsn,
TP_PROTO(struct xfs_trans *trans),
TP_ARGS(trans),
@ -1433,11 +1463,14 @@ DEFINE_ALLOC_EVENT(xfs_alloc_near_first);
DEFINE_ALLOC_EVENT(xfs_alloc_near_greater);
DEFINE_ALLOC_EVENT(xfs_alloc_near_lesser);
DEFINE_ALLOC_EVENT(xfs_alloc_near_error);
DEFINE_ALLOC_EVENT(xfs_alloc_near_noentry);
DEFINE_ALLOC_EVENT(xfs_alloc_near_busy);
DEFINE_ALLOC_EVENT(xfs_alloc_size_neither);
DEFINE_ALLOC_EVENT(xfs_alloc_size_noentry);
DEFINE_ALLOC_EVENT(xfs_alloc_size_nominleft);
DEFINE_ALLOC_EVENT(xfs_alloc_size_done);
DEFINE_ALLOC_EVENT(xfs_alloc_size_error);
DEFINE_ALLOC_EVENT(xfs_alloc_size_busy);
DEFINE_ALLOC_EVENT(xfs_alloc_small_freelist);
DEFINE_ALLOC_EVENT(xfs_alloc_small_notenough);
DEFINE_ALLOC_EVENT(xfs_alloc_small_done);

407
fs/xfs/xfs_alloc.c
Unescape View File

@ -41,19 +41,13 @@
#define XFSA_FIXUP_BNO_OK 1
#define XFSA_FIXUP_CNT_OK 2
/*
* Prototypes for per-ag allocation routines
*/
STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
/*
* Internal functions.
*/
xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
STATIC void xfs_alloc_busy_trim(struct xfs_alloc_arg *,
xfs_agblock_t, xfs_extlen_t, xfs_agblock_t *, xfs_extlen_t *);
/*
* Lookup the record equal to [bno, len] in the btree given by cur.
@ -154,19 +148,21 @@ xfs_alloc_compute_aligned(
xfs_extlen_t *reslen) /* result length */
{
xfs_agblock_t bno;
xfs_extlen_t diff;
xfs_extlen_t len;
if (args->alignment > 1 && foundlen >= args->minlen) {
bno = roundup(foundbno, args->alignment);
diff = bno - foundbno;
len = diff >= foundlen ? 0 : foundlen - diff;
/* Trim busy sections out of found extent */
xfs_alloc_busy_trim(args, foundbno, foundlen, &bno, &len);
if (args->alignment > 1 && len >= args->minlen) {
xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
xfs_extlen_t diff = aligned_bno - bno;
*resbno = aligned_bno;
*reslen = diff >= len ? 0 : len - diff;
} else {
bno = foundbno;
len = foundlen;
*resbno = bno;
*reslen = len;
}
*resbno = bno;
*reslen = len;
}
/*
@ -541,16 +537,8 @@ xfs_alloc_ag_vextent(
if (error)
return error;
/*
* Search the busylist for these blocks and mark the
* transaction as synchronous if blocks are found. This
* avoids the need to block due to a synchronous log
* force to ensure correct ordering as the synchronous
* transaction will guarantee that for us.
*/
if (xfs_alloc_busy_search(args->mp, args->agno,
args->agbno, args->len))
xfs_trans_set_sync(args->tp);
ASSERT(!xfs_alloc_busy_search(args->mp, args->agno,
args->agbno, args->len));
}
if (!args->isfl) {
@ -577,14 +565,14 @@ xfs_alloc_ag_vextent_exact(
{
xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
xfs_agblock_t end; /* end of allocated extent */
int error;
xfs_agblock_t fbno; /* start block of found extent */
xfs_agblock_t fend; /* end block of found extent */
xfs_extlen_t flen; /* length of found extent */
xfs_agblock_t tbno; /* start block of trimmed extent */
xfs_extlen_t tlen; /* length of trimmed extent */
xfs_agblock_t tend; /* end block of trimmed extent */
xfs_agblock_t end; /* end of allocated extent */
int i; /* success/failure of operation */
xfs_agblock_t maxend; /* end of maximal extent */
xfs_agblock_t minend; /* end of minimal extent */
xfs_extlen_t rlen; /* length of returned extent */
ASSERT(args->alignment == 1);
@ -614,14 +602,22 @@ xfs_alloc_ag_vextent_exact(
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
ASSERT(fbno <= args->agbno);
minend = args->agbno + args->minlen;
maxend = args->agbno + args->maxlen;
fend = fbno + flen;
/*
* Give up if the freespace isn't long enough for the minimum request.
* Check for overlapping busy extents.
*/
if (fend < minend)
xfs_alloc_busy_trim(args, fbno, flen, &tbno, &tlen);
/*
* Give up if the start of the extent is busy, or the freespace isn't
* long enough for the minimum request.
*/
if (tbno > args->agbno)
goto not_found;
if (tlen < args->minlen)
goto not_found;
tend = tbno + tlen;
if (tend < args->agbno + args->minlen)
goto not_found;
/*
@ -630,14 +626,14 @@ xfs_alloc_ag_vextent_exact(
*
* Fix the length according to mod and prod if given.
*/
end = XFS_AGBLOCK_MIN(fend, maxend);
end = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen);
args->len = end - args->agbno;
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args))
goto not_found;
rlen = args->len;
ASSERT(args->agbno + rlen <= fend);
ASSERT(args->agbno + rlen <= tend);
end = args->agbno + rlen;
/*
@ -686,11 +682,11 @@ xfs_alloc_find_best_extent(
struct xfs_btree_cur **scur, /* searching cursor */
xfs_agblock_t gdiff, /* difference for search comparison */
xfs_agblock_t *sbno, /* extent found by search */
xfs_extlen_t *slen,
xfs_extlen_t *slena, /* aligned length */
xfs_extlen_t *slen, /* extent length */
xfs_agblock_t *sbnoa, /* aligned extent found by search */
xfs_extlen_t *slena, /* aligned extent length */
int dir) /* 0 = search right, 1 = search left */
{
xfs_agblock_t bno;
xfs_agblock_t new;
xfs_agblock_t sdiff;
int error;
@ -708,16 +704,16 @@ xfs_alloc_find_best_extent(
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_alloc_compute_aligned(args, *sbno, *slen, &bno, slena);
xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
/*
* The good extent is closer than this one.
*/
if (!dir) {
if (bno >= args->agbno + gdiff)
if (*sbnoa >= args->agbno + gdiff)
goto out_use_good;
} else {
if (bno <= args->agbno - gdiff)
if (*sbnoa <= args->agbno - gdiff)
goto out_use_good;
}
@ -729,8 +725,8 @@ xfs_alloc_find_best_extent(
xfs_alloc_fix_len(args);
sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, *sbno,
*slen, &new);
args->alignment, *sbnoa,
*slena, &new);
/*
* Choose closer size and invalidate other cursor.
@ -780,7 +776,7 @@ xfs_alloc_ag_vextent_near(
xfs_agblock_t gtbnoa; /* aligned ... */
xfs_extlen_t gtdiff; /* difference to right side entry */
xfs_extlen_t gtlen; /* length of right side entry */
xfs_extlen_t gtlena = 0; /* aligned ... */
xfs_extlen_t gtlena; /* aligned ... */
xfs_agblock_t gtnew; /* useful start bno of right side */
int error; /* error code */
int i; /* result code, temporary */
@ -789,9 +785,10 @@ xfs_alloc_ag_vextent_near(
xfs_agblock_t ltbnoa; /* aligned ... */
xfs_extlen_t ltdiff; /* difference to left side entry */
xfs_extlen_t ltlen; /* length of left side entry */
xfs_extlen_t ltlena = 0; /* aligned ... */
xfs_extlen_t ltlena; /* aligned ... */
xfs_agblock_t ltnew; /* useful start bno of left side */
xfs_extlen_t rlen; /* length of returned extent */
int forced = 0;
#if defined(DEBUG) && defined(__KERNEL__)
/*
* Randomly don't execute the first algorithm.
@ -800,13 +797,20 @@ xfs_alloc_ag_vextent_near(
dofirst = random32() & 1;
#endif
restart:
bno_cur_lt = NULL;
bno_cur_gt = NULL;
ltlen = 0;
gtlena = 0;
ltlena = 0;
/*
* Get a cursor for the by-size btree.
*/
cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT);
ltlen = 0;
bno_cur_lt = bno_cur_gt = NULL;
/*
* See if there are any free extents as big as maxlen.
*/
@ -822,11 +826,13 @@ xfs_alloc_ag_vextent_near(
goto error0;
if (i == 0 || ltlen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
trace_xfs_alloc_near_noentry(args);
return 0;
}
ASSERT(i == 1);
}
args->wasfromfl = 0;
/*
* First algorithm.
* If the requested extent is large wrt the freespaces available
@ -890,7 +896,7 @@ xfs_alloc_ag_vextent_near(
if (args->len < blen)
continue;
ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, ltbno, ltlen, &ltnew);
args->alignment, ltbnoa, ltlena, &ltnew);
if (ltnew != NULLAGBLOCK &&
(args->len > blen || ltdiff < bdiff)) {
bdiff = ltdiff;
@ -1042,11 +1048,12 @@ xfs_alloc_ag_vextent_near(
args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
xfs_alloc_fix_len(args);
ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, ltbno, ltlen, &ltnew);
args->alignment, ltbnoa, ltlena, &ltnew);
error = xfs_alloc_find_best_extent(args,
&bno_cur_lt, &bno_cur_gt,
ltdiff, &gtbno, &gtlen, &gtlena,
ltdiff, &gtbno, &gtlen,
&gtbnoa, &gtlena,
0 /* search right */);
} else {
ASSERT(gtlena >= args->minlen);
@ -1057,11 +1064,12 @@ xfs_alloc_ag_vextent_near(
args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
xfs_alloc_fix_len(args);
gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
args->alignment, gtbno, gtlen, &gtnew);
args->alignment, gtbnoa, gtlena, &gtnew);
error = xfs_alloc_find_best_extent(args,
&bno_cur_gt, &bno_cur_lt,
gtdiff, &ltbno, &ltlen, &ltlena,
gtdiff, &ltbno, &ltlen,
&ltbnoa, &ltlena,
1 /* search left */);
}
@ -1073,6 +1081,12 @@ xfs_alloc_ag_vextent_near(
* If we couldn't get anything, give up.
*/
if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
if (!forced++) {
trace_xfs_alloc_near_busy(args);
xfs_log_force(args->mp, XFS_LOG_SYNC);
goto restart;
}
trace_xfs_alloc_size_neither(args);
args->agbno = NULLAGBLOCK;
return 0;
@ -1107,12 +1121,13 @@ xfs_alloc_ag_vextent_near(
return 0;
}
rlen = args->len;
(void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, ltbno,
ltlen, &ltnew);
(void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
ltbnoa, ltlena, &ltnew);
ASSERT(ltnew >= ltbno);
ASSERT(ltnew + rlen <= ltbno + ltlen);
ASSERT(ltnew + rlen <= ltbnoa + ltlena);
ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
args->agbno = ltnew;
if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
ltnew, rlen, XFSA_FIXUP_BNO_OK)))
goto error0;
@ -1155,26 +1170,35 @@ xfs_alloc_ag_vextent_size(
int i; /* temp status variable */
xfs_agblock_t rbno; /* returned block number */
xfs_extlen_t rlen; /* length of returned extent */
int forced = 0;
restart:
/*
* Allocate and initialize a cursor for the by-size btree.
*/
cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
args->agno, XFS_BTNUM_CNT);
bno_cur = NULL;
/*
* Look for an entry >= maxlen+alignment-1 blocks.
*/
if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
args->maxlen + args->alignment - 1, &i)))
goto error0;
/*
* If none, then pick up the last entry in the tree unless the
* tree is empty.
* If none or we have busy extents that we cannot allocate from, then
* we have to settle for a smaller extent. In the case that there are
* no large extents, this will return the last entry in the tree unless
* the tree is empty. In the case that there are only busy large
* extents, this will return the largest small extent unless there
* are no smaller extents available.
*/
if (!i) {
if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno,
&flen, &i)))
if (!i || forced > 1) {
error = xfs_alloc_ag_vextent_small(args, cnt_cur,
&fbno, &flen, &i);
if (error)
goto error0;
if (i == 0 || flen == 0) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
@ -1182,22 +1206,56 @@ xfs_alloc_ag_vextent_size(
return 0;
}
ASSERT(i == 1);
xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
} else {
/*
* Search for a non-busy extent that is large enough.
* If we are at low space, don't check, or if we fall of
* the end of the btree, turn off the busy check and
* restart.
*/
for (;;) {
error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
xfs_alloc_compute_aligned(args, fbno, flen,
&rbno, &rlen);
if (rlen >= args->maxlen)
break;
error = xfs_btree_increment(cnt_cur, 0, &i);
if (error)
goto error0;
if (i == 0) {
/*
* Our only valid extents must have been busy.
* Make it unbusy by forcing the log out and
* retrying. If we've been here before, forcing
* the log isn't making the extents available,
* which means they have probably been freed in
* this transaction. In that case, we have to
* give up on them and we'll attempt a minlen
* allocation the next time around.
*/
xfs_btree_del_cursor(cnt_cur,
XFS_BTREE_NOERROR);
trace_xfs_alloc_size_busy(args);
if (!forced++)
xfs_log_force(args->mp, XFS_LOG_SYNC);
goto restart;
}
}
}
/*
* There's a freespace as big as maxlen+alignment-1, get it.
*/
else {
if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
/*
* In the first case above, we got the last entry in the
* by-size btree. Now we check to see if the space hits maxlen
* once aligned; if not, we search left for something better.
* This can't happen in the second case above.
*/
xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
(rlen <= flen && rbno + rlen <= fbno + flen), error0);
@ -1251,13 +1309,19 @@ xfs_alloc_ag_vextent_size(
* Fix up the length.
*/
args->len = rlen;
xfs_alloc_fix_len(args);
if (rlen < args->minlen || !xfs_alloc_fix_minleft(args)) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
trace_xfs_alloc_size_nominleft(args);
args->agbno = NULLAGBLOCK;
return 0;
if (rlen < args->minlen) {
if (!forced++) {
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
trace_xfs_alloc_size_busy(args);
xfs_log_force(args->mp, XFS_LOG_SYNC);
goto restart;
}
goto out_nominleft;
}
xfs_alloc_fix_len(args);
if (!xfs_alloc_fix_minleft(args))
goto out_nominleft;
rlen = args->len;
XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
/*
@ -1287,6 +1351,12 @@ error0:
if (bno_cur)
xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
return error;
out_nominleft:
xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
trace_xfs_alloc_size_nominleft(args);
args->agbno = NULLAGBLOCK;
return 0;
}
/*
@ -2650,6 +2720,185 @@ xfs_alloc_busy_search(
return match;
}
/*
* 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 = bno;
xfs_extlen_t flen = len;
struct rb_node *rbp;
ASSERT(flen > 0);
spin_lock(&args->pag->pagb_lock);
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 (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;
}
void
xfs_alloc_busy_clear(
struct xfs_mount *mp,

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