diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 37c4952..ff54ef4 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -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_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 @@
 		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_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 @@
 		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 @@
 	 *
 	 * 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 @@
 	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 @@
 		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_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_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_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 @@
 
 	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 @@
 			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 @@
 			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 @@
 			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 @@
 			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 @@
 	 * 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 @@
 		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 @@
 	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 @@
 			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 @@
 	 * 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 @@
 	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 @@
 	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,