1 files changed, 250 insertions, 295 deletions

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 112abc439ca..27d64d752ea 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -41,10 +41,6 @@
 #define	XFSA_FIXUP_BNO_OK	1
 #define	XFSA_FIXUP_CNT_OK	2
 
-static int
-xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno,
-		    xfs_agblock_t bno, xfs_extlen_t len);
-
 /*
  * Prototypes for per-ag allocation routines
  */
@@ -94,7 +90,7 @@ xfs_alloc_lookup_ge(
  * Lookup the first record less than or equal to [bno, len]
  * in the btree given by cur.
  */
-STATIC int				/* error */
+int					/* error */
 xfs_alloc_lookup_le(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
 	xfs_agblock_t		bno,	/* starting block of extent */
@@ -127,7 +123,7 @@ xfs_alloc_update(
 /*
  * Get the data from the pointed-to record.
  */
-STATIC int				/* error */
+int					/* error */
 xfs_alloc_get_rec(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
 	xfs_agblock_t		*bno,	/* output: starting block of extent */
@@ -151,10 +147,9 @@ xfs_alloc_get_rec(
  */
 STATIC void
 xfs_alloc_compute_aligned(
+	xfs_alloc_arg_t	*args,		/* allocation argument structure */
 	xfs_agblock_t	foundbno,	/* starting block in found extent */
 	xfs_extlen_t	foundlen,	/* length in found extent */
-	xfs_extlen_t	alignment,	/* alignment for allocation */
-	xfs_extlen_t	minlen,		/* minimum length for allocation */
 	xfs_agblock_t	*resbno,	/* result block number */
 	xfs_extlen_t	*reslen)	/* result length */
 {
@@ -162,8 +157,8 @@ xfs_alloc_compute_aligned(
 	xfs_extlen_t	diff;
 	xfs_extlen_t	len;
 
-	if (alignment > 1 && foundlen >= minlen) {
-		bno = roundup(foundbno, alignment);
+	if (args->alignment > 1 && foundlen >= args->minlen) {
+		bno = roundup(foundbno, args->alignment);
 		diff = bno - foundbno;
 		len = diff >= foundlen ? 0 : foundlen - diff;
 	} else {
@@ -468,6 +463,27 @@ xfs_alloc_read_agfl(
 	return 0;
 }
 
+STATIC int
+xfs_alloc_update_counters(
+	struct xfs_trans	*tp,
+	struct xfs_perag	*pag,
+	struct xfs_buf		*agbp,
+	long			len)
+{
+	struct xfs_agf		*agf = XFS_BUF_TO_AGF(agbp);
+
+	pag->pagf_freeblks += len;
+	be32_add_cpu(&agf->agf_freeblks, len);
+
+	xfs_trans_agblocks_delta(tp, len);
+	if (unlikely(be32_to_cpu(agf->agf_freeblks) >
+		     be32_to_cpu(agf->agf_length)))
+		return EFSCORRUPTED;
+
+	xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
+	return 0;
+}
+
 /*
  * Allocation group level functions.
  */
@@ -509,49 +525,44 @@ xfs_alloc_ag_vextent(
 		ASSERT(0);
 		/* NOTREACHED */
 	}
-	if (error)
+
+	if (error || args->agbno == NULLAGBLOCK)
 		return error;
-	/*
-	 * If the allocation worked, need to change the agf structure
-	 * (and log it), and the superblock.
-	 */
-	if (args->agbno != NULLAGBLOCK) {
-		xfs_agf_t	*agf;	/* allocation group freelist header */
-		long		slen = (long)args->len;
 
-		ASSERT(args->len >= args->minlen && args->len <= args->maxlen);
-		ASSERT(!(args->wasfromfl) || !args->isfl);
-		ASSERT(args->agbno % args->alignment == 0);
-		if (!(args->wasfromfl)) {
-
-			agf = XFS_BUF_TO_AGF(args->agbp);
-			be32_add_cpu(&agf->agf_freeblks, -(args->len));
-			xfs_trans_agblocks_delta(args->tp,
-						 -((long)(args->len)));
-			args->pag->pagf_freeblks -= args->len;
-			ASSERT(be32_to_cpu(agf->agf_freeblks) <=
-				be32_to_cpu(agf->agf_length));
-			xfs_alloc_log_agf(args->tp, args->agbp,
-						XFS_AGF_FREEBLKS);
-			/*
-			 * 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);
-		}
-		if (!args->isfl)
-			xfs_trans_mod_sb(args->tp,
-				args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
-					XFS_TRANS_SB_FDBLOCKS, -slen);
-		XFS_STATS_INC(xs_allocx);
-		XFS_STATS_ADD(xs_allocb, args->len);
+	ASSERT(args->len >= args->minlen);
+	ASSERT(args->len <= args->maxlen);
+	ASSERT(!args->wasfromfl || !args->isfl);
+	ASSERT(args->agbno % args->alignment == 0);
+
+	if (!args->wasfromfl) {
+		error = xfs_alloc_update_counters(args->tp, args->pag,
+						  args->agbp,
+						  -((long)(args->len)));
+		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);
 	}
-	return 0;
+
+	if (!args->isfl) {
+		xfs_trans_mod_sb(args->tp, args->wasdel ?
+				 XFS_TRANS_SB_RES_FDBLOCKS :
+				 XFS_TRANS_SB_FDBLOCKS,
+				 -((long)(args->len)));
+	}
+
+	XFS_STATS_INC(xs_allocx);
+	XFS_STATS_ADD(xs_allocb, args->len);
+	return error;
 }
 
 /*
@@ -577,61 +588,58 @@ xfs_alloc_ag_vextent_exact(
 	xfs_extlen_t	rlen;	/* length of returned extent */
 
 	ASSERT(args->alignment == 1);
+
 	/*
 	 * Allocate/initialize a cursor for the by-number freespace btree.
 	 */
 	bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
-		args->agno, XFS_BTNUM_BNO);
+					  args->agno, XFS_BTNUM_BNO);
+
 	/*
 	 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
 	 * Look for the closest free block <= bno, it must contain bno
 	 * if any free block does.
 	 */
-	if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
+	error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
+	if (error)
 		goto error0;
-	if (!i) {
-		/*
-		 * Didn't find it, return null.
-		 */
-		xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-		args->agbno = NULLAGBLOCK;
-		return 0;
-	}
+	if (!i)
+		goto not_found;
+
 	/*
 	 * Grab the freespace record.
 	 */
-	if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
+	error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
+	if (error)
 		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.
 	 */
-	if (fend < minend) {
-		xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-		args->agbno = NULLAGBLOCK;
-		return 0;
-	}
+	if (fend < minend)
+		goto not_found;
+
 	/*
 	 * End of extent will be smaller of the freespace end and the
 	 * maximal requested end.
-	 */
-	end = XFS_AGBLOCK_MIN(fend, maxend);
-	/*
+	 *
 	 * Fix the length according to mod and prod if given.
 	 */
+	end = XFS_AGBLOCK_MIN(fend, maxend);
 	args->len = end - args->agbno;
 	xfs_alloc_fix_len(args);
-	if (!xfs_alloc_fix_minleft(args)) {
-		xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
-		return 0;
-	}
+	if (!xfs_alloc_fix_minleft(args))
+		goto not_found;
+
 	rlen = args->len;
 	ASSERT(args->agbno + rlen <= fend);
 	end = args->agbno + rlen;
+
 	/*
 	 * We are allocating agbno for rlen [agbno .. end]
 	 * Allocate/initialize a cursor for the by-size btree.
@@ -640,16 +648,25 @@ xfs_alloc_ag_vextent_exact(
 		args->agno, XFS_BTNUM_CNT);
 	ASSERT(args->agbno + args->len <=
 		be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
-	if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
-			args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
+	error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
+				      args->len, XFSA_FIXUP_BNO_OK);
+	if (error) {
 		xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
 		goto error0;
 	}
+
 	xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
 	xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 
-	trace_xfs_alloc_exact_done(args);
 	args->wasfromfl = 0;
+	trace_xfs_alloc_exact_done(args);
+	return 0;
+
+not_found:
+	/* Didn't find it, return null. */
+	xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
+	args->agbno = NULLAGBLOCK;
+	trace_xfs_alloc_exact_notfound(args);
 	return 0;
 
 error0:
@@ -659,6 +676,94 @@ error0:
 }
 
 /*
+ * Search the btree in a given direction via the search cursor and compare
+ * the records found against the good extent we've already found.
+ */
+STATIC int
+xfs_alloc_find_best_extent(
+	struct xfs_alloc_arg	*args,	/* allocation argument structure */
+	struct xfs_btree_cur	**gcur,	/* good cursor */
+	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 */
+	int			dir)	/* 0 = search right, 1 = search left */
+{
+	xfs_agblock_t		bno;
+	xfs_agblock_t		new;
+	xfs_agblock_t		sdiff;
+	int			error;
+	int			i;
+
+	/* The good extent is perfect, no need to  search. */
+	if (!gdiff)
+		goto out_use_good;
+
+	/*
+	 * Look until we find a better one, run out of space or run off the end.
+	 */
+	do {
+		error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
+		if (error)
+			goto error0;
+		XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
+		xfs_alloc_compute_aligned(args, *sbno, *slen, &bno, slena);
+
+		/*
+		 * The good extent is closer than this one.
+		 */
+		if (!dir) {
+			if (bno >= args->agbno + gdiff)
+				goto out_use_good;
+		} else {
+			if (bno <= args->agbno - gdiff)
+				goto out_use_good;
+		}
+
+		/*
+		 * Same distance, compare length and pick the best.
+		 */
+		if (*slena >= args->minlen) {
+			args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
+			xfs_alloc_fix_len(args);
+
+			sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
+						       args->alignment, *sbno,
+						       *slen, &new);
+
+			/*
+			 * Choose closer size and invalidate other cursor.
+			 */
+			if (sdiff < gdiff)
+				goto out_use_search;
+			goto out_use_good;
+		}
+
+		if (!dir)
+			error = xfs_btree_increment(*scur, 0, &i);
+		else
+			error = xfs_btree_decrement(*scur, 0, &i);
+		if (error)
+			goto error0;
+	} while (i);
+
+out_use_good:
+	xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
+	*scur = NULL;
+	return 0;
+
+out_use_search:
+	xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
+	*gcur = NULL;
+	return 0;
+
+error0:
+	/* caller invalidates cursors */
+	return error;
+}
+
+/*
  * Allocate a variable extent near bno in the allocation group agno.
  * Extent's length (returned in len) will be between minlen and maxlen,
  * and of the form k * prod + mod unless there's nothing that large.
@@ -775,8 +880,8 @@ xfs_alloc_ag_vextent_near(
 			if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
 				goto error0;
 			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-			xfs_alloc_compute_aligned(ltbno, ltlen, args->alignment,
-					args->minlen, &ltbnoa, &ltlena);
+			xfs_alloc_compute_aligned(args, ltbno, ltlen,
+						  &ltbnoa, &ltlena);
 			if (ltlena < args->minlen)
 				continue;
 			args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
@@ -896,8 +1001,8 @@ xfs_alloc_ag_vextent_near(
 			if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
 				goto error0;
 			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-			xfs_alloc_compute_aligned(ltbno, ltlen, args->alignment,
-					args->minlen, &ltbnoa, &ltlena);
+			xfs_alloc_compute_aligned(args, ltbno, ltlen,
+						  &ltbnoa, &ltlena);
 			if (ltlena >= args->minlen)
 				break;
 			if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
@@ -912,8 +1017,8 @@ xfs_alloc_ag_vextent_near(
 			if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
 				goto error0;
 			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-			xfs_alloc_compute_aligned(gtbno, gtlen, args->alignment,
-					args->minlen, &gtbnoa, &gtlena);
+			xfs_alloc_compute_aligned(args, gtbno, gtlen,
+						  &gtbnoa, &gtlena);
 			if (gtlena >= args->minlen)
 				break;
 			if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
@@ -925,203 +1030,45 @@ xfs_alloc_ag_vextent_near(
 			}
 		}
 	} while (bno_cur_lt || bno_cur_gt);
+
 	/*
 	 * Got both cursors still active, need to find better entry.
 	 */
 	if (bno_cur_lt && bno_cur_gt) {
-		/*
-		 * Left side is long enough, look for a right side entry.
-		 */
 		if (ltlena >= args->minlen) {
 			/*
-			 * Fix up the length.
+			 * Left side is good, look for a right side entry.
 			 */
 			args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
 			xfs_alloc_fix_len(args);
-			rlen = args->len;
-			ltdiff = xfs_alloc_compute_diff(args->agbno, rlen,
+			ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
 				args->alignment, ltbno, ltlen, &ltnew);
+
+			error = xfs_alloc_find_best_extent(args,
+						&bno_cur_lt, &bno_cur_gt,
+						ltdiff, &gtbno, &gtlen, &gtlena,
+						0 /* search right */);
+		} else {
+			ASSERT(gtlena >= args->minlen);
+
 			/*
-			 * Not perfect.
-			 */
-			if (ltdiff) {
-				/*
-				 * Look until we find a better one, run out of
-				 * space, or run off the end.
-				 */
-				while (bno_cur_lt && bno_cur_gt) {
-					if ((error = xfs_alloc_get_rec(
-							bno_cur_gt, &gtbno,
-							&gtlen, &i)))
-						goto error0;
-					XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-					xfs_alloc_compute_aligned(gtbno, gtlen,
-						args->alignment, args->minlen,
-						&gtbnoa, &gtlena);
-					/*
-					 * The left one is clearly better.
-					 */
-					if (gtbnoa >= args->agbno + ltdiff) {
-						xfs_btree_del_cursor(
-							bno_cur_gt,
-							XFS_BTREE_NOERROR);
-						bno_cur_gt = NULL;
-						break;
-					}
-					/*
-					 * If we reach a big enough entry,
-					 * compare the two and pick the best.
-					 */
-					if (gtlena >= args->minlen) {
-						args->len =
-							XFS_EXTLEN_MIN(gtlena,
-								args->maxlen);
-						xfs_alloc_fix_len(args);
-						rlen = args->len;
-						gtdiff = xfs_alloc_compute_diff(
-							args->agbno, rlen,
-							args->alignment,
-							gtbno, gtlen, &gtnew);
-						/*
-						 * Right side is better.
-						 */
-						if (gtdiff < ltdiff) {
-							xfs_btree_del_cursor(
-								bno_cur_lt,
-								XFS_BTREE_NOERROR);
-							bno_cur_lt = NULL;
-						}
-						/*
-						 * Left side is better.
-						 */
-						else {
-							xfs_btree_del_cursor(
-								bno_cur_gt,
-								XFS_BTREE_NOERROR);
-							bno_cur_gt = NULL;
-						}
-						break;
-					}
-					/*
-					 * Fell off the right end.
-					 */
-					if ((error = xfs_btree_increment(
-							bno_cur_gt, 0, &i)))
-						goto error0;
-					if (!i) {
-						xfs_btree_del_cursor(
-							bno_cur_gt,
-							XFS_BTREE_NOERROR);
-						bno_cur_gt = NULL;
-						break;
-					}
-				}
-			}
-			/*
-			 * The left side is perfect, trash the right side.
-			 */
-			else {
-				xfs_btree_del_cursor(bno_cur_gt,
-						     XFS_BTREE_NOERROR);
-				bno_cur_gt = NULL;
-			}
-		}
-		/*
-		 * It's the right side that was found first, look left.
-		 */
-		else {
-			/*
-			 * Fix up the length.
+			 * Right side is good, look for a left side entry.
 			 */
 			args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
 			xfs_alloc_fix_len(args);
-			rlen = args->len;
-			gtdiff = xfs_alloc_compute_diff(args->agbno, rlen,
+			gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
 				args->alignment, gtbno, gtlen, &gtnew);
-			/*
-			 * Right side entry isn't perfect.
-			 */
-			if (gtdiff) {
-				/*
-				 * Look until we find a better one, run out of
-				 * space, or run off the end.
-				 */
-				while (bno_cur_lt && bno_cur_gt) {
-					if ((error = xfs_alloc_get_rec(
-							bno_cur_lt, &ltbno,
-							&ltlen, &i)))
-						goto error0;
-					XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
-					xfs_alloc_compute_aligned(ltbno, ltlen,
-						args->alignment, args->minlen,
-						&ltbnoa, &ltlena);
-					/*
-					 * The right one is clearly better.
-					 */
-					if (ltbnoa <= args->agbno - gtdiff) {
-						xfs_btree_del_cursor(
-							bno_cur_lt,
-							XFS_BTREE_NOERROR);
-						bno_cur_lt = NULL;
-						break;
-					}
-					/*
-					 * If we reach a big enough entry,
-					 * compare the two and pick the best.
-					 */
-					if (ltlena >= args->minlen) {
-						args->len = XFS_EXTLEN_MIN(
-							ltlena, args->maxlen);
-						xfs_alloc_fix_len(args);
-						rlen = args->len;
-						ltdiff = xfs_alloc_compute_diff(
-							args->agbno, rlen,
-							args->alignment,
-							ltbno, ltlen, &ltnew);
-						/*
-						 * Left side is better.
-						 */
-						if (ltdiff < gtdiff) {
-							xfs_btree_del_cursor(
-								bno_cur_gt,
-								XFS_BTREE_NOERROR);
-							bno_cur_gt = NULL;
-						}
-						/*
-						 * Right side is better.
-						 */
-						else {
-							xfs_btree_del_cursor(
-								bno_cur_lt,
-								XFS_BTREE_NOERROR);
-							bno_cur_lt = NULL;
-						}
-						break;
-					}
-					/*
-					 * Fell off the left end.
-					 */
-					if ((error = xfs_btree_decrement(
-							bno_cur_lt, 0, &i)))
-						goto error0;
-					if (!i) {
-						xfs_btree_del_cursor(bno_cur_lt,
-							XFS_BTREE_NOERROR);
-						bno_cur_lt = NULL;
-						break;
-					}
-				}
-			}
-			/*
-			 * The right side is perfect, trash the left side.
-			 */
-			else {
-				xfs_btree_del_cursor(bno_cur_lt,
-					XFS_BTREE_NOERROR);
-				bno_cur_lt = NULL;
-			}
+
+			error = xfs_alloc_find_best_extent(args,
+						&bno_cur_gt, &bno_cur_lt,
+						gtdiff, &ltbno, &ltlen, &ltlena,
+						1 /* search left */);
 		}
+
+		if (error)
+			goto error0;
 	}
+
 	/*
 	 * If we couldn't get anything, give up.
 	 */
@@ -1130,6 +1077,7 @@ xfs_alloc_ag_vextent_near(
 		args->agbno = NULLAGBLOCK;
 		return 0;
 	}
+
 	/*
 	 * At this point we have selected a freespace entry, either to the
 	 * left or to the right.  If it's on the right, copy all the
@@ -1146,6 +1094,7 @@ xfs_alloc_ag_vextent_near(
 		j = 1;
 	} else
 		j = 0;
+
 	/*
 	 * Fix up the length and compute the useful address.
 	 */
@@ -1248,8 +1197,7 @@ xfs_alloc_ag_vextent_size(
 	 * once aligned; if not, we search left for something better.
 	 * This can't happen in the second case above.
 	 */
-	xfs_alloc_compute_aligned(fbno, flen, args->alignment, args->minlen,
-		&rbno, &rlen);
+	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);
@@ -1274,8 +1222,8 @@ xfs_alloc_ag_vextent_size(
 			XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 			if (flen < bestrlen)
 				break;
-			xfs_alloc_compute_aligned(fbno, flen, args->alignment,
-				args->minlen, &rbno, &rlen);
+			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),
@@ -1453,6 +1401,7 @@ xfs_free_ag_extent(
 	xfs_mount_t	*mp;		/* mount point struct for filesystem */
 	xfs_agblock_t	nbno;		/* new starting block of freespace */
 	xfs_extlen_t	nlen;		/* new length of freespace */
+	xfs_perag_t	*pag;		/* per allocation group data */
 
 	mp = tp->t_mountp;
 	/*
@@ -1651,30 +1600,20 @@ xfs_free_ag_extent(
 	XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
 	xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
 	cnt_cur = NULL;
+
 	/*
 	 * Update the freespace totals in the ag and superblock.
 	 */
-	{
-		xfs_agf_t	*agf;
-		xfs_perag_t	*pag;		/* per allocation group data */
-
-		pag = xfs_perag_get(mp, agno);
-		pag->pagf_freeblks += len;
-		xfs_perag_put(pag);
-
-		agf = XFS_BUF_TO_AGF(agbp);
-		be32_add_cpu(&agf->agf_freeblks, len);
-		xfs_trans_agblocks_delta(tp, len);
-		XFS_WANT_CORRUPTED_GOTO(
-			be32_to_cpu(agf->agf_freeblks) <=
-			be32_to_cpu(agf->agf_length),
-			error0);
-		xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
-		if (!isfl)
-			xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
-		XFS_STATS_INC(xs_freex);
-		XFS_STATS_ADD(xs_freeb, len);
-	}
+	pag = xfs_perag_get(mp, agno);
+	error = xfs_alloc_update_counters(tp, pag, agbp, len);
+	xfs_perag_put(pag);
+	if (error)
+		goto error0;
+
+	if (!isfl)
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
+	XFS_STATS_INC(xs_freex);
+	XFS_STATS_ADD(xs_freeb, len);
 
 	trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
 
@@ -2456,17 +2395,33 @@ xfs_free_extent(
 	memset(&args, 0, sizeof(xfs_alloc_arg_t));
 	args.tp = tp;
 	args.mp = tp->t_mountp;
+
+	/*
+	 * validate that the block number is legal - the enables us to detect
+	 * and handle a silent filesystem corruption rather than crashing.
+	 */
 	args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
-	ASSERT(args.agno < args.mp->m_sb.sb_agcount);
+	if (args.agno >= args.mp->m_sb.sb_agcount)
+		return EFSCORRUPTED;
+
 	args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
+	if (args.agbno >= args.mp->m_sb.sb_agblocks)
+		return EFSCORRUPTED;
+
 	args.pag = xfs_perag_get(args.mp, args.agno);
-	if ((error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING)))
+	ASSERT(args.pag);
+
+	error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
+	if (error)
 		goto error0;
-#ifdef DEBUG
-	ASSERT(args.agbp != NULL);
-	ASSERT((args.agbno + len) <=
-		be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length));
-#endif
+
+	/* validate the extent size is legal now we have the agf locked */
+	if (args.agbno + len >
+			be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
+		error = EFSCORRUPTED;
+		goto error0;
+	}
+
 	error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
 error0:
 	xfs_perag_put(args.pag);
@@ -2676,7 +2631,7 @@ restart:
  * will require a synchronous transaction, but it can still be
  * used to distinguish between a partial or exact match.
  */
-static int
+int
 xfs_alloc_busy_search(
 	struct xfs_mount	*mp,
 	xfs_agnumber_t		agno,