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authorLachlan McIlroy <lachlan@sgi.com>2008-06-27 13:32:53 +1000
committerNiv Sardi <xaiki@debian.org>2008-07-28 16:59:10 +1000
commit4ddd8bb1d25f9cbb345e1f64a56c0f641a787ede (patch)
tree297e8fa754cbd910450ff76a9058a2ac6cd07b39 /fs/xfs
parente182f57ac019b034b40d16f3c6d8e86826aecd56 (diff)
[XFS] use minleft when allocating in xfs_bmbt_split()
The bmap btree split code relies on a previous data extent allocation (from xfs_bmap_btalloc()) to find an AG that has sufficient space to perform a full btree split, when inserting the extent. When converting unwritten extents we don't allocate a data extent so a btree split will be the first allocation. In this case we need to set minleft so the allocator will pick an AG that has space to complete the split(s). SGI-PV: 983338 SGI-Modid: xfs-linux-melb:xfs-kern:31357a Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: David Chinner <dgc@sgi.com>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/xfs_bmap_btree.c15
-rw-r--r--fs/xfs/xfs_iomap.c10
2 files changed, 24 insertions, 1 deletions
diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 4aa2f11ba563..3fc09cd8d517 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -1493,12 +1493,25 @@ xfs_bmbt_split(
left = XFS_BUF_TO_BMBT_BLOCK(lbp);
args.fsbno = cur->bc_private.b.firstblock;
args.firstblock = args.fsbno;
+ args.minleft = 0;
if (args.fsbno == NULLFSBLOCK) {
args.fsbno = lbno;
args.type = XFS_ALLOCTYPE_START_BNO;
+ /*
+ * Make sure there is sufficient room left in the AG to
+ * complete a full tree split for an extent insert. If
+ * we are converting the middle part of an extent then
+ * we may need space for two tree splits.
+ *
+ * We are relying on the caller to make the correct block
+ * reservation for this operation to succeed. If the
+ * reservation amount is insufficient then we may fail a
+ * block allocation here and corrupt the filesystem.
+ */
+ args.minleft = xfs_trans_get_block_res(args.tp);
} else
args.type = XFS_ALLOCTYPE_NEAR_BNO;
- args.mod = args.minleft = args.alignment = args.total = args.isfl =
+ args.mod = args.alignment = args.total = args.isfl =
args.userdata = args.minalignslop = 0;
args.minlen = args.maxlen = args.prod = 1;
args.wasdel = cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL;
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 7edcde691d1a..67f22b2b44b3 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -889,6 +889,16 @@ xfs_iomap_write_unwritten(
count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb);
+ /*
+ * Reserve enough blocks in this transaction for two complete extent
+ * btree splits. We may be converting the middle part of an unwritten
+ * extent and in this case we will insert two new extents in the btree
+ * each of which could cause a full split.
+ *
+ * This reservation amount will be used in the first call to
+ * xfs_bmbt_split() to select an AG with enough space to satisfy the
+ * rest of the operation.
+ */
resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
do {