From: Chandan Babu R <chandanrlinux@xxxxxxxxx>
Source kernel commit: 727e1acd297cae15449607d6e2ee39c71216cf1a
When adding a new data extent (without modifying an inode's existing
extents) the extent count increases only by 1. This commit checks for
extent count overflow in such cases.
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Allison Henderson <allison.henderson@xxxxxxxxxx>
---
libxfs/xfs_bmap.c | 6 ++++++
libxfs/xfs_inode_fork.h | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/libxfs/xfs_bmap.c b/libxfs/xfs_bmap.c
index 1e53cbd..336c6d6 100644
--- a/libxfs/xfs_bmap.c
+++ b/libxfs/xfs_bmap.c
@@ -4520,6 +4520,12 @@ xfs_bmapi_convert_delalloc(
return error;
xfs_ilock(ip, XFS_ILOCK_EXCL);
+
+ error = xfs_iext_count_may_overflow(ip, whichfork,
+ XFS_IEXT_ADD_NOSPLIT_CNT);
+ if (error)
+ goto out_trans_cancel;
+
xfs_trans_ijoin(tp, ip, 0);
if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &bma.icur, &bma.got) ||
diff --git a/libxfs/xfs_inode_fork.h b/libxfs/xfs_inode_fork.h
index 0beb8e2..7fc2b12 100644
--- a/libxfs/xfs_inode_fork.h
+++ b/libxfs/xfs_inode_fork.h
@@ -35,6 +35,12 @@ struct xfs_ifork {
#define XFS_IFBROOT 0x04 /* i_broot points to the bmap b-tree root */
/*
+ * Worst-case increase in the fork extent count when we're adding a single
+ * extent to a fork and there's no possibility of splitting an existing mapping.
+ */
+#define XFS_IEXT_ADD_NOSPLIT_CNT (1)
+
+/*
* Fork handling.
*/
--
2.7.4
