summaryrefslogtreecommitdiff
path: root/fs/xfs/libxfs
diff options
context:
space:
mode:
authorChandan Babu R <chandanrlinux@gmail.com>2021-01-22 16:48:14 -0800
committerDarrick J. Wong <djwong@kernel.org>2021-01-22 16:54:48 -0800
commitc442f3086d5a108b7ff086c8ade1923a8f389db5 (patch)
tree25464ffb363d5d2d092acb124d61feb885c6c8c7 /fs/xfs/libxfs
parent3a19bb147c72d2e9b77137bf5130b9cfb50a5eef (diff)
xfs: Check for extent overflow when writing to unwritten extent
A write to a sub-interval of an existing unwritten extent causes the original extent to be split into 3 extents i.e. | Unwritten | Real | Unwritten | Hence extent count can increase by 2. Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r--fs/xfs/libxfs/xfs_inode_fork.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index 8d89838e23f8..917e289ad962 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -71,6 +71,15 @@ struct xfs_ifork {
(XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))
/*
+ * A write to a sub-interval of an existing unwritten extent causes the original
+ * extent to be split into 3 extents
+ * i.e. | Unwritten | Real | Unwritten |
+ * Hence extent count can increase by 2.
+ */
+#define XFS_IEXT_WRITE_UNWRITTEN_CNT (2)
+
+
+/*
* Fork handling.
*/