With dax enabled filesystems, a direct write operation into an existing
unwritten extent results in xfs_iomap_write_direct() zero-ing and converting
the extent into a normal extent before the actual data is copied from the
userspace buffer.
The inode extent count can increase by 2 if the extent range being written to
maps to the middle of the existing unwritten extent range. Hence this commit
uses XFS_IEXT_WRITE_UNWRITTEN_CNT as the extent count delta when such a write
operation is being performed.
Fixes: 727e1acd297c ("xfs: Check for extent overflow when trivally adding a new extent")
Reported-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
---
fs/xfs/xfs_iomap.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index e17ab7f42928..8b27c10a3d08 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -198,6 +198,7 @@ xfs_iomap_write_direct(
bool force = false;
int error;
int bmapi_flags = XFS_BMAPI_PREALLOC;
+ int nr_exts = XFS_IEXT_ADD_NOSPLIT_CNT;
ASSERT(count_fsb > 0);
@@ -232,6 +233,7 @@ xfs_iomap_write_direct(
bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO;
if (imap->br_state == XFS_EXT_UNWRITTEN) {
force = true;
+ nr_exts = XFS_IEXT_WRITE_UNWRITTEN_CNT;
dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1;
}
}
@@ -241,8 +243,7 @@ xfs_iomap_write_direct(
if (error)
return error;
- error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
- XFS_IEXT_ADD_NOSPLIT_CNT);
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, nr_exts);
if (error)
goto out_trans_cancel;
--
2.29.2
