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@xxxxxxxxxx> Signed-off-by: Chandan Babu R <chandanrlinux@xxxxxxxxx> --- fs/xfs/libxfs/xfs_inode_fork.h | 8 ++++++++ fs/xfs/xfs_iomap.c | 5 +++++ 2 files changed, 13 insertions(+) diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index fd93fdc67ee4..afb647e1e3fa 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -70,6 +70,14 @@ struct xfs_ifork { #define XFS_IEXT_DIR_MANIP_CNT(mp) \ ((XFS_DA_NODE_MAXDEPTH + 1 + 1) * (mp)->m_dir_geo->fsbcount) +/* + * 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. */ diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index a302a96823b8..2aa788379611 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -566,6 +566,11 @@ xfs_iomap_write_unwritten( if (error) goto error_on_bmapi_transaction; + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_WRITE_UNWRITTEN_CNT); + if (error) + goto error_on_bmapi_transaction; + /* * Modify the unwritten extent state of the buffer. */ -- 2.28.0