From: Chandan Babu R <chandanrlinux@gmail.com> mainline inclusion from mainline-v5.12-rc1 commit 5147ef30f2cd128c9eedf7a697e8cb2ce2767989 category: bugfix bugzilla: 187510,https://gitee.com/openeuler/kernel/issues/I4KIAO Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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@kernel.org> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Guo Xuenan <guoxuenan@huawei.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- 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 cf22dad509e1..31c553a49241 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; -- 2.20.1