From 5147ef30f2cd128c9eedf7a697e8cb2ce2767989 Mon Sep 17 00:00:00 2001 From: Chandan Babu R Date: Thu, 25 Mar 2021 11:48:18 -0700 Subject: [PATCH] xfs: Fix dax inode extent calculation when direct write is performed on an unwritten extent 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 Signed-off-by: Chandan Babu R Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- 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 e17ab7f42928a..8b27c10a3d085 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; -- 2.30.2