[PATCH 6.1 15/23] xfs: Fix xfs_prepare_shift() range for RT

From: John Garry <[email protected]>

[ Upstream commit f23660f059470ec7043748da7641e84183c23bc8 ]

The RT extent range must be considered in the xfs_flush_unmap_range() call
to stabilize the boundary.

This code change is originally from Dave Chinner.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Darrick J. Wong <[email protected]>
Signed-off-by: John Garry <[email protected]>
Signed-off-by: Chandan Babu R <[email protected]>
Signed-off-by: Leah Rumancik <[email protected]>
Acked-by: "Darrick J. Wong" <[email protected]>
---
 fs/xfs/xfs_bmap_util.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index dabae6323c50..bab8ba224e10 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1057,33 +1057,35 @@ xfs_free_file_space(
 static int
 xfs_prepare_shift(
 	struct xfs_inode	*ip,
 	loff_t			offset)
 {
-	struct xfs_mount	*mp = ip->i_mount;
+	unsigned int		rounding;
 	int			error;
 
 	/*
 	 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
 	 * into the accessible region of the file.
 	 */
 	if (xfs_can_free_eofblocks(ip)) {
 		error = xfs_free_eofblocks(ip);
 		if (error)
 			return error;
 	}
 
 	/*
 	 * Shift operations must stabilize the start block offset boundary along
 	 * with the full range of the operation. If we don't, a COW writeback
 	 * completion could race with an insert, front merge with the start
 	 * extent (after split) during the shift and corrupt the file. Start
-	 * with the block just prior to the start to stabilize the boundary.
+	 * with the allocation unit just prior to the start to stabilize the
+	 * boundary.
 	 */
-	offset = round_down(offset, mp->m_sb.sb_blocksize);
+	rounding = xfs_inode_alloc_unitsize(ip);
+	offset = rounddown_64(offset, rounding);
 	if (offset)
-		offset -= mp->m_sb.sb_blocksize;
+		offset -= rounding;
 
 	/*
 	 * Writeback and invalidate cache for the remainder of the file as we're
 	 * about to shift down every extent from offset to EOF.
 	 */
-- 
2.50.0.rc1.591.g9c95f17f64-goog