xfs: make COW fork unwritten extent conversions more robust
If we have racing buffered and direct I/O COW fork extents under
writeback can have been moved to the data fork by the time we call
xfs_reflink_convert_cow from xfs_submit_ioend. This would be mostly
harmless as the block numbers don't change by this move, except for
the fact that xfs_bmapi_write will crash or trigger asserts when
not finding existing extents, even despite trying to paper over this
with the XFS_BMAPI_CONVERT_ONLY flag.
Instead of special casing non-transaction conversions in the already
way too complicated xfs_bmapi_write just add a new helper for the much
simpler non-transactional COW fork case, which simplify ignores not
found extents.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index e4f29eb..48502cb 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -2031,7 +2031,7 @@ xfs_bmap_add_extent_delay_real(
/*
* Convert an unwritten allocation to a real allocation or vice versa.
*/
-STATIC int /* error */
+int /* error */
xfs_bmap_add_extent_unwritten_real(
struct xfs_trans *tp,
xfs_inode_t *ip, /* incore inode pointer */
@@ -4276,9 +4276,7 @@ xfs_bmapi_write(
ASSERT(*nmap >= 1);
ASSERT(*nmap <= XFS_BMAP_MAX_NMAP);
- ASSERT(tp != NULL ||
- (flags & (XFS_BMAPI_CONVERT | XFS_BMAPI_COWFORK)) ==
- (XFS_BMAPI_CONVERT | XFS_BMAPI_COWFORK));
+ ASSERT(tp != NULL);
ASSERT(len > 0);
ASSERT(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_LOCAL);
ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
@@ -4352,8 +4350,7 @@ xfs_bmapi_write(
* First, deal with the hole before the allocated space
* that we found, if any.
*/
- if ((need_alloc || wasdelay) &&
- !(flags & XFS_BMAPI_CONVERT_ONLY)) {
+ if (need_alloc || wasdelay) {
bma.eof = eof;
bma.conv = !!(flags & XFS_BMAPI_CONVERT);
bma.wasdel = wasdelay;
