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authorChristoph Hellwig <hch@lst.de>2019-02-18 18:38:47 +0100
committerDarrick J. Wong <darrick.wong@oracle.com>2019-02-21 16:55:07 +0100
commit12df89f28fa92e54bfb2ae01f9ee059e74e1acc0 (patch)
tree0efda47845c91699855f6e83c1ef0f7e672483ac /fs/xfs/xfs_aops.c
parentxfs: don't use delalloc extents for COW on files with extsize hints (diff)
downloadlinux-12df89f28fa92e54bfb2ae01f9ee059e74e1acc0.tar.xz
linux-12df89f28fa92e54bfb2ae01f9ee059e74e1acc0.zip
xfs: also truncate holes covered by COW blocks
This only matters if we want to write data through the COW fork that is not actually an overwrite of existing data. Reasons for that are speculative COW fork allocations using the cowextsize, or a mode where we always write through the COW fork. Currently both can't actually happen, but I plan to enable them. 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>
Diffstat (limited to '')
-rw-r--r--fs/xfs/xfs_aops.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 2ed8733eca49..983d11c27d32 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -447,28 +447,29 @@ retry:
wpc->fork = XFS_DATA_FORK;
+ /* landed in a hole or beyond EOF? */
if (imap.br_startoff > offset_fsb) {
- /* landed in a hole or beyond EOF */
imap.br_blockcount = imap.br_startoff - offset_fsb;
imap.br_startoff = offset_fsb;
imap.br_startblock = HOLESTARTBLOCK;
imap.br_state = XFS_EXT_NORM;
- } else {
- /*
- * Truncate to the next COW extent if there is one. This is the
- * only opportunity to do this because we can skip COW fork
- * lookups for the subsequent blocks in the mapping; however,
- * the requirement to treat the COW range separately remains.
- */
- if (cow_fsb != NULLFILEOFF &&
- cow_fsb < imap.br_startoff + imap.br_blockcount)
- imap.br_blockcount = cow_fsb - imap.br_startoff;
-
- /* got a delalloc extent? */
- if (isnullstartblock(imap.br_startblock))
- goto allocate_blocks;
}
+ /*
+ * Truncate to the next COW extent if there is one. This is the only
+ * opportunity to do this because we can skip COW fork lookups for the
+ * subsequent blocks in the mapping; however, the requirement to treat
+ * the COW range separately remains.
+ */
+ if (cow_fsb != NULLFILEOFF &&
+ cow_fsb < imap.br_startoff + imap.br_blockcount)
+ imap.br_blockcount = cow_fsb - imap.br_startoff;
+
+ /* got a delalloc extent? */
+ if (imap.br_startblock != HOLESTARTBLOCK &&
+ isnullstartblock(imap.br_startblock))
+ goto allocate_blocks;
+
wpc->imap = imap;
trace_xfs_map_blocks_found(ip, offset, count, wpc->fork, &imap);
return 0;