[PATCH 41/43] xfs: check for shared rt extents when rebuilding rt file's data fork

Darrick J. Wong
2024-12-19T19:43:43Z

From: Darrick J. Wong <djwong@kernel.org>

When we're rebuilding the data fork of a realtime file, we need to
cross-reference each mapping with the rt refcount btree to ensure that
the reflink flag is set if there are any shared extents found.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/scrub/bmap_repair.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/scrub/bmap_repair.c b/fs/xfs/scrub/bmap_repair.c
index fd64bdf4e13887..1084213b8e9b88 100644
--- a/fs/xfs/scrub/bmap_repair.c
+++ b/fs/xfs/scrub/bmap_repair.c
@@ -101,14 +101,21 @@ xrep_bmap_discover_shared(
xfs_filblks_t blockcount)
{
struct xfs_scrub *sc = rb->sc;
+ struct xfs_btree_cur *cur;
xfs_agblock_t agbno;
xfs_agblock_t fbno;
xfs_extlen_t flen;
int error;

- agbno = XFS_FSB_TO_AGBNO(sc->mp, startblock);
- error = xfs_refcount_find_shared(sc->sa.refc_cur, agbno, blockcount,
- &fbno, &flen, false);
+ if (XFS_IS_REALTIME_INODE(sc->ip)) {
+ agbno = xfs_rtb_to_rgbno(sc->mp, startblock);
+ cur = sc->sr.refc_cur;
+ } else {
+ agbno = XFS_FSB_TO_AGBNO(sc->mp, startblock);
+ cur = sc->sa.refc_cur;
+ }
+ error = xfs_refcount_find_shared(cur, agbno, blockcount, &fbno, &flen,
+ false);
if (error)
return error;

@@ -450,7 +457,9 @@ xrep_bmap_scan_rtgroup(
return 0;

error = xrep_rtgroup_init(sc, rtg, &sc->sr,
- XFS_RTGLOCK_RMAP | XFS_RTGLOCK_BITMAP_SHARED);
+ XFS_RTGLOCK_RMAP |
+ XFS_RTGLOCK_REFCOUNT |
+ XFS_RTGLOCK_BITMAP_SHARED);
if (error)
return error;

@@ -903,10 +912,6 @@ xrep_bmap_init_reflink_scan(
if (whichfork != XFS_DATA_FORK)
return RLS_IRRELEVANT;

- /* cannot share realtime extents */
- if (XFS_IS_REALTIME_INODE(sc->ip))
- return RLS_IRRELEVANT;
-
return RLS_UNKNOWN;
}