[PATCH 2/2] xfs: fix broken bhold behavior in xrep_roll_ag_trans

Darrick J. Wong
2019-04-25T05:52:20Z

From: Darrick J. Wong <darrick.wong@oracle.com>

In xrep_roll_ag_trans, the transaction roll will always set sc->tp to
the new transaction, even if committing the old one fails. A bare
transaction roll leaves the buffer(s) locked but not joined to the new
transaction, so it's not necessary to release the hold if the roll
fails. Remove the incorrect xfs_trans_bhold_release calls.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/scrub/repair.c | 25 ++++++++-----------------
1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 5e7e36cdf3d5..eb358f0f5e0a 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -136,10 +136,16 @@ xrep_roll_ag_trans(
if (sc->sa.agfl_bp)
xfs_trans_bhold(sc->tp, sc->sa.agfl_bp);

- /* Roll the transaction. */
+ /*
+ * Roll the transaction. We still own the buffer and the buffer lock
+ * regardless of whether or not the roll succeeds. If the roll fails,
+ * the buffers will be released during teardown on our way out of the
+ * kernel. If it succeeds, we join them to the new transaction and
+ * move on.
+ */
error = xfs_trans_roll(&sc->tp);
if (error)
- goto out_release;
+ return error;

/* Join AG headers to the new transaction. */
if (sc->sa.agi_bp)
@@ -150,21 +156,6 @@ xrep_roll_ag_trans(
xfs_trans_bjoin(sc->tp, sc->sa.agfl_bp);

return 0;
-
-out_release:
- /*
- * Rolling failed, so release the hold on the buffers. The
- * buffers will be released during teardown on our way out
- * of the kernel.
- */
- if (sc->sa.agi_bp)
- xfs_trans_bhold_release(sc->tp, sc->sa.agi_bp);
- if (sc->sa.agf_bp)
- xfs_trans_bhold_release(sc->tp, sc->sa.agf_bp);
- if (sc->sa.agfl_bp)
- xfs_trans_bhold_release(sc->tp, sc->sa.agfl_bp);
-
- return error;
}

/*