6.6-stable review patch. If anyone has any objections, please let me know.
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From: Darrick J. Wong djwong@kernel.org
commit 44d9b07e52db25035680713c3428016cadcd2ea1 upstream.
Committing a transaction tx0 with a defer ops chain of (A, B, C) creates a chain of transactions that looks like this:
tx0 -> txA -> txB -> txC
Prior to commit cb042117488dbf, __xfs_trans_commit would run precommits on tx0, then call xfs_defer_finish_noroll to convert A-C to tx[A-C]. Unfortunately, after the finish_noroll loop we forgot to run precommits on txC. That was fixed by adding the second precommit call.
Unfortunately, none of us remembered that xfs_defer_finish_noroll calls __xfs_trans_commit a second time to commit tx0 before finishing work A in txA and committing that. In other words, we run precommits twice on tx0:
xfs_trans_commit(tx0) __xfs_trans_commit(tx0, false) xfs_trans_run_precommits(tx0) xfs_defer_finish_noroll(tx0) xfs_trans_roll(tx0) txA = xfs_trans_dup(tx0) __xfs_trans_commit(tx0, true) xfs_trans_run_precommits(tx0)
This currently isn't an issue because the inode item precommit is idempotent; the iunlink item precommit deletes itself so it can't be called again; and the buffer/dquot item precommits only check the incore objects for corruption. However, it doesn't make sense to run precommits twice.
Fix this situation by only running precommits after finish_noroll.
Cc: stable@vger.kernel.org # v6.4 Fixes: cb042117488dbf ("xfs: defered work could create precommits") Signed-off-by: "Darrick J. Wong" djwong@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/xfs/xfs_trans.c | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-)
--- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -955,13 +955,6 @@ __xfs_trans_commit(
trace_xfs_trans_commit(tp, _RET_IP_);
- error = xfs_trans_run_precommits(tp); - if (error) { - if (tp->t_flags & XFS_TRANS_PERM_LOG_RES) - xfs_defer_cancel(tp); - goto out_unreserve; - } - /* * Finish deferred items on final commit. Only permanent transactions * should ever have deferred ops. @@ -972,13 +965,12 @@ __xfs_trans_commit( error = xfs_defer_finish_noroll(&tp); if (error) goto out_unreserve; - - /* Run precommits from final tx in defer chain. */ - error = xfs_trans_run_precommits(tp); - if (error) - goto out_unreserve; }
+ error = xfs_trans_run_precommits(tp); + if (error) + goto out_unreserve; + /* * If there is nothing to be logged by the transaction, * then unlock all of the items associated with the