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authorBrian Foster <bfoster@redhat.com>2020-03-16 14:26:09 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2020-03-18 08:12:23 -0700
commit8a62714313391b9b2297d67c341b35edbf46c279 (patch)
tree17f0605090cedfe4ec9ad3964216048ded50e6ee /fs/xfs/xfs_qm_syscalls.c
parent854f82b1f6039a418b7d1407513f8640e05fd73f (diff)
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xfs: fix unmount hang and memory leak on shutdown during quotaoff
AIL removal of the quotaoff start intent and free of both quotaoff intents is currently limited to the ->iop_committed() handler of the end intent. This executes when the end intent is committed to the on-disk log and marks the completion of the operation. The problem with this is it assumes the success of the operation. If a shutdown or other error occurs during the quotaoff, it's possible for the quotaoff task to exit without removing the start intent from the AIL. This results in an unmount hang as the AIL cannot be emptied. Further, no other codepath frees the intents and so this is also a memory leak vector. First, update the high level quotaoff error path to directly remove and free the quotaoff start intent if it still exists in the AIL at the time of the error. Next, update both of the start and end quotaoff intents with an ->iop_release() callback to properly handle transaction abort. This means that If the quotaoff start transaction aborts, it frees the start intent in the transaction commit path. If the filesystem shuts down before the end transaction allocates, the quotaoff sequence removes and frees the start intent. If the end transaction aborts, it removes the start intent and frees both. This ensures that a shutdown does not result in a hung unmount and that memory is not leaked regardless of when a quotaoff error occurs. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/xfs/xfs_qm_syscalls.c')
-rw-r--r--fs/xfs/xfs_qm_syscalls.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 1ea82764bf89..5d5ac65aa1cc 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -29,8 +29,6 @@ xfs_qm_log_quotaoff(
int error;
struct xfs_qoff_logitem *qoffi;
- *qoffstartp = NULL;
-
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_qm_quotaoff, 0, 0, 0, &tp);
if (error)
goto out;
@@ -62,7 +60,7 @@ out:
STATIC int
xfs_qm_log_quotaoff_end(
struct xfs_mount *mp,
- struct xfs_qoff_logitem *startqoff,
+ struct xfs_qoff_logitem **startqoff,
uint flags)
{
struct xfs_trans *tp;
@@ -73,9 +71,10 @@ xfs_qm_log_quotaoff_end(
if (error)
return error;
- qoffi = xfs_trans_get_qoff_item(tp, startqoff,
+ qoffi = xfs_trans_get_qoff_item(tp, *startqoff,
flags & XFS_ALL_QUOTA_ACCT);
xfs_trans_log_quotaoff_item(tp, qoffi);
+ *startqoff = NULL;
/*
* We have to make sure that the transaction is secure on disk before we
@@ -103,7 +102,7 @@ xfs_qm_scall_quotaoff(
uint dqtype;
int error;
uint inactivate_flags;
- struct xfs_qoff_logitem *qoffstart;
+ struct xfs_qoff_logitem *qoffstart = NULL;
/*
* No file system can have quotas enabled on disk but not in core.
@@ -228,7 +227,7 @@ xfs_qm_scall_quotaoff(
* So, we have QUOTAOFF start and end logitems; the start
* logitem won't get overwritten until the end logitem appears...
*/
- error = xfs_qm_log_quotaoff_end(mp, qoffstart, flags);
+ error = xfs_qm_log_quotaoff_end(mp, &qoffstart, flags);
if (error) {
/* We're screwed now. Shutdown is the only option. */
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
@@ -261,6 +260,8 @@ xfs_qm_scall_quotaoff(
}
out_unlock:
+ if (error && qoffstart)
+ xfs_qm_qoff_logitem_relse(qoffstart);
mutex_unlock(&q->qi_quotaofflock);
return error;
}