1 files changed, 23 insertions, 17 deletions

diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index c41190c..6cdf6ff 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -489,31 +489,36 @@ xfs_qm_scall_setqlim(
 	if ((newlim->d_fieldmask & XFS_DQ_MASK) == 0)
 		return 0;
 
-	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SETQLIM);
-	error = xfs_trans_reserve(tp, 0, XFS_QM_SETQLIM_LOG_RES(mp),
-				  0, 0, XFS_DEFAULT_LOG_COUNT);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		return (error);
-	}
-
 	/*
 	 * We don't want to race with a quotaoff so take the quotaoff lock.
-	 * (We don't hold an inode lock, so there's nothing else to stop
-	 * a quotaoff from happening). (XXXThis doesn't currently happen
-	 * because we take the vfslock before calling xfs_qm_sysent).
+	 * We don't hold an inode lock, so there's nothing else to stop
+	 * a quotaoff from happening.
 	 */
 	mutex_lock(&q->qi_quotaofflock);
 
 	/*
-	 * Get the dquot (locked), and join it to the transaction.
-	 * Allocate the dquot if this doesn't exist.
+	 * Get the dquot (locked) before we start, as we need to do a
+	 * transaction to allocate it if it doesn't exist. Once we have the
+	 * dquot, unlock it so we can start the next transaction safely. We hold
+	 * a reference to the dquot, so it's safe to do this unlock/lock without
+	 * it being reclaimed in the mean time.
 	 */
-	if ((error = xfs_qm_dqget(mp, NULL, id, type, XFS_QMOPT_DQALLOC, &dqp))) {
-		xfs_trans_cancel(tp, XFS_TRANS_ABORT);
+	error = xfs_qm_dqget(mp, NULL, id, type, XFS_QMOPT_DQALLOC, &dqp);
+	if (error) {
 		ASSERT(error != ENOENT);
 		goto out_unlock;
 	}
+	xfs_dqunlock(dqp);
+
+	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SETQLIM);
+	error = xfs_trans_reserve(tp, 0, XFS_QM_SETQLIM_LOG_RES(mp),
+				  0, 0, XFS_DEFAULT_LOG_COUNT);
+	if (error) {
+		xfs_trans_cancel(tp, 0);
+		goto out_rele;
+	}
+
+	xfs_dqlock(dqp);
 	xfs_trans_dqjoin(tp, dqp);
 	ddq = &dqp->q_core;
 
@@ -621,9 +626,10 @@ xfs_qm_scall_setqlim(
 	xfs_trans_log_dquot(tp, dqp);
 
 	error = xfs_trans_commit(tp, 0);
-	xfs_qm_dqrele(dqp);
 
- out_unlock:
+out_rele:
+	xfs_qm_dqrele(dqp);
+out_unlock:
 	mutex_unlock(&q->qi_quotaofflock);
 	return error;
 }