xfs: refactor inode ownership change transaction/inode/quota allocation idiom

For file ownership (uid, gid, prid) changes, create a new helper
xfs_trans_alloc_ichange that allocates a transaction and reserves the
appropriate amount of quota against that transction in preparation for a
change of user, group, or project id.  Replace all the open-coded idioms
with a single call to this helper so that we can contain the retry loops
in the next patchset.

This changes the locking behavior for ichange transactions slightly.
Since tr_ichange does not have a permanent reservation and cannot roll,
we pass XFS_ILOCK_EXCL to ijoin so that the inode will be unlocked
automatically at commit time.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

1 files changed, 2 insertions, 24 deletions

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f1e21b6cfa48..00369502fe25 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -700,13 +700,11 @@ xfs_setattr_nonsize(
 			return error;
 	}
 
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
+	error = xfs_trans_alloc_ichange(ip, udqp, gdqp, NULL,
+			capable(CAP_FOWNER), &tp);
 	if (error)
 		goto out_dqrele;
 
-	xfs_ilock(ip, XFS_ILOCK_EXCL);
-	xfs_trans_ijoin(tp, ip, 0);
-
 	/*
 	 * Change file ownership.  Must be the owner or privileged.
 	 */
@@ -723,21 +721,6 @@ xfs_setattr_nonsize(
 		uid = (mask & ATTR_UID) ? iattr->ia_uid : iuid;
 
 		/*
-		 * Do a quota reservation only if uid/gid is actually
-		 * going to change.
-		 */
-		if (XFS_IS_QUOTA_RUNNING(mp) &&
-		    ((XFS_IS_UQUOTA_ON(mp) && !uid_eq(iuid, uid)) ||
-		     (XFS_IS_GQUOTA_ON(mp) && !gid_eq(igid, gid)))) {
-			ASSERT(tp);
-			error = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp,
-						NULL, capable(CAP_FOWNER) ?
-						XFS_QMOPT_FORCE_RES : 0);
-			if (error)	/* out of quota */
-				goto out_cancel;
-		}
-
-		/*
 		 * CAP_FSETID overrides the following restrictions:
 		 *
 		 * The set-user-ID and set-group-ID bits of a file will be
@@ -786,8 +769,6 @@ xfs_setattr_nonsize(
 		xfs_trans_set_sync(tp);
 	error = xfs_trans_commit(tp);
 
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
 	/*
 	 * Release any dquot(s) the inode had kept before chown.
 	 */
@@ -814,9 +795,6 @@ xfs_setattr_nonsize(
 
 	return 0;
 
-out_cancel:
-	xfs_trans_cancel(tp);
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 out_dqrele:
 	xfs_qm_dqrele(udqp);
 	xfs_qm_dqrele(gdqp);