xfs: create convenience wrappers for incore quota block reservations

Create a couple of convenience wrappers for creating and deleting quota
block reservations against future changes.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>

fs/xfs/libxfs/xfs_bmap.c

@@ -4097,8 +4097,7 @@ xfs_bmapi_reserve_delalloc(
 	 * blocks.  This number gets adjusted later.  We return if we haven't
 	 * allocated blocks already inside this loop.
 	 */
-	error = xfs_trans_reserve_quota_nblks(NULL, ip, (long)alen, 0,
-						XFS_QMOPT_RES_REGBLKS);
+	error = xfs_quota_reserve_blkres(ip, alen);
 	if (error)
 		return error;
 
@@ -4144,8 +4143,7 @@ xfs_bmapi_reserve_delalloc(
 	xfs_mod_fdblocks(mp, alen, false);
 out_unreserve_quota:
 	if (XFS_IS_QUOTA_ON(mp))
-		xfs_trans_unreserve_quota_nblks(NULL, ip, (long)alen, 0,
-						XFS_QMOPT_RES_REGBLKS);
+		xfs_quota_unreserve_blkres(ip, alen);
 	return error;
 }
 
@@ -4937,8 +4935,8 @@ xfs_bmap_del_extent_delay(
 	 * sb counters as we might have to borrow some blocks for the
 	 * indirect block accounting.
 	 */
-	error = xfs_trans_unreserve_quota_nblks(NULL, ip, del->br_blockcount, 0,
-			isrt ? XFS_QMOPT_RES_RTBLKS : XFS_QMOPT_RES_REGBLKS);
+	ASSERT(!isrt);
+	error = xfs_quota_unreserve_blkres(ip, del->br_blockcount);
 	if (error)
 		return error;
 	ip->i_delayed_blks -= del->br_blockcount;

fs/xfs/xfs_quota.h

@@ -108,6 +108,12 @@ extern void xfs_qm_mount_quotas(struct xfs_mount *);
 extern void xfs_qm_unmount(struct xfs_mount *);
 extern void xfs_qm_unmount_quotas(struct xfs_mount *);
 
+static inline int
+xfs_quota_reserve_blkres(struct xfs_inode *ip, int64_t blocks)
+{
+	return xfs_trans_reserve_quota_nblks(NULL, ip, blocks, 0,
+			XFS_QMOPT_RES_REGBLKS);
+}
 #else
 static inline int
 xfs_qm_vop_dqalloc(struct xfs_inode *ip, kuid_t kuid, kgid_t kgid,
@@ -136,6 +142,13 @@ static inline int xfs_trans_reserve_quota_bydquots(struct xfs_trans *tp,
 {
 	return 0;
 }
+
+static inline int
+xfs_quota_reserve_blkres(struct xfs_inode *ip, int64_t blocks)
+{
+	return 0;
+}
+
 #define xfs_qm_vop_create_dqattach(tp, ip, u, g, p)
 #define xfs_qm_vop_rename_dqattach(it)					(0)
 #define xfs_qm_vop_chown(tp, ip, old, new)				(NULL)
@@ -157,6 +170,12 @@ static inline int xfs_trans_reserve_quota_bydquots(struct xfs_trans *tp,
 	xfs_trans_reserve_quota_bydquots(tp, mp, ud, gd, pd, nb, ni, \
 				f | XFS_QMOPT_RES_REGBLKS)
 
+static inline int
+xfs_quota_unreserve_blkres(struct xfs_inode *ip, int64_t blocks)
+{
+	return xfs_quota_reserve_blkres(ip, -blocks);
+}
+
 extern int xfs_mount_reset_sbqflags(struct xfs_mount *);
 
 #endif	/* __XFS_QUOTA_H__ */

fs/xfs/xfs_reflink.c

@@ -508,9 +508,8 @@ xfs_reflink_cancel_cow_blocks(
 			xfs_bmap_del_extent_cow(ip, &icur, &got, &del);
 
 			/* Remove the quota reservation */
-			error = xfs_trans_unreserve_quota_nblks(NULL, ip,
-					del.br_blockcount, 0,
-					XFS_QMOPT_RES_REGBLKS);
+			error = xfs_quota_unreserve_blkres(ip,
+					del.br_blockcount);
 			if (error)
 				break;
 		} else {