xfs: simplify iext overflow checking and upgrade

Currently the calls to xfs_iext_count_may_overflow and
xfs_iext_count_upgrade are always paired.  Merge them into a single
function to simplify the callers and the actual check and upgrade
logic itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

4 files changed, 29 insertions, 44 deletions

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index eb274d4d636d..430cd3244c14 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -1050,11 +1050,8 @@ xfs_attr_set(
 		return error;
 
 	if (op != XFS_ATTRUPDATE_REMOVE || xfs_inode_hasattr(dp)) {
-		error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
+		error = xfs_iext_count_extend(args->trans, dp, XFS_ATTR_FORK,
 				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
-		if (error == -EFBIG)
-			error = xfs_iext_count_upgrade(args->trans, dp,
-					XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
 		if (error)
 			goto out_trans_cancel;
 	}
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 0633f285875d..3b3206d312d6 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4651,11 +4651,8 @@ xfs_bmapi_convert_one_delalloc(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	error = xfs_iext_count_may_overflow(ip, whichfork,
+	error = xfs_iext_count_extend(tp, ip, whichfork,
 			XFS_IEXT_ADD_NOSPLIT_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip,
-				XFS_IEXT_ADD_NOSPLIT_CNT);
 	if (error)
 		goto out_trans_cancel;
 
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 7d660a973909..9d11ae015909 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -765,53 +765,46 @@ xfs_ifork_verify_local_attr(
 	return 0;
 }
 
+/*
+ * Check if the inode fork supports adding nr_to_add more extents.
+ *
+ * If it doesn't but we can upgrade it to large extent counters, do the upgrade.
+ * If we can't upgrade or are already using big counters but still can't fit the
+ * additional extents, return -EFBIG.
+ */
 int
-xfs_iext_count_may_overflow(
+xfs_iext_count_extend(
+	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	int			whichfork,
-	int			nr_to_add)
+	uint			nr_to_add)
 {
+	struct xfs_mount	*mp = ip->i_mount;
+	bool			has_large =
+		xfs_inode_has_large_extent_counts(ip);
 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
-	uint64_t		max_exts;
 	uint64_t		nr_exts;
 
+	ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);
+
 	if (whichfork == XFS_COW_FORK)
 		return 0;
 
-	max_exts = xfs_iext_max_nextents(xfs_inode_has_large_extent_counts(ip),
-				whichfork);
-
-	if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
-		max_exts = 10;
-
+	/* no point in upgrading if if_nextents overflows */
 	nr_exts = ifp->if_nextents + nr_to_add;
-	if (nr_exts < ifp->if_nextents || nr_exts > max_exts)
+	if (nr_exts < ifp->if_nextents)
 		return -EFBIG;
 
-	return 0;
-}
-
-/*
- * Upgrade this inode's extent counter fields to be able to handle a potential
- * increase in the extent count by nr_to_add.  Normally this is the same
- * quantity that caused xfs_iext_count_may_overflow() to return -EFBIG.
- */
-int
-xfs_iext_count_upgrade(
-	struct xfs_trans	*tp,
-	struct xfs_inode	*ip,
-	uint			nr_to_add)
-{
-	ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);
-
-	if (!xfs_has_large_extent_counts(ip->i_mount) ||
-	    xfs_inode_has_large_extent_counts(ip) ||
-	    XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
+	if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_REDUCE_MAX_IEXTENTS) &&
+	    nr_exts > 10)
 		return -EFBIG;
 
-	ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
-	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-
+	if (nr_exts > xfs_iext_max_nextents(has_large, whichfork)) {
+		if (has_large || !xfs_has_large_extent_counts(mp))
+			return -EFBIG;
+		ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
+		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+	}
 	return 0;
 }
 
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index bd53eb951b65..2373d12fd474 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -256,10 +256,8 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip);
 
 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
-int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
-		int nr_to_add);
-int xfs_iext_count_upgrade(struct xfs_trans *tp, struct xfs_inode *ip,
-		uint nr_to_add);
+int xfs_iext_count_extend(struct xfs_trans *tp, struct xfs_inode *ip,
+		int whichfork, uint nr_to_add);
 bool xfs_ifork_is_realtime(struct xfs_inode *ip, int whichfork);
 
 /* returns true if the fork has extents but they are not read in yet. */