[PATCH 5/7] ext4: factor out check for whether a cluster is allocated

[Zhang Yi <yi.zhang@xxxxxxxxxxxxxxx>]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

Factor out a common helper ext4_da_check_clu_allocated(), check whether
the cluster containing a delalloc block to be added has been delayed or
allocated, no logic changes.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
 fs/ext4/inode.c | 52 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 17 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 429fb99e937a..58bd4ed23cde 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1620,6 +1620,34 @@ static void ext4_print_free_blocks(struct inode *inode)
 	return;
 }
 
+/*
+ * Check whether the cluster containing lblk has been delayed or allocated,
+ * if not, it means we should reserve a cluster when add delalloc, return 1,
+ * otherwise return 0 or error code.
+ */
+static int ext4_da_check_clu_allocated(struct inode *inode, ext4_lblk_t lblk,
+				       bool *allocated)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	int ret;
+
+	*allocated = false;
+	if (ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk))
+		return 0;
+
+	if (ext4_es_scan_clu(inode, &ext4_es_is_mapped, lblk))
+		goto allocated;
+
+	ret = ext4_clu_mapped(inode, EXT4_B2C(sbi, lblk));
+	if (ret < 0)
+		return ret;
+	if (ret == 0)
+		return 1;
+allocated:
+	*allocated = true;
+	return 0;
+}
+
 /*
  * ext4_insert_delayed_block - adds a delayed block to the extents status
  *                             tree, incrementing the reserved cluster/block
@@ -1653,23 +1681,13 @@ static int ext4_insert_delayed_block(struct inode *inode, ext4_lblk_t lblk)
 		if (ret != 0)   /* ENOSPC */
 			return ret;
 	} else {   /* bigalloc */
-		if (!ext4_es_scan_clu(inode, &ext4_es_is_delonly, lblk)) {
-			if (!ext4_es_scan_clu(inode,
-					      &ext4_es_is_mapped, lblk)) {
-				ret = ext4_clu_mapped(inode,
-						      EXT4_B2C(sbi, lblk));
-				if (ret < 0)
-					return ret;
-				if (ret == 0) {
-					ret = ext4_da_reserve_space(inode, 1);
-					if (ret != 0)   /* ENOSPC */
-						return ret;
-				} else {
-					allocated = true;
-				}
-			} else {
-				allocated = true;
-			}
+		ret = ext4_da_check_clu_allocated(inode, lblk, &allocated);
+		if (ret < 0)
+			return ret;
+		if (ret > 0) {
+			ret = ext4_da_reserve_space(inode, 1);
+			if (ret != 0)   /* ENOSPC */
+				return ret;
 		}
 	}
 
-- 
2.39.2