ext4: add ext4_sb_block_valid() refactored out of ext4_inode_block_valid()

This API will be needed at places where we don't have an inode
for e.g. while freeing blocks in ext4_group_add_blocks()
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/dd34a236543ad5ae7123eeebe0cb69e6bdd44f34.1644992610.git.riteshh@linux.ibm.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/block_validity.c

@@ -292,15 +292,10 @@ void ext4_release_system_zone(struct super_block *sb)
 		call_rcu(&system_blks->rcu, ext4_destroy_system_zone);
 }
 
-/*
- * Returns 1 if the passed-in block region (start_blk,
- * start_blk+count) is valid; 0 if some part of the block region
- * overlaps with some other filesystem metadata blocks.
- */
-int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
-			  unsigned int count)
+int ext4_sb_block_valid(struct super_block *sb, struct inode *inode,
+				ext4_fsblk_t start_blk, unsigned int count)
 {
-	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_system_blocks *system_blks;
 	struct ext4_system_zone *entry;
 	struct rb_node *n;
@@ -329,7 +324,9 @@ int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
 		else if (start_blk >= (entry->start_blk + entry->count))
 			n = n->rb_right;
 		else {
-			ret = (entry->ino == inode->i_ino);
+			ret = 0;
+			if (inode)
+				ret = (entry->ino == inode->i_ino);
 			break;
 		}
 	}
@@ -338,6 +335,17 @@ int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
 	return ret;
 }
 
+/*
+ * Returns 1 if the passed-in block region (start_blk,
+ * start_blk+count) is valid; 0 if some part of the block region
+ * overlaps with some other filesystem metadata blocks.
+ */
+int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
+			  unsigned int count)
+{
+	return ext4_sb_block_valid(inode->i_sb, inode, start_blk, count);
+}
+
 int ext4_check_blockref(const char *function, unsigned int line,
 			struct inode *inode, __le32 *p, unsigned int max)
 {

fs/ext4/ext4.h

@@ -3707,6 +3707,9 @@ extern int ext4_inode_block_valid(struct inode *inode,
 				  unsigned int count);
 extern int ext4_check_blockref(const char *, unsigned int,
 			       struct inode *, __le32 *, unsigned int);
+extern int ext4_sb_block_valid(struct super_block *sb, struct inode *inode,
+				ext4_fsblk_t start_blk, unsigned int count);
+
 
 /* extents.c */
 struct ext4_ext_path;