ext4: fix incorrect punch max_end

[ Upstream commit 29ec9bed2395061350249ae356fb300dd82a78e7 ]

For the extents based inodes, the maxbytes should be sb->s_maxbytes
instead of sbi->s_bitmap_maxbytes. Additionally, for the calculation of
max_end, the -sb->s_blocksize operation is necessary only for
indirect-block based inodes. Correct the maxbytes and max_end value to
correct the behavior of punch hole.

Fixes: 2da3762 ("ext4: limit length to bitmap_maxbytes - blocksize in punch_hole")
Signed-off-by: Zhang Yi <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Reviewed-by: Baokun Li <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
Cc: [email protected]
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: zhangyi089

fs/ext4/inode.c

@@ -3992,7 +3992,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	struct inode *inode = file_inode(file);
 	struct super_block *sb = inode->i_sb;
 	ext4_lblk_t start_lblk, end_lblk;
-	loff_t max_end = EXT4_SB(sb)->s_bitmap_maxbytes - sb->s_blocksize;
+	loff_t max_end = sb->s_maxbytes;
 	loff_t end = offset + length;
 	handle_t *handle;
 	unsigned int credits;
@@ -4001,14 +4001,20 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	trace_ext4_punch_hole(inode, offset, length, 0);
 	WARN_ON_ONCE(!inode_is_locked(inode));
 
+	/*
+	 * For indirect-block based inodes, make sure that the hole within
+	 * one block before last range.
+	 */
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		max_end = EXT4_SB(sb)->s_bitmap_maxbytes - sb->s_blocksize;
+
 	/* No need to punch hole beyond i_size */
 	if (offset >= inode->i_size)
 		return 0;
 
 	/*
 	 * If the hole extends beyond i_size, set the hole to end after
-	 * the page that contains i_size, and also make sure that the hole
-	 * within one block before last range.
+	 * the page that contains i_size.
 	 */
 	if (end > inode->i_size)
 		end = round_up(inode->i_size, PAGE_SIZE);