linux-ext4 - [PATCH] ext4: Avoid BUG

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Date:   Mon, 21 Nov 2022 14:09:29 +0100
From:   Jan Kara <jack@...e.cz>
To:     Ted Tso <tytso@....edu>
Cc:     <linux-ext4@...r.kernel.org>, Jan Kara <jack@...e.cz>,
        Eric Sandeen <sandeen@...hat.com>
Subject: [PATCH] ext4: Avoid BUG_ON when creating xattrs

Commit fb0a387dcdcd ("ext4: limit block allocations for indirect-block
files to < 2^32") added code to try to allocate xattr block with 32-bit
block number for indirect block based files on the grounds that these
files cannot use larger block numbers. It also added BUG_ON when
allocated block could not fit into 32 bits. This is however bogus
reasoning because xattr block is stored in inode->i_file_acl and
inode->i_file_acl_hi and as such even indirect block based files can
happily use full 48 bits for xattr block number. The proper handling
seems to be there basically since 64-bit block number support was added.
So remove the bogus limitation and BUG_ON.

CC: Eric Sandeen <sandeen@...hat.com>
Fixes: fb0a387dcdcd ("ext4: limit block allocations for indirect-block files to < 2^32")
Signed-off-by: Jan Kara <jack@...e.cz>
---
 fs/ext4/xattr.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 36d6ba7190b6..800ce5cdb9d2 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2070,19 +2070,11 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,

 			goal = ext4_group_first_block_no(sb,
 						EXT4_I(inode)->i_block_group);
-
-			/* non-extent files can't have physical blocks past 2^32 */
-			if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-				goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
-
 			block = ext4_new_meta_blocks(handle, inode, goal, 0,
 						     NULL, &error);
 			if (error)
 				goto cleanup;

-			if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
-				BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
-
 			ea_idebug(inode, "creating block %llu",
 				  (unsigned long long)block);

-- 
2.35.3