ext4: BUG_ON assertion repeated for inode1, not done for inode2

During a source code review of fs/ext4/extents.c I noted identical consecutive lines. An assertion is repeated for inode1 and never done for inode2. This is not in keeping with the rest of the code in the ext4_swap_extents function and appears to be a bug.

Assert that the inode2 mutex is not locked.

Signed-off-by David Moore <[email protected]>

---
 fs/ext4/extents.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

fs/ext4/extents.c +1 -1

index e003a1e..f38a6d6 100644
@@ -5542,7 +5542,7 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
        BUG_ON(!mutex_is_locked(&inode1->i_mutex));
-       BUG_ON(!mutex_is_locked(&inode1->i_mutex));
+       BUG_ON(!mutex_is_locked(&inode2->i_mutex));
 
        *erp = ext4_es_remove_extent(inode1, lblk1, count);
        if (unlikely(*erp))

Signature · 4 lines

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Quoted 6 lines · David Moore

During a source code review of fs/ext4/extents.c I noted identical consecutive lines. An assertion is repeated for inode1 and never done for inode2. This is not in keeping with the rest of the code in the ext4_swap_extents function and appears to be a bug.

Assert that the inode2 mutex is not locked.

Yep, it's been that way since

fcf6b1b ext4: refactor ext4_move_extents code base

and it's pretty obviously not right as it is, and
if there's any doubt the comments make it clear:

+ * Locking:
+ * i_mutex is held for both inodes
+ * i_data_sem is locked for write for both inodes

Thanks,

Reviewed-by Eric Sandeen <[email protected]>