Hello,
My static analysis tool reports a possible ABBA deadlock in the ext4
module in Linux 5.10:
ext4_inline_data_truncate()
down_write(&EXT4_I(inode)->i_data_sem); --> Line 1895 (Lock A)
ext4_xattr_ibody_get()
ext4_xattr_inode_get()
ext4_xattr_inode_iget()
inode_lock(inode); --> Line 427 (Lock B)
ext4_punch_hole()
inode_lock(inode); --> Line 4018 (Lock B)
ext4_update_disksize_before_punch()
ext4_update_i_disksize()
down_write(&EXT4_I(inode)->i_data_sem); --> Line 3248 (Lock A)
When ext4_inline_data_truncate() and ext4_punch_hole() are concurrently
executed, the deadlock can occur.
I am not quite sure whether this possible deadlock is real and how to
fix it if it is real.
Any feedback would be appreciated, thanks :)
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Best wishes,
Jia-Ju Bai
