jbd2: check superblock mapped prior to committing
We hit a BUG at fs/buffer.c:3057 if we detached the nbd device before unmounting ext4 filesystem. The typical chain of events leading to the BUG: jbd2_write_superblock submit_bh submit_bh_wbc BUG_ON(!buffer_mapped(bh)); The block device is removed and all the pages are invalidated. JBD2 was trying to write journal superblock to the block device which is no longer present. Fix this by checking the journal superblock's buffer head prior to submitting. Reported-by:Eric Ren <renzhen@linux.alibaba.com> Signed-off-by:
Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu> Reviewed-by:
Jan Kara <jack@suse.cz> Cc: stable@kernel.org
parent
fe53cbc5
Please register or sign in to comment