On Fri, Jun 29, 2018 at 01:36:35PM -0600, Jon Derrick wrote: > This patch attempts to close a hole leading to a BUG seen with hot > removals during writes [1]. > > A block device (NVME namespace in this test case) is formatted to EXT4 > without partitions. It's mounted and write I/O is run to a file, then > the device is hot removed from the slot. The superblock attempts to be > written to the drive which is no longer present. > > The typical chain of events leading to the BUG: > ext4_commit_super() > __sync_dirty_buffer() > submit_bh() > submit_bh_wbc() > BUG_ON(!buffer_mapped(bh)); > > This fix checks for the superblock's buffer head being mapped prior to > syncing. > > [1] https://www.spinics.net/lists/linux-ext4/msg56527.html > > Signed-off-by: Jon Derrick <jonathan.derrick@xxxxxxxxx> Thanks, applied. - Ted
