Message ID | 20190805040800.31743-1-chandan@linux.ibm.com |
---|---|
State | Accepted, archived |
Headers | show |
Series | [V2] jbd2: flush_descriptor(): Do not decrease buffer head's ref count | expand |
On Mon, Aug 05, 2019 at 09:38:00AM +0530, Chandan Rajendra wrote: > When executing generic/388 on a ppc64le machine, we notice the following > call trace, > > VFS: brelse: Trying to free free buffer > WARNING: CPU: 0 PID: 6637 at /root/repos/linux/fs/buffer.c:1195 __brelse+0x84/0xc0 > > Call Trace: > __brelse+0x80/0xc0 (unreliable) > invalidate_bh_lru+0x78/0xc0 > on_each_cpu_mask+0xa8/0x130 > on_each_cpu_cond_mask+0x130/0x170 > invalidate_bh_lrus+0x44/0x60 > invalidate_bdev+0x38/0x70 > ext4_put_super+0x294/0x560 > generic_shutdown_super+0xb0/0x170 > kill_block_super+0x38/0xb0 > deactivate_locked_super+0xa4/0xf0 > cleanup_mnt+0x164/0x1d0 > task_work_run+0x110/0x160 > do_notify_resume+0x414/0x460 > ret_from_except_lite+0x70/0x74 > > The warning happens because flush_descriptor() drops bh reference it > does not own. The bh reference acquired by > jbd2_journal_get_descriptor_buffer() is owned by the log_bufs list and > gets released when this list is processed. The reference for doing IO is > only acquired in write_dirty_buffer() later in flush_descriptor(). > > Reported-by: Harish Sriram <harish@linux.ibm.com> > Reviewed-by: Jan Kara <jack@suse.cz> > Signed-off-by: Chandan Rajendra <chandan@linux.ibm.com> Thanks, applied. - Ted
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c index 69b9bc329964..f08073d7bbf5 100644 --- a/fs/jbd2/revoke.c +++ b/fs/jbd2/revoke.c @@ -638,10 +638,8 @@ static void flush_descriptor(journal_t *journal, { jbd2_journal_revoke_header_t *header; - if (is_journal_aborted(journal)) { - put_bh(descriptor); + if (is_journal_aborted(journal)) return; - } header = (jbd2_journal_revoke_header_t *)descriptor->b_data; header->r_count = cpu_to_be32(offset);