On Tue, Aug 02, 2011 at 12:52:42AM +0800, Christoph Hellwig wrote: > wb_check_background_flush is indeed what we're hitting. That means s_umount is NOT held by another queued writeback work. > See the trace output using a patch inspired by Curt's below: > > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush > <...>-4279 [000] 113.034052: writeback_grab_super_failed: bdi 7:0: sb_dev 0:0 nr_pages=9223372036854775807 sync_mode=0 kupdate=0 range_cyclic=1 background=1 reason=wb_check_background_flush What's that bdi 7:0? And sb_dev=0:0, nr_pages=9223372036854775807=0x7fffffffffffffff. All are indicating some special bdi/inode. Thanks, Fengguang -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
