There is a case a stripe gets delayed forever. 1. a stripe finishes construction 2. a new bio hits the stripe 3. handle_stripe runs for the stripe. The stripe gets DELAYED bit set since construction can't run for new bio (the stripe is locked since step 1) Without log, handle_stripe will call ops_run_io. After IO finishes, the stripe gets unlocked and the stripe will restart and run construction for the new bio. With log, ops_run_io need to run two times. If the DELAYED bit set, the stripe can't enter into the handle_list, so the second ops_run_io doesn't run, which leaves the stripe stalled. Signed-off-by: Shaohua Li <shli@xxxxxx> --- drivers/md/raid5-cache.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 2dea05f..785749b1 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -474,6 +474,11 @@ int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh) return -EINVAL; set_bit(STRIPE_LOG_TRAPPED, &sh->state); + /* + * The stripe must enter state machine again to finish the write, so + * don't delay. + * */ + clear_bit(STRIPE_DELAYED, &sh->state); atomic_inc(&sh->count); mutex_lock(&log->io_mutex); -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
