From 94568f64af50bb37c418b200449698cfe7e1da5f Mon Sep 17 00:00:00 2001 From: Artur Paszkiewicz Date: Tue, 4 Apr 2017 13:13:56 +0200 Subject: raid5-ppl: move no_mem_stripes to struct ppl_conf Use a single no_mem_stripes list instead of per member device lists for handling stripes that need retrying in case of failed io_unit allocation. Because io_units are allocated from a memory pool shared between all member disks, the no_mem_stripes list should be checked when an io_unit for any member is freed. This fixes a deadlock that could happen if there are stripes in more than one no_mem_stripes list. Signed-off-by: Artur Paszkiewicz Signed-off-by: Shaohua Li --- drivers/md/raid5-ppl.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) (limited to 'drivers/md/raid5-ppl.c') diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c index 86ea9addb51a..355cf3581ef8 100644 --- a/drivers/md/raid5-ppl.c +++ b/drivers/md/raid5-ppl.c @@ -107,6 +107,10 @@ struct ppl_conf { /* used only for recovery */ int recovered_entries; int mismatch_count; + + /* stripes to retry if failed to allocate io_unit */ + struct list_head no_mem_stripes; + spinlock_t no_mem_stripes_lock; }; struct ppl_log { @@ -119,8 +123,6 @@ struct ppl_log { * always at the end of io_list */ spinlock_t io_list_lock; struct list_head io_list; /* all io_units of this log */ - struct list_head no_mem_stripes;/* stripes to retry if failed to - * allocate io_unit */ }; #define PPL_IO_INLINE_BVECS 32 @@ -347,9 +349,9 @@ int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh) atomic_inc(&sh->count); if (ppl_log_stripe(log, sh)) { - spin_lock_irq(&log->io_list_lock); - list_add_tail(&sh->log_list, &log->no_mem_stripes); - spin_unlock_irq(&log->io_list_lock); + spin_lock_irq(&ppl_conf->no_mem_stripes_lock); + list_add_tail(&sh->log_list, &ppl_conf->no_mem_stripes); + spin_unlock_irq(&ppl_conf->no_mem_stripes_lock); } mutex_unlock(&log->io_mutex); @@ -492,25 +494,32 @@ void ppl_write_stripe_run(struct r5conf *conf) static void ppl_io_unit_finished(struct ppl_io_unit *io) { struct ppl_log *log = io->log; + struct ppl_conf *ppl_conf = log->ppl_conf; unsigned long flags; pr_debug("%s: seq: %llu\n", __func__, io->seq); - spin_lock_irqsave(&log->io_list_lock, flags); + local_irq_save(flags); + spin_lock(&log->io_list_lock); list_del(&io->log_sibling); - mempool_free(io, log->ppl_conf->io_pool); + spin_unlock(&log->io_list_lock); + + mempool_free(io, ppl_conf->io_pool); + + spin_lock(&ppl_conf->no_mem_stripes_lock); + if (!list_empty(&ppl_conf->no_mem_stripes)) { + struct stripe_head *sh; - if (!list_empty(&log->no_mem_stripes)) { - struct stripe_head *sh = list_first_entry(&log->no_mem_stripes, - struct stripe_head, - log_list); + sh = list_first_entry(&ppl_conf->no_mem_stripes, + struct stripe_head, log_list); list_del_init(&sh->log_list); set_bit(STRIPE_HANDLE, &sh->state); raid5_release_stripe(sh); } + spin_unlock(&ppl_conf->no_mem_stripes_lock); - spin_unlock_irqrestore(&log->io_list_lock, flags); + local_irq_restore(flags); } void ppl_stripe_write_finished(struct stripe_head *sh) @@ -1135,6 +1144,8 @@ int ppl_init_log(struct r5conf *conf) } atomic64_set(&ppl_conf->seq, 0); + INIT_LIST_HEAD(&ppl_conf->no_mem_stripes); + spin_lock_init(&ppl_conf->no_mem_stripes_lock); if (!mddev->external) { ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid)); @@ -1150,7 +1161,6 @@ int ppl_init_log(struct r5conf *conf) mutex_init(&log->io_mutex); spin_lock_init(&log->io_list_lock); INIT_LIST_HEAD(&log->io_list); - INIT_LIST_HEAD(&log->no_mem_stripes); log->ppl_conf = ppl_conf; log->rdev = rdev; -- cgit v1.2.3