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-rw-r--r--drivers/md/raid1-10.c14
-rw-r--r--drivers/md/raid1.c4
-rw-r--r--drivers/md/raid10.c8
3 files changed, 19 insertions, 7 deletions
diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
index 52469e460dab..c62bcb17c67b 100644
--- a/drivers/md/raid1-10.c
+++ b/drivers/md/raid1-10.c
@@ -152,3 +152,17 @@ static inline bool raid1_add_bio_to_plug(struct mddev *mddev, struct bio *bio,
return true;
}
+
+/*
+ * current->bio_list will be set under submit_bio() context, in this case bitmap
+ * io will be added to the list and wait for current io submission to finish,
+ * while current io submission must wait for bitmap io to be done. In order to
+ * avoid such deadlock, submit bitmap io asynchronously.
+ */
+static inline void raid1_prepare_flush_writes(struct bitmap *bitmap)
+{
+ if (current->bio_list)
+ md_bitmap_unplug_async(bitmap);
+ else
+ md_bitmap_unplug(bitmap);
+}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index c6b2abb7d185..334ed76d3c5a 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -794,7 +794,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
static void flush_bio_list(struct r1conf *conf, struct bio *bio)
{
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
- md_bitmap_unplug(conf->mddev->bitmap);
+ raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
@@ -1169,7 +1169,7 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
struct r1conf *conf = mddev->private;
struct bio *bio;
- if (from_schedule || current->bio_list) {
+ if (from_schedule) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
spin_unlock_irq(&conf->device_lock);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 21cdb85baba4..f890f549086b 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -910,9 +910,7 @@ static void flush_pending_writes(struct r10conf *conf)
__set_current_state(TASK_RUNNING);
blk_start_plug(&plug);
- /* flush any pending bitmap writes to disk
- * before proceeding w/ I/O */
- md_bitmap_unplug(conf->mddev->bitmap);
+ raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
@@ -1116,7 +1114,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
struct r10conf *conf = mddev->private;
struct bio *bio;
- if (from_schedule || current->bio_list) {
+ if (from_schedule) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
spin_unlock_irq(&conf->device_lock);
@@ -1128,7 +1126,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
/* we aren't scheduling, so we can do the write-out directly. */
bio = bio_list_get(&plug->pending);
- md_bitmap_unplug(mddev->bitmap);
+ raid1_prepare_flush_writes(mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */