It has added io_acct_set for raid0/raid5 io accounting and it needs to
alloc md_io_acct in the i/o path. They are free when the bios come back
from member disks. Now we don't have a method to monitor if those bios
are all come back. In the takeover process, it needs to free the raid0
memory resource including the memory pool for md_io_acct. But maybe some
bios are still not returned. When those bios are returned, it can cause
panic bcause of introducing NULL pointer or invalid address.
This patch adds io_acct_cnt. So when stopping raid0, it can use this
to wait until all bios come back.
Reported-by: Fine Fan <ffan@xxxxxxxxxx>
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
---
drivers/md/md.c | 10 +++++++++-
drivers/md/md.h | 8 +++++---
drivers/md/raid0.c | 8 ++++++++
drivers/md/raid0.h | 1 +
4 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9dc0175280b4..d6e9fa914087 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8600,15 +8600,18 @@ int acct_bioset_init(struct mddev *mddev)
{
int err = 0;
- if (!bioset_initialized(&mddev->io_acct_set))
+ if (!bioset_initialized(&mddev->io_acct_set)) {
+ atomic_set(&mddev->io_acct_cnt, 0);
err = bioset_init(&mddev->io_acct_set, BIO_POOL_SIZE,
offsetof(struct md_io_acct, bio_clone), 0);
+ }
return err;
}
EXPORT_SYMBOL_GPL(acct_bioset_init);
void acct_bioset_exit(struct mddev *mddev)
{
+ WARN_ON(atomic_read(&mddev->io_acct_cnt) != 0);
bioset_exit(&mddev->io_acct_set);
}
EXPORT_SYMBOL_GPL(acct_bioset_exit);
@@ -8617,12 +8620,15 @@ static void md_end_io_acct(struct bio *bio)
{
struct md_io_acct *md_io_acct = bio->bi_private;
struct bio *orig_bio = md_io_acct->orig_bio;
+ struct mddev *mddev = md_io_acct->mddev;
orig_bio->bi_status = bio->bi_status;
bio_end_io_acct(orig_bio, md_io_acct->start_time);
bio_put(bio);
bio_endio(orig_bio);
+
+ atomic_dec(&mddev->io_acct_cnt);
}
/*
@@ -8642,6 +8648,8 @@ void md_account_bio(struct mddev *mddev, struct bio **bio)
md_io_acct = container_of(clone, struct md_io_acct, bio_clone);
md_io_acct->orig_bio = *bio;
md_io_acct->start_time = bio_start_io_acct(*bio);
+ md_io_acct->mddev = mddev;
+ atomic_inc(&mddev->io_acct_cnt);
clone->bi_end_io = md_end_io_acct;
clone->bi_private = md_io_acct;
diff --git a/drivers/md/md.h b/drivers/md/md.h
index b4e2d8b87b61..29d30642e13f 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -513,6 +513,7 @@ struct mddev {
* metadata and bitmap writes
*/
struct bio_set io_acct_set; /* for raid0 and raid5 io accounting */
+ atomic_t io_acct_cnt;
/* Generic flush handling.
* The last to finish preflush schedules a worker to submit
@@ -710,9 +711,10 @@ struct md_thread {
};
struct md_io_acct {
- struct bio *orig_bio;
- unsigned long start_time;
- struct bio bio_clone;
+ struct bio *orig_bio;
+ unsigned long start_time;
+ struct bio bio_clone;
+ struct mddev *mddev;
};
#define THREAD_WAKEUP 0
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 857c49399c28..1d2e098e0d52 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -73,6 +73,8 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
*private_conf = ERR_PTR(-ENOMEM);
if (!conf)
return -ENOMEM;
+
+ init_waitqueue_head(&conf->wait_quiesce);
rdev_for_each(rdev1, mddev) {
pr_debug("md/raid0:%s: looking at %pg\n",
mdname(mddev),
@@ -754,6 +756,12 @@ static void *raid0_takeover(struct mddev *mddev)
static void raid0_quiesce(struct mddev *mddev, int quiesce)
{
+ struct r0conf *conf = mddev->private;
+
+ /* It doesn't use a separate struct to count how many bios are submitted
+ * to member disks to avoid memory alloc and performance decrease
+ */
+ wait_event(conf->wait_quiesce, atomic_read(&mddev->io_acct_cnt) == 0);
}
static struct md_personality raid0_personality=
diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h
index 3816e5477db1..560dec93d459 100644
--- a/drivers/md/raid0.h
+++ b/drivers/md/raid0.h
@@ -27,6 +27,7 @@ struct r0conf {
* by strip_zone->dev */
int nr_strip_zones;
enum r0layout layout;
+ wait_queue_head_t wait_quiesce;
};
#endif
--
2.32.0 (Apple Git-132)
