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.
[ 6973.767999] RIP: 0010:mempool_free+0x52/0x80
[ 6973.786098] Call Trace:
[ 6973.786549] md_end_io_acct+0x31/0x40
[ 6973.787227] blk_update_request+0x224/0x380
[ 6973.787994] blk_mq_end_request+0x1a/0x130
[ 6973.788739] blk_complete_reqs+0x35/0x50
[ 6973.789456] __do_softirq+0xd7/0x2c8
[ 6973.790114] ? sort_range+0x20/0x20
[ 6973.790763] run_ksoftirqd+0x2a/0x40
[ 6973.791400] smpboot_thread_fn+0xb5/0x150
[ 6973.792114] kthread+0x10b/0x130
[ 6973.792724] ? set_kthread_struct+0x50/0x50
[ 6973.793491] ret_from_fork+0x1f/0x40
This patch trys to use ->active_io to count acct_io. The regression
tests have passed. And I did takeover from raid0 to raid5 and from
raid5 to raid0 while I/O is happening. This patch works well.
Reported-by: Fine Fan <ffan@xxxxxxxxxx>
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
---
drivers/md/md.c | 6 ++++++
drivers/md/md.h | 7 ++++---
2 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index da6370835c47..7f06eb953488 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8627,12 +8627,15 @@ 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);
+
+ percpu_ref_put(&mddev->active_io);
}
/*
@@ -8648,10 +8651,13 @@ void md_account_bio(struct mddev *mddev, struct bio **bio)
if (!blk_queue_io_stat(bdev->bd_disk->queue))
return;
+ percpu_ref_get(&mddev->active_io);
+
clone = bio_alloc_clone(bdev, *bio, GFP_NOIO, &mddev->io_acct_set);
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;
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 6335cb86e52e..e148e3c83b0d 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -710,9 +710,10 @@ struct md_thread {
};
struct md_io_acct {
- struct bio *orig_bio;
- unsigned long start_time;
- struct bio bio_clone;
+ struct mddev *mddev;
+ struct bio *orig_bio;
+ unsigned long start_time;
+ struct bio bio_clone;
};
#define THREAD_WAKEUP 0
--
2.32.0 (Apple Git-132)
