linux-stable.git/drivers/md/raid1.c, branch v5.13.2

md/raid1: properly indicate failure when ending a failed write request

2021-04-23T16:40:17+00:00

This patch addresses a data corruption bug in raid1 arrays using bitmaps.
Without this fix, the bitmap bits for the failed I/O end up being cleared.

Since we are in the failure leg of raid1_end_write_request, the request
either needs to be retried (R1BIO_WriteError) or failed (R1BIO_Degraded).

Fixes: eeba6809d8d5 ("md/raid1: end bio when the device faulty")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Paul Clements 
Signed-off-by: Song Liu

md: remove bio_alloc_mddev

2021-01-27T16:51:48+00:00

bio_alloc_mddev is never called with a NULL mddev, and ->bio_set is
initialized in md_run, so it always must be initialized as well.  Just
open code the remaining call to bio_alloc_bioset.

Signed-off-by: Christoph Hellwig 
Acked-by: Song Liu 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Chaitanya Kulkarni 
Acked-by: Damien Le Moal 
Signed-off-by: Jens Axboe

block: store a block_device pointer in struct bio

2021-01-25T01:17:20+00:00

Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device.  From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.

Signed-off-by: Christoph Hellwig 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe

block: remove the request_queue argument to the block_bio_remap tracepoint

2020-12-04T16:42:00+00:00

The request_queue can trivially be derived from the bio.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Acked-by: Tejun Heo 
Signed-off-by: Jens Axboe

writeback: remove bdi->congested_fn

2020-07-08T23:20:46+00:00

Except for pktdvd, the only places setting congested bits are file
systems that allocate their own backing_dev_info structures.  And
pktdvd is a deprecated driver that isn't useful in stack setup
either.  So remove the dead congested_fn stacking infrastructure.

Signed-off-by: Christoph Hellwig 
Acked-by: Song Liu 
Acked-by: David Sterba 
[axboe: fixup unused variables in bcache/request.c]
Signed-off-by: Jens Axboe

block: rename generic_make_request to submit_bio_noacct

2020-07-01T13:27:24+00:00

generic_make_request has always been very confusingly misnamed, so rename
it to submit_bio_noacct to make it clear that it is submit_bio minus
accounting and a few checks.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

md/raid1: release pending accounting for an I/O only after write-behind is also finished

2020-05-13T18:22:31+00:00

When using RAID1 and write-behind, md can deadlock when errors occur. With
write-behind, r1bio structs can be accounted by raid1 as queued but not
counted as pending. The pending count is dropped when the original bio is
returned complete but write-behind for the r1bio may still be active.

This breaks the accounting used in some conditions to know when the raid1
md device has reached an idle state. It can result in calls to
freeze_array deadlocking. freeze_array will never complete from a negative
"unqueued" value being calculated due to a queued count larger than the
pending count.

To properly account for write-behind, move the call to allow_barrier from
call_bio_endio to raid_end_bio_io. When using write-behind, md can call
call_bio_endio before all write-behind I/O is complete. Using
raid_end_bio_io for the point to call allow_barrier will release the
pending count at a point where all I/O for an r1bio, even write-behind, is
done.

Signed-off-by: David Jeffery 
Signed-off-by: Song Liu

md/raid1: introduce wait_for_serialization

2020-01-13T19:44:10+00:00

Previously, we call check_and_add_serial when serialization is
enabled for write IO, but it could allocate and free memory
back and forth.

Now, let's just get an element from memory pool with the new
function, then insert node to rb tree if no collision happens.

Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu

md/raid1: use bucket based mechanism for IO serialization

2020-01-13T19:44:10+00:00

Since raid1 had already used bucket based mechanism to reduce
the conflict between write IO and resync IO, it is possible to
speed up performance for io serialization with refer to the
same mechanism.

To align with the barrier bucket mechanism, we created arrays
(with the same number of BARRIER_BUCKETS_NR) for spinlock, rb
tree and waitqueue. Then we can reduce lock competition with
multiple spinlocks, boost search performance with multiple rb
trees and also reduce thundering herd problem with multiple
waitqueues.

Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu

md: introduce a new struct for IO serialization

2020-01-13T19:44:10+00:00

Obviously, IO serialization could cause the degradation of
performance a lot. In order to reduce the degradation, so a
rb interval tree is added in raid1 to speed up the check of
collision.

So, a rb root is needed in md_rdev, then abstract all the
serialize related members to a new struct (serial_in_rdev),
embed it into md_rdev.

Of course, we need to free the struct if it is not needed
anymore, so rdev/rdevs_uninit_serial are added accordingly.
And they should be called when destroty memory pool or can't
alloc memory.

And we need to consider to call mddev_destroy_serial_pool
in case serialize_policy/write-behind is disabled, bitmap
is destroyed or in __md_stop_writes.

Signed-off-by: Guoqing Jiang 
Signed-off-by: Song Liu