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Merge tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull block handle updates from Christian Brauner:
"Last cycle we changed opening of block devices, and opening a block
device would return a bdev_handle. This allowed us to implement
support for restricting and forbidding writes to mounted block
devices. It was accompanied by converting and adding helpers to
operate on bdev_handles instead of plain block devices.
That was already a good step forward but ultimately it isn't necessary
to have special purpose helpers for opening block devices internally
that return a bdev_handle.
Fundamentally, opening a block device internally should just be
equivalent to opening files. So now all internal opens of block
devices return files just as a userspace open would. Instead of
introducing a separate indirection into bdev_open_by_*() via struct
bdev_handle bdev_file_open_by_*() is made to just return a struct
file. Opening and closing a block device just becomes equivalent to
opening and closing a file.
This all works well because internally we already have a pseudo fs for
block devices and so opening block devices is simple. There's a few
places where we needed to be careful such as during boot when the
kernel is supposed to mount the rootfs directly without init doing it.
Here we need to take care to ensure that we flush out any asynchronous
file close. That's what we already do for opening, unpacking, and
closing the initramfs. So nothing new here.
The equivalence of opening and closing block devices to regular files
is a win in and of itself. But it also has various other advantages.
We can remove struct bdev_handle completely. Various low-level helpers
are now private to the block layer. Other helpers were simply
removable completely.
A follow-up series that is already reviewed build on this and makes it
possible to remove bdev->bd_inode and allows various clean ups of the
buffer head code as well. All places where we stashed a bdev_handle
now just stash a file and use simple accessors to get to the actual
block device which was already the case for bdev_handle"
* tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
block: remove bdev_handle completely
block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access
bdev: remove bdev pointer from struct bdev_handle
bdev: make struct bdev_handle private to the block layer
bdev: make bdev_{release, open_by_dev}() private to block layer
bdev: remove bdev_open_by_path()
reiserfs: port block device access to file
ocfs2: port block device access to file
nfs: port block device access to files
jfs: port block device access to file
f2fs: port block device access to files
ext4: port block device access to file
erofs: port device access to file
btrfs: port device access to file
bcachefs: port block device access to file
target: port block device access to file
s390: port block device access to file
nvme: port block device access to file
block2mtd: port device access to files
bcache: port block device access to files
...
md_start_sync() will suspend the array if there are spares that can be
added or removed from conf, however, if reshape is still in progress,
this won't happen at all or data will be corrupted(remove_and_add_spares
won't be called from md_choose_sync_action for reshape), hence there is
no need to suspend the array if reshape is not done yet.
Meanwhile, there is a potential deadlock for raid456:
1) reshape is interrupted;
2) set one of the disk WantReplacement, and add a new disk to the array,
however, recovery won't start until the reshape is finished;
3) then issue an IO across reshpae position, this IO will wait for
reshape to make progress;
4) continue to reshape, then md_start_sync() found there is a spare disk
that can be added to conf, mddev_suspend() is called;
Step 4 and step 3 is waiting for each other, deadlock triggered. Noted
this problem is found by code review, and it's not reporduced yet.
Fix this porblem by don't suspend the array for interrupted reshape,
this is safe because conf won't be changed until reshape is done.
Fixes: bc08041b32 ("md: suspend array in md_start_sync() if array need reconfiguration")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-6-yukuai1@huaweicloud.com
Currently, if reshape is interrupted, then reassemble the array will
register sync_thread directly from pers->run(), in this case
'MD_RECOVERY_RUNNING' is set directly, however, there is no guarantee
that md_do_sync() will be executed, hence stop_sync_thread() will hang
because 'MD_RECOVERY_RUNNING' can't be cleared.
Last patch make sure that md_do_sync() will set MD_RECOVERY_DONE,
however, following hang can still be triggered by dm-raid test
shell/lvconvert-raid-reshape.sh occasionally:
[root@fedora ~]# cat /proc/1982/stack
[<0>] stop_sync_thread+0x1ab/0x270 [md_mod]
[<0>] md_frozen_sync_thread+0x5c/0xa0 [md_mod]
[<0>] raid_presuspend+0x1e/0x70 [dm_raid]
[<0>] dm_table_presuspend_targets+0x40/0xb0 [dm_mod]
[<0>] __dm_destroy+0x2a5/0x310 [dm_mod]
[<0>] dm_destroy+0x16/0x30 [dm_mod]
[<0>] dev_remove+0x165/0x290 [dm_mod]
[<0>] ctl_ioctl+0x4bb/0x7b0 [dm_mod]
[<0>] dm_ctl_ioctl+0x11/0x20 [dm_mod]
[<0>] vfs_ioctl+0x21/0x60
[<0>] __x64_sys_ioctl+0xb9/0xe0
[<0>] do_syscall_64+0xc6/0x230
[<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74
Meanwhile mddev->recovery is:
MD_RECOVERY_RUNNING |
MD_RECOVERY_INTR |
MD_RECOVERY_RESHAPE |
MD_RECOVERY_FROZEN
Fix this problem by remove the code to register sync_thread directly
from raid10 and raid5. And let md_check_recovery() to register
sync_thread.
Fixes: f67055780c ("[PATCH] md: Checkpoint and allow restart of raid5 reshape")
Fixes: f52f5c71f3 ("md: fix stopping sync thread")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-5-yukuai1@huaweicloud.com
stop_sync_thread() will interrupt md_do_sync(), and md_do_sync() must
set MD_RECOVERY_DONE, so that follow up md_check_recovery() will
unregister sync_thread, clear MD_RECOVERY_RUNNING and wake up
stop_sync_thread().
If MD_RECOVERY_WAIT is set or the array is read-only, md_do_sync() will
return without setting MD_RECOVERY_DONE, and after commit f52f5c71f3
("md: fix stopping sync thread"), dm-raid switch from
md_reap_sync_thread() to stop_sync_thread() to unregister sync_thread
from md_stop() and md_stop_writes(), causing the test
shell/lvconvert-raid-reshape.sh hang.
We shouldn't switch back to md_reap_sync_thread() because it's
problematic in the first place. Fix the problem by making sure
md_do_sync() will set MD_RECOVERY_DONE.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Closes: https://lore.kernel.org/all/ece2b06f-d647-6613-a534-ff4c9bec1142@redhat.com/
Fixes: d5d885fd51 ("md: introduce new personality funciton start()")
Fixes: 5fd6c1dce0 ("[PATCH] md: allow checkpoint of recovery with version-1 superblock")
Fixes: f52f5c71f3 ("md: fix stopping sync thread")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-4-yukuai1@huaweicloud.com
Usually if the array is not read-write, md_check_recovery() won't
register new sync_thread in the first place. And if the array is
read-write and sync_thread is registered, md_set_readonly() will
unregister sync_thread before setting the array read-only. md/raid
follow this behavior hence there is no problem.
After commit f52f5c71f3 ("md: fix stopping sync thread"), following
hang can be triggered by test shell/integrity-caching.sh:
1) array is read-only. dm-raid update super block:
rs_update_sbs
ro = mddev->ro
mddev->ro = 0
-> set array read-write
md_update_sb
2) register new sync thread concurrently.
3) dm-raid set array back to read-only:
rs_update_sbs
mddev->ro = ro
4) stop the array:
raid_dtr
md_stop
stop_sync_thread
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_wakeup_thread_directly(mddev->sync_thread);
wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
5) sync thread done:
md_do_sync
set_bit(MD_RECOVERY_DONE, &mddev->recovery);
md_wakeup_thread(mddev->thread);
6) daemon thread can't unregister sync thread:
md_check_recovery
if (!md_is_rdwr(mddev) &&
!test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
return;
-> -> MD_RECOVERY_RUNNING can't be cleared, hence step 4 hang;
The root cause is that dm-raid manipulate 'mddev->ro' by itself,
however, dm-raid really should stop sync thread before setting the
array read-only. Unfortunately, I need to read more code before I
can refacter the handler of 'mddev->ro' in dm-raid, hence let's fix
the problem the easy way for now to prevent dm-raid regression.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Closes: https://lore.kernel.org/all/9801e40-8ac7-e225-6a71-309dcf9dc9aa@redhat.com/
Fixes: ecbfb9f118 ("dm raid: add raid level takeover support")
Fixes: f52f5c71f3 ("md: fix stopping sync thread")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-3-yukuai1@huaweicloud.com
mddev_suspend() never stop sync_thread, hence it doesn't make sense to
ignore suspended array in md_check_recovery(), which might cause
sync_thread can't be unregistered.
After commit f52f5c71f3 ("md: fix stopping sync thread"), following
hang can be triggered by test shell/integrity-caching.sh:
1) suspend the array:
raid_postsuspend
mddev_suspend
2) stop the array:
raid_dtr
md_stop
__md_stop_writes
stop_sync_thread
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_wakeup_thread_directly(mddev->sync_thread);
wait_event(..., !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3) sync thread done:
md_do_sync
set_bit(MD_RECOVERY_DONE, &mddev->recovery);
md_wakeup_thread(mddev->thread);
4) daemon thread can't unregister sync thread:
md_check_recovery
if (mddev->suspended)
return; -> return directly
md_read_sync_thread
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
-> MD_RECOVERY_RUNNING can't be cleared, hence step 2 hang;
This problem is not just related to dm-raid, fix it by ignoring
suspended array in md_check_recovery(). And follow up patches will
improve dm-raid better to frozen sync thread during suspend.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Closes: https://lore.kernel.org/all/8fb335e-6d2c-dbb5-d7-ded8db5145a@redhat.com/
Fixes: 68866e425b ("MD: no sync IO while suspended")
Fixes: f52f5c71f3 ("md: fix stopping sync thread")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-2-yukuai1@huaweicloud.com
submit_flushes
atomic_set(&mddev->flush_pending, 1);
rdev_for_each_rcu(rdev, mddev)
atomic_inc(&mddev->flush_pending);
bi->bi_end_io = md_end_flush
submit_bio(bi);
/* flush io is done first */
md_end_flush
if (atomic_dec_and_test(&mddev->flush_pending))
percpu_ref_put(&mddev->active_io)
-> active_io is not released
if (atomic_dec_and_test(&mddev->flush_pending))
-> missing release of active_io
For consequence, mddev_suspend() will wait for 'active_io' to be zero
forever.
Fix this problem by releasing 'active_io' in submit_flushes() if
'flush_pending' is decreased to zero.
Fixes: fa2bbff7b0 ("md: synchronize flush io with array reconfiguration")
Cc: stable@vger.kernel.org # v6.1+
Reported-by: Blazej Kucman <blazej.kucman@linux.intel.com>
Closes: https://lore.kernel.org/lkml/20240130172524.0000417b@linux.intel.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240201092559.910982-7-yukuai1@huaweicloud.com
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Merge tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- tcp, fc, and rdma target fixes (Maurizio, Daniel, Hannes,
Christoph)
- discard fixes and improvements (Christoph)
- timeout debug improvements (Keith, Max)
- various cleanups (Daniel, Max, Giuxen)
- trace event string fixes (Arnd)
- shadow doorbell setup on reset fix (William)
- a write zeroes quirk for SK Hynix (Jim)
- MD pull request via Song:
- Sparse warning since v6.0 (Bart)
- /proc/mdstat regression since v6.7 (Yu Kuai)
- Use symbolic error value (Christian)
- IO Priority documentation update (Christian)
- Fix for accessing queue limits without having entered the queue
(Christoph, me)
- Fix for loop dio support (Christoph)
- Move null_blk off deprecated ida interface (Christophe)
- Ensure nbd initializes full msghdr (Eric)
- Fix for a regression with the folio conversion, which is now easier
to hit because of an unrelated change (Matthew)
- Remove redundant check in virtio-blk (Li)
- Fix for a potential hang in sbitmap (Ming)
- Fix for partial zone appending (Damien)
- Misc changes and fixes (Bart, me, Kemeng, Dmitry)
* tag 'for-6.8/block-2024-01-18' of git://git.kernel.dk/linux: (45 commits)
Documentation: block: ioprio: Update schedulers
loop: fix the the direct I/O support check when used on top of block devices
blk-mq: Remove the hctx 'run' debugfs attribute
nbd: always initialize struct msghdr completely
block: Fix iterating over an empty bio with bio_for_each_folio_all
block: bio-integrity: fix kcalloc() arguments order
virtio_blk: remove duplicate check if queue is broken in virtblk_done
sbitmap: remove stale comment in sbq_calc_wake_batch
block: Correct a documentation comment in blk-cgroup.c
null_blk: Remove usage of the deprecated ida_simple_xx() API
block: ensure we hold a queue reference when using queue limits
blk-mq: rename blk_mq_can_use_cached_rq
block: print symbolic error name instead of error code
blk-mq: fix IO hang from sbitmap wakeup race
nvmet-rdma: avoid circular locking dependency on install_queue()
nvmet-tcp: avoid circular locking dependency on install_queue()
nvme-pci: set doorbell config before unquiescing
block: fix partial zone append completion handling in req_bio_endio()
block/iocost: silence warning on 'last_period' potentially being unused
md/raid1: Use blk_opf_t for read and write operations
...
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Merge tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
"Pretty quiet round this time around. This contains:
- NVMe updates via Keith:
- nvme fabrics spec updates (Guixin, Max)
- nvme target udpates (Guixin, Evan)
- nvme attribute refactoring (Daniel)
- nvme-fc numa fix (Keith)
- MD updates via Song:
- Fix/Cleanup RCU usage from conf->disks[i].rdev (Yu Kuai)
- Fix raid5 hang issue (Junxiao Bi)
- Add Yu Kuai as Reviewer of the md subsystem
- Remove deprecated flavors (Song Liu)
- raid1 read error check support (Li Nan)
- Better handle events off-by-1 case (Alex Lyakas)
- Efficiency improvements for passthrough (Kundan)
- Support for mapping integrity data directly (Keith)
- Zoned write fix (Damien)
- rnbd fixes (Kees, Santosh, Supriti)
- Default to a sane discard size granularity (Christoph)
- Make the default max transfer size naming less confusing
(Christoph)
- Remove support for deprecated host aware zoned model (Christoph)
- Misc fixes (me, Li, Matthew, Min, Ming, Randy, liyouhong, Daniel,
Bart, Christoph)"
* tag 'for-6.8/block-2024-01-08' of git://git.kernel.dk/linux: (78 commits)
block: Treat sequential write preferred zone type as invalid
block: remove disk_clear_zoned
sd: remove the !ZBC && blk_queue_is_zoned case in sd_read_block_characteristics
drivers/block/xen-blkback/common.h: Fix spelling typo in comment
blk-cgroup: fix rcu lockdep warning in blkg_lookup()
blk-cgroup: don't use removal safe list iterators
block: floor the discard granularity to the physical block size
mtd_blkdevs: use the default discard granularity
bcache: use the default discard granularity
zram: use the default discard granularity
null_blk: use the default discard granularity
nbd: use the default discard granularity
ubd: use the default discard granularity
block: default the discard granularity to sector size
bcache: discard_granularity should not be smaller than a sector
block: remove two comments in bio_split_discard
block: rename and document BLK_DEF_MAX_SECTORS
loop: don't abuse BLK_DEF_MAX_SECTORS
aoe: don't abuse BLK_DEF_MAX_SECTORS
null_blk: don't cap max_hw_sectors to BLK_DEF_MAX_SECTORS
...
Commit cf1b6d4441 ("md: simplify md_seq_ops") introduce following
regressions:
1) If list all_mddevs is emptly, personalities and unused devices won't
be showed to user anymore.
2) If seq_file buffer overflowed from md_seq_show(), then md_seq_start()
will be called again, hence personalities will be showed to user
again.
3) If seq_file buffer overflowed from md_seq_stop(), seq_read_iter()
doesn't handle this, hence unused devices won't be showed to user.
Fix above problems by printing personalities and unused devices in
md_seq_show().
Fixes: cf1b6d4441 ("md: simplify md_seq_ops")
Cc: stable@vger.kernel.org # v6.7+
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240109133957.2975272-1-yukuai1@huaweicloud.com
md-multipath has been marked as deprecated for 2.5 years. Remove it.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231214222107.2016042-3-song@kernel.org
md-linear has been marked as deprecated for 2.5 years. Remove it.
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Cc: Guoqing Jiang <guoqing.jiang@linux.dev>
Cc: Mateusz Grzonka <mateusz.grzonka@intel.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20231214222107.2016042-2-song@kernel.org
After commit db5e653d7c ("md: delay choosing sync action to
md_start_sync()"), md_start_sync() will hold 'reconfig_mutex', however,
in order to make sure event_work is done, __md_stop() will flush
workqueue with reconfig_mutex grabbed, hence if sync_work is still
pending, deadlock will be triggered.
Fortunately, former pacthes to fix stopping sync_thread already make sure
all sync_work is done already, hence such deadlock is not possible
anymore. However, in order not to cause confusions for people by this
implicit dependency, delay flushing event_work to dm-raid where
'reconfig_mutex' is not held, and add some comments to emphasize that
the workqueue can't be flushed with 'reconfig_mutex'.
Fixes: db5e653d7c ("md: delay choosing sync action to md_start_sync()")
Depends-on: f52f5c71f3 ("md: fix stopping sync thread")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Upon assembling the array, both kernel and mdadm allow the devices to have event
counter difference of 1, and still consider them as up-to-date.
However, a device whose event count is behind by 1, may in fact not be up-to-date,
and array resync with such a device may cause data corruption.
To avoid this, consult the superblock of the freshest device about the status
of a device, whose event counter is behind by 1.
Signed-off-by: Alex Lyakas <alex.lyakas@zadara.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/1702470271-16073-1-git-send-email-alex.lyakas@zadara.com
New mddev_resume() calls are added to synchronize IO with array
reconfiguration, however, this introduces a performance regression while
adding it in md_start_sync():
1) someone sets MD_RECOVERY_NEEDED first;
2) daemon thread grabs reconfig_mutex, then clears MD_RECOVERY_NEEDED and
queues a new sync work;
3) daemon thread releases reconfig_mutex;
4) in md_start_sync
a) check that there are spares that can be added/removed, then suspend
the array;
b) remove_and_add_spares may not be called, or called without really
add/remove spares;
c) resume the array, then set MD_RECOVERY_NEEDED again!
Loop between 2 - 4, then mddev_suspend() will be called quite often, for
consequence, normal IO will be quite slow.
Fix this problem by don't set MD_RECOVERY_NEEDED again in md_start_sync(),
hence the loop will be broken.
Fixes: bc08041b32 ("md: suspend array in md_start_sync() if array need reconfiguration")
Suggested-by: Song Liu <song@kernel.org>
Reported-by: Janpieter Sollie <janpieter.sollie@edpnet.be>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218200
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231207020724.2797445-1-yukuai1@huaweicloud.com
Currently sync thread is stopped from multiple contex:
- idle_sync_thread
- frozen_sync_thread
- __md_stop_writes
- md_set_readonly
- do_md_stop
And there are some problems:
1) sync_work is flushed while reconfig_mutex is grabbed, this can
deadlock because the work function will grab reconfig_mutex as well.
2) md_reap_sync_thread() can't be called directly while md_do_sync() is
not finished yet, for example, commit 130443d60b ("md: refactor
idle/frozen_sync_thread() to fix deadlock").
3) If MD_RECOVERY_RUNNING is not set, there is no need to stop
sync_thread at all because sync_thread must not be registered.
Factor out a helper stop_sync_thread(), so that above contex will behave
the same. Fix 1) by flushing sync_work after reconfig_mutex is released,
before waiting for sync_thread to be done; Fix 2) bt letting daemon thread
to unregister sync_thread; Fix 3) by always checking MD_RECOVERY_RUNNING
first.
Fixes: db5e653d7c ("md: delay choosing sync action to md_start_sync()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231205094215.1824240-4-yukuai1@huaweicloud.com
If md_set_readonly() failed, the array could still be read-write, however
'MD_RECOVERY_FROZEN' could still be set, which leave the array in an
abnormal state that sync or recovery can't continue anymore.
Hence make sure the flag is cleared after md_set_readonly() returns.
Fixes: 88724bfa68 ("md: wait for pending superblock updates before switching to read-only")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231205094215.1824240-3-yukuai1@huaweicloud.com
Commit ac61978196 ("md: use separate work_struct for md_start_sync()")
use a new sync_work to replace del_work, however, stop_sync_thread() and
__md_stop_writes() was trying to wait for sync_thread to be done, hence
they should switch to use sync_work as well.
Noted that md_start_sync() from sync_work will grab 'reconfig_mutex',
hence other contex can't held the same lock to flush work, and this will
be fixed in later patches.
Fixes: ac61978196 ("md: use separate work_struct for md_start_sync()")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231205094215.1824240-2-yukuai1@huaweicloud.com
Currently rcu is used to protect iterating rdev from submit_flushes():
submit_flushes remove_and_add_spares
synchronize_rcu
pers->hot_remove_disk()
rcu_read_lock()
rdev_for_each_rcu
if (rdev->raid_disk >= 0)
rdev->radi_disk = -1;
atomic_inc(&rdev->nr_pending)
rcu_read_unlock()
bi = bio_alloc_bioset()
bi->bi_end_io = md_end_flush
bi->private = rdev
submit_bio
// issue io for removed rdev
Fix this problem by grabbing 'acive_io' before iterating rdev, make sure
that remove_and_add_spares() won't concurrent with submit_flushes().
Fixes: a2826aa92e ("md: support barrier requests on all personalities.")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231129020234.1586910-1-yukuai1@huaweicloud.com
rcu is not used correctly here, because synchronize_rcu() is called
before replacing old value, for example:
remove_and_add_spares // other path
synchronize_rcu
// called before replacing old value
set_bit(RemoveSynchronized)
rcu_read_lock()
rdev = conf->mirros[].rdev
pers->hot_remove_disk
conf->mirros[].rdev = NULL;
if (!test_bit(RemoveSynchronized))
synchronize_rcu
/*
* won't be called, and won't wait
* for concurrent readers to be done.
*/
// access rdev after remove_and_add_spares()
rcu_read_unlock()
Fortunately, there is a separate rcu protection to prevent such rdev
to be freed:
md_kick_rdev_from_array //other path
rcu_read_lock()
rdev = conf->mirros[].rdev
list_del_rcu(&rdev->same_set)
rcu_read_unlock()
/*
* rdev can be removed from conf, but
* rdev won't be freed.
*/
synchronize_rcu()
free rdev
Hence remove this useless flag and prepare to remove rcu protection to
access rdev from 'conf'.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231125081604.3939938-2-yukuai1@huaweicloud.com
commit 5e2cf333b7 ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
introduced a hung bug and will be reverted in next patch, since the issue
that commit is fixing is due to md superblock write is throttled by wbt,
to fix it, we can have superblock write bypass block layer throttle.
Fixes: 5e2cf333b7 ("md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d")
Cc: stable@vger.kernel.org # v5.19+
Suggested-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231108182216.73611-1-junxiao.bi@oracle.com
md_end_clone_io() may overwrite error status in orig_bio->bi_status with
BLK_STS_OK. This could happen when orig_bio has BIO_CHAIN (split by
md_submit_bio => bio_split_to_limits, for example). As a result, upper
layer may miss error reported from md (or the device) and consider the
failed IO was successful.
Fix this by only update orig_bio->bi_status when current bio reports
error and orig_bio is BLK_STS_OK. This is the same behavior as
__bio_chain_endio().
Fixes: 10764815ff ("md: add io accounting for raid0 and raid5")
Cc: stable@vger.kernel.org # v5.14+
Reported-by: Bhanu Victor DiCara <00bvd0+linux@gmail.com>
Closes: https://lore.kernel.org/regressions/5727380.DvuYhMxLoT@bvd0/
Signed-off-by: Song Liu <song@kernel.org>
Tested-by: Xiao Ni <xni@redhat.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
To help make the move of sysctls out of kernel/sysctl.c not incur a size
penalty sysctl has been changed to allow us to not require the sentinel, the
final empty element on the sysctl array. Joel Granados has been doing all this
work. On the v6.6 kernel we got the major infrastructure changes required to
support this. For v6.7-rc1 we have all arch/ and drivers/ modified to remove
the sentinel. Both arch and driver changes have been on linux-next for a bit
less than a month. It is worth re-iterating the value:
- this helps reduce the overall build time size of the kernel and run time
memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move sysctls
out from kernel/sysctl.c to their own files
For v6.8-rc1 expect removal of all the sentinels and also then the unneeded
check for procname == NULL.
The last 2 patches are fixes recently merged by Krister Johansen which allow
us again to use softlockup_panic early on boot. This used to work but the
alias work broke it. This is useful for folks who want to detect softlockups
super early rather than wait and spend money on cloud solutions with nothing
but an eventual hung kernel. Although this hadn't gone through linux-next it's
also a stable fix, so we might as well roll through the fixes now.
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Merge tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"To help make the move of sysctls out of kernel/sysctl.c not incur a
size penalty sysctl has been changed to allow us to not require the
sentinel, the final empty element on the sysctl array. Joel Granados
has been doing all this work. On the v6.6 kernel we got the major
infrastructure changes required to support this. For v6.7-rc1 we have
all arch/ and drivers/ modified to remove the sentinel. Both arch and
driver changes have been on linux-next for a bit less than a month. It
is worth re-iterating the value:
- this helps reduce the overall build time size of the kernel and run
time memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move
sysctls out from kernel/sysctl.c to their own files
For v6.8-rc1 expect removal of all the sentinels and also then the
unneeded check for procname == NULL.
The last two patches are fixes recently merged by Krister Johansen
which allow us again to use softlockup_panic early on boot. This used
to work but the alias work broke it. This is useful for folks who want
to detect softlockups super early rather than wait and spend money on
cloud solutions with nothing but an eventual hung kernel. Although
this hadn't gone through linux-next it's also a stable fix, so we
might as well roll through the fixes now"
* tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits)
watchdog: move softlockup_panic back to early_param
proc: sysctl: prevent aliased sysctls from getting passed to init
intel drm: Remove now superfluous sentinel element from ctl_table array
Drivers: hv: Remove now superfluous sentinel element from ctl_table array
raid: Remove now superfluous sentinel element from ctl_table array
fw loader: Remove the now superfluous sentinel element from ctl_table array
sgi-xp: Remove the now superfluous sentinel element from ctl_table array
vrf: Remove the now superfluous sentinel element from ctl_table array
char-misc: Remove the now superfluous sentinel element from ctl_table array
infiniband: Remove the now superfluous sentinel element from ctl_table array
macintosh: Remove the now superfluous sentinel element from ctl_table array
parport: Remove the now superfluous sentinel element from ctl_table array
scsi: Remove now superfluous sentinel element from ctl_table array
tty: Remove now superfluous sentinel element from ctl_table array
xen: Remove now superfluous sentinel element from ctl_table array
hpet: Remove now superfluous sentinel element from ctl_table array
c-sky: Remove now superfluous sentinel element from ctl_talbe array
powerpc: Remove now superfluous sentinel element from ctl_table arrays
riscv: Remove now superfluous sentinel element from ctl_table array
x86/vdso: Remove now superfluous sentinel element from ctl_table array
...
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Merge tag 'for-6.7/block-2023-10-30' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- Improvements to the queue_rqs() support, and adding null_blk support
for that as well (Chengming)
- Series improving badblocks support (Coly)
- Key store support for sed-opal (Greg)
- IBM partition string handling improvements (Jan)
- Make number of ublk devices supported configurable (Mike)
- Cancelation improvements for ublk (Ming)
- MD pull requests via Song:
- Handle timeout in md-cluster, by Denis Plotnikov
- Cleanup pers->prepare_suspend, by Yu Kuai
- Rewrite mddev_suspend(), by Yu Kuai
- Simplify md_seq_ops, by Yu Kuai
- Reduce unnecessary locking array_state_store(), by Mariusz
Tkaczyk
- Make rdev add/remove independent from daemon thread, by Yu Kuai
- Refactor code around quiesce() and mddev_suspend(), by Yu Kuai
- NVMe pull request via Keith:
- nvme-auth updates (Mark)
- nvme-tcp tls (Hannes)
- nvme-fc annotaions (Kees)
- Misc cleanups and improvements (Jiapeng, Joel)
* tag 'for-6.7/block-2023-10-30' of git://git.kernel.dk/linux: (95 commits)
block: ublk_drv: Remove unused function
md: cleanup pers->prepare_suspend()
nvme-auth: allow mixing of secret and hash lengths
nvme-auth: use transformed key size to create resp
nvme-auth: alloc nvme_dhchap_key as single buffer
nvmet-tcp: use 'spin_lock_bh' for state_lock()
powerpc/pseries: PLPKS SED Opal keystore support
block: sed-opal: keystore access for SED Opal keys
block:sed-opal: SED Opal keystore
ublk: simplify aborting request
ublk: replace monitor with cancelable uring_cmd
ublk: quiesce request queue when aborting queue
ublk: rename mm_lock as lock
ublk: move ublk_cancel_dev() out of ub->mutex
ublk: make sure io cmd handled in submitter task context
ublk: don't get ublk device reference in ublk_abort_queue()
ublk: Make ublks_max configurable
ublk: Limit dev_id/ub_number values
md-cluster: check for timeout while a new disk adding
nvme: rework NVME_AUTH Kconfig selection
...
Convert md to use bdev_open_by_dev() and pass the handle around. We also
don't need the 'Holder' flag anymore so remove it.
CC: linux-raid@vger.kernel.org
CC: Song Liu <song@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-11-jack@suse.cz
Signed-off-by: Christian Brauner <brauner@kernel.org>
pers->prepare_suspend() is not used anymore and can be removed.
Reverts following three commit:
- commit 431e61257d ("md: export md_is_rdwr() and is_md_suspended()")
- commit 3e00777d51 ("md: add a new api prepare_suspend() in
md_personality")
- commit 868bba54a3 ("md/raid5: fix a deadlock in the case that reshape
is interrupted")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231016100240.540474-1-yukuai1@huaweicloud.com
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)
Remove sentinel from raid_table
Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Now that the old apis are removed, __mddev_suspend/resume() can be
renamed to their original names.
This is done by:
sed -i "s/__mddev_suspend/mddev_suspend/g" *.[ch]
sed -i "s/__mddev_resume/mddev_resume/g" *.[ch]
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-20-yukuai1@huaweicloud.com
Now that mddev_suspend() and mddev_resume() is not used anywhere, remove
them, and remove 'MD_ALLOW_SB_UPDATE' and 'MD_UPDATING_SB' as well.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-19-yukuai1@huaweicloud.com
So that io won't concurrent with array reconfiguration, and it's safe to
suspend the array directly because normal io won't rely on
md_start_sync().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-18-yukuai1@huaweicloud.com
Now that except for stopping the array, all the callers already suspend
the array, there is no need to suspend anymore, hence remove the second
parameter.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-15-yukuai1@huaweicloud.com
mddev_create/destroy_serial_pool() will be called from several places
where mddev_suspend() will be called later.
Prepare to remove the mddev_suspend() from
mddev_create/destroy_serial_pool().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-14-yukuai1@huaweicloud.com
'reconfig_mutex' will be grabbed before these ioctls, suspend array
before holding the lock, so that io won't concurrent with array
reconfiguration through ioctls.
This is not hot path, so performance is not concerned.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-13-yukuai1@huaweicloud.com
User can write 'remove' and 're-add' to trigger array reconfiguration
through sysfs, suspend array in this case so that io won't concurrent
with array reconfiguration.
And now that all the caller of add_bound_rdev() alread suspend the
array, remove mddev_suspend/resume() from add_bound_rdev() as well.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-12-yukuai1@huaweicloud.com
Convert to use new apis in following sysfs apis:
- level_store
- suspend_lo_store
- suspend_hi_store
- serialize_policy_store
These are not hot path, so performance is not concerned.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-11-yukuai1@huaweicloud.com
Advantages for new apis:
- reconfig_mutex is not required;
- the weird logical that suspend array hold 'reconfig_mutex' for
mddev_check_recovery() to update superblock is not needed;
- the specail handling, 'pers->prepare_suspend', for raid456 is not
needed;
- It's safe to be called at any time once mddev is allocated, and it's
designed to be used from slow path where array configuration is changed;
- the new helpers is designed to be called before mddev_lock(), hence
it support to be interrupted by user as well.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-5-yukuai1@huaweicloud.com
Prepare to cleanup pers->prepare_suspend(), which is used to fix a
deadlock in raid456 by returning error for io that is waiting for
reshape to make progress in mddev_suspend().
This change will allow reshape to make progress while waiting for io to
be done in mddev_suspend() in following patches.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20231010151958.145896-4-yukuai1@huaweicloud.com
We don't need to lock device to reject not supported request
in array_state_store(). No functional changes intended.
There are differences between ioctl and sysfs handling during stopping.
With this change, it will be easier to add additional steps which needs
to be completed before mddev_lock() is taken.
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230928125517.12356-1-mariusz.tkaczyk@linux.intel.com
Before this patch, the implementation is hacky and hard to understand:
1) md_seq_start set pos to 1;
2) md_seq_show found pos is 1, then print Personalities;
3) md_seq_next found pos is 1, then it update pos to the first mddev;
4) md_seq_show found pos is not 1 or 2, show mddev;
5) md_seq_next found pos is not 1 or 2, update pos to next mddev;
6) loop 4-5 until the last mddev, then md_seq_next update pos to 2;
7) md_seq_show found pos is 2, then print unused devices;
8) md_seq_next found pos is 2, stop;
This patch remove the magic value and use seq_list_start/next/stop()
directly, and move printing "Personalities" to md_seq_start(),
"unsed devices" to md_seq_stop():
1) md_seq_start print Personalities, and then set pos to first mddev;
2) md_seq_show show mddev;
3) md_seq_next update pos to next mddev;
4) loop 2-3 until the last mddev;
5) md_seq_stop print unsed devices;
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230927061241.1552837-3-yukuai1@huaweicloud.com
`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
There are three such strncpy uses that this patch addresses:
The respective destination buffers are:
1) mddev->clevel
2) clevel
3) mddev->metadata_type
We expect mddev->clevel to be NUL-terminated due to its use with format
strings:
| ret = sprintf(page, "%s\n", mddev->clevel);
Furthermore, we can see that mddev->clevel is not expected to be
NUL-padded as `md_clean()` merely set's its first byte to NULL -- not
the entire buffer:
| static void md_clean(struct mddev *mddev)
| {
| mddev->array_sectors = 0;
| mddev->external_size = 0;
| ...
| mddev->level = LEVEL_NONE;
| mddev->clevel[0] = 0;
| ...
A suitable replacement for this instance is `memcpy` as we know the
number of bytes to copy and perform manual NUL-termination at a
specified offset. This really decays to just a byte copy from one buffer
to another. `strscpy` is also a considerable replacement but using
`slen` as the length argument would result in truncation of the last
byte unless something like `slen + 1` was provided which isn't the most
idiomatic strscpy usage.
For the next case, the destination buffer `clevel` is expected to be
NUL-terminated based on its usage within kstrtol() which expects
NUL-terminated strings. Note that, in context, this code removes a
trailing newline which is seemingly not required as kstrtol() can handle
trailing newlines implicitly. However, there exists further usage of
clevel (or buf) that would also like to have the newline removed. All in
all, with similar reasoning to the first case, let's just use memcpy as
this is just a byte copy and NUL-termination is handled manually.
The third and final case concerning `mddev->metadata_type` is more or
less the same as the other two. We expect that it be NUL-terminated
based on its usage with seq_printf:
| seq_printf(seq, " super external:%s",
| mddev->metadata_type);
... and we can surmise that NUL-padding isn't required either due to how
it is handled in md_clean():
| static void md_clean(struct mddev *mddev)
| {
| ...
| mddev->metadata_type[0] = 0;
| ...
So really, all these instances have precisely calculated lengths and
purposeful NUL-termination so we can just use memcpy to remove ambiguity
surrounding strncpy.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230925-strncpy-drivers-md-md-c-v1-1-2b0093b89c2b@google.com
Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's
safe to remove such checking.
This will also allow the array to be suspended even before the array
is ran.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-8-yukuai1@huaweicloud.com
Now that mddev_suspend() doean't rely on 'mddev->pers' to be set, it's
safe to remove such checking.
This will also allow the array to be suspended even before the array
is ran.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-7-yukuai1@huaweicloud.com
'active_io' used to be initialized while the array is running, and
'mddev->pers' is set while the array is running as well. Hence caller
must hold 'reconfig_mutex' and guarantee 'mddev->pers' is set before
calling mddev_suspend().
Now that 'active_io' is initialized when mddev is allocated, such
restriction doesn't exist anymore. In the meantime, follow up patches
will refactor mddev_suspend(), hence add checking for 'mddev->pers' to
prevent null-ptr-deref.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-4-yukuai1@huaweicloud.com
Currently 'writes_pending' is initialized in pers->run for raid1/5/10,
and it's freed while deleing mddev, instead of pers->free. pers->run can
be called multiple times before mddev is deleted, and a helper
mddev_init_writes_pending() is used to prevent 'writes_pending' to be
initialized multiple times, this usage is safe but a litter weird.
On the other hand, 'writes_pending' is only initialized for raid1/5/10,
however, it's used in common layer, for example:
array_state_store
set_in_sync
if (!mddev->in_sync) -> in_sync is used for all levels
// access writes_pending
There might be some implicit dependency that I don't recognized to make
sure 'writes_pending' can only be accessed for raid1/5/10, but there are
no comments about that.
By the way, it make sense to initialize 'writes_pending' in common layer
because there are already three levels use it.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-3-yukuai1@huaweicloud.com
'active_io' is used for mddev_suspend() and it's initialized in
md_run(), this restrict that 'reconfig_mutex' must be held and
"mddev->pers" must be set before calling mddev_suspend().
Initialize 'active_io' early so that mddev_suspend() is safe to call
once mddev is allocated, this will be helpful to refactor
mddev_suspend() in following patches.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825030956.1527023-2-yukuai1@huaweicloud.com
Before this patch, for read-only array:
md_check_recovery() check that 'MD_RECOVERY_NEEDED' is set, then it will
call remove_and_add_spares() directly to try to remove and add rdevs
from array.
After this patch:
1) md_check_recovery() check that 'MD_RECOVERY_NEEDED' is set, and the
worker 'sync_work' is not pending, and there are rdevs can be added
or removed, then it will queue new work md_start_sync();
2) md_start_sync() will call remove_and_add_spares() and exist;
This change make sure that array reconfiguration is independent from
daemon, and it'll be much easier to synchronize it with io, consier
that io may rely on daemon thread to be done.
Also fix a problem that 'pers->spars_active' is called after
remove_and_add_spares(), which order is wrong, because spares must
active first, and then remove_and_add_spares() can add spares to the
array, like what read-write case does:
1) daemon set 'MD_RECOVERY_RUNNING', register new sync thread to do
recovery;
2) recovery is done, md_do_sync() set 'MD_RECOVERY_DONE' before return;
3) daemon call 'pers->spars_active', and clear 'MD_RECOVERY_RUNNING';
4) in the next round of daemon, call remove_and_add_spares() to add
spares to the array.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230825031622.1530464-8-yukuai1@huaweicloud.com
Linus Torvalds