Previously, using wait_event() would wake up all waiters simultaneously,
and they would compete for the tree lock. The bio which gets the lock
first will be handled, so the write sequence cannot be guaranteed.
For example:
bio1(100,200)
bio2(150,200)
bio3(150,300)
The write sequence of fast device is bio1,bio2,bio3. But the write sequence
of slow device could be bio1,bio3,bio2 due to lock competition. This causes
data corruption.
Replace waitqueue with a fifo list to guarantee the write sequence. And it
also needs to iterate the list when removing one entry. If not, it may miss
the opportunity to wake up the waiting io.
For example:
bio1(1,3), bio2(2,4)
bio3(5,7), bio4(6,8)
These four bios are in the same bucket. bio1 and bio3 are inserted into
the rbtree. bio2 and bio4 are added to the waiting list and bio2 is the
first one. bio3 returns from slow disk and tries to wake up the waiting
bios. bio2 is removed from the list and will be handled. But bio1 hasn't
finished. So bio2 will be added into waiting list again. Then bio1 returns
from slow disk and wakes up waiting bios. bio4 is removed from the list
and will be handled. Now bio1, bio3 and bio4 all finish and bio2 is left
on the waiting list. So it needs to iterate the waiting list to wake up
the right bio.
Signed-off-by: Xiao Ni <xni@redhat.com>
Link: https://lore.kernel.org/linux-raid/20260324072501.59865-1-xni@redhat.com/
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
'recovery_disabled' logic is complex and confusing, originally intended to
preserve raid in extreme scenarios. It was used in following cases:
- When sync fails and setting badblocks also fails, kick out non-In_sync
rdev and block spare rdev from joining to preserve raid [1]
- When last backup is unavailable, prevent repeated add-remove of spares
triggering recovery [2]
The original issues are now resolved:
- Error handlers in all raid types prevent last rdev from being kicked out
- Disks with failed recovery are marked Faulty and can't re-join
Therefore, remove 'recovery_disabled' as it's no longer needed.
[1] 5389042ffa ("md: change managed of recovery_disabled.")
[2] 4044ba58dd ("md: don't retry recovery of raid1 that fails due to error on source drive.")
Link: https://lore.kernel.org/linux-raid/20260105110300.1442509-13-linan666@huaweicloud.com
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
On the one hand, stripe_request_ctx is 72 bytes, and it's a bit huge for
a stack variable.
On the other hand, the bitmap sectors_to_do is a fixed size, result in
max_hw_sector_kb of raid5 array is at most 256 * 4k = 1Mb, and this will
make full stripe IO impossible for the array that chunk_size * data_disks
is bigger. Allocate ctx during runtime will make it possible to get rid
of this limit.
Link: https://lore.kernel.org/linux-raid/20260114171241.3043364-6-yukuai@fnnas.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Previously, raid array used the maximum logical block size (LBS)
of all member disks. Adding a larger LBS disk at runtime could
unexpectedly increase RAID's LBS, risking corruption of existing
partitions. This can be reproduced by:
```
# LBS of sd[de] is 512 bytes, sdf is 4096 bytes.
mdadm -CRq /dev/md0 -l1 -n3 /dev/sd[de] missing --assume-clean
# LBS is 512
cat /sys/block/md0/queue/logical_block_size
# create partition md0p1
parted -s /dev/md0 mklabel gpt mkpart primary 1MiB 100%
lsblk | grep md0p1
# LBS becomes 4096 after adding sdf
mdadm --add -q /dev/md0 /dev/sdf
cat /sys/block/md0/queue/logical_block_size
# partition lost
partprobe /dev/md0
lsblk | grep md0p1
```
Simply restricting larger-LBS disks is inflexible. In some scenarios,
only disks with 512 bytes LBS are available currently, but later, disks
with 4KB LBS may be added to the array.
Making LBS configurable is the best way to solve this scenario.
After this patch, the raid will:
- store LBS in disk metadata
- add a read-write sysfs 'mdX/logical_block_size'
Future mdadm should support setting LBS via metadata field during RAID
creation and the new sysfs. Though the kernel allows runtime LBS changes,
users should avoid modifying it after creating partitions or filesystems
to prevent compatibility issues.
Only 1.x metadata supports configurable LBS. 0.90 metadata inits all
fields to default values at auto-detect. Supporting 0.90 would require
more extensive changes and no such use case has been observed.
Note that many RAID paths rely on PAGE_SIZE alignment, including for
metadata I/O. A larger LBS than PAGE_SIZE will result in metadata
read/write failures. So this config should be prevented.
Link: https://lore.kernel.org/linux-raid/20251103125757.1405796-6-linan666@huaweicloud.com
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
There is a uaf problem which is found by case 23rdev-lifetime:
Oops: general protection fault, probably for non-canonical address 0xdead000000000122
RIP: 0010:bdi_unregister+0x4b/0x170
Call Trace:
<TASK>
__del_gendisk+0x356/0x3e0
mddev_unlock+0x351/0x360
rdev_attr_store+0x217/0x280
kernfs_fop_write_iter+0x14a/0x210
vfs_write+0x29e/0x550
ksys_write+0x74/0xf0
do_syscall_64+0xbb/0x380
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff5250a177e
The sequence is:
1. rdev remove path gets reconfig_mutex
2. rdev remove path release reconfig_mutex in mddev_unlock
3. md stop calls do_md_stop and sets MD_DELETED
4. rdev remove path calls del_gendisk because MD_DELETED is set
5. md stop path release reconfig_mutex and calls del_gendisk again
So there is a race condition we should resolve. This patch adds a
flag MD_DO_DELETE to avoid the race condition.
Link: https://lore.kernel.org/linux-raid/20251029063419.21700-1-xni@redhat.com
Fixes: 9e59d60976 ("md: call del_gendisk in control path")
Signed-off-by: Xiao Ni <xni@redhat.com>
Suggested-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Redundant data is used to enhance data fault tolerance, and the storage
method for redundant data vary depending on the RAID levels. And it's
important to maintain the consistency of redundant data.
Bitmap is used to record which data blocks have been synchronized and which
ones need to be resynchronized or recovered. Each bit in the bitmap
represents a segment of data in the array. When a bit is set, it indicates
that the multiple redundant copies of that data segment may not be
consistent. Data synchronization can be performed based on the bitmap after
power failure or readding a disk. If there is no bitmap, a full disk
synchronization is required.
Due to known performance issues with md-bitmap and the unreasonable
implementations:
- self-managed IO submitting like filemap_write_page();
- global spin_lock
I have decided not to continue optimizing based on the current bitmap
implementation, this new bitmap is invented without locking from IO fast
path and can be used with fast disks.
For designs and details, see the comments in drivers/md-llbitmap.c.
Link: https://lore.kernel.org/linux-raid/20250829080426.1441678-12-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Now del_gendisk and put_disk are called asynchronously in workqueue work.
The asynchronous way has a problem that the device node can still exist
after mdadm --stop command returns in a short window. So udev rule can
open this device node and create the struct mddev in kernel again. So put
del_gendisk in control path and still leave put_disk in md_kobj_release
to avoid uaf of gendisk.
Function del_gendisk can't be called with reconfig_mutex. If it's called
with reconfig mutex, a deadlock can happen. del_gendisk waits all sysfs
files access to finish and sysfs file access waits reconfig mutex. So
put del_gendisk after releasing reconfig mutex.
But there is still a window that sysfs can be accessed between mddev_unlock
and del_gendisk. So some actions (add disk, change level, .e.g) can happen
which lead unexpected results. MD_DELETED is used to resolve this problem.
MD_DELETED is set before releasing reconfig mutex and it should be checked
for these sysfs access which need reconfig mutex. For sysfs access which
don't need reconfig mutex, del_gendisk will wait them to finish.
But it doesn't need to do this in function mddev_lock_nointr. There are
ten places that call it.
* Five of them are in dm raid which we don't need to care. MD_DELETED is
only used for md raid.
* stop_sync_thread, md_do_sync and md_start_sync are related sync request,
and it needs to wait sync thread to finish before stopping an array.
* md_ioctl: md_open is called before md_ioctl, so ->openers is added. It
will fail to stop the array. So it doesn't need to check MD_DELETED here
* md_set_readonly:
It needs to call mddev_set_closing_and_sync_blockdev when setting readonly
or read_auto. So it will fail to stop the array too because MD_CLOSING is
already set.
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Link: https://lore.kernel.org/linux-raid/20250611073108.25463-2-xni@redhat.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
If sync_speed is above speed_min, then is_mddev_idle() will be called
for each sync IO to check if the array is idle, and inflight sync_io
will be limited if the array is not idle.
However, while mkfs.ext4 for a large raid5 array while recovery is in
progress, it's found that sync_speed is already above speed_min while
lots of stripes are used for sync IO, causing long delay for mkfs.ext4.
Root cause is the following checking from is_mddev_idle():
t1: submit sync IO: events1 = completed IO - issued sync IO
t2: submit next sync IO: events2 = completed IO - issued sync IO
if (events2 - events1 > 64)
For consequence, the more sync IO issued, the less likely checking will
pass. And when completed normal IO is more than issued sync IO, the
condition will finally pass and is_mddev_idle() will return false,
however, last_events will be updated hence is_mddev_idle() can only
return false once in a while.
Fix this problem by changing the checking as following:
1) mddev doesn't have normal IO completed;
2) mddev doesn't have normal IO inflight;
3) if any member disks is partition, and all other partitions doesn't
have IO completed.
Also change rdev->last_events to unsigned long to cleanup type casting.
Link: https://lore.kernel.org/linux-raid/20250506124903.2540268-9-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Currently if sync speed is above speed_min and below speed_max,
md_do_sync() will wait for all sync IOs to be done before issuing new
sync IO, means sync IO depth is limited to just 1.
This limit is too low, in order to prevent sync speed drop conspicuously
after fixing is_mddev_idle() in the next patch, add a new api for
limiting sync IO depth, the default value is 32.
Link: https://lore.kernel.org/linux-raid/20250506124903.2540268-8-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Merge MD changes from Yu:
"- fix recovery can preempt resync (Li Nan)
- fix md-bitmap IO limit (Su Yue)
- fix raid10 discard with REQ_NOWAIT (Xiao Ni)
- fix raid1 memory leak (Zheng Qixing)
- fix mddev uaf (Yu Kuai)
- fix raid1,raid10 IO flags (Yu Kuai)
- some refactor and cleanup (Yu Kuai)"
* tag 'md-6.15-20250312' of https://git.kernel.org/pub/scm/linux/kernel/git/mdraid/linux:
md/raid10: wait barrier before returning discard request with REQ_NOWAIT
md/md-bitmap: fix wrong bitmap_limit for clustermd when write sb
md/raid1,raid10: don't ignore IO flags
md/raid5: merge reshape_progress checking inside get_reshape_loc()
md: fix mddev uaf while iterating all_mddevs list
md: switch md-cluster to use md_submodle_head
md: don't export md_cluster_ops
md/md-cluster: cleanup md_cluster_ops reference
md: switch personalities to use md_submodule_head
md: introduce struct md_submodule_head and APIs
md: only include md-cluster.h if necessary
md: merge common code into find_pers()
md/raid1: fix memory leak in raid1_run() if no active rdev
md: ensure resync is prioritized over recovery
There is a truncation of badblocks length issue when set badblocks as
follow:
echo "2055 4294967299" > bad_blocks
cat bad_blocks
2055 3
Change 'sectors' argument type from 'int' to 'sector_t'.
This change avoids truncation of badblocks length for large sectors by
replacing 'int' with 'sector_t' (u64), enabling proper handling of larger
disk sizes and ensuring compatibility with 64-bit sector addressing.
Fixes: 9e0e252a04 ("badblocks: Add core badblock management code")
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Acked-by: Coly Li <colyli@kernel.org>
Link: https://lore.kernel.org/r/20250227075507.151331-13-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
rdev_set_badblocks() only indicates success/failure, so convert its return
type from int to boolean for better semantic clarity.
rdev_clear_badblocks() return value is never used by any caller, convert it
to void. This removes unnecessary value returns.
Also update narrow_write_error() in both raid1 and raid10 to use boolean
return type to match rdev_set_badblocks().
Signed-off-by: Zheng Qixing <zhengqixing@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250227075507.151331-12-zhengqixing@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There are two BUG reports that raid5 will hang at
bitmap_startwrite([1],[2]), root cause is that bitmap start write and end
write is unbalanced, it's not quite clear where, and while reviewing raid5
code, it's found that bitmap operations can be optimized. For example,
for a 4 disks raid5, with chunksize=8k, if user issue a IO (0 + 48k) to
the array:
┌────────────────────────────────────────────────────────────┐
│chunk 0 │
│ ┌────────────┬─────────────┬─────────────┬────────────┼
│ sh0 │A0: 0 + 4k │A1: 8k + 4k │A2: 16k + 4k │A3: P │
│ ┼────────────┼─────────────┼─────────────┼────────────┼
│ sh1 │B0: 4k + 4k │B1: 12k + 4k │B2: 20k + 4k │B3: P │
┼──────┴────────────┴─────────────┴─────────────┴────────────┼
│chunk 1 │
│ ┌────────────┬─────────────┬─────────────┬────────────┤
│ sh2 │C0: 24k + 4k│C1: 32k + 4k │C2: P │C3: 40k + 4k│
│ ┼────────────┼─────────────┼─────────────┼────────────┼
│ sh3 │D0: 28k + 4k│D1: 36k + 4k │D2: P │D3: 44k + 4k│
└──────┴────────────┴─────────────┴─────────────┴────────────┘
Before this patch, 4 stripe head will be used, and each sh will attach
bio for 3 disks, and each attached bio will trigger
bitmap_startwrite() once, which means total 12 times.
- 3 times (0 + 4k), for (A0, A1 and A2)
- 3 times (4 + 4k), for (B0, B1 and B2)
- 3 times (8 + 4k), for (C0, C1 and C3)
- 3 times (12 + 4k), for (D0, D1 and D3)
After this patch, md upper layer will calculate that IO range (0 + 48k)
is corresponding to the bitmap (0 + 16k), and call bitmap_startwrite()
just once.
Noted that this patch will align bitmap ranges to the chunks, for example,
if user issue a IO (0 + 4k) to array:
- Before this patch, 1 time (0 + 4k), for A0;
- After this patch, 1 time (0 + 8k) for chunk 0;
Usually, one bitmap bit will represent more than one disk chunk, and this
doesn't have any difference. And even if user really created a array
that one chunk contain multiple bits, the overhead is that more data
will be recovered after power failure.
Also remove STRIPE_BITMAP_PENDING since it's not used anymore.
[1] https://lore.kernel.org/all/CAJpMwyjmHQLvm6zg1cmQErttNNQPDAAXPKM3xgTjMhbfts986Q@mail.gmail.com/
[2] https://lore.kernel.org/all/ADF7D720-5764-4AF3-B68E-1845988737AA@flyingcircus.io/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20250109015145.158868-6-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
From Yu Kuai (with minor changes by Song Liu):
The background is that currently bitmap is using a global spin_lock,
causing lock contention and huge IO performance degradation for all raid
levels.
However, it's impossible to implement a new lock free bitmap with
current situation that md-bitmap exposes the internal implementation
with lots of exported apis. Hence bitmap_operations is invented, to
describe bitmap core implementation, and a new bitmap can be introduced
with a new bitmap_operations, we only need to switch to the new one
during initialization.
And with this we can build bitmap as kernel module, but that's not
our concern for now.
This version was tested with mdadm tests and lvm2 tests. This set does
not introduce new errors in these tests.
* md-6.12-bitmap: (42 commits)
md/md-bitmap: make in memory structure internal
md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations
md/md-bitmap: merge md_bitmap_wait_behind_writes() into bitmap_operations
md/md-bitmap: merge md_bitmap_free() into bitmap_operations
md/md-bitmap: merge md_bitmap_set_pages() into struct bitmap_operations
md/md-bitmap: merge md_bitmap_copy_from_slot() into struct bitmap_operation.
md/md-bitmap: merge get_bitmap_from_slot() into bitmap_operations
md/md-bitmap: merge md_bitmap_resize() into bitmap_operations
md/md-bitmap: pass in mddev directly for md_bitmap_resize()
md/md-bitmap: merge md_bitmap_daemon_work() into bitmap_operations
md/md-bitmap: merge bitmap_unplug() into bitmap_operations
md/md-bitmap: merge md_bitmap_unplug_async() into md_bitmap_unplug()
md/md-bitmap: merge md_bitmap_sync_with_cluster() into bitmap_operations
md/md-bitmap: merge md_bitmap_cond_end_sync() into bitmap_operations
md/md-bitmap: merge md_bitmap_close_sync() into bitmap_operations
md/md-bitmap: merge md_bitmap_end_sync() into bitmap_operations
md/md-bitmap: remove the parameter 'aborted' for md_bitmap_end_sync()
md/md-bitmap: merge md_bitmap_start_sync() into bitmap_operations
md/md-bitmap: merge md_bitmap_endwrite() into bitmap_operations
md/md-bitmap: merge md_bitmap_startwrite() into bitmap_operations
...
Signed-off-by: Song Liu <song@kernel.org>
For flush request, md has a special flush handling to merge concurrent
flush request into single one, however, the whole mechanism is based on
a disk level spin_lock 'mddev->lock'. And fsync can be called quite
often in some user cases, for consequence, spin lock from IO fast path can
cause performance degradation.
Fortunately, the block layer already has flush handling to merge
concurrent flush request, and it only acquires hctx level spin lock. (see
details in blk-flush.c)
This patch removes the flush handling in md, and converts to use general
block layer flush handling in underlying disks.
Flush test for 4 nvme raid10:
start 128 threads to do fsync 100000 times, on arm64, see how long it
takes.
Test script:
void* thread_func(void* arg) {
int fd = *(int*)arg;
for (int i = 0; i < FSYNC_COUNT; i++) {
fsync(fd);
}
return NULL;
}
int main() {
int fd = open("/dev/md0", O_RDWR);
if (fd < 0) {
perror("open");
exit(1);
}
pthread_t threads[THREADS];
struct timeval start, end;
gettimeofday(&start, NULL);
for (int i = 0; i < THREADS; i++) {
pthread_create(&threads[i], NULL, thread_func, &fd);
}
for (int i = 0; i < THREADS; i++) {
pthread_join(threads[i], NULL);
}
gettimeofday(&end, NULL);
close(fd);
long long elapsed = (end.tv_sec - start.tv_sec) * 1000000LL + (end.tv_usec - start.tv_usec);
printf("Elapsed time: %lld microseconds\n", elapsed);
return 0;
}
Test result: about 10 times faster:
Before this patch: 50943374 microseconds
After this patch: 5096347 microseconds
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240827110616.3860190-1-yukuai1@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
'struct md_cluster_operations' is not modified in this driver.
Constifying this structure moves some data to a read-only section, so
increase overall security.
On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
51941 1442 80 53463 d0d7 drivers/md/md-cluster.o
After:
=====
text data bss dec hex filename
52133 1246 80 53459 d0d3 drivers/md/md-cluster.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/3727f3ce9693cae4e62ae6778ea13971df805479.1719173852.git.christophe.jaillet@wanadoo.fr
The md driver wants to enforce a number of flags for all devices, even
when not inheriting them from the underlying devices. To make sure these
flags survive the queue_limits_set calls that md uses to update the
queue limits without deriving them form the previous limits add a new
md_init_stacking_limits helper that calls blk_set_stacking_limits and sets
these flags.
Fixes: 1122c0c1cc ("block: move cache control settings out of queue->flags")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240626142637.300624-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull in block limits branch, which exists as a shared branch for both
the block and SCSI tree.
* for-6.11/block-limits: (26 commits)
block: move integrity information into queue_limits
block: invert the BLK_INTEGRITY_{GENERATE,VERIFY} flags
block: bypass the STABLE_WRITES flag for protection information
block: don't require stable pages for non-PI metadata
block: use kstrtoul in flag_store
block: factor out flag_{store,show} helper for integrity
block: remove the blk_flush_integrity call in blk_integrity_unregister
block: remove the blk_integrity_profile structure
dm-integrity: use the nop integrity profile
md/raid1: don't free conf on raid0_run failure
md/raid0: don't free conf on raid0_run failure
block: initialize integrity buffer to zero before writing it to media
block: add special APIs for run-time disabling of discard and friends
block: remove unused queue limits API
sr: convert to the atomic queue limits API
sd: convert to the atomic queue limits API
sd: cleanup zoned queue limits initialization
sd: factor out a sd_discard_mode helper
sd: simplify the disable case in sd_config_discard
sd: add a sd_disable_write_same helper
...
Move the integrity information into the queue limits so that it can be
set atomically with other queue limits, and that the sysfs changes to
the read_verify and write_generate flags are properly synchronized.
This also allows to provide a more useful helper to stack the integrity
fields, although it still is separate from the main stacking function
as not all stackable devices want to inherit the integrity settings.
Even with that it greatly simplifies the code in md and dm.
Note that the integrity field is moved as-is into the queue limits.
While there are good arguments for removing the separate blk_integrity
structure, this would cause a lot of churn and might better be done at a
later time if desired. However the integrity field in the queue_limits
structure is now unconditional so that various ifdefs can be avoided or
replaced with IS_ENABLED(). Given that tiny size of it that seems like
a worthwhile trade off.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For different sync_action, sync_thread will use different max_sectors,
see details in md_sync_max_sectors(), currently both md_do_sync() and
pers->sync_request() in eatch iteration have to get the same
max_sectors. Hence pass in max_sectors for pers->sync_request() to
prevent redundant code.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240611132251.1967786-12-yukuai1@huaweicloud.com
The only difference is that "none" is removed and initial
last_sync_action will be idle.
On the one hand, this value is introduced by commit c4a3955145
("MD: Remember the last sync operation that was performed"), and the
usage described in commit message is not affected. On the other hand,
last_sync_action is not used in mdadm or mdmon, and none of the tests
that I can find.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240611132251.1967786-10-yukuai1@huaweicloud.com
MD_RECOVERY_RUNNING will always be set when trying to register a new
sync_thread, however, if md_start_sync() turns out to do nothing,
MD_RECOVERY_RUNNING will be cleared in this case. And during the race
window, action_store() will return -EBUSY, which will cause some
mdadm tests to fail. For example:
The test 07reshape5intr will add a new disk to array, then start
reshape:
mdadm /dev/md0 --add /dev/xxx
mdadm --grow /dev/md0 -n 3
And add_bound_rdev() from mdadm --add will set MD_RECOVERY_NEEDED,
then during the race windown, mdadm --grow will fail.
Fix the problem by waiting in action_store() during the race window,
fail only if sync_thread is registered.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240611132251.1967786-8-yukuai1@huaweicloud.com
