It's no longer used and can be removed, also remove the field
'gendisk->sync_io'.

Link: https://lore.kernel.org/linux-raid/20250506124903.2540268-10-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.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>

Following patch will use gendisk to check if there are normal IO
completed or inflight, to fix a problem in mdraid that foreground IO
can be starved by background sync IO in later patches.

Link: https://lore.kernel.org/linux-raid/20250506124903.2540268-7-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: 9e0e252a048b ("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>

To make code cleaner, and prepare to add kconfig for bitmap.

Also remove the unsed global variables pers_lock, md_cluster_ops and
md_cluster_mod, and exported symbols register_md_cluster_operations(),
unregister_md_cluster_operations() and md_cluster_ops.

Link: https://lore.kernel.org/linux-raid/20250215092225.2427977-8-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Su Yue <glass.su@suse.com>

Add a new field 'cluster_ops' and initialize it md_setup_cluster(), so
that the gloable variable 'md_cluter_ops' doesn't need to be exported.
Also prepare to switch md-cluster to use md_submod_head.

Link: https://lore.kernel.org/linux-raid/20250215092225.2427977-7-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Su Yue <glass.su@suse.com>

Remove the global list 'pers_list', and switch to use md_submodule_head,
which is managed by xarry. Prepare to unify registration and unregistration
for all sub modules.

Link: https://lore.kernel.org/linux-raid/20250215092225.2427977-5-yukuai1@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai3@huawei.com>