md: fix soft lockup in status_resync
status_resync() will calculate 'curr_resync - recovery_active' to show user a progress bar like following: [============>........] resync = 61.4% 'curr_resync' and 'recovery_active' is updated in md_do_sync(), and status_resync() can read them concurrently, hence it's possible that 'curr_resync - recovery_active' can overflow to a huge number. In this case status_resync() will be stuck in the loop to print a large amount of '=', which will end up soft lockup. Fix the problem by setting 'resync' to MD_RESYNC_ACTIVE in this case, this way resync in progress will be reported to user. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Signed-off-by: Song Liu <song@kernel.org> Link: https://lore.kernel.org/r/20230310073855.1337560-3-yukuai1@huaweicloud.com
This commit is contained in:
parent
c31fea2f8e
commit
6efddf1e32
@ -8032,16 +8032,16 @@ static int status_resync(struct seq_file *seq, struct mddev *mddev)
|
|||||||
} else if (resync > max_sectors) {
|
} else if (resync > max_sectors) {
|
||||||
resync = max_sectors;
|
resync = max_sectors;
|
||||||
} else {
|
} else {
|
||||||
resync -= atomic_read(&mddev->recovery_active);
|
res = atomic_read(&mddev->recovery_active);
|
||||||
if (resync < MD_RESYNC_ACTIVE) {
|
/*
|
||||||
/*
|
* Resync has started, but the subtraction has overflowed or
|
||||||
* Resync has started, but the subtraction has
|
* yielded one of the special values. Force it to active to
|
||||||
* yielded one of the special values. Force it
|
* ensure the status reports an active resync.
|
||||||
* to active to ensure the status reports an
|
*/
|
||||||
* active resync.
|
if (resync < res || resync - res < MD_RESYNC_ACTIVE)
|
||||||
*/
|
|
||||||
resync = MD_RESYNC_ACTIVE;
|
resync = MD_RESYNC_ACTIVE;
|
||||||
}
|
else
|
||||||
|
resync -= res;
|
||||||
}
|
}
|
||||||
|
|
||||||
if (resync == MD_RESYNC_NONE) {
|
if (resync == MD_RESYNC_NONE) {
|
||||||
|
Loading…
Reference in New Issue
Block a user