Hi,
在 2024/02/20 23:30, Xiao Ni 写道:
stripe_ahead_of_reshape is used to check if a stripe region cross the
reshape position. So first, change the function name to
stripe_across_reshape to describe the usage of this function.
For reshape backwards, it starts reshape from the end of array and conf->
reshape_progress is init to raid5_size. During reshape, if previous is true
(set in make_stripe_request) and max_sector >= conf->reshape_progress, ios
should wait until reshape window moves forward. But ios don't need to wait
if max_sector is raid5_size.
And put the conditions into the function directly to make understand the
codes easily.
This can be reproduced easily by lvm2 test shell/lvconvert-raid-reshape.sh
For dm raid reshape, before starting sync thread, it needs to reload table
some times. In one time dm raid uses MD_RECOVERY_WAIT to delay reshape and
it doesn't start sync thread this time. Then one io comes in and it waits
because stripe_ahead_of_reshape returns true because it's a backward
reshape and max_sectors > conf->reshape_progress. But the reshape hasn't
started. So skip this check when reshape_progress is raid5_size
Like I said before, after following merged patch:
ad39c08186f8 md: Don't register sync_thread for reshape directly
You should not see that sync_thread fo reshape is registered while
MD_RECOVERY_WAIT is set, so this patch should not be needed.
Thanks,
Kuai
Fixes: 486f60558607 ("md/raid5: Check all disks in a stripe_head for reshape progress")
Signed-off-by: Xiao Ni <xni@xxxxxxxxxx>
---
drivers/md/raid5.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 8497880135ee..4c71df4e2370 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5832,17 +5832,12 @@ static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
sector >= reshape_sector;
}
-static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
- sector_t max, sector_t reshape_sector)
-{
- return mddev->reshape_backwards ? max < reshape_sector :
- min >= reshape_sector;
-}
-
-static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
+static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
+static bool stripe_across_reshape(struct mddev *mddev, struct r5conf *conf,
struct stripe_head *sh)
{
sector_t max_sector = 0, min_sector = MaxSector;
+ sector_t reshape_pos = 0;
bool ret = false;
int dd_idx;
@@ -5856,9 +5851,12 @@ static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
spin_lock_irq(&conf->device_lock);
- if (!range_ahead_of_reshape(mddev, min_sector, max_sector,
- conf->reshape_progress))
- /* mismatch, need to try again */
+ reshape_pos = conf->reshape_progress;
+ if (mddev->reshape_backwards) {
+ if (max_sector >= reshape_pos &&
+ reshape_pos != raid5_size(mddev, 0, 0))
+ ret = true;
+ } else if (min_sector < reshape_pos)
ret = true;
spin_unlock_irq(&conf->device_lock);
@@ -5969,7 +5967,7 @@ static enum stripe_result make_stripe_request(struct mddev *mddev,
}
if (unlikely(previous) &&
- stripe_ahead_of_reshape(mddev, conf, sh)) {
+ stripe_across_reshape(mddev, conf, sh)) {
/*
* Expansion moved on while waiting for a stripe.
* Expansion could still move past after this
