diff options
| author | NeilBrown <neilb@suse.com> | 2015-07-24 13:30:32 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.com> | 2015-08-31 19:38:59 +0200 |
| commit | 6cbd81487f7cfa30e22537bf7cd07f48c4e7164d (patch) | |
| tree | 65d510b83cb87211dd53c636fe54c414df3015bd /drivers | |
| parent | 5ed1df2eacc0ba92c8c7e2499c97594b5ef928a8 (diff) | |
md/raid5: handle possible race as reshape completes.
It is possible (though unlikely) for a reshape to be
interrupted between the time that end_reshape is called
and the time when raid5_finish_reshape is called.
This can leave conf->reshape_progress set to MaxSector,
but mddev->reshape_position not.
This combination confused reshape_request() when ->reshape_backwards.
As conf->reshape_progress is so high, it seems the reshape hasn't
really begun. But assuming MaxSector is a valid address only
leads to sorrow.
So ensure reshape_position and reshape_progress both agree,
and add an extra check in reshape_request() just in case they don't.
Signed-off-by: NeilBrown <neilb@suse.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/raid5.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 1c27aa10f89c..7b0c706f33e7 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5355,6 +5355,10 @@ static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *sk conf->reshape_progress < raid5_size(mddev, 0, 0)) { sector_nr = raid5_size(mddev, 0, 0) - conf->reshape_progress; + } else if (mddev->reshape_backwards && + conf->reshape_progress == MaxSector) { + /* shouldn't happen, but just in case, finish up.*/ + sector_nr = MaxSector; } else if (!mddev->reshape_backwards && conf->reshape_progress > 0) sector_nr = conf->reshape_progress; @@ -7446,6 +7450,7 @@ static void end_reshape(struct r5conf *conf) rdev->data_offset = rdev->new_data_offset; smp_wmb(); conf->reshape_progress = MaxSector; + conf->mddev->reshape_position = MaxSector; spin_unlock_irq(&conf->device_lock); wake_up(&conf->wait_for_overlap); |