diff options
| author | Shaohua Li <shli@fb.com> | 2016-02-24 17:38:28 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-12 09:08:57 -0700 |
| commit | 8568767fe1d63fbbdeacf2f69da6f84ad277d4f7 (patch) | |
| tree | 630aeb7c27e18aa69a40bc1b5e10c9a07cbf1572 /drivers/md | |
| parent | fad8b6fc040bf1d9807ee0e3358275d06b14cf96 (diff) | |
RAID5: check_reshape() shouldn't call mddev_suspend
commit 27a353c026a879a1001e5eac4bda75b16262c44a upstream.
check_reshape() is called from raid5d thread. raid5d thread shouldn't
call mddev_suspend(), because mddev_suspend() waits for all IO finish
but IO is handled in raid5d thread, we could easily deadlock here.
This issue is introduced by
738a273 ("md/raid5: fix allocation of 'scribble' array.")
Reported-and-tested-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/raid5.c | 18 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 2 |
2 files changed, 20 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index c13921adec93..d3e747cd0b34 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2091,6 +2091,14 @@ static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors) unsigned long cpu; int err = 0; + /* + * Never shrink. And mddev_suspend() could deadlock if this is called + * from raid5d. In that case, scribble_disks and scribble_sectors + * should equal to new_disks and new_sectors + */ + if (conf->scribble_disks >= new_disks && + conf->scribble_sectors >= new_sectors) + return 0; mddev_suspend(conf->mddev); get_online_cpus(); for_each_present_cpu(cpu) { @@ -2112,6 +2120,10 @@ static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors) } put_online_cpus(); mddev_resume(conf->mddev); + if (!err) { + conf->scribble_disks = new_disks; + conf->scribble_sectors = new_sectors; + } return err; } @@ -6414,6 +6426,12 @@ static int raid5_alloc_percpu(struct r5conf *conf) } put_online_cpus(); + if (!err) { + conf->scribble_disks = max(conf->raid_disks, + conf->previous_raid_disks); + conf->scribble_sectors = max(conf->chunk_sectors, + conf->prev_chunk_sectors); + } return err; } diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index a415e1cd39b8..ae6068deefdf 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -510,6 +510,8 @@ struct r5conf { * conversions */ } __percpu *percpu; + int scribble_disks; + int scribble_sectors; #ifdef CONFIG_HOTPLUG_CPU struct notifier_block cpu_notify; #endif |