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authorNeilBrown <neilb@suse.de>2006-10-03 01:15:53 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-03 08:04:18 -0700
commitc04be0aa82ff535e3676ab3e573957bdeef41879 (patch)
tree8481ab270218bed246eb02b3ba04a4b84d4e90d0 /drivers/md/raid1.c
parent11ce99e625fe2718ad2682bfdd99070b337e6252 (diff)
downloadlinux-c04be0aa82ff535e3676ab3e573957bdeef41879.tar.bz2
[PATCH] md: Improve locking around error handling
The error handling routines don't use proper locking, and so two concurrent errors could trigger a problem. So: - use test-and-set and test-and-clear to synchonise the In_sync bits with the ->degraded count - use the spinlock to protect updates to the degraded count (could use an atomic_t but that would be a bigger change in code, and isn't really justified) - remove un-necessary locking in raid5 Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/raid1.c')
-rw-r--r--drivers/md/raid1.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 3fc9ec239478..99c4e031c7f1 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -959,14 +959,16 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
* normal single drive
*/
return;
- if (test_bit(In_sync, &rdev->flags)) {
+ if (test_and_clear_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
/*
* if recovery is running, make sure it aborts.
*/
set_bit(MD_RECOVERY_ERR, &mddev->recovery);
}
- clear_bit(In_sync, &rdev->flags);
set_bit(Faulty, &rdev->flags);
set_bit(MD_CHANGE_DEVS, &mddev->flags);
printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
@@ -1022,9 +1024,11 @@ static int raid1_spare_active(mddev_t *mddev)
mdk_rdev_t *rdev = conf->mirrors[i].rdev;
if (rdev
&& !test_bit(Faulty, &rdev->flags)
- && !test_bit(In_sync, &rdev->flags)) {
+ && !test_and_set_bit(In_sync, &rdev->flags)) {
+ unsigned long flags;
+ spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded--;
- set_bit(In_sync, &rdev->flags);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
}
}
@@ -2048,7 +2052,7 @@ static int raid1_reshape(mddev_t *mddev)
mirror_info_t *newmirrors;
conf_t *conf = mddev_to_conf(mddev);
int cnt, raid_disks;
-
+ unsigned long flags;
int d, d2;
/* Cannot change chunk_size, layout, or level */
@@ -2107,7 +2111,9 @@ static int raid1_reshape(mddev_t *mddev)
kfree(conf->poolinfo);
conf->poolinfo = newpoolinfo;
+ spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded += (raid_disks - conf->raid_disks);
+ spin_unlock_irqrestore(&conf->device_lock, flags);
conf->raid_disks = mddev->raid_disks = raid_disks;
mddev->delta_disks = 0;