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authorJonathan E Brassow <jbrassow@redhat.com>2005-11-21 21:32:37 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-22 09:14:31 -0800
commit7692c5dd48026d952199c2b97c3418f927cc0407 (patch)
treef198721b3b65a782ae0ed7400120cc45e0ce87c1 /drivers
parent233886dd32ad71daf9c21bf3728c0933a94870f0 (diff)
[PATCH] device-mapper raid1: drop mark_region spinlock fix
The spinlock region_lock is held while calling mark_region which can sleep. Drop the spinlock before calling that function. A region's state and inclusion in the clean list are altered by rh_inc and rh_dec. The state variable is set to RH_CLEAN in rh_dec, but only if 'pending' is zero. It is set to RH_DIRTY in rh_inc, but not if it is already so. The changes to 'pending', the state, and the region's inclusion in the clean list need to be atomicly. Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/dm-raid1.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 2375709a392..6b0fc167092 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -376,16 +376,18 @@ static void rh_inc(struct region_hash *rh, region_t region)
read_lock(&rh->hash_lock);
reg = __rh_find(rh, region);
+ spin_lock_irq(&rh->region_lock);
atomic_inc(&reg->pending);
- spin_lock_irq(&rh->region_lock);
if (reg->state == RH_CLEAN) {
- rh->log->type->mark_region(rh->log, reg->key);
-
reg->state = RH_DIRTY;
list_del_init(&reg->list); /* take off the clean list */
- }
- spin_unlock_irq(&rh->region_lock);
+ spin_unlock_irq(&rh->region_lock);
+
+ rh->log->type->mark_region(rh->log, reg->key);
+ } else
+ spin_unlock_irq(&rh->region_lock);
+
read_unlock(&rh->hash_lock);
}
@@ -408,21 +410,17 @@ static void rh_dec(struct region_hash *rh, region_t region)
reg = __rh_lookup(rh, region);
read_unlock(&rh->hash_lock);
+ spin_lock_irqsave(&rh->region_lock, flags);
if (atomic_dec_and_test(&reg->pending)) {
- spin_lock_irqsave(&rh->region_lock, flags);
- if (atomic_read(&reg->pending)) { /* check race */
- spin_unlock_irqrestore(&rh->region_lock, flags);
- return;
- }
if (reg->state == RH_RECOVERING) {
list_add_tail(&reg->list, &rh->quiesced_regions);
} else {
reg->state = RH_CLEAN;
list_add(&reg->list, &rh->clean_regions);
}
- spin_unlock_irqrestore(&rh->region_lock, flags);
should_wake = 1;
}
+ spin_unlock_irqrestore(&rh->region_lock, flags);
if (should_wake)
wake();