From 7692c5dd48026d952199c2b97c3418f927cc0407 Mon Sep 17 00:00:00 2001 From: Jonathan E Brassow Date: Mon, 21 Nov 2005 21:32:37 -0800 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/dm-raid1.c | 20 +++++++++----------- 1 file 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(®->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(®->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(®->pending)) { - spin_lock_irqsave(&rh->region_lock, flags); - if (atomic_read(®->pending)) { /* check race */ - spin_unlock_irqrestore(&rh->region_lock, flags); - return; - } if (reg->state == RH_RECOVERING) { list_add_tail(®->list, &rh->quiesced_regions); } else { reg->state = RH_CLEAN; list_add(®->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(); -- 2.20.1