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blk-throttle: Take blkcg->lock while traversing blkcg->policy_list

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blkcg->policy_list is protected by blkcg->lock. Its not rcu protected
list. So even for readers, they need to take blkcg->lock. There are
few functions which were reading the list without taking lock. Fix it.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Vivek Goyal 2011-10-25 15:48:12 +02:00 committed by Jens Axboe
parent e060f00bee
commit a38eb630fa
1 changed files with 40 additions and 14 deletions
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54
block/blk-cgroup.c
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@ -869,60 +869,86 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
dev_t dev) dev_t dev)
{ {
struct blkio_policy_node *pn; struct blkio_policy_node *pn;
unsigned long flags;
unsigned int weight;
spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP, pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
BLKIO_PROP_weight_device); BLKIO_PROP_weight_device);
if (pn) if (pn)
return pn->val.weight; weight = pn->val.weight;
else else
return blkcg->weight; weight = blkcg->weight;
spin_unlock_irqrestore(&blkcg->lock, flags);
return weight;
} }
EXPORT_SYMBOL_GPL(blkcg_get_weight); EXPORT_SYMBOL_GPL(blkcg_get_weight);
uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
{ {
struct blkio_policy_node *pn; struct blkio_policy_node *pn;
unsigned long flags;
uint64_t bps = -1;
spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_read_bps_device); BLKIO_THROTL_read_bps_device);
if (pn) if (pn)
return pn->val.bps; bps = pn->val.bps;
else spin_unlock_irqrestore(&blkcg->lock, flags);
return -1;
return bps;
} }
uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
{ {
struct blkio_policy_node *pn; struct blkio_policy_node *pn;
unsigned long flags;
uint64_t bps = -1;
spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_write_bps_device); BLKIO_THROTL_write_bps_device);
if (pn) if (pn)
return pn->val.bps; bps = pn->val.bps;
else spin_unlock_irqrestore(&blkcg->lock, flags);
return -1;
return bps;
} }
unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
{ {
struct blkio_policy_node *pn; struct blkio_policy_node *pn;
unsigned long flags;
unsigned int iops = -1;
spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_read_iops_device); BLKIO_THROTL_read_iops_device);
if (pn) if (pn)
return pn->val.iops; iops = pn->val.iops;
else spin_unlock_irqrestore(&blkcg->lock, flags);
return -1;
return iops;
} }
unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
{ {
struct blkio_policy_node *pn; struct blkio_policy_node *pn;
unsigned long flags;
unsigned int iops = -1;
spin_lock_irqsave(&blkcg->lock, flags);
pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL, pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
BLKIO_THROTL_write_iops_device); BLKIO_THROTL_write_iops_device);
if (pn) if (pn)
return pn->val.iops; iops = pn->val.iops;
else spin_unlock_irqrestore(&blkcg->lock, flags);
return -1;
return iops;
} }
/* Checks whether user asked for deleting a policy rule */ /* Checks whether user asked for deleting a policy rule */