diff options
| author | Vivek Goyal <vgoyal@redhat.com> | 2011-10-25 15:48:12 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2011-10-25 15:48:12 +0200 |
| commit | a38eb630fa224d6fba8c14a4063174bc5e0f63bb (patch) | |
| tree | b86cb5b0aaa4b6d45d798b5155ed2089177f8206 /block | |
| parent | e060f00beee23568fe2c4faf1e88ff22edefd7b2 (diff) | |
| download | linux-rt-a38eb630fa224d6fba8c14a4063174bc5e0f63bb.tar.gz | |
blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
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>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-cgroup.c | 54 |
1 files changed, 40 insertions, 14 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 61553670735d..8f630cec906e 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -869,60 +869,86 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg, dev_t dev) { 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, BLKIO_PROP_weight_device); if (pn) - return pn->val.weight; + weight = pn->val.weight; else - return blkcg->weight; + weight = blkcg->weight; + + spin_unlock_irqrestore(&blkcg->lock, flags); + + return weight; } EXPORT_SYMBOL_GPL(blkcg_get_weight); uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev) { 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, BLKIO_THROTL_read_bps_device); if (pn) - return pn->val.bps; - else - return -1; + bps = pn->val.bps; + spin_unlock_irqrestore(&blkcg->lock, flags); + + return bps; } uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev) { 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, BLKIO_THROTL_write_bps_device); if (pn) - return pn->val.bps; - else - return -1; + bps = pn->val.bps; + spin_unlock_irqrestore(&blkcg->lock, flags); + + return bps; } unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev) { 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, BLKIO_THROTL_read_iops_device); if (pn) - return pn->val.iops; - else - return -1; + iops = pn->val.iops; + spin_unlock_irqrestore(&blkcg->lock, flags); + + return iops; } unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev) { 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, BLKIO_THROTL_write_iops_device); if (pn) - return pn->val.iops; - else - return -1; + iops = pn->val.iops; + spin_unlock_irqrestore(&blkcg->lock, flags); + + return iops; } /* Checks whether user asked for deleting a policy rule */ |