blkcg: use blkg_free() in blkcg_init_queue() failure path

When blkcg_init_queue() fails midway after creating a new blkg, it
performs kfree() directly; however, this doesn't free the policy data
areas.  Make it use blkg_free() instead.  In turn, blkg_free() is
updated to handle root request_list special case.

While this fixes a possible memory leak, it's on an unlikely failure
path of an already cold path and the size leaked per occurrence is
miniscule too.  I don't think it needs to be tagged for -stable.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Tejun Heo 2015-08-18 14:55:07 -07:00 committed by Jens Axboe
parent 401efbf835
commit 994b783274

View File

@ -70,7 +70,8 @@ static void blkg_free(struct blkcg_gq *blkg)
for (i = 0; i < BLKCG_MAX_POLS; i++)
kfree(blkg->pd[i]);
blk_exit_rl(&blkg->rl);
if (blkg->blkcg != &blkcg_root)
blk_exit_rl(&blkg->rl);
kfree(blkg);
}
@ -938,7 +939,7 @@ int blkcg_init_queue(struct request_queue *q)
radix_tree_preload_end();
if (IS_ERR(blkg)) {
kfree(new_blkg);
blkg_free(new_blkg);
return PTR_ERR(blkg);
}