diff options
Diffstat (limited to 'drivers/block/loop.c')
| -rw-r--r-- | drivers/block/loop.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 839373451c2b..28eb59fd71ca 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1859,35 +1859,44 @@ static blk_status_t loop_queue_rq(struct blk_mq_hw_ctx *hctx, static void loop_handle_cmd(struct loop_cmd *cmd) { + struct cgroup_subsys_state *cmd_blkcg_css = cmd->blkcg_css; + struct cgroup_subsys_state *cmd_memcg_css = cmd->memcg_css; struct request *rq = blk_mq_rq_from_pdu(cmd); const bool write = op_is_write(req_op(rq)); struct loop_device *lo = rq->q->queuedata; int ret = 0; struct mem_cgroup *old_memcg = NULL; + const bool use_aio = cmd->use_aio; if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) { ret = -EIO; goto failed; } - if (cmd->blkcg_css) - kthread_associate_blkcg(cmd->blkcg_css); - if (cmd->memcg_css) + if (cmd_blkcg_css) + kthread_associate_blkcg(cmd_blkcg_css); + if (cmd_memcg_css) old_memcg = set_active_memcg( - mem_cgroup_from_css(cmd->memcg_css)); + mem_cgroup_from_css(cmd_memcg_css)); + /* + * do_req_filebacked() may call blk_mq_complete_request() synchronously + * or asynchronously if using aio. Hence, do not touch 'cmd' after + * do_req_filebacked() has returned unless we are sure that 'cmd' has + * not yet been completed. + */ ret = do_req_filebacked(lo, rq); - if (cmd->blkcg_css) + if (cmd_blkcg_css) kthread_associate_blkcg(NULL); - if (cmd->memcg_css) { + if (cmd_memcg_css) { set_active_memcg(old_memcg); - css_put(cmd->memcg_css); + css_put(cmd_memcg_css); } failed: /* complete non-aio request */ - if (!cmd->use_aio || ret) { + if (!use_aio || ret) { if (ret == -EOPNOTSUPP) cmd->ret = ret; else |