From 9a8d23d8855e554fc5887f14cb008b55c4300ccc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 8 May 2009 11:54:00 +0900 Subject: [PATCH] mg_disk: fix queue hang / infinite retry on !fs requests Both request functions in mg_disk simply return when they encounter a !fs request, which means the request will never be cleared from the queue causing queue hang and indefinite retry of the request. Fix it. While at it, flatten condition checks and add unlikely to !fs tests. [ Impact: fix possible queue hang / infinite retry of !fs requests ] Signed-off-by: Tejun Heo Cc: unsik Kim Signed-off-by: Jens Axboe --- drivers/block/mg_disk.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/block/mg_disk.c b/drivers/block/mg_disk.c index 826c3492b9fe..be323880f24a 100644 --- a/drivers/block/mg_disk.c +++ b/drivers/block/mg_disk.c @@ -672,16 +672,16 @@ static void mg_request_poll(struct request_queue *q) while ((req = elv_next_request(q)) != NULL) { host = req->rq_disk->private_data; - if (blk_fs_request(req)) { - switch (rq_data_dir(req)) { - case READ: - mg_read(req); - break; - case WRITE: - mg_write(req); - break; - } + + if (unlikely(!blk_fs_request(req))) { + __blk_end_request_cur(req, -EIO); + continue; } + + if (rq_data_dir(req) == READ) + mg_read(req); + else + mg_write(req); } } @@ -766,8 +766,10 @@ static void mg_request(struct request_queue *q) continue; } - if (!blk_fs_request(req)) - return; + if (unlikely(!blk_fs_request(req))) { + __blk_end_request_cur(req, -EIO); + continue; + } if (!mg_issue_req(req, host, sect_num, sect_cnt)) return;