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 <tj@kernel.org>
Cc: unsik Kim <donari75@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Tejun Heo 2009-05-08 11:54:00 +09:00 committed by Jens Axboe
parent 8f6205cd57
commit 9a8d23d885

View File

@ -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;