scsi: fix discard page leak
We leak a page allocated for discard on some error conditions
(e.g. scsi_prep_state_check returns BLKPREP_DEFER in
scsi_setup_blk_pc_cmnd).
We unprep on requests that weren't prepped in the error path of
scsi_init_io. It makes the error path to clean up scsi commands messy.
Let's strictly apply the rule that we can't unprep on a request that
wasn't prepped.
Calling just scsi_put_command() in the error path of scsi_init_io() is
enough. We don't set REQ_DONTPREP yet.
scsi_setup_discard_cmnd can safely free a page on the error case with
the above rule.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0994ab6..1d0c4b7 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -468,6 +468,10 @@
blk_add_request_payload(rq, page, len);
ret = scsi_setup_blk_pc_cmnd(sdp, rq);
rq->buffer = page_address(page);
+ if (ret != BLKPREP_OK) {
+ __free_page(page);
+ rq->buffer = NULL;
+ }
return ret;
}
@@ -485,8 +489,10 @@
static void sd_unprep_fn(struct request_queue *q, struct request *rq)
{
- if (rq->cmd_flags & REQ_DISCARD)
- __free_page(virt_to_page(rq->buffer));
+ if (rq->cmd_flags & REQ_DISCARD) {
+ free_page((unsigned long)rq->buffer);
+ rq->buffer = NULL;
+ }
}
/**