From f1126e950d28ff875d96ed6a04a9ff96c7bfc357 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Thu, 1 Jul 2010 19:49:18 +0900 Subject: [PATCH] scsi: add sd_unprep_fn to free discard page This fixes discard page leak by using q->unprep_rq_fn facility. q->unprep_rq_fn is called when all the data buffer (req->bio and scsi_data_buffer) in the request is freed. sd_unprep() uses rq->buffer to free discard page allocated in sd_prepare_discard(). Signed-off-by: FUJITA Tomonori Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 86da819c70eb..2d4e3a865f39 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -425,6 +425,7 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) sector_t sector = bio->bi_sector; unsigned int nr_sectors = bio_sectors(bio); unsigned int len; + int ret; struct page *page; if (sdkp->device->sector_size == 4096) { @@ -465,7 +466,15 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) } blk_add_request_payload(rq, page, len); - return scsi_setup_blk_pc_cmnd(sdp, rq); + ret = scsi_setup_blk_pc_cmnd(sdp, rq); + rq->buffer = page_address(page); + return ret; +} + +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)); } /** @@ -2242,6 +2251,7 @@ static void sd_probe_async(void *data, async_cookie_t cookie) sd_revalidate_disk(gd); blk_queue_prep_rq(sdp->request_queue, sd_prep_fn); + blk_queue_unprep_rq(sdp->request_queue, sd_unprep_fn); gd->driverfs_dev = &sdp->sdev_gendev; gd->flags = GENHD_FL_EXT_DEVT;