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| author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2010-07-08 10:16:17 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-08-07 18:24:28 +0200 |
| commit | 610a63498f7f366031a6327eaaa9963ffa110b2b (patch) | |
| tree | 8ea7f0c9e1e2f41ee09677909a3491adeee31799 | |
| parent | writeback: Add tracing to write_cache_pages (diff) | |
| download | linux-610a63498f7f366031a6327eaaa9963ffa110b2b.tar.xz linux-610a63498f7f366031a6327eaaa9963ffa110b2b.zip | |
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>
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 7 | ||||
| -rw-r--r-- | drivers/scsi/sd.c | 10 |
2 files changed, 10 insertions, 7 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index ee836193f531..b8de389636f8 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1011,11 +1011,8 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) err_exit: scsi_release_buffers(cmd); - if (error == BLKPREP_KILL) - scsi_put_command(cmd); - else /* BLKPREP_DEFER */ - scsi_unprep_request(cmd->request); - + scsi_put_command(cmd); + cmd->request->special = NULL; return error; } EXPORT_SYMBOL(scsi_init_io); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 0994ab63b598..1d0c4b7c3b69 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -468,6 +468,10 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) 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 int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq) 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; + } } /** |