On Sat, 26 Jun 2010 15:56:50 -0400 Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > Fix leaks introduced via "block: don't allocate a payload for discard > request" commit a1d949f5f44. > > sd_done() is not called for REQ_TYPE_BLOCK_PC commands so cleanup > discard request's payload directly in scsi_finish_command(). Instead of adding another discard hack to scsi_finish_command(), how about converting discard to REQ_TYPE_FS request? discard is FS request from the perspective of the block layer. It also fixes a problem that discard isn't retried in the case of UNIT ATTENTION. I think that we can get more cleaner code if we handle discard as normal (fs) request in the block layer (and scsi-ml). We need more changes but this patch is the first step. This patch depends on the patchset to convert flush request to REQ_TYPE_FS: http://marc.info/?l=linux-kernel&m=127730591527424&w=2 The git tree is also available: git://git.kernel.org/pub/scm/linux/kernel/git/tomo/linux-2.6-misc.git flush > Also cleanup page allocated for discard payload in > scsi_setup_discard_cmnd's scsi_setup_blk_pc_cmnd error path. This patch doesn't address on this (since it's a different problem). I think that scsi_setup_discard_cmnd() sees if it already allocates a page before allocating a page. That's similar to how other prep functions work, I think. = From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Subject: [PATCH] convert discard request to REQ_TYPE_FS instead of BLOCK_PC Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- block/blk-lib.c | 4 ++++ drivers/scsi/sd.c | 11 +---------- 2 files changed, 5 insertions(+), 10 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index e16185b..9e15c46 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -20,6 +20,10 @@ static void blkdev_discard_end_io(struct bio *bio, int err) if (bio->bi_private) complete(bio->bi_private); + /* free the page that the lower layer allocated */ + if (bio_page(bio)) + __free_page(bio_page(bio)); + bio_put(bio); } diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d447726..1b182de 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -432,7 +432,7 @@ static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) nr_sectors >>= 3; } - rq->cmd_type = REQ_TYPE_BLOCK_PC; + rq->cmd_type = REQ_TYPE_FS; rq->timeout = SD_TIMEOUT; memset(rq->cmd, 0, rq->cmd_len); @@ -1177,15 +1177,6 @@ static int sd_done(struct scsi_cmnd *SCpnt) int sense_valid = 0; int sense_deferred = 0; - /* - * If this is a discard request that originated from the kernel - * we need to free our payload here. Note that we need to check - * the request flag as the normal payload rules apply for - * pass-through UNMAP / WRITE SAME requests. - */ - if (SCpnt->request->cmd_flags & REQ_DISCARD) - __free_page(bio_page(SCpnt->request->bio)); - if (result) { sense_valid = scsi_command_normalize_sense(SCpnt, &sshdr); if (sense_valid) -- 1.6.5 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
