diff options
| -rw-r--r-- | block/blk-core.c | 32 | ||||
| -rw-r--r-- | block/blk-lib.c | 33 | ||||
| -rw-r--r-- | drivers/scsi/sd.c | 52 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 2 |
4 files changed, 74 insertions, 45 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 66c3cfe..3531d8e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1135,6 +1135,38 @@ void blk_put_request(struct request *req) } EXPORT_SYMBOL(blk_put_request); +/** + * blk_add_request_payload - add a payload to a request + * @rq: request to update + * @page: page backing the payload + * @len: length of the payload. + * + * This allows to later add a payload to an already submitted request by + * a block driver. The driver needs to take care of freeing the payload + * itself. + * + * Note that this is a quite horrible hack and nothing but handling of + * discard requests should ever use it. + */ +void blk_add_request_payload(struct request *rq, struct page *page, + unsigned int len) +{ + struct bio *bio = rq->bio; + + bio->bi_io_vec->bv_page = page; + bio->bi_io_vec->bv_offset = 0; + bio->bi_io_vec->bv_len = len; + + bio->bi_size = len; + bio->bi_vcnt = 1; + bio->bi_phys_segments = 1; + + rq->__data_len = rq->resid_len = len; + rq->nr_phys_segments = 1; + rq->buffer = bio_data(bio); +} +EXPORT_SYMBOL_GPL(blk_add_request_payload); + void init_request_from_bio(struct request *req, struct bio *bio) { req->cpu = bio->bi_comp_cpu; diff --git a/block/blk-lib.c b/block/blk-lib.c index d0216b9..e16185b 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -19,7 +19,6 @@ static void blkdev_discard_end_io(struct bio *bio, int err) if (bio->bi_private) complete(bio->bi_private); - __free_page(bio_page(bio)); bio_put(bio); } @@ -43,7 +42,6 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, int type = flags & BLKDEV_IFL_BARRIER ? DISCARD_BARRIER : DISCARD_NOBARRIER; struct bio *bio; - struct page *page; int ret = 0; if (!q) @@ -53,35 +51,21 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, return -EOPNOTSUPP; while (nr_sects && !ret) { - unsigned int sector_size = q->limits.logical_block_size; unsigned int max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); bio = bio_alloc(gfp_mask, 1); - if (!bio) - goto out; + if (!bio) { + ret = -ENOMEM; + break; + } + bio->bi_sector = sector; bio->bi_end_io = blkdev_discard_end_io; bio->bi_bdev = bdev; if (flags & BLKDEV_IFL_WAIT) bio->bi_private = &wait; - /* - * Add a zeroed one-sector payload as that's what - * our current implementations need. If we'll ever need - * more the interface will need revisiting. - */ - page = alloc_page(gfp_mask | __GFP_ZERO); - if (!page) - goto out_free_bio; - if (bio_add_pc_page(q, bio, page, sector_size, 0) < sector_size) - goto out_free_page; - - /* - * And override the bio size - the way discard works we - * touch many more blocks on disk than the actual payload - * length. - */ if (nr_sects > max_discard_sectors) { bio->bi_size = max_discard_sectors << 9; nr_sects -= max_discard_sectors; @@ -103,13 +87,8 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, ret = -EIO; bio_put(bio); } + return ret; -out_free_page: - __free_page(page); -out_free_bio: - bio_put(bio); -out: - return -ENOMEM; } EXPORT_SYMBOL(blkdev_issue_discard); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index a3fdf4d..86da819 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -411,22 +411,25 @@ static void sd_prot_op(struct scsi_cmnd *scmd, unsigned int dif) } /** - * sd_prepare_discard - unmap blocks on thinly provisioned device + * scsi_setup_discard_cmnd - unmap blocks on thinly provisioned device + * @sdp: scsi device to operate one * @rq: Request to prepare * * Will issue either UNMAP or WRITE SAME(16) depending on preference * indicated by target device. **/ -static int sd_prepare_discard(struct request *rq) +static int scsi_setup_discard_cmnd(struct scsi_device *sdp, struct request *rq) { struct scsi_disk *sdkp = scsi_disk(rq->rq_disk); struct bio *bio = rq->bio; sector_t sector = bio->bi_sector; - unsigned int num = bio_sectors(bio); + unsigned int nr_sectors = bio_sectors(bio); + unsigned int len; + struct page *page; if (sdkp->device->sector_size == 4096) { sector >>= 3; - num >>= 3; + nr_sectors >>= 3; } rq->cmd_type = REQ_TYPE_BLOCK_PC; @@ -434,31 +437,35 @@ static int sd_prepare_discard(struct request *rq) memset(rq->cmd, 0, rq->cmd_len); + page = alloc_page(GFP_ATOMIC | __GFP_ZERO); + if (!page) + return BLKPREP_DEFER; + if (sdkp->unmap) { - char *buf = kmap_atomic(bio_page(bio), KM_USER0); + char *buf = page_address(page); + rq->cmd_len = 10; rq->cmd[0] = UNMAP; rq->cmd[8] = 24; - rq->cmd_len = 10; - - /* Ensure that data length matches payload */ - rq->__data_len = bio->bi_size = bio->bi_io_vec->bv_len = 24; put_unaligned_be16(6 + 16, &buf[0]); put_unaligned_be16(16, &buf[2]); put_unaligned_be64(sector, &buf[8]); - put_unaligned_be32(num, &buf[16]); + put_unaligned_be32(nr_sectors, &buf[16]); - kunmap_atomic(buf, KM_USER0); + len = 24; } else { + rq->cmd_len = 16; rq->cmd[0] = WRITE_SAME_16; rq->cmd[1] = 0x8; /* UNMAP */ put_unaligned_be64(sector, &rq->cmd[2]); - put_unaligned_be32(num, &rq->cmd[10]); - rq->cmd_len = 16; + put_unaligned_be32(nr_sectors, &rq->cmd[10]); + + len = sdkp->device->sector_size; } - return BLKPREP_OK; + blk_add_request_payload(rq, page, len); + return scsi_setup_blk_pc_cmnd(sdp, rq); } /** @@ -485,10 +492,10 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq) * Discard request come in as REQ_TYPE_FS but we turn them into * block PC requests to make life easier. */ - if (rq->cmd_flags & REQ_DISCARD) - ret = sd_prepare_discard(rq); - - if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { + if (rq->cmd_flags & REQ_DISCARD) { + ret = scsi_setup_discard_cmnd(sdp, rq); + goto out; + } else if (rq->cmd_type == REQ_TYPE_BLOCK_PC) { ret = scsi_setup_blk_pc_cmnd(sdp, rq); goto out; } else if (rq->cmd_type != REQ_TYPE_FS) { @@ -1163,6 +1170,15 @@ 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) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3fc0f59..204fbe2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -705,6 +705,8 @@ extern struct request *blk_make_request(struct request_queue *, struct bio *, gfp_t); extern void blk_insert_request(struct request_queue *, struct request *, int, void *); extern void blk_requeue_request(struct request_queue *, struct request *); +extern void blk_add_request_payload(struct request *rq, struct page *page, + unsigned int len); extern int blk_rq_check_limits(struct request_queue *q, struct request *rq); extern int blk_lld_busy(struct request_queue *q); extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src, |
