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author | Martin K. Petersen <martin.petersen@oracle.com> | 2012-09-18 16:19:32 (GMT) |
---|---|---|
committer | James Bottomley <JBottomley@Parallels.com> | 2012-11-14 06:45:42 (GMT) |
commit | 5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd (patch) | |
tree | a352bab202b6cb40f234bd2fd306b54776543e8b /drivers/scsi | |
parent | 26e85fcd15f68b57d9ba645cd3591117a8ac0e05 (diff) | |
download | linux-fsl-qoriq-5db44863b6ebbb400c5e61d56ebe8f21ef48b1bd.tar.xz |
[SCSI] sd: Implement support for WRITE SAME
Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.
- We set the default maximum to 0xFFFF because there are several
devices out there that only support two-byte block counts even with
WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
LIMITS VPD.
- max_write_same_blocks can be overriden per-device basis in sysfs.
- The UNMAP discovery heuristics remain unchanged but the discard
limits are tweaked to match the "real" WRITE SAME commands.
- In the error handling logic we now distinguish between WRITE SAME
with and without UNMAP set.
The discovery process heuristics are:
- If the device reports a SCSI level of SPC-3 or greater we'll issue
READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
supported. If that's the case we will use it.
- If the device supports the block limits VPD and reports a MAXIMUM
WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).
- Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
0xFFFFFFFF or the block count exceeds 0xFFFF.
- no_write_same is set for ATA, FireWire and USB.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r-- | drivers/scsi/scsi_lib.c | 22 | ||||
-rw-r--r-- | drivers/scsi/sd.c | 172 | ||||
-rw-r--r-- | drivers/scsi/sd.h | 7 |
3 files changed, 185 insertions, 16 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index da36a3a..9032e91 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -900,11 +900,23 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) action = ACTION_FAIL; error = -EILSEQ; /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ - } else if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) && - (cmd->cmnd[0] == UNMAP || - cmd->cmnd[0] == WRITE_SAME_16 || - cmd->cmnd[0] == WRITE_SAME)) { - description = "Discard failure"; + } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { + switch (cmd->cmnd[0]) { + case UNMAP: + description = "Discard failure"; + break; + case WRITE_SAME: + case WRITE_SAME_16: + if (cmd->cmnd[1] & 0x8) + description = "Discard failure"; + else + description = + "Write same failure"; + break; + default: + description = "Invalid command failure"; + break; + } action = ACTION_FAIL; error = -EREMOTEIO; } else diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index c6af4c1..352bc77 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -99,6 +99,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC); #endif static void sd_config_discard(struct scsi_disk *, unsigned int); +static void sd_config_write_same(struct scsi_disk *); static int sd_revalidate_disk(struct gendisk *); static void sd_unlock_native_capacity(struct gendisk *disk); static int sd_probe(struct device *); @@ -395,6 +396,45 @@ sd_store_max_medium_access_timeouts(struct device *dev, return err ? err : count; } +static ssize_t +sd_show_write_same_blocks(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct scsi_disk *sdkp = to_scsi_disk(dev); + + return snprintf(buf, 20, "%u\n", sdkp->max_ws_blocks); +} + +static ssize_t +sd_store_write_same_blocks(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct scsi_disk *sdkp = to_scsi_disk(dev); + struct scsi_device *sdp = sdkp->device; + unsigned long max; + int err; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (sdp->type != TYPE_DISK) + return -EINVAL; + + err = kstrtoul(buf, 10, &max); + + if (err) + return err; + + if (max == 0) + sdp->no_write_same = 1; + else if (max <= SD_MAX_WS16_BLOCKS) + sdkp->max_ws_blocks = max; + + sd_config_write_same(sdkp); + + return count; +} + static struct device_attribute sd_disk_attrs[] = { __ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type, sd_store_cache_type), @@ -410,6 +450,8 @@ static struct device_attribute sd_disk_attrs[] = { __ATTR(thin_provisioning, S_IRUGO, sd_show_thin_provisioning, NULL), __ATTR(provisioning_mode, S_IRUGO|S_IWUSR, sd_show_provisioning_mode, sd_store_provisioning_mode), + __ATTR(max_write_same_blocks, S_IRUGO|S_IWUSR, + sd_show_write_same_blocks, sd_store_write_same_blocks), __ATTR(max_medium_access_timeouts, S_IRUGO|S_IWUSR, sd_show_max_medium_access_timeouts, sd_store_max_medium_access_timeouts), @@ -561,19 +603,23 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode) return; case SD_LBP_UNMAP: - max_blocks = min_not_zero(sdkp->max_unmap_blocks, 0xffffffff); + max_blocks = min_not_zero(sdkp->max_unmap_blocks, + (u32)SD_MAX_WS16_BLOCKS); break; case SD_LBP_WS16: - max_blocks = min_not_zero(sdkp->max_ws_blocks, 0xffffffff); + max_blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS16_BLOCKS); break; case SD_LBP_WS10: - max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff); + max_blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS10_BLOCKS); break; case SD_LBP_ZERO: - max_blocks = min_not_zero(sdkp->max_ws_blocks, (u32)0xffff); + max_blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS10_BLOCKS); q->limits.discard_zeroes_data = 1; break; } @@ -667,6 +713,83 @@ out: return ret; } +static void sd_config_write_same(struct scsi_disk *sdkp) +{ + struct request_queue *q = sdkp->disk->queue; + unsigned int logical_block_size = sdkp->device->sector_size; + unsigned int blocks = 0; + + if (sdkp->device->no_write_same) { + sdkp->max_ws_blocks = 0; + goto out; + } + + /* Some devices can not handle block counts above 0xffff despite + * supporting WRITE SAME(16). Consequently we default to 64k + * blocks per I/O unless the device explicitly advertises a + * bigger limit. + */ + if (sdkp->max_ws_blocks == 0) + sdkp->max_ws_blocks = SD_MAX_WS10_BLOCKS; + + if (sdkp->ws16 || sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS) + blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS16_BLOCKS); + else + blocks = min_not_zero(sdkp->max_ws_blocks, + (u32)SD_MAX_WS10_BLOCKS); + +out: + blk_queue_max_write_same_sectors(q, blocks * (logical_block_size >> 9)); +} + +/** + * sd_setup_write_same_cmnd - write the same data to multiple blocks + * @sdp: scsi device to operate one + * @rq: Request to prepare + * + * Will issue either WRITE SAME(10) or WRITE SAME(16) depending on + * preference indicated by target device. + **/ +static int sd_setup_write_same_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 = blk_rq_pos(rq); + unsigned int nr_sectors = blk_rq_sectors(rq); + unsigned int nr_bytes = blk_rq_bytes(rq); + int ret; + + if (sdkp->device->no_write_same) + return BLKPREP_KILL; + + BUG_ON(bio_offset(bio) || bio_iovec(bio)->bv_len != sdp->sector_size); + + sector >>= ilog2(sdp->sector_size) - 9; + nr_sectors >>= ilog2(sdp->sector_size) - 9; + + rq->__data_len = sdp->sector_size; + rq->timeout = SD_WRITE_SAME_TIMEOUT; + memset(rq->cmd, 0, rq->cmd_len); + + if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff) { + rq->cmd_len = 16; + rq->cmd[0] = WRITE_SAME_16; + put_unaligned_be64(sector, &rq->cmd[2]); + put_unaligned_be32(nr_sectors, &rq->cmd[10]); + } else { + rq->cmd_len = 10; + rq->cmd[0] = WRITE_SAME; + put_unaligned_be32(sector, &rq->cmd[2]); + put_unaligned_be16(nr_sectors, &rq->cmd[7]); + } + + ret = scsi_setup_blk_pc_cmnd(sdp, rq); + rq->__data_len = nr_bytes; + + return ret; +} + static int scsi_setup_flush_cmnd(struct scsi_device *sdp, struct request *rq) { rq->timeout = SD_FLUSH_TIMEOUT; @@ -712,6 +835,9 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq) if (rq->cmd_flags & REQ_DISCARD) { ret = sd_setup_discard_cmnd(sdp, rq); goto out; + } else if (rq->cmd_flags & REQ_WRITE_SAME) { + ret = sd_setup_write_same_cmnd(sdp, rq); + goto out; } else if (rq->cmd_flags & REQ_FLUSH) { ret = scsi_setup_flush_cmnd(sdp, rq); goto out; @@ -1484,8 +1610,9 @@ static int sd_done(struct scsi_cmnd *SCpnt) int sense_valid = 0; int sense_deferred = 0; unsigned char op = SCpnt->cmnd[0]; + unsigned char unmap = SCpnt->cmnd[1] & 8; - if (req->cmd_flags & REQ_DISCARD) { + if (req->cmd_flags & REQ_DISCARD || req->cmd_flags & REQ_WRITE_SAME) { if (!result) { good_bytes = blk_rq_bytes(req); scsi_set_resid(SCpnt, 0); @@ -1542,9 +1669,25 @@ static int sd_done(struct scsi_cmnd *SCpnt) if (sshdr.asc == 0x10) /* DIX: Host detected corruption */ good_bytes = sd_completed_bytes(SCpnt); /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ - if ((sshdr.asc == 0x20 || sshdr.asc == 0x24) && - (op == UNMAP || op == WRITE_SAME_16 || op == WRITE_SAME)) - sd_config_discard(sdkp, SD_LBP_DISABLE); + if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { + switch (op) { + case UNMAP: + sd_config_discard(sdkp, SD_LBP_DISABLE); + break; + case WRITE_SAME_16: + case WRITE_SAME: + if (unmap) + sd_config_discard(sdkp, SD_LBP_DISABLE); + else { + sdkp->device->no_write_same = 1; + sd_config_write_same(sdkp); + + good_bytes = 0; + req->__data_len = blk_rq_bytes(req); + req->cmd_flags |= REQ_QUIET; + } + } + } break; default: break; @@ -2380,9 +2523,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp) if (buffer[3] == 0x3c) { unsigned int lba_count, desc_count; - sdkp->max_ws_blocks = - (u32) min_not_zero(get_unaligned_be64(&buffer[36]), - (u64)0xffffffff); + sdkp->max_ws_blocks = (u32)get_unaligned_be64(&buffer[36]); if (!sdkp->lbpme) goto out; @@ -2475,6 +2616,13 @@ static void sd_read_block_provisioning(struct scsi_disk *sdkp) kfree(buffer); } +static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer) +{ + if (scsi_report_opcode(sdkp->device, buffer, SD_BUF_SIZE, + WRITE_SAME_16)) + sdkp->ws16 = 1; +} + static int sd_try_extended_inquiry(struct scsi_device *sdp) { /* @@ -2534,6 +2682,7 @@ static int sd_revalidate_disk(struct gendisk *disk) sd_read_write_protect_flag(sdkp, buffer); sd_read_cache_type(sdkp, buffer); sd_read_app_tag_own(sdkp, buffer); + sd_read_write_same(sdkp, buffer); } sdkp->first_scan = 0; @@ -2551,6 +2700,7 @@ static int sd_revalidate_disk(struct gendisk *disk) blk_queue_flush(sdkp->disk->queue, flush); set_capacity(disk, sdkp->capacity); + sd_config_write_same(sdkp); kfree(buffer); out: diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h index 47c52a6..74a1e4c 100644 --- a/drivers/scsi/sd.h +++ b/drivers/scsi/sd.h @@ -14,6 +14,7 @@ #define SD_TIMEOUT (30 * HZ) #define SD_MOD_TIMEOUT (75 * HZ) #define SD_FLUSH_TIMEOUT (60 * HZ) +#define SD_WRITE_SAME_TIMEOUT (120 * HZ) /* * Number of allowed retries @@ -39,6 +40,11 @@ enum { }; enum { + SD_MAX_WS10_BLOCKS = 0xffff, + SD_MAX_WS16_BLOCKS = 0x7fffff, +}; + +enum { SD_LBP_FULL = 0, /* Full logical block provisioning */ SD_LBP_UNMAP, /* Use UNMAP command */ SD_LBP_WS16, /* Use WRITE SAME(16) with UNMAP bit */ @@ -77,6 +83,7 @@ struct scsi_disk { unsigned lbpws : 1; unsigned lbpws10 : 1; unsigned lbpvpd : 1; + unsigned ws16 : 1; }; #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev) |