This uses a vendor specific command to pass the ATA TRIM payload to
libata without having to rewrite it in place. Support for it is
indicated by a new flag in struct scsi_device that libata will set
in it's slave_configure routine. A second flag indicates if TRIM
will reliably zero data.
Signed-off-by: Christoph Hellwig <h...@lst.de>
---
drivers/scsi/sd.c | 60 +++++++++++++++++++++++++++++++++++++++++++---
drivers/scsi/sd.h | 1 +
include/scsi/scsi_device.h | 2 ++
include/scsi/scsi_proto.h | 3 +++
4 files changed, 63 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index b853f91fb3da..cc8684818305 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -371,6 +371,7 @@ static const char *lbp_mode[] = {
[SD_LBP_WS16] = "writesame_16",
[SD_LBP_WS10] = "writesame_10",
[SD_LBP_ZERO] = "writesame_zero",
+ [SD_LBP_ATA_TRIM] = "ata_trim",
[SD_LBP_DISABLE] = "disabled",
};
@@ -411,7 +412,7 @@ provisioning_mode_store(struct device *dev, struct
device_attribute *attr,
sd_config_discard(sdkp, SD_LBP_ZERO);
else if (!strncmp(buf, lbp_mode[SD_LBP_DISABLE], 20))
sd_config_discard(sdkp, SD_LBP_DISABLE);
- else
+ else /* we don't allow manual setting of SD_LBP_ATA_TRIM */
return -EINVAL;
return count;
@@ -653,7 +654,7 @@ static void sd_config_discard(struct scsi_disk *sdkp,
unsigned int mode)
* lead to data corruption. If LBPRZ is not set, we honor the
* device preference.
*/
- if (sdkp->lbprz) {
+ if (sdkp->lbprz || sdkp->device->ata_trim) {
q->limits.discard_alignment = 0;
q->limits.discard_granularity = logical_block_size;
} else {
@@ -695,6 +696,12 @@ static void sd_config_discard(struct scsi_disk *sdkp,
unsigned int mode)
(u32)SD_MAX_WS10_BLOCKS);
q->limits.discard_zeroes_data = 1;
break;
+
+ case SD_LBP_ATA_TRIM:
+ max_blocks = 65535 * (512 / sizeof(__le64));
+ if (sdkp->device->ata_trim_zeroes_data)
+ q->limits.discard_zeroes_data = 1;
+ break;
}
blk_queue_max_discard_sectors(q, max_blocks * (logical_block_size >>
9));
@@ -794,6 +801,49 @@ static int sd_setup_write_same10_cmnd(struct scsi_cmnd
*cmd, bool unmap)
return scsi_init_io(cmd);
}
+static int sd_setup_ata_trim_cmnd(struct scsi_cmnd *cmd)
+{
+ struct scsi_device *sdp = cmd->device;
+ struct request *rq = cmd->request;
+ u64 sector = blk_rq_pos(rq) >> (ilog2(sdp->sector_size) - 9);
+ u32 nr_sectors = blk_rq_sectors(rq) >> (ilog2(sdp->sector_size) - 9);
+ u32 data_len = sdp->sector_size, i;
+ __le64 *buf;
+
+ rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
+ if (!rq->special_vec.bv_page)
+ return BLKPREP_DEFER;
+ rq->special_vec.bv_offset = 0;
+ rq->special_vec.bv_len = data_len;
+ rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
+
+ /*
+ * Use the Linux Vendor Specific TRIM command to pass the TRIM payload
+ * to libata.
+ */
+ cmd->cmd_len = 10;
+ cmd->cmnd[0] = LINUX_VS_TRIM;
+ cmd->cmnd[8] = data_len;
+
+ buf = page_address(rq->special_vec.bv_page);
+ for (i = 0; i < (data_len >> 3); i++) {
+ u64 n = min(nr_sectors, 0xffffu);
+
+ buf[i] = cpu_to_le64(sector | (n << 48));
+ if (nr_sectors <= 0xffff)
+ break;
+ sector += 0xffff;
+ nr_sectors -= 0xffff;
+ }
+
+ cmd->allowed = SD_MAX_RETRIES;
+ cmd->transfersize = data_len;
+ rq->timeout = SD_TIMEOUT;
+ scsi_req(rq)->resid_len = data_len;
+
+ return scsi_init_io(cmd);
+}
+
static void sd_config_write_same(struct scsi_disk *sdkp)
{
struct request_queue *q = sdkp->disk->queue;
@@ -1168,6 +1218,8 @@ static int sd_init_command(struct scsi_cmnd *cmd)
return sd_setup_write_same10_cmnd(cmd, true);
case SD_LBP_ZERO:
return sd_setup_write_same10_cmnd(cmd, false);
+ case SD_LBP_ATA_TRIM:
+ return sd_setup_ata_trim_cmnd(cmd);
default:
return BLKPREP_INVALID;
}
@@ -2739,7 +2791,9 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
sdkp->max_xfer_blocks = get_unaligned_be32(&buffer[8]);
sdkp->opt_xfer_blocks = get_unaligned_be32(&buffer[12]);
- if (buffer[3] == 0x3c) {
+ if (sdkp->device->ata_trim) {
+ sd_config_discard(sdkp, SD_LBP_ATA_TRIM);
+ } else if (buffer[3] == 0x3c) {
unsigned int lba_count, desc_count;
sdkp->max_ws_blocks = (u32)get_unaligned_be64(&buffer[36]);
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 4dac35e96a75..711d48cea5d7 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -56,6 +56,7 @@ enum {
SD_LBP_WS16, /* Use WRITE SAME(16) with UNMAP bit */
SD_LBP_WS10, /* Use WRITE SAME(10) with UNMAP bit */
SD_LBP_ZERO, /* Use WRITE SAME(10) with zero payload */
+ SD_LBP_ATA_TRIM, /* generate a ATA TRIM payload for libata */
SD_LBP_DISABLE, /* Discard disabled due to failed cmd */
};
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 080c7ce9bae8..7b1450b1b130 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -182,6 +182,8 @@ struct scsi_device {
unsigned broken_fua:1; /* Don't set FUA bit */
unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */
unsigned synchronous_alua:1; /* Synchronous ALUA commands */
+ unsigned ata_trim:1; /* use ATA TRIM payload for discard */
+ unsigned ata_trim_zeroes_data:1;/* ATA TRIM zeroes discard blocks */
atomic_t disk_events_disable_depth; /* disable depth for disk events */
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index 6ba66e01f6df..033b5662a5f5 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -169,6 +169,9 @@
/* Vendor specific CDBs start here */
#define VENDOR_SPECIFIC_CDB 0xc0
+/* used to pass the TRIM payload to libata with rewriting it: */
+#define LINUX_VS_TRIM VENDOR_SPECIFIC_CDB
+
/*
* SCSI command lengths
*/
--
2.11.0
