@@ -47,6 +47,7 @@
#include <linux/blkpg.h>
#include <linux/blk-pm.h>
#include <linux/delay.h>
+#include <linux/rw_hint.h>
#include <linux/major.h>
#include <linux/mutex.h>
#include <linux/string_helpers.h>
@@ -1080,12 +1081,38 @@ static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
return BLK_STS_OK;
}
+/**
+ * sd_group_number() - Compute the GROUP NUMBER field
+ * @cmd: SCSI command for which to compute the value of the six-bit GROUP NUMBER
+ * field.
+ *
+ * From SBC-5 r05 (https://www.t10.org/cgi-bin/ac.pl?t=f&f=sbc5r05.pdf):
+ * 0: no relative lifetime.
+ * 1: shortest relative lifetime.
+ * 2: second shortest relative lifetime.
+ * 3 - 0x3d: intermediate relative lifetimes.
+ * 0x3e: second longest relative lifetime.
+ * 0x3f: longest relative lifetime.
+ */
+static u8 sd_group_number(struct scsi_cmnd *cmd)
+{
+ const struct request *rq = scsi_cmd_to_rq(cmd);
+ struct scsi_disk *sdkp = scsi_disk(rq->q->disk);
+
+ if (!sdkp->rscs)
+ return 0;
+
+ return min3((u32)rq->write_hint, (u32)sdkp->permanent_stream_count,
+ 0x3fu);
+}
+
static blk_status_t sd_setup_rw32_cmnd(struct scsi_cmnd *cmd, bool write,
sector_t lba, unsigned int nr_blocks,
unsigned char flags, unsigned int dld)
{
cmd->cmd_len = SD_EXT_CDB_SIZE;
cmd->cmnd[0] = VARIABLE_LENGTH_CMD;
+ cmd->cmnd[6] = sd_group_number(cmd);
cmd->cmnd[7] = 0x18; /* Additional CDB len */
cmd->cmnd[9] = write ? WRITE_32 : READ_32;
cmd->cmnd[10] = flags;
@@ -1104,7 +1131,7 @@ static blk_status_t sd_setup_rw16_cmnd(struct scsi_cmnd *cmd, bool write,
cmd->cmd_len = 16;
cmd->cmnd[0] = write ? WRITE_16 : READ_16;
cmd->cmnd[1] = flags | ((dld >> 2) & 0x01);
- cmd->cmnd[14] = (dld & 0x03) << 6;
+ cmd->cmnd[14] = ((dld & 0x03) << 6) | sd_group_number(cmd);
cmd->cmnd[15] = 0;
put_unaligned_be64(lba, &cmd->cmnd[2]);
put_unaligned_be32(nr_blocks, &cmd->cmnd[10]);
@@ -1119,7 +1146,7 @@ static blk_status_t sd_setup_rw10_cmnd(struct scsi_cmnd *cmd, bool write,
cmd->cmd_len = 10;
cmd->cmnd[0] = write ? WRITE_10 : READ_10;
cmd->cmnd[1] = flags;
- cmd->cmnd[6] = 0;
+ cmd->cmnd[6] = sd_group_number(cmd);
cmd->cmnd[9] = 0;
put_unaligned_be32(lba, &cmd->cmnd[2]);
put_unaligned_be16(nr_blocks, &cmd->cmnd[7]);
@@ -1256,7 +1283,7 @@ static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *cmd)
ret = sd_setup_rw16_cmnd(cmd, write, lba, nr_blocks,
protect | fua, dld);
} else if ((nr_blocks > 0xff) || (lba > 0x1fffff) ||
- sdp->use_10_for_rw || protect) {
+ sdp->use_10_for_rw || protect || rq->write_hint) {
ret = sd_setup_rw10_cmnd(cmd, write, lba, nr_blocks,
protect | fua);
} else {
@@ -3001,6 +3028,70 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
sdkp->DPOFUA = 0;
}
+static bool sd_is_perm_stream(struct scsi_disk *sdkp, unsigned int stream_id)
+{
+ u8 cdb[16] = { SERVICE_ACTION_IN_16, SAI_GET_STREAM_STATUS };
+ struct {
+ struct scsi_stream_status_header h;
+ struct scsi_stream_status s;
+ } buf;
+ struct scsi_device *sdev = sdkp->device;
+ struct scsi_sense_hdr sshdr;
+ const struct scsi_exec_args exec_args = {
+ .sshdr = &sshdr,
+ };
+ int res;
+
+ put_unaligned_be16(stream_id, &cdb[4]);
+ put_unaligned_be32(sizeof(buf), &cdb[10]);
+
+ res = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, &buf, sizeof(buf),
+ SD_TIMEOUT, sdkp->max_retries, &exec_args);
+ if (res < 0)
+ return false;
+ if (scsi_status_is_check_condition(res) && scsi_sense_valid(&sshdr))
+ sd_print_sense_hdr(sdkp, &sshdr);
+ if (res)
+ return false;
+ if (get_unaligned_be32(&buf.h.len) < sizeof(struct scsi_stream_status))
+ return false;
+ return buf.h.stream_status[0].perm;
+}
+
+static void sd_read_io_hints(struct scsi_disk *sdkp, unsigned char *buffer)
+{
+ struct scsi_device *sdp = sdkp->device;
+ const struct scsi_io_group_descriptor *desc, *start, *end;
+ struct scsi_sense_hdr sshdr;
+ struct scsi_mode_data data;
+ int res;
+
+ res = scsi_mode_sense(sdp, /*dbd=*/0x8, /*modepage=*/0x0a,
+ /*subpage=*/0x05, buffer, SD_BUF_SIZE,
+ SD_TIMEOUT, sdkp->max_retries, &data, &sshdr);
+ if (res < 0)
+ return;
+ start = (void *)buffer + data.header_length + 16;
+ end = (void *)buffer + ALIGN_DOWN(data.header_length + data.length,
+ sizeof(*end));
+ /*
+ * From "SBC-5 Constrained Streams with Data Lifetimes": Device severs
+ * should assign the lowest numbered stream identifiers to permanent
+ * streams.
+ */
+ for (desc = start; desc < end; desc++)
+ if (!desc->st_enble || !sd_is_perm_stream(sdkp, desc - start))
+ break;
+ sdkp->permanent_stream_count = desc - start;
+ if (sdkp->rscs && sdkp->permanent_stream_count < 2)
+ sd_printk(KERN_INFO, sdkp,
+ "Unexpected: RSCS has been set and the permanent stream count is %u\n",
+ sdkp->permanent_stream_count);
+ else if (sdkp->permanent_stream_count)
+ sd_printk(KERN_INFO, sdkp, "permanent stream count = %d\n",
+ sdkp->permanent_stream_count);
+}
+
/*
* The ATO bit indicates whether the DIF application tag is available
* for use by the operating system.
@@ -3484,6 +3575,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
sd_read_write_protect_flag(sdkp, buffer);
sd_read_cache_type(sdkp, buffer);
+ sd_read_io_hints(sdkp, buffer);
sd_read_app_tag_own(sdkp, buffer);
sd_read_write_same(sdkp, buffer);
sd_read_security(sdkp, buffer);
@@ -125,6 +125,8 @@ struct scsi_disk {
unsigned int physical_block_size;
unsigned int max_medium_access_timeouts;
unsigned int medium_access_timed_out;
+ /* number of permanent streams */
+ u16 permanent_stream_count;
u8 media_present;
u8 write_prot;
u8 protection_type;/* Data Integrity Field */
Recently T10 standardized SBC constrained streams. This mechanism allows to pass data lifetime information to SCSI devices in the group number field. Add support for translating write hint information into a permanent stream number in the sd driver. Use WRITE(10) instead of WRITE(6) if data lifetime information is present because the WRITE(6) command does not have a GROUP NUMBER field. Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/sd.c | 98 +++++++++++++++++++++++++++++++++++++++++++++-- drivers/scsi/sd.h | 2 + 2 files changed, 97 insertions(+), 3 deletions(-)