linux/drivers/scsi/scsi_trace.c
John Garry bf4ae8f2e6 scsi: sd: Atomic write support
Support is divided into two main areas:
- reading VPD pages and setting sdev request_queue limits
- support WRITE ATOMIC (16) command and tracing

The relevant block limits VPD page need to be read to allow the block layer
request_queue atomic write limits to be set. These VPD page limits are
described in sbc4r22 section 6.6.4 - Block limits VPD page.

There are five limits of interest:
- MAXIMUM ATOMIC TRANSFER LENGTH
- ATOMIC ALIGNMENT
- ATOMIC TRANSFER LENGTH GRANULARITY
- MAXIMUM ATOMIC TRANSFER LENGTH WITH BOUNDARY
- MAXIMUM ATOMIC BOUNDARY SIZE

MAXIMUM ATOMIC TRANSFER LENGTH is the maximum length for a WRITE ATOMIC
(16) command. It will not be greater than the device MAXIMUM TRANSFER
LENGTH.

ATOMIC ALIGNMENT and ATOMIC TRANSFER LENGTH GRANULARITY are the minimum
alignment and length values for an atomic write in terms of logical blocks.

Unlike NVMe, SCSI does not specify an LBA space boundary, but does specify
a per-IO boundary granularity. The maximum boundary size is specified in
MAXIMUM ATOMIC BOUNDARY SIZE. When used, this boundary value is set in the
WRITE ATOMIC (16) ATOMIC BOUNDARY field - layout for the WRITE_ATOMIC_16
command can be found in sbc4r22 section 5.48. This boundary value is the
granularity size at which the device may atomically write the data. A value
of zero in WRITE ATOMIC (16) ATOMIC BOUNDARY field means that all data must
be atomically written together.

MAXIMUM ATOMIC TRANSFER LENGTH WITH BOUNDARY is the maximum atomic write
length if a non-zero boundary value is set.

For atomic write support, the WRITE ATOMIC (16) boundary is not of much
interest, as the block layer expects each request submitted to be executed
atomically. However, the SCSI spec does leave itself open to a quirky
scenario where MAXIMUM ATOMIC TRANSFER LENGTH is zero, yet MAXIMUM ATOMIC
TRANSFER LENGTH WITH BOUNDARY and MAXIMUM ATOMIC BOUNDARY SIZE are both
non-zero. This case will be supported.

To set the block layer request_queue atomic write capabilities, sanitize
the VPD page limits and set limits as follows:
- atomic_write_unit_min is derived from granularity and alignment values.
  If no granularity value is not set, use physical block size
- atomic_write_unit_max is derived from MAXIMUM ATOMIC TRANSFER LENGTH. In
  the scenario where MAXIMUM ATOMIC TRANSFER LENGTH is zero and boundary
  limits are non-zero, use MAXIMUM ATOMIC BOUNDARY SIZE for
  atomic_write_unit_max. New flag scsi_disk.use_atomic_write_boundary is
  set for this scenario.
- atomic_write_boundary_bytes is set to zero always

SCSI also supports a WRITE ATOMIC (32) command, which is for type 2
protection enabled. This is not going to be supported now, so check for
T10_PI_TYPE2_PROTECTION when setting any request_queue limits.

To handle an atomic write request, add support for WRITE ATOMIC (16)
command in handler sd_setup_atomic_cmnd(). Flag use_atomic_write_boundary
is checked here for encoding ATOMIC BOUNDARY field.

Trace info is also added for WRITE_ATOMIC_16 command.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20240620125359.2684798-9-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-20 15:19:17 -06:00

414 lines
8.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2010 FUJITSU LIMITED
* Copyright (C) 2010 Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com>
*/
#include <linux/kernel.h>
#include <linux/trace_seq.h>
#include <asm/unaligned.h>
#include <trace/events/scsi.h>
#define SERVICE_ACTION16(cdb) (cdb[1] & 0x1f)
#define SERVICE_ACTION32(cdb) (get_unaligned_be16(&cdb[8]))
static const char *
scsi_trace_misc(struct trace_seq *, unsigned char *, int);
static const char *
scsi_trace_rw6(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
u32 lba, txlen;
lba = get_unaligned_be24(&cdb[1]) & 0x1fffff;
/*
* From SBC-2: a TRANSFER LENGTH field set to zero specifies that 256
* logical blocks shall be read (READ(6)) or written (WRITE(6)).
*/
txlen = cdb[4] ? cdb[4] : 256;
trace_seq_printf(p, "lba=%u txlen=%u", lba, txlen);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_rw10(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
u32 lba, txlen;
lba = get_unaligned_be32(&cdb[2]);
txlen = get_unaligned_be16(&cdb[7]);
trace_seq_printf(p, "lba=%u txlen=%u protect=%u", lba, txlen,
cdb[1] >> 5);
if (cdb[0] == WRITE_SAME)
trace_seq_printf(p, " unmap=%u", cdb[1] >> 3 & 1);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_rw12(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
u32 lba, txlen;
lba = get_unaligned_be32(&cdb[2]);
txlen = get_unaligned_be32(&cdb[6]);
trace_seq_printf(p, "lba=%u txlen=%u protect=%u", lba, txlen,
cdb[1] >> 5);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_rw16(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
u64 lba;
u32 txlen;
lba = get_unaligned_be64(&cdb[2]);
txlen = get_unaligned_be32(&cdb[10]);
trace_seq_printf(p, "lba=%llu txlen=%u protect=%u", lba, txlen,
cdb[1] >> 5);
if (cdb[0] == WRITE_SAME_16)
trace_seq_printf(p, " unmap=%u", cdb[1] >> 3 & 1);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_rw32(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u64 lba;
u32 ei_lbrt, txlen;
switch (SERVICE_ACTION32(cdb)) {
case READ_32:
cmd = "READ";
break;
case VERIFY_32:
cmd = "VERIFY";
break;
case WRITE_32:
cmd = "WRITE";
break;
case WRITE_SAME_32:
cmd = "WRITE_SAME";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
lba = get_unaligned_be64(&cdb[12]);
ei_lbrt = get_unaligned_be32(&cdb[20]);
txlen = get_unaligned_be32(&cdb[28]);
trace_seq_printf(p, "%s_32 lba=%llu txlen=%u protect=%u ei_lbrt=%u",
cmd, lba, txlen, cdb[10] >> 5, ei_lbrt);
if (SERVICE_ACTION32(cdb) == WRITE_SAME_32)
trace_seq_printf(p, " unmap=%u", cdb[10] >> 3 & 1);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_unmap(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
unsigned int regions = get_unaligned_be16(&cdb[7]);
trace_seq_printf(p, "regions=%u", (regions - 8) / 16);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_service_action_in(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u64 lba;
u32 alloc_len;
switch (SERVICE_ACTION16(cdb)) {
case SAI_READ_CAPACITY_16:
cmd = "READ_CAPACITY_16";
break;
case SAI_GET_LBA_STATUS:
cmd = "GET_LBA_STATUS";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
lba = get_unaligned_be64(&cdb[2]);
alloc_len = get_unaligned_be32(&cdb[10]);
trace_seq_printf(p, "%s lba=%llu alloc_len=%u", cmd, lba, alloc_len);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_maintenance_in(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u32 alloc_len;
switch (SERVICE_ACTION16(cdb)) {
case MI_REPORT_IDENTIFYING_INFORMATION:
cmd = "REPORT_IDENTIFYING_INFORMATION";
break;
case MI_REPORT_TARGET_PGS:
cmd = "REPORT_TARGET_PORT_GROUPS";
break;
case MI_REPORT_ALIASES:
cmd = "REPORT_ALIASES";
break;
case MI_REPORT_SUPPORTED_OPERATION_CODES:
cmd = "REPORT_SUPPORTED_OPERATION_CODES";
break;
case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
cmd = "REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS";
break;
case MI_REPORT_PRIORITY:
cmd = "REPORT_PRIORITY";
break;
case MI_REPORT_TIMESTAMP:
cmd = "REPORT_TIMESTAMP";
break;
case MI_MANAGEMENT_PROTOCOL_IN:
cmd = "MANAGEMENT_PROTOCOL_IN";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
alloc_len = get_unaligned_be32(&cdb[6]);
trace_seq_printf(p, "%s alloc_len=%u", cmd, alloc_len);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_maintenance_out(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u32 alloc_len;
switch (SERVICE_ACTION16(cdb)) {
case MO_SET_IDENTIFYING_INFORMATION:
cmd = "SET_IDENTIFYING_INFORMATION";
break;
case MO_SET_TARGET_PGS:
cmd = "SET_TARGET_PORT_GROUPS";
break;
case MO_CHANGE_ALIASES:
cmd = "CHANGE_ALIASES";
break;
case MO_SET_PRIORITY:
cmd = "SET_PRIORITY";
break;
case MO_SET_TIMESTAMP:
cmd = "SET_TIMESTAMP";
break;
case MO_MANAGEMENT_PROTOCOL_OUT:
cmd = "MANAGEMENT_PROTOCOL_OUT";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
alloc_len = get_unaligned_be32(&cdb[6]);
trace_seq_printf(p, "%s alloc_len=%u", cmd, alloc_len);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_zbc_in(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u64 zone_id;
u32 alloc_len;
u8 options;
switch (SERVICE_ACTION16(cdb)) {
case ZI_REPORT_ZONES:
cmd = "REPORT_ZONES";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
zone_id = get_unaligned_be64(&cdb[2]);
alloc_len = get_unaligned_be32(&cdb[10]);
options = cdb[14] & 0x3f;
trace_seq_printf(p, "%s zone=%llu alloc_len=%u options=%u partial=%u",
cmd, (unsigned long long)zone_id, alloc_len,
options, (cdb[14] >> 7) & 1);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_zbc_out(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p), *cmd;
u64 zone_id;
switch (SERVICE_ACTION16(cdb)) {
case ZO_CLOSE_ZONE:
cmd = "CLOSE_ZONE";
break;
case ZO_FINISH_ZONE:
cmd = "FINISH_ZONE";
break;
case ZO_OPEN_ZONE:
cmd = "OPEN_ZONE";
break;
case ZO_RESET_WRITE_POINTER:
cmd = "RESET_WRITE_POINTER";
break;
default:
trace_seq_puts(p, "UNKNOWN");
goto out;
}
zone_id = get_unaligned_be64(&cdb[2]);
trace_seq_printf(p, "%s zone=%llu all=%u", cmd,
(unsigned long long)zone_id, cdb[14] & 1);
out:
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_atomic_write16_out(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
unsigned int boundary_size;
unsigned int nr_blocks;
sector_t lba;
lba = get_unaligned_be64(&cdb[2]);
boundary_size = get_unaligned_be16(&cdb[10]);
nr_blocks = get_unaligned_be16(&cdb[12]);
trace_seq_printf(p, "lba=%llu txlen=%u boundary_size=%u",
lba, nr_blocks, boundary_size);
trace_seq_putc(p, 0);
return ret;
}
static const char *
scsi_trace_varlen(struct trace_seq *p, unsigned char *cdb, int len)
{
switch (SERVICE_ACTION32(cdb)) {
case READ_32:
case VERIFY_32:
case WRITE_32:
case WRITE_SAME_32:
return scsi_trace_rw32(p, cdb, len);
default:
return scsi_trace_misc(p, cdb, len);
}
}
static const char *
scsi_trace_misc(struct trace_seq *p, unsigned char *cdb, int len)
{
const char *ret = trace_seq_buffer_ptr(p);
trace_seq_putc(p, '-');
trace_seq_putc(p, 0);
return ret;
}
const char *
scsi_trace_parse_cdb(struct trace_seq *p, unsigned char *cdb, int len)
{
switch (cdb[0]) {
case READ_6:
case WRITE_6:
return scsi_trace_rw6(p, cdb, len);
case READ_10:
case VERIFY:
case WRITE_10:
case WRITE_SAME:
return scsi_trace_rw10(p, cdb, len);
case READ_12:
case VERIFY_12:
case WRITE_12:
return scsi_trace_rw12(p, cdb, len);
case READ_16:
case VERIFY_16:
case WRITE_16:
case WRITE_SAME_16:
return scsi_trace_rw16(p, cdb, len);
case UNMAP:
return scsi_trace_unmap(p, cdb, len);
case SERVICE_ACTION_IN_16:
return scsi_trace_service_action_in(p, cdb, len);
case VARIABLE_LENGTH_CMD:
return scsi_trace_varlen(p, cdb, len);
case MAINTENANCE_IN:
return scsi_trace_maintenance_in(p, cdb, len);
case MAINTENANCE_OUT:
return scsi_trace_maintenance_out(p, cdb, len);
case ZBC_IN:
return scsi_trace_zbc_in(p, cdb, len);
case ZBC_OUT:
return scsi_trace_zbc_out(p, cdb, len);
case WRITE_ATOMIC_16:
return scsi_trace_atomic_write16_out(p, cdb, len);
default:
return scsi_trace_misc(p, cdb, len);
}
}