Skip to content

Commit

Permalink
scsi: scsi_debug: Implement support for write protect
Browse files Browse the repository at this point in the history 
Teach scsi_debug to honor SWP in the Control Mode Page and report the
resulting WP state in the Device-Specific Parameter field.

In check_device_access_params() verify that commands that will write
the medium are permitted to do so.

Signed-off-by: Martin K. Petersen <[email protected]>
Acked-by: Douglas Gilbert <[email protected]>
  • Loading branch information
@martinkpetersen
martinkpetersen committed Feb 12, 2019
1 parent 9fa505a commit 9447b6c
Showing 1 changed file with 31 additions and 45 deletions.
76 changes: 31 additions & 45 deletions drivers/scsi/scsi_debug.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,7 @@ static const char *sdebug_version_date = "20180128";
#define LBA_OUT_OF_RANGE 0x21
#define INVALID_FIELD_IN_CDB 0x24
#define INVALID_FIELD_IN_PARAM_LIST 0x26
#define WRITE_PROTECTED 0x27
#define UA_RESET_ASC 0x29
#define UA_CHANGED_ASC 0x2a
#define TARGET_CHANGED_ASC 0x3f
Expand Down Expand Up @@ -668,6 +669,7 @@ static bool sdebug_verbose;
static bool have_dif_prot;
static bool write_since_sync;
static bool sdebug_statistics = DEF_STATISTICS;
static bool sdebug_wp;

static unsigned int sdebug_store_sectors;
static sector_t sdebug_capacity; /* in sectors */
Expand Down Expand Up @@ -2143,9 +2145,11 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
target_dev_id = ((devip->sdbg_host->shost->host_no + 1) * 2000) +
(devip->target * 1000) - 3;
/* for disks set DPOFUA bit and clear write protect (WP) bit */
if (is_disk)
if (is_disk) {
dev_spec = 0x10; /* =0x90 if WP=1 implies read-only */
else
if (sdebug_wp)
dev_spec |= 0x80;
} else
dev_spec = 0x0;
if (msense_6) {
arr[2] = dev_spec;
Expand Down Expand Up @@ -2328,6 +2332,10 @@ static int resp_mode_select(struct scsi_cmnd *scp,
if (ctrl_m_pg[1] == arr[off + 1]) {
memcpy(ctrl_m_pg + 2, arr + off + 2,
sizeof(ctrl_m_pg) - 2);
if (ctrl_m_pg[4] & 0x8)
sdebug_wp = true;
else
sdebug_wp = false;
sdebug_dsense = !!(ctrl_m_pg[2] & 0x4);
goto set_mode_changed_ua;
}
Expand Down Expand Up @@ -2452,8 +2460,8 @@ static int resp_log_sense(struct scsi_cmnd *scp,
min(len, SDEBUG_MAX_INQ_ARR_SZ));
}

static int check_device_access_params(struct scsi_cmnd *scp,
unsigned long long lba, unsigned int num)
static inline int check_device_access_params(struct scsi_cmnd *scp,
unsigned long long lba, unsigned int num, bool write)
{
if (lba + num > sdebug_capacity) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
Expand All @@ -2465,6 +2473,10 @@ static int check_device_access_params(struct scsi_cmnd *scp,
mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
return check_condition_result;
}
if (write && unlikely(sdebug_wp)) {
mk_sense_buffer(scp, DATA_PROTECT, WRITE_PROTECTED, 0x2);
return check_condition_result;
}
return 0;
}

Expand Down Expand Up @@ -2723,18 +2735,9 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
} else
sqcp = NULL;

/* inline check_device_access_params() */
if (unlikely(lba + num > sdebug_capacity)) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
return check_condition_result;
}
/* transfer length excessive (tie in to block limits VPD page) */
if (unlikely(num > sdebug_store_sectors)) {
/* needs work to find which cdb byte 'num' comes from */
mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
return check_condition_result;
}

ret = check_device_access_params(scp, lba, num, false);
if (ret)
return ret;
if (unlikely((SDEBUG_OPT_MEDIUM_ERR & sdebug_opts) &&
(lba <= (sdebug_medium_error_start + sdebug_medium_error_count - 1)) &&
((lba + num) > sdebug_medium_error_start))) {
Expand Down Expand Up @@ -3026,19 +3029,9 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
sdev_printk(KERN_ERR, scp->device, "Unprotected WR "
"to DIF device\n");
}

/* inline check_device_access_params() */
if (unlikely(lba + num > sdebug_capacity)) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
return check_condition_result;
}
/* transfer length excessive (tie in to block limits VPD page) */
if (unlikely(num > sdebug_store_sectors)) {
/* needs work to find which cdb byte 'num' comes from */
mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
return check_condition_result;
}

ret = check_device_access_params(scp, lba, num, true);
if (ret)
return ret;
write_lock_irqsave(&atomic_rw, iflags);

/* DIX + T10 DIF */
Expand Down Expand Up @@ -3177,7 +3170,7 @@ static int resp_write_scat(struct scsi_cmnd *scp,
my_name, __func__, k, lba, num, sg_off);
if (num == 0)
continue;
ret = check_device_access_params(scp, lba, num);
ret = check_device_access_params(scp, lba, num, true);
if (ret)
goto err_out_unlock;
num_by = num * lb_size;
Expand Down Expand Up @@ -3261,7 +3254,7 @@ static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num,
int ret;
u64 lba_off;

ret = check_device_access_params(scp, lba, num);
ret = check_device_access_params(scp, lba, num, true);
if (ret)
return ret;

Expand Down Expand Up @@ -3434,18 +3427,9 @@ static int resp_comp_write(struct scsi_cmnd *scp,
(cmd[1] & 0xe0) == 0)
sdev_printk(KERN_ERR, scp->device, "Unprotected WR "
"to DIF device\n");

/* inline check_device_access_params() */
if (lba + num > sdebug_capacity) {
mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
return check_condition_result;
}
/* transfer length excessive (tie in to block limits VPD page) */
if (num > sdebug_store_sectors) {
/* needs work to find which cdb byte 'num' comes from */
mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
return check_condition_result;
}
ret = check_device_access_params(scp, lba, num, false);
if (ret)
return ret;
dnum = 2 * num;
arr = kcalloc(lb_size, dnum, GFP_ATOMIC);
if (NULL == arr) {
Expand Down Expand Up @@ -3528,7 +3512,7 @@ static int resp_unmap(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
unsigned long long lba = get_unaligned_be64(&desc[i].lba);
unsigned int num = get_unaligned_be32(&desc[i].blocks);

ret = check_device_access_params(scp, lba, num);
ret = check_device_access_params(scp, lba, num, true);
if (ret)
goto out;

Expand Down Expand Up @@ -3561,7 +3545,7 @@ static int resp_get_lba_status(struct scsi_cmnd *scp,
if (alloc_len < 24)
return 0;

ret = check_device_access_params(scp, lba, 1);
ret = check_device_access_params(scp, lba, 1, false);
if (ret)
return ret;

Expand Down Expand Up @@ -4485,6 +4469,7 @@ module_param_named(virtual_gb, sdebug_virtual_gb, int, S_IRUGO | S_IWUSR);
module_param_named(uuid_ctl, sdebug_uuid_ctl, int, S_IRUGO);
module_param_named(vpd_use_hostno, sdebug_vpd_use_hostno, int,
S_IRUGO | S_IWUSR);
module_param_named(wp, sdebug_wp, bool, S_IRUGO | S_IWUSR);
module_param_named(write_same_length, sdebug_write_same_length, int,
S_IRUGO | S_IWUSR);

Expand Down Expand Up @@ -4544,6 +4529,7 @@ MODULE_PARM_DESC(uuid_ctl,
"1->use uuid for lu name, 0->don't, 2->all use same (def=0)");
MODULE_PARM_DESC(virtual_gb, "virtual gigabyte (GiB) size (def=0 -> use dev_size_mb)");
MODULE_PARM_DESC(vpd_use_hostno, "0 -> dev ids ignore hostno (def=1 -> unique dev ids)");
MODULE_PARM_DESC(wp, "Write Protect (def=0)");
MODULE_PARM_DESC(write_same_length, "Maximum blocks per WRITE SAME cmd (def=0xffff)");

#define SDEBUG_INFO_LEN 256
Expand Down

0 comments on commit 9447b6c

Please sign in to comment.