In case SCSI command states SCSI_PROT_READ_STRIP or
SCSI_PROT_WRITE_GENERATE loopback should follow it
by allocating protection scatterlist and generate
protection information if needed.
Signed-off-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
drivers/target/loopback/tcm_loop.c | 81 ++++++++++++++++++++++++++++++++
drivers/target/target_core_transport.c | 1 +
include/target/target_core_backend.h | 1 -
include/target/target_core_base.h | 2 +
4 files changed, 84 insertions(+), 1 deletions(-)
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index fadad7c..a581ff3 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -31,6 +31,7 @@
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
+#include <linux/crc-t10dif.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
@@ -169,6 +170,51 @@ static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
return MSG_SIMPLE_TAG;
}
+static void tcm_loop_calc_dif(void *data, sector_t sector, u32 sector_size,
+ struct se_dif_v1_tuple *sdt)
+{
+ sdt->guard_tag = cpu_to_be16(crc_t10dif(data, sector_size));
+ sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
+ sdt->app_tag = 0;
+}
+
+static void tcm_loop_generate_dif(struct se_cmd *cmd, sector_t sector,
+ u32 sector_size)
+{
+ struct se_dif_v1_tuple *sdt;
+ struct scatterlist *dsg, *psg = cmd->t_prot_sg;
+ void *daddr, *paddr;
+ int i, j, offset = 0;
+
+ for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
+
+ daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
+ paddr = kmap_atomic(sg_page(psg)) + psg->offset;
+ for (j = 0; j < dsg->length; j += sector_size) {
+
+ if (offset >= psg->length) {
+ kunmap_atomic(paddr);
+ psg = sg_next(psg);
+ paddr = kmap_atomic(sg_page(psg)) + psg->offset;
+ offset = 0;
+ }
+
+ sdt = paddr + offset;
+ tcm_loop_calc_dif(daddr + j, sector, sector_size, sdt);
+
+ pr_debug("DIF sector: %llu guard_tag: 0x%04x"
+ " app_tag: 0x%04x ref_tag: %u\n",
+ (unsigned long long)sector, sdt->guard_tag,
+ sdt->app_tag, be32_to_cpu(sdt->ref_tag));
+
+ sector++;
+ offset += sizeof(struct se_dif_v1_tuple);
+ }
+ kunmap_atomic(paddr);
+ kunmap_atomic(daddr);
+ }
+}
+
static void tcm_loop_submission_work(struct work_struct *work)
{
struct tcm_loop_cmd *tl_cmd =
@@ -181,6 +227,7 @@ static void tcm_loop_submission_work(struct work_struct *work)
struct scatterlist *sgl_bidi = NULL;
u32 sgl_bidi_count = 0;
int rc;
+ u32 prot_len;
tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
@@ -212,6 +259,40 @@ static void tcm_loop_submission_work(struct work_struct *work)
se_cmd->se_cmd_flags |= SCF_BIDI;
}
+
+ if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL) {
+ prot_len = scsi_bufflen(sc) * sizeof(struct se_dif_v1_tuple);
+ do_div(prot_len, sc->device->sector_size);
+ }
+
+ switch (scsi_get_prot_op(sc)) {
+ case SCSI_PROT_READ_STRIP:
+ rc = target_alloc_sgl(&se_cmd->t_prot_sg,
+ &se_cmd->t_prot_nents,
+ prot_len, true);
+ if (rc < 0) {
+ pr_err("Failed to allocate protection, returning...\n");
+ return;
+ }
+ break;
+ case SCSI_PROT_WRITE_INSERT:
+ rc = target_alloc_sgl(&se_cmd->t_prot_sg,
+ &se_cmd->t_prot_nents,
+ prot_len, true);
+ if (rc < 0) {
+ pr_err("Failed to allocate protection, returning...\n");
+ return;
+ }
+ tcm_loop_generate_dif(se_cmd, scsi_get_lba(sc) & 0xffffffff,
+ sc->device->sector_size);
+ break;
+ case SCSI_PROT_READ_PASS:
+ case SCSI_PROT_WRITE_PASS:
+ case SCSI_PROT_NORMAL:
+ default:
+ break;
+ }
+
rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
scsi_bufflen(sc), tcm_loop_sam_attr(sc),
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index fb7fac5..ed84783 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2184,6 +2184,7 @@ out:
kfree(sg);
return -ENOMEM;
}
+EXPORT_SYMBOL(target_alloc_sgl);
/*
* Allocate any required resources to execute the command. For writes we
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 7020e33..0eabeab 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -87,7 +87,6 @@ int transport_set_vpd_ident(struct t10_vpd *, unsigned char *);
void *transport_kmap_data_sg(struct se_cmd *);
void transport_kunmap_data_sg(struct se_cmd *);
/* core helpers also used by xcopy during internal command setup */
-int target_alloc_sgl(struct scatterlist **, unsigned int *, u32, bool);
sense_reason_t transport_generic_map_mem_to_cmd(struct se_cmd *,
struct scatterlist *, u32, struct scatterlist *, u32);
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 344fd05..6aa3a17 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -897,4 +897,6 @@ struct se_wwn {
struct config_group fabric_stat_group;
};
+int target_alloc_sgl(struct scatterlist **, unsigned int *, u32, bool);
+
#endif /* TARGET_CORE_BASE_H */
--
1.7.1
--
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