From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch updates usr/bs_sg.c:bs_sg_cmd_submit() to process incoming scsi-generic IO
of type SG_DXFER_TO_DEV and SG_DXFER_FROM_DEV using a single new struct scsi_cmnd->sg_iovec
set using existing scsi_cmd.h scsi_get_[out,in]_[buffer,length]() macros.
It also makes set_cmd_failed() properly return SAM_STAT_CHECK_CONDITION, which is expected
by the bs_sg_cmd_submit() caller in usr/scsi.c:scsi_cmd_perform()
Finally, this patch adds struct backingstore_template->bs_passthrough=1 that is used by
bs_sg.c here and the next patch to hand off struct scsi_cmd for CDB passthrough.
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
usr/bs_sg.c | 31 ++++++++++++++++++++++++-------
usr/scsi_cmnd.h | 4 ++++
usr/tgtd.h | 1 +
3 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/usr/bs_sg.c b/usr/bs_sg.c
index 8baa480..9696392 100644
--- a/usr/bs_sg.c
+++ b/usr/bs_sg.c
@@ -82,7 +82,7 @@ static int graceful_write(int fd, void *p_write, int to_write)
return 0;
}
-static void set_cmd_failed(struct scsi_cmd *cmd)
+static int set_cmd_failed(struct scsi_cmd *cmd)
{
int result = SAM_STAT_CHECK_CONDITION;
uint16_t asc = ASC_READ_ERROR;
@@ -90,11 +90,14 @@ static void set_cmd_failed(struct scsi_cmd *cmd)
scsi_set_result(cmd, result);
sense_data_build(cmd, key, asc);
+
+ return result;
}
static int bs_sg_cmd_submit(struct scsi_cmd *cmd)
{
struct scsi_lu *dev = cmd->dev;
+ struct sg_iovec *iov = &cmd->sg_iovec;
int fd = dev->fd;
struct sg_io_hdr io_hdr;
int err = 0;
@@ -104,14 +107,27 @@ static int bs_sg_cmd_submit(struct scsi_cmd *cmd)
io_hdr.cmd_len = cmd->scb_len;
io_hdr.cmdp = cmd->scb;
+ if (scsi_get_data_dir(cmd) == DATA_BIDIRECTIONAL) {
+ eprintf("Unable to process DATA_BIDIRECTIONAL to"
+ " SG_IO backstore\n");
+ return set_cmd_failed(cmd);
+ }
+
if (scsi_get_data_dir(cmd) == DATA_WRITE) {
io_hdr.dxfer_direction = SG_DXFER_TO_DEV;
- io_hdr.dxfer_len = scsi_get_out_length(cmd);
- io_hdr.dxferp = (void *)scsi_get_out_buffer(cmd);
- } else {
+ io_hdr.dxfer_len = iov->iov_len = scsi_get_out_length(cmd);
+ iov->iov_base = (void *)scsi_get_out_buffer(cmd);
+ io_hdr.dxferp = &cmd->sg_iovec;
+ io_hdr.iovec_count = 1;
+ } else if (scsi_get_data_dir(cmd) == DATA_READ) {
io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
- io_hdr.dxfer_len = scsi_get_in_length(cmd);
- io_hdr.dxferp = (void *)scsi_get_in_buffer(cmd);
+ io_hdr.dxfer_len = iov->iov_len = scsi_get_in_length(cmd);
+ iov->iov_base = (void *)scsi_get_in_buffer(cmd);
+ io_hdr.dxferp = &cmd->sg_iovec;
+ io_hdr.iovec_count = 1;
+ } else {
+ io_hdr.dxfer_direction = SG_DXFER_NONE;
+ io_hdr.dxfer_len = 0;
}
io_hdr.mx_sb_len = sizeof(cmd->sense_buffer);
io_hdr.sbp = cmd->sense_buffer;
@@ -125,7 +141,7 @@ static int bs_sg_cmd_submit(struct scsi_cmd *cmd)
set_cmd_async(cmd);
else {
eprintf("failed to start cmd 0x%p\n", cmd);
- set_cmd_failed(cmd);
+ return set_cmd_failed(cmd);
}
return 0;
}
@@ -238,6 +254,7 @@ static int bs_sg_cmd_done(struct scsi_cmd *cmd)
static struct backingstore_template sg_bst = {
.bs_name = "sg",
.bs_datasize = 0,
+ .bs_passthrough = 1,
.bs_open = bs_sg_open,
.bs_close = bs_sg_close,
.bs_cmd_submit = bs_sg_cmd_submit,
diff --git a/usr/scsi_cmnd.h b/usr/scsi_cmnd.h
index 011f3e6..776ffb3 100644
--- a/usr/scsi_cmnd.h
+++ b/usr/scsi_cmnd.h
@@ -17,6 +17,8 @@ struct scsi_data_buffer {
uint64_t buffer;
};
+#include <scsi/sg.h>
+
struct scsi_cmd {
struct target *c_target;
/* linked it_nexus->cmd_hash_list */
@@ -31,6 +33,8 @@ struct scsi_cmd {
enum data_direction data_dir;
struct scsi_data_buffer in_sdb;
struct scsi_data_buffer out_sdb;
+ /* used for bs_sg.c:bs_sg_cmd_submit() */
+ struct sg_iovec sg_iovec;
uint64_t cmd_itn_id;
uint64_t offset;
diff --git a/usr/tgtd.h b/usr/tgtd.h
index 3323a9b..4f26a29 100644
--- a/usr/tgtd.h
+++ b/usr/tgtd.h
@@ -117,6 +117,7 @@ struct device_type_template {
struct backingstore_template {
const char *bs_name;
int bs_datasize;
+ int bs_passthrough;
int (*bs_open)(struct scsi_lu *dev, char *path, int *fd, uint64_t *size);
void (*bs_close)(struct scsi_lu *dev);
int (*bs_init)(struct scsi_lu *dev);
--
1.5.6.5
--
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