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scsi: target: use the stack for XCOPY passthrough cmds
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Reads and writes in the XCOPY loop are synchronous, so needn't be heap
allocated / freed with each loop.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: David Disseldorp <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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@ddiss @martinkpetersen
ddiss authored and martinkpetersen committed Mar 29, 2020
1 parent 5f306af commit b92fcfc
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Showing 2 changed files with 31 additions and 58 deletions.
84 changes: 31 additions & 53 deletions drivers/target/target_core_xcopy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -410,7 +410,8 @@ static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
struct xcopy_pt_cmd, se_cmd);

kfree(xpt_cmd);
/* xpt_cmd is on the stack, nothing to free here */
pr_debug("xpt_cmd done: %p\n", xpt_cmd);
}

static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
Expand Down Expand Up @@ -566,20 +567,15 @@ static int target_xcopy_read_source(
sector_t src_lba,
u32 src_sectors)
{
struct xcopy_pt_cmd *xpt_cmd;
struct se_cmd *se_cmd;
struct xcopy_pt_cmd xpt_cmd;
struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
u32 length = (src_sectors * src_dev->dev_attrib.block_size);
int rc;
unsigned char cdb[16];
bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);

xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
if (!xpt_cmd) {
pr_err("Unable to allocate xcopy_pt_cmd\n");
return -ENOMEM;
}
init_completion(&xpt_cmd->xpt_passthrough_sem);
se_cmd = &xpt_cmd->se_cmd;
memset(&xpt_cmd, 0, sizeof(xpt_cmd));
init_completion(&xpt_cmd.xpt_passthrough_sem);

memset(&cdb[0], 0, 16);
cdb[0] = READ_16;
Expand All @@ -589,28 +585,24 @@ static int target_xcopy_read_source(
(unsigned long long)src_lba, src_sectors, length);

transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
DMA_FROM_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
xop->src_pt_cmd = xpt_cmd;
DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0]);

rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, src_dev, &cdb[0],
rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
remote_port);
if (rc < 0) {
ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
transport_generic_free_cmd(se_cmd, 0);
return rc;
ec_cmd->scsi_status = se_cmd->scsi_status;
goto out;
}

pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
" memory\n", xop->xop_data_sg, xop->xop_data_nents);

rc = target_xcopy_issue_pt_cmd(xpt_cmd);
if (rc < 0) {
ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
transport_generic_free_cmd(se_cmd, 0);
return rc;
}

return 0;
rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
if (rc < 0)
ec_cmd->scsi_status = se_cmd->scsi_status;
out:
transport_generic_free_cmd(se_cmd, 0);
return rc;
}

static int target_xcopy_write_destination(
Expand All @@ -620,20 +612,15 @@ static int target_xcopy_write_destination(
sector_t dst_lba,
u32 dst_sectors)
{
struct xcopy_pt_cmd *xpt_cmd;
struct se_cmd *se_cmd;
struct xcopy_pt_cmd xpt_cmd;
struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
u32 length = (dst_sectors * dst_dev->dev_attrib.block_size);
int rc;
unsigned char cdb[16];
bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);

xpt_cmd = kzalloc(sizeof(struct xcopy_pt_cmd), GFP_KERNEL);
if (!xpt_cmd) {
pr_err("Unable to allocate xcopy_pt_cmd\n");
return -ENOMEM;
}
init_completion(&xpt_cmd->xpt_passthrough_sem);
se_cmd = &xpt_cmd->se_cmd;
memset(&xpt_cmd, 0, sizeof(xpt_cmd));
init_completion(&xpt_cmd.xpt_passthrough_sem);

memset(&cdb[0], 0, 16);
cdb[0] = WRITE_16;
Expand All @@ -643,25 +630,21 @@ static int target_xcopy_write_destination(
(unsigned long long)dst_lba, dst_sectors, length);

transport_init_se_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
DMA_TO_DEVICE, 0, &xpt_cmd->sense_buffer[0]);
xop->dst_pt_cmd = xpt_cmd;
DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0]);

rc = target_xcopy_setup_pt_cmd(xpt_cmd, xop, dst_dev, &cdb[0],
rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
remote_port);
if (rc < 0) {
ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
transport_generic_free_cmd(se_cmd, 0);
return rc;
}

rc = target_xcopy_issue_pt_cmd(xpt_cmd);
if (rc < 0) {
ec_cmd->scsi_status = xpt_cmd->se_cmd.scsi_status;
transport_generic_free_cmd(se_cmd, 0);
return rc;
ec_cmd->scsi_status = se_cmd->scsi_status;
goto out;
}

return 0;
rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
if (rc < 0)
ec_cmd->scsi_status = se_cmd->scsi_status;
out:
transport_generic_free_cmd(se_cmd, 0);
return rc;
}

static void target_xcopy_do_work(struct work_struct *work)
Expand Down Expand Up @@ -736,20 +719,15 @@ static void target_xcopy_do_work(struct work_struct *work)

rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
dst_lba, cur_nolb);
if (rc < 0) {
transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
if (rc < 0)
goto out;
}

dst_lba += cur_nolb;
pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
(unsigned long long)dst_lba);

copied_nolb += cur_nolb;
nolb -= cur_nolb;

transport_generic_free_cmd(&xop->src_pt_cmd->se_cmd, 0);
transport_generic_free_cmd(&xop->dst_pt_cmd->se_cmd, 0);
}

xcopy_pt_undepend_remotedev(xop);
Expand Down
5 changes: 0 additions & 5 deletions drivers/target/target_core_xcopy.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,8 +18,6 @@ enum xcopy_origin_list {
XCOL_DEST_RECV_OP = 0x02,
};

struct xcopy_pt_cmd;

struct xcopy_op {
int op_origin;

Expand All @@ -36,9 +34,6 @@ struct xcopy_op {
unsigned short dtdi;
unsigned short nolb;

struct xcopy_pt_cmd *src_pt_cmd;
struct xcopy_pt_cmd *dst_pt_cmd;

u32 xop_data_bytes;
u32 xop_data_nents;
struct scatterlist *xop_data_sg;
Expand Down

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