[v2,PATCH 3/3] target: core: Change the way target_xcopy_do_work sets restiction on max io

Anastasia Kovaleva
2022-10-14T11:46:22Z

To determine how many blocks sends in one command, the minimum value is
selected from the hw_max_sectors of both devices. In
target_xcopy_do_work, hw_max_sectors are used as blocks, not sectors; it
also ignores the fact that sectors can be of different sizes, for
example 512 and 4096 bytes. Because of this, a number of blocks can be
transmitted that the device will not be able to accept.

Change the selection of max transmission size into bytes.

Signed-off-by: Anastasia Kovaleva <a.kovaleva@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Dmitriy Bogdanov <d.bogdanov@yadro.com>
---
drivers/target/target_core_xcopy.c | 96 ++++++++++++++++--------------
drivers/target/target_core_xcopy.h | 2 +-
2 files changed, 51 insertions(+), 47 deletions(-)

diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 8713cda0c2fb..55ee74a15746 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -582,11 +582,11 @@ static int target_xcopy_read_source(
struct xcopy_op *xop,
struct se_device *src_dev,
sector_t src_lba,
- u32 src_sectors)
+ u32 src_bytes)
{
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);
+ u32 transfer_length_block = src_bytes / src_dev->dev_attrib.block_size;
int rc;
unsigned char cdb[16];
bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
@@ -597,11 +597,11 @@ static int target_xcopy_read_source(
memset(&cdb[0], 0, 16);
cdb[0] = READ_16;
put_unaligned_be64(src_lba, &cdb[2]);
- put_unaligned_be32(src_sectors, &cdb[10]);
- pr_debug("XCOPY: Built READ_16: LBA: %llu Sectors: %u Length: %u\n",
- (unsigned long long)src_lba, src_sectors, length);
+ put_unaligned_be32(transfer_length_block, &cdb[10]);
+ pr_debug("XCOPY: Built READ_16: LBA: %llu Blocks: %u Length: %u\n",
+ (unsigned long long)src_lba, transfer_length_block, src_bytes);

- __target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
+ __target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, src_bytes,
DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);

rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
@@ -627,11 +627,11 @@ static int target_xcopy_write_destination(
struct xcopy_op *xop,
struct se_device *dst_dev,
sector_t dst_lba,
- u32 dst_sectors)
+ u32 dst_bytes)
{
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);
+ u32 transfer_length_block = dst_bytes / dst_dev->dev_attrib.block_size;
int rc;
unsigned char cdb[16];
bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
@@ -642,11 +642,11 @@ static int target_xcopy_write_destination(
memset(&cdb[0], 0, 16);
cdb[0] = WRITE_16;
put_unaligned_be64(dst_lba, &cdb[2]);
- put_unaligned_be32(dst_sectors, &cdb[10]);
- pr_debug("XCOPY: Built WRITE_16: LBA: %llu Sectors: %u Length: %u\n",
- (unsigned long long)dst_lba, dst_sectors, length);
+ put_unaligned_be32(transfer_length_block, &cdb[10]);
+ pr_debug("XCOPY: Built WRITE_16: LBA: %llu Blocks: %u Length: %u\n",
+ (unsigned long long)dst_lba, transfer_length_block, dst_bytes);

- __target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, length,
+ __target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, dst_bytes,
DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0);

rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
@@ -670,9 +670,10 @@ static void target_xcopy_do_work(struct work_struct *work)
struct se_cmd *ec_cmd = xop->xop_se_cmd;
struct se_device *src_dev, *dst_dev;
sector_t src_lba, dst_lba, end_lba;
- unsigned int max_sectors;
+ unsigned long long max_bytes, max_bytes_src, max_bytes_dst, max_blocks;
int rc = 0;
- unsigned short nolb, max_nolb, copied_nolb = 0;
+ unsigned short nolb;
+ unsigned int copied_bytes = 0;
sense_reason_t sense_rc;

sense_rc = target_parse_xcopy_cmd(xop);
@@ -691,23 +692,26 @@ static void target_xcopy_do_work(struct work_struct *work)
nolb = xop->nolb;
end_lba = src_lba + nolb;
/*
- * Break up XCOPY I/O into hw_max_sectors sized I/O based on the
- * smallest max_sectors between src_dev + dev_dev, or
+ * Break up XCOPY I/O into hw_max_sectors * hw_block_size sized
+ * I/O based on the smallest max_bytes between src_dev + dst_dev
*/
- max_sectors = min(src_dev->dev_attrib.hw_max_sectors,
- dst_dev->dev_attrib.hw_max_sectors);
- max_sectors = min_t(u32, max_sectors, XCOPY_MAX_SECTORS);
-
- max_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
-
- pr_debug("target_xcopy_do_work: nolb: %hu, max_nolb: %hu end_lba: %llu\n",
- nolb, max_nolb, (unsigned long long)end_lba);
- pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
+ max_bytes_src = (unsigned long long) src_dev->dev_attrib.hw_max_sectors *
+ src_dev->dev_attrib.hw_block_size;
+ max_bytes_dst = (unsigned long long) dst_dev->dev_attrib.hw_max_sectors *
+ dst_dev->dev_attrib.hw_block_size;
+
+ max_bytes = min_t(u64, max_bytes_src, max_bytes_dst);
+ max_bytes = min_t(u64, max_bytes, XCOPY_MAX_BYTES);
+ max_blocks = max_bytes / src_dev->dev_attrib.block_size;
+
+ pr_debug("%s: nolb: %u, max_blocks: %llu end_lba: %llu\n", __func__,
+ nolb, max_blocks, (unsigned long long)end_lba);
+ pr_debug("%s: Starting src_lba: %llu, dst_lba: %llu\n", __func__,
(unsigned long long)src_lba, (unsigned long long)dst_lba);

- while (src_lba < end_lba) {
- unsigned short cur_nolb = min(nolb, max_nolb);
- u32 cur_bytes = cur_nolb * src_dev->dev_attrib.block_size;
+ while (nolb) {
+ u32 cur_bytes = min_t(u64, max_bytes, nolb * src_dev->dev_attrib.block_size);
+ unsigned short cur_nolb = cur_bytes / src_dev->dev_attrib.block_size;

if (cur_bytes != xop->xop_data_bytes) {
/*
@@ -724,43 +728,43 @@ static void target_xcopy_do_work(struct work_struct *work)
xop->xop_data_bytes = cur_bytes;
}

- pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
- " cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
+ pr_debug("%s: Calling read src_dev: %p src_lba: %llu, cur_nolb: %hu\n",
+ __func__, src_dev, (unsigned long long)src_lba, cur_nolb);

- rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_nolb);
+ rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_bytes);
if (rc < 0)
goto out;

- src_lba += cur_nolb;
- pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
+ src_lba += cur_bytes / src_dev->dev_attrib.block_size;
+ pr_debug("%s: Incremented READ src_lba to %llu\n", __func__,
(unsigned long long)src_lba);

- pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
- " cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
+ pr_debug("%s: Calling write dst_dev: %p dst_lba: %llu, cur_nolb: %u\n",
+ __func__, dst_dev, (unsigned long long)dst_lba, cur_nolb);

rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
- dst_lba, cur_nolb);
+ dst_lba, cur_bytes);
if (rc < 0)
goto out;

- dst_lba += cur_nolb;
- pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
+ dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
+ pr_debug("%s: Incremented WRITE dst_lba to %llu\n", __func__,
(unsigned long long)dst_lba);

- copied_nolb += cur_nolb;
- nolb -= cur_nolb;
+ copied_bytes += cur_bytes;
+ nolb -= cur_bytes / src_dev->dev_attrib.block_size;
}

xcopy_pt_undepend_remotedev(xop);
target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
kfree(xop);

- pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
+ pr_debug("%s: Final src_lba: %llu, dst_lba: %llu\n", __func__,
(unsigned long long)src_lba, (unsigned long long)dst_lba);
- pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
- copied_nolb, copied_nolb * dst_dev->dev_attrib.block_size);
+ pr_debug("%s: Blocks copied: %u, Bytes Copied: %u\n", __func__,
+ copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);

- pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
+ pr_debug("%s: Setting X-COPY GOOD status -> sending response\n", __func__);
target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
return;

@@ -776,8 +780,8 @@ static void target_xcopy_do_work(struct work_struct *work)

err_free:
kfree(xop);
- pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
- rc, sense_rc);
+ pr_warn_ratelimited("%s: rc: %d, sense: %u, XCOPY operation failed\n",
+ __func__, rc, sense_rc);
target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
}

diff --git a/drivers/target/target_core_xcopy.h b/drivers/target/target_core_xcopy.h
index e5f20005179a..0aad7dc65895 100644
--- a/drivers/target/target_core_xcopy.h
+++ b/drivers/target/target_core_xcopy.h
@@ -5,7 +5,7 @@
#define XCOPY_TARGET_DESC_LEN 32
#define XCOPY_SEGMENT_DESC_LEN 28
#define XCOPY_NAA_IEEE_REGEX_LEN 16
-#define XCOPY_MAX_SECTORS 4096
+#define XCOPY_MAX_BYTES 16777216 /* 16 MB */

/*
* SPC4r37 6.4.6.1
--
2.30.2