diff mbox series

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

Message ID 20220630122241.1658-4-a.kovaleva@yadro.com (mailing list archive)
State Changes Requested
Headers show
Series Make target send correct io limits | expand

Commit Message

Anastasia Kovaleva June 30, 2022, 12:22 p.m. UTC 
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 thransmition 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 | 68 ++++++++++++++++--------------
 drivers/target/target_core_xcopy.h |  2 +-
 2 files changed, 37 insertions(+), 33 deletions(-)

Comments

kernel test robot July 1, 2022, 3:43 a.m. UTC | #1 
Hi Anastasia,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on mkp-scsi/for-next]
[also build test WARNING on linus/master v5.19-rc4 next-20220630]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
config: i386-randconfig-a002
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a9119143a2d1f4d0d0bc1fe0d819e5351b4e0deb)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/56a549ae44a7fa719292ad848e1f70fa745d0ece
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
        git checkout 56a549ae44a7fa719292ad848e1f70fa745d0ece
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/target/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/target/target_core_xcopy.c:765:3: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat]
                   copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/printk.h:599:26: note: expanded from macro 'pr_debug'
           dynamic_pr_debug(fmt, ##__VA_ARGS__)
                            ~~~    ^~~~~~~~~~~
   include/linux/dynamic_debug.h:163:22: note: expanded from macro 'dynamic_pr_debug'
                              pr_fmt(fmt), ##__VA_ARGS__)
                                     ~~~     ^~~~~~~~~~~
   include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call'
           __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
                                                                 ^~~~~~~~~~~
   include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call'
                   func(&id, ##__VA_ARGS__);               \
                               ^~~~~~~~~~~
   1 warning generated.


vim +765 drivers/target/target_core_xcopy.c

   666	
   667	static void target_xcopy_do_work(struct work_struct *work)
   668	{
   669		struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
   670		struct se_cmd *ec_cmd = xop->xop_se_cmd;
   671		struct se_device *src_dev, *dst_dev;
   672		sector_t src_lba, dst_lba, end_lba;
   673		unsigned long long int max_bytes, max_bytes_src, max_bytes_dst, max_blocks;
   674		int rc = 0;
   675		unsigned short nolb;
   676		unsigned int copied_bytes = 0;
   677		sense_reason_t sense_rc;
   678	
   679		sense_rc = target_parse_xcopy_cmd(xop);
   680		if (sense_rc != TCM_NO_SENSE)
   681			goto err_free;
   682	
   683		if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
   684			sense_rc = TCM_INVALID_PARAMETER_LIST;
   685			goto err_free;
   686		}
   687	
   688		src_dev = xop->src_dev;
   689		dst_dev = xop->dst_dev;
   690		src_lba = xop->src_lba;
   691		dst_lba = xop->dst_lba;
   692		nolb = xop->nolb;
   693		end_lba = src_lba + nolb;
   694		/*
   695		 * Break up XCOPY I/O into hw_max_sectors * hw_block_size sized
   696		 * I/O based on the smallest max_bytes between src_dev + dst_dev
   697		 */
   698		max_bytes_src = (unsigned long long) src_dev->dev_attrib.hw_max_sectors *
   699				src_dev->dev_attrib.hw_block_size;
   700		max_bytes_dst = (unsigned long long) dst_dev->dev_attrib.hw_max_sectors *
   701				dst_dev->dev_attrib.hw_block_size;
   702	
   703		max_bytes = min_t(u64, max_bytes_src, max_bytes_dst);
   704		max_bytes = min_t(u64, max_bytes, XCOPY_MAX_BYTES);
   705		max_blocks = max_bytes / src_dev->dev_attrib.block_size;
   706	
   707		pr_debug("target_xcopy_do_work: nolb: %hu, max_blocks: %llu end_lba: %llu\n",
   708				nolb, max_blocks, (unsigned long long)end_lba);
   709		pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
   710				(unsigned long long)src_lba, (unsigned long long)dst_lba);
   711	
   712		while (nolb) {
   713			u32 cur_bytes = min_t(u64, max_bytes, nolb * src_dev->dev_attrib.block_size);
   714			unsigned short cur_nolb = cur_bytes / src_dev->dev_attrib.block_size;
   715	
   716			if (cur_bytes != xop->xop_data_bytes) {
   717				/*
   718				 * (Re)allocate a buffer large enough to hold the XCOPY
   719				 * I/O size, which can be reused each read / write loop.
   720				 */
   721				target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
   722				rc = target_alloc_sgl(&xop->xop_data_sg,
   723						      &xop->xop_data_nents,
   724						      cur_bytes,
   725						      false, false);
   726				if (rc < 0)
   727					goto out;
   728				xop->xop_data_bytes = cur_bytes;
   729			}
   730	
   731			pr_debug("target_xcopy_do_work: Calling read src_dev: %p src_lba: %llu,"
   732				" cur_nolb: %hu\n", src_dev, (unsigned long long)src_lba, cur_nolb);
   733	
   734			rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_bytes);
   735			if (rc < 0)
   736				goto out;
   737	
   738			src_lba += cur_bytes / src_dev->dev_attrib.block_size;
   739			pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
   740					(unsigned long long)src_lba);
   741	
   742			pr_debug("target_xcopy_do_work: Calling write dst_dev: %p dst_lba: %llu,"
   743				" cur_nolb: %hu\n", dst_dev, (unsigned long long)dst_lba, cur_nolb);
   744	
   745			rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
   746							dst_lba, cur_bytes);
   747			if (rc < 0)
   748				goto out;
   749	
   750			dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
   751			pr_debug("target_xcopy_do_work: Incremented WRITE dst_lba to %llu\n",
   752					(unsigned long long)dst_lba);
   753	
   754			copied_bytes += cur_bytes;
   755			nolb -= cur_bytes / src_dev->dev_attrib.block_size;
   756		}
   757	
   758		xcopy_pt_undepend_remotedev(xop);
   759		target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
   760		kfree(xop);
   761	
   762		pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
   763			(unsigned long long)src_lba, (unsigned long long)dst_lba);
   764		pr_debug("target_xcopy_do_work: Blocks copied: %hu, Bytes Copied: %u\n",
 > 765			copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
   766	
   767		pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
   768		target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
   769		return;
   770	
   771	out:
   772		/*
   773		 * The XCOPY command was aborted after some data was transferred.
   774		 * Terminate command with CHECK CONDITION status, with the sense key
   775		 * set to COPY ABORTED.
   776		 */
   777		sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
   778		xcopy_pt_undepend_remotedev(xop);
   779		target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
   780	
   781	err_free:
   782		kfree(xop);
   783		pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
   784				   rc, sense_rc);
   785		target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
   786	}
   787
kernel test robot July 1, 2022, 4:35 a.m. UTC | #2 
Hi Anastasia,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on mkp-scsi/for-next]
[also build test ERROR on linus/master v5.19-rc4 next-20220630]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
config: i386-randconfig-a005 (https://download.01.org/0day-ci/archive/20220701/202207011237.RwOL3m3V-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/56a549ae44a7fa719292ad848e1f70fa745d0ece
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
        git checkout 56a549ae44a7fa719292ad848e1f70fa745d0ece
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: drivers/target/target_core_xcopy.o: in function `target_xcopy_do_work':
>> target_core_xcopy.c:(.text+0x138d): undefined reference to `__udivdi3'
kernel test robot July 2, 2022, 11:47 a.m. UTC | #3 
Hi Anastasia,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on mkp-scsi/for-next]
[also build test ERROR on linus/master v5.19-rc4 next-20220701]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20220702/202207021939.V7V97GD3-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 11.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/56a549ae44a7fa719292ad848e1f70fa745d0ece
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Anastasia-Kovaleva/Make-target-send-correct-io-limits/20220630-203342
        git checkout 56a549ae44a7fa719292ad848e1f70fa745d0ece
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__divdi3" [drivers/target/target_core_mod.ko] undefined!
>> ERROR: modpost: "__udivdi3" [drivers/target/target_core_mod.ko] undefined!
Mike Christie July 7, 2022, 10:37 p.m. UTC | #4 
On 6/30/22 7:22 AM, Anastasia Kovaleva wrote:
> 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 thransmition size into bytes.

I think it's "transmission".

Run the scripts/checkpatch.pl on the patch and fix up those warnings.

Also don't forget to checkout the kernel test bot warnings.

> 
> 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 | 68 ++++++++++++++++--------------
>  drivers/target/target_core_xcopy.h |  2 +-
>  2 files changed, 37 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
> index 6bb20aa9c5bc..c9341a92b567 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 = src_bytes / src_dev->dev_attrib.block_size;
 
It was nice how in the patches you added a bytes/blocks to the variable
names. Maybe do that here and the other transfer_length you added? I
wasn't sure if you just forgot or maybe adding a "block" in the name made
it sound weird.
diff mbox series

Patch

diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 6bb20aa9c5bc..c9341a92b567 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 = 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, &cdb[10]);
+	pr_debug("XCOPY: Built READ_16: LBA: %llu Blocks: %u Length: %u\n",
+		(unsigned long long)src_lba, transfer_length, 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 = 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, &cdb[10]);
+	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Blocks: %u Length: %u\n",
+		(unsigned long long)dst_lba, transfer_length, 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 int 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_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_nolb = min_t(u16, max_sectors, ((u16)(~0U)));
+	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("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: nolb: %hu, max_blocks: %llu end_lba: %llu\n",
+			nolb, max_blocks, (unsigned long long)end_lba);
 	pr_debug("target_xcopy_do_work: Starting src_lba: %llu, dst_lba: %llu\n",
 			(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) {
 			/*
@@ -727,11 +731,11 @@  static void target_xcopy_do_work(struct work_struct *work)
 		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);
 
-		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;
+		src_lba += cur_bytes / src_dev->dev_attrib.block_size;
 		pr_debug("target_xcopy_do_work: Incremented READ src_lba to %llu\n",
 				(unsigned long long)src_lba);
 
@@ -739,16 +743,16 @@  static void target_xcopy_do_work(struct work_struct *work)
 			" cur_nolb: %hu\n", 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;
+		dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
 		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;
+		copied_bytes += cur_bytes;
+		nolb -= cur_bytes / src_dev->dev_attrib.block_size;
 	}
 
 	xcopy_pt_undepend_remotedev(xop);
@@ -758,7 +762,7 @@  static void target_xcopy_do_work(struct work_struct *work)
 	pr_debug("target_xcopy_do_work: Final src_lba: %llu, dst_lba: %llu\n",
 		(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);
+		copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
 
 	pr_debug("target_xcopy_do_work: Setting X-COPY GOOD status -> sending response\n");
 	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
diff --git a/drivers/target/target_core_xcopy.h b/drivers/target/target_core_xcopy.h
index e5f20005179a..51a8e4d85d3e 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