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Commit a50da144 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Nicholas Bellinger
Browse files

target: support zero allocation length in SBC commands 



READ CAPACITY must be subject to the same treatment as INQUIRY,
REQUEST SENSE, and MODE SENSE, but there are no pre-existing bugs
to fix here.  Just use an on-stack buffer, and copy to it after
checking the return value of transport_kmap_data_sg.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 7a3f369c

drivers/target/target_core_sbc.c

+15 −8
Original line number Original line Diff line number Diff line
@@ -40,8 +40,9 @@ 
static int sbc_emulate_readcapacity(struct se_cmd *cmd)

static int sbc_emulate_readcapacity(struct se_cmd *cmd)

{

{

	struct se_device *dev = cmd->se_dev;

	struct se_device *dev = cmd->se_dev;

	unsigned char *buf;

	unsigned long long blocks_long = dev->transport->get_blocks(dev);

	unsigned long long blocks_long = dev->transport->get_blocks(dev);

	unsigned char *rbuf;

	unsigned char buf[8];

	u32 blocks;

	u32 blocks;





	if (blocks_long >= 0x00000000ffffffff)

	if (blocks_long >= 0x00000000ffffffff)
@@ -49,8 +50,6 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) 
	else

	else

		blocks = (u32)blocks_long;

		blocks = (u32)blocks_long;





	buf = transport_kmap_data_sg(cmd);



	buf[0] = (blocks >> 24) & 0xff;

	buf[0] = (blocks >> 24) & 0xff;

	buf[1] = (blocks >> 16) & 0xff;

	buf[1] = (blocks >> 16) & 0xff;

	buf[2] = (blocks >> 8) & 0xff;

	buf[2] = (blocks >> 8) & 0xff;
@@ -60,7 +59,11 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) 
	buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;

	buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;

	buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;

	buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;





	rbuf = transport_kmap_data_sg(cmd);

	if (rbuf) {

		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));

		transport_kunmap_data_sg(cmd);

		transport_kunmap_data_sg(cmd);

	}





	target_complete_cmd(cmd, GOOD);

	target_complete_cmd(cmd, GOOD);

	return 0;

	return 0;
@@ -69,11 +72,11 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd) 
static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)

static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)

{

{

	struct se_device *dev = cmd->se_dev;

	struct se_device *dev = cmd->se_dev;

	unsigned char *buf;

	unsigned char *rbuf;

	unsigned char buf[32];

	unsigned long long blocks = dev->transport->get_blocks(dev);

	unsigned long long blocks = dev->transport->get_blocks(dev);





	buf = transport_kmap_data_sg(cmd);

	memset(buf, 0, sizeof(buf));



	buf[0] = (blocks >> 56) & 0xff;

	buf[0] = (blocks >> 56) & 0xff;

	buf[1] = (blocks >> 48) & 0xff;

	buf[1] = (blocks >> 48) & 0xff;

	buf[2] = (blocks >> 40) & 0xff;

	buf[2] = (blocks >> 40) & 0xff;
@@ -93,7 +96,11 @@ static int sbc_emulate_readcapacity_16(struct se_cmd *cmd) 
	if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)

	if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)

		buf[14] = 0x80;

		buf[14] = 0x80;





	rbuf = transport_kmap_data_sg(cmd);

	if (rbuf) {

		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));

		transport_kunmap_data_sg(cmd);

		transport_kunmap_data_sg(cmd);

	}





	target_complete_cmd(cmd, GOOD);

	target_complete_cmd(cmd, GOOD);

	return 0;

	return 0;