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authorPaolo Bonzini <pbonzini@redhat.com>2012-09-07 17:30:40 +0200
committerNicholas Bellinger <nab@linux-iscsi.org>2012-09-17 17:13:38 -0700
commita50da144d048f9dbebed2b1441ed779d6bbbcd03 (patch)
tree25290267964578f79c10590a6511d10b85e7de96 /drivers/target/target_core_sbc.c
parent7a3f369ce31694017996524a1cdb08208a839077 (diff)
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: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_sbc.c')
-rw-r--r--drivers/target/target_core_sbc.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index a9dd9469e3b..868f8aa04f1 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -40,8 +40,9 @@
static int sbc_emulate_readcapacity(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
- unsigned char *buf;
unsigned long long blocks_long = dev->transport->get_blocks(dev);
+ unsigned char *rbuf;
+ unsigned char buf[8];
u32 blocks;
if (blocks_long >= 0x00000000ffffffff)
@@ -49,8 +50,6 @@ static int sbc_emulate_readcapacity(struct se_cmd *cmd)
else
blocks = (u32)blocks_long;
- buf = transport_kmap_data_sg(cmd);
-
buf[0] = (blocks >> 24) & 0xff;
buf[1] = (blocks >> 16) & 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[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
- transport_kunmap_data_sg(cmd);
+ rbuf = transport_kmap_data_sg(cmd);
+ if (rbuf) {
+ memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
+ transport_kunmap_data_sg(cmd);
+ }
target_complete_cmd(cmd, GOOD);
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)
{
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);
- buf = transport_kmap_data_sg(cmd);
-
+ memset(buf, 0, sizeof(buf));
buf[0] = (blocks >> 56) & 0xff;
buf[1] = (blocks >> 48) & 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)
buf[14] = 0x80;
- transport_kunmap_data_sg(cmd);
+ rbuf = transport_kmap_data_sg(cmd);
+ if (rbuf) {
+ memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
+ transport_kunmap_data_sg(cmd);
+ }
target_complete_cmd(cmd, GOOD);
return 0;