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authorPaolo Bonzini <pbonzini@redhat.com>2012-09-07 17:30:38 +0200
committerNicholas Bellinger <nab@linux-iscsi.org>2012-09-17 17:13:36 -0700
commitffe7b0e9326d9c68f5688bef691dd49f1e0d3651 (patch)
treef180001bbe2685c8388c372766e6884f2cb7845e /drivers/target
parentbf11eefcb1dc1326341ebdc44566ad08bee3f539 (diff)
downloadop-kernel-dev-ffe7b0e9326d9c68f5688bef691dd49f1e0d3651.zip
op-kernel-dev-ffe7b0e9326d9c68f5688bef691dd49f1e0d3651.tar.gz
target: support zero allocation length in INQUIRY
INQUIRY processing already uses an on-heap bounce buffer for loopback, but not for other fabrics. Switch this to a cheaper on-stack bounce buffer, similar to the one used by MODE SENSE and REQUEST SENSE, and use it unconditionally. With this in place, zero allocation length is handled simply by checking the return address of transport_kmap_data_sg. Testcase: sg_raw /dev/sdb 12 00 83 00 00 00 should fail with ILLEGAL REQUEST / INVALID FIELD IN CDB sense does not fail without the patch fails correctly with the series Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_spc.c31
1 files changed, 6 insertions, 25 deletions
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 388a922..b3d8fd2 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -600,30 +600,11 @@ static int spc_emulate_inquiry(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_portal_group *tpg = cmd->se_lun->lun_sep->sep_tpg;
- unsigned char *buf, *map_buf;
+ unsigned char *rbuf;
unsigned char *cdb = cmd->t_task_cdb;
+ unsigned char buf[SE_INQUIRY_BUF];
int p, ret;
- map_buf = transport_kmap_data_sg(cmd);
- /*
- * If SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC is not set, then we
- * know we actually allocated a full page. Otherwise, if the
- * data buffer is too small, allocate a temporary buffer so we
- * don't have to worry about overruns in all our INQUIRY
- * emulation handling.
- */
- if (cmd->data_length < SE_INQUIRY_BUF &&
- (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)) {
- buf = kzalloc(SE_INQUIRY_BUF, GFP_KERNEL);
- if (!buf) {
- transport_kunmap_data_sg(cmd);
- cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- return -ENOMEM;
- }
- } else {
- buf = map_buf;
- }
-
if (dev == tpg->tpg_virt_lun0.lun_se_dev)
buf[0] = 0x3f; /* Not connected */
else
@@ -655,11 +636,11 @@ static int spc_emulate_inquiry(struct se_cmd *cmd)
ret = -EINVAL;
out:
- if (buf != map_buf) {
- memcpy(map_buf, buf, cmd->data_length);
- kfree(buf);
+ 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);
if (!ret)
target_complete_cmd(cmd, GOOD);
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