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authorPaolo Bonzini <pbonzini@redhat.com>2012-09-07 17:30:36 +0200
committerNicholas Bellinger <nab@linux-iscsi.org>2012-09-07 11:14:21 -0700
commit32a8811ff164f882712c17946e58e52444f464a7 (patch)
treef7af9ff41cd4f4e6c61a831c4e14fb1d57ebe05d /drivers/target
parent3717ef0c63e90686d959158e9728a13a49229be6 (diff)
target: support zero allocation length in REQUEST SENSE
Similar to INQUIRY and MODE SENSE, construct the sense data in a buffer and later copy it to the scatterlist. Do not do anything, but still clear a pending unit attention condition, if the allocation length is zero. However, SPC tells us that "If a REQUEST SENSE command is terminated with CHECK CONDITION status [and] the REQUEST SENSE command was received on an I_T nexus with a pending unit attention condition (i.e., before the device server reports CHECK CONDITION status), then the device server shall not clear the pending unit attention condition." Do the transport_kmap_data_sg early to detect this case. It also tells us "Device servers shall not adjust the additional sense length to reflect truncation if the allocation length is less than the sense data available", so do not do that! Note that the err variable is write-only. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_spc.c35
1 files changed, 18 insertions, 17 deletions
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 4c861de538c9..388a922c8f6d 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -877,9 +877,11 @@ static int spc_emulate_modesense(struct se_cmd *cmd)
static int spc_emulate_request_sense(struct se_cmd *cmd)
{
unsigned char *cdb = cmd->t_task_cdb;
- unsigned char *buf;
+ unsigned char *rbuf;
u8 ua_asc = 0, ua_ascq = 0;
- int err = 0;
+ unsigned char buf[SE_SENSE_BUF];
+
+ memset(buf, 0, SE_SENSE_BUF);
if (cdb[1] & 0x01) {
pr_err("REQUEST_SENSE description emulation not"
@@ -888,20 +890,21 @@ static int spc_emulate_request_sense(struct se_cmd *cmd)
return -ENOSYS;
}
- buf = transport_kmap_data_sg(cmd);
-
- if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq)) {
+ rbuf = transport_kmap_data_sg(cmd);
+ if (cmd->scsi_sense_reason != 0) {
+ /*
+ * Out of memory. We will fail with CHECK CONDITION, so
+ * we must not clear the unit attention condition.
+ */
+ target_complete_cmd(cmd, CHECK_CONDITION);
+ return 0;
+ } else if (!core_scsi3_ua_clear_for_request_sense(cmd, &ua_asc, &ua_ascq)) {
/*
* CURRENT ERROR, UNIT ATTENTION
*/
buf[0] = 0x70;
buf[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
- if (cmd->data_length < 18) {
- buf[7] = 0x00;
- err = -EINVAL;
- goto end;
- }
/*
* The Additional Sense Code (ASC) from the UNIT ATTENTION
*/
@@ -915,11 +918,6 @@ static int spc_emulate_request_sense(struct se_cmd *cmd)
buf[0] = 0x70;
buf[SPC_SENSE_KEY_OFFSET] = NO_SENSE;
- if (cmd->data_length < 18) {
- buf[7] = 0x00;
- err = -EINVAL;
- goto end;
- }
/*
* NO ADDITIONAL SENSE INFORMATION
*/
@@ -927,8 +925,11 @@ static int spc_emulate_request_sense(struct se_cmd *cmd)
buf[7] = 0x0A;
}
-end:
- transport_kunmap_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;
}