From 32a8811ff164f882712c17946e58e52444f464a7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 7 Sep 2012 17:30:36 +0200 Subject: 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 Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_spc.c | 35 ++++++++++++++++++----------------- include/target/target_core_base.h | 1 + 2 files changed, 19 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; } diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index 015cea01ae39..5be89373ceac 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -121,6 +121,7 @@ #define SE_INQUIRY_BUF 512 #define SE_MODE_PAGE_BUF 512 +#define SE_SENSE_BUF 96 /* struct se_hba->hba_flags */ enum hba_flags_table { -- cgit v1.2.2