From 9a7f545e75cef29dbdc4c585f3ae27c5f7f4ea48 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Tue, 10 Jun 2014 11:07:47 -0700 Subject: [PATCH] target: Report correct response length for some commands commit 2426bd456a61407388b6e61fc5f98dbcbebc50e2 upstream. When an initiator sends an allocation length bigger than what its command consumes, the target should only return the actual response data and set the residual length to the unused part of the allocation length. Add a helper function that command handlers (INQUIRY, READ CAPACITY, etc) can use to do this correctly, and use this code to get the correct residual for commands that don't use the full initiator allocation in the handlers for READ CAPACITY, READ CAPACITY(16), INQUIRY, MODE SENSE and REPORT LUNS. This addresses a handful of failures as reported by Christophe with the Windows Certification Kit: http://permalink.gmane.org/gmane.linux.scsi.target.devel/6515 Signed-off-by: Roland Dreier Tested-by: Christophe Vu-Brugier Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_sbc.c | 4 ++-- drivers/target/target_core_spc.c | 9 ++++++--- drivers/target/target_core_transport.c | 17 +++++++++++++++++ include/target/target_core_backend.h | 1 + 4 files changed, 26 insertions(+), 5 deletions(-) diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c index aa064a7bb446..379033f5903b 100644 --- a/drivers/target/target_core_sbc.c +++ b/drivers/target/target_core_sbc.c @@ -81,7 +81,7 @@ sbc_emulate_readcapacity(struct se_cmd *cmd) transport_kunmap_data_sg(cmd); } - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, 8); return 0; } @@ -134,7 +134,7 @@ sbc_emulate_readcapacity_16(struct se_cmd *cmd) transport_kunmap_data_sg(cmd); } - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, 32); return 0; } diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index 3bebc71ea033..fcdf98fc947c 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -714,6 +714,7 @@ spc_emulate_inquiry(struct se_cmd *cmd) unsigned char *buf; sense_reason_t ret; int p; + int len = 0; buf = kzalloc(SE_INQUIRY_BUF, GFP_KERNEL); if (!buf) { @@ -735,6 +736,7 @@ spc_emulate_inquiry(struct se_cmd *cmd) } ret = spc_emulate_inquiry_std(cmd, buf); + len = buf[4] + 5; goto out; } @@ -742,6 +744,7 @@ spc_emulate_inquiry(struct se_cmd *cmd) if (cdb[2] == evpd_handlers[p].page) { buf[1] = cdb[2]; ret = evpd_handlers[p].emulate(cmd, buf); + len = get_unaligned_be16(&buf[2]) + 4; goto out; } } @@ -758,7 +761,7 @@ out: kfree(buf); if (!ret) - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, len); return ret; } @@ -1089,7 +1092,7 @@ set_length: transport_kunmap_data_sg(cmd); } - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, length); return 0; } @@ -1266,7 +1269,7 @@ done: buf[3] = (lun_count & 0xff); transport_kunmap_data_sg(cmd); - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, 8 + lun_count * 8); return 0; } EXPORT_SYMBOL(spc_emulate_report_luns); diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index d3963617d8ec..24f527977ddb 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -692,6 +692,23 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status) } EXPORT_SYMBOL(target_complete_cmd); +void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length) +{ + if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) { + if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) { + cmd->residual_count += cmd->data_length - length; + } else { + cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT; + cmd->residual_count = cmd->data_length - length; + } + + cmd->data_length = length; + } + + target_complete_cmd(cmd, scsi_status); +} +EXPORT_SYMBOL(target_complete_cmd_with_length); + static void target_add_to_state_list(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index 7020e33e742e..f5915b39386a 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -59,6 +59,7 @@ int transport_subsystem_register(struct se_subsystem_api *); void transport_subsystem_release(struct se_subsystem_api *); void target_complete_cmd(struct se_cmd *, u8); +void target_complete_cmd_with_length(struct se_cmd *, u8, int); sense_reason_t spc_parse_cdb(struct se_cmd *cmd, unsigned int *size); sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd);