From 2426bd456a61407388b6e61fc5f98dbcbebc50e2 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 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 Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger --- 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 97a33603795d..1d3a626bf24f 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; } @@ -137,7 +137,7 @@ 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 17b5b7e099fa..6cd7222738fc 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -716,6 +716,7 @@ 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) { @@ -737,6 +738,7 @@ spc_emulate_inquiry(struct se_cmd *cmd) } ret = spc_emulate_inquiry_std(cmd, buf); + len = buf[4] + 5; goto out; } @@ -744,6 +746,7 @@ 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; } } @@ -760,7 +763,7 @@ out: kfree(buf); if (!ret) - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, len); return ret; } @@ -1098,7 +1101,7 @@ set_length: transport_kunmap_data_sg(cmd); } - target_complete_cmd(cmd, GOOD); + target_complete_cmd_with_length(cmd, GOOD, length); return 0; } @@ -1274,7 +1277,7 @@ 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 15dbf6e97289..c9e8b35a954f 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -703,6 +703,23 @@ 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 3a1c1eea1fff..9adc1bca1178 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); -- 2.20.1