From 61f36166c245e563c7a2b624f4c78c5ce0f680d6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 16 Oct 2016 00:27:42 -0700 Subject: [PATCH] Revert "target: Fix residual overflow handling in target_complete_cmd_with_length" This reverts commit c1ccbfe0311e2380a6d2dcb0714b36904f5d586f. Reverting this patch, as it incorrectly assumes the additional length for INQUIRY in target_complete_cmd_with_length() is SCSI allocation length, which breaks existing user-space code when SCSI allocation length is smaller than additional length. root@scsi-mq:~# sg_inq --len=4 -vvvv /dev/sdb found bsg_major=253 open /dev/sdb with flags=0x800 inquiry cdb: 12 00 00 00 04 00 duration=0 ms inquiry: pass-through requested 4 bytes (data-in) but got -28 bytes inquiry: pass-through can't get negative bytes, say it got none inquiry: got too few bytes (0) INQUIRY resid (32) should never exceed requested len=4 inquiry: failed requesting 4 byte response: Malformed response to SCSI command [resid=32] AFAICT the original change was not to address a specific host issue, so go ahead and revert to original logic for now. Cc: Douglas Gilbert Cc: Martin K. Petersen Cc: Sumit Rai Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 000bc6d077ea..e825d580ccee 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -754,15 +754,7 @@ 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) { - return; - } - - /* - * Calculate new residual count based upon length of SCSI data - * transferred. - */ - if (length < cmd->data_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 { @@ -771,12 +763,6 @@ void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int len } cmd->data_length = length; - } else if (length > cmd->data_length) { - cmd->se_cmd_flags |= SCF_OVERFLOW_BIT; - cmd->residual_count = length - cmd->data_length; - } else { - cmd->se_cmd_flags &= ~(SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT); - cmd->residual_count = 0; } target_complete_cmd(cmd, scsi_status);