4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit 61f36166c245e563c7a2b624f4c78c5ce0f680d6 upstream.
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 <dgilbert@xxxxxxxxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Sumit Rai <sumitrai96@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
--- 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(str
}
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);
--
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