From: Yi Zou <yi.zou@xxxxxxxxx>
This is a regression introduced by commit 1ff9918b625457ce20d450d00f9ed0a12ba191b7
The else statement here is breaking the initiator logic of allocating xid from the
offloaded em xid pool for READ I/O only to use DDP, as shown by the snippet of
trace below, where the WRITE is using xid 0x5 from the offloaded em xid pool:
Protocol VID Len S_ID D_ID OX_ID RX_ID Summary
..
*FCP 228 96 0b.08.01 -> 01.0f.00 0x0005 0xffff SCSI: Write(10) LUN: 0x00
FCP 228 76 01.0f.00 -> 0b.08.01 0x0005 0x828d XFER_RDY
...
The bug is in the else statement, for both initiator and target, the
new command will have FC frame header bit 23 (FC_FC_EX_CTX) cleared as it was
originated from the initiator. Also, this is assuming the frame header is
already filled up, which is only true for target since for initiator, this is a
new frame and oem_match gets called when em tries get xid for this i/o before
it is filled up and sent out.
The fix is to check if there is a fc_fcp_pkt associated w/ this frame from
fr_fsp(fp), since fr_fsp(fp) is NULL for tcm_fc target and non-I/O frame in
initiator. This should also return true for target only if it is an
FC_RCTL_DD_UNSOL_CMD and rx_id is not allocated.
Signed-off-by: Yi Zou <yi.zou@xxxxxxxxx>
Tested-by: Ross Brattain <ross.b.brattain@xxxxxxxxx>
Signed-off-by: Robert Love <robert.w.love@xxxxxxxxx>
---
drivers/scsi/fcoe/fcoe.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index e535f95..507504b 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -756,11 +756,12 @@ bool fcoe_oem_match(struct fc_frame *fp)
if (fc_fcp_is_read(fr_fsp(fp)) &&
(fr_fsp(fp)->data_len > fcoe_ddp_min))
return true;
- else if (!(ntoh24(fh->fh_f_ctl) & FC_FC_EX_CTX)) {
+ else if ((fr_fsp(fp) == NULL) &&
+ (fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD) &&
+ (ntohs(fh->fh_rx_id) == FC_XID_UNKNOWN)) {
fcp = fc_frame_payload_get(fp, sizeof(*fcp));
- if (ntohs(fh->fh_rx_id) == FC_XID_UNKNOWN &&
- fcp && (ntohl(fcp->fc_dl) > fcoe_ddp_min) &&
- (fcp->fc_flags & FCP_CFL_WRDATA))
+ if ((fcp->fc_flags & FCP_CFL_WRDATA) &&
+ (ntohl(fcp->fc_dl) > fcoe_ddp_min))
return true;
}
return false;
--
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