From a762dce41cb5742a143f6aa2d80ee1aac7e1f5eb Mon Sep 17 00:00:00 2001 From: Yi Zou Date: Fri, 13 Jan 2012 17:26:15 -0800 Subject: [SCSI] fcoe: fix regression on offload em matching function for initiator/target 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 Tested-by: Ross Brattain Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/fcoe/fcoe.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'drivers/scsi/fcoe/fcoe.c') diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index e535f95e477..507504b7788 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; -- cgit v1.2.3