4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Bryant G. Ly <[email protected]> commit 75dbf2d36f6b122ad3c1070fe4bf95f71bbff321 upstream. The current code is not correctly calculating the req_lim_delta. We want to make sure vscsi->credit is always incremented when we do not send a response for the scsi op. Thus for the case where there is a successfully aborted task we need to make sure the vscsi->credit is incremented. v2 - Moves the original location of the vscsi->credit increment to a better spot. Since if we increment credit, the next command we send back will have increased req_lim_delta. But we probably shouldn't be doing that until the aborted cmd is actually released. Otherwise the client will think that it can send a new command, and we could find ourselves short of command elements. Not likely, but could happen. This patch depends on both: commit 25e78531268e ("ibmvscsis: Do not send aborted task response") commit 98883f1b5415 ("ibmvscsis: Clear left-over abort_cmd pointers") Signed-off-by: Bryant G. Ly <[email protected]> Reviewed-by: Michael Cyr <[email protected]> Signed-off-by: Nicholas Bellinger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) --- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c +++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c @@ -1790,6 +1790,25 @@ static void ibmvscsis_send_messages(stru list_del(&cmd->list); ibmvscsis_free_cmd_resources(vscsi, cmd); + /* + * With a successfully aborted op + * through LIO we want to increment the + * the vscsi credit so that when we dont + * send a rsp to the original scsi abort + * op (h_send_crq), but the tm rsp to + * the abort is sent, the credit is + * correctly sent with the abort tm rsp. + * We would need 1 for the abort tm rsp + * and 1 credit for the aborted scsi op. + * Thus we need to increment here. + * Also we want to increment the credit + * here because we want to make sure + * cmd is actually released first + * otherwise the client will think it + * it can send a new cmd, and we could + * find ourselves short of cmd elements. + */ + vscsi->credit += 1; } else { iue = cmd->iue; @@ -2964,10 +2983,7 @@ static long srp_build_response(struct sc rsp->opcode = SRP_RSP; - if (vscsi->credit > 0 && vscsi->state == SRP_PROCESSING) - rsp->req_lim_delta = cpu_to_be32(vscsi->credit); - else - rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); + rsp->req_lim_delta = cpu_to_be32(1 + vscsi->credit); rsp->tag = cmd->rsp.tag; rsp->flags = 0;
