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xprtrdma: Fix DMAR failure in frwr_op_map() after reconnect

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When a LOCALINV WR is flushed, the frmr is marked STALE, then
frwr_op_unmap_sync DMA-unmaps the frmr's SGL. These STALE frmrs
are then recovered when frwr_op_map hunts for an INVALID frmr to
use.

All other cases that need frmr recovery leave that SGL DMA-mapped.
The FRMR recovery path unconditionally DMA-unmaps the frmr's SGL.

To avoid DMA unmapping the SGL twice for flushed LOCAL_INV WRs,
alter the recovery logic (rather than the hot frwr_op_unmap_sync
path) to distinguish among these cases. This solution also takes
care of the case where multiple LOCAL_INV WRs are issued for the
same rpcrdma_req, some complete successfully, but some are flushed.

Reported-by: Vasco Steinmetz <linux@kyberraum.net>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Vasco Steinmetz <linux@kyberraum.net>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2016-11-07 16:16:24 -05:00 committed by Anna Schumaker
parent 0ac84b72c0
commit 62bdf94a20
2 changed files with 24 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
net/sunrpc/xprtrdma/frwr_ops.c
View File

@ -44,18 +44,20 @@
* being done.
*
* When the underlying transport disconnects, MRs are left in one of
* three states:
* four states:
*
* INVALID: The MR was not in use before the QP entered ERROR state.
* (Or, the LOCAL_INV WR has not completed or flushed yet).
*
* STALE: The MR was being registered or unregistered when the QP
* entered ERROR state, and the pending WR was flushed.
*
* VALID: The MR was registered before the QP entered ERROR state.
*
* When frwr_op_map encounters STALE and VALID MRs, they are recovered
* with ib_dereg_mr and then are re-initialized. Beause MR recovery
* FLUSHED_FR: The MR was being registered when the QP entered ERROR
* state, and the pending WR was flushed.
*
* FLUSHED_LI: The MR was being invalidated when the QP entered ERROR
* state, and the pending WR was flushed.
*
* When frwr_op_map encounters FLUSHED and VALID MRs, they are recovered
* with ib_dereg_mr and then are re-initialized. Because MR recovery
* allocates fresh resources, it is deferred to a workqueue, and the
* recovered MRs are placed back on the rb_mws list when recovery is
* complete. frwr_op_map allocates another MR for the current RPC while
@ -177,12 +179,15 @@ __frwr_reset_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r)
static void
frwr_op_recover_mr(struct rpcrdma_mw *mw)
{
enum rpcrdma_frmr_state state = mw->frmr.fr_state;
struct rpcrdma_xprt *r_xprt = mw->mw_xprt;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
int rc;
rc = __frwr_reset_mr(ia, mw);
ib_dma_unmap_sg(ia->ri_device, mw->mw_sg, mw->mw_nents, mw->mw_dir);
if (state != FRMR_FLUSHED_LI)
ib_dma_unmap_sg(ia->ri_device,
mw->mw_sg, mw->mw_nents, mw->mw_dir);
if (rc)
goto out_release;
@ -262,10 +267,8 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
}
static void
__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_frmr *frmr,
const char *wr)
__frwr_sendcompletion_flush(struct ib_wc *wc, const char *wr)
{
frmr->fr_state = FRMR_IS_STALE;
if (wc->status != IB_WC_WR_FLUSH_ERR)
pr_err("rpcrdma: %s: %s (%u/0x%x)\n",
wr, ib_wc_status_msg(wc->status),
@ -288,7 +291,8 @@ frwr_wc_fastreg(struct ib_cq *cq, struct ib_wc *wc)
if (wc->status != IB_WC_SUCCESS) {
cqe = wc->wr_cqe;
frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
__frwr_sendcompletion_flush(wc, frmr, "fastreg");
frmr->fr_state = FRMR_FLUSHED_FR;
__frwr_sendcompletion_flush(wc, "fastreg");
}
}
@ -308,7 +312,8 @@ frwr_wc_localinv(struct ib_cq *cq, struct ib_wc *wc)
if (wc->status != IB_WC_SUCCESS) {
cqe = wc->wr_cqe;
frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
__frwr_sendcompletion_flush(wc, frmr, "localinv");
frmr->fr_state = FRMR_FLUSHED_LI;
__frwr_sendcompletion_flush(wc, "localinv");
}
}
@ -328,8 +333,10 @@ frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc)
/* WARNING: Only wr_cqe and status are reliable at this point */
cqe = wc->wr_cqe;
frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);
if (wc->status != IB_WC_SUCCESS)
__frwr_sendcompletion_flush(wc, frmr, "localinv");
if (wc->status != IB_WC_SUCCESS) {
frmr->fr_state = FRMR_FLUSHED_LI;
__frwr_sendcompletion_flush(wc, "localinv");
}
complete(&frmr->fr_linv_done);
}

3
net/sunrpc/xprtrdma/xprt_rdma.h
View File

@ -216,7 +216,8 @@ struct rpcrdma_rep {
enum rpcrdma_frmr_state {
FRMR_IS_INVALID, /* ready to be used */
FRMR_IS_VALID, /* in use */
FRMR_IS_STALE, /* failed completion */
FRMR_FLUSHED_FR, /* flushed FASTREG WR */
FRMR_FLUSHED_LI, /* flushed LOCALINV WR */
};
struct rpcrdma_frmr {