[PATCH net v2] rds: ib: Increment i_fastreg_wrs before bailing out

We need to increment i_fastreg_wrs before we bail out from
rds_ib_post_reg_frmr().

Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode")
Fixes: 3a2886cca703 ("net/rds: Keep track of and wait for FRWR segments in use upon shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Håkon Bugge <redacted>

---

	v1 -> v2: Added Cc: stable@vger.kernel.org
---
 net/rds/ib_frmr.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c
index 28c1b00221780..7e3b04a83904d 100644
--- a/net/rds/ib_frmr.c
+++ b/net/rds/ib_frmr.c

@@ -133,12 +133,15 @@ static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
 
 	ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
 				&off, PAGE_SIZE);
-	if (unlikely(ret != ibmr->sg_dma_len))
-		return ret < 0 ? ret : -EINVAL;
+	if (unlikely(ret != ibmr->sg_dma_len)) {
+		ret = ret < 0 ? ret : -EINVAL;
+		goto out_inc;
+	}
 
-	if (cmpxchg(&frmr->fr_state,
-		    FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE)
-		return -EBUSY;
+	if (cmpxchg(&frmr->fr_state, FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE) {
+		ret = -EBUSY;
+		goto out_inc;
+	}
 
 	atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
 

@@ -178,9 +181,11 @@ static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
 	 * being accessed while registration is still pending.
 	 */
 	wait_event(frmr->fr_reg_done, !frmr->fr_reg);
-
 out:
+	return ret;
 
+out_inc:
+	atomic_inc(&ibmr->ic->i_fastreg_wrs);
 	return ret;
 }
 

-- 
2.43.5

On 9/4/25 1:50 PM, Håkon Bugge wrote:

We need to increment i_fastreg_wrs before we bail out from
rds_ib_post_reg_frmr().

Fixes: 1659185fb4d0 ("RDS: IB: Support Fastreg MR (FRMR) memory registration mode")
Fixes: 3a2886cca703 ("net/rds: Keep track of and wait for FRWR segments in use upon shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Håkon Bugge <redacted>

whoops, I replied to v1 by mistake:

https://lore.kernel.org/netdev/d918e832-c2ef-4fc8-864f-407bbcf06073@redhat.com/T/#mb92f279c773d443313f9e0951a2107060078802c

But the comments apply here as well.

Thanks,

Paolo