From: Håkon Bugge Date: Thu, 11 Sep 2025 13:33:34 +0000 (+0200) Subject: rds: ib: Increment i_fastreg_wrs before bailing out X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4351ca3fcb3ffecf12631b4996bf085a2dad0db6;p=users%2Fjedix%2Flinux-maple.git 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(). We have a fixed budget of how many FRWR operations that can be outstanding using the dedicated QP used for memory registrations and de-registrations. This budget is enforced by the atomic_t i_fastreg_wrs. If we bail out early in rds_ib_post_reg_frmr(), we will "leak" the possibility of posting an FRWR operation, and if that accumulates, no FRWR operation can be carried out. 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 Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20250911133336.451212-1-haakon.bugge@oracle.com Signed-off-by: Jakub Kicinski --- diff --git a/net/rds/ib_frmr.c b/net/rds/ib_frmr.c index 28c1b0022178..bd861191157b 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); @@ -166,11 +169,10 @@ static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr) /* Failure here can be because of -ENOMEM as well */ rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE); - atomic_inc(&ibmr->ic->i_fastreg_wrs); if (printk_ratelimit()) pr_warn("RDS/IB: %s returned error(%d)\n", __func__, ret); - goto out; + goto out_inc; } /* Wait for the registration to complete in order to prevent an invalid @@ -179,8 +181,10 @@ static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr) */ wait_event(frmr->fr_reg_done, !frmr->fr_reg); -out: + return ret; +out_inc: + atomic_inc(&ibmr->ic->i_fastreg_wrs); return ret; }