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rds: ib: Increment i_fastreg_wrs before bailing out

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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 <haakon.bugge@oracle.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Link: https://patch.msgid.link/20250911133336.451212-1-haakon.bugge@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Håkon Bugge 2025-09-11 15:33:34 +02:00 committed by Jakub Kicinski
parent 2e5fb2ff31
commit 4351ca3fcb
1 changed files with 12 additions and 8 deletions
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20
net/rds/ib_frmr.c
View File

@ -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;
}