Messages in this thread | | | Date | Thu, 22 Sep 2022 16:29:34 +0800 | Subject | Re: [PATCH net] net/smc: Stop the CLC flow if no link to map buffers on | From | Wen Gu <> |
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On 2022/9/20 14:43, Wen Gu wrote:
> There might be a potential race between SMC-R buffer map and > link group termination. > > smc_smcr_terminate_all() | smc_connect_rdma() > -------------------------------------------------------------- > | smc_conn_create() > for links in smcibdev | > schedule links down | > | smc_buf_create() > | \- smcr_buf_map_usable_links() > | \- no usable links found, > | (rmb->mr = NULL) > | > | smc_clc_send_confirm() > | \- access conn->rmb_desc->mr[]->rkey > | (panic) > > During reboot and IB device module remove, all links will be set > down and no usable links remain in link groups. In such situation > smcr_buf_map_usable_links() should return an error and stop the > CLC flow accessing to uninitialized mr. > > Fixes: b9247544c1bc ("net/smc: convert static link ID instances to support multiple links") > Signed-off-by: Wen Gu <guwen@linux.alibaba.com> > --- > net/smc/smc_core.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c > index ebf56cd..df89c2e 100644 > --- a/net/smc/smc_core.c > +++ b/net/smc/smc_core.c > @@ -2239,7 +2239,7 @@ static struct smc_buf_desc *smcr_new_buf_create(struct smc_link_group *lgr, > static int smcr_buf_map_usable_links(struct smc_link_group *lgr, > struct smc_buf_desc *buf_desc, bool is_rmb) > { > - int i, rc = 0; > + int i, rc = 0, cnt = 0; > > /* protect against parallel link reconfiguration */ > mutex_lock(&lgr->llc_conf_mutex); > @@ -2252,9 +2252,12 @@ static int smcr_buf_map_usable_links(struct smc_link_group *lgr, > rc = -ENOMEM; > goto out; > } > + cnt++; > } > out: > mutex_unlock(&lgr->llc_conf_mutex); > + if (!rc && !cnt) > + rc = -EINVAL; > return rc; > } >
Any comments or reviews are welcome and appreciated.
Thanks, Wen Gu
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