| Message ID | 20230831132546.3525721-2-armbru@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/7] migration/rdma: Fix save_page method to fail on polling error | expand |
On Thu, Aug 31, 2023 at 03:25:40PM +0200, Markus Armbruster wrote: > qemu_rdma_save_page() reports polling error with error_report(), then > succeeds anyway. This is because the variable holding the polling > status *shadows* the variable the function returns. The latter > remains zero. > > Broken since day one, and duplicated more recently. > > Fixes: 2da776db4846 (rdma: core logic) > Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid) Alas, the curse of immutable git history preserving typos in commit subjects ;) The alternative of rewriting history and breaking SHA references is worse. > Signed-off-by: Markus Armbruster <armbru@redhat.com> > --- > migration/rdma.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) Reviewed-by: Eric Blake <eblake@redhat.com>
On Thu, Aug 31, 2023 at 03:25:40PM +0200, Markus Armbruster wrote: > qemu_rdma_save_page() reports polling error with error_report(), then > succeeds anyway. This is because the variable holding the polling > status *shadows* the variable the function returns. The latter > remains zero. > > Broken since day one, and duplicated more recently. > > Fixes: 2da776db4846 (rdma: core logic) > Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid) > Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com>
On 31/08/2023 21:25, Markus Armbruster wrote: > qemu_rdma_save_page() reports polling error with error_report(), then > succeeds anyway. This is because the variable holding the polling > status *shadows* the variable the function returns. The latter > remains zero. > > Broken since day one, and duplicated more recently. > > Fixes: 2da776db4846 (rdma: core logic) > Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid) Thanks for the fixes > Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Li Zhijian <lizhijian@fujitsu.com> > --- > migration/rdma.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/migration/rdma.c b/migration/rdma.c > index ca430d319d..b2e869aced 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -3281,7 +3281,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f, > */ > while (1) { > uint64_t wr_id, wr_id_in; > - int ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL); > + ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL); > + > if (ret < 0) { > error_report("rdma migration: polling error! %d", ret); > goto err; > @@ -3296,7 +3297,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f, > > while (1) { > uint64_t wr_id, wr_id_in; > - int ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL); > + ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL); > + > if (ret < 0) { > error_report("rdma migration: polling error! %d", ret); > goto err;
Eric Blake <eblake@redhat.com> writes: > On Thu, Aug 31, 2023 at 03:25:40PM +0200, Markus Armbruster wrote: >> qemu_rdma_save_page() reports polling error with error_report(), then >> succeeds anyway. This is because the variable holding the polling >> status *shadows* the variable the function returns. The latter >> remains zero. >> >> Broken since day one, and duplicated more recently. >> >> Fixes: 2da776db4846 (rdma: core logic) >> Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid) > > Alas, the curse of immutable git history preserving typos in commit > subjects ;) "wrid" is short for "work request ID", actually. > The alternative of rewriting history and breaking SHA > references is worse. Rewriting master is a big no-no. git-note can be used to correct the record, but it has its usability issues. >> Signed-off-by: Markus Armbruster <armbru@redhat.com> >> --- >> migration/rdma.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) > > Reviewed-by: Eric Blake <eblake@redhat.com> Thanks!
diff --git a/migration/rdma.c b/migration/rdma.c index ca430d319d..b2e869aced 100644 --- a/migration/rdma.c +++ b/migration/rdma.c @@ -3281,7 +3281,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f, */ while (1) { uint64_t wr_id, wr_id_in; - int ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL); + ret = qemu_rdma_poll(rdma, rdma->recv_cq, &wr_id_in, NULL); + if (ret < 0) { error_report("rdma migration: polling error! %d", ret); goto err; @@ -3296,7 +3297,8 @@ static size_t qemu_rdma_save_page(QEMUFile *f, while (1) { uint64_t wr_id, wr_id_in; - int ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL); + ret = qemu_rdma_poll(rdma, rdma->send_cq, &wr_id_in, NULL); + if (ret < 0) { error_report("rdma migration: polling error! %d", ret); goto err;
qemu_rdma_save_page() reports polling error with error_report(), then succeeds anyway. This is because the variable holding the polling status *shadows* the variable the function returns. The latter remains zero. Broken since day one, and duplicated more recently. Fixes: 2da776db4846 (rdma: core logic) Fixes: b390afd8c50b (migration/rdma: Fix out of order wrid) Signed-off-by: Markus Armbruster <armbru@redhat.com> --- migration/rdma.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)