Message ID | 20201203135855.70136-1-alex.chen@huawei.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [v2] qemu-nbd: Fix a memleak in nbd_client_thread() | expand |
03.12.2020 16:58, Alex Chen wrote: > When the qio_channel_socket_connect_sync() fails > we should goto 'out_socket' label to free the 'sioc' instead of > goto 'out' label. > In addition, there's a lot of redundant code in the successful branch > and the error branch, optimize it. > > Reported-by: Euler Robot <euler.robot@huawei.com> > Signed-off-by: Alex Chen <alex.chen@huawei.com> > Signed-off-by: Eric Blake <eblake@redhat.com> > --- > qemu-nbd.c | 38 +++++++++++++++----------------------- > 1 file changed, 15 insertions(+), 23 deletions(-) > > diff --git a/qemu-nbd.c b/qemu-nbd.c > index a7075c5419..9583ee1af6 100644 > --- a/qemu-nbd.c > +++ b/qemu-nbd.c > @@ -265,8 +265,8 @@ static void *nbd_client_thread(void *arg) > char *device = arg; > NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") }; > QIOChannelSocket *sioc; > - int fd; > - int ret; > + int fd = -1; > + int ret = EXIT_FAILURE; > pthread_t show_parts_thread; > Error *local_error = NULL; > > @@ -278,26 +278,24 @@ static void *nbd_client_thread(void *arg) > goto out; > } > > - ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), > - NULL, NULL, NULL, &info, &local_error); > - if (ret < 0) { > + if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), > + NULL, NULL, NULL, &info, &local_error) < 0) { > if (local_error) { > error_report_err(local_error); > } > - goto out_socket; > + goto out; > } > > fd = open(device, O_RDWR); > if (fd < 0) { > /* Linux-only, we can use %m in printf. */ > error_report("Failed to open %s: %m", device); > - goto out_socket; > + goto out; > } > > - ret = nbd_init(fd, sioc, &info, &local_error); > - if (ret < 0) { > + if (nbd_init(fd, sioc, &info, &local_error) < 0) { > error_report_err(local_error); > - goto out_fd; > + goto out; > } > > /* update partition table */ > @@ -311,24 +309,18 @@ static void *nbd_client_thread(void *arg) > dup2(STDOUT_FILENO, STDERR_FILENO); > } > > - ret = nbd_client(fd); > - if (ret) { > - goto out_fd; > + if (nbd_client(fd) == 0) { > + ret = EXIT_SUCCESS; It's not obvious that nbd_client() returns 0 on success, it calls ioctl(), which may return something positive in theory.. So, with s/==/>=/, or with just if (nbd_client(fd) < 0) { goto out; } ret = EXIT_SUCCESS; (which is good common pattern I think) : Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
On 2020/12/8 21:41, Vladimir Sementsov-Ogievskiy wrote: > 03.12.2020 16:58, Alex Chen wrote: >> When the qio_channel_socket_connect_sync() fails >> we should goto 'out_socket' label to free the 'sioc' instead of >> goto 'out' label. >> In addition, there's a lot of redundant code in the successful branch >> and the error branch, optimize it. >> >> Reported-by: Euler Robot <euler.robot@huawei.com> >> Signed-off-by: Alex Chen <alex.chen@huawei.com> >> Signed-off-by: Eric Blake <eblake@redhat.com> >> --- >> qemu-nbd.c | 38 +++++++++++++++----------------------- >> 1 file changed, 15 insertions(+), 23 deletions(-) >> >> diff --git a/qemu-nbd.c b/qemu-nbd.c >> index a7075c5419..9583ee1af6 100644 >> --- a/qemu-nbd.c >> +++ b/qemu-nbd.c >> @@ -265,8 +265,8 @@ static void *nbd_client_thread(void *arg) >> char *device = arg; >> NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") }; >> QIOChannelSocket *sioc; >> - int fd; >> - int ret; >> + int fd = -1; >> + int ret = EXIT_FAILURE; >> pthread_t show_parts_thread; >> Error *local_error = NULL; >> @@ -278,26 +278,24 @@ static void *nbd_client_thread(void *arg) >> goto out; >> } >> - ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), >> - NULL, NULL, NULL, &info, &local_error); >> - if (ret < 0) { >> + if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), >> + NULL, NULL, NULL, &info, &local_error) < 0) { >> if (local_error) { >> error_report_err(local_error); >> } >> - goto out_socket; >> + goto out; >> } >> fd = open(device, O_RDWR); >> if (fd < 0) { >> /* Linux-only, we can use %m in printf. */ >> error_report("Failed to open %s: %m", device); >> - goto out_socket; >> + goto out; >> } >> - ret = nbd_init(fd, sioc, &info, &local_error); >> - if (ret < 0) { >> + if (nbd_init(fd, sioc, &info, &local_error) < 0) { >> error_report_err(local_error); >> - goto out_fd; >> + goto out; >> } >> /* update partition table */ >> @@ -311,24 +309,18 @@ static void *nbd_client_thread(void *arg) >> dup2(STDOUT_FILENO, STDERR_FILENO); >> } >> - ret = nbd_client(fd); >> - if (ret) { >> - goto out_fd; >> + if (nbd_client(fd) == 0) { >> + ret = EXIT_SUCCESS; > > It's not obvious that nbd_client() returns 0 on success, it calls ioctl(), which may return something positive in theory.. > > So, with s/==/>=/, or with just > > if (nbd_client(fd) < 0) { > goto out; > } > > ret = EXIT_SUCCESS; > > > (which is good common pattern I think) > > : > Thanks for your review, I will fix it and send patch v3. Thanks, Alex
diff --git a/qemu-nbd.c b/qemu-nbd.c index a7075c5419..9583ee1af6 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -265,8 +265,8 @@ static void *nbd_client_thread(void *arg) char *device = arg; NBDExportInfo info = { .request_sizes = false, .name = g_strdup("") }; QIOChannelSocket *sioc; - int fd; - int ret; + int fd = -1; + int ret = EXIT_FAILURE; pthread_t show_parts_thread; Error *local_error = NULL; @@ -278,26 +278,24 @@ static void *nbd_client_thread(void *arg) goto out; } - ret = nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), - NULL, NULL, NULL, &info, &local_error); - if (ret < 0) { + if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc), + NULL, NULL, NULL, &info, &local_error) < 0) { if (local_error) { error_report_err(local_error); } - goto out_socket; + goto out; } fd = open(device, O_RDWR); if (fd < 0) { /* Linux-only, we can use %m in printf. */ error_report("Failed to open %s: %m", device); - goto out_socket; + goto out; } - ret = nbd_init(fd, sioc, &info, &local_error); - if (ret < 0) { + if (nbd_init(fd, sioc, &info, &local_error) < 0) { error_report_err(local_error); - goto out_fd; + goto out; } /* update partition table */ @@ -311,24 +309,18 @@ static void *nbd_client_thread(void *arg) dup2(STDOUT_FILENO, STDERR_FILENO); } - ret = nbd_client(fd); - if (ret) { - goto out_fd; + if (nbd_client(fd) == 0) { + ret = EXIT_SUCCESS; } - close(fd); - object_unref(OBJECT(sioc)); - g_free(info.name); - kill(getpid(), SIGTERM); - return (void *) EXIT_SUCCESS; -out_fd: - close(fd); -out_socket: + out: + if (fd >= 0) { + close(fd); + } object_unref(OBJECT(sioc)); -out: g_free(info.name); kill(getpid(), SIGTERM); - return (void *) EXIT_FAILURE; + return (void *) (intptr_t) ret; } #endif /* HAVE_NBD_DEVICE */