Re: [PATCH v2] qemu-nbd: Fix a memleak in nbd_client_thread()

2020-12-08 Thread Alex Chen 
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 
>> Signed-off-by: Alex Chen 
>> Signed-off-by: Eric Blake 
>> ---
>>   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, , _error);
>> -if (ret < 0) {
>> +if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
>> +  NULL, NULL, NULL, , _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, , _error);
>> -if (ret < 0) {
>> +if (nbd_init(fd, sioc, , _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

Re: [PATCH v2] qemu-nbd: Fix a memleak in nbd_client_thread()

2020-12-08 Thread Vladimir Sementsov-Ogievskiy 

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 
Signed-off-by: Alex Chen 
Signed-off-by: Eric Blake 
---
  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, , _error);
-if (ret < 0) {
+if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
+  NULL, NULL, NULL, , _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, , _error);

-if (ret < 0) {
+if (nbd_init(fd, sioc, , _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 

--
Best regards,
Vladimir

[PATCH v2] qemu-nbd: Fix a memleak in nbd_client_thread()

2020-12-03 Thread Alex Chen 
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 
Signed-off-by: Alex Chen 
Signed-off-by: Eric Blake 
---
 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, , _error);
-if (ret < 0) {
+if (nbd_receive_negotiate(NULL, QIO_CHANNEL(sioc),
+  NULL, NULL, NULL, , _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, , _error);
-if (ret < 0) {
+if (nbd_init(fd, sioc, , _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 */
 
-- 
2.19.1