diff mbox series

cifs: set length when cifs_copy_pages_to_iter is successful

Message ID 20220526140226.2648689-1-trix@redhat.com (mailing list archive)
State New, archived
Headers show
Series cifs: set length when cifs_copy_pages_to_iter is successful | expand

Commit Message

Tom Rix May 26, 2022, 2:02 p.m. UTC
clang build fails with
fs/cifs/smb2ops.c:4984:7: error: variable 'length' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
  if (rdata->result != 0) {
      ^~~~~~~~~~~~~~~~~~

handle_read_data() returns the number of bytes handled by setting the length variable.
This only happens in the copy_to_iter() branch, it needs to also happen in the
cifs_copy_pages_to_iter() branch.  When cifs_copy_pages_to_iter() is successful,
its parameter data_len is how many bytes were handled, so set length to data_len.

Fixes: 67fd8cff2b0f ("cifs: Change the I/O paths to use an iterator rather than a page list")
Signed-off-by: Tom Rix <trix@redhat.com>
---
 fs/cifs/smb2ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Nick Desaulniers May 27, 2022, 7:32 p.m. UTC | #1
+ Steve's @microsoft.com email addr.

On Thu, May 26, 2022 at 7:02 AM Tom Rix <trix@redhat.com> wrote:
>
> clang build fails with
> fs/cifs/smb2ops.c:4984:7: error: variable 'length' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>   if (rdata->result != 0) {
>       ^~~~~~~~~~~~~~~~~~
>
> handle_read_data() returns the number of bytes handled by setting the length variable.
> This only happens in the copy_to_iter() branch, it needs to also happen in the
> cifs_copy_pages_to_iter() branch.  When cifs_copy_pages_to_iter() is successful,
> its parameter data_len is how many bytes were handled, so set length to data_len.
>
> Fixes: 67fd8cff2b0f ("cifs: Change the I/O paths to use an iterator rather than a page list")
> Signed-off-by: Tom Rix <trix@redhat.com>
> ---
>  fs/cifs/smb2ops.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 3630e132781f..bfad482ec186 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -4988,7 +4988,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
>                                 dequeue_mid(mid, rdata->result);
>                         return 0;
>                 }
> -               rdata->got_bytes = pages_len;
> +               length = rdata->got_bytes = pages_len;
>
>         } else if (buf_len >= data_offset + data_len) {
>                 /* read response payload is in buf */
> --
> 2.27.0
>
Steve French May 28, 2022, 11:31 p.m. UTC | #2
Presumably this was in Dave Howell's patch set which we took out of
for-next to restructure in some of Al's feedback and some things found
during testing. So nothing to fix in current mainline or for-next ...
right?

On Sat, May 28, 2022 at 3:40 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> + Steve's @microsoft.com email addr.
>
> On Thu, May 26, 2022 at 7:02 AM Tom Rix <trix@redhat.com> wrote:
> >
> > clang build fails with
> > fs/cifs/smb2ops.c:4984:7: error: variable 'length' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> >   if (rdata->result != 0) {
> >       ^~~~~~~~~~~~~~~~~~
> >
> > handle_read_data() returns the number of bytes handled by setting the length variable.
> > This only happens in the copy_to_iter() branch, it needs to also happen in the
> > cifs_copy_pages_to_iter() branch.  When cifs_copy_pages_to_iter() is successful,
> > its parameter data_len is how many bytes were handled, so set length to data_len.
> >
> > Fixes: 67fd8cff2b0f ("cifs: Change the I/O paths to use an iterator rather than a page list")
> > Signed-off-by: Tom Rix <trix@redhat.com>
> > ---
> >  fs/cifs/smb2ops.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> > index 3630e132781f..bfad482ec186 100644
> > --- a/fs/cifs/smb2ops.c
> > +++ b/fs/cifs/smb2ops.c
> > @@ -4988,7 +4988,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
> >                                 dequeue_mid(mid, rdata->result);
> >                         return 0;
> >                 }
> > -               rdata->got_bytes = pages_len;
> > +               length = rdata->got_bytes = pages_len;
> >
> >         } else if (buf_len >= data_offset + data_len) {
> >                 /* read response payload is in buf */
> > --
> > 2.27.0
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
Tom Rix May 29, 2022, 12:52 p.m. UTC | #3
On 5/28/22 4:31 PM, Steve French wrote:
> Presumably this was in Dave Howell's patch set which we took out of
> for-next to restructure in some of Al's feedback and some things found
> during testing. So nothing to fix in current mainline or for-next ...
> right?

Yup. Nothing to fix.

So drop this patch.

Tom

>
> On Sat, May 28, 2022 at 3:40 PM Nick Desaulniers
> <ndesaulniers@google.com> wrote:
>> + Steve's @microsoft.com email addr.
>>
>> On Thu, May 26, 2022 at 7:02 AM Tom Rix <trix@redhat.com> wrote:
>>> clang build fails with
>>> fs/cifs/smb2ops.c:4984:7: error: variable 'length' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>>>    if (rdata->result != 0) {
>>>        ^~~~~~~~~~~~~~~~~~
>>>
>>> handle_read_data() returns the number of bytes handled by setting the length variable.
>>> This only happens in the copy_to_iter() branch, it needs to also happen in the
>>> cifs_copy_pages_to_iter() branch.  When cifs_copy_pages_to_iter() is successful,
>>> its parameter data_len is how many bytes were handled, so set length to data_len.
>>>
>>> Fixes: 67fd8cff2b0f ("cifs: Change the I/O paths to use an iterator rather than a page list")
>>> Signed-off-by: Tom Rix <trix@redhat.com>
>>> ---
>>>   fs/cifs/smb2ops.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
>>> index 3630e132781f..bfad482ec186 100644
>>> --- a/fs/cifs/smb2ops.c
>>> +++ b/fs/cifs/smb2ops.c
>>> @@ -4988,7 +4988,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
>>>                                  dequeue_mid(mid, rdata->result);
>>>                          return 0;
>>>                  }
>>> -               rdata->got_bytes = pages_len;
>>> +               length = rdata->got_bytes = pages_len;
>>>
>>>          } else if (buf_len >= data_offset + data_len) {
>>>                  /* read response payload is in buf */
>>> --
>>> 2.27.0
>>>
>>
>> --
>> Thanks,
>> ~Nick Desaulniers
>
>
diff mbox series

Patch

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 3630e132781f..bfad482ec186 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -4988,7 +4988,7 @@  handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 				dequeue_mid(mid, rdata->result);
 			return 0;
 		}
-		rdata->got_bytes = pages_len;
+		length = rdata->got_bytes = pages_len;
 
 	} else if (buf_len >= data_offset + data_len) {
 		/* read response payload is in buf */