Messages in this thread | | | Date | Wed, 23 Feb 2022 09:49:15 +0100 | Subject | Re: [PATCH] debugfs: Document that debugfs_create functions need not be error checked | From | Javier Martinez Canillas <> |
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Hello Doug,
On 2/23/22 00:46, Douglas Anderson wrote: > As talked about in commit b792e64021ec ("drm: no need to check return > value of debugfs_create functions"), in many cases we can get away > with totally skipping checking the errors of debugfs functions. Let's > document that so people don't add new code that needlessly checks > these errors. > > Probably this note could be added to a boatload of functions, but > that's a lot of duplication. Let's just add it to the two most > frequent ones and hope people will get the idea. >
Agreed. The first contact point for folks looking for the function's return values will probably be these two, I second that is enough.
> Suggested-by: Javier Martinez Canillas <javierm@redhat.com> > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > > fs/debugfs/inode.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c > index 2f117c57160d..3dcf0b8b4e93 100644 > --- a/fs/debugfs/inode.c > +++ b/fs/debugfs/inode.c > @@ -450,6 +450,11 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode, > * > * If debugfs is not enabled in the kernel, the value -%ENODEV will be > * returned. > + * > + * NOTE: it's expected that most callers should _ignore_ the errors returned > + * by this function. Other debugfs functions handle the fact that the "dentry" > + * passed to them could be an error and they don't crash in that case. > + * Drivers should generally work fine even if debugfs fails to init anyway. > */
Thanks a lot for adding this. I was confused why the kernel doc didn't mention anything like that, yet most drivers didn't check and just ignored the errors.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Best regards, -- Javier Martinez Canillas Linux Engineering Red Hat
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