lkml.org 
[lkml]   [2019]   [Dec]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 1/3] vfs, fdtable: Add get_task_file helper
On Mon, Dec 23, 2019 at 10:26:46PM +0100, Christian Brauner wrote:
> On Mon, Dec 23, 2019 at 09:08:55PM +0000, Sargun Dhillon wrote:
> > This introduces a function which can be used to fetch a file, given an
> > arbitrary task. As long as the user holds a reference (refcnt) to the
> > task_struct it is safe to call, and will either return NULL on failure,
> > or a pointer to the file, with a refcnt.
> >
> > Signed-off-by: Sargun Dhillon <sargun@sargun.me>

Could you please add:

Suggested-by: Oleg Nesterov <oleg@redhat.com>

and add a line like:

"This is based on a patch sent by Oleg (cf. [1]) a while ago."

[1]: Link: https://lore.kernel.org/r/20180915160423.GA31461@redhat.com

apart from a few nits below:

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>

> > ---
> > fs/file.c | 22 ++++++++++++++++++++--
> > include/linux/file.h | 2 ++
> > 2 files changed, 22 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/file.c b/fs/file.c
> > index 2f4fcf985079..0ceeb046f4f3 100644
> > --- a/fs/file.c
> > +++ b/fs/file.c
> > @@ -706,9 +706,9 @@ void do_close_on_exec(struct files_struct *files)
> > spin_unlock(&files->file_lock);
> > }
> >
> > -static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs)
> > +static struct file *__fget_files(struct files_struct *files, unsigned int fd,
> > + fmode_t mask, unsigned int refs)
> > {
> > - struct files_struct *files = current->files;
> > struct file *file;
> >
> > rcu_read_lock();
> > @@ -729,6 +729,11 @@ static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs)
> > return file;
> > }
> >
> > +static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs)

This can be:

static inline struct file *__fget(...)

> > +{
> > + return __fget_files(current->files, fd, mask, refs);
> > +}
> > +
> > struct file *fget_many(unsigned int fd, unsigned int refs)
> > {
> > return __fget(fd, FMODE_PATH, refs);
> > @@ -746,6 +751,19 @@ struct file *fget_raw(unsigned int fd)
> > }
> > EXPORT_SYMBOL(fget_raw);
> >
> > +struct file *fget_task(struct task_struct *task, unsigned int fd)
> > +{
> > + struct file *file = NULL;
> > +
> > + task_lock(task);
> > + if (task->files)
> > + file = __fget_files(task->files, fd, 0, 1);
> > +
> > + task_unlock(task);
>
> Nit: remove the \n:
>
> task_lock(task);
> if (task->files)
> file = __fget_files(task->files, fd, 0, 1);
> task_unlock(task);
>
> Christian

\
 
 \ /
  Last update: 2019-12-25 17:21    [W:0.028 / U:1.512 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site