On Fri, May 05, 2023 at 04:41:55PM +0800, ye xingchen wrote:
> >>
> >> From: Ye Xingchen <ye.xingchen@xxxxxxxxxx>
> >>
> >> convert the fget()/fput() uses to fdget()/fdput().
> >What's the advantages of this?
> >
> >Thanks
> >>
> >> Signed-off-by: Ye Xingchen <ye.xingchen@xxxxxxxxxx>
> >> ---
> >> drivers/vhost/net.c | 10 +++++-----
> >> 1 file changed, 5 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> >> index ae2273196b0c..5b3fe4805182 100644
> >> --- a/drivers/vhost/net.c
> >> +++ b/drivers/vhost/net.c
> >> @@ -1466,17 +1466,17 @@ static struct ptr_ring *get_tap_ptr_ring(struct file *file)
> >>
> >> static struct socket *get_tap_socket(int fd)
> >> {
> >> - struct file *file = fget(fd);
> >> + struct fd f = fdget(fd);
> >> struct socket *sock;
> >>
> >> - if (!file)
> >> + if (!f.file)
> >> return ERR_PTR(-EBADF);
> >> - sock = tun_get_socket(file);
> >> + sock = tun_get_socket(f.file);
> >> if (!IS_ERR(sock))
> >> return sock;
> >> - sock = tap_get_socket(file);
> >> + sock = tap_get_socket(f.file);
> >> if (IS_ERR(sock))
> >> - fput(file);
> >> + fdput(f);
> >> return sock;
> >> }
> >>
> >> --
> >> 2.25.1
> >>
> fdget requires an integer type file descriptor as its parameter,
> and fget requires a pointer to the file structure as its parameter.
In which kernel?
include/linux/file.h:extern struct file *fget(unsigned int fd);
> By using the fdget function, the socket object, can be quickly
> obtained from the process's file descriptor table without
> the need to obtain the file descriptor first before passing it
> as a parameter to the fget function. This reduces unnecessary
> operations, improves system efficiency and performance.
>
> Best Regards
> Ye
