On Thu 30-11-23 13:49:08, Christian Brauner wrote:
> Only io_uring uses __close_fd_get_file(). All it does is hide
> current->files but io_uring accesses files_struct directly right now
> anyway so it's a bit pointless. Just rename pick_file() to
> file_close_fd_locked() and let io_uring use it. Add a lockdep assert in
> there that we expect the caller to hold file_lock while we're at it.
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/file.c | 23 +++++++++--------------
> fs/internal.h | 2 +-
> io_uring/openclose.c | 2 +-
> 3 files changed, 11 insertions(+), 16 deletions(-)
>
> diff --git a/fs/file.c b/fs/file.c
> index 66f04442a384..c8eaa0b29a08 100644
> --- a/fs/file.c
> +++ b/fs/file.c
> @@ -629,19 +629,23 @@ void fd_install(unsigned int fd, struct file *file)
> EXPORT_SYMBOL(fd_install);
>
> /**
> - * pick_file - return file associatd with fd
> + * file_close_fd_locked - return file associated with fd
> * @files: file struct to retrieve file from
> * @fd: file descriptor to retrieve file for
> *
> + * Doesn't take a separate reference count.
> + *
> * Context: files_lock must be held.
> *
> * Returns: The file associated with @fd (NULL if @fd is not open)
> */
> -static struct file *pick_file(struct files_struct *files, unsigned fd)
> +struct file *file_close_fd_locked(struct files_struct *files, unsigned fd)
> {
> struct fdtable *fdt = files_fdtable(files);
> struct file *file;
>
> + lockdep_assert_held(&files->file_lock);
> +
> if (fd >= fdt->max_fds)
> return NULL;
>
> @@ -660,7 +664,7 @@ int close_fd(unsigned fd)
> struct file *file;
>
> spin_lock(&files->file_lock);
> - file = pick_file(files, fd);
> + file = file_close_fd_locked(files, fd);
> spin_unlock(&files->file_lock);
> if (!file)
> return -EBADF;
> @@ -707,7 +711,7 @@ static inline void __range_close(struct files_struct *files, unsigned int fd,
> max_fd = min(max_fd, n);
>
> for (; fd <= max_fd; fd++) {
> - file = pick_file(files, fd);
> + file = file_close_fd_locked(files, fd);
> if (file) {
> spin_unlock(&files->file_lock);
> filp_close(file, files);
> @@ -795,15 +799,6 @@ int __close_range(unsigned fd, unsigned max_fd, unsigned int flags)
> return 0;
> }
>
> -/*
> - * See file_close_fd() below, this variant assumes current->files->file_lock
> - * is held.
> - */
> -struct file *__close_fd_get_file(unsigned int fd)
> -{
> - return pick_file(current->files, fd);
> -}
> -
> /**
> * file_close_fd - return file associated with fd
> * @fd: file descriptor to retrieve file for
> @@ -818,7 +813,7 @@ struct file *file_close_fd(unsigned int fd)
> struct file *file;
>
> spin_lock(&files->file_lock);
> - file = pick_file(files, fd);
> + file = file_close_fd_locked(files, fd);
> spin_unlock(&files->file_lock);
>
> return file;
> diff --git a/fs/internal.h b/fs/internal.h
> index 273e6fd40d1b..a7469ddba9b6 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -179,7 +179,7 @@ extern struct file *do_file_open_root(const struct path *,
> const char *, const struct open_flags *);
> extern struct open_how build_open_how(int flags, umode_t mode);
> extern int build_open_flags(const struct open_how *how, struct open_flags *op);
> -extern struct file *__close_fd_get_file(unsigned int fd);
> +struct file *file_close_fd_locked(struct files_struct *files, unsigned fd);
>
> long do_sys_ftruncate(unsigned int fd, loff_t length, int small);
> int chmod_common(const struct path *path, umode_t mode);
> diff --git a/io_uring/openclose.c b/io_uring/openclose.c
> index fb73adb89067..74fc22461f48 100644
> --- a/io_uring/openclose.c
> +++ b/io_uring/openclose.c
> @@ -241,7 +241,7 @@ int io_close(struct io_kiocb *req, unsigned int issue_flags)
> return -EAGAIN;
> }
>
> - file = __close_fd_get_file(close->fd);
> + file = file_close_fd_locked(files, close->fd);
> spin_unlock(&files->file_lock);
> if (!file)
> goto err;
>
> --
> 2.42.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
