io_uring: use files_lookup_fd_locked()

While valid we don't need to open-code rcu dereferences if we're
acquiring file_lock anyway.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20231010030615.GO800259@ZenIV
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2023-10-10 10:23:26 +02:00
parent 0ede61d858
commit 50d910d273
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2

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@ -220,7 +220,6 @@ int io_close(struct io_kiocb *req, unsigned int issue_flags)
{
struct files_struct *files = current->files;
struct io_close *close = io_kiocb_to_cmd(req, struct io_close);
struct fdtable *fdt;
struct file *file;
int ret = -EBADF;
@ -230,13 +229,7 @@ int io_close(struct io_kiocb *req, unsigned int issue_flags)
}
spin_lock(&files->file_lock);
fdt = files_fdtable(files);
if (close->fd >= fdt->max_fds) {
spin_unlock(&files->file_lock);
goto err;
}
file = rcu_dereference_protected(fdt->fd[close->fd],
lockdep_is_held(&files->file_lock));
file = files_lookup_fd_locked(files, close->fd);
if (!file || io_is_uring_fops(file)) {
spin_unlock(&files->file_lock);
goto err;