namei: make do_symlinkat() take struct filename

Pass in the struct filename pointers instead of the user string, for
uniformity with the recently converted do_mkdnodat(), do_unlinkat(),
do_renameat(), do_mkdirat().

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/20210330071700.kpjoyp5zlni7uejm@wittgenstein/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20210708063447.3556403-6-dkadashev@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/namei.c b/fs/namei.c
index ea575dd..522c35b 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4207,23 +4207,23 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 }
 EXPORT_SYMBOL(vfs_symlink);
 
-static long do_symlinkat(const char __user *oldname, int newdfd,
-                 const char __user *newname)
+static long do_symlinkat(struct filename *from, int newdfd,
+                 struct filename *to)
 {
        int error;
-       struct filename *from;
        struct dentry *dentry;
        struct path path;
        unsigned int lookup_flags = 0;
 
-       from = getname(oldname);
-       if (IS_ERR(from))
-               return PTR_ERR(from);
+       if (IS_ERR(from)) {
+               error = PTR_ERR(from);
+               goto out_putnames;
+       }
 retry:
-       dentry = user_path_create(newdfd, newname, &path, lookup_flags);
+       dentry = __filename_create(newdfd, to, &path, lookup_flags);
        error = PTR_ERR(dentry);
        if (IS_ERR(dentry))
-               goto out_putname;
+               goto out_putnames;
 
        error = security_path_symlink(&path, dentry, from->name);
        if (!error) {
@@ -4238,7 +4238,8 @@ retry:
                lookup_flags |= LOOKUP_REVAL;
                goto retry;
        }
-out_putname:
+out_putnames:
+       putname(to);
        putname(from);
        return error;
 }
@@ -4246,12 +4247,12 @@ out_putname:
 SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
                int, newdfd, const char __user *, newname)
 {
-       return do_symlinkat(oldname, newdfd, newname);
+       return do_symlinkat(getname(oldname), newdfd, getname(newname));
 }
 
 SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
 {
-       return do_symlinkat(oldname, AT_FDCWD, newname);
+       return do_symlinkat(getname(oldname), AT_FDCWD, getname(newname));
 }
 
 /**