Re: [PATCH 4/5] alpha: simplify osf_mount

From: Guenter Roeck
Date: Sun Oct 11 2020 - 10:23:01 EST


On Thu, Sep 17, 2020 at 10:22:35AM +0200, Christoph Hellwig wrote:
> Merge the mount_args structures and mount helpers to simplify the code a
> bit.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> arch/alpha/kernel/osf_sys.c | 111 +++++++++---------------------------
> 1 file changed, 28 insertions(+), 83 deletions(-)
>
> diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
> index d5367a1c6300c1..5fd155b13503b5 100644
> --- a/arch/alpha/kernel/osf_sys.c
> +++ b/arch/alpha/kernel/osf_sys.c
> @@ -421,109 +421,54 @@ SYSCALL_DEFINE3(osf_fstatfs64, unsigned long, fd,
> *
> * Although to be frank, neither are the native Linux/i386 ones..
> */
> -struct ufs_args {
> +struct osf_mount_args {
> char __user *devname;
> int flags;
> uid_t exroot;
> + /* this has lots more here for cdfs at least, but we don't bother */
> };
>
> -struct cdfs_args {
> - char __user *devname;
> - int flags;
> - uid_t exroot;
> -
> - /* This has lots more here, which Linux handles with the option block
> - but I'm too lazy to do the translation into ASCII. */
> -};
> -
> -struct procfs_args {
> - char __user *devname;
> - int flags;
> - uid_t exroot;
> -};
> -
> -/*
> - * We can't actually handle ufs yet, so we translate UFS mounts to
> - * ext2fs mounts. I wouldn't mind a UFS filesystem, but the UFS
> - * layout is so braindead it's a major headache doing it.
> - *
> - * Just how long ago was it written? OTOH our UFS driver may be still
> - * unhappy with OSF UFS. [CHECKME]
> - */
> -static int
> -osf_ufs_mount(const char __user *dirname,
> - struct ufs_args __user *args, int flags)
> +SYSCALL_DEFINE4(osf_mount, unsigned long, typenr, const char __user *, path,
> + int, flag, void __user *, data)
> {
> - int retval;
> - struct cdfs_args tmp;
> + struct osf_mount_args tmp;
> struct filename *devname;
> -
> - retval = -EFAULT;
> - if (copy_from_user(&tmp, args, sizeof(tmp)))
> - goto out;
> - devname = getname(tmp.devname);
> - retval = PTR_ERR(devname);
> - if (IS_ERR(devname))
> - goto out;
> - retval = do_mount(devname->name, dirname, "ext2", flags, NULL);
> - putname(devname);
> - out:
> - return retval;
> -}
> -
> -static int
> -osf_cdfs_mount(const char __user *dirname,
> - struct cdfs_args __user *args, int flags)
> -{
> + const char *fstype;
> int retval;
> - struct cdfs_args tmp;
> - struct filename *devname;
> -
> - retval = -EFAULT;
> - if (copy_from_user(&tmp, args, sizeof(tmp)))
> - goto out;
> - devname = getname(tmp.devname);
> - retval = PTR_ERR(devname);
> - if (IS_ERR(devname))
> - goto out;
> - retval = do_mount(devname->name, dirname, "iso9660", flags, NULL);
> - putname(devname);
> - out:
> - return retval;
> -}
> -
> -static int
> -osf_procfs_mount(const char __user *dirname,
> - struct procfs_args __user *args, int flags)
> -{
> - struct procfs_args tmp;
>
> if (copy_from_user(&tmp, args, sizeof(tmp)))
> return -EFAULT;
>
arch/alpha/kernel/osf_sys.c:440:27: error: 'args' undeclared (first use in this function)

> - return do_mount("", dirname, "proc", flags, NULL);
> -}
> -
> -SYSCALL_DEFINE4(osf_mount, unsigned long, typenr, const char __user *, path,
> - int, flag, void __user *, data)
> -{
> - int retval;
> -
> switch (typenr) {
> - case 1:
> - retval = osf_ufs_mount(path, data, flag);
> + case 1: /* ufs */
> + /*
> + * We can't actually handle ufs yet, so we translate UFS mounts
> + * to ext2 mounts. I wouldn't mind a UFS filesystem, but the UFS
> + * layout is so braindead it's a major headache doing it.
> + *
> + * Just how long ago was it written? OTOH our UFS driver may be
> + * still unhappy with OSF UFS. [CHECKME]
> + */
> + fstype = "ext2";
> + devname = getname(tmp.devname);
> break;
> - case 6:
> - retval = osf_cdfs_mount(path, data, flag);
> + case 6: /* cdfs */
> + fstype = "iso9660";
> + devname = getname(tmp.devname);
> break;
> - case 9:
> - retval = osf_procfs_mount(path, data, flag);
> + case 9: /* procfs */
> + fstype = "proc";
> + devname = getname_kernel("");
> break;
> default:
> - retval = -EINVAL;
> printk("osf_mount(%ld, %x)\n", typenr, flag);
> + return -EINVAL;
> }
>
> + if (IS_ERR(devname))
> + return PTR_ERR(devname);
> + retval = do_mount(devname.name, dirname, fstype, flags, NULL);

arch/alpha/kernel/osf_sys.c:471:34: error:
'dirname' undeclared (first use in this function); did you mean 'devname'?

> + putname(devname);
> return retval;
> }
>