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549c729771
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Pioctl operations for Coda.
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* Original version: (C) 1996 Peter Braam
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* Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
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*
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* Carnegie Mellon encourages users of this code to contribute improvements
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* to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/stat.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/namei.h>
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#include <linux/module.h>
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#include <linux/uaccess.h>
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#include <linux/coda.h>
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#include "coda_psdev.h"
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#include "coda_linux.h"
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/* pioctl ops */
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static int coda_ioctl_permission(struct user_namespace *mnt_userns,
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struct inode *inode, int mask);
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static long coda_pioctl(struct file *filp, unsigned int cmd,
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unsigned long user_data);
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/* exported from this file */
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const struct inode_operations coda_ioctl_inode_operations = {
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.permission = coda_ioctl_permission,
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.setattr = coda_setattr,
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};
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const struct file_operations coda_ioctl_operations = {
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.unlocked_ioctl = coda_pioctl,
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.llseek = noop_llseek,
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};
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/* the coda pioctl inode ops */
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static int coda_ioctl_permission(struct user_namespace *mnt_userns,
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struct inode *inode, int mask)
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{
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return (mask & MAY_EXEC) ? -EACCES : 0;
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}
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static long coda_pioctl(struct file *filp, unsigned int cmd,
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unsigned long user_data)
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{
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struct path path;
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int error;
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struct PioctlData data;
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struct inode *inode = file_inode(filp);
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struct inode *target_inode = NULL;
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struct coda_inode_info *cnp;
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/* get the Pioctl data arguments from user space */
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if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
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return -EINVAL;
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/*
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* Look up the pathname. Note that the pathname is in
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* user memory, and namei takes care of this
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*/
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error = user_path_at(AT_FDCWD, data.path,
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data.follow ? LOOKUP_FOLLOW : 0, &path);
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if (error)
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return error;
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target_inode = d_inode(path.dentry);
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/* return if it is not a Coda inode */
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if (target_inode->i_sb != inode->i_sb) {
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error = -EINVAL;
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goto out;
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}
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/* now proceed to make the upcall */
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cnp = ITOC(target_inode);
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error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
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out:
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path_put(&path);
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return error;
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}
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