1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Pioctl operations for Coda. 4 * Original version: (C) 1996 Peter Braam 5 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University 6 * 7 * Carnegie Mellon encourages users of this code to contribute improvements 8 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. 9 */ 10 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/time.h> 14 #include <linux/fs.h> 15 #include <linux/stat.h> 16 #include <linux/errno.h> 17 #include <linux/string.h> 18 #include <linux/namei.h> 19 #include <linux/module.h> 20 #include <linux/uaccess.h> 21 22 #include <linux/coda.h> 23 #include "coda_psdev.h" 24 #include "coda_linux.h" 25 26 /* pioctl ops */ 27 static int coda_ioctl_permission(struct user_namespace *mnt_userns, 28 struct inode *inode, int mask); 29 static long coda_pioctl(struct file *filp, unsigned int cmd, 30 unsigned long user_data); 31 32 /* exported from this file */ 33 const struct inode_operations coda_ioctl_inode_operations = { 34 .permission = coda_ioctl_permission, 35 .setattr = coda_setattr, 36 }; 37 38 const struct file_operations coda_ioctl_operations = { 39 .unlocked_ioctl = coda_pioctl, 40 .llseek = noop_llseek, 41 }; 42 43 /* the coda pioctl inode ops */ 44 static int coda_ioctl_permission(struct user_namespace *mnt_userns, 45 struct inode *inode, int mask) 46 { 47 return (mask & MAY_EXEC) ? -EACCES : 0; 48 } 49 50 static long coda_pioctl(struct file *filp, unsigned int cmd, 51 unsigned long user_data) 52 { 53 struct path path; 54 int error; 55 struct PioctlData data; 56 struct inode *inode = file_inode(filp); 57 struct inode *target_inode = NULL; 58 struct coda_inode_info *cnp; 59 60 /* get the Pioctl data arguments from user space */ 61 if (copy_from_user(&data, (void __user *)user_data, sizeof(data))) 62 return -EINVAL; 63 64 /* 65 * Look up the pathname. Note that the pathname is in 66 * user memory, and namei takes care of this 67 */ 68 error = user_path_at(AT_FDCWD, data.path, 69 data.follow ? LOOKUP_FOLLOW : 0, &path); 70 if (error) 71 return error; 72 73 target_inode = d_inode(path.dentry); 74 75 /* return if it is not a Coda inode */ 76 if (target_inode->i_sb != inode->i_sb) { 77 error = -EINVAL; 78 goto out; 79 } 80 81 /* now proceed to make the upcall */ 82 cnp = ITOC(target_inode); 83 84 error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data); 85 out: 86 path_put(&path); 87 return error; 88 } 89