xref: /linux/fs/ext2/ioctl.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  * linux/fs/ext2/ioctl.c
3  *
4  * Copyright (C) 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  */
9 
10 #include "ext2.h"
11 #include <linux/capability.h>
12 #include <linux/time.h>
13 #include <linux/sched.h>
14 #include <asm/current.h>
15 #include <asm/uaccess.h>
16 
17 
18 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
19 		unsigned long arg)
20 {
21 	struct ext2_inode_info *ei = EXT2_I(inode);
22 	unsigned int flags;
23 
24 	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
25 
26 	switch (cmd) {
27 	case EXT2_IOC_GETFLAGS:
28 		flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
29 		return put_user(flags, (int __user *) arg);
30 	case EXT2_IOC_SETFLAGS: {
31 		unsigned int oldflags;
32 
33 		if (IS_RDONLY(inode))
34 			return -EROFS;
35 
36 		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
37 			return -EACCES;
38 
39 		if (get_user(flags, (int __user *) arg))
40 			return -EFAULT;
41 
42 		if (!S_ISDIR(inode->i_mode))
43 			flags &= ~EXT2_DIRSYNC_FL;
44 
45 		oldflags = ei->i_flags;
46 
47 		/*
48 		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
49 		 * the relevant capability.
50 		 *
51 		 * This test looks nicer. Thanks to Pauline Middelink
52 		 */
53 		if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
54 			if (!capable(CAP_LINUX_IMMUTABLE))
55 				return -EPERM;
56 		}
57 
58 		flags = flags & EXT2_FL_USER_MODIFIABLE;
59 		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
60 		ei->i_flags = flags;
61 
62 		ext2_set_inode_flags(inode);
63 		inode->i_ctime = CURRENT_TIME_SEC;
64 		mark_inode_dirty(inode);
65 		return 0;
66 	}
67 	case EXT2_IOC_GETVERSION:
68 		return put_user(inode->i_generation, (int __user *) arg);
69 	case EXT2_IOC_SETVERSION:
70 		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
71 			return -EPERM;
72 		if (IS_RDONLY(inode))
73 			return -EROFS;
74 		if (get_user(inode->i_generation, (int __user *) arg))
75 			return -EFAULT;
76 		inode->i_ctime = CURRENT_TIME_SEC;
77 		mark_inode_dirty(inode);
78 		return 0;
79 	default:
80 		return -ENOTTY;
81 	}
82 }
83