xref: /openbmc/linux/fs/ext2/ioctl.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 <linux/compat.h>
15 #include <linux/smp_lock.h>
16 #include <asm/current.h>
17 #include <asm/uaccess.h>
18 
19 
20 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
21 		unsigned long arg)
22 {
23 	struct ext2_inode_info *ei = EXT2_I(inode);
24 	unsigned int flags;
25 	unsigned short rsv_window_size;
26 
27 	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
28 
29 	switch (cmd) {
30 	case EXT2_IOC_GETFLAGS:
31 		ext2_get_inode_flags(ei);
32 		flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
33 		return put_user(flags, (int __user *) arg);
34 	case EXT2_IOC_SETFLAGS: {
35 		unsigned int oldflags;
36 
37 		if (IS_RDONLY(inode))
38 			return -EROFS;
39 
40 		if (!is_owner_or_cap(inode))
41 			return -EACCES;
42 
43 		if (get_user(flags, (int __user *) arg))
44 			return -EFAULT;
45 
46 		if (!S_ISDIR(inode->i_mode))
47 			flags &= ~EXT2_DIRSYNC_FL;
48 
49 		mutex_lock(&inode->i_mutex);
50 		oldflags = ei->i_flags;
51 
52 		/*
53 		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
54 		 * the relevant capability.
55 		 *
56 		 * This test looks nicer. Thanks to Pauline Middelink
57 		 */
58 		if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
59 			if (!capable(CAP_LINUX_IMMUTABLE)) {
60 				mutex_unlock(&inode->i_mutex);
61 				return -EPERM;
62 			}
63 		}
64 
65 		flags = flags & EXT2_FL_USER_MODIFIABLE;
66 		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
67 		ei->i_flags = flags;
68 		mutex_unlock(&inode->i_mutex);
69 
70 		ext2_set_inode_flags(inode);
71 		inode->i_ctime = CURRENT_TIME_SEC;
72 		mark_inode_dirty(inode);
73 		return 0;
74 	}
75 	case EXT2_IOC_GETVERSION:
76 		return put_user(inode->i_generation, (int __user *) arg);
77 	case EXT2_IOC_SETVERSION:
78 		if (!is_owner_or_cap(inode))
79 			return -EPERM;
80 		if (IS_RDONLY(inode))
81 			return -EROFS;
82 		if (get_user(inode->i_generation, (int __user *) arg))
83 			return -EFAULT;
84 		inode->i_ctime = CURRENT_TIME_SEC;
85 		mark_inode_dirty(inode);
86 		return 0;
87 	case EXT2_IOC_GETRSVSZ:
88 		if (test_opt(inode->i_sb, RESERVATION)
89 			&& S_ISREG(inode->i_mode)
90 			&& ei->i_block_alloc_info) {
91 			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
92 			return put_user(rsv_window_size, (int __user *)arg);
93 		}
94 		return -ENOTTY;
95 	case EXT2_IOC_SETRSVSZ: {
96 
97 		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
98 			return -ENOTTY;
99 
100 		if (IS_RDONLY(inode))
101 			return -EROFS;
102 
103 		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
104 			return -EACCES;
105 
106 		if (get_user(rsv_window_size, (int __user *)arg))
107 			return -EFAULT;
108 
109 		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
110 			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
111 
112 		/*
113 		 * need to allocate reservation structure for this inode
114 		 * before set the window size
115 		 */
116 		/*
117 		 * XXX What lock should protect the rsv_goal_size?
118 		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
119 		 */
120 		mutex_lock(&ei->truncate_mutex);
121 		if (!ei->i_block_alloc_info)
122 			ext2_init_block_alloc_info(inode);
123 
124 		if (ei->i_block_alloc_info){
125 			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
126 			rsv->rsv_goal_size = rsv_window_size;
127 		}
128 		mutex_unlock(&ei->truncate_mutex);
129 		return 0;
130 	}
131 	default:
132 		return -ENOTTY;
133 	}
134 }
135 
136 #ifdef CONFIG_COMPAT
137 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
138 {
139 	struct inode *inode = file->f_path.dentry->d_inode;
140 	int ret;
141 
142 	/* These are just misnamed, they actually get/put from/to user an int */
143 	switch (cmd) {
144 	case EXT2_IOC32_GETFLAGS:
145 		cmd = EXT2_IOC_GETFLAGS;
146 		break;
147 	case EXT2_IOC32_SETFLAGS:
148 		cmd = EXT2_IOC_SETFLAGS;
149 		break;
150 	case EXT2_IOC32_GETVERSION:
151 		cmd = EXT2_IOC_GETVERSION;
152 		break;
153 	case EXT2_IOC32_SETVERSION:
154 		cmd = EXT2_IOC_SETVERSION;
155 		break;
156 	default:
157 		return -ENOIOCTLCMD;
158 	}
159 	lock_kernel();
160 	ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
161 	unlock_kernel();
162 	return ret;
163 }
164 #endif
165