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/mount.h>
16#include <asm/current.h>
17#include <asm/uaccess.h>
18
19
20long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
21{
22	struct inode *inode = file_inode(filp);
23	struct ext2_inode_info *ei = EXT2_I(inode);
24	unsigned int flags;
25	unsigned short rsv_window_size;
26	int ret;
27
28	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
29
30	switch (cmd) {
31	case EXT2_IOC_GETFLAGS:
32		ext2_get_inode_flags(ei);
33		flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
34		return put_user(flags, (int __user *) arg);
35	case EXT2_IOC_SETFLAGS: {
36		unsigned int oldflags;
37
38		ret = mnt_want_write_file(filp);
39		if (ret)
40			return ret;
41
42		if (!inode_owner_or_capable(inode)) {
43			ret = -EACCES;
44			goto setflags_out;
45		}
46
47		if (get_user(flags, (int __user *) arg)) {
48			ret = -EFAULT;
49			goto setflags_out;
50		}
51
52		flags = ext2_mask_flags(inode->i_mode, flags);
53
54		mutex_lock(&inode->i_mutex);
55		/* Is it quota file? Do not allow user to mess with it */
56		if (IS_NOQUOTA(inode)) {
57			mutex_unlock(&inode->i_mutex);
58			ret = -EPERM;
59			goto setflags_out;
60		}
61		oldflags = ei->i_flags;
62
63		/*
64		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
65		 * the relevant capability.
66		 *
67		 * This test looks nicer. Thanks to Pauline Middelink
68		 */
69		if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
70			if (!capable(CAP_LINUX_IMMUTABLE)) {
71				mutex_unlock(&inode->i_mutex);
72				ret = -EPERM;
73				goto setflags_out;
74			}
75		}
76
77		flags = flags & EXT2_FL_USER_MODIFIABLE;
78		flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
79		ei->i_flags = flags;
80
81		ext2_set_inode_flags(inode);
82		inode->i_ctime = CURRENT_TIME_SEC;
83		mutex_unlock(&inode->i_mutex);
84
85		mark_inode_dirty(inode);
86setflags_out:
87		mnt_drop_write_file(filp);
88		return ret;
89	}
90	case EXT2_IOC_GETVERSION:
91		return put_user(inode->i_generation, (int __user *) arg);
92	case EXT2_IOC_SETVERSION: {
93		__u32 generation;
94
95		if (!inode_owner_or_capable(inode))
96			return -EPERM;
97		ret = mnt_want_write_file(filp);
98		if (ret)
99			return ret;
100		if (get_user(generation, (int __user *) arg)) {
101			ret = -EFAULT;
102			goto setversion_out;
103		}
104
105		mutex_lock(&inode->i_mutex);
106		inode->i_ctime = CURRENT_TIME_SEC;
107		inode->i_generation = generation;
108		mutex_unlock(&inode->i_mutex);
109
110		mark_inode_dirty(inode);
111setversion_out:
112		mnt_drop_write_file(filp);
113		return ret;
114	}
115	case EXT2_IOC_GETRSVSZ:
116		if (test_opt(inode->i_sb, RESERVATION)
117			&& S_ISREG(inode->i_mode)
118			&& ei->i_block_alloc_info) {
119			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
120			return put_user(rsv_window_size, (int __user *)arg);
121		}
122		return -ENOTTY;
123	case EXT2_IOC_SETRSVSZ: {
124
125		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
126			return -ENOTTY;
127
128		if (!inode_owner_or_capable(inode))
129			return -EACCES;
130
131		if (get_user(rsv_window_size, (int __user *)arg))
132			return -EFAULT;
133
134		ret = mnt_want_write_file(filp);
135		if (ret)
136			return ret;
137
138		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
139			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
140
141		/*
142		 * need to allocate reservation structure for this inode
143		 * before set the window size
144		 */
145		/*
146		 * XXX What lock should protect the rsv_goal_size?
147		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
148		 */
149		mutex_lock(&ei->truncate_mutex);
150		if (!ei->i_block_alloc_info)
151			ext2_init_block_alloc_info(inode);
152
153		if (ei->i_block_alloc_info){
154			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
155			rsv->rsv_goal_size = rsv_window_size;
156		}
157		mutex_unlock(&ei->truncate_mutex);
158		mnt_drop_write_file(filp);
159		return 0;
160	}
161	default:
162		return -ENOTTY;
163	}
164}
165
166#ifdef CONFIG_COMPAT
167long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
168{
169	/* These are just misnamed, they actually get/put from/to user an int */
170	switch (cmd) {
171	case EXT2_IOC32_GETFLAGS:
172		cmd = EXT2_IOC_GETFLAGS;
173		break;
174	case EXT2_IOC32_SETFLAGS:
175		cmd = EXT2_IOC_SETFLAGS;
176		break;
177	case EXT2_IOC32_GETVERSION:
178		cmd = EXT2_IOC_GETVERSION;
179		break;
180	case EXT2_IOC32_SETVERSION:
181		cmd = EXT2_IOC_SETVERSION;
182		break;
183	default:
184		return -ENOIOCTLCMD;
185	}
186	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
187}
188#endif
189