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 = filp->f_dentry->d_inode;
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(filp->f_path.mnt);
39		if (ret)
40			return ret;
41
42		if (!is_owner_or_cap(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		mutex_unlock(&inode->i_mutex);
81
82		ext2_set_inode_flags(inode);
83		inode->i_ctime = CURRENT_TIME_SEC;
84		mark_inode_dirty(inode);
85setflags_out:
86		mnt_drop_write(filp->f_path.mnt);
87		return ret;
88	}
89	case EXT2_IOC_GETVERSION:
90		return put_user(inode->i_generation, (int __user *) arg);
91	case EXT2_IOC_SETVERSION:
92		if (!is_owner_or_cap(inode))
93			return -EPERM;
94		ret = mnt_want_write(filp->f_path.mnt);
95		if (ret)
96			return ret;
97		if (get_user(inode->i_generation, (int __user *) arg)) {
98			ret = -EFAULT;
99		} else {
100			inode->i_ctime = CURRENT_TIME_SEC;
101			mark_inode_dirty(inode);
102		}
103		mnt_drop_write(filp->f_path.mnt);
104		return ret;
105	case EXT2_IOC_GETRSVSZ:
106		if (test_opt(inode->i_sb, RESERVATION)
107			&& S_ISREG(inode->i_mode)
108			&& ei->i_block_alloc_info) {
109			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
110			return put_user(rsv_window_size, (int __user *)arg);
111		}
112		return -ENOTTY;
113	case EXT2_IOC_SETRSVSZ: {
114
115		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
116			return -ENOTTY;
117
118		if (!is_owner_or_cap(inode))
119			return -EACCES;
120
121		if (get_user(rsv_window_size, (int __user *)arg))
122			return -EFAULT;
123
124		ret = mnt_want_write(filp->f_path.mnt);
125		if (ret)
126			return ret;
127
128		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
129			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
130
131		/*
132		 * need to allocate reservation structure for this inode
133		 * before set the window size
134		 */
135		mutex_lock(&ei->truncate_mutex);
136		if (!ei->i_block_alloc_info)
137			ext2_init_block_alloc_info(inode);
138
139		if (ei->i_block_alloc_info){
140			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
141			rsv->rsv_goal_size = rsv_window_size;
142		}
143		mutex_unlock(&ei->truncate_mutex);
144		mnt_drop_write(filp->f_path.mnt);
145		return 0;
146	}
147	default:
148		return -ENOTTY;
149	}
150}
151
152#ifdef CONFIG_COMPAT
153long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
154{
155	/* These are just misnamed, they actually get/put from/to user an int */
156	switch (cmd) {
157	case EXT2_IOC32_GETFLAGS:
158		cmd = EXT2_IOC_GETFLAGS;
159		break;
160	case EXT2_IOC32_SETFLAGS:
161		cmd = EXT2_IOC_SETFLAGS;
162		break;
163	case EXT2_IOC32_GETVERSION:
164		cmd = EXT2_IOC_GETVERSION;
165		break;
166	case EXT2_IOC32_SETVERSION:
167		cmd = EXT2_IOC_SETVERSION;
168		break;
169	default:
170		return -ENOIOCTLCMD;
171	}
172	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
173}
174#endif
175