xref: /linux/fs/ext2/ioctl.c (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/ext2/ioctl.c
4  *
5  * Copyright (C) 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  */
10 
11 #include "ext2.h"
12 #include <linux/capability.h>
13 #include <linux/time.h>
14 #include <linux/sched.h>
15 #include <linux/compat.h>
16 #include <linux/mount.h>
17 #include <asm/current.h>
18 #include <linux/uaccess.h>
19 #include <linux/fileattr.h>
20 
ext2_fileattr_get(struct dentry * dentry,struct fileattr * fa)21 int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
22 {
23 	struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
24 
25 	fileattr_fill_flags(fa, ei->i_flags & EXT2_FL_USER_VISIBLE);
26 
27 	return 0;
28 }
29 
ext2_fileattr_set(struct mnt_idmap * idmap,struct dentry * dentry,struct fileattr * fa)30 int ext2_fileattr_set(struct mnt_idmap *idmap,
31 		      struct dentry *dentry, struct fileattr *fa)
32 {
33 	struct inode *inode = d_inode(dentry);
34 	struct ext2_inode_info *ei = EXT2_I(inode);
35 
36 	if (fileattr_has_fsx(fa))
37 		return -EOPNOTSUPP;
38 
39 	/* Is it quota file? Do not allow user to mess with it */
40 	if (IS_NOQUOTA(inode))
41 		return -EPERM;
42 
43 	ei->i_flags = (ei->i_flags & ~EXT2_FL_USER_MODIFIABLE) |
44 		(fa->flags & EXT2_FL_USER_MODIFIABLE);
45 
46 	ext2_set_inode_flags(inode);
47 	inode_set_ctime_current(inode);
48 	mark_inode_dirty(inode);
49 
50 	return 0;
51 }
52 
53 
ext2_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)54 long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
55 {
56 	struct inode *inode = file_inode(filp);
57 	struct ext2_inode_info *ei = EXT2_I(inode);
58 	unsigned short rsv_window_size;
59 	int ret;
60 
61 	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
62 
63 	switch (cmd) {
64 	case EXT2_IOC_GETVERSION:
65 		return put_user(inode->i_generation, (int __user *) arg);
66 	case EXT2_IOC_SETVERSION: {
67 		__u32 generation;
68 
69 		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
70 			return -EPERM;
71 		ret = mnt_want_write_file(filp);
72 		if (ret)
73 			return ret;
74 		if (get_user(generation, (int __user *) arg)) {
75 			ret = -EFAULT;
76 			goto setversion_out;
77 		}
78 
79 		inode_lock(inode);
80 		inode_set_ctime_current(inode);
81 		inode->i_generation = generation;
82 		inode_unlock(inode);
83 
84 		mark_inode_dirty(inode);
85 setversion_out:
86 		mnt_drop_write_file(filp);
87 		return ret;
88 	}
89 	case EXT2_IOC_GETRSVSZ:
90 		if (test_opt(inode->i_sb, RESERVATION)
91 			&& S_ISREG(inode->i_mode)
92 			&& ei->i_block_alloc_info) {
93 			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
94 			return put_user(rsv_window_size, (int __user *)arg);
95 		}
96 		return -ENOTTY;
97 	case EXT2_IOC_SETRSVSZ: {
98 
99 		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
100 			return -ENOTTY;
101 
102 		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
103 			return -EACCES;
104 
105 		if (get_user(rsv_window_size, (int __user *)arg))
106 			return -EFAULT;
107 
108 		ret = mnt_want_write_file(filp);
109 		if (ret)
110 			return ret;
111 
112 		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
113 			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
114 
115 		/*
116 		 * need to allocate reservation structure for this inode
117 		 * before set the window size
118 		 */
119 		/*
120 		 * XXX What lock should protect the rsv_goal_size?
121 		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
122 		 */
123 		mutex_lock(&ei->truncate_mutex);
124 		if (!ei->i_block_alloc_info)
125 			ext2_init_block_alloc_info(inode);
126 
127 		if (ei->i_block_alloc_info){
128 			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
129 			rsv->rsv_goal_size = rsv_window_size;
130 		} else {
131 			ret = -ENOMEM;
132 		}
133 
134 		mutex_unlock(&ei->truncate_mutex);
135 		mnt_drop_write_file(filp);
136 		return ret;
137 	}
138 	default:
139 		return -ENOTTY;
140 	}
141 }
142 
143 #ifdef CONFIG_COMPAT
ext2_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)144 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
145 {
146 	/* These are just misnamed, they actually get/put from/to user an int */
147 	switch (cmd) {
148 	case EXT2_IOC32_GETVERSION:
149 		cmd = EXT2_IOC_GETVERSION;
150 		break;
151 	case EXT2_IOC32_SETVERSION:
152 		cmd = EXT2_IOC_SETVERSION;
153 		break;
154 	default:
155 		return -ENOIOCTLCMD;
156 	}
157 	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
158 }
159 #endif
160