xref: /openbmc/linux/fs/jfs/ioctl.c (revision 63dc02bd)
1 /*
2  * linux/fs/jfs/ioctl.c
3  *
4  * Copyright (C) 2006 Herbert Poetzl
5  * adapted from Remy Card's ext2/ioctl.c
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/ctype.h>
10 #include <linux/capability.h>
11 #include <linux/mount.h>
12 #include <linux/time.h>
13 #include <linux/sched.h>
14 #include <asm/current.h>
15 #include <asm/uaccess.h>
16 
17 #include "jfs_incore.h"
18 #include "jfs_dinode.h"
19 #include "jfs_inode.h"
20 
21 
22 static struct {
23 	long jfs_flag;
24 	long ext2_flag;
25 } jfs_map[] = {
26 	{JFS_NOATIME_FL,	FS_NOATIME_FL},
27 	{JFS_DIRSYNC_FL,	FS_DIRSYNC_FL},
28 	{JFS_SYNC_FL,		FS_SYNC_FL},
29 	{JFS_SECRM_FL,		FS_SECRM_FL},
30 	{JFS_UNRM_FL,		FS_UNRM_FL},
31 	{JFS_APPEND_FL,		FS_APPEND_FL},
32 	{JFS_IMMUTABLE_FL,	FS_IMMUTABLE_FL},
33 	{0, 0},
34 };
35 
36 static long jfs_map_ext2(unsigned long flags, int from)
37 {
38 	int index=0;
39 	long mapped=0;
40 
41 	while (jfs_map[index].jfs_flag) {
42 		if (from) {
43 			if (jfs_map[index].ext2_flag & flags)
44 				mapped |= jfs_map[index].jfs_flag;
45 		} else {
46 			if (jfs_map[index].jfs_flag & flags)
47 				mapped |= jfs_map[index].ext2_flag;
48 		}
49 		index++;
50 	}
51 	return mapped;
52 }
53 
54 
55 long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
56 {
57 	struct inode *inode = filp->f_dentry->d_inode;
58 	struct jfs_inode_info *jfs_inode = JFS_IP(inode);
59 	unsigned int flags;
60 
61 	switch (cmd) {
62 	case JFS_IOC_GETFLAGS:
63 		jfs_get_inode_flags(jfs_inode);
64 		flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
65 		flags = jfs_map_ext2(flags, 0);
66 		return put_user(flags, (int __user *) arg);
67 	case JFS_IOC_SETFLAGS: {
68 		unsigned int oldflags;
69 		int err;
70 
71 		err = mnt_want_write_file(filp);
72 		if (err)
73 			return err;
74 
75 		if (!inode_owner_or_capable(inode)) {
76 			err = -EACCES;
77 			goto setflags_out;
78 		}
79 		if (get_user(flags, (int __user *) arg)) {
80 			err = -EFAULT;
81 			goto setflags_out;
82 		}
83 
84 		flags = jfs_map_ext2(flags, 1);
85 		if (!S_ISDIR(inode->i_mode))
86 			flags &= ~JFS_DIRSYNC_FL;
87 
88 		/* Is it quota file? Do not allow user to mess with it */
89 		if (IS_NOQUOTA(inode)) {
90 			err = -EPERM;
91 			goto setflags_out;
92 		}
93 
94 		/* Lock against other parallel changes of flags */
95 		mutex_lock(&inode->i_mutex);
96 
97 		jfs_get_inode_flags(jfs_inode);
98 		oldflags = jfs_inode->mode2;
99 
100 		/*
101 		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
102 		 * the relevant capability.
103 		 */
104 		if ((oldflags & JFS_IMMUTABLE_FL) ||
105 			((flags ^ oldflags) &
106 			(JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
107 			if (!capable(CAP_LINUX_IMMUTABLE)) {
108 				mutex_unlock(&inode->i_mutex);
109 				err = -EPERM;
110 				goto setflags_out;
111 			}
112 		}
113 
114 		flags = flags & JFS_FL_USER_MODIFIABLE;
115 		flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
116 		jfs_inode->mode2 = flags;
117 
118 		jfs_set_inode_flags(inode);
119 		mutex_unlock(&inode->i_mutex);
120 		inode->i_ctime = CURRENT_TIME_SEC;
121 		mark_inode_dirty(inode);
122 setflags_out:
123 		mnt_drop_write_file(filp);
124 		return err;
125 	}
126 	default:
127 		return -ENOTTY;
128 	}
129 }
130 
131 #ifdef CONFIG_COMPAT
132 long jfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
133 {
134 	/* While these ioctl numbers defined with 'long' and have different
135 	 * numbers than the 64bit ABI,
136 	 * the actual implementation only deals with ints and is compatible.
137 	 */
138 	switch (cmd) {
139 	case JFS_IOC_GETFLAGS32:
140 		cmd = JFS_IOC_GETFLAGS;
141 		break;
142 	case JFS_IOC_SETFLAGS32:
143 		cmd = JFS_IOC_SETFLAGS;
144 		break;
145 	}
146 	return jfs_ioctl(filp, cmd, arg);
147 }
148 #endif
149