xref: /openbmc/linux/fs/reiserfs/ioctl.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4 
5 #include <linux/capability.h>
6 #include <linux/fs.h>
7 #include <linux/reiserfs_fs.h>
8 #include <linux/time.h>
9 #include <asm/uaccess.h>
10 #include <linux/pagemap.h>
11 #include <linux/smp_lock.h>
12 #include <linux/compat.h>
13 
14 static int reiserfs_unpack(struct inode *inode, struct file *filp);
15 
16 /*
17 ** reiserfs_ioctl - handler for ioctl for inode
18 ** supported commands:
19 **  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
20 **                           and prevent packing file (argument arg has to be non-zero)
21 **  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
22 **  3) That's all for a while ...
23 */
24 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
25 		   unsigned long arg)
26 {
27 	unsigned int flags;
28 
29 	switch (cmd) {
30 	case REISERFS_IOC_UNPACK:
31 		if (S_ISREG(inode->i_mode)) {
32 			if (arg)
33 				return reiserfs_unpack(inode, filp);
34 			else
35 				return 0;
36 		} else
37 			return -ENOTTY;
38 		/* following two cases are taken from fs/ext2/ioctl.c by Remy
39 		   Card (card@masi.ibp.fr) */
40 	case REISERFS_IOC_GETFLAGS:
41 		if (!reiserfs_attrs(inode->i_sb))
42 			return -ENOTTY;
43 
44 		flags = REISERFS_I(inode)->i_attrs;
45 		i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
46 		return put_user(flags, (int __user *)arg);
47 	case REISERFS_IOC_SETFLAGS:{
48 			if (!reiserfs_attrs(inode->i_sb))
49 				return -ENOTTY;
50 
51 			if (IS_RDONLY(inode))
52 				return -EROFS;
53 
54 			if ((current->fsuid != inode->i_uid)
55 			    && !capable(CAP_FOWNER))
56 				return -EPERM;
57 
58 			if (get_user(flags, (int __user *)arg))
59 				return -EFAULT;
60 
61 			if (((flags ^ REISERFS_I(inode)->
62 			      i_attrs) & (REISERFS_IMMUTABLE_FL |
63 					  REISERFS_APPEND_FL))
64 			    && !capable(CAP_LINUX_IMMUTABLE))
65 				return -EPERM;
66 
67 			if ((flags & REISERFS_NOTAIL_FL) &&
68 			    S_ISREG(inode->i_mode)) {
69 				int result;
70 
71 				result = reiserfs_unpack(inode, filp);
72 				if (result)
73 					return result;
74 			}
75 			sd_attrs_to_i_attrs(flags, inode);
76 			REISERFS_I(inode)->i_attrs = flags;
77 			inode->i_ctime = CURRENT_TIME_SEC;
78 			mark_inode_dirty(inode);
79 			return 0;
80 		}
81 	case REISERFS_IOC_GETVERSION:
82 		return put_user(inode->i_generation, (int __user *)arg);
83 	case REISERFS_IOC_SETVERSION:
84 		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
85 			return -EPERM;
86 		if (IS_RDONLY(inode))
87 			return -EROFS;
88 		if (get_user(inode->i_generation, (int __user *)arg))
89 			return -EFAULT;
90 		inode->i_ctime = CURRENT_TIME_SEC;
91 		mark_inode_dirty(inode);
92 		return 0;
93 	default:
94 		return -ENOTTY;
95 	}
96 }
97 
98 #ifdef CONFIG_COMPAT
99 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
100 				unsigned long arg)
101 {
102 	struct inode *inode = file->f_path.dentry->d_inode;
103 	int ret;
104 
105 	/* These are just misnamed, they actually get/put from/to user an int */
106 	switch (cmd) {
107 	case REISERFS_IOC32_UNPACK:
108 		cmd = REISERFS_IOC_UNPACK;
109 		break;
110 	case REISERFS_IOC32_GETFLAGS:
111 		cmd = REISERFS_IOC_GETFLAGS;
112 		break;
113 	case REISERFS_IOC32_SETFLAGS:
114 		cmd = REISERFS_IOC_SETFLAGS;
115 		break;
116 	case REISERFS_IOC32_GETVERSION:
117 		cmd = REISERFS_IOC_GETVERSION;
118 		break;
119 	case REISERFS_IOC32_SETVERSION:
120 		cmd = REISERFS_IOC_SETVERSION;
121 		break;
122 	default:
123 		return -ENOIOCTLCMD;
124 	}
125 	lock_kernel();
126 	ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
127 	unlock_kernel();
128 	return ret;
129 }
130 #endif
131 
132 /*
133 ** reiserfs_unpack
134 ** Function try to convert tail from direct item into indirect.
135 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
136 */
137 static int reiserfs_unpack(struct inode *inode, struct file *filp)
138 {
139 	int retval = 0;
140 	int index;
141 	struct page *page;
142 	struct address_space *mapping;
143 	unsigned long write_from;
144 	unsigned long blocksize = inode->i_sb->s_blocksize;
145 
146 	if (inode->i_size == 0) {
147 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
148 		return 0;
149 	}
150 	/* ioctl already done */
151 	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
152 		return 0;
153 	}
154 
155 	/* we need to make sure nobody is changing the file size beneath
156 	 ** us
157 	 */
158 	mutex_lock(&inode->i_mutex);
159 	reiserfs_write_lock(inode->i_sb);
160 
161 	write_from = inode->i_size & (blocksize - 1);
162 	/* if we are on a block boundary, we are already unpacked.  */
163 	if (write_from == 0) {
164 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
165 		goto out;
166 	}
167 
168 	/* we unpack by finding the page with the tail, and calling
169 	 ** reiserfs_prepare_write on that page.  This will force a
170 	 ** reiserfs_get_block to unpack the tail for us.
171 	 */
172 	index = inode->i_size >> PAGE_CACHE_SHIFT;
173 	mapping = inode->i_mapping;
174 	page = grab_cache_page(mapping, index);
175 	retval = -ENOMEM;
176 	if (!page) {
177 		goto out;
178 	}
179 	retval =
180 	    mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
181 	if (retval)
182 		goto out_unlock;
183 
184 	/* conversion can change page contents, must flush */
185 	flush_dcache_page(page);
186 	retval =
187 	    mapping->a_ops->commit_write(NULL, page, write_from, write_from);
188 	REISERFS_I(inode)->i_flags |= i_nopack_mask;
189 
190       out_unlock:
191 	unlock_page(page);
192 	page_cache_release(page);
193 
194       out:
195 	mutex_unlock(&inode->i_mutex);
196 	reiserfs_write_unlock(inode->i_sb);
197 	return retval;
198 }
199