xref: /openbmc/linux/fs/reiserfs/ioctl.c (revision b6dcefde)
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/mount.h>
8 #include <linux/reiserfs_fs.h>
9 #include <linux/time.h>
10 #include <asm/uaccess.h>
11 #include <linux/pagemap.h>
12 #include <linux/smp_lock.h>
13 #include <linux/compat.h>
14 
15 /*
16  * reiserfs_ioctl - handler for ioctl for inode
17  * supported commands:
18  *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
19  *                           and prevent packing file (argument arg has to be non-zero)
20  *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
21  *  3) That's all for a while ...
22  */
23 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
24 {
25 	struct inode *inode = filp->f_path.dentry->d_inode;
26 	unsigned int flags;
27 	int err = 0;
28 
29 	reiserfs_write_lock(inode->i_sb);
30 
31 	switch (cmd) {
32 	case REISERFS_IOC_UNPACK:
33 		if (S_ISREG(inode->i_mode)) {
34 			if (arg)
35 				err = reiserfs_unpack(inode, filp);
36 		} else
37 			err = -ENOTTY;
38 		break;
39 		/*
40 		 * following two cases are taken from fs/ext2/ioctl.c by Remy
41 		 * Card (card@masi.ibp.fr)
42 		 */
43 	case REISERFS_IOC_GETFLAGS:
44 		if (!reiserfs_attrs(inode->i_sb)) {
45 			err = -ENOTTY;
46 			break;
47 		}
48 
49 		flags = REISERFS_I(inode)->i_attrs;
50 		i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
51 		err = put_user(flags, (int __user *)arg);
52 		break;
53 	case REISERFS_IOC_SETFLAGS:{
54 			if (!reiserfs_attrs(inode->i_sb)) {
55 				err = -ENOTTY;
56 				break;
57 			}
58 
59 			err = mnt_want_write(filp->f_path.mnt);
60 			if (err)
61 				break;
62 
63 			if (!is_owner_or_cap(inode)) {
64 				err = -EPERM;
65 				goto setflags_out;
66 			}
67 			if (get_user(flags, (int __user *)arg)) {
68 				err = -EFAULT;
69 				goto setflags_out;
70 			}
71 			/*
72 			 * Is it quota file? Do not allow user to mess with it
73 			 */
74 			if (IS_NOQUOTA(inode)) {
75 				err = -EPERM;
76 				goto setflags_out;
77 			}
78 			if (((flags ^ REISERFS_I(inode)->
79 			      i_attrs) & (REISERFS_IMMUTABLE_FL |
80 					  REISERFS_APPEND_FL))
81 			    && !capable(CAP_LINUX_IMMUTABLE)) {
82 				err = -EPERM;
83 				goto setflags_out;
84 			}
85 			if ((flags & REISERFS_NOTAIL_FL) &&
86 			    S_ISREG(inode->i_mode)) {
87 				int result;
88 
89 				result = reiserfs_unpack(inode, filp);
90 				if (result) {
91 					err = result;
92 					goto setflags_out;
93 				}
94 			}
95 			sd_attrs_to_i_attrs(flags, inode);
96 			REISERFS_I(inode)->i_attrs = flags;
97 			inode->i_ctime = CURRENT_TIME_SEC;
98 			mark_inode_dirty(inode);
99 setflags_out:
100 			mnt_drop_write(filp->f_path.mnt);
101 			break;
102 		}
103 	case REISERFS_IOC_GETVERSION:
104 		err = put_user(inode->i_generation, (int __user *)arg);
105 		break;
106 	case REISERFS_IOC_SETVERSION:
107 		if (!is_owner_or_cap(inode)) {
108 			err = -EPERM;
109 			break;
110 		}
111 		err = mnt_want_write(filp->f_path.mnt);
112 		if (err)
113 			break;
114 		if (get_user(inode->i_generation, (int __user *)arg)) {
115 			err = -EFAULT;
116 			goto setversion_out;
117 		}
118 		inode->i_ctime = CURRENT_TIME_SEC;
119 		mark_inode_dirty(inode);
120 setversion_out:
121 		mnt_drop_write(filp->f_path.mnt);
122 		break;
123 	default:
124 		err = -ENOTTY;
125 	}
126 
127 	reiserfs_write_unlock(inode->i_sb);
128 
129 	return err;
130 }
131 
132 #ifdef CONFIG_COMPAT
133 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
134 				unsigned long arg)
135 {
136 	/* These are just misnamed, they actually get/put from/to user an int */
137 	switch (cmd) {
138 	case REISERFS_IOC32_UNPACK:
139 		cmd = REISERFS_IOC_UNPACK;
140 		break;
141 	case REISERFS_IOC32_GETFLAGS:
142 		cmd = REISERFS_IOC_GETFLAGS;
143 		break;
144 	case REISERFS_IOC32_SETFLAGS:
145 		cmd = REISERFS_IOC_SETFLAGS;
146 		break;
147 	case REISERFS_IOC32_GETVERSION:
148 		cmd = REISERFS_IOC_GETVERSION;
149 		break;
150 	case REISERFS_IOC32_SETVERSION:
151 		cmd = REISERFS_IOC_SETVERSION;
152 		break;
153 	default:
154 		return -ENOIOCTLCMD;
155 	}
156 
157 	return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
158 }
159 #endif
160 
161 int reiserfs_commit_write(struct file *f, struct page *page,
162 			  unsigned from, unsigned to);
163 int reiserfs_prepare_write(struct file *f, struct page *page,
164 			   unsigned from, unsigned to);
165 /*
166 ** reiserfs_unpack
167 ** Function try to convert tail from direct item into indirect.
168 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
169 */
170 int reiserfs_unpack(struct inode *inode, struct file *filp)
171 {
172 	int retval = 0;
173 	int index;
174 	struct page *page;
175 	struct address_space *mapping;
176 	unsigned long write_from;
177 	unsigned long blocksize = inode->i_sb->s_blocksize;
178 
179 	if (inode->i_size == 0) {
180 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
181 		return 0;
182 	}
183 	/* ioctl already done */
184 	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
185 		return 0;
186 	}
187 
188 	/* we need to make sure nobody is changing the file size beneath
189 	 ** us
190 	 */
191 	mutex_lock(&inode->i_mutex);
192 	reiserfs_write_lock(inode->i_sb);
193 
194 	write_from = inode->i_size & (blocksize - 1);
195 	/* if we are on a block boundary, we are already unpacked.  */
196 	if (write_from == 0) {
197 		REISERFS_I(inode)->i_flags |= i_nopack_mask;
198 		goto out;
199 	}
200 
201 	/* we unpack by finding the page with the tail, and calling
202 	 ** reiserfs_prepare_write on that page.  This will force a
203 	 ** reiserfs_get_block to unpack the tail for us.
204 	 */
205 	index = inode->i_size >> PAGE_CACHE_SHIFT;
206 	mapping = inode->i_mapping;
207 	page = grab_cache_page(mapping, index);
208 	retval = -ENOMEM;
209 	if (!page) {
210 		goto out;
211 	}
212 	retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
213 	if (retval)
214 		goto out_unlock;
215 
216 	/* conversion can change page contents, must flush */
217 	flush_dcache_page(page);
218 	retval = reiserfs_commit_write(NULL, page, write_from, write_from);
219 	REISERFS_I(inode)->i_flags |= i_nopack_mask;
220 
221       out_unlock:
222 	unlock_page(page);
223 	page_cache_release(page);
224 
225       out:
226 	mutex_unlock(&inode->i_mutex);
227 	reiserfs_write_unlock(inode->i_sb);
228 	return retval;
229 }
230