xref: /minix3/sys/fs/v7fs/v7fs_file_util.c (revision ebfedea0ce5bbe81e252ddf32d732e40fb633fae)
1 /*	$NetBSD: v7fs_file_util.c,v 1.4 2011/07/30 03:52:04 uch Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by UCHIYAMA Yasushi.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: v7fs_file_util.c,v 1.4 2011/07/30 03:52:04 uch Exp $");
38 #ifdef _KERNEL
39 #include <sys/systm.h>
40 #include <sys/param.h>
41 #else
42 #include <stdio.h>
43 #include <string.h>
44 #include <errno.h>
45 #endif
46 
47 #include "v7fs.h"
48 #include "v7fs_impl.h"
49 #include "v7fs_endian.h"
50 #include "v7fs_inode.h"
51 #include "v7fs_dirent.h"
52 #include "v7fs_file.h"
53 #include "v7fs_datablock.h"
54 
55 #ifdef V7FS_FILE_DEBUG
56 #define	DPRINTF(fmt, args...)	printf("%s: " fmt, __func__, ##args)
57 #else
58 #define	DPRINTF(fmt, args...)	((void)0)
59 #endif
60 
61 static int replace_subr(struct v7fs_self *, void *, v7fs_daddr_t, size_t);
62 static int lookup_by_number_subr(struct v7fs_self *, void *, v7fs_daddr_t,
63     size_t);
64 static int can_dirmove(struct v7fs_self *, v7fs_ino_t, v7fs_ino_t);
65 static int lookup_parent_from_dir_subr(struct v7fs_self *, void *,
66     v7fs_daddr_t, size_t);
67 
68 int
69 v7fs_file_link(struct v7fs_self *fs, struct v7fs_inode *parent_dir,
70     struct v7fs_inode *p, const char *name)
71 {
72 	int error = 0;
73 
74 	DPRINTF("%d %d %s\n", parent_dir->inode_number, p->inode_number, name);
75 	if ((error = v7fs_directory_add_entry(fs, parent_dir, p->inode_number,
76 	    name))) {
77 		DPRINTF("can't add entry");
78 		return error;
79 	}
80 	p->nlink++;
81 	v7fs_inode_writeback(fs, p);
82 
83 	return 0;
84 }
85 
86 int
87 v7fs_file_symlink(struct v7fs_self *fs, struct v7fs_inode *p,
88     const char *target)
89 {
90 	int error;
91 	size_t len = strlen(target) + 1;
92 
93 	if (len > V7FSBSD_MAXSYMLINKLEN) {/* limited target 512byte pathname */
94 		DPRINTF("too long pathname.");
95 		return ENAMETOOLONG;
96 	}
97 
98 	if ((error = v7fs_datablock_expand(fs, p, len))) {
99 		return error;
100 	}
101 
102 	v7fs_daddr_t blk = p->addr[0];	/* 1block only.  */
103 	void *buf;
104 	if (!(buf = scratch_read(fs, blk))) {
105 		return EIO;
106 	}
107 
108 	strncpy(buf, target, V7FS_BSIZE);
109 	if (!fs->io.write(fs->io.cookie, buf, blk)) {
110 		scratch_free(fs, buf);
111 		return EIO;
112 	}
113 	scratch_free(fs, buf);
114 	v7fs_inode_writeback(fs, p);
115 
116 	return 0;
117 }
118 
119 int
120 v7fs_file_rename(struct v7fs_self *fs, struct v7fs_inode *parent_from,
121     const char *from, struct v7fs_inode *parent_to, const char *to)
122 {
123 	v7fs_ino_t from_ino, to_ino;
124 	struct v7fs_inode inode;
125 	int error;
126 	bool dir_move;
127 
128 	/* Check source file */
129 	if ((error = v7fs_file_lookup_by_name(fs, parent_from, from,
130 	    &from_ino))) {
131 		DPRINTF("%s don't exists\n", from);
132 		return error;
133 	}
134 	v7fs_inode_load(fs, &inode, from_ino);
135 	dir_move = v7fs_inode_isdir(&inode);
136 
137 	/* Check target file */
138 	error = v7fs_file_lookup_by_name(fs, parent_to, to, &to_ino);
139 	if (error == 0) {	/* found */
140 		DPRINTF("%s already exists\n", to);
141 		if ((error = v7fs_file_deallocate(fs, parent_to, to))) {
142 			DPRINTF("%s can't remove %d\n", to, error);
143 			return error;
144 		}
145 	} else if (error != ENOENT) {
146 		DPRINTF("error=%d\n", error);
147 		return error;
148 	}
149 	/* Check directory hierarchy. t_vnops rename_dir(5) */
150 	if (dir_move && (error = can_dirmove(fs, from_ino,
151 	    parent_to->inode_number))) {
152 		DPRINTF("dst '%s' is child dir of '%s'. error=%d\n", to, from,
153 		    error);
154 		return error;
155 	}
156 
157 	if ((error = v7fs_directory_add_entry(fs, parent_to, from_ino, to))) {
158 		DPRINTF("can't add entry");
159 		return error;
160 	}
161 
162 	if ((error = v7fs_directory_remove_entry(fs, parent_from, from))) {
163 		DPRINTF("can't remove entry");
164 		return error;
165 	}
166 
167 	if (dir_move && (parent_from != parent_to)) {
168 		/* If directory move, update ".." */
169 		if ((error = v7fs_directory_replace_entry(fs, &inode, "..",
170 			    parent_to->inode_number))) {
171 			DPRINTF("can't replace parent dir");
172 			return error;
173 		}
174 		v7fs_inode_writeback(fs, &inode);
175 	}
176 
177 	return 0;
178 }
179 
180 
181 int
182 v7fs_directory_replace_entry(struct v7fs_self *fs,  struct v7fs_inode *self_dir,
183     const char *name, v7fs_ino_t ino)
184 {
185 	int error;
186 
187 	/* Search entry that replaced. replace it to new inode number. */
188 	struct v7fs_lookup_arg lookup_arg = { .name = name,
189 					      .inode_number = ino };
190 	if ((error = v7fs_datablock_foreach(fs, self_dir, replace_subr,
191 	    &lookup_arg)) != V7FS_ITERATOR_BREAK)
192 		return ENOENT;
193 
194 	return 0;
195 }
196 
197 static int
198 replace_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk, size_t sz)
199 {
200 	struct v7fs_lookup_arg *p = (struct v7fs_lookup_arg *)ctx;
201 	struct v7fs_dirent *dir;
202 	void *buf;
203 	size_t i, n;
204 	int ret = 0;
205 
206 	DPRINTF("match start blk=%x\n", blk);
207 	if (!(buf = scratch_read(fs, blk)))
208 		return EIO;
209 
210 	dir = (struct v7fs_dirent *)buf;
211 	n = sz / sizeof(*dir);
212 
213 	for (i = 0; i < n; i++, dir++) { /*disk endian */
214 		if (strncmp(p->name, (const char *)dir->name, V7FS_NAME_MAX)
215 		    == 0) {
216 			/* Replace inode# */
217 			dir->inode_number = V7FS_VAL16(fs, p->inode_number);
218 			/* Write back. */
219 			if (!fs->io.write(fs->io.cookie, buf, blk))
220 				ret = EIO;
221 			else
222 				ret = V7FS_ITERATOR_BREAK;
223 			break;
224 		}
225 	}
226 	scratch_free(fs, buf);
227 
228 	return ret;
229 }
230 
231 bool
232 v7fs_file_lookup_by_number(struct v7fs_self *fs, struct v7fs_inode *parent_dir,
233     v7fs_ino_t ino, char *buf)
234 {
235 	int ret;
236 
237 	ret = v7fs_datablock_foreach(fs, parent_dir, lookup_by_number_subr,
238 	    &(struct v7fs_lookup_arg){ .inode_number = ino, .buf = buf });
239 
240 	return ret == V7FS_ITERATOR_BREAK;
241 }
242 
243 static int
244 lookup_by_number_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk,
245     size_t sz)
246 {
247 	struct v7fs_lookup_arg *p = (struct v7fs_lookup_arg *)ctx;
248 	struct v7fs_dirent *dir;
249 	void *buf;
250 	size_t i, n;
251 	int ret = 0;
252 
253 	if (!(buf = scratch_read(fs, blk)))
254 		return EIO;
255 
256 	dir = (struct v7fs_dirent *)buf;
257 	n = sz / sizeof(*dir);
258 	v7fs_dirent_endian_convert(fs, dir, n);
259 
260 	for (i = 0; i < n; i++, dir++) {
261 		if (dir->inode_number == p->inode_number) {
262 			if (p->buf)
263 				v7fs_dirent_filename(p->buf, dir->name);
264 			ret = V7FS_ITERATOR_BREAK;
265 			break;
266 		}
267 	}
268 	scratch_free(fs, buf);
269 
270 	return ret;
271 }
272 
273 struct lookup_parent_arg {
274 	v7fs_ino_t parent_ino;
275 };
276 
277 static int
278 can_dirmove(struct v7fs_self *fs, v7fs_ino_t from_ino, v7fs_ino_t to_ino)
279 {
280 	struct v7fs_inode inode;
281 	v7fs_ino_t parent;
282 	int error;
283 
284 	/* Start dir. */
285 	if ((error = v7fs_inode_load(fs, &inode, to_ino)))
286 		return error;
287 
288 	if (!v7fs_inode_isdir(&inode))
289 		return ENOTDIR;
290 
291 	/* Lookup the parent. */
292 	do {
293 		struct lookup_parent_arg arg;
294 		/* Search parent dir */
295 		arg.parent_ino = 0;
296 		v7fs_datablock_foreach(fs, &inode, lookup_parent_from_dir_subr,
297 		    &arg);
298 		if ((parent = arg.parent_ino) == 0) {
299 			DPRINTF("***parent missing\n");
300 			return ENOENT;
301 		}
302 		/* Load parent dir */
303 		if ((error = v7fs_inode_load(fs, &inode, parent)))
304 			return error;
305 		if (parent == from_ino) {
306 			DPRINTF("#%d is child dir of #%d\n", to_ino, from_ino);
307 			return EINVAL;
308 		}
309 	} while (parent != V7FS_ROOT_INODE);
310 
311 	return 0;
312 }
313 
314 static int
315 lookup_parent_from_dir_subr(struct v7fs_self *fs, void *ctx, v7fs_daddr_t blk,
316     size_t sz)
317 {
318 	struct lookup_parent_arg *arg = (struct lookup_parent_arg *)ctx;
319 	char name[V7FS_NAME_MAX + 1];
320 	void *buf;
321 	int ret = 0;
322 
323 	if (!(buf = scratch_read(fs, blk)))
324 		return 0;
325 	struct v7fs_dirent *dir = (struct v7fs_dirent *)buf;
326 	size_t i, n = sz / sizeof(*dir);
327 	if (!v7fs_dirent_endian_convert(fs, dir, n)) {
328 		scratch_free(fs, buf);
329 		return V7FS_ITERATOR_ERROR;
330 	}
331 
332 	for (i = 0; i < n; i++, dir++) {
333 		v7fs_dirent_filename(name, dir->name);
334 		if (strncmp(dir->name, "..", V7FS_NAME_MAX) != 0)
335 			continue;
336 
337 		arg->parent_ino = dir->inode_number;
338 		ret = V7FS_ITERATOR_BREAK;
339 		break;
340 	}
341 
342 	scratch_free(fs, buf);
343 	return ret;
344 }
345