1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
7  *
8  * The original JFFS, from which the design for JFFS2 was derived,
9  * was designed and implemented by Axis Communications AB.
10  *
11  * The contents of this file are subject to the Red Hat eCos Public
12  * License Version 1.1 (the "Licence"); you may not use this file
13  * except in compliance with the Licence.  You may obtain a copy of
14  * the Licence at http://www.redhat.com/
15  *
16  * Software distributed under the Licence is distributed on an "AS IS"
17  * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
18  * See the Licence for the specific language governing rights and
19  * limitations under the Licence.
20  *
21  * The Original Code is JFFS2 - Journalling Flash File System, version 2
22  *
23  * Alternatively, the contents of this file may be used under the
24  * terms of the GNU General Public License version 2 (the "GPL"), in
25  * which case the provisions of the GPL are applicable instead of the
26  * above.  If you wish to allow the use of your version of this file
27  * only under the terms of the GPL and not to allow others to use your
28  * version of this file under the RHEPL, indicate your decision by
29  * deleting the provisions above and replace them with the notice and
30  * other provisions required by the GPL.  If you do not delete the
31  * provisions above, a recipient may use your version of this file
32  * under either the RHEPL or the GPL.
33  *
34  * $Id: super.c,v 1.48.2.3 2002/10/11 09:04:44 dwmw2 Exp $
35  *
36  */
37 
38 #include <linux/config.h>
39 #include <linux/kernel.h>
40 #include <linux/module.h>
41 #include <linux/version.h>
42 #include <linux/slab.h>
43 #include <linux/init.h>
44 #include <linux/list.h>
45 #include <linux/fs.h>
46 #include <linux/jffs2.h>
47 #include <linux/pagemap.h>
48 #include <linux/mtd/mtd.h>
49 #include <linux/interrupt.h>
50 #include "nodelist.h"
51 
52 #ifndef MTD_BLOCK_MAJOR
53 #define MTD_BLOCK_MAJOR 31
54 #endif
55 
56 extern void jffs2_read_inode (struct inode *);
57 void jffs2_put_super (struct super_block *);
58 void jffs2_write_super (struct super_block *);
59 static int jffs2_statfs (struct super_block *, struct statfs *);
60 int jffs2_remount_fs (struct super_block *, int *, char *);
61 extern void jffs2_clear_inode (struct inode *);
62 
63 static struct super_operations jffs2_super_operations =
64 {
65 	read_inode:	jffs2_read_inode,
66 //	delete_inode:	jffs2_delete_inode,
67 	put_super:	jffs2_put_super,
68 	write_super:	jffs2_write_super,
69 	statfs:		jffs2_statfs,
70 	remount_fs:	jffs2_remount_fs,
71 	clear_inode:	jffs2_clear_inode
72 };
73 
jffs2_statfs(struct super_block * sb,struct statfs * buf)74 static int jffs2_statfs(struct super_block *sb, struct statfs *buf)
75 {
76 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
77 	unsigned long avail;
78 
79 	buf->f_type = JFFS2_SUPER_MAGIC;
80 	buf->f_bsize = 1 << PAGE_SHIFT;
81 	buf->f_blocks = c->flash_size >> PAGE_SHIFT;
82 	buf->f_files = 0;
83 	buf->f_ffree = 0;
84 	buf->f_namelen = JFFS2_MAX_NAME_LEN;
85 
86 	spin_lock_bh(&c->erase_completion_lock);
87 
88 	avail = c->dirty_size + c->free_size;
89 	if (avail > c->sector_size * JFFS2_RESERVED_BLOCKS_WRITE)
90 		avail -= c->sector_size * JFFS2_RESERVED_BLOCKS_WRITE;
91 	else
92 		avail = 0;
93 
94 	buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
95 
96 #if CONFIG_JFFS2_FS_DEBUG > 0
97 	printk(KERN_DEBUG "STATFS:\n");
98 	printk(KERN_DEBUG "flash_size: %08x\n", c->flash_size);
99 	printk(KERN_DEBUG "used_size: %08x\n", c->used_size);
100 	printk(KERN_DEBUG "dirty_size: %08x\n", c->dirty_size);
101 	printk(KERN_DEBUG "free_size: %08x\n", c->free_size);
102 	printk(KERN_DEBUG "erasing_size: %08x\n", c->erasing_size);
103 	printk(KERN_DEBUG "bad_size: %08x\n", c->bad_size);
104 	printk(KERN_DEBUG "sector_size: %08x\n", c->sector_size);
105 
106 	if (c->nextblock) {
107 		printk(KERN_DEBUG "nextblock: 0x%08x\n", c->nextblock->offset);
108 	} else {
109 		printk(KERN_DEBUG "nextblock: NULL\n");
110 	}
111 	if (c->gcblock) {
112 		printk(KERN_DEBUG "gcblock: 0x%08x\n", c->gcblock->offset);
113 	} else {
114 		printk(KERN_DEBUG "gcblock: NULL\n");
115 	}
116 	if (list_empty(&c->clean_list)) {
117 		printk(KERN_DEBUG "clean_list: empty\n");
118 	} else {
119 		struct list_head *this;
120 
121 		list_for_each(this, &c->clean_list) {
122 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
123 			printk(KERN_DEBUG "clean_list: %08x\n", jeb->offset);
124 		}
125 	}
126 	if (list_empty(&c->dirty_list)) {
127 		printk(KERN_DEBUG "dirty_list: empty\n");
128 	} else {
129 		struct list_head *this;
130 
131 		list_for_each(this, &c->dirty_list) {
132 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
133 			printk(KERN_DEBUG "dirty_list: %08x\n", jeb->offset);
134 		}
135 	}
136 	if (list_empty(&c->erasing_list)) {
137 		printk(KERN_DEBUG "erasing_list: empty\n");
138 	} else {
139 		struct list_head *this;
140 
141 		list_for_each(this, &c->erasing_list) {
142 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
143 			printk(KERN_DEBUG "erasing_list: %08x\n", jeb->offset);
144 		}
145 	}
146 	if (list_empty(&c->erase_pending_list)) {
147 		printk(KERN_DEBUG "erase_pending_list: empty\n");
148 	} else {
149 		struct list_head *this;
150 
151 		list_for_each(this, &c->erase_pending_list) {
152 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
153 			printk(KERN_DEBUG "erase_pending_list: %08x\n", jeb->offset);
154 		}
155 	}
156 	if (list_empty(&c->free_list)) {
157 		printk(KERN_DEBUG "free_list: empty\n");
158 	} else {
159 		struct list_head *this;
160 
161 		list_for_each(this, &c->free_list) {
162 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
163 			printk(KERN_DEBUG "free_list: %08x\n", jeb->offset);
164 		}
165 	}
166 	if (list_empty(&c->bad_list)) {
167 		printk(KERN_DEBUG "bad_list: empty\n");
168 	} else {
169 		struct list_head *this;
170 
171 		list_for_each(this, &c->bad_list) {
172 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
173 			printk(KERN_DEBUG "bad_list: %08x\n", jeb->offset);
174 		}
175 	}
176 	if (list_empty(&c->bad_used_list)) {
177 		printk(KERN_DEBUG "bad_used_list: empty\n");
178 	} else {
179 		struct list_head *this;
180 
181 		list_for_each(this, &c->bad_used_list) {
182 			struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
183 			printk(KERN_DEBUG "bad_used_list: %08x\n", jeb->offset);
184 		}
185 	}
186 #endif /* CONFIG_JFFS2_FS_DEBUG */
187 
188 	spin_unlock_bh(&c->erase_completion_lock);
189 
190 
191 	return 0;
192 }
193 
jffs2_read_super(struct super_block * sb,void * data,int silent)194 static struct super_block *jffs2_read_super(struct super_block *sb, void *data, int silent)
195 {
196 	struct jffs2_sb_info *c;
197 	struct inode *root_i;
198 	int i;
199 
200 	D1(printk(KERN_DEBUG "jffs2: read_super for device %s\n", kdevname(sb->s_dev)));
201 
202 	if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR) {
203 		if (!silent)
204 			printk(KERN_DEBUG "jffs2: attempt to mount non-MTD device %s\n", kdevname(sb->s_dev));
205 		return NULL;
206 	}
207 
208 	c = JFFS2_SB_INFO(sb);
209 	memset(c, 0, sizeof(*c));
210 
211 	c->mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
212 	if (!c->mtd) {
213 		D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", MINOR(sb->s_dev)));
214 		return NULL;
215 	}
216 	c->sector_size = c->mtd->erasesize;
217 	c->free_size = c->flash_size = c->mtd->size;
218 	c->nr_blocks = c->mtd->size / c->mtd->erasesize;
219 	c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL);
220 	if (!c->blocks)
221 		goto out_mtd;
222 	for (i=0; i<c->nr_blocks; i++) {
223 		INIT_LIST_HEAD(&c->blocks[i].list);
224 		c->blocks[i].offset = i * c->sector_size;
225 		c->blocks[i].free_size = c->sector_size;
226 		c->blocks[i].dirty_size = 0;
227 		c->blocks[i].used_size = 0;
228 		c->blocks[i].first_node = NULL;
229 		c->blocks[i].last_node = NULL;
230 	}
231 
232 	spin_lock_init(&c->nodelist_lock);
233 	init_MUTEX(&c->alloc_sem);
234 	init_waitqueue_head(&c->erase_wait);
235 	spin_lock_init(&c->erase_completion_lock);
236 	spin_lock_init(&c->inocache_lock);
237 
238 	INIT_LIST_HEAD(&c->clean_list);
239 	INIT_LIST_HEAD(&c->dirty_list);
240 	INIT_LIST_HEAD(&c->erasing_list);
241 	INIT_LIST_HEAD(&c->erase_pending_list);
242 	INIT_LIST_HEAD(&c->erase_complete_list);
243 	INIT_LIST_HEAD(&c->free_list);
244 	INIT_LIST_HEAD(&c->bad_list);
245 	INIT_LIST_HEAD(&c->bad_used_list);
246 	c->highest_ino = 1;
247 
248 	if (jffs2_build_filesystem(c)) {
249 		D1(printk(KERN_DEBUG "build_fs failed\n"));
250 		goto out_nodes;
251 	}
252 
253 	sb->s_op = &jffs2_super_operations;
254 
255 	D1(printk(KERN_DEBUG "jffs2_read_super(): Getting root inode\n"));
256 	root_i = iget(sb, 1);
257 	if (is_bad_inode(root_i)) {
258 		D1(printk(KERN_WARNING "get root inode failed\n"));
259 		goto out_nodes;
260 	}
261 
262 	D1(printk(KERN_DEBUG "jffs2_read_super(): d_alloc_root()\n"));
263 	sb->s_root = d_alloc_root(root_i);
264 	if (!sb->s_root)
265 		goto out_root_i;
266 
267 #if LINUX_VERSION_CODE >= 0x20403
268 	sb->s_maxbytes = 0xFFFFFFFF;
269 #endif
270 	sb->s_blocksize = PAGE_CACHE_SIZE;
271 	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
272 	sb->s_magic = JFFS2_SUPER_MAGIC;
273 	if (!(sb->s_flags & MS_RDONLY))
274 		jffs2_start_garbage_collect_thread(c);
275 	return sb;
276 
277  out_root_i:
278 	iput(root_i);
279  out_nodes:
280 	jffs2_free_ino_caches(c);
281 	jffs2_free_raw_node_refs(c);
282 	kfree(c->blocks);
283  out_mtd:
284 	put_mtd_device(c->mtd);
285 	return NULL;
286 }
287 
jffs2_put_super(struct super_block * sb)288 void jffs2_put_super (struct super_block *sb)
289 {
290 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
291 
292 	D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
293 
294 	if (!(sb->s_flags & MS_RDONLY))
295 		jffs2_stop_garbage_collect_thread(c);
296 	jffs2_free_ino_caches(c);
297 	jffs2_free_raw_node_refs(c);
298 	kfree(c->blocks);
299 	if (c->mtd->sync)
300 		c->mtd->sync(c->mtd);
301 	put_mtd_device(c->mtd);
302 
303 	D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
304 }
305 
jffs2_remount_fs(struct super_block * sb,int * flags,char * data)306 int jffs2_remount_fs (struct super_block *sb, int *flags, char *data)
307 {
308 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
309 
310 	if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
311 		return -EROFS;
312 
313 	/* We stop if it was running, then restart if it needs to.
314 	   This also catches the case where it was stopped and this
315 	   is just a remount to restart it */
316 	if (!(sb->s_flags & MS_RDONLY))
317 		jffs2_stop_garbage_collect_thread(c);
318 
319 	if (!(*flags & MS_RDONLY))
320 		jffs2_start_garbage_collect_thread(c);
321 
322 	sb->s_flags = (sb->s_flags & ~MS_RDONLY)|(*flags & MS_RDONLY);
323 
324 	return 0;
325 }
326 
jffs2_write_super(struct super_block * sb)327 void jffs2_write_super (struct super_block *sb)
328 {
329 	struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
330 	sb->s_dirt = 0;
331 
332 	if (sb->s_flags & MS_RDONLY)
333 		return;
334 
335 	jffs2_garbage_collect_trigger(c);
336 	jffs2_erase_pending_blocks(c);
337 	jffs2_mark_erased_blocks(c);
338 }
339 
340 
341 static DECLARE_FSTYPE_DEV(jffs2_fs_type, "jffs2", jffs2_read_super);
342 
init_jffs2_fs(void)343 static int __init init_jffs2_fs(void)
344 {
345 	int ret;
346 
347 	printk(KERN_NOTICE "JFFS2 version 2.1. (C) 2001 Red Hat, Inc., designed by Axis Communications AB.\n");
348 
349 #ifdef JFFS2_OUT_OF_KERNEL
350 	/* sanity checks. Could we do these at compile time? */
351 	if (sizeof(struct jffs2_sb_info) > sizeof (((struct super_block *)NULL)->u)) {
352 		printk(KERN_ERR "JFFS2 error: struct jffs2_sb_info (%d bytes) doesn't fit in the super_block union (%d bytes)\n",
353 		       sizeof(struct jffs2_sb_info), sizeof (((struct super_block *)NULL)->u));
354 		return -EIO;
355 	}
356 
357 	if (sizeof(struct jffs2_inode_info) > sizeof (((struct inode *)NULL)->u)) {
358 		printk(KERN_ERR "JFFS2 error: struct jffs2_inode_info (%d bytes) doesn't fit in the inode union (%d bytes)\n",
359 		       sizeof(struct jffs2_inode_info), sizeof (((struct inode *)NULL)->u));
360 		return -EIO;
361 	}
362 #endif
363 
364 	ret = jffs2_zlib_init();
365 	if (ret) {
366 		printk(KERN_ERR "JFFS2 error: Failed to initialise zlib workspaces\n");
367 		goto out;
368 	}
369 	ret = jffs2_create_slab_caches();
370 	if (ret) {
371 		printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
372 		goto out_zlib;
373 	}
374 	ret = register_filesystem(&jffs2_fs_type);
375 	if (ret) {
376 		printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
377 		goto out_slab;
378 	}
379 	return 0;
380 
381  out_slab:
382 	jffs2_destroy_slab_caches();
383  out_zlib:
384 	jffs2_zlib_exit();
385  out:
386 	return ret;
387 }
388 
exit_jffs2_fs(void)389 static void __exit exit_jffs2_fs(void)
390 {
391 	jffs2_destroy_slab_caches();
392 	jffs2_zlib_exit();
393 	unregister_filesystem(&jffs2_fs_type);
394 }
395 
396 module_init(init_jffs2_fs);
397 module_exit(exit_jffs2_fs);
398 
399 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
400 MODULE_AUTHOR("Red Hat, Inc.");
401 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
402 		       // the sake of this tag. It's Free Software.
403