1 /*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2001-2003 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 * $Id: super.c,v 1.104 2004/11/23 15:37:31 gleixner Exp $
11 *
12 */
13
14 #include <linux/config.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/init.h>
19 #include <linux/list.h>
20 #include <linux/fs.h>
21 #include <linux/mount.h>
22 #include <linux/jffs2.h>
23 #include <linux/pagemap.h>
24 #include <linux/mtd/mtd.h>
25 #include <linux/ctype.h>
26 #include <linux/namei.h>
27 #include "compr.h"
28 #include "nodelist.h"
29
30 static void jffs2_put_super(struct super_block *);
31
32 static kmem_cache_t *jffs2_inode_cachep;
33
34 static struct inode *jffs2_alloc_inode(struct super_block *sb)
35 {
36 struct jffs2_inode_info *ei;
37 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, SLAB_KERNEL);
38 if (!ei)
39 return NULL;
40 return &ei->vfs_inode;
41 }
42
43 static void jffs2_destroy_inode(struct inode *inode)
44 {
45 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
46 }
47
48 static void jffs2_i_init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
49 {
50 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;
51
52 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
53 SLAB_CTOR_CONSTRUCTOR) {
54 init_MUTEX_LOCKED(&ei->sem);
55 inode_init_once(&ei->vfs_inode);
56 }
57 }
58
59 static int jffs2_sync_fs(struct super_block *sb, int wait)
60 {
61 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
62
63 down(&c->alloc_sem);
64 jffs2_flush_wbuf_pad(c);
65 up(&c->alloc_sem);
66 return 0;
67 }
68
69 static struct super_operations jffs2_super_operations =
70 {
71 .alloc_inode = jffs2_alloc_inode,
72 .destroy_inode =jffs2_destroy_inode,
73 .read_inode = jffs2_read_inode,
74 .put_super = jffs2_put_super,
75 .write_super = jffs2_write_super,
76 .statfs = jffs2_statfs,
77 .remount_fs = jffs2_remount_fs,
78 .clear_inode = jffs2_clear_inode,
79 .dirty_inode = jffs2_dirty_inode,
80 .sync_fs = jffs2_sync_fs,
81 };
82
83 static int jffs2_sb_compare(struct super_block *sb, void *data)
84 {
85 struct jffs2_sb_info *p = data;
86 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
87
88 /* The superblocks are considered to be equivalent if the underlying MTD
89 device is the same one */
90 if (c->mtd == p->mtd) {
91 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name));
92 return 1;
93 } else {
94 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n",
95 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name));
96 return 0;
97 }
98 }
99
100 static int jffs2_sb_set(struct super_block *sb, void *data)
101 {
102 struct jffs2_sb_info *p = data;
103
104 /* For persistence of NFS exports etc. we use the same s_dev
105 each time we mount the device, don't just use an anonymous
106 device */
107 sb->s_fs_info = p;
108 p->os_priv = sb;
109 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index);
110
111 return 0;
112 }
113
114 static struct super_block *jffs2_get_sb_mtd(struct file_system_type *fs_type,
115 int flags, const char *dev_name,
116 void *data, struct mtd_info *mtd)
117 {
118 struct super_block *sb;
119 struct jffs2_sb_info *c;
120 int ret;
121
122 c = kmalloc(sizeof(*c), GFP_KERNEL);
123 if (!c)
124 return ERR_PTR(-ENOMEM);
125 memset(c, 0, sizeof(*c));
126 c->mtd = mtd;
127
128 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c);
129
130 if (IS_ERR(sb))
131 goto out_put;
132
133 if (sb->s_root) {
134 /* New mountpoint for JFFS2 which is already mounted */
135 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n",
136 mtd->index, mtd->name));
137 goto out_put;
138 }
139
140 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n",
141 mtd->index, mtd->name));
142
143 sb->s_op = &jffs2_super_operations;
144 sb->s_flags = flags | MS_NOATIME;
145
146 ret = jffs2_do_fill_super(sb, data, (flags&MS_VERBOSE)?1:0);
147
148 if (ret) {
149 /* Failure case... */
150 up_write(&sb->s_umount);
151 deactivate_super(sb);
152 return ERR_PTR(ret);
153 }
154
155 sb->s_flags |= MS_ACTIVE;
156 return sb;
157
158 out_put:
159 kfree(c);
160 put_mtd_device(mtd);
161
162 return sb;
163 }
164
165 static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
166 int flags, const char *dev_name,
167 void *data, int mtdnr)
168 {
169 struct mtd_info *mtd;
170
171 mtd = get_mtd_device(NULL, mtdnr);
172 if (!mtd) {
173 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
174 return ERR_PTR(-EINVAL);
175 }
176
177 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
178 }
179
180 static struct super_block *jffs2_get_sb(struct file_system_type *fs_type,
181 int flags, const char *dev_name,
182 void *data)
183 {
184 int err;
185 struct nameidata nd;
186 int mtdnr;
187
188 if (!dev_name)
189 return ERR_PTR(-EINVAL);
190
191 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));
192
193 /* The preferred way of mounting in future; especially when
194 CONFIG_BLK_DEV is implemented - we specify the underlying
195 MTD device by number or by name, so that we don't require
196 block device support to be present in the kernel. */
197
198 /* FIXME: How to do the root fs this way? */
199
200 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
201 /* Probably mounting without the blkdev crap */
202 if (dev_name[3] == ':') {
203 struct mtd_info *mtd;
204
205 /* Mount by MTD device name */
206 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
207 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
208 mtd = get_mtd_device(NULL, mtdnr);
209 if (mtd) {
210 if (!strcmp(mtd->name, dev_name+4))
211 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
212 put_mtd_device(mtd);
213 }
214 }
215 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
216 } else if (isdigit(dev_name[3])) {
217 /* Mount by MTD device number name */
218 char *endptr;
219
220 mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
221 if (!*endptr) {
222 /* It was a valid number */
223 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
224 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
225 }
226 }
227 }
228
229 /* Try the old way - the hack where we allowed users to mount
230 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */
231
232 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
233
234 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
235 err, nd.dentry->d_inode));
236
237 if (err)
238 return ERR_PTR(err);
239
240 err = -EINVAL;
241
242 if (!S_ISBLK(nd.dentry->d_inode->i_mode))
243 goto out;
244
245 if (nd.mnt->mnt_flags & MNT_NODEV) {
246 err = -EACCES;
247 goto out;
248 }
249
250 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
251 if (!(flags & MS_VERBOSE)) /* Yes I mean this. Strangely */
252 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
253 dev_name);
254 goto out;
255 }
256
257 mtdnr = iminor(nd.dentry->d_inode);
258 path_release(&nd);
259
260 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
261
262 out:
263 path_release(&nd);
264 return ERR_PTR(err);
265 }
266
267 static void jffs2_put_super (struct super_block *sb)
268 {
269 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
270
271 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
272
273 if (!(sb->s_flags & MS_RDONLY))
274 jffs2_stop_garbage_collect_thread(c);
275 down(&c->alloc_sem);
276 jffs2_flush_wbuf_pad(c);
277 up(&c->alloc_sem);
278 jffs2_free_ino_caches(c);
279 jffs2_free_raw_node_refs(c);
280 if (c->mtd->flags & MTD_NO_VIRTBLOCKS)
281 vfree(c->blocks);
282 else
283 kfree(c->blocks);
284 jffs2_flash_cleanup(c);
285 kfree(c->inocache_list);
286 if (c->mtd->sync)
287 c->mtd->sync(c->mtd);
288
289 D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
290 }
291
292 static void jffs2_kill_sb(struct super_block *sb)
293 {
294 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
295 generic_shutdown_super(sb);
296 put_mtd_device(c->mtd);
297 kfree(c);
298 }
299
300 static struct file_system_type jffs2_fs_type = {
301 .owner = THIS_MODULE,
302 .name = "jffs2",
303 .get_sb = jffs2_get_sb,
304 .kill_sb = jffs2_kill_sb,
305 };
306
307 static int __init init_jffs2_fs(void)
308 {
309 int ret;
310
311 printk(KERN_INFO "JFFS2 version 2.2."
312 #ifdef CONFIG_JFFS2_FS_NAND
313 " (NAND)"
314 #endif
315 " (C) 2001-2003 Red Hat, Inc.\n");
316
317 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
318 sizeof(struct jffs2_inode_info),
319 0, SLAB_RECLAIM_ACCOUNT,
320 jffs2_i_init_once, NULL);
321 if (!jffs2_inode_cachep) {
322 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
323 return -ENOMEM;
324 }
325 ret = jffs2_compressors_init();
326 if (ret) {
327 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
328 goto out;
329 }
330 ret = jffs2_create_slab_caches();
331 if (ret) {
332 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
333 goto out_compressors;
334 }
335 ret = register_filesystem(&jffs2_fs_type);
336 if (ret) {
337 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
338 goto out_slab;
339 }
340 return 0;
341
342 out_slab:
343 jffs2_destroy_slab_caches();
344 out_compressors:
345 jffs2_compressors_exit();
346 out:
347 kmem_cache_destroy(jffs2_inode_cachep);
348 return ret;
349 }
350
351 static void __exit exit_jffs2_fs(void)
352 {
353 unregister_filesystem(&jffs2_fs_type);
354 jffs2_destroy_slab_caches();
355 jffs2_compressors_exit();
356 kmem_cache_destroy(jffs2_inode_cachep);
357 }
358
359 module_init(init_jffs2_fs);
360 module_exit(exit_jffs2_fs);
361
362 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
363 MODULE_AUTHOR("Red Hat, Inc.");
364 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
365 // the sake of this tag. It's Free Software.
366
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