[PATCH] cpuset memory spread: slab cache filesystems
[linux-2.6.git] / fs / jffs2 / super.c
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 1.110 2005/11/07 11:14:42 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(&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         /* Initialize JFFS2 superblock locks, the further initialization will be
144          * done later */
145         init_MUTEX(&c->alloc_sem);
146         init_MUTEX(&c->erase_free_sem);
147         init_waitqueue_head(&c->erase_wait);
148         init_waitqueue_head(&c->inocache_wq);
149         spin_lock_init(&c->erase_completion_lock);
150         spin_lock_init(&c->inocache_lock);
151
152         sb->s_op = &jffs2_super_operations;
153         sb->s_flags = flags | MS_NOATIME;
154
155         ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
156
157         if (ret) {
158                 /* Failure case... */
159                 up_write(&sb->s_umount);
160                 deactivate_super(sb);
161                 return ERR_PTR(ret);
162         }
163
164         sb->s_flags |= MS_ACTIVE;
165         return sb;
166
167  out_put:
168         kfree(c);
169         put_mtd_device(mtd);
170
171         return sb;
172 }
173
174 static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type,
175                                               int flags, const char *dev_name,
176                                               void *data, int mtdnr)
177 {
178         struct mtd_info *mtd;
179
180         mtd = get_mtd_device(NULL, mtdnr);
181         if (!mtd) {
182                 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr));
183                 return ERR_PTR(-EINVAL);
184         }
185
186         return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
187 }
188
189 static struct super_block *jffs2_get_sb(struct file_system_type *fs_type,
190                                         int flags, const char *dev_name,
191                                         void *data)
192 {
193         int err;
194         struct nameidata nd;
195         int mtdnr;
196
197         if (!dev_name)
198                 return ERR_PTR(-EINVAL);
199
200         D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name));
201
202         /* The preferred way of mounting in future; especially when
203            CONFIG_BLK_DEV is implemented - we specify the underlying
204            MTD device by number or by name, so that we don't require
205            block device support to be present in the kernel. */
206
207         /* FIXME: How to do the root fs this way? */
208
209         if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
210                 /* Probably mounting without the blkdev crap */
211                 if (dev_name[3] == ':') {
212                         struct mtd_info *mtd;
213
214                         /* Mount by MTD device name */
215                         D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4));
216                         for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) {
217                                 mtd = get_mtd_device(NULL, mtdnr);
218                                 if (mtd) {
219                                         if (!strcmp(mtd->name, dev_name+4))
220                                                 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd);
221                                         put_mtd_device(mtd);
222                                 }
223                         }
224                         printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4);
225                 } else if (isdigit(dev_name[3])) {
226                         /* Mount by MTD device number name */
227                         char *endptr;
228
229                         mtdnr = simple_strtoul(dev_name+3, &endptr, 0);
230                         if (!*endptr) {
231                                 /* It was a valid number */
232                                 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr));
233                                 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
234                         }
235                 }
236         }
237
238         /* Try the old way - the hack where we allowed users to mount
239            /dev/mtdblock$(n) but didn't actually _use_ the blkdev */
240
241         err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd);
242
243         D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n",
244                   err, nd.dentry->d_inode));
245
246         if (err)
247                 return ERR_PTR(err);
248
249         err = -EINVAL;
250
251         if (!S_ISBLK(nd.dentry->d_inode->i_mode))
252                 goto out;
253
254         if (nd.mnt->mnt_flags & MNT_NODEV) {
255                 err = -EACCES;
256                 goto out;
257         }
258
259         if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) {
260                 if (!(flags & MS_SILENT))
261                         printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n",
262                                dev_name);
263                 goto out;
264         }
265
266         mtdnr = iminor(nd.dentry->d_inode);
267         path_release(&nd);
268
269         return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr);
270
271 out:
272         path_release(&nd);
273         return ERR_PTR(err);
274 }
275
276 static void jffs2_put_super (struct super_block *sb)
277 {
278         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
279
280         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
281
282         down(&c->alloc_sem);
283         jffs2_flush_wbuf_pad(c);
284         up(&c->alloc_sem);
285
286         jffs2_sum_exit(c);
287
288         jffs2_free_ino_caches(c);
289         jffs2_free_raw_node_refs(c);
290         if (jffs2_blocks_use_vmalloc(c))
291                 vfree(c->blocks);
292         else
293                 kfree(c->blocks);
294         jffs2_flash_cleanup(c);
295         kfree(c->inocache_list);
296         if (c->mtd->sync)
297                 c->mtd->sync(c->mtd);
298
299         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
300 }
301
302 static void jffs2_kill_sb(struct super_block *sb)
303 {
304         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
305         if (!(sb->s_flags & MS_RDONLY))
306                 jffs2_stop_garbage_collect_thread(c);
307         generic_shutdown_super(sb);
308         put_mtd_device(c->mtd);
309         kfree(c);
310 }
311
312 static struct file_system_type jffs2_fs_type = {
313         .owner =        THIS_MODULE,
314         .name =         "jffs2",
315         .get_sb =       jffs2_get_sb,
316         .kill_sb =      jffs2_kill_sb,
317 };
318
319 static int __init init_jffs2_fs(void)
320 {
321         int ret;
322
323         printk(KERN_INFO "JFFS2 version 2.2."
324 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
325                " (NAND)"
326 #endif
327 #ifdef CONFIG_JFFS2_SUMMARY
328                " (SUMMARY) "
329 #endif
330                " (C) 2001-2003 Red Hat, Inc.\n");
331
332         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
333                                              sizeof(struct jffs2_inode_info),
334                                              0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
335                                              jffs2_i_init_once, NULL);
336         if (!jffs2_inode_cachep) {
337                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
338                 return -ENOMEM;
339         }
340         ret = jffs2_compressors_init();
341         if (ret) {
342                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
343                 goto out;
344         }
345         ret = jffs2_create_slab_caches();
346         if (ret) {
347                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
348                 goto out_compressors;
349         }
350         ret = register_filesystem(&jffs2_fs_type);
351         if (ret) {
352                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
353                 goto out_slab;
354         }
355         return 0;
356
357  out_slab:
358         jffs2_destroy_slab_caches();
359  out_compressors:
360         jffs2_compressors_exit();
361  out:
362         kmem_cache_destroy(jffs2_inode_cachep);
363         return ret;
364 }
365
366 static void __exit exit_jffs2_fs(void)
367 {
368         unregister_filesystem(&jffs2_fs_type);
369         jffs2_destroy_slab_caches();
370         jffs2_compressors_exit();
371         kmem_cache_destroy(jffs2_inode_cachep);
372 }
373
374 module_init(init_jffs2_fs);
375 module_exit(exit_jffs2_fs);
376
377 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
378 MODULE_AUTHOR("Red Hat, Inc.");
379 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
380                        // the sake of this tag. It's Free Software.