2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright © 2001-2007 Red Hat, Inc.
6 * Created by David Woodhouse <dwmw2@infradead.org>
8 * For licensing information, see the file 'LICENCE' in this directory.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/init.h>
18 #include <linux/list.h>
20 #include <linux/err.h>
21 #include <linux/mount.h>
22 #include <linux/fs_context.h>
23 #include <linux/fs_parser.h>
24 #include <linux/jffs2.h>
25 #include <linux/pagemap.h>
26 #include <linux/mtd/super.h>
27 #include <linux/ctype.h>
28 #include <linux/namei.h>
29 #include <linux/seq_file.h>
30 #include <linux/exportfs.h>
34 static void jffs2_put_super(struct super_block *);
36 static struct kmem_cache *jffs2_inode_cachep;
38 static struct inode *jffs2_alloc_inode(struct super_block *sb)
40 struct jffs2_inode_info *f;
42 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
48 static void jffs2_free_inode(struct inode *inode)
50 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
53 kmem_cache_free(jffs2_inode_cachep, f);
56 static void jffs2_i_init_once(void *foo)
58 struct jffs2_inode_info *f = foo;
61 inode_init_once(&f->vfs_inode);
64 static const char *jffs2_compr_name(unsigned int compr)
67 case JFFS2_COMPR_MODE_NONE:
69 #ifdef CONFIG_JFFS2_LZO
70 case JFFS2_COMPR_MODE_FORCELZO:
73 #ifdef CONFIG_JFFS2_ZLIB
74 case JFFS2_COMPR_MODE_FORCEZLIB:
78 /* should never happen; programmer error */
84 static int jffs2_show_options(struct seq_file *s, struct dentry *root)
86 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb);
87 struct jffs2_mount_opts *opts = &c->mount_opts;
89 if (opts->override_compr)
90 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr));
92 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024);
97 static int jffs2_sync_fs(struct super_block *sb, int wait)
99 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
101 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
102 if (jffs2_is_writebuffered(c))
103 cancel_delayed_work_sync(&c->wbuf_dwork);
106 mutex_lock(&c->alloc_sem);
107 jffs2_flush_wbuf_pad(c);
108 mutex_unlock(&c->alloc_sem);
112 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
115 /* We don't care about i_generation. We'll destroy the flash
116 before we start re-using inode numbers anyway. And even
117 if that wasn't true, we'd have other problems...*/
118 return jffs2_iget(sb, ino);
121 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid,
122 int fh_len, int fh_type)
124 return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
125 jffs2_nfs_get_inode);
128 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid,
129 int fh_len, int fh_type)
131 return generic_fh_to_parent(sb, fid, fh_len, fh_type,
132 jffs2_nfs_get_inode);
135 static struct dentry *jffs2_get_parent(struct dentry *child)
137 struct jffs2_inode_info *f;
140 BUG_ON(!d_is_dir(child));
142 f = JFFS2_INODE_INFO(d_inode(child));
144 pino = f->inocache->pino_nlink;
146 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n",
147 f->inocache->ino, pino);
149 return d_obtain_alias(jffs2_iget(child->d_sb, pino));
152 static const struct export_operations jffs2_export_ops = {
153 .get_parent = jffs2_get_parent,
154 .fh_to_dentry = jffs2_fh_to_dentry,
155 .fh_to_parent = jffs2_fh_to_parent,
159 * JFFS2 mount options.
161 * Opt_source: The source device
162 * Opt_override_compr: override default compressor
163 * Opt_rp_size: size of reserved pool in KiB
170 static const struct constant_table jffs2_param_compr[] = {
171 {"none", JFFS2_COMPR_MODE_NONE },
172 #ifdef CONFIG_JFFS2_LZO
173 {"lzo", JFFS2_COMPR_MODE_FORCELZO },
175 #ifdef CONFIG_JFFS2_ZLIB
176 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB },
181 static const struct fs_parameter_spec jffs2_param_specs[] = {
182 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr),
183 fsparam_u32 ("rp_size", Opt_rp_size),
187 const struct fs_parameter_description jffs2_fs_parameters = {
188 .specs = jffs2_param_specs,
191 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
193 struct fs_parse_result result;
194 struct jffs2_sb_info *c = fc->s_fs_info;
197 opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
202 case Opt_override_compr:
203 c->mount_opts.compr = result.uint_32;
204 c->mount_opts.override_compr = true;
207 if (result.uint_32 > UINT_MAX / 1024)
208 return invalf(fc, "jffs2: rp_size unrepresentable");
209 opt = result.uint_32 * 1024;
210 if (opt > c->mtd->size)
211 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
212 c->mtd->size / 1024);
213 c->mount_opts.rp_size = opt;
222 static int jffs2_reconfigure(struct fs_context *fc)
224 struct super_block *sb = fc->root->d_sb;
227 return jffs2_do_remount_fs(sb, fc);
230 static const struct super_operations jffs2_super_operations =
232 .alloc_inode = jffs2_alloc_inode,
233 .free_inode = jffs2_free_inode,
234 .put_super = jffs2_put_super,
235 .statfs = jffs2_statfs,
236 .evict_inode = jffs2_evict_inode,
237 .dirty_inode = jffs2_dirty_inode,
238 .show_options = jffs2_show_options,
239 .sync_fs = jffs2_sync_fs,
243 * fill in the superblock
245 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
247 struct jffs2_sb_info *c = sb->s_fs_info;
249 jffs2_dbg(1, "jffs2_get_sb_mtd():"
250 " New superblock for device %d (\"%s\")\n",
251 sb->s_mtd->index, sb->s_mtd->name);
256 /* Initialize JFFS2 superblock locks, the further initialization will
258 mutex_init(&c->alloc_sem);
259 mutex_init(&c->erase_free_sem);
260 init_waitqueue_head(&c->erase_wait);
261 init_waitqueue_head(&c->inocache_wq);
262 spin_lock_init(&c->erase_completion_lock);
263 spin_lock_init(&c->inocache_lock);
265 sb->s_op = &jffs2_super_operations;
266 sb->s_export_op = &jffs2_export_ops;
267 sb->s_flags = sb->s_flags | SB_NOATIME;
268 sb->s_xattr = jffs2_xattr_handlers;
269 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
270 sb->s_flags |= SB_POSIXACL;
272 return jffs2_do_fill_super(sb, fc);
275 static int jffs2_get_tree(struct fs_context *fc)
277 return get_tree_mtd(fc, jffs2_fill_super);
280 static void jffs2_free_fc(struct fs_context *fc)
282 kfree(fc->s_fs_info);
285 static const struct fs_context_operations jffs2_context_ops = {
286 .free = jffs2_free_fc,
287 .parse_param = jffs2_parse_param,
288 .get_tree = jffs2_get_tree,
289 .reconfigure = jffs2_reconfigure,
292 static int jffs2_init_fs_context(struct fs_context *fc)
294 struct jffs2_sb_info *ctx;
296 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
301 fc->ops = &jffs2_context_ops;
305 static void jffs2_put_super (struct super_block *sb)
307 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
309 jffs2_dbg(2, "%s()\n", __func__);
311 mutex_lock(&c->alloc_sem);
312 jffs2_flush_wbuf_pad(c);
313 mutex_unlock(&c->alloc_sem);
317 jffs2_free_ino_caches(c);
318 jffs2_free_raw_node_refs(c);
320 jffs2_flash_cleanup(c);
321 kfree(c->inocache_list);
322 jffs2_clear_xattr_subsystem(c);
324 jffs2_dbg(1, "%s(): returning\n", __func__);
327 static void jffs2_kill_sb(struct super_block *sb)
329 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
330 if (c && !sb_rdonly(sb))
331 jffs2_stop_garbage_collect_thread(c);
336 static struct file_system_type jffs2_fs_type = {
337 .owner = THIS_MODULE,
339 .init_fs_context = jffs2_init_fs_context,
340 .parameters = &jffs2_fs_parameters,
341 .kill_sb = jffs2_kill_sb,
343 MODULE_ALIAS_FS("jffs2");
345 static int __init init_jffs2_fs(void)
349 /* Paranoia checks for on-medium structures. If we ask GCC
350 to pack them with __attribute__((packed)) then it _also_
351 assumes that they're not aligned -- so it emits crappy
352 code on some architectures. Ideally we want an attribute
353 which means just 'no padding', without the alignment
354 thing. But GCC doesn't have that -- we have to just
355 hope the structs are the right sizes, instead. */
356 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
357 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
358 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
359 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
361 pr_info("version 2.2."
362 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
365 #ifdef CONFIG_JFFS2_SUMMARY
368 " © 2001-2006 Red Hat, Inc.\n");
370 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
371 sizeof(struct jffs2_inode_info),
372 0, (SLAB_RECLAIM_ACCOUNT|
373 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
375 if (!jffs2_inode_cachep) {
376 pr_err("error: Failed to initialise inode cache\n");
379 ret = jffs2_compressors_init();
381 pr_err("error: Failed to initialise compressors\n");
384 ret = jffs2_create_slab_caches();
386 pr_err("error: Failed to initialise slab caches\n");
387 goto out_compressors;
389 ret = register_filesystem(&jffs2_fs_type);
391 pr_err("error: Failed to register filesystem\n");
397 jffs2_destroy_slab_caches();
399 jffs2_compressors_exit();
401 kmem_cache_destroy(jffs2_inode_cachep);
405 static void __exit exit_jffs2_fs(void)
407 unregister_filesystem(&jffs2_fs_type);
408 jffs2_destroy_slab_caches();
409 jffs2_compressors_exit();
412 * Make sure all delayed rcu free inodes are flushed before we
416 kmem_cache_destroy(jffs2_inode_cachep);
419 module_init(init_jffs2_fs);
420 module_exit(exit_jffs2_fs);
422 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
423 MODULE_AUTHOR("Red Hat, Inc.");
424 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
425 // the sake of this tag. It's Free Software.