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));
91 if (opts->set_rp_size)
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 fs_parameter_spec jffs2_param_specs[] = {
171 fsparam_enum ("compr", Opt_override_compr),
172 fsparam_u32 ("rp_size", Opt_rp_size),
176 static const struct fs_parameter_enum jffs2_param_enums[] = {
177 { Opt_override_compr, "none", JFFS2_COMPR_MODE_NONE },
178 #ifdef CONFIG_JFFS2_LZO
179 { Opt_override_compr, "lzo", JFFS2_COMPR_MODE_FORCELZO },
181 #ifdef CONFIG_JFFS2_ZLIB
182 { Opt_override_compr, "zlib", JFFS2_COMPR_MODE_FORCEZLIB },
187 const struct fs_parameter_description jffs2_fs_parameters = {
189 .specs = jffs2_param_specs,
190 .enums = jffs2_param_enums,
193 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
195 struct fs_parse_result result;
196 struct jffs2_sb_info *c = fc->s_fs_info;
199 opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
204 case Opt_override_compr:
205 c->mount_opts.compr = result.uint_32;
206 c->mount_opts.override_compr = true;
209 if (result.uint_32 > UINT_MAX / 1024)
210 return invalf(fc, "jffs2: rp_size unrepresentable");
211 c->mount_opts.rp_size = result.uint_32 * 1024;
212 c->mount_opts.set_rp_size = true;
221 static inline void jffs2_update_mount_opts(struct fs_context *fc)
223 struct jffs2_sb_info *new_c = fc->s_fs_info;
224 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb);
226 mutex_lock(&c->alloc_sem);
227 if (new_c->mount_opts.override_compr) {
228 c->mount_opts.override_compr = new_c->mount_opts.override_compr;
229 c->mount_opts.compr = new_c->mount_opts.compr;
231 if (new_c->mount_opts.set_rp_size) {
232 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size;
233 c->mount_opts.rp_size = new_c->mount_opts.rp_size;
235 mutex_unlock(&c->alloc_sem);
238 static int jffs2_reconfigure(struct fs_context *fc)
240 struct super_block *sb = fc->root->d_sb;
243 jffs2_update_mount_opts(fc);
245 return jffs2_do_remount_fs(sb, fc);
248 static const struct super_operations jffs2_super_operations =
250 .alloc_inode = jffs2_alloc_inode,
251 .free_inode = jffs2_free_inode,
252 .put_super = jffs2_put_super,
253 .statfs = jffs2_statfs,
254 .evict_inode = jffs2_evict_inode,
255 .dirty_inode = jffs2_dirty_inode,
256 .show_options = jffs2_show_options,
257 .sync_fs = jffs2_sync_fs,
261 * fill in the superblock
263 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
265 struct jffs2_sb_info *c = sb->s_fs_info;
267 jffs2_dbg(1, "jffs2_get_sb_mtd():"
268 " New superblock for device %d (\"%s\")\n",
269 sb->s_mtd->index, sb->s_mtd->name);
274 if (c->mount_opts.rp_size > c->mtd->size)
275 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
276 c->mtd->size / 1024);
278 /* Initialize JFFS2 superblock locks, the further initialization will
280 mutex_init(&c->alloc_sem);
281 mutex_init(&c->erase_free_sem);
282 init_waitqueue_head(&c->erase_wait);
283 init_waitqueue_head(&c->inocache_wq);
284 spin_lock_init(&c->erase_completion_lock);
285 spin_lock_init(&c->inocache_lock);
287 sb->s_op = &jffs2_super_operations;
288 sb->s_export_op = &jffs2_export_ops;
289 sb->s_flags = sb->s_flags | SB_NOATIME;
290 sb->s_xattr = jffs2_xattr_handlers;
291 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
292 sb->s_flags |= SB_POSIXACL;
294 return jffs2_do_fill_super(sb, fc);
297 static int jffs2_get_tree(struct fs_context *fc)
299 return get_tree_mtd(fc, jffs2_fill_super);
302 static void jffs2_free_fc(struct fs_context *fc)
304 kfree(fc->s_fs_info);
307 static const struct fs_context_operations jffs2_context_ops = {
308 .free = jffs2_free_fc,
309 .parse_param = jffs2_parse_param,
310 .get_tree = jffs2_get_tree,
311 .reconfigure = jffs2_reconfigure,
314 static int jffs2_init_fs_context(struct fs_context *fc)
316 struct jffs2_sb_info *ctx;
318 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
323 fc->ops = &jffs2_context_ops;
327 static void jffs2_put_super (struct super_block *sb)
329 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
331 jffs2_dbg(2, "%s()\n", __func__);
333 mutex_lock(&c->alloc_sem);
334 jffs2_flush_wbuf_pad(c);
335 mutex_unlock(&c->alloc_sem);
339 jffs2_free_ino_caches(c);
340 jffs2_free_raw_node_refs(c);
342 jffs2_flash_cleanup(c);
343 kfree(c->inocache_list);
344 jffs2_clear_xattr_subsystem(c);
346 jffs2_dbg(1, "%s(): returning\n", __func__);
349 static void jffs2_kill_sb(struct super_block *sb)
351 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
352 if (c && !sb_rdonly(sb))
353 jffs2_stop_garbage_collect_thread(c);
358 static struct file_system_type jffs2_fs_type = {
359 .owner = THIS_MODULE,
361 .init_fs_context = jffs2_init_fs_context,
362 .parameters = &jffs2_fs_parameters,
363 .kill_sb = jffs2_kill_sb,
365 MODULE_ALIAS_FS("jffs2");
367 static int __init init_jffs2_fs(void)
371 /* Paranoia checks for on-medium structures. If we ask GCC
372 to pack them with __attribute__((packed)) then it _also_
373 assumes that they're not aligned -- so it emits crappy
374 code on some architectures. Ideally we want an attribute
375 which means just 'no padding', without the alignment
376 thing. But GCC doesn't have that -- we have to just
377 hope the structs are the right sizes, instead. */
378 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
379 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
380 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
381 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
383 pr_info("version 2.2."
384 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
387 #ifdef CONFIG_JFFS2_SUMMARY
390 " © 2001-2006 Red Hat, Inc.\n");
392 jffs2_inode_cachep = kmem_cache_create("jffs2_i",
393 sizeof(struct jffs2_inode_info),
394 0, (SLAB_RECLAIM_ACCOUNT|
395 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
397 if (!jffs2_inode_cachep) {
398 pr_err("error: Failed to initialise inode cache\n");
401 ret = jffs2_compressors_init();
403 pr_err("error: Failed to initialise compressors\n");
406 ret = jffs2_create_slab_caches();
408 pr_err("error: Failed to initialise slab caches\n");
409 goto out_compressors;
411 ret = register_filesystem(&jffs2_fs_type);
413 pr_err("error: Failed to register filesystem\n");
419 jffs2_destroy_slab_caches();
421 jffs2_compressors_exit();
423 kmem_cache_destroy(jffs2_inode_cachep);
427 static void __exit exit_jffs2_fs(void)
429 unregister_filesystem(&jffs2_fs_type);
430 jffs2_destroy_slab_caches();
431 jffs2_compressors_exit();
434 * Make sure all delayed rcu free inodes are flushed before we
438 kmem_cache_destroy(jffs2_inode_cachep);
441 module_init(init_jffs2_fs);
442 module_exit(exit_jffs2_fs);
444 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
445 MODULE_AUTHOR("Red Hat, Inc.");
446 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
447 // the sake of this tag. It's Free Software.