1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 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 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 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> 19 #include <linux/fs.h> 20 #include <linux/err.h> 21 #include <linux/mount.h> 22 #include <linux/parser.h> 23 #include <linux/jffs2.h> 24 #include <linux/pagemap.h> 25 #include <linux/mtd/super.h> 26 #include <linux/ctype.h> 27 #include <linux/namei.h> 28 #include <linux/seq_file.h> 29 #include <linux/exportfs.h> 30 #include "compr.h" 31 #include "nodelist.h" 32 33 static void jffs2_put_super(struct super_block *); 34 35 static struct kmem_cache *jffs2_inode_cachep; 36 37 static struct inode *jffs2_alloc_inode(struct super_block *sb) 38 { 39 struct jffs2_inode_info *f; 40 41 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 42 if (!f) 43 return NULL; 44 return &f->vfs_inode; 45 } 46 47 static void jffs2_i_callback(struct rcu_head *head) 48 { 49 struct inode *inode = container_of(head, struct inode, i_rcu); 50 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 51 } 52 53 static void jffs2_destroy_inode(struct inode *inode) 54 { 55 call_rcu(&inode->i_rcu, jffs2_i_callback); 56 } 57 58 static void jffs2_i_init_once(void *foo) 59 { 60 struct jffs2_inode_info *f = foo; 61 62 mutex_init(&f->sem); 63 inode_init_once(&f->vfs_inode); 64 } 65 66 static const char *jffs2_compr_name(unsigned int compr) 67 { 68 switch (compr) { 69 case JFFS2_COMPR_MODE_NONE: 70 return "none"; 71 #ifdef CONFIG_JFFS2_LZO 72 case JFFS2_COMPR_MODE_FORCELZO: 73 return "lzo"; 74 #endif 75 #ifdef CONFIG_JFFS2_ZLIB 76 case JFFS2_COMPR_MODE_FORCEZLIB: 77 return "zlib"; 78 #endif 79 default: 80 /* should never happen; programmer error */ 81 WARN_ON(1); 82 return ""; 83 } 84 } 85 86 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 87 { 88 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 89 struct jffs2_mount_opts *opts = &c->mount_opts; 90 91 if (opts->override_compr) 92 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 93 if (opts->rp_size) 94 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024); 95 96 return 0; 97 } 98 99 static int jffs2_sync_fs(struct super_block *sb, int wait) 100 { 101 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 102 103 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 104 if (jffs2_is_writebuffered(c)) 105 cancel_delayed_work_sync(&c->wbuf_dwork); 106 #endif 107 108 mutex_lock(&c->alloc_sem); 109 jffs2_flush_wbuf_pad(c); 110 mutex_unlock(&c->alloc_sem); 111 return 0; 112 } 113 114 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 115 uint32_t generation) 116 { 117 /* We don't care about i_generation. We'll destroy the flash 118 before we start re-using inode numbers anyway. And even 119 if that wasn't true, we'd have other problems...*/ 120 return jffs2_iget(sb, ino); 121 } 122 123 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 124 int fh_len, int fh_type) 125 { 126 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 127 jffs2_nfs_get_inode); 128 } 129 130 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 131 int fh_len, int fh_type) 132 { 133 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 134 jffs2_nfs_get_inode); 135 } 136 137 static struct dentry *jffs2_get_parent(struct dentry *child) 138 { 139 struct jffs2_inode_info *f; 140 uint32_t pino; 141 142 BUG_ON(!d_is_dir(child)); 143 144 f = JFFS2_INODE_INFO(d_inode(child)); 145 146 pino = f->inocache->pino_nlink; 147 148 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 149 f->inocache->ino, pino); 150 151 return d_obtain_alias(jffs2_iget(child->d_sb, pino)); 152 } 153 154 static const struct export_operations jffs2_export_ops = { 155 .get_parent = jffs2_get_parent, 156 .fh_to_dentry = jffs2_fh_to_dentry, 157 .fh_to_parent = jffs2_fh_to_parent, 158 }; 159 160 /* 161 * JFFS2 mount options. 162 * 163 * Opt_override_compr: override default compressor 164 * Opt_rp_size: size of reserved pool in KiB 165 * Opt_err: just end of array marker 166 */ 167 enum { 168 Opt_override_compr, 169 Opt_rp_size, 170 Opt_err, 171 }; 172 173 static const match_table_t tokens = { 174 {Opt_override_compr, "compr=%s"}, 175 {Opt_rp_size, "rp_size=%u"}, 176 {Opt_err, NULL}, 177 }; 178 179 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 180 { 181 substring_t args[MAX_OPT_ARGS]; 182 char *p, *name; 183 unsigned int opt; 184 185 if (!data) 186 return 0; 187 188 while ((p = strsep(&data, ","))) { 189 int token; 190 191 if (!*p) 192 continue; 193 194 token = match_token(p, tokens, args); 195 switch (token) { 196 case Opt_override_compr: 197 name = match_strdup(&args[0]); 198 199 if (!name) 200 return -ENOMEM; 201 if (!strcmp(name, "none")) 202 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 203 #ifdef CONFIG_JFFS2_LZO 204 else if (!strcmp(name, "lzo")) 205 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 206 #endif 207 #ifdef CONFIG_JFFS2_ZLIB 208 else if (!strcmp(name, "zlib")) 209 c->mount_opts.compr = 210 JFFS2_COMPR_MODE_FORCEZLIB; 211 #endif 212 else { 213 pr_err("Error: unknown compressor \"%s\"\n", 214 name); 215 kfree(name); 216 return -EINVAL; 217 } 218 kfree(name); 219 c->mount_opts.override_compr = true; 220 break; 221 case Opt_rp_size: 222 if (match_int(&args[0], &opt)) 223 return -EINVAL; 224 opt *= 1024; 225 if (opt > c->mtd->size) { 226 pr_warn("Too large reserve pool specified, max " 227 "is %llu KB\n", c->mtd->size / 1024); 228 return -EINVAL; 229 } 230 c->mount_opts.rp_size = opt; 231 break; 232 default: 233 pr_err("Error: unrecognized mount option '%s' or missing value\n", 234 p); 235 return -EINVAL; 236 } 237 } 238 239 return 0; 240 } 241 242 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 243 { 244 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 245 int err; 246 247 sync_filesystem(sb); 248 err = jffs2_parse_options(c, data); 249 if (err) 250 return -EINVAL; 251 252 return jffs2_do_remount_fs(sb, flags, data); 253 } 254 255 static const struct super_operations jffs2_super_operations = 256 { 257 .alloc_inode = jffs2_alloc_inode, 258 .destroy_inode =jffs2_destroy_inode, 259 .put_super = jffs2_put_super, 260 .statfs = jffs2_statfs, 261 .remount_fs = jffs2_remount_fs, 262 .evict_inode = jffs2_evict_inode, 263 .dirty_inode = jffs2_dirty_inode, 264 .show_options = jffs2_show_options, 265 .sync_fs = jffs2_sync_fs, 266 }; 267 268 /* 269 * fill in the superblock 270 */ 271 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 272 { 273 struct jffs2_sb_info *c; 274 int ret; 275 276 jffs2_dbg(1, "jffs2_get_sb_mtd():" 277 " New superblock for device %d (\"%s\")\n", 278 sb->s_mtd->index, sb->s_mtd->name); 279 280 c = kzalloc(sizeof(*c), GFP_KERNEL); 281 if (!c) 282 return -ENOMEM; 283 284 c->mtd = sb->s_mtd; 285 c->os_priv = sb; 286 sb->s_fs_info = c; 287 288 ret = jffs2_parse_options(c, data); 289 if (ret) 290 return -EINVAL; 291 292 /* Initialize JFFS2 superblock locks, the further initialization will 293 * be done later */ 294 mutex_init(&c->alloc_sem); 295 mutex_init(&c->erase_free_sem); 296 init_waitqueue_head(&c->erase_wait); 297 init_waitqueue_head(&c->inocache_wq); 298 spin_lock_init(&c->erase_completion_lock); 299 spin_lock_init(&c->inocache_lock); 300 301 sb->s_op = &jffs2_super_operations; 302 sb->s_export_op = &jffs2_export_ops; 303 sb->s_flags = sb->s_flags | SB_NOATIME; 304 sb->s_xattr = jffs2_xattr_handlers; 305 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 306 sb->s_flags |= SB_POSIXACL; 307 #endif 308 ret = jffs2_do_fill_super(sb, data, silent); 309 return ret; 310 } 311 312 static struct dentry *jffs2_mount(struct file_system_type *fs_type, 313 int flags, const char *dev_name, 314 void *data) 315 { 316 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); 317 } 318 319 static void jffs2_put_super (struct super_block *sb) 320 { 321 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 322 323 jffs2_dbg(2, "%s()\n", __func__); 324 325 mutex_lock(&c->alloc_sem); 326 jffs2_flush_wbuf_pad(c); 327 mutex_unlock(&c->alloc_sem); 328 329 jffs2_sum_exit(c); 330 331 jffs2_free_ino_caches(c); 332 jffs2_free_raw_node_refs(c); 333 kvfree(c->blocks); 334 jffs2_flash_cleanup(c); 335 kfree(c->inocache_list); 336 jffs2_clear_xattr_subsystem(c); 337 mtd_sync(c->mtd); 338 jffs2_dbg(1, "%s(): returning\n", __func__); 339 } 340 341 static void jffs2_kill_sb(struct super_block *sb) 342 { 343 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 344 if (c && !sb_rdonly(sb)) 345 jffs2_stop_garbage_collect_thread(c); 346 kill_mtd_super(sb); 347 kfree(c); 348 } 349 350 static struct file_system_type jffs2_fs_type = { 351 .owner = THIS_MODULE, 352 .name = "jffs2", 353 .mount = jffs2_mount, 354 .kill_sb = jffs2_kill_sb, 355 }; 356 MODULE_ALIAS_FS("jffs2"); 357 358 static int __init init_jffs2_fs(void) 359 { 360 int ret; 361 362 /* Paranoia checks for on-medium structures. If we ask GCC 363 to pack them with __attribute__((packed)) then it _also_ 364 assumes that they're not aligned -- so it emits crappy 365 code on some architectures. Ideally we want an attribute 366 which means just 'no padding', without the alignment 367 thing. But GCC doesn't have that -- we have to just 368 hope the structs are the right sizes, instead. */ 369 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 370 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 371 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 372 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 373 374 pr_info("version 2.2." 375 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 376 " (NAND)" 377 #endif 378 #ifdef CONFIG_JFFS2_SUMMARY 379 " (SUMMARY) " 380 #endif 381 " © 2001-2006 Red Hat, Inc.\n"); 382 383 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 384 sizeof(struct jffs2_inode_info), 385 0, (SLAB_RECLAIM_ACCOUNT| 386 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 387 jffs2_i_init_once); 388 if (!jffs2_inode_cachep) { 389 pr_err("error: Failed to initialise inode cache\n"); 390 return -ENOMEM; 391 } 392 ret = jffs2_compressors_init(); 393 if (ret) { 394 pr_err("error: Failed to initialise compressors\n"); 395 goto out; 396 } 397 ret = jffs2_create_slab_caches(); 398 if (ret) { 399 pr_err("error: Failed to initialise slab caches\n"); 400 goto out_compressors; 401 } 402 ret = register_filesystem(&jffs2_fs_type); 403 if (ret) { 404 pr_err("error: Failed to register filesystem\n"); 405 goto out_slab; 406 } 407 return 0; 408 409 out_slab: 410 jffs2_destroy_slab_caches(); 411 out_compressors: 412 jffs2_compressors_exit(); 413 out: 414 kmem_cache_destroy(jffs2_inode_cachep); 415 return ret; 416 } 417 418 static void __exit exit_jffs2_fs(void) 419 { 420 unregister_filesystem(&jffs2_fs_type); 421 jffs2_destroy_slab_caches(); 422 jffs2_compressors_exit(); 423 424 /* 425 * Make sure all delayed rcu free inodes are flushed before we 426 * destroy cache. 427 */ 428 rcu_barrier(); 429 kmem_cache_destroy(jffs2_inode_cachep); 430 } 431 432 module_init(init_jffs2_fs); 433 module_exit(exit_jffs2_fs); 434 435 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 436 MODULE_AUTHOR("Red Hat, Inc."); 437 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 438 // the sake of this tag. It's Free Software. 439