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 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 51 52 kfree(f->target); 53 kmem_cache_free(jffs2_inode_cachep, f); 54 } 55 56 static void jffs2_destroy_inode(struct inode *inode) 57 { 58 call_rcu(&inode->i_rcu, jffs2_i_callback); 59 } 60 61 static void jffs2_i_init_once(void *foo) 62 { 63 struct jffs2_inode_info *f = foo; 64 65 mutex_init(&f->sem); 66 inode_init_once(&f->vfs_inode); 67 } 68 69 static const char *jffs2_compr_name(unsigned int compr) 70 { 71 switch (compr) { 72 case JFFS2_COMPR_MODE_NONE: 73 return "none"; 74 #ifdef CONFIG_JFFS2_LZO 75 case JFFS2_COMPR_MODE_FORCELZO: 76 return "lzo"; 77 #endif 78 #ifdef CONFIG_JFFS2_ZLIB 79 case JFFS2_COMPR_MODE_FORCEZLIB: 80 return "zlib"; 81 #endif 82 default: 83 /* should never happen; programmer error */ 84 WARN_ON(1); 85 return ""; 86 } 87 } 88 89 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 90 { 91 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 92 struct jffs2_mount_opts *opts = &c->mount_opts; 93 94 if (opts->override_compr) 95 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 96 if (opts->rp_size) 97 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024); 98 99 return 0; 100 } 101 102 static int jffs2_sync_fs(struct super_block *sb, int wait) 103 { 104 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 105 106 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 107 if (jffs2_is_writebuffered(c)) 108 cancel_delayed_work_sync(&c->wbuf_dwork); 109 #endif 110 111 mutex_lock(&c->alloc_sem); 112 jffs2_flush_wbuf_pad(c); 113 mutex_unlock(&c->alloc_sem); 114 return 0; 115 } 116 117 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 118 uint32_t generation) 119 { 120 /* We don't care about i_generation. We'll destroy the flash 121 before we start re-using inode numbers anyway. And even 122 if that wasn't true, we'd have other problems...*/ 123 return jffs2_iget(sb, ino); 124 } 125 126 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 127 int fh_len, int fh_type) 128 { 129 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 130 jffs2_nfs_get_inode); 131 } 132 133 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 134 int fh_len, int fh_type) 135 { 136 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 137 jffs2_nfs_get_inode); 138 } 139 140 static struct dentry *jffs2_get_parent(struct dentry *child) 141 { 142 struct jffs2_inode_info *f; 143 uint32_t pino; 144 145 BUG_ON(!d_is_dir(child)); 146 147 f = JFFS2_INODE_INFO(d_inode(child)); 148 149 pino = f->inocache->pino_nlink; 150 151 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 152 f->inocache->ino, pino); 153 154 return d_obtain_alias(jffs2_iget(child->d_sb, pino)); 155 } 156 157 static const struct export_operations jffs2_export_ops = { 158 .get_parent = jffs2_get_parent, 159 .fh_to_dentry = jffs2_fh_to_dentry, 160 .fh_to_parent = jffs2_fh_to_parent, 161 }; 162 163 /* 164 * JFFS2 mount options. 165 * 166 * Opt_override_compr: override default compressor 167 * Opt_rp_size: size of reserved pool in KiB 168 * Opt_err: just end of array marker 169 */ 170 enum { 171 Opt_override_compr, 172 Opt_rp_size, 173 Opt_err, 174 }; 175 176 static const match_table_t tokens = { 177 {Opt_override_compr, "compr=%s"}, 178 {Opt_rp_size, "rp_size=%u"}, 179 {Opt_err, NULL}, 180 }; 181 182 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 183 { 184 substring_t args[MAX_OPT_ARGS]; 185 char *p, *name; 186 unsigned int opt; 187 188 if (!data) 189 return 0; 190 191 while ((p = strsep(&data, ","))) { 192 int token; 193 194 if (!*p) 195 continue; 196 197 token = match_token(p, tokens, args); 198 switch (token) { 199 case Opt_override_compr: 200 name = match_strdup(&args[0]); 201 202 if (!name) 203 return -ENOMEM; 204 if (!strcmp(name, "none")) 205 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 206 #ifdef CONFIG_JFFS2_LZO 207 else if (!strcmp(name, "lzo")) 208 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 209 #endif 210 #ifdef CONFIG_JFFS2_ZLIB 211 else if (!strcmp(name, "zlib")) 212 c->mount_opts.compr = 213 JFFS2_COMPR_MODE_FORCEZLIB; 214 #endif 215 else { 216 pr_err("Error: unknown compressor \"%s\"\n", 217 name); 218 kfree(name); 219 return -EINVAL; 220 } 221 kfree(name); 222 c->mount_opts.override_compr = true; 223 break; 224 case Opt_rp_size: 225 if (match_int(&args[0], &opt)) 226 return -EINVAL; 227 opt *= 1024; 228 if (opt > c->mtd->size) { 229 pr_warn("Too large reserve pool specified, max " 230 "is %llu KB\n", c->mtd->size / 1024); 231 return -EINVAL; 232 } 233 c->mount_opts.rp_size = opt; 234 break; 235 default: 236 pr_err("Error: unrecognized mount option '%s' or missing value\n", 237 p); 238 return -EINVAL; 239 } 240 } 241 242 return 0; 243 } 244 245 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 246 { 247 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 248 int err; 249 250 sync_filesystem(sb); 251 err = jffs2_parse_options(c, data); 252 if (err) 253 return -EINVAL; 254 255 return jffs2_do_remount_fs(sb, flags, data); 256 } 257 258 static const struct super_operations jffs2_super_operations = 259 { 260 .alloc_inode = jffs2_alloc_inode, 261 .destroy_inode =jffs2_destroy_inode, 262 .put_super = jffs2_put_super, 263 .statfs = jffs2_statfs, 264 .remount_fs = jffs2_remount_fs, 265 .evict_inode = jffs2_evict_inode, 266 .dirty_inode = jffs2_dirty_inode, 267 .show_options = jffs2_show_options, 268 .sync_fs = jffs2_sync_fs, 269 }; 270 271 /* 272 * fill in the superblock 273 */ 274 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 275 { 276 struct jffs2_sb_info *c; 277 int ret; 278 279 jffs2_dbg(1, "jffs2_get_sb_mtd():" 280 " New superblock for device %d (\"%s\")\n", 281 sb->s_mtd->index, sb->s_mtd->name); 282 283 c = kzalloc(sizeof(*c), GFP_KERNEL); 284 if (!c) 285 return -ENOMEM; 286 287 c->mtd = sb->s_mtd; 288 c->os_priv = sb; 289 sb->s_fs_info = c; 290 291 ret = jffs2_parse_options(c, data); 292 if (ret) 293 return -EINVAL; 294 295 /* Initialize JFFS2 superblock locks, the further initialization will 296 * be done later */ 297 mutex_init(&c->alloc_sem); 298 mutex_init(&c->erase_free_sem); 299 init_waitqueue_head(&c->erase_wait); 300 init_waitqueue_head(&c->inocache_wq); 301 spin_lock_init(&c->erase_completion_lock); 302 spin_lock_init(&c->inocache_lock); 303 304 sb->s_op = &jffs2_super_operations; 305 sb->s_export_op = &jffs2_export_ops; 306 sb->s_flags = sb->s_flags | SB_NOATIME; 307 sb->s_xattr = jffs2_xattr_handlers; 308 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 309 sb->s_flags |= SB_POSIXACL; 310 #endif 311 ret = jffs2_do_fill_super(sb, data, silent); 312 return ret; 313 } 314 315 static struct dentry *jffs2_mount(struct file_system_type *fs_type, 316 int flags, const char *dev_name, 317 void *data) 318 { 319 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); 320 } 321 322 static void jffs2_put_super (struct super_block *sb) 323 { 324 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 325 326 jffs2_dbg(2, "%s()\n", __func__); 327 328 mutex_lock(&c->alloc_sem); 329 jffs2_flush_wbuf_pad(c); 330 mutex_unlock(&c->alloc_sem); 331 332 jffs2_sum_exit(c); 333 334 jffs2_free_ino_caches(c); 335 jffs2_free_raw_node_refs(c); 336 kvfree(c->blocks); 337 jffs2_flash_cleanup(c); 338 kfree(c->inocache_list); 339 jffs2_clear_xattr_subsystem(c); 340 mtd_sync(c->mtd); 341 jffs2_dbg(1, "%s(): returning\n", __func__); 342 } 343 344 static void jffs2_kill_sb(struct super_block *sb) 345 { 346 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 347 if (c && !sb_rdonly(sb)) 348 jffs2_stop_garbage_collect_thread(c); 349 kill_mtd_super(sb); 350 kfree(c); 351 } 352 353 static struct file_system_type jffs2_fs_type = { 354 .owner = THIS_MODULE, 355 .name = "jffs2", 356 .mount = jffs2_mount, 357 .kill_sb = jffs2_kill_sb, 358 }; 359 MODULE_ALIAS_FS("jffs2"); 360 361 static int __init init_jffs2_fs(void) 362 { 363 int ret; 364 365 /* Paranoia checks for on-medium structures. If we ask GCC 366 to pack them with __attribute__((packed)) then it _also_ 367 assumes that they're not aligned -- so it emits crappy 368 code on some architectures. Ideally we want an attribute 369 which means just 'no padding', without the alignment 370 thing. But GCC doesn't have that -- we have to just 371 hope the structs are the right sizes, instead. */ 372 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 373 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 374 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 375 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 376 377 pr_info("version 2.2." 378 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 379 " (NAND)" 380 #endif 381 #ifdef CONFIG_JFFS2_SUMMARY 382 " (SUMMARY) " 383 #endif 384 " © 2001-2006 Red Hat, Inc.\n"); 385 386 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 387 sizeof(struct jffs2_inode_info), 388 0, (SLAB_RECLAIM_ACCOUNT| 389 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 390 jffs2_i_init_once); 391 if (!jffs2_inode_cachep) { 392 pr_err("error: Failed to initialise inode cache\n"); 393 return -ENOMEM; 394 } 395 ret = jffs2_compressors_init(); 396 if (ret) { 397 pr_err("error: Failed to initialise compressors\n"); 398 goto out; 399 } 400 ret = jffs2_create_slab_caches(); 401 if (ret) { 402 pr_err("error: Failed to initialise slab caches\n"); 403 goto out_compressors; 404 } 405 ret = register_filesystem(&jffs2_fs_type); 406 if (ret) { 407 pr_err("error: Failed to register filesystem\n"); 408 goto out_slab; 409 } 410 return 0; 411 412 out_slab: 413 jffs2_destroy_slab_caches(); 414 out_compressors: 415 jffs2_compressors_exit(); 416 out: 417 kmem_cache_destroy(jffs2_inode_cachep); 418 return ret; 419 } 420 421 static void __exit exit_jffs2_fs(void) 422 { 423 unregister_filesystem(&jffs2_fs_type); 424 jffs2_destroy_slab_caches(); 425 jffs2_compressors_exit(); 426 427 /* 428 * Make sure all delayed rcu free inodes are flushed before we 429 * destroy cache. 430 */ 431 rcu_barrier(); 432 kmem_cache_destroy(jffs2_inode_cachep); 433 } 434 435 module_init(init_jffs2_fs); 436 module_exit(exit_jffs2_fs); 437 438 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 439 MODULE_AUTHOR("Red Hat, Inc."); 440 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 441 // the sake of this tag. It's Free Software. 442