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 cancel_delayed_work_sync(&c->wbuf_dwork); 105 #endif 106 107 mutex_lock(&c->alloc_sem); 108 jffs2_flush_wbuf_pad(c); 109 mutex_unlock(&c->alloc_sem); 110 return 0; 111 } 112 113 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 114 uint32_t generation) 115 { 116 /* We don't care about i_generation. We'll destroy the flash 117 before we start re-using inode numbers anyway. And even 118 if that wasn't true, we'd have other problems...*/ 119 return jffs2_iget(sb, ino); 120 } 121 122 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 123 int fh_len, int fh_type) 124 { 125 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 126 jffs2_nfs_get_inode); 127 } 128 129 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 130 int fh_len, int fh_type) 131 { 132 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 133 jffs2_nfs_get_inode); 134 } 135 136 static struct dentry *jffs2_get_parent(struct dentry *child) 137 { 138 struct jffs2_inode_info *f; 139 uint32_t pino; 140 141 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 142 143 f = JFFS2_INODE_INFO(child->d_inode); 144 145 pino = f->inocache->pino_nlink; 146 147 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 148 f->inocache->ino, pino); 149 150 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 151 } 152 153 static const struct export_operations jffs2_export_ops = { 154 .get_parent = jffs2_get_parent, 155 .fh_to_dentry = jffs2_fh_to_dentry, 156 .fh_to_parent = jffs2_fh_to_parent, 157 }; 158 159 /* 160 * JFFS2 mount options. 161 * 162 * Opt_override_compr: override default compressor 163 * Opt_rp_size: size of reserved pool in KiB 164 * Opt_err: just end of array marker 165 */ 166 enum { 167 Opt_override_compr, 168 Opt_rp_size, 169 Opt_err, 170 }; 171 172 static const match_table_t tokens = { 173 {Opt_override_compr, "compr=%s"}, 174 {Opt_rp_size, "rp_size=%u"}, 175 {Opt_err, NULL}, 176 }; 177 178 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 179 { 180 substring_t args[MAX_OPT_ARGS]; 181 char *p, *name; 182 unsigned int opt; 183 184 if (!data) 185 return 0; 186 187 while ((p = strsep(&data, ","))) { 188 int token; 189 190 if (!*p) 191 continue; 192 193 token = match_token(p, tokens, args); 194 switch (token) { 195 case Opt_override_compr: 196 name = match_strdup(&args[0]); 197 198 if (!name) 199 return -ENOMEM; 200 if (!strcmp(name, "none")) 201 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 202 #ifdef CONFIG_JFFS2_LZO 203 else if (!strcmp(name, "lzo")) 204 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 205 #endif 206 #ifdef CONFIG_JFFS2_ZLIB 207 else if (!strcmp(name, "zlib")) 208 c->mount_opts.compr = 209 JFFS2_COMPR_MODE_FORCEZLIB; 210 #endif 211 else { 212 pr_err("Error: unknown compressor \"%s\"\n", 213 name); 214 kfree(name); 215 return -EINVAL; 216 } 217 kfree(name); 218 c->mount_opts.override_compr = true; 219 break; 220 case Opt_rp_size: 221 if (match_int(&args[0], &opt)) 222 return -EINVAL; 223 opt *= 1024; 224 if (opt > c->mtd->size) { 225 pr_warn("Too large reserve pool specified, max " 226 "is %llu KB\n", c->mtd->size / 1024); 227 return -EINVAL; 228 } 229 c->mount_opts.rp_size = opt; 230 break; 231 default: 232 pr_err("Error: unrecognized mount option '%s' or missing value\n", 233 p); 234 return -EINVAL; 235 } 236 } 237 238 return 0; 239 } 240 241 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 242 { 243 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 244 int err; 245 246 err = jffs2_parse_options(c, data); 247 if (err) 248 return -EINVAL; 249 250 return jffs2_do_remount_fs(sb, flags, data); 251 } 252 253 static const struct super_operations jffs2_super_operations = 254 { 255 .alloc_inode = jffs2_alloc_inode, 256 .destroy_inode =jffs2_destroy_inode, 257 .put_super = jffs2_put_super, 258 .statfs = jffs2_statfs, 259 .remount_fs = jffs2_remount_fs, 260 .evict_inode = jffs2_evict_inode, 261 .dirty_inode = jffs2_dirty_inode, 262 .show_options = jffs2_show_options, 263 .sync_fs = jffs2_sync_fs, 264 }; 265 266 /* 267 * fill in the superblock 268 */ 269 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 270 { 271 struct jffs2_sb_info *c; 272 int ret; 273 274 jffs2_dbg(1, "jffs2_get_sb_mtd():" 275 " New superblock for device %d (\"%s\")\n", 276 sb->s_mtd->index, sb->s_mtd->name); 277 278 c = kzalloc(sizeof(*c), GFP_KERNEL); 279 if (!c) 280 return -ENOMEM; 281 282 c->mtd = sb->s_mtd; 283 c->os_priv = sb; 284 sb->s_fs_info = c; 285 286 ret = jffs2_parse_options(c, data); 287 if (ret) { 288 kfree(c); 289 return -EINVAL; 290 } 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 | MS_NOATIME; 304 sb->s_xattr = jffs2_xattr_handlers; 305 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 306 sb->s_flags |= MS_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 if (jffs2_blocks_use_vmalloc(c)) 334 vfree(c->blocks); 335 else 336 kfree(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 (!(sb->s_flags & MS_RDONLY)) 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), 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