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_free_inode(struct inode *inode) 48 { 49 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 50 51 kfree(f->target); 52 kmem_cache_free(jffs2_inode_cachep, f); 53 } 54 55 static void jffs2_i_init_once(void *foo) 56 { 57 struct jffs2_inode_info *f = foo; 58 59 mutex_init(&f->sem); 60 inode_init_once(&f->vfs_inode); 61 } 62 63 static const char *jffs2_compr_name(unsigned int compr) 64 { 65 switch (compr) { 66 case JFFS2_COMPR_MODE_NONE: 67 return "none"; 68 #ifdef CONFIG_JFFS2_LZO 69 case JFFS2_COMPR_MODE_FORCELZO: 70 return "lzo"; 71 #endif 72 #ifdef CONFIG_JFFS2_ZLIB 73 case JFFS2_COMPR_MODE_FORCEZLIB: 74 return "zlib"; 75 #endif 76 default: 77 /* should never happen; programmer error */ 78 WARN_ON(1); 79 return ""; 80 } 81 } 82 83 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 84 { 85 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 86 struct jffs2_mount_opts *opts = &c->mount_opts; 87 88 if (opts->override_compr) 89 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 90 if (opts->rp_size) 91 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024); 92 93 return 0; 94 } 95 96 static int jffs2_sync_fs(struct super_block *sb, int wait) 97 { 98 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 99 100 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 101 if (jffs2_is_writebuffered(c)) 102 cancel_delayed_work_sync(&c->wbuf_dwork); 103 #endif 104 105 mutex_lock(&c->alloc_sem); 106 jffs2_flush_wbuf_pad(c); 107 mutex_unlock(&c->alloc_sem); 108 return 0; 109 } 110 111 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 112 uint32_t generation) 113 { 114 /* We don't care about i_generation. We'll destroy the flash 115 before we start re-using inode numbers anyway. And even 116 if that wasn't true, we'd have other problems...*/ 117 return jffs2_iget(sb, ino); 118 } 119 120 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 121 int fh_len, int fh_type) 122 { 123 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 124 jffs2_nfs_get_inode); 125 } 126 127 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 128 int fh_len, int fh_type) 129 { 130 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 131 jffs2_nfs_get_inode); 132 } 133 134 static struct dentry *jffs2_get_parent(struct dentry *child) 135 { 136 struct jffs2_inode_info *f; 137 uint32_t pino; 138 139 BUG_ON(!d_is_dir(child)); 140 141 f = JFFS2_INODE_INFO(d_inode(child)); 142 143 pino = f->inocache->pino_nlink; 144 145 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 146 f->inocache->ino, pino); 147 148 return d_obtain_alias(jffs2_iget(child->d_sb, pino)); 149 } 150 151 static const struct export_operations jffs2_export_ops = { 152 .get_parent = jffs2_get_parent, 153 .fh_to_dentry = jffs2_fh_to_dentry, 154 .fh_to_parent = jffs2_fh_to_parent, 155 }; 156 157 /* 158 * JFFS2 mount options. 159 * 160 * Opt_override_compr: override default compressor 161 * Opt_rp_size: size of reserved pool in KiB 162 * Opt_err: just end of array marker 163 */ 164 enum { 165 Opt_override_compr, 166 Opt_rp_size, 167 Opt_err, 168 }; 169 170 static const match_table_t tokens = { 171 {Opt_override_compr, "compr=%s"}, 172 {Opt_rp_size, "rp_size=%u"}, 173 {Opt_err, NULL}, 174 }; 175 176 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 177 { 178 substring_t args[MAX_OPT_ARGS]; 179 char *p, *name; 180 unsigned int opt; 181 182 if (!data) 183 return 0; 184 185 while ((p = strsep(&data, ","))) { 186 int token; 187 188 if (!*p) 189 continue; 190 191 token = match_token(p, tokens, args); 192 switch (token) { 193 case Opt_override_compr: 194 name = match_strdup(&args[0]); 195 196 if (!name) 197 return -ENOMEM; 198 if (!strcmp(name, "none")) 199 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 200 #ifdef CONFIG_JFFS2_LZO 201 else if (!strcmp(name, "lzo")) 202 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 203 #endif 204 #ifdef CONFIG_JFFS2_ZLIB 205 else if (!strcmp(name, "zlib")) 206 c->mount_opts.compr = 207 JFFS2_COMPR_MODE_FORCEZLIB; 208 #endif 209 else { 210 pr_err("Error: unknown compressor \"%s\"\n", 211 name); 212 kfree(name); 213 return -EINVAL; 214 } 215 kfree(name); 216 c->mount_opts.override_compr = true; 217 break; 218 case Opt_rp_size: 219 if (match_int(&args[0], &opt)) 220 return -EINVAL; 221 opt *= 1024; 222 if (opt > c->mtd->size) { 223 pr_warn("Too large reserve pool specified, max " 224 "is %llu KB\n", c->mtd->size / 1024); 225 return -EINVAL; 226 } 227 c->mount_opts.rp_size = opt; 228 break; 229 default: 230 pr_err("Error: unrecognized mount option '%s' or missing value\n", 231 p); 232 return -EINVAL; 233 } 234 } 235 236 return 0; 237 } 238 239 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 240 { 241 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 242 int err; 243 244 sync_filesystem(sb); 245 err = jffs2_parse_options(c, data); 246 if (err) 247 return -EINVAL; 248 249 return jffs2_do_remount_fs(sb, flags, data); 250 } 251 252 static const struct super_operations jffs2_super_operations = 253 { 254 .alloc_inode = jffs2_alloc_inode, 255 .free_inode = jffs2_free_inode, 256 .put_super = jffs2_put_super, 257 .statfs = jffs2_statfs, 258 .remount_fs = jffs2_remount_fs, 259 .evict_inode = jffs2_evict_inode, 260 .dirty_inode = jffs2_dirty_inode, 261 .show_options = jffs2_show_options, 262 .sync_fs = jffs2_sync_fs, 263 }; 264 265 /* 266 * fill in the superblock 267 */ 268 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 269 { 270 struct jffs2_sb_info *c; 271 int ret; 272 273 jffs2_dbg(1, "jffs2_get_sb_mtd():" 274 " New superblock for device %d (\"%s\")\n", 275 sb->s_mtd->index, sb->s_mtd->name); 276 277 c = kzalloc(sizeof(*c), GFP_KERNEL); 278 if (!c) 279 return -ENOMEM; 280 281 c->mtd = sb->s_mtd; 282 c->os_priv = sb; 283 sb->s_fs_info = c; 284 285 ret = jffs2_parse_options(c, data); 286 if (ret) 287 return -EINVAL; 288 289 /* Initialize JFFS2 superblock locks, the further initialization will 290 * be done later */ 291 mutex_init(&c->alloc_sem); 292 mutex_init(&c->erase_free_sem); 293 init_waitqueue_head(&c->erase_wait); 294 init_waitqueue_head(&c->inocache_wq); 295 spin_lock_init(&c->erase_completion_lock); 296 spin_lock_init(&c->inocache_lock); 297 298 sb->s_op = &jffs2_super_operations; 299 sb->s_export_op = &jffs2_export_ops; 300 sb->s_flags = sb->s_flags | SB_NOATIME; 301 sb->s_xattr = jffs2_xattr_handlers; 302 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 303 sb->s_flags |= SB_POSIXACL; 304 #endif 305 ret = jffs2_do_fill_super(sb, data, silent); 306 return ret; 307 } 308 309 static struct dentry *jffs2_mount(struct file_system_type *fs_type, 310 int flags, const char *dev_name, 311 void *data) 312 { 313 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); 314 } 315 316 static void jffs2_put_super (struct super_block *sb) 317 { 318 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 319 320 jffs2_dbg(2, "%s()\n", __func__); 321 322 mutex_lock(&c->alloc_sem); 323 jffs2_flush_wbuf_pad(c); 324 mutex_unlock(&c->alloc_sem); 325 326 jffs2_sum_exit(c); 327 328 jffs2_free_ino_caches(c); 329 jffs2_free_raw_node_refs(c); 330 kvfree(c->blocks); 331 jffs2_flash_cleanup(c); 332 kfree(c->inocache_list); 333 jffs2_clear_xattr_subsystem(c); 334 mtd_sync(c->mtd); 335 jffs2_dbg(1, "%s(): returning\n", __func__); 336 } 337 338 static void jffs2_kill_sb(struct super_block *sb) 339 { 340 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 341 if (c && !sb_rdonly(sb)) 342 jffs2_stop_garbage_collect_thread(c); 343 kill_mtd_super(sb); 344 kfree(c); 345 } 346 347 static struct file_system_type jffs2_fs_type = { 348 .owner = THIS_MODULE, 349 .name = "jffs2", 350 .mount = jffs2_mount, 351 .kill_sb = jffs2_kill_sb, 352 }; 353 MODULE_ALIAS_FS("jffs2"); 354 355 static int __init init_jffs2_fs(void) 356 { 357 int ret; 358 359 /* Paranoia checks for on-medium structures. If we ask GCC 360 to pack them with __attribute__((packed)) then it _also_ 361 assumes that they're not aligned -- so it emits crappy 362 code on some architectures. Ideally we want an attribute 363 which means just 'no padding', without the alignment 364 thing. But GCC doesn't have that -- we have to just 365 hope the structs are the right sizes, instead. */ 366 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 367 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 368 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 369 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 370 371 pr_info("version 2.2." 372 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 373 " (NAND)" 374 #endif 375 #ifdef CONFIG_JFFS2_SUMMARY 376 " (SUMMARY) " 377 #endif 378 " © 2001-2006 Red Hat, Inc.\n"); 379 380 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 381 sizeof(struct jffs2_inode_info), 382 0, (SLAB_RECLAIM_ACCOUNT| 383 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 384 jffs2_i_init_once); 385 if (!jffs2_inode_cachep) { 386 pr_err("error: Failed to initialise inode cache\n"); 387 return -ENOMEM; 388 } 389 ret = jffs2_compressors_init(); 390 if (ret) { 391 pr_err("error: Failed to initialise compressors\n"); 392 goto out; 393 } 394 ret = jffs2_create_slab_caches(); 395 if (ret) { 396 pr_err("error: Failed to initialise slab caches\n"); 397 goto out_compressors; 398 } 399 ret = register_filesystem(&jffs2_fs_type); 400 if (ret) { 401 pr_err("error: Failed to register filesystem\n"); 402 goto out_slab; 403 } 404 return 0; 405 406 out_slab: 407 jffs2_destroy_slab_caches(); 408 out_compressors: 409 jffs2_compressors_exit(); 410 out: 411 kmem_cache_destroy(jffs2_inode_cachep); 412 return ret; 413 } 414 415 static void __exit exit_jffs2_fs(void) 416 { 417 unregister_filesystem(&jffs2_fs_type); 418 jffs2_destroy_slab_caches(); 419 jffs2_compressors_exit(); 420 421 /* 422 * Make sure all delayed rcu free inodes are flushed before we 423 * destroy cache. 424 */ 425 rcu_barrier(); 426 kmem_cache_destroy(jffs2_inode_cachep); 427 } 428 429 module_init(init_jffs2_fs); 430 module_exit(exit_jffs2_fs); 431 432 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 433 MODULE_AUTHOR("Red Hat, Inc."); 434 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 435 // the sake of this tag. It's Free Software. 436