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 mutex_lock(&c->alloc_sem); 104 jffs2_flush_wbuf_pad(c); 105 mutex_unlock(&c->alloc_sem); 106 return 0; 107 } 108 109 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 110 uint32_t generation) 111 { 112 /* We don't care about i_generation. We'll destroy the flash 113 before we start re-using inode numbers anyway. And even 114 if that wasn't true, we'd have other problems...*/ 115 return jffs2_iget(sb, ino); 116 } 117 118 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 119 int fh_len, int fh_type) 120 { 121 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 122 jffs2_nfs_get_inode); 123 } 124 125 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 126 int fh_len, int fh_type) 127 { 128 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 129 jffs2_nfs_get_inode); 130 } 131 132 static struct dentry *jffs2_get_parent(struct dentry *child) 133 { 134 struct jffs2_inode_info *f; 135 uint32_t pino; 136 137 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 138 139 f = JFFS2_INODE_INFO(child->d_inode); 140 141 pino = f->inocache->pino_nlink; 142 143 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 144 f->inocache->ino, pino); 145 146 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 147 } 148 149 static const struct export_operations jffs2_export_ops = { 150 .get_parent = jffs2_get_parent, 151 .fh_to_dentry = jffs2_fh_to_dentry, 152 .fh_to_parent = jffs2_fh_to_parent, 153 }; 154 155 /* 156 * JFFS2 mount options. 157 * 158 * Opt_override_compr: override default compressor 159 * Opt_rp_size: size of reserved pool in KiB 160 * Opt_err: just end of array marker 161 */ 162 enum { 163 Opt_override_compr, 164 Opt_rp_size, 165 Opt_err, 166 }; 167 168 static const match_table_t tokens = { 169 {Opt_override_compr, "compr=%s"}, 170 {Opt_rp_size, "rp_size=%u"}, 171 {Opt_err, NULL}, 172 }; 173 174 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 175 { 176 substring_t args[MAX_OPT_ARGS]; 177 char *p, *name; 178 unsigned int opt; 179 180 if (!data) 181 return 0; 182 183 while ((p = strsep(&data, ","))) { 184 int token; 185 186 if (!*p) 187 continue; 188 189 token = match_token(p, tokens, args); 190 switch (token) { 191 case Opt_override_compr: 192 name = match_strdup(&args[0]); 193 194 if (!name) 195 return -ENOMEM; 196 if (!strcmp(name, "none")) 197 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 198 #ifdef CONFIG_JFFS2_LZO 199 else if (!strcmp(name, "lzo")) 200 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 201 #endif 202 #ifdef CONFIG_JFFS2_ZLIB 203 else if (!strcmp(name, "zlib")) 204 c->mount_opts.compr = 205 JFFS2_COMPR_MODE_FORCEZLIB; 206 #endif 207 else { 208 pr_err("Error: unknown compressor \"%s\"\n", 209 name); 210 kfree(name); 211 return -EINVAL; 212 } 213 kfree(name); 214 c->mount_opts.override_compr = true; 215 break; 216 case Opt_rp_size: 217 if (match_int(&args[0], &opt)) 218 return -EINVAL; 219 opt *= 1024; 220 if (opt > c->mtd->size) { 221 pr_warn("Too large reserve pool specified, max " 222 "is %llu KB\n", c->mtd->size / 1024); 223 return -EINVAL; 224 } 225 c->mount_opts.rp_size = opt; 226 break; 227 default: 228 pr_err("Error: unrecognized mount option '%s' or missing value\n", 229 p); 230 return -EINVAL; 231 } 232 } 233 234 return 0; 235 } 236 237 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 238 { 239 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 240 int err; 241 242 err = jffs2_parse_options(c, data); 243 if (err) 244 return -EINVAL; 245 246 return jffs2_do_remount_fs(sb, flags, data); 247 } 248 249 static const struct super_operations jffs2_super_operations = 250 { 251 .alloc_inode = jffs2_alloc_inode, 252 .destroy_inode =jffs2_destroy_inode, 253 .put_super = jffs2_put_super, 254 .statfs = jffs2_statfs, 255 .remount_fs = jffs2_remount_fs, 256 .evict_inode = jffs2_evict_inode, 257 .dirty_inode = jffs2_dirty_inode, 258 .show_options = jffs2_show_options, 259 .sync_fs = jffs2_sync_fs, 260 }; 261 262 /* 263 * fill in the superblock 264 */ 265 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 266 { 267 struct jffs2_sb_info *c; 268 int ret; 269 270 jffs2_dbg(1, "jffs2_get_sb_mtd():" 271 " New superblock for device %d (\"%s\")\n", 272 sb->s_mtd->index, sb->s_mtd->name); 273 274 c = kzalloc(sizeof(*c), GFP_KERNEL); 275 if (!c) 276 return -ENOMEM; 277 278 c->mtd = sb->s_mtd; 279 c->os_priv = sb; 280 sb->s_fs_info = c; 281 282 ret = jffs2_parse_options(c, data); 283 if (ret) { 284 kfree(c); 285 return -EINVAL; 286 } 287 288 /* Initialize JFFS2 superblock locks, the further initialization will 289 * be done later */ 290 mutex_init(&c->alloc_sem); 291 mutex_init(&c->erase_free_sem); 292 init_waitqueue_head(&c->erase_wait); 293 init_waitqueue_head(&c->inocache_wq); 294 spin_lock_init(&c->erase_completion_lock); 295 spin_lock_init(&c->inocache_lock); 296 297 sb->s_op = &jffs2_super_operations; 298 sb->s_export_op = &jffs2_export_ops; 299 sb->s_flags = sb->s_flags | MS_NOATIME; 300 sb->s_xattr = jffs2_xattr_handlers; 301 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 302 sb->s_flags |= MS_POSIXACL; 303 #endif 304 ret = jffs2_do_fill_super(sb, data, silent); 305 return ret; 306 } 307 308 static struct dentry *jffs2_mount(struct file_system_type *fs_type, 309 int flags, const char *dev_name, 310 void *data) 311 { 312 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); 313 } 314 315 static void jffs2_put_super (struct super_block *sb) 316 { 317 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 318 319 jffs2_dbg(2, "%s()\n", __func__); 320 321 mutex_lock(&c->alloc_sem); 322 jffs2_flush_wbuf_pad(c); 323 mutex_unlock(&c->alloc_sem); 324 325 jffs2_sum_exit(c); 326 327 jffs2_free_ino_caches(c); 328 jffs2_free_raw_node_refs(c); 329 if (jffs2_blocks_use_vmalloc(c)) 330 vfree(c->blocks); 331 else 332 kfree(c->blocks); 333 jffs2_flash_cleanup(c); 334 kfree(c->inocache_list); 335 jffs2_clear_xattr_subsystem(c); 336 mtd_sync(c->mtd); 337 jffs2_dbg(1, "%s(): returning\n", __func__); 338 } 339 340 static void jffs2_kill_sb(struct super_block *sb) 341 { 342 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 343 if (!(sb->s_flags & MS_RDONLY)) 344 jffs2_stop_garbage_collect_thread(c); 345 kill_mtd_super(sb); 346 kfree(c); 347 } 348 349 static struct file_system_type jffs2_fs_type = { 350 .owner = THIS_MODULE, 351 .name = "jffs2", 352 .mount = jffs2_mount, 353 .kill_sb = jffs2_kill_sb, 354 }; 355 356 static int __init init_jffs2_fs(void) 357 { 358 int ret; 359 360 /* Paranoia checks for on-medium structures. If we ask GCC 361 to pack them with __attribute__((packed)) then it _also_ 362 assumes that they're not aligned -- so it emits crappy 363 code on some architectures. Ideally we want an attribute 364 which means just 'no padding', without the alignment 365 thing. But GCC doesn't have that -- we have to just 366 hope the structs are the right sizes, instead. */ 367 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 368 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 369 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 370 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 371 372 pr_info("version 2.2." 373 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 374 " (NAND)" 375 #endif 376 #ifdef CONFIG_JFFS2_SUMMARY 377 " (SUMMARY) " 378 #endif 379 " © 2001-2006 Red Hat, Inc.\n"); 380 381 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 382 sizeof(struct jffs2_inode_info), 383 0, (SLAB_RECLAIM_ACCOUNT| 384 SLAB_MEM_SPREAD), 385 jffs2_i_init_once); 386 if (!jffs2_inode_cachep) { 387 pr_err("error: Failed to initialise inode cache\n"); 388 return -ENOMEM; 389 } 390 ret = jffs2_compressors_init(); 391 if (ret) { 392 pr_err("error: Failed to initialise compressors\n"); 393 goto out; 394 } 395 ret = jffs2_create_slab_caches(); 396 if (ret) { 397 pr_err("error: Failed to initialise slab caches\n"); 398 goto out_compressors; 399 } 400 ret = register_filesystem(&jffs2_fs_type); 401 if (ret) { 402 pr_err("error: Failed to register filesystem\n"); 403 goto out_slab; 404 } 405 return 0; 406 407 out_slab: 408 jffs2_destroy_slab_caches(); 409 out_compressors: 410 jffs2_compressors_exit(); 411 out: 412 kmem_cache_destroy(jffs2_inode_cachep); 413 return ret; 414 } 415 416 static void __exit exit_jffs2_fs(void) 417 { 418 unregister_filesystem(&jffs2_fs_type); 419 jffs2_destroy_slab_caches(); 420 jffs2_compressors_exit(); 421 kmem_cache_destroy(jffs2_inode_cachep); 422 } 423 424 module_init(init_jffs2_fs); 425 module_exit(exit_jffs2_fs); 426 427 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 428 MODULE_AUTHOR("Red Hat, Inc."); 429 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 430 // the sake of this tag. It's Free Software. 431