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 void jffs2_write_super(struct super_block *sb) 67 { 68 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 69 70 lock_super(sb); 71 sb->s_dirt = 0; 72 73 if (!(sb->s_flags & MS_RDONLY)) { 74 jffs2_dbg(1, "%s()\n", __func__); 75 jffs2_flush_wbuf_gc(c, 0); 76 } 77 78 unlock_super(sb); 79 } 80 81 static const char *jffs2_compr_name(unsigned int compr) 82 { 83 switch (compr) { 84 case JFFS2_COMPR_MODE_NONE: 85 return "none"; 86 #ifdef CONFIG_JFFS2_LZO 87 case JFFS2_COMPR_MODE_FORCELZO: 88 return "lzo"; 89 #endif 90 #ifdef CONFIG_JFFS2_ZLIB 91 case JFFS2_COMPR_MODE_FORCEZLIB: 92 return "zlib"; 93 #endif 94 default: 95 /* should never happen; programmer error */ 96 WARN_ON(1); 97 return ""; 98 } 99 } 100 101 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 102 { 103 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 104 struct jffs2_mount_opts *opts = &c->mount_opts; 105 106 if (opts->override_compr) 107 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 108 109 return 0; 110 } 111 112 static int jffs2_sync_fs(struct super_block *sb, int wait) 113 { 114 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 115 116 jffs2_write_super(sb); 117 118 mutex_lock(&c->alloc_sem); 119 jffs2_flush_wbuf_pad(c); 120 mutex_unlock(&c->alloc_sem); 121 return 0; 122 } 123 124 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 125 uint32_t generation) 126 { 127 /* We don't care about i_generation. We'll destroy the flash 128 before we start re-using inode numbers anyway. And even 129 if that wasn't true, we'd have other problems...*/ 130 return jffs2_iget(sb, ino); 131 } 132 133 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 134 int fh_len, int fh_type) 135 { 136 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 137 jffs2_nfs_get_inode); 138 } 139 140 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 141 int fh_len, int fh_type) 142 { 143 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 144 jffs2_nfs_get_inode); 145 } 146 147 static struct dentry *jffs2_get_parent(struct dentry *child) 148 { 149 struct jffs2_inode_info *f; 150 uint32_t pino; 151 152 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 153 154 f = JFFS2_INODE_INFO(child->d_inode); 155 156 pino = f->inocache->pino_nlink; 157 158 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 159 f->inocache->ino, pino); 160 161 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 162 } 163 164 static const struct export_operations jffs2_export_ops = { 165 .get_parent = jffs2_get_parent, 166 .fh_to_dentry = jffs2_fh_to_dentry, 167 .fh_to_parent = jffs2_fh_to_parent, 168 }; 169 170 /* 171 * JFFS2 mount options. 172 * 173 * Opt_override_compr: override default compressor 174 * Opt_err: just end of array marker 175 */ 176 enum { 177 Opt_override_compr, 178 Opt_err, 179 }; 180 181 static const match_table_t tokens = { 182 {Opt_override_compr, "compr=%s"}, 183 {Opt_err, NULL}, 184 }; 185 186 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 187 { 188 substring_t args[MAX_OPT_ARGS]; 189 char *p, *name; 190 191 if (!data) 192 return 0; 193 194 while ((p = strsep(&data, ","))) { 195 int token; 196 197 if (!*p) 198 continue; 199 200 token = match_token(p, tokens, args); 201 switch (token) { 202 case Opt_override_compr: 203 name = match_strdup(&args[0]); 204 205 if (!name) 206 return -ENOMEM; 207 if (!strcmp(name, "none")) 208 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 209 #ifdef CONFIG_JFFS2_LZO 210 else if (!strcmp(name, "lzo")) 211 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 212 #endif 213 #ifdef CONFIG_JFFS2_ZLIB 214 else if (!strcmp(name, "zlib")) 215 c->mount_opts.compr = 216 JFFS2_COMPR_MODE_FORCEZLIB; 217 #endif 218 else { 219 pr_err("Error: unknown compressor \"%s\"\n", 220 name); 221 kfree(name); 222 return -EINVAL; 223 } 224 kfree(name); 225 c->mount_opts.override_compr = true; 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 .write_super = jffs2_write_super, 255 .statfs = jffs2_statfs, 256 .remount_fs = jffs2_remount_fs, 257 .evict_inode = jffs2_evict_inode, 258 .dirty_inode = jffs2_dirty_inode, 259 .show_options = jffs2_show_options, 260 .sync_fs = jffs2_sync_fs, 261 }; 262 263 /* 264 * fill in the superblock 265 */ 266 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 267 { 268 struct jffs2_sb_info *c; 269 int ret; 270 271 jffs2_dbg(1, "jffs2_get_sb_mtd():" 272 " New superblock for device %d (\"%s\")\n", 273 sb->s_mtd->index, sb->s_mtd->name); 274 275 c = kzalloc(sizeof(*c), GFP_KERNEL); 276 if (!c) 277 return -ENOMEM; 278 279 c->mtd = sb->s_mtd; 280 c->os_priv = sb; 281 sb->s_fs_info = c; 282 283 ret = jffs2_parse_options(c, data); 284 if (ret) { 285 kfree(c); 286 return -EINVAL; 287 } 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 | MS_NOATIME; 301 sb->s_xattr = jffs2_xattr_handlers; 302 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 303 sb->s_flags |= MS_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 if (sb->s_dirt) 323 jffs2_write_super(sb); 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 }; 359 360 static int __init init_jffs2_fs(void) 361 { 362 int ret; 363 364 /* Paranoia checks for on-medium structures. If we ask GCC 365 to pack them with __attribute__((packed)) then it _also_ 366 assumes that they're not aligned -- so it emits crappy 367 code on some architectures. Ideally we want an attribute 368 which means just 'no padding', without the alignment 369 thing. But GCC doesn't have that -- we have to just 370 hope the structs are the right sizes, instead. */ 371 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 372 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 373 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 374 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 375 376 pr_info("version 2.2." 377 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 378 " (NAND)" 379 #endif 380 #ifdef CONFIG_JFFS2_SUMMARY 381 " (SUMMARY) " 382 #endif 383 " © 2001-2006 Red Hat, Inc.\n"); 384 385 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 386 sizeof(struct jffs2_inode_info), 387 0, (SLAB_RECLAIM_ACCOUNT| 388 SLAB_MEM_SPREAD), 389 jffs2_i_init_once); 390 if (!jffs2_inode_cachep) { 391 pr_err("error: Failed to initialise inode cache\n"); 392 return -ENOMEM; 393 } 394 ret = jffs2_compressors_init(); 395 if (ret) { 396 pr_err("error: Failed to initialise compressors\n"); 397 goto out; 398 } 399 ret = jffs2_create_slab_caches(); 400 if (ret) { 401 pr_err("error: Failed to initialise slab caches\n"); 402 goto out_compressors; 403 } 404 ret = register_filesystem(&jffs2_fs_type); 405 if (ret) { 406 pr_err("error: Failed to register filesystem\n"); 407 goto out_slab; 408 } 409 return 0; 410 411 out_slab: 412 jffs2_destroy_slab_caches(); 413 out_compressors: 414 jffs2_compressors_exit(); 415 out: 416 kmem_cache_destroy(jffs2_inode_cachep); 417 return ret; 418 } 419 420 static void __exit exit_jffs2_fs(void) 421 { 422 unregister_filesystem(&jffs2_fs_type); 423 jffs2_destroy_slab_caches(); 424 jffs2_compressors_exit(); 425 kmem_cache_destroy(jffs2_inode_cachep); 426 } 427 428 module_init(init_jffs2_fs); 429 module_exit(exit_jffs2_fs); 430 431 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 432 MODULE_AUTHOR("Red Hat, Inc."); 433 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 434 // the sake of this tag. It's Free Software. 435