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 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/init.h> 16 #include <linux/list.h> 17 #include <linux/fs.h> 18 #include <linux/err.h> 19 #include <linux/mount.h> 20 #include <linux/parser.h> 21 #include <linux/jffs2.h> 22 #include <linux/pagemap.h> 23 #include <linux/mtd/super.h> 24 #include <linux/ctype.h> 25 #include <linux/namei.h> 26 #include <linux/seq_file.h> 27 #include <linux/exportfs.h> 28 #include "compr.h" 29 #include "nodelist.h" 30 31 static void jffs2_put_super(struct super_block *); 32 33 static struct kmem_cache *jffs2_inode_cachep; 34 35 static struct inode *jffs2_alloc_inode(struct super_block *sb) 36 { 37 struct jffs2_inode_info *f; 38 39 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 40 if (!f) 41 return NULL; 42 return &f->vfs_inode; 43 } 44 45 static void jffs2_i_callback(struct rcu_head *head) 46 { 47 struct inode *inode = container_of(head, struct inode, i_rcu); 48 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 49 } 50 51 static void jffs2_destroy_inode(struct inode *inode) 52 { 53 call_rcu(&inode->i_rcu, jffs2_i_callback); 54 } 55 56 static void jffs2_i_init_once(void *foo) 57 { 58 struct jffs2_inode_info *f = foo; 59 60 mutex_init(&f->sem); 61 inode_init_once(&f->vfs_inode); 62 } 63 64 static void jffs2_write_super(struct super_block *sb) 65 { 66 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 67 68 lock_super(sb); 69 sb->s_dirt = 0; 70 71 if (!(sb->s_flags & MS_RDONLY)) { 72 D1(printk(KERN_DEBUG "jffs2_write_super()\n")); 73 jffs2_flush_wbuf_gc(c, 0); 74 } 75 76 unlock_super(sb); 77 } 78 79 static const char *jffs2_compr_name(unsigned int compr) 80 { 81 switch (compr) { 82 case JFFS2_COMPR_MODE_NONE: 83 return "none"; 84 #ifdef CONFIG_JFFS2_LZO 85 case JFFS2_COMPR_MODE_FORCELZO: 86 return "lzo"; 87 #endif 88 #ifdef CONFIG_JFFS2_ZLIB 89 case JFFS2_COMPR_MODE_FORCEZLIB: 90 return "zlib"; 91 #endif 92 default: 93 /* should never happen; programmer error */ 94 WARN_ON(1); 95 return ""; 96 } 97 } 98 99 static int jffs2_show_options(struct seq_file *s, struct vfsmount *mnt) 100 { 101 struct jffs2_sb_info *c = JFFS2_SB_INFO(mnt->mnt_sb); 102 struct jffs2_mount_opts *opts = &c->mount_opts; 103 104 if (opts->override_compr) 105 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 106 107 return 0; 108 } 109 110 static int jffs2_sync_fs(struct super_block *sb, int wait) 111 { 112 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 113 114 jffs2_write_super(sb); 115 116 mutex_lock(&c->alloc_sem); 117 jffs2_flush_wbuf_pad(c); 118 mutex_unlock(&c->alloc_sem); 119 return 0; 120 } 121 122 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 123 uint32_t generation) 124 { 125 /* We don't care about i_generation. We'll destroy the flash 126 before we start re-using inode numbers anyway. And even 127 if that wasn't true, we'd have other problems...*/ 128 return jffs2_iget(sb, ino); 129 } 130 131 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 132 int fh_len, int fh_type) 133 { 134 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 135 jffs2_nfs_get_inode); 136 } 137 138 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 139 int fh_len, int fh_type) 140 { 141 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 142 jffs2_nfs_get_inode); 143 } 144 145 static struct dentry *jffs2_get_parent(struct dentry *child) 146 { 147 struct jffs2_inode_info *f; 148 uint32_t pino; 149 150 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 151 152 f = JFFS2_INODE_INFO(child->d_inode); 153 154 pino = f->inocache->pino_nlink; 155 156 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 157 f->inocache->ino, pino); 158 159 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 160 } 161 162 static const struct export_operations jffs2_export_ops = { 163 .get_parent = jffs2_get_parent, 164 .fh_to_dentry = jffs2_fh_to_dentry, 165 .fh_to_parent = jffs2_fh_to_parent, 166 }; 167 168 /* 169 * JFFS2 mount options. 170 * 171 * Opt_override_compr: override default compressor 172 * Opt_err: just end of array marker 173 */ 174 enum { 175 Opt_override_compr, 176 Opt_err, 177 }; 178 179 static const match_table_t tokens = { 180 {Opt_override_compr, "compr=%s"}, 181 {Opt_err, NULL}, 182 }; 183 184 static int jffs2_parse_options(struct jffs2_sb_info *c, char *data) 185 { 186 substring_t args[MAX_OPT_ARGS]; 187 char *p, *name; 188 189 if (!data) 190 return 0; 191 192 while ((p = strsep(&data, ","))) { 193 int token; 194 195 if (!*p) 196 continue; 197 198 token = match_token(p, tokens, args); 199 switch (token) { 200 case Opt_override_compr: 201 name = match_strdup(&args[0]); 202 203 if (!name) 204 return -ENOMEM; 205 if (!strcmp(name, "none")) 206 c->mount_opts.compr = JFFS2_COMPR_MODE_NONE; 207 #ifdef CONFIG_JFFS2_LZO 208 else if (!strcmp(name, "lzo")) 209 c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO; 210 #endif 211 #ifdef CONFIG_JFFS2_ZLIB 212 else if (!strcmp(name, "zlib")) 213 c->mount_opts.compr = 214 JFFS2_COMPR_MODE_FORCEZLIB; 215 #endif 216 else { 217 printk(KERN_ERR "JFFS2 Error: unknown compressor \"%s\"", 218 name); 219 kfree(name); 220 return -EINVAL; 221 } 222 kfree(name); 223 c->mount_opts.override_compr = true; 224 break; 225 default: 226 printk(KERN_ERR "JFFS2 Error: unrecognized mount option '%s' or missing value\n", 227 p); 228 return -EINVAL; 229 } 230 } 231 232 return 0; 233 } 234 235 static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data) 236 { 237 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 238 int err; 239 240 err = jffs2_parse_options(c, data); 241 if (err) 242 return -EINVAL; 243 244 return jffs2_do_remount_fs(sb, flags, data); 245 } 246 247 static const struct super_operations jffs2_super_operations = 248 { 249 .alloc_inode = jffs2_alloc_inode, 250 .destroy_inode =jffs2_destroy_inode, 251 .put_super = jffs2_put_super, 252 .write_super = jffs2_write_super, 253 .statfs = jffs2_statfs, 254 .remount_fs = jffs2_remount_fs, 255 .evict_inode = jffs2_evict_inode, 256 .dirty_inode = jffs2_dirty_inode, 257 .show_options = jffs2_show_options, 258 .sync_fs = jffs2_sync_fs, 259 }; 260 261 /* 262 * fill in the superblock 263 */ 264 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 265 { 266 struct jffs2_sb_info *c; 267 int ret; 268 269 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" 270 " New superblock for device %d (\"%s\")\n", 271 sb->s_mtd->index, sb->s_mtd->name)); 272 273 c = kzalloc(sizeof(*c), GFP_KERNEL); 274 if (!c) 275 return -ENOMEM; 276 277 c->mtd = sb->s_mtd; 278 c->os_priv = sb; 279 sb->s_fs_info = c; 280 281 ret = jffs2_parse_options(c, data); 282 if (ret) { 283 kfree(c); 284 return -EINVAL; 285 } 286 287 /* Initialize JFFS2 superblock locks, the further initialization will 288 * be done later */ 289 mutex_init(&c->alloc_sem); 290 mutex_init(&c->erase_free_sem); 291 init_waitqueue_head(&c->erase_wait); 292 init_waitqueue_head(&c->inocache_wq); 293 spin_lock_init(&c->erase_completion_lock); 294 spin_lock_init(&c->inocache_lock); 295 296 sb->s_op = &jffs2_super_operations; 297 sb->s_export_op = &jffs2_export_ops; 298 sb->s_flags = sb->s_flags | MS_NOATIME; 299 sb->s_xattr = jffs2_xattr_handlers; 300 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 301 sb->s_flags |= MS_POSIXACL; 302 #endif 303 ret = jffs2_do_fill_super(sb, data, silent); 304 return ret; 305 } 306 307 static struct dentry *jffs2_mount(struct file_system_type *fs_type, 308 int flags, const char *dev_name, 309 void *data) 310 { 311 return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super); 312 } 313 314 static void jffs2_put_super (struct super_block *sb) 315 { 316 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 317 318 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 319 320 if (sb->s_dirt) 321 jffs2_write_super(sb); 322 323 mutex_lock(&c->alloc_sem); 324 jffs2_flush_wbuf_pad(c); 325 mutex_unlock(&c->alloc_sem); 326 327 jffs2_sum_exit(c); 328 329 jffs2_free_ino_caches(c); 330 jffs2_free_raw_node_refs(c); 331 if (jffs2_blocks_use_vmalloc(c)) 332 vfree(c->blocks); 333 else 334 kfree(c->blocks); 335 jffs2_flash_cleanup(c); 336 kfree(c->inocache_list); 337 jffs2_clear_xattr_subsystem(c); 338 if (c->mtd->sync) 339 c->mtd->sync(c->mtd); 340 341 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 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 printk(KERN_INFO "JFFS2 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 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 392 return -ENOMEM; 393 } 394 ret = jffs2_compressors_init(); 395 if (ret) { 396 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 397 goto out; 398 } 399 ret = jffs2_create_slab_caches(); 400 if (ret) { 401 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 402 goto out_compressors; 403 } 404 ret = register_filesystem(&jffs2_fs_type); 405 if (ret) { 406 printk(KERN_ERR "JFFS2 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