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/fs_context.h> 23 #include <linux/fs_parser.h> 24 #include <linux/jffs2.h> 25 #include <linux/pagemap.h> 26 #include <linux/mtd/super.h> 27 #include <linux/ctype.h> 28 #include <linux/namei.h> 29 #include <linux/seq_file.h> 30 #include <linux/exportfs.h> 31 #include "compr.h" 32 #include "nodelist.h" 33 34 static void jffs2_put_super(struct super_block *); 35 36 static struct kmem_cache *jffs2_inode_cachep; 37 38 static struct inode *jffs2_alloc_inode(struct super_block *sb) 39 { 40 struct jffs2_inode_info *f; 41 42 f = alloc_inode_sb(sb, jffs2_inode_cachep, GFP_KERNEL); 43 if (!f) 44 return NULL; 45 return &f->vfs_inode; 46 } 47 48 static void jffs2_free_inode(struct inode *inode) 49 { 50 struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); 51 52 kfree(f->target); 53 kmem_cache_free(jffs2_inode_cachep, f); 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 f->target = NULL; 62 inode_init_once(&f->vfs_inode); 63 } 64 65 static const char *jffs2_compr_name(unsigned int compr) 66 { 67 switch (compr) { 68 case JFFS2_COMPR_MODE_NONE: 69 return "none"; 70 #ifdef CONFIG_JFFS2_LZO 71 case JFFS2_COMPR_MODE_FORCELZO: 72 return "lzo"; 73 #endif 74 #ifdef CONFIG_JFFS2_ZLIB 75 case JFFS2_COMPR_MODE_FORCEZLIB: 76 return "zlib"; 77 #endif 78 default: 79 /* should never happen; programmer error */ 80 WARN_ON(1); 81 return ""; 82 } 83 } 84 85 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 86 { 87 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 88 struct jffs2_mount_opts *opts = &c->mount_opts; 89 90 if (opts->override_compr) 91 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 92 if (opts->set_rp_size) 93 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024); 94 95 return 0; 96 } 97 98 static int jffs2_sync_fs(struct super_block *sb, int wait) 99 { 100 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 101 102 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 103 if (jffs2_is_writebuffered(c)) 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(!d_is_dir(child)); 142 143 f = JFFS2_INODE_INFO(d_inode(child)); 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_sb, pino)); 151 } 152 153 static const struct export_operations jffs2_export_ops = { 154 .encode_fh = generic_encode_ino32_fh, 155 .get_parent = jffs2_get_parent, 156 .fh_to_dentry = jffs2_fh_to_dentry, 157 .fh_to_parent = jffs2_fh_to_parent, 158 }; 159 160 /* 161 * JFFS2 mount options. 162 * 163 * Opt_source: The source device 164 * Opt_override_compr: override default compressor 165 * Opt_rp_size: size of reserved pool in KiB 166 */ 167 enum { 168 Opt_override_compr, 169 Opt_rp_size, 170 }; 171 172 static const struct constant_table jffs2_param_compr[] = { 173 {"none", JFFS2_COMPR_MODE_NONE }, 174 #ifdef CONFIG_JFFS2_LZO 175 {"lzo", JFFS2_COMPR_MODE_FORCELZO }, 176 #endif 177 #ifdef CONFIG_JFFS2_ZLIB 178 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB }, 179 #endif 180 {} 181 }; 182 183 static const struct fs_parameter_spec jffs2_fs_parameters[] = { 184 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr), 185 fsparam_u32 ("rp_size", Opt_rp_size), 186 {} 187 }; 188 189 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param) 190 { 191 struct fs_parse_result result; 192 struct jffs2_sb_info *c = fc->s_fs_info; 193 int opt; 194 195 opt = fs_parse(fc, jffs2_fs_parameters, param, &result); 196 if (opt < 0) 197 return opt; 198 199 switch (opt) { 200 case Opt_override_compr: 201 c->mount_opts.compr = result.uint_32; 202 c->mount_opts.override_compr = true; 203 break; 204 case Opt_rp_size: 205 if (result.uint_32 > UINT_MAX / 1024) 206 return invalf(fc, "jffs2: rp_size unrepresentable"); 207 c->mount_opts.rp_size = result.uint_32 * 1024; 208 c->mount_opts.set_rp_size = true; 209 break; 210 default: 211 return -EINVAL; 212 } 213 214 return 0; 215 } 216 217 static inline void jffs2_update_mount_opts(struct fs_context *fc) 218 { 219 struct jffs2_sb_info *new_c = fc->s_fs_info; 220 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb); 221 222 mutex_lock(&c->alloc_sem); 223 if (new_c->mount_opts.override_compr) { 224 c->mount_opts.override_compr = new_c->mount_opts.override_compr; 225 c->mount_opts.compr = new_c->mount_opts.compr; 226 } 227 if (new_c->mount_opts.set_rp_size) { 228 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size; 229 c->mount_opts.rp_size = new_c->mount_opts.rp_size; 230 } 231 mutex_unlock(&c->alloc_sem); 232 } 233 234 static int jffs2_reconfigure(struct fs_context *fc) 235 { 236 struct super_block *sb = fc->root->d_sb; 237 238 sync_filesystem(sb); 239 jffs2_update_mount_opts(fc); 240 241 return jffs2_do_remount_fs(sb, fc); 242 } 243 244 static const struct super_operations jffs2_super_operations = 245 { 246 .alloc_inode = jffs2_alloc_inode, 247 .free_inode = jffs2_free_inode, 248 .put_super = jffs2_put_super, 249 .statfs = jffs2_statfs, 250 .evict_inode = jffs2_evict_inode, 251 .dirty_inode = jffs2_dirty_inode, 252 .show_options = jffs2_show_options, 253 .sync_fs = jffs2_sync_fs, 254 }; 255 256 /* 257 * fill in the superblock 258 */ 259 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc) 260 { 261 struct jffs2_sb_info *c = sb->s_fs_info; 262 263 jffs2_dbg(1, "jffs2_get_sb_mtd():" 264 " New superblock for device %d (\"%s\")\n", 265 sb->s_mtd->index, sb->s_mtd->name); 266 267 c->mtd = sb->s_mtd; 268 c->os_priv = sb; 269 270 if (c->mount_opts.rp_size > c->mtd->size) 271 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB", 272 c->mtd->size / 1024); 273 274 /* Initialize JFFS2 superblock locks, the further initialization will 275 * be done later */ 276 mutex_init(&c->alloc_sem); 277 mutex_init(&c->erase_free_sem); 278 init_waitqueue_head(&c->erase_wait); 279 init_waitqueue_head(&c->inocache_wq); 280 spin_lock_init(&c->erase_completion_lock); 281 spin_lock_init(&c->inocache_lock); 282 283 sb->s_op = &jffs2_super_operations; 284 sb->s_export_op = &jffs2_export_ops; 285 sb->s_flags = sb->s_flags | SB_NOATIME; 286 sb->s_xattr = jffs2_xattr_handlers; 287 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 288 sb->s_flags |= SB_POSIXACL; 289 #endif 290 return jffs2_do_fill_super(sb, fc); 291 } 292 293 static int jffs2_get_tree(struct fs_context *fc) 294 { 295 return get_tree_mtd(fc, jffs2_fill_super); 296 } 297 298 static void jffs2_free_fc(struct fs_context *fc) 299 { 300 kfree(fc->s_fs_info); 301 } 302 303 static const struct fs_context_operations jffs2_context_ops = { 304 .free = jffs2_free_fc, 305 .parse_param = jffs2_parse_param, 306 .get_tree = jffs2_get_tree, 307 .reconfigure = jffs2_reconfigure, 308 }; 309 310 static int jffs2_init_fs_context(struct fs_context *fc) 311 { 312 struct jffs2_sb_info *ctx; 313 314 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL); 315 if (!ctx) 316 return -ENOMEM; 317 318 fc->s_fs_info = ctx; 319 fc->ops = &jffs2_context_ops; 320 return 0; 321 } 322 323 static void jffs2_put_super (struct super_block *sb) 324 { 325 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 326 327 jffs2_dbg(2, "%s()\n", __func__); 328 329 mutex_lock(&c->alloc_sem); 330 jffs2_flush_wbuf_pad(c); 331 mutex_unlock(&c->alloc_sem); 332 333 jffs2_sum_exit(c); 334 335 jffs2_free_ino_caches(c); 336 jffs2_free_raw_node_refs(c); 337 kvfree(c->blocks); 338 jffs2_flash_cleanup(c); 339 kfree(c->inocache_list); 340 jffs2_clear_xattr_subsystem(c); 341 mtd_sync(c->mtd); 342 jffs2_dbg(1, "%s(): returning\n", __func__); 343 } 344 345 static void jffs2_kill_sb(struct super_block *sb) 346 { 347 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 348 if (c && !sb_rdonly(sb)) 349 jffs2_stop_garbage_collect_thread(c); 350 kill_mtd_super(sb); 351 kfree(c); 352 } 353 354 static struct file_system_type jffs2_fs_type = { 355 .owner = THIS_MODULE, 356 .name = "jffs2", 357 .init_fs_context = jffs2_init_fs_context, 358 .parameters = jffs2_fs_parameters, 359 .kill_sb = jffs2_kill_sb, 360 }; 361 MODULE_ALIAS_FS("jffs2"); 362 363 static int __init init_jffs2_fs(void) 364 { 365 int ret; 366 367 /* Paranoia checks for on-medium structures. If we ask GCC 368 to pack them with __attribute__((packed)) then it _also_ 369 assumes that they're not aligned -- so it emits crappy 370 code on some architectures. Ideally we want an attribute 371 which means just 'no padding', without the alignment 372 thing. But GCC doesn't have that -- we have to just 373 hope the structs are the right sizes, instead. */ 374 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 375 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 376 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 377 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 378 379 pr_info("version 2.2." 380 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 381 " (NAND)" 382 #endif 383 #ifdef CONFIG_JFFS2_SUMMARY 384 " (SUMMARY) " 385 #endif 386 " © 2001-2006 Red Hat, Inc.\n"); 387 388 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 389 sizeof(struct jffs2_inode_info), 390 0, (SLAB_RECLAIM_ACCOUNT| 391 SLAB_ACCOUNT), 392 jffs2_i_init_once); 393 if (!jffs2_inode_cachep) { 394 pr_err("error: Failed to initialise inode cache\n"); 395 return -ENOMEM; 396 } 397 ret = jffs2_compressors_init(); 398 if (ret) { 399 pr_err("error: Failed to initialise compressors\n"); 400 goto out; 401 } 402 ret = jffs2_create_slab_caches(); 403 if (ret) { 404 pr_err("error: Failed to initialise slab caches\n"); 405 goto out_compressors; 406 } 407 ret = register_filesystem(&jffs2_fs_type); 408 if (ret) { 409 pr_err("error: Failed to register filesystem\n"); 410 goto out_slab; 411 } 412 return 0; 413 414 out_slab: 415 jffs2_destroy_slab_caches(); 416 out_compressors: 417 jffs2_compressors_exit(); 418 out: 419 kmem_cache_destroy(jffs2_inode_cachep); 420 return ret; 421 } 422 423 static void __exit exit_jffs2_fs(void) 424 { 425 unregister_filesystem(&jffs2_fs_type); 426 jffs2_destroy_slab_caches(); 427 jffs2_compressors_exit(); 428 429 /* 430 * Make sure all delayed rcu free inodes are flushed before we 431 * destroy cache. 432 */ 433 rcu_barrier(); 434 kmem_cache_destroy(jffs2_inode_cachep); 435 } 436 437 module_init(init_jffs2_fs); 438 module_exit(exit_jffs2_fs); 439 440 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 441 MODULE_AUTHOR("Red Hat, Inc."); 442 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 443 // the sake of this tag. It's Free Software. 444