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 inode_init_once(&f->vfs_inode); 62 } 63 64 static const char *jffs2_compr_name(unsigned int compr) 65 { 66 switch (compr) { 67 case JFFS2_COMPR_MODE_NONE: 68 return "none"; 69 #ifdef CONFIG_JFFS2_LZO 70 case JFFS2_COMPR_MODE_FORCELZO: 71 return "lzo"; 72 #endif 73 #ifdef CONFIG_JFFS2_ZLIB 74 case JFFS2_COMPR_MODE_FORCEZLIB: 75 return "zlib"; 76 #endif 77 default: 78 /* should never happen; programmer error */ 79 WARN_ON(1); 80 return ""; 81 } 82 } 83 84 static int jffs2_show_options(struct seq_file *s, struct dentry *root) 85 { 86 struct jffs2_sb_info *c = JFFS2_SB_INFO(root->d_sb); 87 struct jffs2_mount_opts *opts = &c->mount_opts; 88 89 if (opts->override_compr) 90 seq_printf(s, ",compr=%s", jffs2_compr_name(opts->compr)); 91 if (opts->set_rp_size) 92 seq_printf(s, ",rp_size=%u", opts->rp_size / 1024); 93 94 return 0; 95 } 96 97 static int jffs2_sync_fs(struct super_block *sb, int wait) 98 { 99 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 100 101 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 102 if (jffs2_is_writebuffered(c)) 103 cancel_delayed_work_sync(&c->wbuf_dwork); 104 #endif 105 106 mutex_lock(&c->alloc_sem); 107 jffs2_flush_wbuf_pad(c); 108 mutex_unlock(&c->alloc_sem); 109 return 0; 110 } 111 112 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 113 uint32_t generation) 114 { 115 /* We don't care about i_generation. We'll destroy the flash 116 before we start re-using inode numbers anyway. And even 117 if that wasn't true, we'd have other problems...*/ 118 return jffs2_iget(sb, ino); 119 } 120 121 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 122 int fh_len, int fh_type) 123 { 124 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 125 jffs2_nfs_get_inode); 126 } 127 128 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 129 int fh_len, int fh_type) 130 { 131 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 132 jffs2_nfs_get_inode); 133 } 134 135 static struct dentry *jffs2_get_parent(struct dentry *child) 136 { 137 struct jffs2_inode_info *f; 138 uint32_t pino; 139 140 BUG_ON(!d_is_dir(child)); 141 142 f = JFFS2_INODE_INFO(d_inode(child)); 143 144 pino = f->inocache->pino_nlink; 145 146 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 147 f->inocache->ino, pino); 148 149 return d_obtain_alias(jffs2_iget(child->d_sb, pino)); 150 } 151 152 static const struct export_operations jffs2_export_ops = { 153 .encode_fh = generic_encode_ino32_fh, 154 .get_parent = jffs2_get_parent, 155 .fh_to_dentry = jffs2_fh_to_dentry, 156 .fh_to_parent = jffs2_fh_to_parent, 157 }; 158 159 /* 160 * JFFS2 mount options. 161 * 162 * Opt_source: The source device 163 * Opt_override_compr: override default compressor 164 * Opt_rp_size: size of reserved pool in KiB 165 */ 166 enum { 167 Opt_override_compr, 168 Opt_rp_size, 169 }; 170 171 static const struct constant_table jffs2_param_compr[] = { 172 {"none", JFFS2_COMPR_MODE_NONE }, 173 #ifdef CONFIG_JFFS2_LZO 174 {"lzo", JFFS2_COMPR_MODE_FORCELZO }, 175 #endif 176 #ifdef CONFIG_JFFS2_ZLIB 177 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB }, 178 #endif 179 {} 180 }; 181 182 static const struct fs_parameter_spec jffs2_fs_parameters[] = { 183 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr), 184 fsparam_u32 ("rp_size", Opt_rp_size), 185 {} 186 }; 187 188 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param) 189 { 190 struct fs_parse_result result; 191 struct jffs2_sb_info *c = fc->s_fs_info; 192 int opt; 193 194 opt = fs_parse(fc, jffs2_fs_parameters, param, &result); 195 if (opt < 0) 196 return opt; 197 198 switch (opt) { 199 case Opt_override_compr: 200 c->mount_opts.compr = result.uint_32; 201 c->mount_opts.override_compr = true; 202 break; 203 case Opt_rp_size: 204 if (result.uint_32 > UINT_MAX / 1024) 205 return invalf(fc, "jffs2: rp_size unrepresentable"); 206 c->mount_opts.rp_size = result.uint_32 * 1024; 207 c->mount_opts.set_rp_size = true; 208 break; 209 default: 210 return -EINVAL; 211 } 212 213 return 0; 214 } 215 216 static inline void jffs2_update_mount_opts(struct fs_context *fc) 217 { 218 struct jffs2_sb_info *new_c = fc->s_fs_info; 219 struct jffs2_sb_info *c = JFFS2_SB_INFO(fc->root->d_sb); 220 221 mutex_lock(&c->alloc_sem); 222 if (new_c->mount_opts.override_compr) { 223 c->mount_opts.override_compr = new_c->mount_opts.override_compr; 224 c->mount_opts.compr = new_c->mount_opts.compr; 225 } 226 if (new_c->mount_opts.set_rp_size) { 227 c->mount_opts.set_rp_size = new_c->mount_opts.set_rp_size; 228 c->mount_opts.rp_size = new_c->mount_opts.rp_size; 229 } 230 mutex_unlock(&c->alloc_sem); 231 } 232 233 static int jffs2_reconfigure(struct fs_context *fc) 234 { 235 struct super_block *sb = fc->root->d_sb; 236 237 sync_filesystem(sb); 238 jffs2_update_mount_opts(fc); 239 240 return jffs2_do_remount_fs(sb, fc); 241 } 242 243 static const struct super_operations jffs2_super_operations = 244 { 245 .alloc_inode = jffs2_alloc_inode, 246 .free_inode = jffs2_free_inode, 247 .put_super = jffs2_put_super, 248 .statfs = jffs2_statfs, 249 .evict_inode = jffs2_evict_inode, 250 .dirty_inode = jffs2_dirty_inode, 251 .show_options = jffs2_show_options, 252 .sync_fs = jffs2_sync_fs, 253 }; 254 255 /* 256 * fill in the superblock 257 */ 258 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc) 259 { 260 struct jffs2_sb_info *c = sb->s_fs_info; 261 262 jffs2_dbg(1, "jffs2_get_sb_mtd():" 263 " New superblock for device %d (\"%s\")\n", 264 sb->s_mtd->index, sb->s_mtd->name); 265 266 c->mtd = sb->s_mtd; 267 c->os_priv = sb; 268 269 if (c->mount_opts.rp_size > c->mtd->size) 270 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB", 271 c->mtd->size / 1024); 272 273 /* Initialize JFFS2 superblock locks, the further initialization will 274 * be done later */ 275 mutex_init(&c->alloc_sem); 276 mutex_init(&c->erase_free_sem); 277 init_waitqueue_head(&c->erase_wait); 278 init_waitqueue_head(&c->inocache_wq); 279 spin_lock_init(&c->erase_completion_lock); 280 spin_lock_init(&c->inocache_lock); 281 282 sb->s_op = &jffs2_super_operations; 283 sb->s_export_op = &jffs2_export_ops; 284 sb->s_flags = sb->s_flags | SB_NOATIME; 285 sb->s_xattr = jffs2_xattr_handlers; 286 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 287 sb->s_flags |= SB_POSIXACL; 288 #endif 289 return jffs2_do_fill_super(sb, fc); 290 } 291 292 static int jffs2_get_tree(struct fs_context *fc) 293 { 294 return get_tree_mtd(fc, jffs2_fill_super); 295 } 296 297 static void jffs2_free_fc(struct fs_context *fc) 298 { 299 kfree(fc->s_fs_info); 300 } 301 302 static const struct fs_context_operations jffs2_context_ops = { 303 .free = jffs2_free_fc, 304 .parse_param = jffs2_parse_param, 305 .get_tree = jffs2_get_tree, 306 .reconfigure = jffs2_reconfigure, 307 }; 308 309 static int jffs2_init_fs_context(struct fs_context *fc) 310 { 311 struct jffs2_sb_info *ctx; 312 313 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL); 314 if (!ctx) 315 return -ENOMEM; 316 317 fc->s_fs_info = ctx; 318 fc->ops = &jffs2_context_ops; 319 return 0; 320 } 321 322 static void jffs2_put_super (struct super_block *sb) 323 { 324 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 325 326 jffs2_dbg(2, "%s()\n", __func__); 327 328 mutex_lock(&c->alloc_sem); 329 jffs2_flush_wbuf_pad(c); 330 mutex_unlock(&c->alloc_sem); 331 332 jffs2_sum_exit(c); 333 334 jffs2_free_ino_caches(c); 335 jffs2_free_raw_node_refs(c); 336 kvfree(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 (c && !sb_rdonly(sb)) 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 .init_fs_context = jffs2_init_fs_context, 357 .parameters = jffs2_fs_parameters, 358 .kill_sb = jffs2_kill_sb, 359 }; 360 MODULE_ALIAS_FS("jffs2"); 361 362 static int __init init_jffs2_fs(void) 363 { 364 int ret; 365 366 /* Paranoia checks for on-medium structures. If we ask GCC 367 to pack them with __attribute__((packed)) then it _also_ 368 assumes that they're not aligned -- so it emits crappy 369 code on some architectures. Ideally we want an attribute 370 which means just 'no padding', without the alignment 371 thing. But GCC doesn't have that -- we have to just 372 hope the structs are the right sizes, instead. */ 373 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 374 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 375 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 376 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 377 378 pr_info("version 2.2." 379 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 380 " (NAND)" 381 #endif 382 #ifdef CONFIG_JFFS2_SUMMARY 383 " (SUMMARY) " 384 #endif 385 " © 2001-2006 Red Hat, Inc.\n"); 386 387 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 388 sizeof(struct jffs2_inode_info), 389 0, (SLAB_RECLAIM_ACCOUNT| 390 SLAB_ACCOUNT), 391 jffs2_i_init_once); 392 if (!jffs2_inode_cachep) { 393 pr_err("error: Failed to initialise inode cache\n"); 394 return -ENOMEM; 395 } 396 ret = jffs2_compressors_init(); 397 if (ret) { 398 pr_err("error: Failed to initialise compressors\n"); 399 goto out; 400 } 401 ret = jffs2_create_slab_caches(); 402 if (ret) { 403 pr_err("error: Failed to initialise slab caches\n"); 404 goto out_compressors; 405 } 406 ret = register_filesystem(&jffs2_fs_type); 407 if (ret) { 408 pr_err("error: Failed to register filesystem\n"); 409 goto out_slab; 410 } 411 return 0; 412 413 out_slab: 414 jffs2_destroy_slab_caches(); 415 out_compressors: 416 jffs2_compressors_exit(); 417 out: 418 kmem_cache_destroy(jffs2_inode_cachep); 419 return ret; 420 } 421 422 static void __exit exit_jffs2_fs(void) 423 { 424 unregister_filesystem(&jffs2_fs_type); 425 jffs2_destroy_slab_caches(); 426 jffs2_compressors_exit(); 427 428 /* 429 * Make sure all delayed rcu free inodes are flushed before we 430 * destroy cache. 431 */ 432 rcu_barrier(); 433 kmem_cache_destroy(jffs2_inode_cachep); 434 } 435 436 module_init(init_jffs2_fs); 437 module_exit(exit_jffs2_fs); 438 439 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 440 MODULE_AUTHOR("Red Hat, Inc."); 441 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 442 // the sake of this tag. It's Free Software. 443