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 = kmem_cache_alloc(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->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 .get_parent = jffs2_get_parent, 154 .fh_to_dentry = jffs2_fh_to_dentry, 155 .fh_to_parent = jffs2_fh_to_parent, 156 }; 157 158 /* 159 * JFFS2 mount options. 160 * 161 * Opt_source: The source device 162 * Opt_override_compr: override default compressor 163 * Opt_rp_size: size of reserved pool in KiB 164 */ 165 enum { 166 Opt_override_compr, 167 Opt_rp_size, 168 }; 169 170 static const struct fs_parameter_spec jffs2_param_specs[] = { 171 fsparam_enum ("compr", Opt_override_compr), 172 fsparam_u32 ("rp_size", Opt_rp_size), 173 {} 174 }; 175 176 static const struct fs_parameter_enum jffs2_param_enums[] = { 177 { Opt_override_compr, "none", JFFS2_COMPR_MODE_NONE }, 178 #ifdef CONFIG_JFFS2_LZO 179 { Opt_override_compr, "lzo", JFFS2_COMPR_MODE_FORCELZO }, 180 #endif 181 #ifdef CONFIG_JFFS2_ZLIB 182 { Opt_override_compr, "zlib", JFFS2_COMPR_MODE_FORCEZLIB }, 183 #endif 184 {} 185 }; 186 187 const struct fs_parameter_description jffs2_fs_parameters = { 188 .name = "jffs2", 189 .specs = jffs2_param_specs, 190 .enums = jffs2_param_enums, 191 }; 192 193 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param) 194 { 195 struct fs_parse_result result; 196 struct jffs2_sb_info *c = fc->s_fs_info; 197 int opt; 198 199 opt = fs_parse(fc, &jffs2_fs_parameters, param, &result); 200 if (opt < 0) 201 return opt; 202 203 switch (opt) { 204 case Opt_override_compr: 205 c->mount_opts.compr = result.uint_32; 206 c->mount_opts.override_compr = true; 207 break; 208 case Opt_rp_size: 209 if (result.uint_32 > UINT_MAX / 1024) 210 return invalf(fc, "jffs2: rp_size unrepresentable"); 211 opt = result.uint_32 * 1024; 212 if (opt > c->mtd->size) 213 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB", 214 c->mtd->size / 1024); 215 c->mount_opts.rp_size = opt; 216 break; 217 default: 218 return -EINVAL; 219 } 220 221 return 0; 222 } 223 224 static int jffs2_reconfigure(struct fs_context *fc) 225 { 226 struct super_block *sb = fc->root->d_sb; 227 228 sync_filesystem(sb); 229 return jffs2_do_remount_fs(sb, fc); 230 } 231 232 static const struct super_operations jffs2_super_operations = 233 { 234 .alloc_inode = jffs2_alloc_inode, 235 .free_inode = jffs2_free_inode, 236 .put_super = jffs2_put_super, 237 .statfs = jffs2_statfs, 238 .evict_inode = jffs2_evict_inode, 239 .dirty_inode = jffs2_dirty_inode, 240 .show_options = jffs2_show_options, 241 .sync_fs = jffs2_sync_fs, 242 }; 243 244 /* 245 * fill in the superblock 246 */ 247 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc) 248 { 249 struct jffs2_sb_info *c = sb->s_fs_info; 250 251 jffs2_dbg(1, "jffs2_get_sb_mtd():" 252 " New superblock for device %d (\"%s\")\n", 253 sb->s_mtd->index, sb->s_mtd->name); 254 255 c->mtd = sb->s_mtd; 256 c->os_priv = sb; 257 258 /* Initialize JFFS2 superblock locks, the further initialization will 259 * be done later */ 260 mutex_init(&c->alloc_sem); 261 mutex_init(&c->erase_free_sem); 262 init_waitqueue_head(&c->erase_wait); 263 init_waitqueue_head(&c->inocache_wq); 264 spin_lock_init(&c->erase_completion_lock); 265 spin_lock_init(&c->inocache_lock); 266 267 sb->s_op = &jffs2_super_operations; 268 sb->s_export_op = &jffs2_export_ops; 269 sb->s_flags = sb->s_flags | SB_NOATIME; 270 sb->s_xattr = jffs2_xattr_handlers; 271 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 272 sb->s_flags |= SB_POSIXACL; 273 #endif 274 return jffs2_do_fill_super(sb, fc); 275 } 276 277 static int jffs2_get_tree(struct fs_context *fc) 278 { 279 return get_tree_mtd(fc, jffs2_fill_super); 280 } 281 282 static void jffs2_free_fc(struct fs_context *fc) 283 { 284 kfree(fc->s_fs_info); 285 } 286 287 static const struct fs_context_operations jffs2_context_ops = { 288 .free = jffs2_free_fc, 289 .parse_param = jffs2_parse_param, 290 .get_tree = jffs2_get_tree, 291 .reconfigure = jffs2_reconfigure, 292 }; 293 294 static int jffs2_init_fs_context(struct fs_context *fc) 295 { 296 struct jffs2_sb_info *ctx; 297 298 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL); 299 if (!ctx) 300 return -ENOMEM; 301 302 fc->s_fs_info = ctx; 303 fc->ops = &jffs2_context_ops; 304 return 0; 305 } 306 307 static void jffs2_put_super (struct super_block *sb) 308 { 309 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 310 311 jffs2_dbg(2, "%s()\n", __func__); 312 313 mutex_lock(&c->alloc_sem); 314 jffs2_flush_wbuf_pad(c); 315 mutex_unlock(&c->alloc_sem); 316 317 jffs2_sum_exit(c); 318 319 jffs2_free_ino_caches(c); 320 jffs2_free_raw_node_refs(c); 321 kvfree(c->blocks); 322 jffs2_flash_cleanup(c); 323 kfree(c->inocache_list); 324 jffs2_clear_xattr_subsystem(c); 325 mtd_sync(c->mtd); 326 jffs2_dbg(1, "%s(): returning\n", __func__); 327 } 328 329 static void jffs2_kill_sb(struct super_block *sb) 330 { 331 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 332 if (c && !sb_rdonly(sb)) 333 jffs2_stop_garbage_collect_thread(c); 334 kill_mtd_super(sb); 335 kfree(c); 336 } 337 338 static struct file_system_type jffs2_fs_type = { 339 .owner = THIS_MODULE, 340 .name = "jffs2", 341 .init_fs_context = jffs2_init_fs_context, 342 .parameters = &jffs2_fs_parameters, 343 .kill_sb = jffs2_kill_sb, 344 }; 345 MODULE_ALIAS_FS("jffs2"); 346 347 static int __init init_jffs2_fs(void) 348 { 349 int ret; 350 351 /* Paranoia checks for on-medium structures. If we ask GCC 352 to pack them with __attribute__((packed)) then it _also_ 353 assumes that they're not aligned -- so it emits crappy 354 code on some architectures. Ideally we want an attribute 355 which means just 'no padding', without the alignment 356 thing. But GCC doesn't have that -- we have to just 357 hope the structs are the right sizes, instead. */ 358 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 359 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 360 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 361 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 362 363 pr_info("version 2.2." 364 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 365 " (NAND)" 366 #endif 367 #ifdef CONFIG_JFFS2_SUMMARY 368 " (SUMMARY) " 369 #endif 370 " © 2001-2006 Red Hat, Inc.\n"); 371 372 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 373 sizeof(struct jffs2_inode_info), 374 0, (SLAB_RECLAIM_ACCOUNT| 375 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 376 jffs2_i_init_once); 377 if (!jffs2_inode_cachep) { 378 pr_err("error: Failed to initialise inode cache\n"); 379 return -ENOMEM; 380 } 381 ret = jffs2_compressors_init(); 382 if (ret) { 383 pr_err("error: Failed to initialise compressors\n"); 384 goto out; 385 } 386 ret = jffs2_create_slab_caches(); 387 if (ret) { 388 pr_err("error: Failed to initialise slab caches\n"); 389 goto out_compressors; 390 } 391 ret = register_filesystem(&jffs2_fs_type); 392 if (ret) { 393 pr_err("error: Failed to register filesystem\n"); 394 goto out_slab; 395 } 396 return 0; 397 398 out_slab: 399 jffs2_destroy_slab_caches(); 400 out_compressors: 401 jffs2_compressors_exit(); 402 out: 403 kmem_cache_destroy(jffs2_inode_cachep); 404 return ret; 405 } 406 407 static void __exit exit_jffs2_fs(void) 408 { 409 unregister_filesystem(&jffs2_fs_type); 410 jffs2_destroy_slab_caches(); 411 jffs2_compressors_exit(); 412 413 /* 414 * Make sure all delayed rcu free inodes are flushed before we 415 * destroy cache. 416 */ 417 rcu_barrier(); 418 kmem_cache_destroy(jffs2_inode_cachep); 419 } 420 421 module_init(init_jffs2_fs); 422 module_exit(exit_jffs2_fs); 423 424 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 425 MODULE_AUTHOR("Red Hat, Inc."); 426 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 427 // the sake of this tag. It's Free Software. 428