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 constant_table jffs2_param_compr[] = { 171 {"none", JFFS2_COMPR_MODE_NONE }, 172 #ifdef CONFIG_JFFS2_LZO 173 {"lzo", JFFS2_COMPR_MODE_FORCELZO }, 174 #endif 175 #ifdef CONFIG_JFFS2_ZLIB 176 {"zlib", JFFS2_COMPR_MODE_FORCEZLIB }, 177 #endif 178 {} 179 }; 180 181 static const struct fs_parameter_spec jffs2_fs_parameters[] = { 182 fsparam_enum ("compr", Opt_override_compr, jffs2_param_compr), 183 fsparam_u32 ("rp_size", Opt_rp_size), 184 {} 185 }; 186 187 static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param) 188 { 189 struct fs_parse_result result; 190 struct jffs2_sb_info *c = fc->s_fs_info; 191 int opt; 192 193 opt = fs_parse(fc, jffs2_fs_parameters, param, &result); 194 if (opt < 0) 195 return opt; 196 197 switch (opt) { 198 case Opt_override_compr: 199 c->mount_opts.compr = result.uint_32; 200 c->mount_opts.override_compr = true; 201 break; 202 case Opt_rp_size: 203 if (result.uint_32 > UINT_MAX / 1024) 204 return invalf(fc, "jffs2: rp_size unrepresentable"); 205 opt = result.uint_32 * 1024; 206 if (opt > c->mtd->size) 207 return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB", 208 c->mtd->size / 1024); 209 c->mount_opts.rp_size = opt; 210 break; 211 default: 212 return -EINVAL; 213 } 214 215 return 0; 216 } 217 218 static int jffs2_reconfigure(struct fs_context *fc) 219 { 220 struct super_block *sb = fc->root->d_sb; 221 222 sync_filesystem(sb); 223 return jffs2_do_remount_fs(sb, fc); 224 } 225 226 static const struct super_operations jffs2_super_operations = 227 { 228 .alloc_inode = jffs2_alloc_inode, 229 .free_inode = jffs2_free_inode, 230 .put_super = jffs2_put_super, 231 .statfs = jffs2_statfs, 232 .evict_inode = jffs2_evict_inode, 233 .dirty_inode = jffs2_dirty_inode, 234 .show_options = jffs2_show_options, 235 .sync_fs = jffs2_sync_fs, 236 }; 237 238 /* 239 * fill in the superblock 240 */ 241 static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc) 242 { 243 struct jffs2_sb_info *c = sb->s_fs_info; 244 245 jffs2_dbg(1, "jffs2_get_sb_mtd():" 246 " New superblock for device %d (\"%s\")\n", 247 sb->s_mtd->index, sb->s_mtd->name); 248 249 c->mtd = sb->s_mtd; 250 c->os_priv = sb; 251 252 /* Initialize JFFS2 superblock locks, the further initialization will 253 * be done later */ 254 mutex_init(&c->alloc_sem); 255 mutex_init(&c->erase_free_sem); 256 init_waitqueue_head(&c->erase_wait); 257 init_waitqueue_head(&c->inocache_wq); 258 spin_lock_init(&c->erase_completion_lock); 259 spin_lock_init(&c->inocache_lock); 260 261 sb->s_op = &jffs2_super_operations; 262 sb->s_export_op = &jffs2_export_ops; 263 sb->s_flags = sb->s_flags | SB_NOATIME; 264 sb->s_xattr = jffs2_xattr_handlers; 265 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 266 sb->s_flags |= SB_POSIXACL; 267 #endif 268 return jffs2_do_fill_super(sb, fc); 269 } 270 271 static int jffs2_get_tree(struct fs_context *fc) 272 { 273 return get_tree_mtd(fc, jffs2_fill_super); 274 } 275 276 static void jffs2_free_fc(struct fs_context *fc) 277 { 278 kfree(fc->s_fs_info); 279 } 280 281 static const struct fs_context_operations jffs2_context_ops = { 282 .free = jffs2_free_fc, 283 .parse_param = jffs2_parse_param, 284 .get_tree = jffs2_get_tree, 285 .reconfigure = jffs2_reconfigure, 286 }; 287 288 static int jffs2_init_fs_context(struct fs_context *fc) 289 { 290 struct jffs2_sb_info *ctx; 291 292 ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL); 293 if (!ctx) 294 return -ENOMEM; 295 296 fc->s_fs_info = ctx; 297 fc->ops = &jffs2_context_ops; 298 return 0; 299 } 300 301 static void jffs2_put_super (struct super_block *sb) 302 { 303 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 304 305 jffs2_dbg(2, "%s()\n", __func__); 306 307 mutex_lock(&c->alloc_sem); 308 jffs2_flush_wbuf_pad(c); 309 mutex_unlock(&c->alloc_sem); 310 311 jffs2_sum_exit(c); 312 313 jffs2_free_ino_caches(c); 314 jffs2_free_raw_node_refs(c); 315 kvfree(c->blocks); 316 jffs2_flash_cleanup(c); 317 kfree(c->inocache_list); 318 jffs2_clear_xattr_subsystem(c); 319 mtd_sync(c->mtd); 320 jffs2_dbg(1, "%s(): returning\n", __func__); 321 } 322 323 static void jffs2_kill_sb(struct super_block *sb) 324 { 325 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 326 if (c && !sb_rdonly(sb)) 327 jffs2_stop_garbage_collect_thread(c); 328 kill_mtd_super(sb); 329 kfree(c); 330 } 331 332 static struct file_system_type jffs2_fs_type = { 333 .owner = THIS_MODULE, 334 .name = "jffs2", 335 .init_fs_context = jffs2_init_fs_context, 336 .parameters = jffs2_fs_parameters, 337 .kill_sb = jffs2_kill_sb, 338 }; 339 MODULE_ALIAS_FS("jffs2"); 340 341 static int __init init_jffs2_fs(void) 342 { 343 int ret; 344 345 /* Paranoia checks for on-medium structures. If we ask GCC 346 to pack them with __attribute__((packed)) then it _also_ 347 assumes that they're not aligned -- so it emits crappy 348 code on some architectures. Ideally we want an attribute 349 which means just 'no padding', without the alignment 350 thing. But GCC doesn't have that -- we have to just 351 hope the structs are the right sizes, instead. */ 352 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 353 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 354 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 355 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 356 357 pr_info("version 2.2." 358 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 359 " (NAND)" 360 #endif 361 #ifdef CONFIG_JFFS2_SUMMARY 362 " (SUMMARY) " 363 #endif 364 " © 2001-2006 Red Hat, Inc.\n"); 365 366 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 367 sizeof(struct jffs2_inode_info), 368 0, (SLAB_RECLAIM_ACCOUNT| 369 SLAB_MEM_SPREAD|SLAB_ACCOUNT), 370 jffs2_i_init_once); 371 if (!jffs2_inode_cachep) { 372 pr_err("error: Failed to initialise inode cache\n"); 373 return -ENOMEM; 374 } 375 ret = jffs2_compressors_init(); 376 if (ret) { 377 pr_err("error: Failed to initialise compressors\n"); 378 goto out; 379 } 380 ret = jffs2_create_slab_caches(); 381 if (ret) { 382 pr_err("error: Failed to initialise slab caches\n"); 383 goto out_compressors; 384 } 385 ret = register_filesystem(&jffs2_fs_type); 386 if (ret) { 387 pr_err("error: Failed to register filesystem\n"); 388 goto out_slab; 389 } 390 return 0; 391 392 out_slab: 393 jffs2_destroy_slab_caches(); 394 out_compressors: 395 jffs2_compressors_exit(); 396 out: 397 kmem_cache_destroy(jffs2_inode_cachep); 398 return ret; 399 } 400 401 static void __exit exit_jffs2_fs(void) 402 { 403 unregister_filesystem(&jffs2_fs_type); 404 jffs2_destroy_slab_caches(); 405 jffs2_compressors_exit(); 406 407 /* 408 * Make sure all delayed rcu free inodes are flushed before we 409 * destroy cache. 410 */ 411 rcu_barrier(); 412 kmem_cache_destroy(jffs2_inode_cachep); 413 } 414 415 module_init(init_jffs2_fs); 416 module_exit(exit_jffs2_fs); 417 418 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 419 MODULE_AUTHOR("Red Hat, Inc."); 420 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 421 // the sake of this tag. It's Free Software. 422