1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 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 * $Id: super.c,v 1.110 2005/11/07 11:14:42 gleixner Exp $ 11 * 12 */ 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/mount.h> 21 #include <linux/jffs2.h> 22 #include <linux/pagemap.h> 23 #include <linux/mtd/mtd.h> 24 #include <linux/ctype.h> 25 #include <linux/namei.h> 26 #include "compr.h" 27 #include "nodelist.h" 28 29 static void jffs2_put_super(struct super_block *); 30 31 static struct kmem_cache *jffs2_inode_cachep; 32 33 static struct inode *jffs2_alloc_inode(struct super_block *sb) 34 { 35 struct jffs2_inode_info *ei; 36 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 37 if (!ei) 38 return NULL; 39 return &ei->vfs_inode; 40 } 41 42 static void jffs2_destroy_inode(struct inode *inode) 43 { 44 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 45 } 46 47 static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 48 { 49 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo; 50 51 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 52 SLAB_CTOR_CONSTRUCTOR) { 53 init_MUTEX(&ei->sem); 54 inode_init_once(&ei->vfs_inode); 55 } 56 } 57 58 static int jffs2_sync_fs(struct super_block *sb, int wait) 59 { 60 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 61 62 down(&c->alloc_sem); 63 jffs2_flush_wbuf_pad(c); 64 up(&c->alloc_sem); 65 return 0; 66 } 67 68 static struct super_operations jffs2_super_operations = 69 { 70 .alloc_inode = jffs2_alloc_inode, 71 .destroy_inode =jffs2_destroy_inode, 72 .read_inode = jffs2_read_inode, 73 .put_super = jffs2_put_super, 74 .write_super = jffs2_write_super, 75 .statfs = jffs2_statfs, 76 .remount_fs = jffs2_remount_fs, 77 .clear_inode = jffs2_clear_inode, 78 .dirty_inode = jffs2_dirty_inode, 79 .sync_fs = jffs2_sync_fs, 80 }; 81 82 static int jffs2_sb_compare(struct super_block *sb, void *data) 83 { 84 struct jffs2_sb_info *p = data; 85 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 86 87 /* The superblocks are considered to be equivalent if the underlying MTD 88 device is the same one */ 89 if (c->mtd == p->mtd) { 90 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name)); 91 return 1; 92 } else { 93 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n", 94 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name)); 95 return 0; 96 } 97 } 98 99 static int jffs2_sb_set(struct super_block *sb, void *data) 100 { 101 struct jffs2_sb_info *p = data; 102 103 /* For persistence of NFS exports etc. we use the same s_dev 104 each time we mount the device, don't just use an anonymous 105 device */ 106 sb->s_fs_info = p; 107 p->os_priv = sb; 108 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index); 109 110 return 0; 111 } 112 113 static int jffs2_get_sb_mtd(struct file_system_type *fs_type, 114 int flags, const char *dev_name, 115 void *data, struct mtd_info *mtd, 116 struct vfsmount *mnt) 117 { 118 struct super_block *sb; 119 struct jffs2_sb_info *c; 120 int ret; 121 122 c = kzalloc(sizeof(*c), GFP_KERNEL); 123 if (!c) 124 return -ENOMEM; 125 c->mtd = mtd; 126 127 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); 128 129 if (IS_ERR(sb)) 130 goto out_error; 131 132 if (sb->s_root) { 133 /* New mountpoint for JFFS2 which is already mounted */ 134 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", 135 mtd->index, mtd->name)); 136 ret = simple_set_mnt(mnt, sb); 137 goto out_put; 138 } 139 140 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n", 141 mtd->index, mtd->name)); 142 143 /* Initialize JFFS2 superblock locks, the further initialization will be 144 * done later */ 145 init_MUTEX(&c->alloc_sem); 146 init_MUTEX(&c->erase_free_sem); 147 init_waitqueue_head(&c->erase_wait); 148 init_waitqueue_head(&c->inocache_wq); 149 spin_lock_init(&c->erase_completion_lock); 150 spin_lock_init(&c->inocache_lock); 151 152 sb->s_op = &jffs2_super_operations; 153 sb->s_flags = flags | MS_NOATIME; 154 sb->s_xattr = jffs2_xattr_handlers; 155 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 156 sb->s_flags |= MS_POSIXACL; 157 #endif 158 ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); 159 160 if (ret) { 161 /* Failure case... */ 162 up_write(&sb->s_umount); 163 deactivate_super(sb); 164 return ret; 165 } 166 167 sb->s_flags |= MS_ACTIVE; 168 return simple_set_mnt(mnt, sb); 169 170 out_error: 171 ret = PTR_ERR(sb); 172 out_put: 173 kfree(c); 174 put_mtd_device(mtd); 175 176 return ret; 177 } 178 179 static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 180 int flags, const char *dev_name, 181 void *data, int mtdnr, 182 struct vfsmount *mnt) 183 { 184 struct mtd_info *mtd; 185 186 mtd = get_mtd_device(NULL, mtdnr); 187 if (!mtd) { 188 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 189 return -EINVAL; 190 } 191 192 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 193 } 194 195 static int jffs2_get_sb(struct file_system_type *fs_type, 196 int flags, const char *dev_name, 197 void *data, struct vfsmount *mnt) 198 { 199 int err; 200 struct nameidata nd; 201 int mtdnr; 202 203 if (!dev_name) 204 return -EINVAL; 205 206 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 207 208 /* The preferred way of mounting in future; especially when 209 CONFIG_BLK_DEV is implemented - we specify the underlying 210 MTD device by number or by name, so that we don't require 211 block device support to be present in the kernel. */ 212 213 /* FIXME: How to do the root fs this way? */ 214 215 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 216 /* Probably mounting without the blkdev crap */ 217 if (dev_name[3] == ':') { 218 struct mtd_info *mtd; 219 220 /* Mount by MTD device name */ 221 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 222 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 223 mtd = get_mtd_device(NULL, mtdnr); 224 if (mtd) { 225 if (!strcmp(mtd->name, dev_name+4)) 226 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 227 put_mtd_device(mtd); 228 } 229 } 230 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 231 } else if (isdigit(dev_name[3])) { 232 /* Mount by MTD device number name */ 233 char *endptr; 234 235 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 236 if (!*endptr) { 237 /* It was a valid number */ 238 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 239 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 240 } 241 } 242 } 243 244 /* Try the old way - the hack where we allowed users to mount 245 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 246 247 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 248 249 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 250 err, nd.dentry->d_inode)); 251 252 if (err) 253 return err; 254 255 err = -EINVAL; 256 257 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 258 goto out; 259 260 if (nd.mnt->mnt_flags & MNT_NODEV) { 261 err = -EACCES; 262 goto out; 263 } 264 265 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 266 if (!(flags & MS_SILENT)) 267 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 268 dev_name); 269 goto out; 270 } 271 272 mtdnr = iminor(nd.dentry->d_inode); 273 path_release(&nd); 274 275 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 276 277 out: 278 path_release(&nd); 279 return err; 280 } 281 282 static void jffs2_put_super (struct super_block *sb) 283 { 284 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 285 286 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 287 288 down(&c->alloc_sem); 289 jffs2_flush_wbuf_pad(c); 290 up(&c->alloc_sem); 291 292 jffs2_sum_exit(c); 293 294 jffs2_free_ino_caches(c); 295 jffs2_free_raw_node_refs(c); 296 if (jffs2_blocks_use_vmalloc(c)) 297 vfree(c->blocks); 298 else 299 kfree(c->blocks); 300 jffs2_flash_cleanup(c); 301 kfree(c->inocache_list); 302 jffs2_clear_xattr_subsystem(c); 303 if (c->mtd->sync) 304 c->mtd->sync(c->mtd); 305 306 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 307 } 308 309 static void jffs2_kill_sb(struct super_block *sb) 310 { 311 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 312 if (!(sb->s_flags & MS_RDONLY)) 313 jffs2_stop_garbage_collect_thread(c); 314 generic_shutdown_super(sb); 315 put_mtd_device(c->mtd); 316 kfree(c); 317 } 318 319 static struct file_system_type jffs2_fs_type = { 320 .owner = THIS_MODULE, 321 .name = "jffs2", 322 .get_sb = jffs2_get_sb, 323 .kill_sb = jffs2_kill_sb, 324 }; 325 326 static int __init init_jffs2_fs(void) 327 { 328 int ret; 329 330 /* Paranoia checks for on-medium structures. If we ask GCC 331 to pack them with __attribute__((packed)) then it _also_ 332 assumes that they're not aligned -- so it emits crappy 333 code on some architectures. Ideally we want an attribute 334 which means just 'no padding', without the alignment 335 thing. But GCC doesn't have that -- we have to just 336 hope the structs are the right sizes, instead. */ 337 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 338 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 339 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 340 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 341 342 printk(KERN_INFO "JFFS2 version 2.2." 343 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 344 " (NAND)" 345 #endif 346 #ifdef CONFIG_JFFS2_SUMMARY 347 " (SUMMARY) " 348 #endif 349 " (C) 2001-2006 Red Hat, Inc.\n"); 350 351 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 352 sizeof(struct jffs2_inode_info), 353 0, (SLAB_RECLAIM_ACCOUNT| 354 SLAB_MEM_SPREAD), 355 jffs2_i_init_once, NULL); 356 if (!jffs2_inode_cachep) { 357 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 358 return -ENOMEM; 359 } 360 ret = jffs2_compressors_init(); 361 if (ret) { 362 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 363 goto out; 364 } 365 ret = jffs2_create_slab_caches(); 366 if (ret) { 367 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 368 goto out_compressors; 369 } 370 ret = register_filesystem(&jffs2_fs_type); 371 if (ret) { 372 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 373 goto out_slab; 374 } 375 return 0; 376 377 out_slab: 378 jffs2_destroy_slab_caches(); 379 out_compressors: 380 jffs2_compressors_exit(); 381 out: 382 kmem_cache_destroy(jffs2_inode_cachep); 383 return ret; 384 } 385 386 static void __exit exit_jffs2_fs(void) 387 { 388 unregister_filesystem(&jffs2_fs_type); 389 jffs2_destroy_slab_caches(); 390 jffs2_compressors_exit(); 391 kmem_cache_destroy(jffs2_inode_cachep); 392 } 393 394 module_init(init_jffs2_fs); 395 module_exit(exit_jffs2_fs); 396 397 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 398 MODULE_AUTHOR("Red Hat, Inc."); 399 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 400 // the sake of this tag. It's Free Software. 401