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 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/init.h> 16 #include <linux/list.h> 17 #include <linux/fs.h> 18 #include <linux/err.h> 19 #include <linux/mount.h> 20 #include <linux/jffs2.h> 21 #include <linux/pagemap.h> 22 #include <linux/mtd/mtd.h> 23 #include <linux/ctype.h> 24 #include <linux/namei.h> 25 #include "compr.h" 26 #include "nodelist.h" 27 28 static void jffs2_put_super(struct super_block *); 29 30 static struct kmem_cache *jffs2_inode_cachep; 31 32 static struct inode *jffs2_alloc_inode(struct super_block *sb) 33 { 34 struct jffs2_inode_info *ei; 35 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 36 if (!ei) 37 return NULL; 38 return &ei->vfs_inode; 39 } 40 41 static void jffs2_destroy_inode(struct inode *inode) 42 { 43 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 44 } 45 46 static void jffs2_i_init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) 47 { 48 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo; 49 50 if (flags & SLAB_CTOR_CONSTRUCTOR) { 51 init_MUTEX(&ei->sem); 52 inode_init_once(&ei->vfs_inode); 53 } 54 } 55 56 static int jffs2_sync_fs(struct super_block *sb, int wait) 57 { 58 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 59 60 down(&c->alloc_sem); 61 jffs2_flush_wbuf_pad(c); 62 up(&c->alloc_sem); 63 return 0; 64 } 65 66 static const struct super_operations jffs2_super_operations = 67 { 68 .alloc_inode = jffs2_alloc_inode, 69 .destroy_inode =jffs2_destroy_inode, 70 .read_inode = jffs2_read_inode, 71 .put_super = jffs2_put_super, 72 .write_super = jffs2_write_super, 73 .statfs = jffs2_statfs, 74 .remount_fs = jffs2_remount_fs, 75 .clear_inode = jffs2_clear_inode, 76 .dirty_inode = jffs2_dirty_inode, 77 .sync_fs = jffs2_sync_fs, 78 }; 79 80 static int jffs2_sb_compare(struct super_block *sb, void *data) 81 { 82 struct jffs2_sb_info *p = data; 83 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 84 85 /* The superblocks are considered to be equivalent if the underlying MTD 86 device is the same one */ 87 if (c->mtd == p->mtd) { 88 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name)); 89 return 1; 90 } else { 91 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n", 92 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name)); 93 return 0; 94 } 95 } 96 97 static int jffs2_sb_set(struct super_block *sb, void *data) 98 { 99 struct jffs2_sb_info *p = data; 100 101 /* For persistence of NFS exports etc. we use the same s_dev 102 each time we mount the device, don't just use an anonymous 103 device */ 104 sb->s_fs_info = p; 105 p->os_priv = sb; 106 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index); 107 108 return 0; 109 } 110 111 static int jffs2_get_sb_mtd(struct file_system_type *fs_type, 112 int flags, const char *dev_name, 113 void *data, struct mtd_info *mtd, 114 struct vfsmount *mnt) 115 { 116 struct super_block *sb; 117 struct jffs2_sb_info *c; 118 int ret; 119 120 c = kzalloc(sizeof(*c), GFP_KERNEL); 121 if (!c) 122 return -ENOMEM; 123 c->mtd = mtd; 124 125 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); 126 127 if (IS_ERR(sb)) 128 goto out_error; 129 130 if (sb->s_root) { 131 /* New mountpoint for JFFS2 which is already mounted */ 132 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", 133 mtd->index, mtd->name)); 134 ret = simple_set_mnt(mnt, sb); 135 goto out_put; 136 } 137 138 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n", 139 mtd->index, mtd->name)); 140 141 /* Initialize JFFS2 superblock locks, the further initialization will be 142 * done later */ 143 init_MUTEX(&c->alloc_sem); 144 init_MUTEX(&c->erase_free_sem); 145 init_waitqueue_head(&c->erase_wait); 146 init_waitqueue_head(&c->inocache_wq); 147 spin_lock_init(&c->erase_completion_lock); 148 spin_lock_init(&c->inocache_lock); 149 150 sb->s_op = &jffs2_super_operations; 151 sb->s_flags = flags | MS_NOATIME; 152 sb->s_xattr = jffs2_xattr_handlers; 153 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 154 sb->s_flags |= MS_POSIXACL; 155 #endif 156 ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); 157 158 if (ret) { 159 /* Failure case... */ 160 up_write(&sb->s_umount); 161 deactivate_super(sb); 162 return ret; 163 } 164 165 sb->s_flags |= MS_ACTIVE; 166 return simple_set_mnt(mnt, sb); 167 168 out_error: 169 ret = PTR_ERR(sb); 170 out_put: 171 kfree(c); 172 put_mtd_device(mtd); 173 174 return ret; 175 } 176 177 static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 178 int flags, const char *dev_name, 179 void *data, int mtdnr, 180 struct vfsmount *mnt) 181 { 182 struct mtd_info *mtd; 183 184 mtd = get_mtd_device(NULL, mtdnr); 185 if (IS_ERR(mtd)) { 186 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 187 return PTR_ERR(mtd); 188 } 189 190 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 191 } 192 193 static int jffs2_get_sb(struct file_system_type *fs_type, 194 int flags, const char *dev_name, 195 void *data, struct vfsmount *mnt) 196 { 197 int err; 198 struct nameidata nd; 199 int mtdnr; 200 201 if (!dev_name) 202 return -EINVAL; 203 204 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 205 206 /* The preferred way of mounting in future; especially when 207 CONFIG_BLK_DEV is implemented - we specify the underlying 208 MTD device by number or by name, so that we don't require 209 block device support to be present in the kernel. */ 210 211 /* FIXME: How to do the root fs this way? */ 212 213 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 214 /* Probably mounting without the blkdev crap */ 215 if (dev_name[3] == ':') { 216 struct mtd_info *mtd; 217 218 /* Mount by MTD device name */ 219 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 220 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 221 mtd = get_mtd_device(NULL, mtdnr); 222 if (!IS_ERR(mtd)) { 223 if (!strcmp(mtd->name, dev_name+4)) 224 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 225 put_mtd_device(mtd); 226 } 227 } 228 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 229 } else if (isdigit(dev_name[3])) { 230 /* Mount by MTD device number name */ 231 char *endptr; 232 233 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 234 if (!*endptr) { 235 /* It was a valid number */ 236 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 237 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 238 } 239 } 240 } 241 242 /* Try the old way - the hack where we allowed users to mount 243 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 244 245 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 246 247 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 248 err, nd.dentry->d_inode)); 249 250 if (err) 251 return err; 252 253 err = -EINVAL; 254 255 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 256 goto out; 257 258 if (nd.mnt->mnt_flags & MNT_NODEV) { 259 err = -EACCES; 260 goto out; 261 } 262 263 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 264 if (!(flags & MS_SILENT)) 265 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 266 dev_name); 267 goto out; 268 } 269 270 mtdnr = iminor(nd.dentry->d_inode); 271 path_release(&nd); 272 273 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 274 275 out: 276 path_release(&nd); 277 return err; 278 } 279 280 static void jffs2_put_super (struct super_block *sb) 281 { 282 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 283 284 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 285 286 down(&c->alloc_sem); 287 jffs2_flush_wbuf_pad(c); 288 up(&c->alloc_sem); 289 290 jffs2_sum_exit(c); 291 292 jffs2_free_ino_caches(c); 293 jffs2_free_raw_node_refs(c); 294 if (jffs2_blocks_use_vmalloc(c)) 295 vfree(c->blocks); 296 else 297 kfree(c->blocks); 298 jffs2_flash_cleanup(c); 299 kfree(c->inocache_list); 300 jffs2_clear_xattr_subsystem(c); 301 if (c->mtd->sync) 302 c->mtd->sync(c->mtd); 303 304 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 305 } 306 307 static void jffs2_kill_sb(struct super_block *sb) 308 { 309 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 310 if (!(sb->s_flags & MS_RDONLY)) 311 jffs2_stop_garbage_collect_thread(c); 312 generic_shutdown_super(sb); 313 put_mtd_device(c->mtd); 314 kfree(c); 315 } 316 317 static struct file_system_type jffs2_fs_type = { 318 .owner = THIS_MODULE, 319 .name = "jffs2", 320 .get_sb = jffs2_get_sb, 321 .kill_sb = jffs2_kill_sb, 322 }; 323 324 static int __init init_jffs2_fs(void) 325 { 326 int ret; 327 328 /* Paranoia checks for on-medium structures. If we ask GCC 329 to pack them with __attribute__((packed)) then it _also_ 330 assumes that they're not aligned -- so it emits crappy 331 code on some architectures. Ideally we want an attribute 332 which means just 'no padding', without the alignment 333 thing. But GCC doesn't have that -- we have to just 334 hope the structs are the right sizes, instead. */ 335 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 336 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 337 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 338 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 339 340 printk(KERN_INFO "JFFS2 version 2.2." 341 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 342 " (NAND)" 343 #endif 344 #ifdef CONFIG_JFFS2_SUMMARY 345 " (SUMMARY) " 346 #endif 347 " © 2001-2006 Red Hat, Inc.\n"); 348 349 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 350 sizeof(struct jffs2_inode_info), 351 0, (SLAB_RECLAIM_ACCOUNT| 352 SLAB_MEM_SPREAD), 353 jffs2_i_init_once, NULL); 354 if (!jffs2_inode_cachep) { 355 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 356 return -ENOMEM; 357 } 358 ret = jffs2_compressors_init(); 359 if (ret) { 360 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 361 goto out; 362 } 363 ret = jffs2_create_slab_caches(); 364 if (ret) { 365 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 366 goto out_compressors; 367 } 368 ret = register_filesystem(&jffs2_fs_type); 369 if (ret) { 370 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 371 goto out_slab; 372 } 373 return 0; 374 375 out_slab: 376 jffs2_destroy_slab_caches(); 377 out_compressors: 378 jffs2_compressors_exit(); 379 out: 380 kmem_cache_destroy(jffs2_inode_cachep); 381 return ret; 382 } 383 384 static void __exit exit_jffs2_fs(void) 385 { 386 unregister_filesystem(&jffs2_fs_type); 387 jffs2_destroy_slab_caches(); 388 jffs2_compressors_exit(); 389 kmem_cache_destroy(jffs2_inode_cachep); 390 } 391 392 module_init(init_jffs2_fs); 393 module_exit(exit_jffs2_fs); 394 395 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 396 MODULE_AUTHOR("Red Hat, Inc."); 397 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 398 // the sake of this tag. It's Free Software. 399