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/config.h> 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/init.h> 19 #include <linux/list.h> 20 #include <linux/fs.h> 21 #include <linux/mount.h> 22 #include <linux/jffs2.h> 23 #include <linux/pagemap.h> 24 #include <linux/mtd/mtd.h> 25 #include <linux/ctype.h> 26 #include <linux/namei.h> 27 #include "compr.h" 28 #include "nodelist.h" 29 30 static void jffs2_put_super(struct super_block *); 31 32 static kmem_cache_t *jffs2_inode_cachep; 33 34 static struct inode *jffs2_alloc_inode(struct super_block *sb) 35 { 36 struct jffs2_inode_info *ei; 37 ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, SLAB_KERNEL); 38 if (!ei) 39 return NULL; 40 return &ei->vfs_inode; 41 } 42 43 static void jffs2_destroy_inode(struct inode *inode) 44 { 45 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 46 } 47 48 static void jffs2_i_init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) 49 { 50 struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo; 51 52 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == 53 SLAB_CTOR_CONSTRUCTOR) { 54 init_MUTEX(&ei->sem); 55 inode_init_once(&ei->vfs_inode); 56 } 57 } 58 59 static int jffs2_sync_fs(struct super_block *sb, int wait) 60 { 61 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 62 63 down(&c->alloc_sem); 64 jffs2_flush_wbuf_pad(c); 65 up(&c->alloc_sem); 66 return 0; 67 } 68 69 static struct super_operations jffs2_super_operations = 70 { 71 .alloc_inode = jffs2_alloc_inode, 72 .destroy_inode =jffs2_destroy_inode, 73 .read_inode = jffs2_read_inode, 74 .put_super = jffs2_put_super, 75 .write_super = jffs2_write_super, 76 .statfs = jffs2_statfs, 77 .remount_fs = jffs2_remount_fs, 78 .clear_inode = jffs2_clear_inode, 79 .dirty_inode = jffs2_dirty_inode, 80 .sync_fs = jffs2_sync_fs, 81 }; 82 83 static int jffs2_sb_compare(struct super_block *sb, void *data) 84 { 85 struct jffs2_sb_info *p = data; 86 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 87 88 /* The superblocks are considered to be equivalent if the underlying MTD 89 device is the same one */ 90 if (c->mtd == p->mtd) { 91 D1(printk(KERN_DEBUG "jffs2_sb_compare: match on device %d (\"%s\")\n", p->mtd->index, p->mtd->name)); 92 return 1; 93 } else { 94 D1(printk(KERN_DEBUG "jffs2_sb_compare: No match, device %d (\"%s\"), device %d (\"%s\")\n", 95 c->mtd->index, c->mtd->name, p->mtd->index, p->mtd->name)); 96 return 0; 97 } 98 } 99 100 static int jffs2_sb_set(struct super_block *sb, void *data) 101 { 102 struct jffs2_sb_info *p = data; 103 104 /* For persistence of NFS exports etc. we use the same s_dev 105 each time we mount the device, don't just use an anonymous 106 device */ 107 sb->s_fs_info = p; 108 p->os_priv = sb; 109 sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, p->mtd->index); 110 111 return 0; 112 } 113 114 static int jffs2_get_sb_mtd(struct file_system_type *fs_type, 115 int flags, const char *dev_name, 116 void *data, struct mtd_info *mtd, 117 struct vfsmount *mnt) 118 { 119 struct super_block *sb; 120 struct jffs2_sb_info *c; 121 int ret; 122 123 c = kmalloc(sizeof(*c), GFP_KERNEL); 124 if (!c) 125 return -ENOMEM; 126 memset(c, 0, sizeof(*c)); 127 c->mtd = mtd; 128 129 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); 130 131 if (IS_ERR(sb)) 132 goto out_error; 133 134 if (sb->s_root) { 135 /* New mountpoint for JFFS2 which is already mounted */ 136 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", 137 mtd->index, mtd->name)); 138 ret = simple_set_mnt(mnt, sb); 139 goto out_put; 140 } 141 142 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): New superblock for device %d (\"%s\")\n", 143 mtd->index, mtd->name)); 144 145 /* Initialize JFFS2 superblock locks, the further initialization will be 146 * done later */ 147 init_MUTEX(&c->alloc_sem); 148 init_MUTEX(&c->erase_free_sem); 149 init_waitqueue_head(&c->erase_wait); 150 init_waitqueue_head(&c->inocache_wq); 151 spin_lock_init(&c->erase_completion_lock); 152 spin_lock_init(&c->inocache_lock); 153 154 sb->s_op = &jffs2_super_operations; 155 sb->s_flags = flags | MS_NOATIME; 156 sb->s_xattr = jffs2_xattr_handlers; 157 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 158 sb->s_flags |= MS_POSIXACL; 159 #endif 160 ret = jffs2_do_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); 161 162 if (ret) { 163 /* Failure case... */ 164 up_write(&sb->s_umount); 165 deactivate_super(sb); 166 return ret; 167 } 168 169 sb->s_flags |= MS_ACTIVE; 170 return simple_set_mnt(mnt, sb); 171 172 out_error: 173 ret = PTR_ERR(sb); 174 out_put: 175 kfree(c); 176 put_mtd_device(mtd); 177 178 return ret; 179 } 180 181 static int jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 182 int flags, const char *dev_name, 183 void *data, int mtdnr, 184 struct vfsmount *mnt) 185 { 186 struct mtd_info *mtd; 187 188 mtd = get_mtd_device(NULL, mtdnr); 189 if (!mtd) { 190 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 191 return -EINVAL; 192 } 193 194 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 195 } 196 197 static int jffs2_get_sb(struct file_system_type *fs_type, 198 int flags, const char *dev_name, 199 void *data, struct vfsmount *mnt) 200 { 201 int err; 202 struct nameidata nd; 203 int mtdnr; 204 205 if (!dev_name) 206 return -EINVAL; 207 208 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 209 210 /* The preferred way of mounting in future; especially when 211 CONFIG_BLK_DEV is implemented - we specify the underlying 212 MTD device by number or by name, so that we don't require 213 block device support to be present in the kernel. */ 214 215 /* FIXME: How to do the root fs this way? */ 216 217 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 218 /* Probably mounting without the blkdev crap */ 219 if (dev_name[3] == ':') { 220 struct mtd_info *mtd; 221 222 /* Mount by MTD device name */ 223 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 224 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 225 mtd = get_mtd_device(NULL, mtdnr); 226 if (mtd) { 227 if (!strcmp(mtd->name, dev_name+4)) 228 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd, mnt); 229 put_mtd_device(mtd); 230 } 231 } 232 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 233 } else if (isdigit(dev_name[3])) { 234 /* Mount by MTD device number name */ 235 char *endptr; 236 237 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 238 if (!*endptr) { 239 /* It was a valid number */ 240 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 241 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 242 } 243 } 244 } 245 246 /* Try the old way - the hack where we allowed users to mount 247 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 248 249 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 250 251 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 252 err, nd.dentry->d_inode)); 253 254 if (err) 255 return err; 256 257 err = -EINVAL; 258 259 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 260 goto out; 261 262 if (nd.mnt->mnt_flags & MNT_NODEV) { 263 err = -EACCES; 264 goto out; 265 } 266 267 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 268 if (!(flags & MS_SILENT)) 269 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 270 dev_name); 271 goto out; 272 } 273 274 mtdnr = iminor(nd.dentry->d_inode); 275 path_release(&nd); 276 277 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr, mnt); 278 279 out: 280 path_release(&nd); 281 return err; 282 } 283 284 static void jffs2_put_super (struct super_block *sb) 285 { 286 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 287 288 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 289 290 down(&c->alloc_sem); 291 jffs2_flush_wbuf_pad(c); 292 up(&c->alloc_sem); 293 294 jffs2_sum_exit(c); 295 296 jffs2_free_ino_caches(c); 297 jffs2_free_raw_node_refs(c); 298 if (jffs2_blocks_use_vmalloc(c)) 299 vfree(c->blocks); 300 else 301 kfree(c->blocks); 302 jffs2_flash_cleanup(c); 303 kfree(c->inocache_list); 304 jffs2_clear_xattr_subsystem(c); 305 if (c->mtd->sync) 306 c->mtd->sync(c->mtd); 307 308 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 309 } 310 311 static void jffs2_kill_sb(struct super_block *sb) 312 { 313 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 314 if (!(sb->s_flags & MS_RDONLY)) 315 jffs2_stop_garbage_collect_thread(c); 316 generic_shutdown_super(sb); 317 put_mtd_device(c->mtd); 318 kfree(c); 319 } 320 321 static struct file_system_type jffs2_fs_type = { 322 .owner = THIS_MODULE, 323 .name = "jffs2", 324 .get_sb = jffs2_get_sb, 325 .kill_sb = jffs2_kill_sb, 326 }; 327 328 static int __init init_jffs2_fs(void) 329 { 330 int ret; 331 332 /* Paranoia checks for on-medium structures. If we ask GCC 333 to pack them with __attribute__((packed)) then it _also_ 334 assumes that they're not aligned -- so it emits crappy 335 code on some architectures. Ideally we want an attribute 336 which means just 'no padding', without the alignment 337 thing. But GCC doesn't have that -- we have to just 338 hope the structs are the right sizes, instead. */ 339 BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 340 BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 341 BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 342 BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 343 344 printk(KERN_INFO "JFFS2 version 2.2." 345 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 346 " (NAND)" 347 #endif 348 #ifdef CONFIG_JFFS2_SUMMARY 349 " (SUMMARY) " 350 #endif 351 " (C) 2001-2006 Red Hat, Inc.\n"); 352 353 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 354 sizeof(struct jffs2_inode_info), 355 0, (SLAB_RECLAIM_ACCOUNT| 356 SLAB_MEM_SPREAD), 357 jffs2_i_init_once, NULL); 358 if (!jffs2_inode_cachep) { 359 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 360 return -ENOMEM; 361 } 362 ret = jffs2_compressors_init(); 363 if (ret) { 364 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 365 goto out; 366 } 367 ret = jffs2_create_slab_caches(); 368 if (ret) { 369 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 370 goto out_compressors; 371 } 372 ret = register_filesystem(&jffs2_fs_type); 373 if (ret) { 374 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 375 goto out_slab; 376 } 377 return 0; 378 379 out_slab: 380 jffs2_destroy_slab_caches(); 381 out_compressors: 382 jffs2_compressors_exit(); 383 out: 384 kmem_cache_destroy(jffs2_inode_cachep); 385 return ret; 386 } 387 388 static void __exit exit_jffs2_fs(void) 389 { 390 unregister_filesystem(&jffs2_fs_type); 391 jffs2_destroy_slab_caches(); 392 jffs2_compressors_exit(); 393 kmem_cache_destroy(jffs2_inode_cachep); 394 } 395 396 module_init(init_jffs2_fs); 397 module_exit(exit_jffs2_fs); 398 399 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 400 MODULE_AUTHOR("Red Hat, Inc."); 401 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 402 // the sake of this tag. It's Free Software. 403