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 1.107 2005/07/12 16:37:08 dedekind 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_LOCKED(&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 struct super_block *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 { 118 struct super_block *sb; 119 struct jffs2_sb_info *c; 120 int ret; 121 122 c = kmalloc(sizeof(*c), GFP_KERNEL); 123 if (!c) 124 return ERR_PTR(-ENOMEM); 125 memset(c, 0, sizeof(*c)); 126 c->mtd = mtd; 127 128 sb = sget(fs_type, jffs2_sb_compare, jffs2_sb_set, c); 129 130 if (IS_ERR(sb)) 131 goto out_put; 132 133 if (sb->s_root) { 134 /* New mountpoint for JFFS2 which is already mounted */ 135 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd(): Device %d (\"%s\") is already mounted\n", 136 mtd->index, mtd->name)); 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; 154 155 ret = jffs2_do_fill_super(sb, data, (flags&MS_VERBOSE)?1:0); 156 157 if (ret) { 158 /* Failure case... */ 159 up_write(&sb->s_umount); 160 deactivate_super(sb); 161 return ERR_PTR(ret); 162 } 163 164 sb->s_flags |= MS_ACTIVE; 165 return sb; 166 167 out_put: 168 kfree(c); 169 put_mtd_device(mtd); 170 171 return sb; 172 } 173 174 static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 175 int flags, const char *dev_name, 176 void *data, int mtdnr) 177 { 178 struct mtd_info *mtd; 179 180 mtd = get_mtd_device(NULL, mtdnr); 181 if (!mtd) { 182 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 183 return ERR_PTR(-EINVAL); 184 } 185 186 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); 187 } 188 189 static struct super_block *jffs2_get_sb(struct file_system_type *fs_type, 190 int flags, const char *dev_name, 191 void *data) 192 { 193 int err; 194 struct nameidata nd; 195 int mtdnr; 196 197 if (!dev_name) 198 return ERR_PTR(-EINVAL); 199 200 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 201 202 /* The preferred way of mounting in future; especially when 203 CONFIG_BLK_DEV is implemented - we specify the underlying 204 MTD device by number or by name, so that we don't require 205 block device support to be present in the kernel. */ 206 207 /* FIXME: How to do the root fs this way? */ 208 209 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 210 /* Probably mounting without the blkdev crap */ 211 if (dev_name[3] == ':') { 212 struct mtd_info *mtd; 213 214 /* Mount by MTD device name */ 215 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 216 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 217 mtd = get_mtd_device(NULL, mtdnr); 218 if (mtd) { 219 if (!strcmp(mtd->name, dev_name+4)) 220 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); 221 put_mtd_device(mtd); 222 } 223 } 224 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 225 } else if (isdigit(dev_name[3])) { 226 /* Mount by MTD device number name */ 227 char *endptr; 228 229 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 230 if (!*endptr) { 231 /* It was a valid number */ 232 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 233 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); 234 } 235 } 236 } 237 238 /* Try the old way - the hack where we allowed users to mount 239 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 240 241 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 242 243 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 244 err, nd.dentry->d_inode)); 245 246 if (err) 247 return ERR_PTR(err); 248 249 err = -EINVAL; 250 251 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 252 goto out; 253 254 if (nd.mnt->mnt_flags & MNT_NODEV) { 255 err = -EACCES; 256 goto out; 257 } 258 259 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 260 if (!(flags & MS_VERBOSE)) /* Yes I mean this. Strangely */ 261 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 262 dev_name); 263 goto out; 264 } 265 266 mtdnr = iminor(nd.dentry->d_inode); 267 path_release(&nd); 268 269 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); 270 271 out: 272 path_release(&nd); 273 return ERR_PTR(err); 274 } 275 276 static void jffs2_put_super (struct super_block *sb) 277 { 278 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 279 280 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 281 282 down(&c->alloc_sem); 283 jffs2_flush_wbuf_pad(c); 284 up(&c->alloc_sem); 285 jffs2_free_ino_caches(c); 286 jffs2_free_raw_node_refs(c); 287 if (c->mtd->flags & MTD_NO_VIRTBLOCKS) 288 vfree(c->blocks); 289 else 290 kfree(c->blocks); 291 jffs2_flash_cleanup(c); 292 kfree(c->inocache_list); 293 if (c->mtd->sync) 294 c->mtd->sync(c->mtd); 295 296 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 297 } 298 299 static void jffs2_kill_sb(struct super_block *sb) 300 { 301 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 302 if (!(sb->s_flags & MS_RDONLY)) 303 jffs2_stop_garbage_collect_thread(c); 304 generic_shutdown_super(sb); 305 put_mtd_device(c->mtd); 306 kfree(c); 307 } 308 309 static struct file_system_type jffs2_fs_type = { 310 .owner = THIS_MODULE, 311 .name = "jffs2", 312 .get_sb = jffs2_get_sb, 313 .kill_sb = jffs2_kill_sb, 314 }; 315 316 static int __init init_jffs2_fs(void) 317 { 318 int ret; 319 320 printk(KERN_INFO "JFFS2 version 2.2." 321 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 322 " (NAND)" 323 #endif 324 " (C) 2001-2003 Red Hat, Inc.\n"); 325 326 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 327 sizeof(struct jffs2_inode_info), 328 0, SLAB_RECLAIM_ACCOUNT, 329 jffs2_i_init_once, NULL); 330 if (!jffs2_inode_cachep) { 331 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 332 return -ENOMEM; 333 } 334 ret = jffs2_compressors_init(); 335 if (ret) { 336 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 337 goto out; 338 } 339 ret = jffs2_create_slab_caches(); 340 if (ret) { 341 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 342 goto out_compressors; 343 } 344 ret = register_filesystem(&jffs2_fs_type); 345 if (ret) { 346 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 347 goto out_slab; 348 } 349 return 0; 350 351 out_slab: 352 jffs2_destroy_slab_caches(); 353 out_compressors: 354 jffs2_compressors_exit(); 355 out: 356 kmem_cache_destroy(jffs2_inode_cachep); 357 return ret; 358 } 359 360 static void __exit exit_jffs2_fs(void) 361 { 362 unregister_filesystem(&jffs2_fs_type); 363 jffs2_destroy_slab_caches(); 364 jffs2_compressors_exit(); 365 kmem_cache_destroy(jffs2_inode_cachep); 366 } 367 368 module_init(init_jffs2_fs); 369 module_exit(exit_jffs2_fs); 370 371 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 372 MODULE_AUTHOR("Red Hat, Inc."); 373 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 374 // the sake of this tag. It's Free Software. 375