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 1.104 2004/11/23 15:37:31 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_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 sb->s_op = &jffs2_super_operations; 144 sb->s_flags = flags | MS_NOATIME; 145 146 ret = jffs2_do_fill_super(sb, data, (flags&MS_VERBOSE)?1:0); 147 148 if (ret) { 149 /* Failure case... */ 150 up_write(&sb->s_umount); 151 deactivate_super(sb); 152 return ERR_PTR(ret); 153 } 154 155 sb->s_flags |= MS_ACTIVE; 156 return sb; 157 158 out_put: 159 kfree(c); 160 put_mtd_device(mtd); 161 162 return sb; 163 } 164 165 static struct super_block *jffs2_get_sb_mtdnr(struct file_system_type *fs_type, 166 int flags, const char *dev_name, 167 void *data, int mtdnr) 168 { 169 struct mtd_info *mtd; 170 171 mtd = get_mtd_device(NULL, mtdnr); 172 if (!mtd) { 173 D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", mtdnr)); 174 return ERR_PTR(-EINVAL); 175 } 176 177 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); 178 } 179 180 static struct super_block *jffs2_get_sb(struct file_system_type *fs_type, 181 int flags, const char *dev_name, 182 void *data) 183 { 184 int err; 185 struct nameidata nd; 186 int mtdnr; 187 188 if (!dev_name) 189 return ERR_PTR(-EINVAL); 190 191 D1(printk(KERN_DEBUG "jffs2_get_sb(): dev_name \"%s\"\n", dev_name)); 192 193 /* The preferred way of mounting in future; especially when 194 CONFIG_BLK_DEV is implemented - we specify the underlying 195 MTD device by number or by name, so that we don't require 196 block device support to be present in the kernel. */ 197 198 /* FIXME: How to do the root fs this way? */ 199 200 if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') { 201 /* Probably mounting without the blkdev crap */ 202 if (dev_name[3] == ':') { 203 struct mtd_info *mtd; 204 205 /* Mount by MTD device name */ 206 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd:%%s, name \"%s\"\n", dev_name+4)); 207 for (mtdnr = 0; mtdnr < MAX_MTD_DEVICES; mtdnr++) { 208 mtd = get_mtd_device(NULL, mtdnr); 209 if (mtd) { 210 if (!strcmp(mtd->name, dev_name+4)) 211 return jffs2_get_sb_mtd(fs_type, flags, dev_name, data, mtd); 212 put_mtd_device(mtd); 213 } 214 } 215 printk(KERN_NOTICE "jffs2_get_sb(): MTD device with name \"%s\" not found.\n", dev_name+4); 216 } else if (isdigit(dev_name[3])) { 217 /* Mount by MTD device number name */ 218 char *endptr; 219 220 mtdnr = simple_strtoul(dev_name+3, &endptr, 0); 221 if (!*endptr) { 222 /* It was a valid number */ 223 D1(printk(KERN_DEBUG "jffs2_get_sb(): mtd%%d, mtdnr %d\n", mtdnr)); 224 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); 225 } 226 } 227 } 228 229 /* Try the old way - the hack where we allowed users to mount 230 /dev/mtdblock$(n) but didn't actually _use_ the blkdev */ 231 232 err = path_lookup(dev_name, LOOKUP_FOLLOW, &nd); 233 234 D1(printk(KERN_DEBUG "jffs2_get_sb(): path_lookup() returned %d, inode %p\n", 235 err, nd.dentry->d_inode)); 236 237 if (err) 238 return ERR_PTR(err); 239 240 err = -EINVAL; 241 242 if (!S_ISBLK(nd.dentry->d_inode->i_mode)) 243 goto out; 244 245 if (nd.mnt->mnt_flags & MNT_NODEV) { 246 err = -EACCES; 247 goto out; 248 } 249 250 if (imajor(nd.dentry->d_inode) != MTD_BLOCK_MAJOR) { 251 if (!(flags & MS_VERBOSE)) /* Yes I mean this. Strangely */ 252 printk(KERN_NOTICE "Attempt to mount non-MTD device \"%s\" as JFFS2\n", 253 dev_name); 254 goto out; 255 } 256 257 mtdnr = iminor(nd.dentry->d_inode); 258 path_release(&nd); 259 260 return jffs2_get_sb_mtdnr(fs_type, flags, dev_name, data, mtdnr); 261 262 out: 263 path_release(&nd); 264 return ERR_PTR(err); 265 } 266 267 static void jffs2_put_super (struct super_block *sb) 268 { 269 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 270 271 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 272 273 if (!(sb->s_flags & MS_RDONLY)) 274 jffs2_stop_garbage_collect_thread(c); 275 down(&c->alloc_sem); 276 jffs2_flush_wbuf_pad(c); 277 up(&c->alloc_sem); 278 jffs2_free_ino_caches(c); 279 jffs2_free_raw_node_refs(c); 280 if (c->mtd->flags & MTD_NO_VIRTBLOCKS) 281 vfree(c->blocks); 282 else 283 kfree(c->blocks); 284 jffs2_flash_cleanup(c); 285 kfree(c->inocache_list); 286 if (c->mtd->sync) 287 c->mtd->sync(c->mtd); 288 289 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 290 } 291 292 static void jffs2_kill_sb(struct super_block *sb) 293 { 294 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 295 generic_shutdown_super(sb); 296 put_mtd_device(c->mtd); 297 kfree(c); 298 } 299 300 static struct file_system_type jffs2_fs_type = { 301 .owner = THIS_MODULE, 302 .name = "jffs2", 303 .get_sb = jffs2_get_sb, 304 .kill_sb = jffs2_kill_sb, 305 }; 306 307 static int __init init_jffs2_fs(void) 308 { 309 int ret; 310 311 printk(KERN_INFO "JFFS2 version 2.2." 312 #ifdef CONFIG_JFFS2_FS_NAND 313 " (NAND)" 314 #endif 315 " (C) 2001-2003 Red Hat, Inc.\n"); 316 317 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 318 sizeof(struct jffs2_inode_info), 319 0, SLAB_RECLAIM_ACCOUNT, 320 jffs2_i_init_once, NULL); 321 if (!jffs2_inode_cachep) { 322 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 323 return -ENOMEM; 324 } 325 ret = jffs2_compressors_init(); 326 if (ret) { 327 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 328 goto out; 329 } 330 ret = jffs2_create_slab_caches(); 331 if (ret) { 332 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 333 goto out_compressors; 334 } 335 ret = register_filesystem(&jffs2_fs_type); 336 if (ret) { 337 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 338 goto out_slab; 339 } 340 return 0; 341 342 out_slab: 343 jffs2_destroy_slab_caches(); 344 out_compressors: 345 jffs2_compressors_exit(); 346 out: 347 kmem_cache_destroy(jffs2_inode_cachep); 348 return ret; 349 } 350 351 static void __exit exit_jffs2_fs(void) 352 { 353 unregister_filesystem(&jffs2_fs_type); 354 jffs2_destroy_slab_caches(); 355 jffs2_compressors_exit(); 356 kmem_cache_destroy(jffs2_inode_cachep); 357 } 358 359 module_init(init_jffs2_fs); 360 module_exit(exit_jffs2_fs); 361 362 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 363 MODULE_AUTHOR("Red Hat, Inc."); 364 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 365 // the sake of this tag. It's Free Software. 366