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/super.h> 23 #include <linux/ctype.h> 24 #include <linux/namei.h> 25 #include <linux/exportfs.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 *f; 36 37 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 38 if (!f) 39 return NULL; 40 return &f->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) 49 { 50 struct jffs2_inode_info *f = foo; 51 52 mutex_init(&f->sem); 53 inode_init_once(&f->vfs_inode); 54 } 55 56 static void jffs2_write_super(struct super_block *sb) 57 { 58 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 59 60 lock_super(sb); 61 sb->s_dirt = 0; 62 63 if (!(sb->s_flags & MS_RDONLY)) { 64 D1(printk(KERN_DEBUG "jffs2_write_super()\n")); 65 jffs2_garbage_collect_trigger(c); 66 jffs2_erase_pending_blocks(c, 0); 67 jffs2_flush_wbuf_gc(c, 0); 68 } 69 70 unlock_super(sb); 71 } 72 73 static int jffs2_sync_fs(struct super_block *sb, int wait) 74 { 75 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 76 77 jffs2_write_super(sb); 78 79 mutex_lock(&c->alloc_sem); 80 jffs2_flush_wbuf_pad(c); 81 mutex_unlock(&c->alloc_sem); 82 return 0; 83 } 84 85 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 86 uint32_t generation) 87 { 88 /* We don't care about i_generation. We'll destroy the flash 89 before we start re-using inode numbers anyway. And even 90 if that wasn't true, we'd have other problems...*/ 91 return jffs2_iget(sb, ino); 92 } 93 94 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 95 int fh_len, int fh_type) 96 { 97 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 98 jffs2_nfs_get_inode); 99 } 100 101 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 102 int fh_len, int fh_type) 103 { 104 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 105 jffs2_nfs_get_inode); 106 } 107 108 static struct dentry *jffs2_get_parent(struct dentry *child) 109 { 110 struct jffs2_inode_info *f; 111 uint32_t pino; 112 113 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 114 115 f = JFFS2_INODE_INFO(child->d_inode); 116 117 pino = f->inocache->pino_nlink; 118 119 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 120 f->inocache->ino, pino); 121 122 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 123 } 124 125 static struct export_operations jffs2_export_ops = { 126 .get_parent = jffs2_get_parent, 127 .fh_to_dentry = jffs2_fh_to_dentry, 128 .fh_to_parent = jffs2_fh_to_parent, 129 }; 130 131 static const struct super_operations jffs2_super_operations = 132 { 133 .alloc_inode = jffs2_alloc_inode, 134 .destroy_inode =jffs2_destroy_inode, 135 .put_super = jffs2_put_super, 136 .write_super = jffs2_write_super, 137 .statfs = jffs2_statfs, 138 .remount_fs = jffs2_remount_fs, 139 .clear_inode = jffs2_clear_inode, 140 .dirty_inode = jffs2_dirty_inode, 141 .sync_fs = jffs2_sync_fs, 142 }; 143 144 /* 145 * fill in the superblock 146 */ 147 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 148 { 149 struct jffs2_sb_info *c; 150 151 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" 152 " New superblock for device %d (\"%s\")\n", 153 sb->s_mtd->index, sb->s_mtd->name)); 154 155 c = kzalloc(sizeof(*c), GFP_KERNEL); 156 if (!c) 157 return -ENOMEM; 158 159 c->mtd = sb->s_mtd; 160 c->os_priv = sb; 161 sb->s_fs_info = c; 162 163 /* Initialize JFFS2 superblock locks, the further initialization will 164 * be done later */ 165 mutex_init(&c->alloc_sem); 166 mutex_init(&c->erase_free_sem); 167 init_waitqueue_head(&c->erase_wait); 168 init_waitqueue_head(&c->inocache_wq); 169 spin_lock_init(&c->erase_completion_lock); 170 spin_lock_init(&c->inocache_lock); 171 172 sb->s_op = &jffs2_super_operations; 173 sb->s_export_op = &jffs2_export_ops; 174 sb->s_flags = sb->s_flags | MS_NOATIME; 175 sb->s_xattr = jffs2_xattr_handlers; 176 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 177 sb->s_flags |= MS_POSIXACL; 178 #endif 179 return jffs2_do_fill_super(sb, data, silent); 180 } 181 182 static int jffs2_get_sb(struct file_system_type *fs_type, 183 int flags, const char *dev_name, 184 void *data, struct vfsmount *mnt) 185 { 186 return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super, 187 mnt); 188 } 189 190 static void jffs2_put_super (struct super_block *sb) 191 { 192 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 193 194 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 195 196 lock_kernel(); 197 198 if (sb->s_dirt) 199 jffs2_write_super(sb); 200 201 mutex_lock(&c->alloc_sem); 202 jffs2_flush_wbuf_pad(c); 203 mutex_unlock(&c->alloc_sem); 204 205 jffs2_sum_exit(c); 206 207 jffs2_free_ino_caches(c); 208 jffs2_free_raw_node_refs(c); 209 if (jffs2_blocks_use_vmalloc(c)) 210 vfree(c->blocks); 211 else 212 kfree(c->blocks); 213 jffs2_flash_cleanup(c); 214 kfree(c->inocache_list); 215 jffs2_clear_xattr_subsystem(c); 216 if (c->mtd->sync) 217 c->mtd->sync(c->mtd); 218 219 unlock_kernel(); 220 221 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 222 } 223 224 static void jffs2_kill_sb(struct super_block *sb) 225 { 226 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 227 if (!(sb->s_flags & MS_RDONLY)) 228 jffs2_stop_garbage_collect_thread(c); 229 kill_mtd_super(sb); 230 kfree(c); 231 } 232 233 static struct file_system_type jffs2_fs_type = { 234 .owner = THIS_MODULE, 235 .name = "jffs2", 236 .get_sb = jffs2_get_sb, 237 .kill_sb = jffs2_kill_sb, 238 }; 239 240 static int __init init_jffs2_fs(void) 241 { 242 int ret; 243 244 /* Paranoia checks for on-medium structures. If we ask GCC 245 to pack them with __attribute__((packed)) then it _also_ 246 assumes that they're not aligned -- so it emits crappy 247 code on some architectures. Ideally we want an attribute 248 which means just 'no padding', without the alignment 249 thing. But GCC doesn't have that -- we have to just 250 hope the structs are the right sizes, instead. */ 251 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 252 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 253 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 254 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 255 256 printk(KERN_INFO "JFFS2 version 2.2." 257 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 258 " (NAND)" 259 #endif 260 #ifdef CONFIG_JFFS2_SUMMARY 261 " (SUMMARY) " 262 #endif 263 " © 2001-2006 Red Hat, Inc.\n"); 264 265 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 266 sizeof(struct jffs2_inode_info), 267 0, (SLAB_RECLAIM_ACCOUNT| 268 SLAB_MEM_SPREAD), 269 jffs2_i_init_once); 270 if (!jffs2_inode_cachep) { 271 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 272 return -ENOMEM; 273 } 274 ret = jffs2_compressors_init(); 275 if (ret) { 276 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 277 goto out; 278 } 279 ret = jffs2_create_slab_caches(); 280 if (ret) { 281 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 282 goto out_compressors; 283 } 284 ret = register_filesystem(&jffs2_fs_type); 285 if (ret) { 286 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 287 goto out_slab; 288 } 289 return 0; 290 291 out_slab: 292 jffs2_destroy_slab_caches(); 293 out_compressors: 294 jffs2_compressors_exit(); 295 out: 296 kmem_cache_destroy(jffs2_inode_cachep); 297 return ret; 298 } 299 300 static void __exit exit_jffs2_fs(void) 301 { 302 unregister_filesystem(&jffs2_fs_type); 303 jffs2_destroy_slab_caches(); 304 jffs2_compressors_exit(); 305 kmem_cache_destroy(jffs2_inode_cachep); 306 } 307 308 module_init(init_jffs2_fs); 309 module_exit(exit_jffs2_fs); 310 311 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 312 MODULE_AUTHOR("Red Hat, Inc."); 313 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 314 // the sake of this tag. It's Free Software. 315