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_flush_wbuf_gc(c, 0); 66 } 67 68 unlock_super(sb); 69 } 70 71 static int jffs2_sync_fs(struct super_block *sb, int wait) 72 { 73 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 74 75 jffs2_write_super(sb); 76 77 mutex_lock(&c->alloc_sem); 78 jffs2_flush_wbuf_pad(c); 79 mutex_unlock(&c->alloc_sem); 80 return 0; 81 } 82 83 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 84 uint32_t generation) 85 { 86 /* We don't care about i_generation. We'll destroy the flash 87 before we start re-using inode numbers anyway. And even 88 if that wasn't true, we'd have other problems...*/ 89 return jffs2_iget(sb, ino); 90 } 91 92 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 93 int fh_len, int fh_type) 94 { 95 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 96 jffs2_nfs_get_inode); 97 } 98 99 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 100 int fh_len, int fh_type) 101 { 102 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 103 jffs2_nfs_get_inode); 104 } 105 106 static struct dentry *jffs2_get_parent(struct dentry *child) 107 { 108 struct jffs2_inode_info *f; 109 uint32_t pino; 110 111 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 112 113 f = JFFS2_INODE_INFO(child->d_inode); 114 115 pino = f->inocache->pino_nlink; 116 117 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 118 f->inocache->ino, pino); 119 120 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 121 } 122 123 static const struct export_operations jffs2_export_ops = { 124 .get_parent = jffs2_get_parent, 125 .fh_to_dentry = jffs2_fh_to_dentry, 126 .fh_to_parent = jffs2_fh_to_parent, 127 }; 128 129 static const struct super_operations jffs2_super_operations = 130 { 131 .alloc_inode = jffs2_alloc_inode, 132 .destroy_inode =jffs2_destroy_inode, 133 .put_super = jffs2_put_super, 134 .write_super = jffs2_write_super, 135 .statfs = jffs2_statfs, 136 .remount_fs = jffs2_remount_fs, 137 .evict_inode = jffs2_evict_inode, 138 .dirty_inode = jffs2_dirty_inode, 139 .sync_fs = jffs2_sync_fs, 140 }; 141 142 /* 143 * fill in the superblock 144 */ 145 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 146 { 147 struct jffs2_sb_info *c; 148 int ret; 149 150 D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():" 151 " New superblock for device %d (\"%s\")\n", 152 sb->s_mtd->index, sb->s_mtd->name)); 153 154 c = kzalloc(sizeof(*c), GFP_KERNEL); 155 if (!c) 156 return -ENOMEM; 157 158 c->mtd = sb->s_mtd; 159 c->os_priv = sb; 160 sb->s_fs_info = c; 161 162 /* Initialize JFFS2 superblock locks, the further initialization will 163 * be done later */ 164 mutex_init(&c->alloc_sem); 165 mutex_init(&c->erase_free_sem); 166 init_waitqueue_head(&c->erase_wait); 167 init_waitqueue_head(&c->inocache_wq); 168 spin_lock_init(&c->erase_completion_lock); 169 spin_lock_init(&c->inocache_lock); 170 171 sb->s_op = &jffs2_super_operations; 172 sb->s_export_op = &jffs2_export_ops; 173 sb->s_flags = sb->s_flags | MS_NOATIME; 174 sb->s_xattr = jffs2_xattr_handlers; 175 #ifdef CONFIG_JFFS2_FS_POSIX_ACL 176 sb->s_flags |= MS_POSIXACL; 177 #endif 178 ret = jffs2_do_fill_super(sb, data, silent); 179 return ret; 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 if (sb->s_dirt) 197 jffs2_write_super(sb); 198 199 mutex_lock(&c->alloc_sem); 200 jffs2_flush_wbuf_pad(c); 201 mutex_unlock(&c->alloc_sem); 202 203 jffs2_sum_exit(c); 204 205 jffs2_free_ino_caches(c); 206 jffs2_free_raw_node_refs(c); 207 if (jffs2_blocks_use_vmalloc(c)) 208 vfree(c->blocks); 209 else 210 kfree(c->blocks); 211 jffs2_flash_cleanup(c); 212 kfree(c->inocache_list); 213 jffs2_clear_xattr_subsystem(c); 214 if (c->mtd->sync) 215 c->mtd->sync(c->mtd); 216 217 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 218 } 219 220 static void jffs2_kill_sb(struct super_block *sb) 221 { 222 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 223 if (!(sb->s_flags & MS_RDONLY)) 224 jffs2_stop_garbage_collect_thread(c); 225 kill_mtd_super(sb); 226 kfree(c); 227 } 228 229 static struct file_system_type jffs2_fs_type = { 230 .owner = THIS_MODULE, 231 .name = "jffs2", 232 .get_sb = jffs2_get_sb, 233 .kill_sb = jffs2_kill_sb, 234 }; 235 236 static int __init init_jffs2_fs(void) 237 { 238 int ret; 239 240 /* Paranoia checks for on-medium structures. If we ask GCC 241 to pack them with __attribute__((packed)) then it _also_ 242 assumes that they're not aligned -- so it emits crappy 243 code on some architectures. Ideally we want an attribute 244 which means just 'no padding', without the alignment 245 thing. But GCC doesn't have that -- we have to just 246 hope the structs are the right sizes, instead. */ 247 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 248 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 249 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 250 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 251 252 printk(KERN_INFO "JFFS2 version 2.2." 253 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 254 " (NAND)" 255 #endif 256 #ifdef CONFIG_JFFS2_SUMMARY 257 " (SUMMARY) " 258 #endif 259 " © 2001-2006 Red Hat, Inc.\n"); 260 261 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 262 sizeof(struct jffs2_inode_info), 263 0, (SLAB_RECLAIM_ACCOUNT| 264 SLAB_MEM_SPREAD), 265 jffs2_i_init_once); 266 if (!jffs2_inode_cachep) { 267 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 268 return -ENOMEM; 269 } 270 ret = jffs2_compressors_init(); 271 if (ret) { 272 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 273 goto out; 274 } 275 ret = jffs2_create_slab_caches(); 276 if (ret) { 277 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 278 goto out_compressors; 279 } 280 ret = register_filesystem(&jffs2_fs_type); 281 if (ret) { 282 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 283 goto out_slab; 284 } 285 return 0; 286 287 out_slab: 288 jffs2_destroy_slab_caches(); 289 out_compressors: 290 jffs2_compressors_exit(); 291 out: 292 kmem_cache_destroy(jffs2_inode_cachep); 293 return ret; 294 } 295 296 static void __exit exit_jffs2_fs(void) 297 { 298 unregister_filesystem(&jffs2_fs_type); 299 jffs2_destroy_slab_caches(); 300 jffs2_compressors_exit(); 301 kmem_cache_destroy(jffs2_inode_cachep); 302 } 303 304 module_init(init_jffs2_fs); 305 module_exit(exit_jffs2_fs); 306 307 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 308 MODULE_AUTHOR("Red Hat, Inc."); 309 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 310 // the sake of this tag. It's Free Software. 311