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/smp_lock.h> 16 #include <linux/init.h> 17 #include <linux/list.h> 18 #include <linux/fs.h> 19 #include <linux/err.h> 20 #include <linux/mount.h> 21 #include <linux/jffs2.h> 22 #include <linux/pagemap.h> 23 #include <linux/mtd/super.h> 24 #include <linux/ctype.h> 25 #include <linux/namei.h> 26 #include <linux/exportfs.h> 27 #include "compr.h" 28 #include "nodelist.h" 29 30 static void jffs2_put_super(struct super_block *); 31 32 static struct kmem_cache *jffs2_inode_cachep; 33 34 static struct inode *jffs2_alloc_inode(struct super_block *sb) 35 { 36 struct jffs2_inode_info *f; 37 38 f = kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL); 39 if (!f) 40 return NULL; 41 return &f->vfs_inode; 42 } 43 44 static void jffs2_destroy_inode(struct inode *inode) 45 { 46 kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode)); 47 } 48 49 static void jffs2_i_init_once(void *foo) 50 { 51 struct jffs2_inode_info *f = foo; 52 53 mutex_init(&f->sem); 54 inode_init_once(&f->vfs_inode); 55 } 56 57 static void jffs2_write_super(struct super_block *sb) 58 { 59 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 60 61 lock_super(sb); 62 sb->s_dirt = 0; 63 64 if (!(sb->s_flags & MS_RDONLY)) { 65 D1(printk(KERN_DEBUG "jffs2_write_super()\n")); 66 jffs2_flush_wbuf_gc(c, 0); 67 } 68 69 unlock_super(sb); 70 } 71 72 static int jffs2_sync_fs(struct super_block *sb, int wait) 73 { 74 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 75 76 jffs2_write_super(sb); 77 78 mutex_lock(&c->alloc_sem); 79 jffs2_flush_wbuf_pad(c); 80 mutex_unlock(&c->alloc_sem); 81 return 0; 82 } 83 84 static struct inode *jffs2_nfs_get_inode(struct super_block *sb, uint64_t ino, 85 uint32_t generation) 86 { 87 /* We don't care about i_generation. We'll destroy the flash 88 before we start re-using inode numbers anyway. And even 89 if that wasn't true, we'd have other problems...*/ 90 return jffs2_iget(sb, ino); 91 } 92 93 static struct dentry *jffs2_fh_to_dentry(struct super_block *sb, struct fid *fid, 94 int fh_len, int fh_type) 95 { 96 return generic_fh_to_dentry(sb, fid, fh_len, fh_type, 97 jffs2_nfs_get_inode); 98 } 99 100 static struct dentry *jffs2_fh_to_parent(struct super_block *sb, struct fid *fid, 101 int fh_len, int fh_type) 102 { 103 return generic_fh_to_parent(sb, fid, fh_len, fh_type, 104 jffs2_nfs_get_inode); 105 } 106 107 static struct dentry *jffs2_get_parent(struct dentry *child) 108 { 109 struct jffs2_inode_info *f; 110 uint32_t pino; 111 112 BUG_ON(!S_ISDIR(child->d_inode->i_mode)); 113 114 f = JFFS2_INODE_INFO(child->d_inode); 115 116 pino = f->inocache->pino_nlink; 117 118 JFFS2_DEBUG("Parent of directory ino #%u is #%u\n", 119 f->inocache->ino, pino); 120 121 return d_obtain_alias(jffs2_iget(child->d_inode->i_sb, pino)); 122 } 123 124 static const struct export_operations jffs2_export_ops = { 125 .get_parent = jffs2_get_parent, 126 .fh_to_dentry = jffs2_fh_to_dentry, 127 .fh_to_parent = jffs2_fh_to_parent, 128 }; 129 130 static const struct super_operations jffs2_super_operations = 131 { 132 .alloc_inode = jffs2_alloc_inode, 133 .destroy_inode =jffs2_destroy_inode, 134 .put_super = jffs2_put_super, 135 .write_super = jffs2_write_super, 136 .statfs = jffs2_statfs, 137 .remount_fs = jffs2_remount_fs, 138 .evict_inode = jffs2_evict_inode, 139 .dirty_inode = jffs2_dirty_inode, 140 .sync_fs = jffs2_sync_fs, 141 }; 142 143 /* 144 * fill in the superblock 145 */ 146 static int jffs2_fill_super(struct super_block *sb, void *data, int silent) 147 { 148 struct jffs2_sb_info *c; 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 return jffs2_do_fill_super(sb, data, silent); 179 } 180 181 static int jffs2_get_sb(struct file_system_type *fs_type, 182 int flags, const char *dev_name, 183 void *data, struct vfsmount *mnt) 184 { 185 return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super, 186 mnt); 187 } 188 189 static void jffs2_put_super (struct super_block *sb) 190 { 191 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 192 193 D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n")); 194 195 lock_kernel(); 196 197 if (sb->s_dirt) 198 jffs2_write_super(sb); 199 200 mutex_lock(&c->alloc_sem); 201 jffs2_flush_wbuf_pad(c); 202 mutex_unlock(&c->alloc_sem); 203 204 jffs2_sum_exit(c); 205 206 jffs2_free_ino_caches(c); 207 jffs2_free_raw_node_refs(c); 208 if (jffs2_blocks_use_vmalloc(c)) 209 vfree(c->blocks); 210 else 211 kfree(c->blocks); 212 jffs2_flash_cleanup(c); 213 kfree(c->inocache_list); 214 jffs2_clear_xattr_subsystem(c); 215 if (c->mtd->sync) 216 c->mtd->sync(c->mtd); 217 218 unlock_kernel(); 219 220 D1(printk(KERN_DEBUG "jffs2_put_super returning\n")); 221 } 222 223 static void jffs2_kill_sb(struct super_block *sb) 224 { 225 struct jffs2_sb_info *c = JFFS2_SB_INFO(sb); 226 if (!(sb->s_flags & MS_RDONLY)) 227 jffs2_stop_garbage_collect_thread(c); 228 kill_mtd_super(sb); 229 kfree(c); 230 } 231 232 static struct file_system_type jffs2_fs_type = { 233 .owner = THIS_MODULE, 234 .name = "jffs2", 235 .get_sb = jffs2_get_sb, 236 .kill_sb = jffs2_kill_sb, 237 }; 238 239 static int __init init_jffs2_fs(void) 240 { 241 int ret; 242 243 /* Paranoia checks for on-medium structures. If we ask GCC 244 to pack them with __attribute__((packed)) then it _also_ 245 assumes that they're not aligned -- so it emits crappy 246 code on some architectures. Ideally we want an attribute 247 which means just 'no padding', without the alignment 248 thing. But GCC doesn't have that -- we have to just 249 hope the structs are the right sizes, instead. */ 250 BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12); 251 BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40); 252 BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68); 253 BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32); 254 255 printk(KERN_INFO "JFFS2 version 2.2." 256 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER 257 " (NAND)" 258 #endif 259 #ifdef CONFIG_JFFS2_SUMMARY 260 " (SUMMARY) " 261 #endif 262 " © 2001-2006 Red Hat, Inc.\n"); 263 264 jffs2_inode_cachep = kmem_cache_create("jffs2_i", 265 sizeof(struct jffs2_inode_info), 266 0, (SLAB_RECLAIM_ACCOUNT| 267 SLAB_MEM_SPREAD), 268 jffs2_i_init_once); 269 if (!jffs2_inode_cachep) { 270 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); 271 return -ENOMEM; 272 } 273 ret = jffs2_compressors_init(); 274 if (ret) { 275 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n"); 276 goto out; 277 } 278 ret = jffs2_create_slab_caches(); 279 if (ret) { 280 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n"); 281 goto out_compressors; 282 } 283 ret = register_filesystem(&jffs2_fs_type); 284 if (ret) { 285 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n"); 286 goto out_slab; 287 } 288 return 0; 289 290 out_slab: 291 jffs2_destroy_slab_caches(); 292 out_compressors: 293 jffs2_compressors_exit(); 294 out: 295 kmem_cache_destroy(jffs2_inode_cachep); 296 return ret; 297 } 298 299 static void __exit exit_jffs2_fs(void) 300 { 301 unregister_filesystem(&jffs2_fs_type); 302 jffs2_destroy_slab_caches(); 303 jffs2_compressors_exit(); 304 kmem_cache_destroy(jffs2_inode_cachep); 305 } 306 307 module_init(init_jffs2_fs); 308 module_exit(exit_jffs2_fs); 309 310 MODULE_DESCRIPTION("The Journalling Flash File System, v2"); 311 MODULE_AUTHOR("Red Hat, Inc."); 312 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for 313 // the sake of this tag. It's Free Software. 314