fs/jffs2/super.c

   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 "compr.h"
  26 #include "nodelist.h"
  27
  28 static void jffs2_put_super(struct super_block *);
  29
  30 static struct kmem_cache *jffs2_inode_cachep;
  31
  32 static struct inode *jffs2_alloc_inode(struct super_block *sb)
  33 {
  34         struct jffs2_inode_info *ei;
  35         ei = (struct jffs2_inode_info *)kmem_cache_alloc(jffs2_inode_cachep, GFP_KERNEL);
  36         if (!ei)
  37                 return NULL;
  38         return &ei->vfs_inode;
  39 }
  40
  41 static void jffs2_destroy_inode(struct inode *inode)
  42 {
  43         kmem_cache_free(jffs2_inode_cachep, JFFS2_INODE_INFO(inode));
  44 }
  45
  46 static void jffs2_i_init_once(struct kmem_cache *cachep, void *foo)
  47 {
  48         struct jffs2_inode_info *ei = (struct jffs2_inode_info *) foo;
  49
  50         init_MUTEX(&ei->sem);
  51         inode_init_once(&ei->vfs_inode);
  52 }
  53
  54 static int jffs2_sync_fs(struct super_block *sb, int wait)
  55 {
  56         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
  57
  58         down(&c->alloc_sem);
  59         jffs2_flush_wbuf_pad(c);
  60         up(&c->alloc_sem);
  61         return 0;
  62 }
  63
  64 static const struct super_operations jffs2_super_operations =
  65 {
  66         .alloc_inode =  jffs2_alloc_inode,
  67         .destroy_inode =jffs2_destroy_inode,
  68         .read_inode =   jffs2_read_inode,
  69         .put_super =    jffs2_put_super,
  70         .write_super =  jffs2_write_super,
  71         .statfs =       jffs2_statfs,
  72         .remount_fs =   jffs2_remount_fs,
  73         .clear_inode =  jffs2_clear_inode,
  74         .dirty_inode =  jffs2_dirty_inode,
  75         .sync_fs =      jffs2_sync_fs,
  76 };
  77
  78 /*
  79  * fill in the superblock
  80  */
  81 static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
  82 {
  83         struct jffs2_sb_info *c;
  84
  85         D1(printk(KERN_DEBUG "jffs2_get_sb_mtd():"
  86                   " New superblock for device %d (\"%s\")\n",
  87                   sb->s_mtd->index, sb->s_mtd->name));
  88
  89         c = kzalloc(sizeof(*c), GFP_KERNEL);
  90         if (!c)
  91                 return -ENOMEM;
  92
  93         c->mtd = sb->s_mtd;
  94         c->os_priv = sb;
  95         sb->s_fs_info = c;
  96
  97         /* Initialize JFFS2 superblock locks, the further initialization will
  98          * be done later */
  99         init_MUTEX(&c->alloc_sem);
 100         init_MUTEX(&c->erase_free_sem);
 101         init_waitqueue_head(&c->erase_wait);
 102         init_waitqueue_head(&c->inocache_wq);
 103         spin_lock_init(&c->erase_completion_lock);
 104         spin_lock_init(&c->inocache_lock);
 105
 106         sb->s_op = &jffs2_super_operations;
 107         sb->s_flags = sb->s_flags | MS_NOATIME;
 108         sb->s_xattr = jffs2_xattr_handlers;
 109 #ifdef CONFIG_JFFS2_FS_POSIX_ACL
 110         sb->s_flags |= MS_POSIXACL;
 111 #endif
 112         return jffs2_do_fill_super(sb, data, silent);
 113 }
 114
 115 static int jffs2_get_sb(struct file_system_type *fs_type,
 116                         int flags, const char *dev_name,
 117                         void *data, struct vfsmount *mnt)
 118 {
 119         return get_sb_mtd(fs_type, flags, dev_name, data, jffs2_fill_super,
 120                           mnt);
 121 }
 122
 123 static void jffs2_put_super (struct super_block *sb)
 124 {
 125         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 126
 127         D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
 128
 129         down(&c->alloc_sem);
 130         jffs2_flush_wbuf_pad(c);
 131         up(&c->alloc_sem);
 132
 133         jffs2_sum_exit(c);
 134
 135         jffs2_free_ino_caches(c);
 136         jffs2_free_raw_node_refs(c);
 137         if (jffs2_blocks_use_vmalloc(c))
 138                 vfree(c->blocks);
 139         else
 140                 kfree(c->blocks);
 141         jffs2_flash_cleanup(c);
 142         kfree(c->inocache_list);
 143         jffs2_clear_xattr_subsystem(c);
 144         if (c->mtd->sync)
 145                 c->mtd->sync(c->mtd);
 146
 147         D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
 148 }
 149
 150 static void jffs2_kill_sb(struct super_block *sb)
 151 {
 152         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 153         if (!(sb->s_flags & MS_RDONLY))
 154                 jffs2_stop_garbage_collect_thread(c);
 155         kill_mtd_super(sb);
 156         kfree(c);
 157 }
 158
 159 static struct file_system_type jffs2_fs_type = {
 160         .owner =        THIS_MODULE,
 161         .name =         "jffs2",
 162         .get_sb =       jffs2_get_sb,
 163         .kill_sb =      jffs2_kill_sb,
 164 };
 165
 166 static int __init init_jffs2_fs(void)
 167 {
 168         int ret;
 169
 170         /* Paranoia checks for on-medium structures. If we ask GCC
 171            to pack them with __attribute__((packed)) then it _also_
 172            assumes that they're not aligned -- so it emits crappy
 173            code on some architectures. Ideally we want an attribute
 174            which means just 'no padding', without the alignment
 175            thing. But GCC doesn't have that -- we have to just
 176            hope the structs are the right sizes, instead. */
 177         BUILD_BUG_ON(sizeof(struct jffs2_unknown_node) != 12);
 178         BUILD_BUG_ON(sizeof(struct jffs2_raw_dirent) != 40);
 179         BUILD_BUG_ON(sizeof(struct jffs2_raw_inode) != 68);
 180         BUILD_BUG_ON(sizeof(struct jffs2_raw_summary) != 32);
 181
 182         printk(KERN_INFO "JFFS2 version 2.2."
 183 #ifdef CONFIG_JFFS2_FS_WRITEBUFFER
 184                " (NAND)"
 185 #endif
 186 #ifdef CONFIG_JFFS2_SUMMARY
 187                " (SUMMARY) "
 188 #endif
 189                " © 2001-2006 Red Hat, Inc.\n");
 190
 191         jffs2_inode_cachep = kmem_cache_create("jffs2_i",
 192                                              sizeof(struct jffs2_inode_info),
 193                                              0, (SLAB_RECLAIM_ACCOUNT|
 194                                                 SLAB_MEM_SPREAD),
 195                                              jffs2_i_init_once);
 196         if (!jffs2_inode_cachep) {
 197                 printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n");
 198                 return -ENOMEM;
 199         }
 200         ret = jffs2_compressors_init();
 201         if (ret) {
 202                 printk(KERN_ERR "JFFS2 error: Failed to initialise compressors\n");
 203                 goto out;
 204         }
 205         ret = jffs2_create_slab_caches();
 206         if (ret) {
 207                 printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
 208                 goto out_compressors;
 209         }
 210         ret = register_filesystem(&jffs2_fs_type);
 211         if (ret) {
 212                 printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
 213                 goto out_slab;
 214         }
 215         return 0;
 216
 217  out_slab:
 218         jffs2_destroy_slab_caches();
 219  out_compressors:
 220         jffs2_compressors_exit();
 221  out:
 222         kmem_cache_destroy(jffs2_inode_cachep);
 223         return ret;
 224 }
 225
 226 static void __exit exit_jffs2_fs(void)
 227 {
 228         unregister_filesystem(&jffs2_fs_type);
 229         jffs2_destroy_slab_caches();
 230         jffs2_compressors_exit();
 231         kmem_cache_destroy(jffs2_inode_cachep);
 232 }
 233
 234 module_init(init_jffs2_fs);
 235 module_exit(exit_jffs2_fs);
 236
 237 MODULE_DESCRIPTION("The Journalling Flash File System, v2");
 238 MODULE_AUTHOR("Red Hat, Inc.");
 239 MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
 240                        // the sake of this tag. It's Free Software.