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