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