/*
   *  linux/fs/hfs/super.c
   *
   * Copyright (C) 1995-1997  Paul H. Hargrove
   * (C) 2003 Ardis Technologies <roman@ardistech.com>
   * This file may be distributed under the terms of the GNU General Public License.
   *
   * This file contains hfs_read_super(), some of the super_ops and

   * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in

   * inode.c since they deal with inodes.
   *
   * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
   */

  #include <linux/module.h>
  #include <linux/blkdev.h>

  #include <linux/mount.h>

  #include <linux/init.h>

  #include <linux/nls.h>

  #include <linux/parser.h>

  #include <linux/seq_file.h>

  #include <linux/slab.h>

  #include <linux/vfs.h>
  
  #include "hfs_fs.h"
  #include "btree.h"

  static struct kmem_cache *hfs_inode_cachep;

  
  MODULE_LICENSE("GPL");
  
  /*
   * hfs_write_super()
   *
   * Description:
   *   This function is called by the VFS only. When the filesystem
   *   is mounted r/w it updates the MDB on disk.
   * Input Variable(s):
   *   struct super_block *sb: Pointer to the hfs superblock
   * Output Variable(s):
   *   NONE
   * Returns:
   *   void
   * Preconditions:
   *   'sb' points to a "valid" (struct super_block).
   * Postconditions:
   *   The MDB is marked 'unsuccessfully unmounted' by clearing bit 8 of drAtrb
   *   (hfs_put_super() must set this flag!). Some MDB fields are updated
   *   and the MDB buffer is written to disk by calling hfs_mdb_commit().
   */
  static void hfs_write_super(struct super_block *sb)
  {

  	lock_super(sb);

  	sb->s_dirt = 0;

  	/* sync everything to the buffers */

  	if (!(sb->s_flags & MS_RDONLY))
  		hfs_mdb_commit(sb);
  	unlock_super(sb);

  }

  static int hfs_sync_fs(struct super_block *sb, int wait)
  {
  	lock_super(sb);
  	hfs_mdb_commit(sb);
  	sb->s_dirt = 0;
  	unlock_super(sb);
  
  	return 0;
  }

  /*
   * hfs_put_super()
   *
   * This is the put_super() entry in the super_operations structure for
   * HFS filesystems.  The purpose is to release the resources
   * associated with the superblock sb.
   */
  static void hfs_put_super(struct super_block *sb)
  {

  	if (sb->s_dirt)
  		hfs_write_super(sb);

  	hfs_mdb_close(sb);
  	/* release the MDB's resources */
  	hfs_mdb_put(sb);
  }
  
  /*
   * hfs_statfs()
   *
   * This is the statfs() entry in the super_operations structure for
   * HFS filesystems.  The purpose is to return various data about the
   * filesystem.
   *
   * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
   */

  static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)

  {

  	struct super_block *sb = dentry->d_sb;

  	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);

  	buf->f_type = HFS_SUPER_MAGIC;
  	buf->f_bsize = sb->s_blocksize;
  	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
  	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
  	buf->f_bavail = buf->f_bfree;
  	buf->f_files = HFS_SB(sb)->fs_ablocks;
  	buf->f_ffree = HFS_SB(sb)->free_ablocks;

  	buf->f_fsid.val[0] = (u32)id;
  	buf->f_fsid.val[1] = (u32)(id >> 32);

  	buf->f_namelen = HFS_NAMELEN;
  
  	return 0;
  }
  
  static int hfs_remount(struct super_block *sb, int *flags, char *data)
  {
  	*flags |= MS_NODIRATIME;
  	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
  		return 0;
  	if (!(*flags & MS_RDONLY)) {
  		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {

  			printk(KERN_WARNING "hfs: filesystem was not cleanly unmounted, "

  			       "running fsck.hfs is recommended.  leaving read-only.
  ");
  			sb->s_flags |= MS_RDONLY;
  			*flags |= MS_RDONLY;
  		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {

  			printk(KERN_WARNING "hfs: filesystem is marked locked, leaving read-only.
  ");

  			sb->s_flags |= MS_RDONLY;
  			*flags |= MS_RDONLY;
  		}
  	}
  	return 0;
  }

  static int hfs_show_options(struct seq_file *seq, struct dentry *root)

  {

  	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);

  
  	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
  		seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
  	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
  		seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
  	seq_printf(seq, ",uid=%u,gid=%u", sbi->s_uid, sbi->s_gid);
  	if (sbi->s_file_umask != 0133)
  		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
  	if (sbi->s_dir_umask != 0022)
  		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
  	if (sbi->part >= 0)
  		seq_printf(seq, ",part=%u", sbi->part);
  	if (sbi->session >= 0)
  		seq_printf(seq, ",session=%u", sbi->session);

  	if (sbi->nls_disk)
  		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
  	if (sbi->nls_io)
  		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);

  	if (sbi->s_quiet)
  		seq_printf(seq, ",quiet");
  	return 0;
  }

  static struct inode *hfs_alloc_inode(struct super_block *sb)
  {
  	struct hfs_inode_info *i;

  	i = kmem_cache_alloc(hfs_inode_cachep, GFP_KERNEL);

  	return i ? &i->vfs_inode : NULL;
  }

  static void hfs_i_callback(struct rcu_head *head)

  {

  	struct inode *inode = container_of(head, struct inode, i_rcu);

  	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
  }

  static void hfs_destroy_inode(struct inode *inode)
  {
  	call_rcu(&inode->i_rcu, hfs_i_callback);
  }

  static const struct super_operations hfs_super_operations = {

  	.alloc_inode	= hfs_alloc_inode,
  	.destroy_inode	= hfs_destroy_inode,
  	.write_inode	= hfs_write_inode,

  	.evict_inode	= hfs_evict_inode,

  	.put_super	= hfs_put_super,
  	.write_super	= hfs_write_super,

  	.sync_fs	= hfs_sync_fs,

  	.statfs		= hfs_statfs,
  	.remount_fs     = hfs_remount,

  	.show_options	= hfs_show_options,

  };
  
  enum {
  	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
  	opt_part, opt_session, opt_type, opt_creator, opt_quiet,

  	opt_codepage, opt_iocharset,

  	opt_err
  };

  static const match_table_t tokens = {

  	{ opt_uid, "uid=%u" },
  	{ opt_gid, "gid=%u" },
  	{ opt_umask, "umask=%o" },
  	{ opt_file_umask, "file_umask=%o" },
  	{ opt_dir_umask, "dir_umask=%o" },
  	{ opt_part, "part=%u" },
  	{ opt_session, "session=%u" },
  	{ opt_type, "type=%s" },
  	{ opt_creator, "creator=%s" },
  	{ opt_quiet, "quiet" },

  	{ opt_codepage, "codepage=%s" },
  	{ opt_iocharset, "iocharset=%s" },

  	{ opt_err, NULL }
  };
  
  static inline int match_fourchar(substring_t *arg, u32 *result)
  {
  	if (arg->to - arg->from != 4)
  		return -EINVAL;
  	memcpy(result, arg->from, 4);
  	return 0;
  }
  
  /*
   * parse_options()
   *
   * adapted from linux/fs/msdos/inode.c written 1992,93 by Werner Almesberger
   * This function is called by hfs_read_super() to parse the mount options.
   */
  static int parse_options(char *options, struct hfs_sb_info *hsb)
  {
  	char *p;
  	substring_t args[MAX_OPT_ARGS];
  	int tmp, token;
  
  	/* initialize the sb with defaults */

  	hsb->s_uid = current_uid();
  	hsb->s_gid = current_gid();

  	hsb->s_file_umask = 0133;
  	hsb->s_dir_umask = 0022;
  	hsb->s_type = hsb->s_creator = cpu_to_be32(0x3f3f3f3f);	/* == '????' */
  	hsb->s_quiet = 0;
  	hsb->part = -1;
  	hsb->session = -1;
  
  	if (!options)
  		return 1;
  
  	while ((p = strsep(&options, ",")) != NULL) {
  		if (!*p)
  			continue;
  
  		token = match_token(p, tokens, args);
  		switch (token) {
  		case opt_uid:
  			if (match_int(&args[0], &tmp)) {

  				printk(KERN_ERR "hfs: uid requires an argument
  ");

  				return 0;
  			}
  			hsb->s_uid = (uid_t)tmp;
  			break;
  		case opt_gid:
  			if (match_int(&args[0], &tmp)) {

  				printk(KERN_ERR "hfs: gid requires an argument
  ");

  				return 0;
  			}
  			hsb->s_gid = (gid_t)tmp;
  			break;
  		case opt_umask:
  			if (match_octal(&args[0], &tmp)) {

  				printk(KERN_ERR "hfs: umask requires a value
  ");

  				return 0;
  			}
  			hsb->s_file_umask = (umode_t)tmp;
  			hsb->s_dir_umask = (umode_t)tmp;
  			break;
  		case opt_file_umask:
  			if (match_octal(&args[0], &tmp)) {

  				printk(KERN_ERR "hfs: file_umask requires a value
  ");

  				return 0;
  			}
  			hsb->s_file_umask = (umode_t)tmp;
  			break;
  		case opt_dir_umask:
  			if (match_octal(&args[0], &tmp)) {

  				printk(KERN_ERR "hfs: dir_umask requires a value
  ");

  				return 0;
  			}
  			hsb->s_dir_umask = (umode_t)tmp;
  			break;
  		case opt_part:
  			if (match_int(&args[0], &hsb->part)) {

  				printk(KERN_ERR "hfs: part requires an argument
  ");

  				return 0;
  			}
  			break;
  		case opt_session:
  			if (match_int(&args[0], &hsb->session)) {

  				printk(KERN_ERR "hfs: session requires an argument
  ");

  				return 0;
  			}
  			break;
  		case opt_type:
  			if (match_fourchar(&args[0], &hsb->s_type)) {

  				printk(KERN_ERR "hfs: type requires a 4 character value
  ");

  				return 0;
  			}
  			break;
  		case opt_creator:
  			if (match_fourchar(&args[0], &hsb->s_creator)) {

  				printk(KERN_ERR "hfs: creator requires a 4 character value
  ");

  				return 0;
  			}
  			break;
  		case opt_quiet:
  			hsb->s_quiet = 1;
  			break;

  		case opt_codepage:
  			if (hsb->nls_disk) {

  				printk(KERN_ERR "hfs: unable to change codepage
  ");

  				return 0;
  			}
  			p = match_strdup(&args[0]);

  			if (p)
  				hsb->nls_disk = load_nls(p);

  			if (!hsb->nls_disk) {

  				printk(KERN_ERR "hfs: unable to load codepage \"%s\"
  ", p);

  				kfree(p);
  				return 0;
  			}
  			kfree(p);
  			break;
  		case opt_iocharset:
  			if (hsb->nls_io) {

  				printk(KERN_ERR "hfs: unable to change iocharset
  ");

  				return 0;
  			}
  			p = match_strdup(&args[0]);

  			if (p)
  				hsb->nls_io = load_nls(p);

  			if (!hsb->nls_io) {

  				printk(KERN_ERR "hfs: unable to load iocharset \"%s\"
  ", p);

  				kfree(p);
  				return 0;
  			}
  			kfree(p);
  			break;

  		default:
  			return 0;
  		}
  	}

  	if (hsb->nls_disk && !hsb->nls_io) {
  		hsb->nls_io = load_nls_default();
  		if (!hsb->nls_io) {

  			printk(KERN_ERR "hfs: unable to load default iocharset
  ");

  			return 0;
  		}
  	}

  	hsb->s_dir_umask &= 0777;
  	hsb->s_file_umask &= 0577;
  
  	return 1;
  }
  
  /*
   * hfs_read_super()
   *
   * This is the function that is responsible for mounting an HFS
   * filesystem.	It performs all the tasks necessary to get enough data
   * from the disk to read the root inode.  This includes parsing the
   * mount options, dealing with Macintosh partitions, reading the
   * superblock and the allocation bitmap blocks, calling
   * hfs_btree_init() to get the necessary data about the extents and
   * catalog B-trees and, finally, reading the root inode into memory.
   */
  static int hfs_fill_super(struct super_block *sb, void *data, int silent)
  {
  	struct hfs_sb_info *sbi;
  	struct hfs_find_data fd;
  	hfs_cat_rec rec;
  	struct inode *root_inode;
  	int res;

  	sbi = kzalloc(sizeof(struct hfs_sb_info), GFP_KERNEL);

  	if (!sbi)

  		return -ENOMEM;

  	sb->s_fs_info = sbi;

  
  	res = -EINVAL;
  	if (!parse_options((char *)data, sbi)) {

  		printk(KERN_ERR "hfs: unable to parse mount options.
  ");

  		goto bail;

  	}
  
  	sb->s_op = &hfs_super_operations;
  	sb->s_flags |= MS_NODIRATIME;

  	mutex_init(&sbi->bitmap_lock);

  
  	res = hfs_mdb_get(sb);
  	if (res) {
  		if (!silent)

  			printk(KERN_WARNING "hfs: can't find a HFS filesystem on dev %s.
  ",

  				hfs_mdb_name(sb));
  		res = -EINVAL;

  		goto bail;

  	}
  
  	/* try to get the root inode */
  	hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
  	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);

  	if (!res) {
  		if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
  			res =  -EIO;
  			goto bail;
  		}

  		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);

  	}

  	if (res) {
  		hfs_find_exit(&fd);
  		goto bail_no_root;
  	}

  	res = -EINVAL;

  	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
  	hfs_find_exit(&fd);
  	if (!root_inode)
  		goto bail_no_root;

  	sb->s_d_op = &hfs_dentry_operations;

  	res = -ENOMEM;

  	sb->s_root = d_alloc_root(root_inode);
  	if (!sb->s_root)
  		goto bail_iput;

  	/* everything's okay */
  	return 0;
  
  bail_iput:
  	iput(root_inode);
  bail_no_root:

  	printk(KERN_ERR "hfs: get root inode failed.
  ");

  bail:

  	hfs_mdb_put(sb);

  	return res;
  }

  static struct dentry *hfs_mount(struct file_system_type *fs_type,
  		      int flags, const char *dev_name, void *data)

  {

  	return mount_bdev(fs_type, flags, dev_name, data, hfs_fill_super);

  }
  
  static struct file_system_type hfs_fs_type = {
  	.owner		= THIS_MODULE,
  	.name		= "hfs",

  	.mount		= hfs_mount,

  	.kill_sb	= kill_block_super,
  	.fs_flags	= FS_REQUIRES_DEV,
  };

  static void hfs_init_once(void *p)

  {
  	struct hfs_inode_info *i = p;

  	inode_init_once(&i->vfs_inode);

  }
  
  static int __init init_hfs_fs(void)
  {
  	int err;
  
  	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
  		sizeof(struct hfs_inode_info), 0, SLAB_HWCACHE_ALIGN,

  		hfs_init_once);

  	if (!hfs_inode_cachep)
  		return -ENOMEM;
  	err = register_filesystem(&hfs_fs_type);
  	if (err)
  		kmem_cache_destroy(hfs_inode_cachep);
  	return err;
  }
  
  static void __exit exit_hfs_fs(void)
  {
  	unregister_filesystem(&hfs_fs_type);

  	kmem_cache_destroy(hfs_inode_cachep);

  }
  
  module_init(init_hfs_fs)
  module_exit(exit_hfs_fs)