[mirror_ubuntu-bionic-kernel.git] / fs / hfs / mdb.c

/*
 *  linux/fs/hfs/mdb.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 functions for reading/writing the MDB.
 */

#include <linux/cdrom.h>
#include <linux/genhd.h>

#include "hfs_fs.h"
#include "btree.h"

/*================ File-local data types ================*/

/*
 * The HFS Master Directory Block (MDB).
 *
 * Also known as the Volume Information Block (VIB), this structure is
 * the HFS equivalent of a superblock.
 *
 * Reference: _Inside Macintosh: Files_ pages 2-59 through 2-62
 *
 * modified for HFS Extended
 */

static int hfs_get_last_session(struct super_block *sb,
				sector_t *start, sector_t *size)
{
	struct cdrom_multisession ms_info;
	struct cdrom_tocentry te;
	int res;

	/* default values */
	*start = 0;
	*size = sb->s_bdev->bd_inode->i_size >> 9;

	if (HFS_SB(sb)->session >= 0) {
		te.cdte_track = HFS_SB(sb)->session;
		te.cdte_format = CDROM_LBA;
		res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te);
		if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
			*start = (sector_t)te.cdte_addr.lba << 2;
			return 0;
		}
		printk(KERN_ERR "HFS: Invalid session number or type of track\n");
		return -EINVAL;
	}
	ms_info.addr_format = CDROM_LBA;
	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
	if (!res && ms_info.xa_flag)
		*start = (sector_t)ms_info.addr.lba << 2;
	return 0;
}

/*
 * hfs_mdb_get()
 *
 * Build the in-core MDB for a filesystem, including
 * the B-trees and the volume bitmap.
 */
int hfs_mdb_get(struct super_block *sb)
{
	struct buffer_head *bh;
	struct hfs_mdb *mdb, *mdb2;
	unsigned int block;
	char *ptr;
	int off2, len, size, sect;
	sector_t part_start, part_size;
	loff_t off;
	__be16 attrib;

	/* set the device driver to 512-byte blocks */
	size = sb_min_blocksize(sb, HFS_SECTOR_SIZE);
	if (!size)
		return -EINVAL;

	if (hfs_get_last_session(sb, &part_start, &part_size))
		return -EINVAL;
	while (1) {
		/* See if this is an HFS filesystem */
		bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
		if (!bh)
			goto out;

		if (mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC))
			break;
		brelse(bh);

		/* check for a partition block
		 * (should do this only for cdrom/loop though)
		 */
		if (hfs_part_find(sb, &part_start, &part_size))
			goto out;
	}

	HFS_SB(sb)->alloc_blksz = size = be32_to_cpu(mdb->drAlBlkSiz);
	if (!size || (size & (HFS_SECTOR_SIZE - 1))) {
		hfs_warn("hfs_fs: bad allocation block size %d\n", size);
		goto out_bh;
	}

	size = min(HFS_SB(sb)->alloc_blksz, (u32)PAGE_SIZE);
	/* size must be a multiple of 512 */
	while (size & (size - 1))
		size -= HFS_SECTOR_SIZE;
	sect = be16_to_cpu(mdb->drAlBlSt) + part_start;
	/* align block size to first sector */
	while (sect & ((size - 1) >> HFS_SECTOR_SIZE_BITS))
		size >>= 1;
	/* align block size to weird alloc size */
	while (HFS_SB(sb)->alloc_blksz & (size - 1))
		size >>= 1;
	brelse(bh);
	if (!sb_set_blocksize(sb, size)) {
		printk("hfs_fs: unable to set blocksize to %u\n", size);
		goto out;
	}

	bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
	if (!bh)
		goto out;
	if (mdb->drSigWord != cpu_to_be16(HFS_SUPER_MAGIC))
		goto out_bh;

	HFS_SB(sb)->mdb_bh = bh;
	HFS_SB(sb)->mdb = mdb;

	/* These parameters are read from the MDB, and never written */
	HFS_SB(sb)->part_start = part_start;
	HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks);
	HFS_SB(sb)->fs_div = HFS_SB(sb)->alloc_blksz >> sb->s_blocksize_bits;
	HFS_SB(sb)->clumpablks = be32_to_cpu(mdb->drClpSiz) /
				 HFS_SB(sb)->alloc_blksz;
	if (!HFS_SB(sb)->clumpablks)
		HFS_SB(sb)->clumpablks = 1;
	HFS_SB(sb)->fs_start = (be16_to_cpu(mdb->drAlBlSt) + part_start) >>
			       (sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS);

	/* These parameters are read from and written to the MDB */
	HFS_SB(sb)->free_ablocks = be16_to_cpu(mdb->drFreeBks);
	HFS_SB(sb)->next_id = be32_to_cpu(mdb->drNxtCNID);
	HFS_SB(sb)->root_files = be16_to_cpu(mdb->drNmFls);
	HFS_SB(sb)->root_dirs = be16_to_cpu(mdb->drNmRtDirs);
	HFS_SB(sb)->file_count = be32_to_cpu(mdb->drFilCnt);
	HFS_SB(sb)->folder_count = be32_to_cpu(mdb->drDirCnt);

	/* TRY to get the alternate (backup) MDB. */
	sect = part_start + part_size - 2;
	bh = sb_bread512(sb, sect, mdb2);
	if (bh) {
		if (mdb2->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) {
			HFS_SB(sb)->alt_mdb_bh = bh;
			HFS_SB(sb)->alt_mdb = mdb2;
		} else
			brelse(bh);
	}

	if (!HFS_SB(sb)->alt_mdb) {
		hfs_warn("hfs_fs: unable to locate alternate MDB\n");
		hfs_warn("hfs_fs: continuing without an alternate MDB\n");
	}

	HFS_SB(sb)->bitmap = (__be32 *)__get_free_pages(GFP_KERNEL, PAGE_SIZE < 8192 ? 1 : 0);
	if (!HFS_SB(sb)->bitmap)
		goto out;

	/* read in the bitmap */
	block = be16_to_cpu(mdb->drVBMSt) + part_start;
	off = (loff_t)block << HFS_SECTOR_SIZE_BITS;
	size = (HFS_SB(sb)->fs_ablocks + 8) / 8;
	ptr = (u8 *)HFS_SB(sb)->bitmap;
	while (size) {
		bh = sb_bread(sb, off >> sb->s_blocksize_bits);
		if (!bh) {
			hfs_warn("hfs_fs: unable to read volume bitmap\n");
			goto out;
		}
		off2 = off & (sb->s_blocksize - 1);
		len = min((int)sb->s_blocksize - off2, size);
		memcpy(ptr, bh->b_data + off2, len);
		brelse(bh);
		ptr += len;
		off += len;
		size -= len;
	}

	HFS_SB(sb)->ext_tree = hfs_btree_open(sb, HFS_EXT_CNID, hfs_ext_keycmp);
	if (!HFS_SB(sb)->ext_tree) {
		hfs_warn("hfs_fs: unable to open extent tree\n");
		goto out;
	}
	HFS_SB(sb)->cat_tree = hfs_btree_open(sb, HFS_CAT_CNID, hfs_cat_keycmp);
	if (!HFS_SB(sb)->cat_tree) {
		hfs_warn("hfs_fs: unable to open catalog tree\n");
		goto out;
	}

	attrib = mdb->drAtrb;
	if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
		hfs_warn("HFS-fs warning: Filesystem was not cleanly unmounted, "
			 "running fsck.hfs is recommended.  mounting read-only.\n");
		sb->s_flags |= MS_RDONLY;
	}
	if ((attrib & cpu_to_be16(HFS_SB_ATTRIB_SLOCK))) {
		hfs_warn("HFS-fs: Filesystem is marked locked, mounting read-only.\n");
		sb->s_flags |= MS_RDONLY;
	}
	if (!(sb->s_flags & MS_RDONLY)) {
		/* Mark the volume uncleanly unmounted in case we crash */
		attrib &= cpu_to_be16(~HFS_SB_ATTRIB_UNMNT);
		attrib |= cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT);
		mdb->drAtrb = attrib;
		mdb->drWrCnt = cpu_to_be32(be32_to_cpu(mdb->drWrCnt) + 1);
		mdb->drLsMod = hfs_mtime();

		mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
		hfs_buffer_sync(HFS_SB(sb)->mdb_bh);
	}

	return 0;

out_bh:
	brelse(bh);
out:
	hfs_mdb_put(sb);
	return -EIO;
}

/*
 * hfs_mdb_commit()
 *
 * Description:
 *   This updates the MDB on disk (look also at hfs_write_super()).
 *   It does not check, if the superblock has been modified, or
 *   if the filesystem has been mounted read-only. It is mainly
 *   called by hfs_write_super() and hfs_btree_extend().
 * Input Variable(s):
 *   struct hfs_mdb *mdb: Pointer to the hfs MDB
 *   int backup;
 * Output Variable(s):
 *   NONE
 * Returns:
 *   void
 * Preconditions:
 *   'mdb' points to a "valid" (struct hfs_mdb).
 * Postconditions:
 *   The HFS MDB and on disk will be updated, by copying the possibly
 *   modified fields from the in memory MDB (in native byte order) to
 *   the disk block buffer.
 *   If 'backup' is non-zero then the alternate MDB is also written
 *   and the function doesn't return until it is actually on disk.
 */
void hfs_mdb_commit(struct super_block *sb)
{
	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;

	if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
		/* These parameters may have been modified, so write them back */
		mdb->drLsMod = hfs_mtime();
		mdb->drFreeBks = cpu_to_be16(HFS_SB(sb)->free_ablocks);
		mdb->drNxtCNID = cpu_to_be32(HFS_SB(sb)->next_id);
		mdb->drNmFls = cpu_to_be16(HFS_SB(sb)->root_files);
		mdb->drNmRtDirs = cpu_to_be16(HFS_SB(sb)->root_dirs);
		mdb->drFilCnt = cpu_to_be32(HFS_SB(sb)->file_count);
		mdb->drDirCnt = cpu_to_be32(HFS_SB(sb)->folder_count);

		/* write MDB to disk */
		mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
	}

	/* write the backup MDB, not returning until it is written.
	 * we only do this when either the catalog or extents overflow
	 * files grow. */
	if (test_and_clear_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags) &&
	    HFS_SB(sb)->alt_mdb) {
		hfs_inode_write_fork(HFS_SB(sb)->ext_tree->inode, mdb->drXTExtRec,
				     &mdb->drXTFlSize, NULL);
		hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
				     &mdb->drCTFlSize, NULL);
		memcpy(HFS_SB(sb)->alt_mdb, HFS_SB(sb)->mdb, HFS_SECTOR_SIZE);
		HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
		HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
		mark_buffer_dirty(HFS_SB(sb)->alt_mdb_bh);
		hfs_buffer_sync(HFS_SB(sb)->alt_mdb_bh);
	}

	if (test_and_clear_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags)) {
		struct buffer_head *bh;
		sector_t block;
		char *ptr;
		int off, size, len;

		block = be16_to_cpu(HFS_SB(sb)->mdb->drVBMSt) + HFS_SB(sb)->part_start;
		off = (block << HFS_SECTOR_SIZE_BITS) & (sb->s_blocksize - 1);
		block >>= sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS;
		size = (HFS_SB(sb)->fs_ablocks + 7) / 8;
		ptr = (u8 *)HFS_SB(sb)->bitmap;
		while (size) {
			bh = sb_bread(sb, block);
			if (!bh) {
				hfs_warn("hfs_fs: unable to read volume bitmap\n");
				break;
			}
			len = min((int)sb->s_blocksize - off, size);
			memcpy(bh->b_data + off, ptr, len);
			mark_buffer_dirty(bh);
			brelse(bh);
			block++;
			off = 0;
			ptr += len;
			size -= len;
		}
	}
}

void hfs_mdb_close(struct super_block *sb)
{
	/* update volume attributes */
	if (sb->s_flags & MS_RDONLY)
		return;
	HFS_SB(sb)->mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
	HFS_SB(sb)->mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
	mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
}

/*
 * hfs_mdb_put()
 *
 * Release the resources associated with the in-core MDB.  */
void hfs_mdb_put(struct super_block *sb)
{
	if (!HFS_SB(sb))
		return;
	/* free the B-trees */
	hfs_btree_close(HFS_SB(sb)->ext_tree);
	hfs_btree_close(HFS_SB(sb)->cat_tree);

	/* free the buffers holding the primary and alternate MDBs */
	brelse(HFS_SB(sb)->mdb_bh);
	brelse(HFS_SB(sb)->alt_mdb_bh);

	kfree(HFS_SB(sb));
	sb->s_fs_info = NULL;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/hfs/mdb.c
	3	*
	4	* Copyright (C) 1995-1997 Paul H. Hargrove
	5	* (C) 2003 Ardis Technologies <roman@ardistech.com>
	6	* This file may be distributed under the terms of the GNU General Public License.
	7	*
	8	* This file contains functions for reading/writing the MDB.
	9	*/
	10
	11	#include <linux/cdrom.h>
	12	#include <linux/genhd.h>
	13
	14	#include "hfs_fs.h"
	15	#include "btree.h"
	16
	17	/================ File-local data types ================/
	18
	19	/*
	20	* The HFS Master Directory Block (MDB).
	21	*
	22	* Also known as the Volume Information Block (VIB), this structure is
	23	* the HFS equivalent of a superblock.
	24	*
	25	* Reference: _Inside Macintosh: Files_ pages 2-59 through 2-62
	26	*
	27	* modified for HFS Extended
	28	*/
	29
	30	static int hfs_get_last_session(struct super_block *sb,
	31	sector_t start, sector_t size)
	32	{
	33	struct cdrom_multisession ms_info;
	34	struct cdrom_tocentry te;
	35	int res;
	36
	37	/* default values */
	38	*start = 0;
	39	*size = sb->s_bdev->bd_inode->i_size >> 9;
	40
	41	if (HFS_SB(sb)->session >= 0) {
	42	te.cdte_track = HFS_SB(sb)->session;
	43	te.cdte_format = CDROM_LBA;
	44	res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te);
	45	if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
	46	*start = (sector_t)te.cdte_addr.lba << 2;
	47	return 0;
	48	}
	49	printk(KERN_ERR "HFS: Invalid session number or type of track\n");
	50	return -EINVAL;
	51	}
	52	ms_info.addr_format = CDROM_LBA;
	53	res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
	54	if (!res && ms_info.xa_flag)
	55	*start = (sector_t)ms_info.addr.lba << 2;
	56	return 0;
	57	}
	58
	59	/*
	60	* hfs_mdb_get()
	61	*
	62	* Build the in-core MDB for a filesystem, including
	63	* the B-trees and the volume bitmap.
	64	*/
65	int hfs_mdb_get(struct super_block *sb)
66	{
67	struct buffer_head *bh;
68	struct hfs_mdb mdb, mdb2;
69	unsigned int block;
70	char *ptr;
71	int off2, len, size, sect;
72	sector_t part_start, part_size;
73	loff_t off;
74	__be16 attrib;
75
76	/* set the device driver to 512-byte blocks */
77	size = sb_min_blocksize(sb, HFS_SECTOR_SIZE);
78	if (!size)
79	return -EINVAL;
80
81	if (hfs_get_last_session(sb, &part_start, &part_size))
82	return -EINVAL;
83	while (1) {
84	/* See if this is an HFS filesystem */
85	bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
86	if (!bh)
87	goto out;
88
89	if (mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC))
90	break;
91	brelse(bh);
92
93	/* check for a partition block
94	* (should do this only for cdrom/loop though)
95	*/
96	if (hfs_part_find(sb, &part_start, &part_size))
97	goto out;
98	}
99
100	HFS_SB(sb)->alloc_blksz = size = be32_to_cpu(mdb->drAlBlkSiz);
101	if (!size \|\| (size & (HFS_SECTOR_SIZE - 1))) {
102	hfs_warn("hfs_fs: bad allocation block size %d\n", size);
103	goto out_bh;
104	}
105
106	size = min(HFS_SB(sb)->alloc_blksz, (u32)PAGE_SIZE);
107	/* size must be a multiple of 512 */
108	while (size & (size - 1))
109	size -= HFS_SECTOR_SIZE;
110	sect = be16_to_cpu(mdb->drAlBlSt) + part_start;
111	/* align block size to first sector */
112	while (sect & ((size - 1) >> HFS_SECTOR_SIZE_BITS))
113	size >>= 1;
114	/* align block size to weird alloc size */
115	while (HFS_SB(sb)->alloc_blksz & (size - 1))
116	size >>= 1;
117	brelse(bh);
118	if (!sb_set_blocksize(sb, size)) {
119	printk("hfs_fs: unable to set blocksize to %u\n", size);
120	goto out;
121	}
122
123	bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
124	if (!bh)
125	goto out;
126	if (mdb->drSigWord != cpu_to_be16(HFS_SUPER_MAGIC))
127	goto out_bh;
128
129	HFS_SB(sb)->mdb_bh = bh;
130	HFS_SB(sb)->mdb = mdb;
131
132	/* These parameters are read from the MDB, and never written */
133	HFS_SB(sb)->part_start = part_start;
134	HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks);
135	HFS_SB(sb)->fs_div = HFS_SB(sb)->alloc_blksz >> sb->s_blocksize_bits;
136	HFS_SB(sb)->clumpablks = be32_to_cpu(mdb->drClpSiz) /
137	HFS_SB(sb)->alloc_blksz;
138	if (!HFS_SB(sb)->clumpablks)
139	HFS_SB(sb)->clumpablks = 1;
140	HFS_SB(sb)->fs_start = (be16_to_cpu(mdb->drAlBlSt) + part_start) >>
141	(sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS);
142
143	/* These parameters are read from and written to the MDB */
144	HFS_SB(sb)->free_ablocks = be16_to_cpu(mdb->drFreeBks);
145	HFS_SB(sb)->next_id = be32_to_cpu(mdb->drNxtCNID);
146	HFS_SB(sb)->root_files = be16_to_cpu(mdb->drNmFls);
147	HFS_SB(sb)->root_dirs = be16_to_cpu(mdb->drNmRtDirs);
148	HFS_SB(sb)->file_count = be32_to_cpu(mdb->drFilCnt);
149	HFS_SB(sb)->folder_count = be32_to_cpu(mdb->drDirCnt);
150
151	/* TRY to get the alternate (backup) MDB. */
152	sect = part_start + part_size - 2;
153	bh = sb_bread512(sb, sect, mdb2);
154	if (bh) {
155	if (mdb2->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) {
156	HFS_SB(sb)->alt_mdb_bh = bh;
157	HFS_SB(sb)->alt_mdb = mdb2;
158	} else
159	brelse(bh);
160	}
161
162	if (!HFS_SB(sb)->alt_mdb) {
163	hfs_warn("hfs_fs: unable to locate alternate MDB\n");
164	hfs_warn("hfs_fs: continuing without an alternate MDB\n");
165	}
166
167	HFS_SB(sb)->bitmap = (__be32 *)__get_free_pages(GFP_KERNEL, PAGE_SIZE < 8192 ? 1 : 0);
168	if (!HFS_SB(sb)->bitmap)
169	goto out;
170
171	/* read in the bitmap */
172	block = be16_to_cpu(mdb->drVBMSt) + part_start;
173	off = (loff_t)block << HFS_SECTOR_SIZE_BITS;
174	size = (HFS_SB(sb)->fs_ablocks + 8) / 8;
175	ptr = (u8 *)HFS_SB(sb)->bitmap;
176	while (size) {
177	bh = sb_bread(sb, off >> sb->s_blocksize_bits);
178	if (!bh) {
179	hfs_warn("hfs_fs: unable to read volume bitmap\n");
180	goto out;
181	}
182	off2 = off & (sb->s_blocksize - 1);
183	len = min((int)sb->s_blocksize - off2, size);
184	memcpy(ptr, bh->b_data + off2, len);
185	brelse(bh);
186	ptr += len;
187	off += len;
188	size -= len;
189	}
190
191	HFS_SB(sb)->ext_tree = hfs_btree_open(sb, HFS_EXT_CNID, hfs_ext_keycmp);
192	if (!HFS_SB(sb)->ext_tree) {
193	hfs_warn("hfs_fs: unable to open extent tree\n");
194	goto out;
195	}
196	HFS_SB(sb)->cat_tree = hfs_btree_open(sb, HFS_CAT_CNID, hfs_cat_keycmp);
197	if (!HFS_SB(sb)->cat_tree) {
198	hfs_warn("hfs_fs: unable to open catalog tree\n");
199	goto out;
200	}
201
202	attrib = mdb->drAtrb;
203	if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
204	hfs_warn("HFS-fs warning: Filesystem was not cleanly unmounted, "
205	"running fsck.hfs is recommended. mounting read-only.\n");
206	sb->s_flags \|= MS_RDONLY;
207	}
208	if ((attrib & cpu_to_be16(HFS_SB_ATTRIB_SLOCK))) {
209	hfs_warn("HFS-fs: Filesystem is marked locked, mounting read-only.\n");
210	sb->s_flags \|= MS_RDONLY;
211	}
212	if (!(sb->s_flags & MS_RDONLY)) {
213	/* Mark the volume uncleanly unmounted in case we crash */
214	attrib &= cpu_to_be16(~HFS_SB_ATTRIB_UNMNT);
215	attrib \|= cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT);
216	mdb->drAtrb = attrib;
217	mdb->drWrCnt = cpu_to_be32(be32_to_cpu(mdb->drWrCnt) + 1);
218	mdb->drLsMod = hfs_mtime();
219
220	mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
221	hfs_buffer_sync(HFS_SB(sb)->mdb_bh);
222	}
223
224	return 0;
225
226	out_bh:
227	brelse(bh);
228	out:
229	hfs_mdb_put(sb);
230	return -EIO;
231	}
232
233	/*
234	* hfs_mdb_commit()
235	*
236	* Description:
237	* This updates the MDB on disk (look also at hfs_write_super()).
238	* It does not check, if the superblock has been modified, or
239	* if the filesystem has been mounted read-only. It is mainly
240	* called by hfs_write_super() and hfs_btree_extend().
241	* Input Variable(s):
242	* struct hfs_mdb *mdb: Pointer to the hfs MDB
243	* int backup;
244	* Output Variable(s):
245	* NONE
246	* Returns:
247	* void
248	* Preconditions:
249	* 'mdb' points to a "valid" (struct hfs_mdb).
250	* Postconditions:
251	* The HFS MDB and on disk will be updated, by copying the possibly
252	* modified fields from the in memory MDB (in native byte order) to
253	* the disk block buffer.
254	* If 'backup' is non-zero then the alternate MDB is also written
255	* and the function doesn't return until it is actually on disk.
256	*/
257	void hfs_mdb_commit(struct super_block *sb)
258	{
259	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
260
261	if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
262	/* These parameters may have been modified, so write them back */
263	mdb->drLsMod = hfs_mtime();
264	mdb->drFreeBks = cpu_to_be16(HFS_SB(sb)->free_ablocks);
265	mdb->drNxtCNID = cpu_to_be32(HFS_SB(sb)->next_id);
266	mdb->drNmFls = cpu_to_be16(HFS_SB(sb)->root_files);
267	mdb->drNmRtDirs = cpu_to_be16(HFS_SB(sb)->root_dirs);
268	mdb->drFilCnt = cpu_to_be32(HFS_SB(sb)->file_count);
269	mdb->drDirCnt = cpu_to_be32(HFS_SB(sb)->folder_count);
270
271	/* write MDB to disk */
272	mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
273	}
274
275	/* write the backup MDB, not returning until it is written.
276	* we only do this when either the catalog or extents overflow
277	* files grow. */
278	if (test_and_clear_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags) &&
279	HFS_SB(sb)->alt_mdb) {
280	hfs_inode_write_fork(HFS_SB(sb)->ext_tree->inode, mdb->drXTExtRec,
281	&mdb->drXTFlSize, NULL);
282	hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
283	&mdb->drCTFlSize, NULL);
284	memcpy(HFS_SB(sb)->alt_mdb, HFS_SB(sb)->mdb, HFS_SECTOR_SIZE);
285	HFS_SB(sb)->alt_mdb->drAtrb \|= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
286	HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
287	mark_buffer_dirty(HFS_SB(sb)->alt_mdb_bh);
288	hfs_buffer_sync(HFS_SB(sb)->alt_mdb_bh);
289	}
290
291	if (test_and_clear_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags)) {
292	struct buffer_head *bh;
293	sector_t block;
294	char *ptr;
295	int off, size, len;
296
297	block = be16_to_cpu(HFS_SB(sb)->mdb->drVBMSt) + HFS_SB(sb)->part_start;
298	off = (block << HFS_SECTOR_SIZE_BITS) & (sb->s_blocksize - 1);
299	block >>= sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS;
300	size = (HFS_SB(sb)->fs_ablocks + 7) / 8;
301	ptr = (u8 *)HFS_SB(sb)->bitmap;
302	while (size) {
303	bh = sb_bread(sb, block);
304	if (!bh) {
305	hfs_warn("hfs_fs: unable to read volume bitmap\n");
306	break;
307	}
308	len = min((int)sb->s_blocksize - off, size);
309	memcpy(bh->b_data + off, ptr, len);
310	mark_buffer_dirty(bh);
311	brelse(bh);
312	block++;
313	off = 0;
314	ptr += len;
315	size -= len;
316	}
317	}
318	}
319
320	void hfs_mdb_close(struct super_block *sb)
321	{
322	/* update volume attributes */
323	if (sb->s_flags & MS_RDONLY)
324	return;
325	HFS_SB(sb)->mdb->drAtrb \|= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
326	HFS_SB(sb)->mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
327	mark_buffer_dirty(HFS_SB(sb)->mdb_bh);
328	}
329
330	/*
331	* hfs_mdb_put()
332	*
333	* Release the resources associated with the in-core MDB. */
334	void hfs_mdb_put(struct super_block *sb)
335	{
945b0920 CL	336	if (!HFS_SB(sb))
945b0920 CL	337	return;
1da177e4 LT	338	/* free the B-trees */
	339	hfs_btree_close(HFS_SB(sb)->ext_tree);
	340	hfs_btree_close(HFS_SB(sb)->cat_tree);
	341
	342	/* free the buffers holding the primary and alternate MDBs */
	343	brelse(HFS_SB(sb)->mdb_bh);
	344	brelse(HFS_SB(sb)->alt_mdb_bh);
945b0920 CL	345
	346	kfree(HFS_SB(sb));
	347	sb->s_fs_info = NULL;
1da177e4	348	}