int hfs_part_find(struct super_block *sb,
sector_t *part_start, sector_t *part_size)
{
struct buffer_head *bh;
__be16 *data;
int i, size, res;
res = -ENOENT;
bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);
if (!bh)
return -EIO;
switch (be16_to_cpu(*data)) {
case HFS_OLD_PMAP_MAGIC:
{
struct old_pmap *pm;
struct old_pmap_entry *p;
pm = (struct old_pmap *)bh->b_data;
p = pm->pdEntry;
size = 42;
for (i = 0; i < size; p++, i++) {
if (p->pdStart && p->pdSize &&
p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
(HFSPLUS_SB(sb).part < 0 || HFSPLUS_SB(sb).part == i)) {
*part_start += be32_to_cpu(p->pdStart);
*part_size = be32_to_cpu(p->pdSize);
res = 0;
}
}
break;
}
case HFS_NEW_PMAP_MAGIC:
{
struct new_pmap *pm;
pm = (struct new_pmap *)bh->b_data;
size = be32_to_cpu(pm->pmMapBlkCnt);
for (i = 0; i < size;) {
if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
(HFSPLUS_SB(sb).part < 0 || HFSPLUS_SB(sb).part == i)) {
*part_start += be32_to_cpu(pm->pmPyPartStart);
*part_size = be32_to_cpu(pm->pmPartBlkCnt);
res = 0;
break;
}
brelse(bh);
bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);
if (!bh)
return -EIO;
if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))
break;
}
break;
}
}
brelse(bh);
return res;
}
/*
* 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))
|| (attrib & cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT))) {
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 */
mdb->drAtrb = attrib & cpu_to_be16(~HFS_SB_ATTRIB_UNMNT);
mdb->drAtrb = attrib | cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT);
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;
}
