/*
* 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;
}
/* Takes in super block, returns true if good data read */
int hfsplus_read_wrapper(struct super_block *sb)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_wd wd;
sector_t part_start, part_size;
u32 blocksize;
int error = 0;
error = -EINVAL;
blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
if (!blocksize)
goto out;
if (hfsplus_get_last_session(sb, &part_start, &part_size))
goto out;
error = -ENOMEM;
sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
if (!sbi->s_vhdr_buf)
goto out;
sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
if (!sbi->s_backup_vhdr_buf)
goto out_free_vhdr;
reread:
error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR,
sbi->s_vhdr_buf, (void **)&sbi->s_vhdr,
READ);
if (error)
goto out_free_backup_vhdr;
error = -EINVAL;
switch (sbi->s_vhdr->signature) {
case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
/*FALLTHRU*/
case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
break;
case cpu_to_be16(HFSP_WRAP_MAGIC):
if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
goto out_free_backup_vhdr;
wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
part_start += (sector_t)wd.ablk_start +
(sector_t)wd.embed_start * wd.ablk_size;
part_size = (sector_t)wd.embed_count * wd.ablk_size;
goto reread;
default:
/*
* Check for a partition block.
*
* (should do this only for cdrom/loop though)
*/
if (hfs_part_find(sb, &part_start, &part_size))
goto out_free_backup_vhdr;
goto reread;
}
error = hfsplus_submit_bio(sb, part_start + part_size - 2,
sbi->s_backup_vhdr_buf,
(void **)&sbi->s_backup_vhdr, READ);
if (error)
goto out_free_backup_vhdr;
error = -EINVAL;
if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
pr_warn("invalid secondary volume header\n");
goto out_free_backup_vhdr;
}
blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
/*
* Block size must be at least as large as a sector and a multiple of 2.
*/
if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
goto out_free_backup_vhdr;
sbi->alloc_blksz = blocksize;
sbi->alloc_blksz_shift = 0;
while ((blocksize >>= 1) != 0)
sbi->alloc_blksz_shift++;
blocksize = min(sbi->alloc_blksz, (u32)PAGE_SIZE);
/*
* Align block size to block offset.
*/
while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
blocksize >>= 1;
if (sb_set_blocksize(sb, blocksize) != blocksize) {
pr_err("unable to set blocksize to %u!\n", blocksize);
goto out_free_backup_vhdr;
}
sbi->blockoffset =
part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
sbi->part_start = part_start;
sbi->sect_count = part_size;
sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
return 0;
out_free_backup_vhdr:
kfree(sbi->s_backup_vhdr_buf);
out_free_vhdr:
kfree(sbi->s_vhdr_buf);
out:
return error;
}
/*
* 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.
*/
struct super_block *hfs_read_super(struct super_block *s, void *data,
int silent)
{
struct hfs_mdb *mdb;
struct hfs_cat_key key;
kdev_t dev = s->s_dev;
hfs_s32 part_size, part_start;
struct inode *root_inode;
int part;
if (!parse_options((char *)data, HFS_SB(s), &part)) {
hfs_warn("hfs_fs: unable to parse mount options.\n");
goto bail3;
}
/* set the device driver to 512-byte blocks */
set_blocksize(dev, HFS_SECTOR_SIZE);
s->s_blocksize_bits = HFS_SECTOR_SIZE_BITS;
s->s_blocksize = HFS_SECTOR_SIZE;
#ifdef CONFIG_MAC_PARTITION
/* check to see if we're in a partition */
mdb = hfs_mdb_get(s, s->s_flags & MS_RDONLY, 0);
/* erk. try parsing the partition table ourselves */
if (!mdb) {
if (hfs_part_find(s, part, silent, &part_size, &part_start)) {
goto bail2;
}
mdb = hfs_mdb_get(s, s->s_flags & MS_RDONLY, part_start);
}
#else
if (hfs_part_find(s, part, silent, &part_size, &part_start)) {
goto bail2;
}
mdb = hfs_mdb_get(s, s->s_flags & MS_RDONLY, part_start);
#endif
if (!mdb) {
if (!silent) {
hfs_warn("VFS: Can't find a HFS filesystem on dev %s.\n",
kdevname(dev));
}
goto bail2;
}
HFS_SB(s)->s_mdb = mdb;
if (HFS_ITYPE(mdb->next_id) != 0) {
hfs_warn("hfs_fs: too many files.\n");
goto bail1;
}
s->s_magic = HFS_SUPER_MAGIC;
s->s_op = &hfs_super_operations;
/* try to get the root inode */
hfs_cat_build_key(htonl(HFS_POR_CNID),
(struct hfs_name *)(mdb->vname), &key);
root_inode = hfs_iget(hfs_cat_get(mdb, &key), HFS_ITYPE_NORM, NULL);
if (!root_inode)
goto bail_no_root;
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto bail_no_root;
/* fix up pointers. */
HFS_I(root_inode)->entry->sys_entry[HFS_ITYPE_TO_INT(HFS_ITYPE_NORM)] =
s->s_root;
s->s_root->d_op = &hfs_dentry_operations;
/* everything's okay */
return s;
bail_no_root:
hfs_warn("hfs_fs: get root inode failed.\n");
iput(root_inode);
bail1:
hfs_mdb_put(mdb, s->s_flags & MS_RDONLY);
bail2:
set_blocksize(dev, BLOCK_SIZE);
bail3:
return NULL;
}
