11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/fs/hfsplus/wrapper.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 2001 51da177e4SLinus Torvalds * Brad Boyer (flar@allandria.com) 61da177e4SLinus Torvalds * (C) 2003 Ardis Technologies <roman@ardistech.com> 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * Handling of HFS wrappers around HFS+ volumes 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 111da177e4SLinus Torvalds #include <linux/fs.h> 121da177e4SLinus Torvalds #include <linux/blkdev.h> 131da177e4SLinus Torvalds #include <linux/cdrom.h> 141da177e4SLinus Torvalds #include <linux/genhd.h> 151da177e4SLinus Torvalds #include <asm/unaligned.h> 161da177e4SLinus Torvalds 171da177e4SLinus Torvalds #include "hfsplus_fs.h" 181da177e4SLinus Torvalds #include "hfsplus_raw.h" 191da177e4SLinus Torvalds 201da177e4SLinus Torvalds struct hfsplus_wd { 211da177e4SLinus Torvalds u32 ablk_size; 221da177e4SLinus Torvalds u16 ablk_start; 231da177e4SLinus Torvalds u16 embed_start; 241da177e4SLinus Torvalds u16 embed_count; 251da177e4SLinus Torvalds }; 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd) 281da177e4SLinus Torvalds { 291da177e4SLinus Torvalds u32 extent; 301da177e4SLinus Torvalds u16 attrib; 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds if (be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG)) != HFSPLUS_VOLHEAD_SIG) 331da177e4SLinus Torvalds return 0; 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB)); 361da177e4SLinus Torvalds if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) || 371da177e4SLinus Torvalds !(attrib & HFSP_WRAP_ATTRIB_SPARED)) 381da177e4SLinus Torvalds return 0; 391da177e4SLinus Torvalds 401da177e4SLinus Torvalds wd->ablk_size = be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE)); 411da177e4SLinus Torvalds if (wd->ablk_size < HFSPLUS_SECTOR_SIZE) 421da177e4SLinus Torvalds return 0; 431da177e4SLinus Torvalds if (wd->ablk_size % HFSPLUS_SECTOR_SIZE) 441da177e4SLinus Torvalds return 0; 451da177e4SLinus Torvalds wd->ablk_start = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART)); 461da177e4SLinus Torvalds 471da177e4SLinus Torvalds extent = be32_to_cpu(get_unaligned((__be32 *)(bufptr + HFSP_WRAPOFF_EMBEDEXT))); 481da177e4SLinus Torvalds wd->embed_start = (extent >> 16) & 0xFFFF; 491da177e4SLinus Torvalds wd->embed_count = extent & 0xFFFF; 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds return 1; 521da177e4SLinus Torvalds } 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds static int hfsplus_get_last_session(struct super_block *sb, 551da177e4SLinus Torvalds sector_t *start, sector_t *size) 561da177e4SLinus Torvalds { 571da177e4SLinus Torvalds struct cdrom_multisession ms_info; 581da177e4SLinus Torvalds struct cdrom_tocentry te; 591da177e4SLinus Torvalds int res; 601da177e4SLinus Torvalds 611da177e4SLinus Torvalds /* default values */ 621da177e4SLinus Torvalds *start = 0; 631da177e4SLinus Torvalds *size = sb->s_bdev->bd_inode->i_size >> 9; 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds if (HFSPLUS_SB(sb).session >= 0) { 661da177e4SLinus Torvalds te.cdte_track = HFSPLUS_SB(sb).session; 671da177e4SLinus Torvalds te.cdte_format = CDROM_LBA; 681da177e4SLinus Torvalds res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te); 691da177e4SLinus Torvalds if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) { 701da177e4SLinus Torvalds *start = (sector_t)te.cdte_addr.lba << 2; 711da177e4SLinus Torvalds return 0; 721da177e4SLinus Torvalds } 73634725a9SRoman Zippel printk(KERN_ERR "hfs: invalid session number or type of track\n"); 741da177e4SLinus Torvalds return -EINVAL; 751da177e4SLinus Torvalds } 761da177e4SLinus Torvalds ms_info.addr_format = CDROM_LBA; 771da177e4SLinus Torvalds res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info); 781da177e4SLinus Torvalds if (!res && ms_info.xa_flag) 791da177e4SLinus Torvalds *start = (sector_t)ms_info.addr.lba << 2; 801da177e4SLinus Torvalds return 0; 811da177e4SLinus Torvalds } 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds /* Find the volume header and fill in some minimum bits in superblock */ 841da177e4SLinus Torvalds /* Takes in super block, returns true if good data read */ 851da177e4SLinus Torvalds int hfsplus_read_wrapper(struct super_block *sb) 861da177e4SLinus Torvalds { 871da177e4SLinus Torvalds struct buffer_head *bh; 881da177e4SLinus Torvalds struct hfsplus_vh *vhdr; 891da177e4SLinus Torvalds struct hfsplus_wd wd; 901da177e4SLinus Torvalds sector_t part_start, part_size; 911da177e4SLinus Torvalds u32 blocksize; 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE); 941da177e4SLinus Torvalds if (!blocksize) 951da177e4SLinus Torvalds return -EINVAL; 961da177e4SLinus Torvalds 971da177e4SLinus Torvalds if (hfsplus_get_last_session(sb, &part_start, &part_size)) 981da177e4SLinus Torvalds return -EINVAL; 991da177e4SLinus Torvalds while (1) { 1001da177e4SLinus Torvalds bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr); 1011da177e4SLinus Torvalds if (!bh) 1021da177e4SLinus Torvalds return -EIO; 1031da177e4SLinus Torvalds 1041da177e4SLinus Torvalds if (vhdr->signature == cpu_to_be16(HFSP_WRAP_MAGIC)) { 1051da177e4SLinus Torvalds if (!hfsplus_read_mdb(vhdr, &wd)) 1061da177e4SLinus Torvalds goto error; 1071da177e4SLinus Torvalds wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT; 1081da177e4SLinus Torvalds part_start += wd.ablk_start + wd.embed_start * wd.ablk_size; 1091da177e4SLinus Torvalds part_size = wd.embed_count * wd.ablk_size; 1101da177e4SLinus Torvalds brelse(bh); 1111da177e4SLinus Torvalds bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr); 1121da177e4SLinus Torvalds if (!bh) 1131da177e4SLinus Torvalds return -EIO; 1141da177e4SLinus Torvalds } 1151da177e4SLinus Torvalds if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIG)) 1161da177e4SLinus Torvalds break; 1171da177e4SLinus Torvalds brelse(bh); 1181da177e4SLinus Torvalds 1191da177e4SLinus Torvalds /* check for a partition block 1201da177e4SLinus Torvalds * (should do this only for cdrom/loop though) 1211da177e4SLinus Torvalds */ 1221da177e4SLinus Torvalds if (hfs_part_find(sb, &part_start, &part_size)) 1231da177e4SLinus Torvalds return -EINVAL; 1241da177e4SLinus Torvalds } 1251da177e4SLinus Torvalds 1261da177e4SLinus Torvalds blocksize = be32_to_cpu(vhdr->blocksize); 1271da177e4SLinus Torvalds brelse(bh); 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvalds /* block size must be at least as large as a sector 1301da177e4SLinus Torvalds * and a multiple of 2 1311da177e4SLinus Torvalds */ 1321da177e4SLinus Torvalds if (blocksize < HFSPLUS_SECTOR_SIZE || 1331da177e4SLinus Torvalds ((blocksize - 1) & blocksize)) 1341da177e4SLinus Torvalds return -EINVAL; 1351da177e4SLinus Torvalds HFSPLUS_SB(sb).alloc_blksz = blocksize; 1361da177e4SLinus Torvalds HFSPLUS_SB(sb).alloc_blksz_shift = 0; 1371da177e4SLinus Torvalds while ((blocksize >>= 1) != 0) 1381da177e4SLinus Torvalds HFSPLUS_SB(sb).alloc_blksz_shift++; 1391da177e4SLinus Torvalds blocksize = min(HFSPLUS_SB(sb).alloc_blksz, (u32)PAGE_SIZE); 1401da177e4SLinus Torvalds 1411da177e4SLinus Torvalds /* align block size to block offset */ 1421da177e4SLinus Torvalds while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1)) 1431da177e4SLinus Torvalds blocksize >>= 1; 1441da177e4SLinus Torvalds 1451da177e4SLinus Torvalds if (sb_set_blocksize(sb, blocksize) != blocksize) { 146634725a9SRoman Zippel printk(KERN_ERR "hfs: unable to set blocksize to %u!\n", blocksize); 1471da177e4SLinus Torvalds return -EINVAL; 1481da177e4SLinus Torvalds } 1491da177e4SLinus Torvalds 1501da177e4SLinus Torvalds HFSPLUS_SB(sb).blockoffset = part_start >> 1511da177e4SLinus Torvalds (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT); 1521da177e4SLinus Torvalds HFSPLUS_SB(sb).sect_count = part_size; 1531da177e4SLinus Torvalds HFSPLUS_SB(sb).fs_shift = HFSPLUS_SB(sb).alloc_blksz_shift - 1541da177e4SLinus Torvalds sb->s_blocksize_bits; 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr); 1571da177e4SLinus Torvalds if (!bh) 1581da177e4SLinus Torvalds return -EIO; 1591da177e4SLinus Torvalds 1601da177e4SLinus Torvalds /* should still be the same... */ 1611da177e4SLinus Torvalds if (be16_to_cpu(vhdr->signature) != HFSPLUS_VOLHEAD_SIG) 1621da177e4SLinus Torvalds goto error; 1631da177e4SLinus Torvalds HFSPLUS_SB(sb).s_vhbh = bh; 1641da177e4SLinus Torvalds HFSPLUS_SB(sb).s_vhdr = vhdr; 1651da177e4SLinus Torvalds 1661da177e4SLinus Torvalds return 0; 1671da177e4SLinus Torvalds error: 1681da177e4SLinus Torvalds brelse(bh); 1691da177e4SLinus Torvalds return -EINVAL; 1701da177e4SLinus Torvalds } 171