1 /* 2 * linux/fs/hfsplus/wrapper.c 3 * 4 * Copyright (C) 2001 5 * Brad Boyer (flar@allandria.com) 6 * (C) 2003 Ardis Technologies <roman@ardistech.com> 7 * 8 * Handling of HFS wrappers around HFS+ volumes 9 */ 10 11 #include <linux/fs.h> 12 #include <linux/blkdev.h> 13 #include <linux/cdrom.h> 14 #include <linux/genhd.h> 15 #include <asm/unaligned.h> 16 17 #include "hfsplus_fs.h" 18 #include "hfsplus_raw.h" 19 20 struct hfsplus_wd { 21 u32 ablk_size; 22 u16 ablk_start; 23 u16 embed_start; 24 u16 embed_count; 25 }; 26 27 static void hfsplus_end_io_sync(struct bio *bio, int err) 28 { 29 if (err) 30 clear_bit(BIO_UPTODATE, &bio->bi_flags); 31 complete(bio->bi_private); 32 } 33 34 int hfsplus_submit_bio(struct block_device *bdev, sector_t sector, 35 void *data, int rw) 36 { 37 DECLARE_COMPLETION_ONSTACK(wait); 38 struct bio *bio; 39 int ret = 0; 40 41 bio = bio_alloc(GFP_NOIO, 1); 42 bio->bi_sector = sector; 43 bio->bi_bdev = bdev; 44 bio->bi_end_io = hfsplus_end_io_sync; 45 bio->bi_private = &wait; 46 47 /* 48 * We always submit one sector at a time, so bio_add_page must not fail. 49 */ 50 if (bio_add_page(bio, virt_to_page(data), HFSPLUS_SECTOR_SIZE, 51 offset_in_page(data)) != HFSPLUS_SECTOR_SIZE) 52 BUG(); 53 54 submit_bio(rw, bio); 55 wait_for_completion(&wait); 56 57 if (!bio_flagged(bio, BIO_UPTODATE)) 58 ret = -EIO; 59 60 bio_put(bio); 61 return ret; 62 } 63 64 static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd) 65 { 66 u32 extent; 67 u16 attrib; 68 __be16 sig; 69 70 sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG); 71 if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) && 72 sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) 73 return 0; 74 75 attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB)); 76 if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) || 77 !(attrib & HFSP_WRAP_ATTRIB_SPARED)) 78 return 0; 79 80 wd->ablk_size = 81 be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE)); 82 if (wd->ablk_size < HFSPLUS_SECTOR_SIZE) 83 return 0; 84 if (wd->ablk_size % HFSPLUS_SECTOR_SIZE) 85 return 0; 86 wd->ablk_start = 87 be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART)); 88 89 extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT); 90 wd->embed_start = (extent >> 16) & 0xFFFF; 91 wd->embed_count = extent & 0xFFFF; 92 93 return 1; 94 } 95 96 static int hfsplus_get_last_session(struct super_block *sb, 97 sector_t *start, sector_t *size) 98 { 99 struct cdrom_multisession ms_info; 100 struct cdrom_tocentry te; 101 int res; 102 103 /* default values */ 104 *start = 0; 105 *size = sb->s_bdev->bd_inode->i_size >> 9; 106 107 if (HFSPLUS_SB(sb)->session >= 0) { 108 te.cdte_track = HFSPLUS_SB(sb)->session; 109 te.cdte_format = CDROM_LBA; 110 res = ioctl_by_bdev(sb->s_bdev, 111 CDROMREADTOCENTRY, (unsigned long)&te); 112 if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) { 113 *start = (sector_t)te.cdte_addr.lba << 2; 114 return 0; 115 } 116 printk(KERN_ERR "hfs: invalid session number or type of track\n"); 117 return -EINVAL; 118 } 119 ms_info.addr_format = CDROM_LBA; 120 res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, 121 (unsigned long)&ms_info); 122 if (!res && ms_info.xa_flag) 123 *start = (sector_t)ms_info.addr.lba << 2; 124 return 0; 125 } 126 127 /* Find the volume header and fill in some minimum bits in superblock */ 128 /* Takes in super block, returns true if good data read */ 129 int hfsplus_read_wrapper(struct super_block *sb) 130 { 131 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); 132 struct hfsplus_wd wd; 133 sector_t part_start, part_size; 134 u32 blocksize; 135 int error = 0; 136 137 error = -EINVAL; 138 blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE); 139 if (!blocksize) 140 goto out; 141 142 if (hfsplus_get_last_session(sb, &part_start, &part_size)) 143 goto out; 144 if ((u64)part_start + part_size > 0x100000000ULL) { 145 pr_err("hfs: volumes larger than 2TB are not supported yet\n"); 146 goto out; 147 } 148 149 error = -ENOMEM; 150 sbi->s_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL); 151 if (!sbi->s_vhdr) 152 goto out; 153 sbi->s_backup_vhdr = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL); 154 if (!sbi->s_backup_vhdr) 155 goto out_free_vhdr; 156 157 reread: 158 error = hfsplus_submit_bio(sb->s_bdev, 159 part_start + HFSPLUS_VOLHEAD_SECTOR, 160 sbi->s_vhdr, READ); 161 if (error) 162 goto out_free_backup_vhdr; 163 164 error = -EINVAL; 165 switch (sbi->s_vhdr->signature) { 166 case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX): 167 set_bit(HFSPLUS_SB_HFSX, &sbi->flags); 168 /*FALLTHRU*/ 169 case cpu_to_be16(HFSPLUS_VOLHEAD_SIG): 170 break; 171 case cpu_to_be16(HFSP_WRAP_MAGIC): 172 if (!hfsplus_read_mdb(sbi->s_vhdr, &wd)) 173 goto out_free_backup_vhdr; 174 wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT; 175 part_start += wd.ablk_start + wd.embed_start * wd.ablk_size; 176 part_size = wd.embed_count * wd.ablk_size; 177 goto reread; 178 default: 179 /* 180 * Check for a partition block. 181 * 182 * (should do this only for cdrom/loop though) 183 */ 184 if (hfs_part_find(sb, &part_start, &part_size)) 185 goto out_free_backup_vhdr; 186 goto reread; 187 } 188 189 error = hfsplus_submit_bio(sb->s_bdev, 190 part_start + part_size - 2, 191 sbi->s_backup_vhdr, READ); 192 if (error) 193 goto out_free_backup_vhdr; 194 195 error = -EINVAL; 196 if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) { 197 printk(KERN_WARNING 198 "hfs: invalid secondary volume header\n"); 199 goto out_free_backup_vhdr; 200 } 201 202 blocksize = be32_to_cpu(sbi->s_vhdr->blocksize); 203 204 /* 205 * Block size must be at least as large as a sector and a multiple of 2. 206 */ 207 if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize)) 208 goto out_free_backup_vhdr; 209 sbi->alloc_blksz = blocksize; 210 sbi->alloc_blksz_shift = 0; 211 while ((blocksize >>= 1) != 0) 212 sbi->alloc_blksz_shift++; 213 blocksize = min(sbi->alloc_blksz, (u32)PAGE_SIZE); 214 215 /* 216 * Align block size to block offset. 217 */ 218 while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1)) 219 blocksize >>= 1; 220 221 if (sb_set_blocksize(sb, blocksize) != blocksize) { 222 printk(KERN_ERR "hfs: unable to set blocksize to %u!\n", 223 blocksize); 224 goto out_free_backup_vhdr; 225 } 226 227 sbi->blockoffset = 228 part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT); 229 sbi->part_start = part_start; 230 sbi->sect_count = part_size; 231 sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits; 232 return 0; 233 234 out_free_backup_vhdr: 235 kfree(sbi->s_backup_vhdr); 236 out_free_vhdr: 237 kfree(sbi->s_vhdr); 238 out: 239 return error; 240 } 241