blob: bed78ac8f6d1f5e530a93c0afac22e1cfdf2178a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/unaligned.h>
16
17#include "hfsplus_fs.h"
18#include "hfsplus_raw.h"
19
20struct hfsplus_wd {
21 u32 ablk_size;
22 u16 ablk_start;
23 u16 embed_start;
24 u16 embed_count;
25};
26
27static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
28{
29 u32 extent;
30 u16 attrib;
David Elliott2179d372006-01-18 17:43:08 -080031 __be16 sig;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
David Elliott2179d372006-01-18 17:43:08 -080033 sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG);
34 if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
35 sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 return 0;
37
38 attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB));
39 if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) ||
40 !(attrib & HFSP_WRAP_ATTRIB_SPARED))
41 return 0;
42
43 wd->ablk_size = be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
44 if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
45 return 0;
46 if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
47 return 0;
48 wd->ablk_start = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
49
Harvey Harrison8b3789e2008-04-29 01:03:44 -070050 extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 wd->embed_start = (extent >> 16) & 0xFFFF;
52 wd->embed_count = extent & 0xFFFF;
53
54 return 1;
55}
56
57static int hfsplus_get_last_session(struct super_block *sb,
58 sector_t *start, sector_t *size)
59{
60 struct cdrom_multisession ms_info;
61 struct cdrom_tocentry te;
62 int res;
63
64 /* default values */
65 *start = 0;
66 *size = sb->s_bdev->bd_inode->i_size >> 9;
67
68 if (HFSPLUS_SB(sb).session >= 0) {
69 te.cdte_track = HFSPLUS_SB(sb).session;
70 te.cdte_format = CDROM_LBA;
71 res = ioctl_by_bdev(sb->s_bdev, CDROMREADTOCENTRY, (unsigned long)&te);
72 if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) {
73 *start = (sector_t)te.cdte_addr.lba << 2;
74 return 0;
75 }
Roman Zippel634725a2006-01-18 17:43:05 -080076 printk(KERN_ERR "hfs: invalid session number or type of track\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 return -EINVAL;
78 }
79 ms_info.addr_format = CDROM_LBA;
80 res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
81 if (!res && ms_info.xa_flag)
82 *start = (sector_t)ms_info.addr.lba << 2;
83 return 0;
84}
85
86/* Find the volume header and fill in some minimum bits in superblock */
87/* Takes in super block, returns true if good data read */
88int hfsplus_read_wrapper(struct super_block *sb)
89{
90 struct buffer_head *bh;
91 struct hfsplus_vh *vhdr;
92 struct hfsplus_wd wd;
93 sector_t part_start, part_size;
94 u32 blocksize;
95
96 blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
97 if (!blocksize)
98 return -EINVAL;
99
100 if (hfsplus_get_last_session(sb, &part_start, &part_size))
101 return -EINVAL;
Ben Hutchings5c36fe32009-10-26 16:49:51 -0700102 if ((u64)part_start + part_size > 0x100000000ULL) {
103 pr_err("hfs: volumes larger than 2TB are not supported yet\n");
104 return -EINVAL;
105 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 while (1) {
107 bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
108 if (!bh)
109 return -EIO;
110
111 if (vhdr->signature == cpu_to_be16(HFSP_WRAP_MAGIC)) {
112 if (!hfsplus_read_mdb(vhdr, &wd))
113 goto error;
114 wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
115 part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
116 part_size = wd.embed_count * wd.ablk_size;
117 brelse(bh);
118 bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
119 if (!bh)
120 return -EIO;
121 }
122 if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIG))
123 break;
David Elliott2179d372006-01-18 17:43:08 -0800124 if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) {
125 HFSPLUS_SB(sb).flags |= HFSPLUS_SB_HFSX;
126 break;
127 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 brelse(bh);
129
130 /* check for a partition block
131 * (should do this only for cdrom/loop though)
132 */
133 if (hfs_part_find(sb, &part_start, &part_size))
134 return -EINVAL;
135 }
136
137 blocksize = be32_to_cpu(vhdr->blocksize);
138 brelse(bh);
139
140 /* block size must be at least as large as a sector
141 * and a multiple of 2
142 */
143 if (blocksize < HFSPLUS_SECTOR_SIZE ||
144 ((blocksize - 1) & blocksize))
145 return -EINVAL;
146 HFSPLUS_SB(sb).alloc_blksz = blocksize;
147 HFSPLUS_SB(sb).alloc_blksz_shift = 0;
148 while ((blocksize >>= 1) != 0)
149 HFSPLUS_SB(sb).alloc_blksz_shift++;
150 blocksize = min(HFSPLUS_SB(sb).alloc_blksz, (u32)PAGE_SIZE);
151
152 /* align block size to block offset */
153 while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
154 blocksize >>= 1;
155
156 if (sb_set_blocksize(sb, blocksize) != blocksize) {
Roman Zippel634725a2006-01-18 17:43:05 -0800157 printk(KERN_ERR "hfs: unable to set blocksize to %u!\n", blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 return -EINVAL;
159 }
160
161 HFSPLUS_SB(sb).blockoffset = part_start >>
162 (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
163 HFSPLUS_SB(sb).sect_count = part_size;
164 HFSPLUS_SB(sb).fs_shift = HFSPLUS_SB(sb).alloc_blksz_shift -
165 sb->s_blocksize_bits;
166
167 bh = sb_bread512(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, vhdr);
168 if (!bh)
169 return -EIO;
170
171 /* should still be the same... */
David Elliott2179d372006-01-18 17:43:08 -0800172 if (vhdr->signature != (HFSPLUS_SB(sb).flags & HFSPLUS_SB_HFSX ?
173 cpu_to_be16(HFSPLUS_VOLHEAD_SIGX) :
174 cpu_to_be16(HFSPLUS_VOLHEAD_SIG)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 goto error;
176 HFSPLUS_SB(sb).s_vhbh = bh;
177 HFSPLUS_SB(sb).s_vhdr = vhdr;
178
179 return 0;
180 error:
181 brelse(bh);
182 return -EINVAL;
183}