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1da177e4 LT |
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> | |
1da177e4 LT |
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 | ||
915ab236 FF |
27 | /** |
28 | * hfsplus_submit_bio - Perform block I/O | |
6596528e SF |
29 | * @sb: super block of volume for I/O |
30 | * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes | |
31 | * @buf: buffer for I/O | |
32 | * @data: output pointer for location of requested data | |
67ed2596 MC |
33 | * @op: direction of I/O |
34 | * @op_flags: request op flags | |
6596528e SF |
35 | * |
36 | * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than | |
37 | * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads | |
38 | * @data will return a pointer to the start of the requested sector, | |
39 | * which may not be the same location as @buf. | |
40 | * | |
41 | * If @sector is not aligned to the bdev logical block size it will | |
42 | * be rounded down. For writes this means that @buf should contain data | |
43 | * that starts at the rounded-down address. As long as the data was | |
44 | * read using hfsplus_submit_bio() and the same buffer is used things | |
45 | * will work correctly. | |
46 | */ | |
47 | int hfsplus_submit_bio(struct super_block *sb, sector_t sector, | |
67ed2596 | 48 | void *buf, void **data, int op, int op_flags) |
52399b17 | 49 | { |
52399b17 | 50 | struct bio *bio; |
50176dde | 51 | int ret = 0; |
a6dc8c04 | 52 | u64 io_size; |
6596528e SF |
53 | loff_t start; |
54 | int offset; | |
55 | ||
56 | /* | |
57 | * Align sector to hardware sector size and find offset. We | |
58 | * assume that io_size is a power of two, which _should_ | |
59 | * be true. | |
60 | */ | |
61 | io_size = hfsplus_min_io_size(sb); | |
62 | start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT; | |
63 | offset = start & (io_size - 1); | |
64 | sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1); | |
52399b17 CH |
65 | |
66 | bio = bio_alloc(GFP_NOIO, 1); | |
4f024f37 | 67 | bio->bi_iter.bi_sector = sector; |
6596528e | 68 | bio->bi_bdev = sb->s_bdev; |
67ed2596 | 69 | bio_set_op_attrs(bio, op, op_flags); |
52399b17 | 70 | |
67ed2596 | 71 | if (op != WRITE && data) |
6596528e SF |
72 | *data = (u8 *)buf + offset; |
73 | ||
74 | while (io_size > 0) { | |
75 | unsigned int page_offset = offset_in_page(buf); | |
76 | unsigned int len = min_t(unsigned int, PAGE_SIZE - page_offset, | |
77 | io_size); | |
78 | ||
79 | ret = bio_add_page(bio, virt_to_page(buf), len, page_offset); | |
80 | if (ret != len) { | |
81 | ret = -EIO; | |
82 | goto out; | |
83 | } | |
84 | io_size -= len; | |
85 | buf = (u8 *)buf + len; | |
86 | } | |
52399b17 | 87 | |
4e49ea4a | 88 | ret = submit_bio_wait(bio); |
6596528e | 89 | out: |
50176dde | 90 | bio_put(bio); |
6596528e | 91 | return ret < 0 ? ret : 0; |
52399b17 CH |
92 | } |
93 | ||
1da177e4 LT |
94 | static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd) |
95 | { | |
96 | u32 extent; | |
97 | u16 attrib; | |
2179d372 | 98 | __be16 sig; |
1da177e4 | 99 | |
2179d372 DE |
100 | sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG); |
101 | if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) && | |
102 | sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) | |
1da177e4 LT |
103 | return 0; |
104 | ||
105 | attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB)); | |
106 | if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) || | |
107 | !(attrib & HFSP_WRAP_ATTRIB_SPARED)) | |
108 | return 0; | |
109 | ||
2753cc28 AS |
110 | wd->ablk_size = |
111 | be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE)); | |
1da177e4 LT |
112 | if (wd->ablk_size < HFSPLUS_SECTOR_SIZE) |
113 | return 0; | |
114 | if (wd->ablk_size % HFSPLUS_SECTOR_SIZE) | |
115 | return 0; | |
2753cc28 AS |
116 | wd->ablk_start = |
117 | be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART)); | |
1da177e4 | 118 | |
8b3789e5 | 119 | extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT); |
1da177e4 LT |
120 | wd->embed_start = (extent >> 16) & 0xFFFF; |
121 | wd->embed_count = extent & 0xFFFF; | |
122 | ||
123 | return 1; | |
124 | } | |
125 | ||
126 | static int hfsplus_get_last_session(struct super_block *sb, | |
127 | sector_t *start, sector_t *size) | |
128 | { | |
129 | struct cdrom_multisession ms_info; | |
130 | struct cdrom_tocentry te; | |
131 | int res; | |
132 | ||
133 | /* default values */ | |
134 | *start = 0; | |
135 | *size = sb->s_bdev->bd_inode->i_size >> 9; | |
136 | ||
dd73a01a CH |
137 | if (HFSPLUS_SB(sb)->session >= 0) { |
138 | te.cdte_track = HFSPLUS_SB(sb)->session; | |
1da177e4 | 139 | te.cdte_format = CDROM_LBA; |
2753cc28 AS |
140 | res = ioctl_by_bdev(sb->s_bdev, |
141 | CDROMREADTOCENTRY, (unsigned long)&te); | |
1da177e4 LT |
142 | if (!res && (te.cdte_ctrl & CDROM_DATA_TRACK) == 4) { |
143 | *start = (sector_t)te.cdte_addr.lba << 2; | |
144 | return 0; | |
145 | } | |
d6142673 | 146 | pr_err("invalid session number or type of track\n"); |
1da177e4 LT |
147 | return -EINVAL; |
148 | } | |
149 | ms_info.addr_format = CDROM_LBA; | |
2753cc28 AS |
150 | res = ioctl_by_bdev(sb->s_bdev, CDROMMULTISESSION, |
151 | (unsigned long)&ms_info); | |
1da177e4 LT |
152 | if (!res && ms_info.xa_flag) |
153 | *start = (sector_t)ms_info.addr.lba << 2; | |
154 | return 0; | |
155 | } | |
156 | ||
157 | /* Find the volume header and fill in some minimum bits in superblock */ | |
158 | /* Takes in super block, returns true if good data read */ | |
159 | int hfsplus_read_wrapper(struct super_block *sb) | |
160 | { | |
dd73a01a | 161 | struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); |
1da177e4 LT |
162 | struct hfsplus_wd wd; |
163 | sector_t part_start, part_size; | |
164 | u32 blocksize; | |
52399b17 | 165 | int error = 0; |
1da177e4 | 166 | |
52399b17 | 167 | error = -EINVAL; |
1da177e4 LT |
168 | blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE); |
169 | if (!blocksize) | |
52399b17 | 170 | goto out; |
1da177e4 LT |
171 | |
172 | if (hfsplus_get_last_session(sb, &part_start, &part_size)) | |
52399b17 | 173 | goto out; |
1da177e4 | 174 | |
52399b17 | 175 | error = -ENOMEM; |
6596528e SF |
176 | sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); |
177 | if (!sbi->s_vhdr_buf) | |
52399b17 | 178 | goto out; |
6596528e SF |
179 | sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); |
180 | if (!sbi->s_backup_vhdr_buf) | |
52399b17 CH |
181 | goto out_free_vhdr; |
182 | ||
183 | reread: | |
6596528e SF |
184 | error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, |
185 | sbi->s_vhdr_buf, (void **)&sbi->s_vhdr, | |
67ed2596 | 186 | REQ_OP_READ, 0); |
52399b17 CH |
187 | if (error) |
188 | goto out_free_backup_vhdr; | |
189 | ||
190 | error = -EINVAL; | |
191 | switch (sbi->s_vhdr->signature) { | |
192 | case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX): | |
193 | set_bit(HFSPLUS_SB_HFSX, &sbi->flags); | |
194 | /*FALLTHRU*/ | |
195 | case cpu_to_be16(HFSPLUS_VOLHEAD_SIG): | |
196 | break; | |
197 | case cpu_to_be16(HFSP_WRAP_MAGIC): | |
198 | if (!hfsplus_read_mdb(sbi->s_vhdr, &wd)) | |
a1dbcef0 | 199 | goto out_free_backup_vhdr; |
52399b17 | 200 | wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT; |
4ba2d5fd CH |
201 | part_start += (sector_t)wd.ablk_start + |
202 | (sector_t)wd.embed_start * wd.ablk_size; | |
203 | part_size = (sector_t)wd.embed_count * wd.ablk_size; | |
52399b17 CH |
204 | goto reread; |
205 | default: | |
206 | /* | |
207 | * Check for a partition block. | |
208 | * | |
1da177e4 LT |
209 | * (should do this only for cdrom/loop though) |
210 | */ | |
211 | if (hfs_part_find(sb, &part_start, &part_size)) | |
a1dbcef0 | 212 | goto out_free_backup_vhdr; |
52399b17 CH |
213 | goto reread; |
214 | } | |
215 | ||
6596528e SF |
216 | error = hfsplus_submit_bio(sb, part_start + part_size - 2, |
217 | sbi->s_backup_vhdr_buf, | |
67ed2596 MC |
218 | (void **)&sbi->s_backup_vhdr, REQ_OP_READ, |
219 | 0); | |
52399b17 CH |
220 | if (error) |
221 | goto out_free_backup_vhdr; | |
222 | ||
223 | error = -EINVAL; | |
224 | if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) { | |
d6142673 | 225 | pr_warn("invalid secondary volume header\n"); |
52399b17 | 226 | goto out_free_backup_vhdr; |
1da177e4 LT |
227 | } |
228 | ||
52399b17 | 229 | blocksize = be32_to_cpu(sbi->s_vhdr->blocksize); |
1da177e4 | 230 | |
52399b17 CH |
231 | /* |
232 | * Block size must be at least as large as a sector and a multiple of 2. | |
1da177e4 | 233 | */ |
52399b17 CH |
234 | if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize)) |
235 | goto out_free_backup_vhdr; | |
dd73a01a | 236 | sbi->alloc_blksz = blocksize; |
297cc272 | 237 | sbi->alloc_blksz_shift = ilog2(blocksize); |
915ab236 | 238 | blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE); |
1da177e4 | 239 | |
52399b17 CH |
240 | /* |
241 | * Align block size to block offset. | |
242 | */ | |
1da177e4 LT |
243 | while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1)) |
244 | blocksize >>= 1; | |
245 | ||
246 | if (sb_set_blocksize(sb, blocksize) != blocksize) { | |
d6142673 | 247 | pr_err("unable to set blocksize to %u!\n", blocksize); |
52399b17 | 248 | goto out_free_backup_vhdr; |
1da177e4 LT |
249 | } |
250 | ||
dd73a01a CH |
251 | sbi->blockoffset = |
252 | part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT); | |
52399b17 | 253 | sbi->part_start = part_start; |
dd73a01a CH |
254 | sbi->sect_count = part_size; |
255 | sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits; | |
1da177e4 | 256 | return 0; |
52399b17 CH |
257 | |
258 | out_free_backup_vhdr: | |
f588c960 | 259 | kfree(sbi->s_backup_vhdr_buf); |
52399b17 | 260 | out_free_vhdr: |
f588c960 | 261 | kfree(sbi->s_vhdr_buf); |
52399b17 CH |
262 | out: |
263 | return error; | |
1da177e4 | 264 | } |