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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/hfsplus/wrapper.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handling of HFS wrappers around HFS+ volumes
10 */
11
12#include <linux/fs.h>
13#include <linux/blkdev.h>
14#include <linux/cdrom.h>
15#include <linux/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
27/**
28 * hfsplus_submit_bio - Perform block I/O
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
33 * @opf: I/O operation type and flags
34 *
35 * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than
36 * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads
37 * @data will return a pointer to the start of the requested sector,
38 * which may not be the same location as @buf.
39 *
40 * If @sector is not aligned to the bdev logical block size it will
41 * be rounded down. For writes this means that @buf should contain data
42 * that starts at the rounded-down address. As long as the data was
43 * read using hfsplus_submit_bio() and the same buffer is used things
44 * will work correctly.
45 *
46 * Returns: %0 on success else -errno code
47 */
48int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
49 void *buf, void **data, blk_opf_t opf)
50{
51 const enum req_op op = opf & REQ_OP_MASK;
52 struct bio *bio;
53 int ret = 0;
54 u64 io_size;
55 loff_t start;
56 int offset;
57
58 /*
59 * Align sector to hardware sector size and find offset. We
60 * assume that io_size is a power of two, which _should_
61 * be true.
62 */
63 io_size = hfsplus_min_io_size(sb);
64 start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT;
65 offset = start & (io_size - 1);
66 sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1);
67
68 bio = bio_alloc(sb->s_bdev, 1, opf, GFP_NOIO);
69 bio->bi_iter.bi_sector = sector;
70
71 if (op != REQ_OP_WRITE && data)
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 }
87
88 ret = submit_bio_wait(bio);
89out:
90 bio_put(bio);
91 return ret < 0 ? ret : 0;
92}
93
94static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
95{
96 u32 extent;
97 u16 attrib;
98 __be16 sig;
99
100 sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG);
101 if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
102 sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
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
110 wd->ablk_size =
111 be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
112 if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
113 return 0;
114 if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
115 return 0;
116 wd->ablk_start =
117 be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
118
119 extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
120 wd->embed_start = (extent >> 16) & 0xFFFF;
121 wd->embed_count = extent & 0xFFFF;
122
123 return 1;
124}
125
126static int hfsplus_get_last_session(struct super_block *sb,
127 sector_t *start, sector_t *size)
128{
129 struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
130
131 /* default values */
132 *start = 0;
133 *size = bdev_nr_sectors(sb->s_bdev);
134
135 if (HFSPLUS_SB(sb)->session >= 0) {
136 struct cdrom_tocentry te;
137
138 if (!cdi)
139 return -EINVAL;
140
141 te.cdte_track = HFSPLUS_SB(sb)->session;
142 te.cdte_format = CDROM_LBA;
143 if (cdrom_read_tocentry(cdi, &te) ||
144 (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) {
145 pr_err("invalid session number or type of track\n");
146 return -EINVAL;
147 }
148 *start = (sector_t)te.cdte_addr.lba << 2;
149 } else if (cdi) {
150 struct cdrom_multisession ms_info;
151
152 ms_info.addr_format = CDROM_LBA;
153 if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag)
154 *start = (sector_t)ms_info.addr.lba << 2;
155 }
156
157 return 0;
158}
159
160/* Find the volume header and fill in some minimum bits in superblock */
161/* Takes in super block, returns true if good data read */
162int hfsplus_read_wrapper(struct super_block *sb)
163{
164 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
165 struct hfsplus_wd wd;
166 sector_t part_start, part_size;
167 u32 blocksize;
168 int error = 0;
169
170 error = -EINVAL;
171 blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
172 if (!blocksize)
173 goto out;
174
175 sbi->min_io_size = blocksize;
176
177 if (hfsplus_get_last_session(sb, &part_start, &part_size))
178 goto out;
179
180 error = -ENOMEM;
181 sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
182 if (!sbi->s_vhdr_buf)
183 goto out;
184 sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
185 if (!sbi->s_backup_vhdr_buf)
186 goto out_free_vhdr;
187
188reread:
189 error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR,
190 sbi->s_vhdr_buf, (void **)&sbi->s_vhdr,
191 REQ_OP_READ);
192 if (error)
193 goto out_free_backup_vhdr;
194
195 error = -EINVAL;
196 switch (sbi->s_vhdr->signature) {
197 case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
198 set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
199 fallthrough;
200 case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
201 break;
202 case cpu_to_be16(HFSP_WRAP_MAGIC):
203 if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
204 goto out_free_backup_vhdr;
205 wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
206 part_start += (sector_t)wd.ablk_start +
207 (sector_t)wd.embed_start * wd.ablk_size;
208 part_size = (sector_t)wd.embed_count * wd.ablk_size;
209 goto reread;
210 default:
211 /*
212 * Check for a partition block.
213 *
214 * (should do this only for cdrom/loop though)
215 */
216 if (hfs_part_find(sb, &part_start, &part_size))
217 goto out_free_backup_vhdr;
218 goto reread;
219 }
220
221 error = hfsplus_submit_bio(sb, part_start + part_size - 2,
222 sbi->s_backup_vhdr_buf,
223 (void **)&sbi->s_backup_vhdr, REQ_OP_READ);
224 if (error)
225 goto out_free_backup_vhdr;
226
227 error = -EINVAL;
228 if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
229 pr_warn("invalid secondary volume header\n");
230 goto out_free_backup_vhdr;
231 }
232
233 blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
234
235 /*
236 * Block size must be at least as large as a sector and a multiple of 2.
237 */
238 if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
239 goto out_free_backup_vhdr;
240 sbi->alloc_blksz = blocksize;
241 sbi->alloc_blksz_shift = ilog2(blocksize);
242 blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE);
243
244 /*
245 * Align block size to block offset.
246 */
247 while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
248 blocksize >>= 1;
249
250 if (sb_set_blocksize(sb, blocksize) != blocksize) {
251 pr_err("unable to set blocksize to %u!\n", blocksize);
252 goto out_free_backup_vhdr;
253 }
254
255 sbi->blockoffset =
256 part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
257 sbi->part_start = part_start;
258 sbi->sect_count = part_size;
259 sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
260 return 0;
261
262out_free_backup_vhdr:
263 kfree(sbi->s_backup_vhdr_buf);
264out_free_vhdr:
265 kfree(sbi->s_vhdr_buf);
266out:
267 return error;
268}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/hfsplus/wrapper.c
4 *
5 * Copyright (C) 2001
6 * Brad Boyer (flar@allandria.com)
7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
8 *
9 * Handling of HFS wrappers around HFS+ volumes
10 */
11
12#include <linux/fs.h>
13#include <linux/blkdev.h>
14#include <linux/cdrom.h>
15#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
27/**
28 * hfsplus_submit_bio - Perform block I/O
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
33 * @op: direction of I/O
34 * @op_flags: request op flags
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 */
47int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
48 void *buf, void **data, blk_opf_t opf)
49{
50 const enum req_op op = opf & REQ_OP_MASK;
51 struct bio *bio;
52 int ret = 0;
53 u64 io_size;
54 loff_t start;
55 int offset;
56
57 /*
58 * Align sector to hardware sector size and find offset. We
59 * assume that io_size is a power of two, which _should_
60 * be true.
61 */
62 io_size = hfsplus_min_io_size(sb);
63 start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT;
64 offset = start & (io_size - 1);
65 sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1);
66
67 bio = bio_alloc(sb->s_bdev, 1, opf, GFP_NOIO);
68 bio->bi_iter.bi_sector = sector;
69
70 if (op != REQ_OP_WRITE && data)
71 *data = (u8 *)buf + offset;
72
73 while (io_size > 0) {
74 unsigned int page_offset = offset_in_page(buf);
75 unsigned int len = min_t(unsigned int, PAGE_SIZE - page_offset,
76 io_size);
77
78 ret = bio_add_page(bio, virt_to_page(buf), len, page_offset);
79 if (ret != len) {
80 ret = -EIO;
81 goto out;
82 }
83 io_size -= len;
84 buf = (u8 *)buf + len;
85 }
86
87 ret = submit_bio_wait(bio);
88out:
89 bio_put(bio);
90 return ret < 0 ? ret : 0;
91}
92
93static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
94{
95 u32 extent;
96 u16 attrib;
97 __be16 sig;
98
99 sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG);
100 if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
101 sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
102 return 0;
103
104 attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB));
105 if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) ||
106 !(attrib & HFSP_WRAP_ATTRIB_SPARED))
107 return 0;
108
109 wd->ablk_size =
110 be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
111 if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
112 return 0;
113 if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
114 return 0;
115 wd->ablk_start =
116 be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
117
118 extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
119 wd->embed_start = (extent >> 16) & 0xFFFF;
120 wd->embed_count = extent & 0xFFFF;
121
122 return 1;
123}
124
125static int hfsplus_get_last_session(struct super_block *sb,
126 sector_t *start, sector_t *size)
127{
128 struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
129
130 /* default values */
131 *start = 0;
132 *size = bdev_nr_sectors(sb->s_bdev);
133
134 if (HFSPLUS_SB(sb)->session >= 0) {
135 struct cdrom_tocentry te;
136
137 if (!cdi)
138 return -EINVAL;
139
140 te.cdte_track = HFSPLUS_SB(sb)->session;
141 te.cdte_format = CDROM_LBA;
142 if (cdrom_read_tocentry(cdi, &te) ||
143 (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) {
144 pr_err("invalid session number or type of track\n");
145 return -EINVAL;
146 }
147 *start = (sector_t)te.cdte_addr.lba << 2;
148 } else if (cdi) {
149 struct cdrom_multisession ms_info;
150
151 ms_info.addr_format = CDROM_LBA;
152 if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag)
153 *start = (sector_t)ms_info.addr.lba << 2;
154 }
155
156 return 0;
157}
158
159/* Find the volume header and fill in some minimum bits in superblock */
160/* Takes in super block, returns true if good data read */
161int hfsplus_read_wrapper(struct super_block *sb)
162{
163 struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
164 struct hfsplus_wd wd;
165 sector_t part_start, part_size;
166 u32 blocksize;
167 int error = 0;
168
169 error = -EINVAL;
170 blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
171 if (!blocksize)
172 goto out;
173
174 if (hfsplus_get_last_session(sb, &part_start, &part_size))
175 goto out;
176
177 error = -ENOMEM;
178 sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
179 if (!sbi->s_vhdr_buf)
180 goto out;
181 sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
182 if (!sbi->s_backup_vhdr_buf)
183 goto out_free_vhdr;
184
185reread:
186 error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR,
187 sbi->s_vhdr_buf, (void **)&sbi->s_vhdr,
188 REQ_OP_READ);
189 if (error)
190 goto out_free_backup_vhdr;
191
192 error = -EINVAL;
193 switch (sbi->s_vhdr->signature) {
194 case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
195 set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
196 fallthrough;
197 case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
198 break;
199 case cpu_to_be16(HFSP_WRAP_MAGIC):
200 if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
201 goto out_free_backup_vhdr;
202 wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
203 part_start += (sector_t)wd.ablk_start +
204 (sector_t)wd.embed_start * wd.ablk_size;
205 part_size = (sector_t)wd.embed_count * wd.ablk_size;
206 goto reread;
207 default:
208 /*
209 * Check for a partition block.
210 *
211 * (should do this only for cdrom/loop though)
212 */
213 if (hfs_part_find(sb, &part_start, &part_size))
214 goto out_free_backup_vhdr;
215 goto reread;
216 }
217
218 error = hfsplus_submit_bio(sb, part_start + part_size - 2,
219 sbi->s_backup_vhdr_buf,
220 (void **)&sbi->s_backup_vhdr, REQ_OP_READ);
221 if (error)
222 goto out_free_backup_vhdr;
223
224 error = -EINVAL;
225 if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
226 pr_warn("invalid secondary volume header\n");
227 goto out_free_backup_vhdr;
228 }
229
230 blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
231
232 /*
233 * Block size must be at least as large as a sector and a multiple of 2.
234 */
235 if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
236 goto out_free_backup_vhdr;
237 sbi->alloc_blksz = blocksize;
238 sbi->alloc_blksz_shift = ilog2(blocksize);
239 blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE);
240
241 /*
242 * Align block size to block offset.
243 */
244 while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
245 blocksize >>= 1;
246
247 if (sb_set_blocksize(sb, blocksize) != blocksize) {
248 pr_err("unable to set blocksize to %u!\n", blocksize);
249 goto out_free_backup_vhdr;
250 }
251
252 sbi->blockoffset =
253 part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
254 sbi->part_start = part_start;
255 sbi->sect_count = part_size;
256 sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
257 return 0;
258
259out_free_backup_vhdr:
260 kfree(sbi->s_backup_vhdr_buf);
261out_free_vhdr:
262 kfree(sbi->s_vhdr_buf);
263out:
264 return error;
265}