forked from luck/tmp_suning_uos_patched
hfsplus: use raw bio access for partition tables
Switch the hfsplus partition table reding for cdroms to use our bio helpers. Again we don't rely on any caching in the buffer_heads, and this gets rid of the last buffer_head use in hfsplus. Signed-off-by: Christoph Hellwig <hch@tuxera.com>
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52399b171d
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358f26d526
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@ -401,23 +401,6 @@ static inline struct hfsplus_inode_info *HFSPLUS_I(struct inode *inode)
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return list_entry(inode, struct hfsplus_inode_info, vfs_inode);
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}
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#define sb_bread512(sb, sec, data) ({ \
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struct buffer_head *__bh; \
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sector_t __block; \
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loff_t __start; \
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int __offset; \
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\
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__start = (loff_t)(sec) << HFSPLUS_SECTOR_SHIFT;\
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__block = __start >> (sb)->s_blocksize_bits; \
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__offset = __start & ((sb)->s_blocksize - 1); \
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__bh = sb_bread((sb), __block); \
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if (likely(__bh != NULL)) \
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data = (void *)(__bh->b_data + __offset);\
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else \
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data = NULL; \
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__bh; \
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})
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/* time macros */
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#define __hfsp_mt2ut(t) (be32_to_cpu(t) - 2082844800U)
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#define __hfsp_ut2mt(t) (cpu_to_be32(t + 2082844800U))
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@ -13,6 +13,7 @@
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*
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*/
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#include <linux/slab.h>
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#include "hfsplus_fs.h"
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/* offsets to various blocks */
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@ -65,70 +66,87 @@ struct old_pmap {
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} pdEntry[42];
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} __packed;
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/*
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* hfs_part_find()
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*
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* Parse the partition map looking for the
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* start and length of the 'part'th HFS partition.
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*/
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int hfs_part_find(struct super_block *sb,
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sector_t *part_start, sector_t *part_size)
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static int hfs_parse_old_pmap(struct super_block *sb, struct old_pmap *pm,
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sector_t *part_start, sector_t *part_size)
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{
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struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
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struct buffer_head *bh;
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__be16 *data;
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int i, size, res;
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int i;
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res = -ENOENT;
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bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);
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if (!bh)
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return -EIO;
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for (i = 0; i < 42; i++) {
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struct old_pmap_entry *p = &pm->pdEntry[i];
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switch (be16_to_cpu(*data)) {
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case HFS_OLD_PMAP_MAGIC:
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{
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struct old_pmap *pm;
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struct old_pmap_entry *p;
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pm = (struct old_pmap *)bh->b_data;
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p = pm->pdEntry;
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size = 42;
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for (i = 0; i < size; p++, i++) {
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if (p->pdStart && p->pdSize &&
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p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
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(sbi->part < 0 || sbi->part == i)) {
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*part_start += be32_to_cpu(p->pdStart);
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*part_size = be32_to_cpu(p->pdSize);
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res = 0;
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}
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if (p->pdStart && p->pdSize &&
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p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&
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(sbi->part < 0 || sbi->part == i)) {
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*part_start += be32_to_cpu(p->pdStart);
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*part_size = be32_to_cpu(p->pdSize);
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return 0;
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}
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break;
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}
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case HFS_NEW_PMAP_MAGIC:
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{
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struct new_pmap *pm;
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pm = (struct new_pmap *)bh->b_data;
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size = be32_to_cpu(pm->pmMapBlkCnt);
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for (i = 0; i < size;) {
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if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
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(sbi->part < 0 || sbi->part == i)) {
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*part_start += be32_to_cpu(pm->pmPyPartStart);
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*part_size = be32_to_cpu(pm->pmPartBlkCnt);
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res = 0;
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break;
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}
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brelse(bh);
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bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);
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if (!bh)
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return -EIO;
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if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))
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break;
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}
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break;
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}
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}
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brelse(bh);
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return -ENOENT;
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}
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static int hfs_parse_new_pmap(struct super_block *sb, struct new_pmap *pm,
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sector_t *part_start, sector_t *part_size)
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{
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struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
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int size = be32_to_cpu(pm->pmMapBlkCnt);
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int res;
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int i = 0;
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do {
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if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&
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(sbi->part < 0 || sbi->part == i)) {
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*part_start += be32_to_cpu(pm->pmPyPartStart);
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*part_size = be32_to_cpu(pm->pmPartBlkCnt);
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return 0;
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}
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if (++i >= size)
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return -ENOENT;
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res = hfsplus_submit_bio(sb->s_bdev,
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*part_start + HFS_PMAP_BLK + i,
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pm, READ);
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if (res)
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return res;
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} while (pm->pmSig == cpu_to_be16(HFS_NEW_PMAP_MAGIC));
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return -ENOENT;
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}
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/*
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* Parse the partition map looking for the start and length of a
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* HFS/HFS+ partition.
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*/
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int hfs_part_find(struct super_block *sb,
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sector_t *part_start, sector_t *part_size)
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{
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void *data;
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int res;
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data = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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res = hfsplus_submit_bio(sb->s_bdev, *part_start + HFS_PMAP_BLK,
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data, READ);
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if (res)
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return res;
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switch (be16_to_cpu(*((__be16 *)data))) {
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case HFS_OLD_PMAP_MAGIC:
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res = hfs_parse_old_pmap(sb, data, part_start, part_size);
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break;
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case HFS_NEW_PMAP_MAGIC:
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res = hfs_parse_new_pmap(sb, data, part_start, part_size);
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break;
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default:
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res = -ENOENT;
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break;
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}
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kfree(data);
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return res;
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}
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