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Commit 358f26d5 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Christoph Hellwig
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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: default avatarChristoph Hellwig <hch@tuxera.com>
parent 52399b17

fs/hfsplus/hfsplus_fs.h

+0 −17
Original line number Diff line number Diff line
@@ -401,23 +401,6 @@ static inline struct hfsplus_inode_info *HFSPLUS_I(struct inode *inode) 
	return list_entry(inode, struct hfsplus_inode_info, vfs_inode);

}



#define sb_bread512(sb, sec, data) ({			\

	struct buffer_head *__bh;			\

	sector_t __block;				\

	loff_t __start;					\

	int __offset;					\

							\

	__start = (loff_t)(sec) << HFSPLUS_SECTOR_SHIFT;\

	__block = __start >> (sb)->s_blocksize_bits;	\

	__offset = __start & ((sb)->s_blocksize - 1);	\

	__bh = sb_bread((sb), __block);			\

	if (likely(__bh != NULL))			\

		data = (void *)(__bh->b_data + __offset);\

	else						\

		data = NULL;				\

	__bh;						\

})



/* time macros */

#define __hfsp_mt2ut(t)		(be32_to_cpu(t) - 2082844800U)

#define __hfsp_ut2mt(t)		(cpu_to_be32(t + 2082844800U))

fs/hfsplus/part_tbl.c

+71 −53
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 *

 */



#include <linux/slab.h>

#include "hfsplus_fs.h"



/* offsets to various blocks */
@@ -65,70 +66,87 @@ struct old_pmap { 
	}	pdEntry[42];

} __packed;



/*

 * hfs_part_find()

 *

 * Parse the partition map looking for the

 * start and length of the 'part'th HFS partition.

 */

int hfs_part_find(struct super_block *sb,

static int hfs_parse_old_pmap(struct super_block *sb, struct old_pmap *pm,

		sector_t *part_start, sector_t *part_size)

{

	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);

	struct buffer_head *bh;

	__be16 *data;

	int i, size, res;

	int i;



	res = -ENOENT;

	bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data);

	if (!bh)

		return -EIO;

	for (i = 0; i < 42; i++) {

		struct old_pmap_entry *p = &pm->pdEntry[i];



	switch (be16_to_cpu(*data)) {

	case HFS_OLD_PMAP_MAGIC:

	  {

		struct old_pmap *pm;

		struct old_pmap_entry *p;



		pm = (struct old_pmap *)bh->b_data;

		p = pm->pdEntry;

		size = 42;

		for (i = 0; i < size; p++, i++) {

		if (p->pdStart && p->pdSize &&

		    p->pdFSID == cpu_to_be32(0x54465331)/*"TFS1"*/ &&

		    (sbi->part < 0 || sbi->part == i)) {

			*part_start += be32_to_cpu(p->pdStart);

			*part_size = be32_to_cpu(p->pdSize);

				res = 0;

			return 0;

		}

	}

		break;



	return -ENOENT;

}

	case HFS_NEW_PMAP_MAGIC:



static int hfs_parse_new_pmap(struct super_block *sb, struct new_pmap *pm,

		sector_t *part_start, sector_t *part_size)

{

		struct new_pmap *pm;

	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);

	int size = be32_to_cpu(pm->pmMapBlkCnt);

	int res;

	int i = 0;



		pm = (struct new_pmap *)bh->b_data;

		size = be32_to_cpu(pm->pmMapBlkCnt);

		for (i = 0; i < size;) {

	do {

		if (!memcmp(pm->pmPartType,"Apple_HFS", 9) &&

		    (sbi->part < 0 || sbi->part == i)) {

			*part_start += be32_to_cpu(pm->pmPyPartStart);

			*part_size = be32_to_cpu(pm->pmPartBlkCnt);

				res = 0;

				break;

			return 0;

		}

			brelse(bh);

			bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK + ++i, pm);

			if (!bh)

				return -EIO;

			if (pm->pmSig != cpu_to_be16(HFS_NEW_PMAP_MAGIC))

				break;



		if (++i >= size)

			return -ENOENT;



		res = hfsplus_submit_bio(sb->s_bdev,

					 *part_start + HFS_PMAP_BLK + i,

					 pm, READ);

		if (res)

			return res;

	} while (pm->pmSig == cpu_to_be16(HFS_NEW_PMAP_MAGIC));



	return -ENOENT;

}



/*

 * Parse the partition map looking for the start and length of a

 * HFS/HFS+ partition.

 */

int hfs_part_find(struct super_block *sb,

		sector_t *part_start, sector_t *part_size)

{

	void *data;

	int res;



	data = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	res = hfsplus_submit_bio(sb->s_bdev, *part_start + HFS_PMAP_BLK,

				 data, READ);

	if (res)

		return res;



	switch (be16_to_cpu(*((__be16 *)data))) {

	case HFS_OLD_PMAP_MAGIC:

		res = hfs_parse_old_pmap(sb, data, part_start, part_size);

		break;

	case HFS_NEW_PMAP_MAGIC:

		res = hfs_parse_new_pmap(sb, data, part_start, part_size);

		break;

	default:

		res = -ENOENT;

		break;

	}

	}

	brelse(bh);



	kfree(data);

	return res;

}