118 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			118 lines
		
	
	
	
		
			2.9 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  *  linux/fs/hfs/part_tbl.c | ||
|  |  * | ||
|  |  * Copyright (C) 1996-1997  Paul H. Hargrove | ||
|  |  * (C) 2003 Ardis Technologies <roman@ardistech.com> | ||
|  |  * This file may be distributed under the terms of the GNU General Public License. | ||
|  |  * | ||
|  |  * Original code to handle the new style Mac partition table based on | ||
|  |  * a patch contributed by Holger Schemel (aeglos@valinor.owl.de). | ||
|  |  */ | ||
|  | 
 | ||
|  | #include "hfs_fs.h"
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * The new style Mac partition map | ||
|  |  * | ||
|  |  * For each partition on the media there is a physical block (512-byte | ||
|  |  * block) containing one of these structures.  These blocks are | ||
|  |  * contiguous starting at block 1. | ||
|  |  */ | ||
|  | struct new_pmap { | ||
|  | 	__be16	pmSig;		/* signature */ | ||
|  | 	__be16	reSigPad;	/* padding */ | ||
|  | 	__be32	pmMapBlkCnt;	/* partition blocks count */ | ||
|  | 	__be32	pmPyPartStart;	/* physical block start of partition */ | ||
|  | 	__be32	pmPartBlkCnt;	/* physical block count of partition */ | ||
|  | 	u8	pmPartName[32];	/* (null terminated?) string
 | ||
|  | 				   giving the name of this | ||
|  | 				   partition */ | ||
|  | 	u8	pmPartType[32];	/* (null terminated?) string
 | ||
|  | 				   giving the type of this | ||
|  | 				   partition */ | ||
|  | 	/* a bunch more stuff we don't need */ | ||
|  | } __packed; | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * The old style Mac partition map | ||
|  |  * | ||
|  |  * The partition map consists for a 2-byte signature followed by an | ||
|  |  * array of these structures.  The map is terminated with an all-zero | ||
|  |  * one of these. | ||
|  |  */ | ||
|  | struct old_pmap { | ||
|  | 	__be16		pdSig;	/* Signature bytes */ | ||
|  | 	struct 	old_pmap_entry { | ||
|  | 		__be32	pdStart; | ||
|  | 		__be32	pdSize; | ||
|  | 		__be32	pdFSID; | ||
|  | 	}	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, | ||
|  | 		  sector_t *part_start, sector_t *part_size) | ||
|  | { | ||
|  | 	struct buffer_head *bh; | ||
|  | 	__be16 *data; | ||
|  | 	int i, size, res; | ||
|  | 
 | ||
|  | 	res = -ENOENT; | ||
|  | 	bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data); | ||
|  | 	if (!bh) | ||
|  | 		return -EIO; | ||
|  | 
 | ||
|  | 	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"*/ && | ||
|  | 			    (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) { | ||
|  | 				*part_start += be32_to_cpu(p->pdStart); | ||
|  | 				*part_size = be32_to_cpu(p->pdSize); | ||
|  | 				res = 0; | ||
|  | 			} | ||
|  | 		} | ||
|  | 		break; | ||
|  | 	  } | ||
|  | 	case HFS_NEW_PMAP_MAGIC: | ||
|  | 	  { | ||
|  | 		struct new_pmap *pm; | ||
|  | 
 | ||
|  | 		pm = (struct new_pmap *)bh->b_data; | ||
|  | 		size = be32_to_cpu(pm->pmMapBlkCnt); | ||
|  | 		for (i = 0; i < size;) { | ||
|  | 			if (!memcmp(pm->pmPartType,"Apple_HFS", 9) && | ||
|  | 			    (HFS_SB(sb)->part < 0 || HFS_SB(sb)->part == i)) { | ||
|  | 				*part_start += be32_to_cpu(pm->pmPyPartStart); | ||
|  | 				*part_size = be32_to_cpu(pm->pmPartBlkCnt); | ||
|  | 				res = 0; | ||
|  | 				break; | ||
|  | 			} | ||
|  | 			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; | ||
|  | 		} | ||
|  | 		break; | ||
|  | 	  } | ||
|  | 	} | ||
|  | 	brelse(bh); | ||
|  | 
 | ||
|  | 	return res; | ||
|  | } |