cregit-Linux how code gets into the kernel

Release 4.10 fs/hfs/part_tbl.c

Directory: fs/hfs
/*
 *  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; }

Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton20458.45%133.33%
pre-gitpre-git14441.26%133.33%
al viroal viro10.29%133.33%
Total349100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton21951.53%133.33%
pre-gitpre-git19646.12%133.33%
al viroal viro102.35%133.33%
Total425100.00%3100.00%
Directory: fs/hfs
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