cregit-Linux how code gets into the kernel

Release 4.10 fs/hfsplus/part_tbl.c

Directory: fs/hfsplus
/*
 * linux/fs/hfsplus/part_tbl.c
 *
 * Copyright (C) 1996-1997  Paul H. Hargrove
 * 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).
 *
 * In function preconditions the term "valid" applied to a pointer to
 * a structure means that the pointer is non-NULL and the structure it
 * points to has all fields initialized to consistent values.
 *
 */

#include <linux/slab.h>
#include "hfsplus_fs.h"

/* offsets to various blocks */

#define HFS_DD_BLK		0 
/* Driver Descriptor block */

#define HFS_PMAP_BLK		1 
/* First block of partition map */

#define HFS_MDB_BLK		2 
/* Block (w/i partition) of MDB */

/* magic numbers for various disk blocks */

#define HFS_DRVR_DESC_MAGIC	0x4552 
/* "ER": driver descriptor map */

#define HFS_OLD_PMAP_MAGIC	0x5453 
/* "TS": old-type partition map */

#define HFS_NEW_PMAP_MAGIC	0x504D 
/* "PM": new-type partition map */

#define HFS_SUPER_MAGIC		0x4244 
/* "BD": HFS MDB (super block) */

#define HFS_MFS_SUPER_MAGIC	0xD2D7 
/* MFS MDB (super block) */

/*
 * 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;


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); int i; for (i = 0; i < 42; i++) { struct old_pmap_entry *p = &pm->pdEntry[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); return 0; } } return -ENOENT; }

Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton8868.75%133.33%
christoph hellwigchristoph hellwig4031.25%266.67%
Total128100.00%3100.00%


static int hfs_parse_new_pmap(struct super_block *sb, void *buf, struct new_pmap *pm, sector_t *part_start, sector_t *part_size) { struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); int size = be32_to_cpu(pm->pmMapBlkCnt); int buf_size = hfsplus_min_io_size(sb); int res; int i = 0; 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); return 0; } if (++i >= size) return -ENOENT; pm = (struct new_pmap *)((u8 *)pm + HFSPLUS_SECTOR_SIZE); if ((u8 *)pm - (u8 *)buf >= buf_size) { res = hfsplus_submit_bio(sb, *part_start + HFS_PMAP_BLK + i, buf, (void **)&pm, REQ_OP_READ, 0); if (res) return res; } } while (pm->pmSig == cpu_to_be16(HFS_NEW_PMAP_MAGIC)); return -ENOENT; }

Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton9141.94%120.00%
christoph hellwigchristoph hellwig6831.34%240.00%
seth forsheeseth forshee5525.35%120.00%
michael christiemichael christie31.38%120.00%
Total217100.00%5100.00%

/* * 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 *buf, *data; int res; buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); if (!buf) return -ENOMEM; res = hfsplus_submit_bio(sb, *part_start + HFS_PMAP_BLK, buf, &data, REQ_OP_READ, 0); if (res) goto out; 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, buf, data, part_start, part_size); break; default: res = -ENOENT; break; } out: kfree(buf); return res; }

Contributors

PersonTokensPropCommitsCommitProp
christoph hellwigchristoph hellwig11478.08%120.00%
seth forsheeseth forshee1510.27%120.00%
andrew mortonandrew morton96.16%120.00%
chuck ebbertchuck ebbert53.42%120.00%
michael christiemichael christie32.05%120.00%
Total146100.00%5100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
andrew mortonandrew morton29548.20%112.50%
christoph hellwigchristoph hellwig22636.93%225.00%
seth forsheeseth forshee7011.44%112.50%
al viroal viro91.47%112.50%
michael christiemichael christie60.98%112.50%
chuck ebbertchuck ebbert50.82%112.50%
anton salikhmetovanton salikhmetov10.16%112.50%
Total612100.00%8100.00%
Directory: fs/hfsplus
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