/* * linux/fs/hfs/part_tbl.c * * Copyright (C) 1996-1997 Paul H. Hargrove * (C) 2003 Ardis Technologies * 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; } 9d7e63e41459eba106cce30f3'>trace/events/v4l2.h
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