diff options
author | Christoph Hellwig <hch@tuxera.com> | 2010-11-23 14:37:51 +0100 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2010-11-23 14:37:51 +0100 |
commit | 358f26d52680cb150907302d4334359de7dd2d59 (patch) | |
tree | 9348f861b49d5dd51049e31971cc09ab151388bc /fs/hfsplus/part_tbl.c | |
parent | 52399b171dfaea02b6944cd6feba49b624147126 (diff) |
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: Christoph Hellwig <hch@tuxera.com>
Diffstat (limited to 'fs/hfsplus/part_tbl.c')
-rw-r--r-- | fs/hfsplus/part_tbl.c | 124 |
1 files changed, 71 insertions, 53 deletions
diff --git a/fs/hfsplus/part_tbl.c b/fs/hfsplus/part_tbl.c index 208b16c645c..58918222a60 100644 --- a/fs/hfsplus/part_tbl.c +++ b/fs/hfsplus/part_tbl.c @@ -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; +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; +} + +static int hfs_parse_new_pmap(struct super_block *sb, 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 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; + + 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; +} + /* - * hfs_part_find() - * - * Parse the partition map looking for the - * start and length of the 'part'th HFS partition. + * 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) + 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; + void *data; + int res; + + data = kmalloc(HFSPLUS_SECTOR_SIZE, GFP_KERNEL); + if (!data) + return -ENOMEM; - res = -ENOENT; - bh = sb_bread512(sb, *part_start + HFS_PMAP_BLK, data); - if (!bh) - return -EIO; + res = hfsplus_submit_bio(sb->s_bdev, *part_start + HFS_PMAP_BLK, + data, READ); + if (res) + return res; - switch (be16_to_cpu(*data)) { + switch (be16_to_cpu(*((__be16 *)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; - } - } + res = hfs_parse_old_pmap(sb, data, part_start, part_size); 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) && - (sbi->part < 0 || sbi->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; - } + res = hfs_parse_new_pmap(sb, data, part_start, part_size); + break; + default: + res = -ENOENT; break; - } } - brelse(bh); + kfree(data); return res; } |