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>

2 files changed, 71 insertions, 70 deletions

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index 276ddb0fd0fd..0d8532d96694 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -401,23 +401,6 @@ static inline struct hfsplus_inode_info *HFSPLUS_I(struct inode *inode)
         return list_entry(inode, struct hfsplus_inode_info, vfs_inode);
 }
 
-#define sb_bread512(sb, sec, data) ({                   \
-        struct buffer_head *__bh;                       \
-        sector_t __block;                               \
-        loff_t __start;                                 \
-        int __offset;                                   \
-                                                        \
-        __start = (loff_t)(sec) << HFSPLUS_SECTOR_SHIFT;\
-        __block = __start >> (sb)->s_blocksize_bits;    \
-        __offset = __start & ((sb)->s_blocksize - 1);   \
-        __bh = sb_bread((sb), __block);                 \
-        if (likely(__bh != NULL))                       \
-                data = (void *)(__bh->b_data + __offset);\
-        else                                            \
-                data = NULL;                            \
-        __bh;                                           \
-})
-
 /* time macros */
 #define __hfsp_mt2ut(t)         (be32_to_cpu(t) - 2082844800U)
 #define __hfsp_ut2mt(t)         (cpu_to_be32(t + 2082844800U))
diff --git a/fs/hfsplus/part_tbl.c b/fs/hfsplus/part_tbl.c
index 208b16c645cc..58918222a604 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;
 }