hfsplus: use raw bio access for the volume headers

The hfsplus backup volume header is located two blocks from the end of
the device.  In case of device sizes that are not 4k aligned this means
we can't access it using buffer_heads when using the default 4k block
size.

Switch to using raw bios to read/write all buffer headers.  We were not
relying on any caching behaviour of the buffer heads anyway.  Additionally
always read in the backup volume header during mount to verify that we
can actually read it.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/hfsplus/hfsplus_fs.h b/fs/hfsplus/hfsplus_fs.h
index f07aa640c27d..276ddb0fd0fd 100644
--- a/fs/hfsplus/hfsplus_fs.h
+++ b/fs/hfsplus/hfsplus_fs.h
@@ -107,8 +107,8 @@ struct hfsplus_vh;
 struct hfs_btree;
 
 struct hfsplus_sb_info {
-        struct buffer_head *s_vhbh;
         struct hfsplus_vh *s_vhdr;
+        struct hfsplus_vh *s_backup_vhdr;
         struct hfs_btree *ext_tree;
         struct hfs_btree *cat_tree;
         struct hfs_btree *attr_tree;
@@ -118,7 +118,8 @@ struct hfsplus_sb_info {
 
         /* Runtime variables */
         u32 blockoffset;
-        u32 sect_count;
+        sector_t part_start;
+        sector_t sect_count;
         int fs_shift;
 
         /* immutable data from the volume header */
@@ -385,8 +386,9 @@ int hfsplus_compare_dentry(struct dentry *dentry, struct qstr *s1, struct qstr *
 
 /* wrapper.c */
 int hfsplus_read_wrapper(struct super_block *);
-
 int hfs_part_find(struct super_block *, sector_t *, sector_t *);
+int hfsplus_submit_bio(struct block_device *bdev, sector_t sector,
+                void *data, int rw);
 
 /* access macros */
 static inline struct hfsplus_sb_info *HFSPLUS_SB(struct super_block *sb)