ext4: Introduce ext4_lblk_t

This patch adds a new data type ext4_lblk_t to represent
the logical file blocks.

This is the preparatory patch to support large files in ext4
The follow up patch with convert the ext4_inode i_blocks to
represent the number of blocks in file system block size. This
changes makes it possible to have a block number 2**32 -1 which
will result in overflow if the block number is represented by
signed long. This patch convert all the block number to type
ext4_lblk_t which is typedef to __u32

Also remove dead code ext4_ext_walk_space

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>

3 files changed, 27 insertions, 30 deletions

diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index fb31c1aba989..5e2da0974d16 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -935,11 +935,14 @@ extern unsigned long ext4_count_free (struct buffer_head *, unsigned);
 /* inode.c */
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
                 struct buffer_head *bh, ext4_fsblk_t blocknr);
-struct buffer_head * ext4_getblk (handle_t *, struct inode *, long, int, int *);
-struct buffer_head * ext4_bread (handle_t *, struct inode *, int, int, int *);
+struct buffer_head *ext4_getblk(handle_t *, struct inode *,
+                                                ext4_lblk_t, int, int *);
+struct buffer_head *ext4_bread(handle_t *, struct inode *,
+                                                ext4_lblk_t, int, int *);
 int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
-        sector_t iblock, unsigned long maxblocks, struct buffer_head *bh_result,
-        int create, int extend_disksize);
+                                ext4_lblk_t iblock, unsigned long maxblocks,
+                                struct buffer_head *bh_result,
+                                int create, int extend_disksize);
 
 extern void ext4_read_inode (struct inode *);
 extern int  ext4_write_inode (struct inode *, int);
@@ -1068,7 +1071,7 @@ extern const struct inode_operations ext4_fast_symlink_inode_operations;
 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
 extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
-                        ext4_fsblk_t iblock,
+                        ext4_lblk_t iblock,
                         unsigned long max_blocks, struct buffer_head *bh_result,
                         int create, int extend_disksize);
 extern void ext4_ext_truncate(struct inode *, struct page *);
@@ -1081,11 +1084,17 @@ ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                         unsigned long max_blocks, struct buffer_head *bh,
                         int create, int extend_disksize)
 {
-        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-                return ext4_ext_get_blocks(handle, inode, block, max_blocks,
-                                        bh, create, extend_disksize);
-        return ext4_get_blocks_handle(handle, inode, block, max_blocks, bh,
-                                        create, extend_disksize);
+        int retval;
+        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
+                retval = ext4_ext_get_blocks(handle, inode,
+                                                (ext4_lblk_t)block, max_blocks,
+                                                bh, create, extend_disksize);
+        } else {
+                retval = ext4_get_blocks_handle(handle, inode,
+                                                (ext4_lblk_t)block, max_blocks,
+                                                bh, create, extend_disksize);
+        }
+        return retval;
 }
 
 
diff --git a/include/linux/ext4_fs_extents.h b/include/linux/ext4_fs_extents.h
index d2045a26195d..023683b9d883 100644
--- a/include/linux/ext4_fs_extents.h
+++ b/include/linux/ext4_fs_extents.h
@@ -124,20 +124,6 @@ struct ext4_ext_path {
 #define EXT4_EXT_CACHE_GAP      1
 #define EXT4_EXT_CACHE_EXTENT   2
 
-/*
- * to be called by ext4_ext_walk_space()
- * negative retcode - error
- * positive retcode - signal for ext4_ext_walk_space(), see below
- * callback must return valid extent (passed or newly created)
- */
-typedef int (*ext_prepare_callback)(struct inode *, struct ext4_ext_path *,
-                                        struct ext4_ext_cache *,
-                                        void *);
-
-#define EXT_CONTINUE    0
-#define EXT_BREAK       1
-#define EXT_REPEAT      2
-
 
 #define EXT_MAX_BLOCK   0xffffffff
 
@@ -233,8 +219,7 @@ extern int ext4_ext_try_to_merge(struct inode *inode,
                                  struct ext4_extent *);
 extern unsigned int ext4_ext_check_overlap(struct inode *, struct ext4_extent *, struct ext4_ext_path *);
 extern int ext4_ext_insert_extent(handle_t *, struct inode *, struct ext4_ext_path *, struct ext4_extent *);
-extern int ext4_ext_walk_space(struct inode *, unsigned long, unsigned long, ext_prepare_callback, void *);
-extern struct ext4_ext_path * ext4_ext_find_extent(struct inode *, int, struct ext4_ext_path *);
-
+extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
+                                                        struct ext4_ext_path *);
 #endif /* _LINUX_EXT4_EXTENTS */
 
diff --git a/include/linux/ext4_fs_i.h b/include/linux/ext4_fs_i.h
index 86ddfe2089f3..6c610b67b047 100644
--- a/include/linux/ext4_fs_i.h
+++ b/include/linux/ext4_fs_i.h
@@ -27,6 +27,9 @@ typedef int ext4_grpblk_t;
 /* data type for filesystem-wide blocks number */
 typedef unsigned long long ext4_fsblk_t;
 
+/* data type for file logical block number */
+typedef __u32 ext4_lblk_t;
+
 struct ext4_reserve_window {
         ext4_fsblk_t    _rsv_start;     /* First byte reserved */
         ext4_fsblk_t    _rsv_end;       /* Last byte reserved or 0 */
@@ -48,7 +51,7 @@ struct ext4_block_alloc_info {
          * most-recently-allocated block in this file.
          * We use this for detecting linearly ascending allocation requests.
          */
-        __u32 last_alloc_logical_block;
+        ext4_lblk_t last_alloc_logical_block;
         /*
          * Was i_next_alloc_goal in ext4_inode_info
          * is the *physical* companion to i_next_alloc_block.
@@ -67,7 +70,7 @@ struct ext4_block_alloc_info {
  */
 struct ext4_ext_cache {
         ext4_fsblk_t    ec_start;
-        __u32           ec_block;
+        ext4_lblk_t     ec_block;
         __u32           ec_len; /* must be 32bit to return holes */
         __u32           ec_type;
 };
@@ -95,7 +98,7 @@ struct ext4_inode_info {
         /* block reservation info */
         struct ext4_block_alloc_info *i_block_alloc_info;
 
-        __u32   i_dir_start_lookup;
+        ext4_lblk_t             i_dir_start_lookup;
 #ifdef CONFIG_EXT4DEV_FS_XATTR
         /*
          * Extended attributes can be read independently of the main file