[PATCH] ext3: add extent map support

On disk extents format:
/*
* this is extent on-disk structure
* it's used at the bottom of the tree
*/
struct ext3_extent {
__le32  ee_block;       /* first logical block extent covers */
__le16  ee_len;         /* number of blocks covered by extent */
__le16  ee_start_hi;    /* high 16 bits of physical block */
__le32  ee_start;       /* low 32 bigs of physical block */
};

Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 31 insertions, 2 deletions

diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index f582cd762caf..b61181aadcbb 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -178,8 +178,9 @@ struct ext4_group_desc
 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
+#define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 
-#define EXT4_FL_USER_VISIBLE            0x0003DFFF /* User visible flags */
+#define EXT4_FL_USER_VISIBLE            0x000BDFFF /* User visible flags */
 #define EXT4_FL_USER_MODIFIABLE         0x000380FF /* User modifiable flags */
 
 /*
@@ -384,6 +385,7 @@ struct ext4_inode {
 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
+#define EXT4_MOUNT_EXTENTS              0x400000 /* Extents support */
 
 /* Compatibility, for having both ext2_fs.h and ext4_fs.h included at once */
 #ifndef _LINUX_EXT2_FS_H
@@ -582,11 +584,13 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
 
 #define EXT4_FEATURE_COMPAT_SUPP        EXT2_FEATURE_COMPAT_EXT_ATTR
 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
-                                         EXT4_FEATURE_INCOMPAT_META_BG)
+                                         EXT4_FEATURE_INCOMPAT_META_BG| \
+                                         EXT4_FEATURE_INCOMPAT_EXTENTS)
 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
@@ -825,6 +829,9 @@ extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
 extern void ext4_truncate (struct inode *);
 extern void ext4_set_inode_flags(struct inode *);
 extern void ext4_set_aops(struct inode *inode);
+extern int ext4_writepage_trans_blocks(struct inode *);
+extern int ext4_block_truncate_page(handle_t *handle, struct page *page,
+                struct address_space *mapping, loff_t from);
 
 /* ioctl.c */
 extern int ext4_ioctl (struct inode *, struct file *, unsigned int,
@@ -879,6 +886,28 @@ extern struct inode_operations ext4_special_inode_operations;
 extern struct inode_operations ext4_symlink_inode_operations;
 extern struct inode_operations ext4_fast_symlink_inode_operations;
 
+/* extents.c */
+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,
+                        unsigned long max_blocks, struct buffer_head *bh_result,
+                        int create, int extend_disksize);
+extern void ext4_ext_truncate(struct inode *, struct page *);
+extern void ext4_ext_init(struct super_block *);
+extern void ext4_ext_release(struct super_block *);
+static inline int
+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);
+}
+
 
 #endif  /* __KERNEL__ */