[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, 11 insertions, 0 deletions

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 34d39ae966f7..e17a6c918d72 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -615,6 +615,17 @@ got:
                 ext4_std_error(sb, err);
                 goto fail_free_drop;
         }
+        if (test_opt(sb, EXTENTS)) {
+                EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
+                ext4_ext_tree_init(handle, inode);
+                if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
+                        err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
+                        if (err) goto fail;
+                        EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS);
+                        BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "call ext4_journal_dirty_metadata");
+                        err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
+                }
+        }
 
         ext4_debug("allocating inode %lu\n", inode->i_ino);
         goto really_out;