Btrfs: map the inode item when doing fill_inode_item
Instead of calling kmap_atomic for every thing we set in the inode item, map the
entire inode item at the start and unmap it at the end. This makes a sequential
dd of 400mb O_DIRECT something like 1% faster. Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cc60228..da26802 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2589,6 +2589,13 @@
struct btrfs_inode_item *item,
struct inode *inode)
{
+ if (!leaf->map_token)
+ map_private_extent_buffer(leaf, (unsigned long)item,
+ sizeof(struct btrfs_inode_item),
+ &leaf->map_token, &leaf->kaddr,
+ &leaf->map_start, &leaf->map_len,
+ KM_USER1);
+
btrfs_set_inode_uid(leaf, item, inode->i_uid);
btrfs_set_inode_gid(leaf, item, inode->i_gid);
btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
@@ -2617,6 +2624,11 @@
btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
+
+ if (leaf->map_token) {
+ unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
+ leaf->map_token = NULL;
+ }
}
/*