Btrfs: many file_write fixes, inline data

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/ctree.h

@@ -73,6 +73,9 @@ struct btrfs_header {
 			       (sizeof(struct btrfs_disk_key) + sizeof(u64)))
 #define __BTRFS_LEAF_DATA_SIZE(bs) ((bs) - sizeof(struct btrfs_header))
 #define BTRFS_LEAF_DATA_SIZE(r) (__BTRFS_LEAF_DATA_SIZE(r->blocksize))
+#define BTRFS_MAX_INLINE_DATA_SIZE(r) (BTRFS_LEAF_DATA_SIZE(r) - \
+					sizeof(struct btrfs_item) - \
+					sizeof(struct btrfs_file_extent_item))
 
 struct buffer_head;
 /*
@@ -204,8 +207,12 @@ struct btrfs_root_item {
 	__le32 refs;
 } __attribute__ ((__packed__));
 
+#define BTRFS_FILE_EXTENT_REG 0
+#define BTRFS_FILE_EXTENT_INLINE 1
+
 struct btrfs_file_extent_item {
 	__le64 generation;
+	u8 type;
 	/*
 	 * disk space consumed by the extent, checksum blocks are included
 	 * in these numbers
@@ -862,6 +869,34 @@ static inline u8 *btrfs_leaf_data(struct btrfs_leaf *l)
 	return (u8 *)l->items;
 }
 
+static inline int btrfs_file_extent_type(struct btrfs_file_extent_item *e)
+{
+	return e->type;
+}
+static inline void btrfs_set_file_extent_type(struct btrfs_file_extent_item *e,
+					      u8 val)
+{
+	e->type = val;
+}
+
+static inline char *btrfs_file_extent_inline_start(struct
+						   btrfs_file_extent_item *e)
+{
+	return (char *)(&e->disk_blocknr);
+}
+
+static inline u32 btrfs_file_extent_calc_inline_size(u32 datasize)
+{
+	return (unsigned long)(&((struct
+		  btrfs_file_extent_item *)NULL)->disk_blocknr) + datasize;
+}
+
+static inline u32 btrfs_file_extent_inline_len(struct btrfs_item *e)
+{
+	struct btrfs_file_extent_item *fe = NULL;
+	return btrfs_item_size(e) - (unsigned long)(&fe->disk_blocknr);
+}
+
 static inline u64 btrfs_file_extent_disk_blocknr(struct btrfs_file_extent_item
 						 *e)
 {

fs/btrfs/disk-io.c

@@ -108,6 +108,12 @@ int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
 
 	int ret;
 
+	if (logical == 0) {
+		bh->b_bdev = NULL;
+		bh->b_blocknr = 0;
+		set_buffer_mapped(bh);
+		return 0;
+	}
 	root = root->fs_info->dev_root;
 	ret = radix_tree_gang_lookup(&root->fs_info->dev_radix,
 				     (void **)lookup,

fs/btrfs/extent-tree.c

@@ -111,6 +111,9 @@ int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 				continue;
 			fi = btrfs_item_ptr(buf_leaf, i,
 					    struct btrfs_file_extent_item);
+			if (btrfs_file_extent_type(fi) ==
+			    BTRFS_FILE_EXTENT_INLINE)
+				continue;
 			ret = btrfs_inc_extent_ref(trans, root,
 				    btrfs_file_extent_disk_blocknr(fi),
 				    btrfs_file_extent_disk_num_blocks(fi));
@@ -539,6 +542,8 @@ static int drop_leaf_ref(struct btrfs_trans_handle *trans,
 		if (btrfs_disk_key_type(key) != BTRFS_EXTENT_DATA_KEY)
 			continue;
 		fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
+		if (btrfs_file_extent_type(fi) == BTRFS_FILE_EXTENT_INLINE)
+			continue;
 		/*
 		 * FIXME make sure to insert a trans record that
 		 * repeats the snapshot del on crash

fs/btrfs/file-item.c

@@ -34,6 +34,7 @@ int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
 	btrfs_set_file_extent_offset(item, 0);
 	btrfs_set_file_extent_num_blocks(item, num_blocks);
 	btrfs_set_file_extent_generation(item, trans->transid);
+	btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
 	btrfs_mark_buffer_dirty(path->nodes[0]);
 
 	btrfs_release_path(root, path);