btrfs: add flushing states for handling data reservations

Currently the way we do data reservations is by seeing if we have enough
space in our space_info.  If we do not and we're a normal inode we'll

1) Attempt to force a chunk allocation until we can't anymore.
2) If that fails we'll flush delalloc, then commit the transaction, then
   run the delayed iputs.

If we are a free space inode we're only allowed to force a chunk
allocation.  In order to use the normal flushing mechanism we need to
encode this into a flush state array for normal inodes.  Since both will
start with allocating chunks until the space info is full there is no
need to add this as a flush state, this will be handled specially.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e2ec4f067857..098f006fc5a3 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2592,6 +2592,8 @@ enum btrfs_reserve_flush_enum {
 	 *
 	 * Can be interruped by fatal signal.
 	 */
+	BTRFS_RESERVE_FLUSH_DATA,
+	BTRFS_RESERVE_FLUSH_FREE_SPACE_INODE,
 	BTRFS_RESERVE_FLUSH_ALL,
 
 	/*