xfs: set XBF_DONE on newly formatted btree block that are ready for writing

The btree bulkloading code calls xfs_buf_delwri_queue_here when it has
finished formatting a new btree block and wants to queue it to be
written to disk.  Once the new btree root has been committed, the blocks
(and hence the buffers) will be accessible to the rest of the
filesystem.  Mark each new buffer as DONE when adding it to the delwri
list so that the next btree traversal can skip reloading the contents
from disk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_btree_staging.c b/fs/xfs/libxfs/xfs_btree_staging.c
index 29e3f8ccb185..1c5f9ed70c3e 100644
--- a/fs/xfs/libxfs/xfs_btree_staging.c
+++ b/fs/xfs/libxfs/xfs_btree_staging.c
@@ -342,6 +342,12 @@ xfs_btree_bload_drop_buf(
 	if (*bpp == NULL)
 		return;
 
+	/*
+	 * Mark this buffer XBF_DONE (i.e. uptodate) so that a subsequent
+	 * xfs_buf_read will not pointlessly reread the contents from the disk.
+	 */
+	(*bpp)->b_flags |= XBF_DONE;
+
 	xfs_buf_delwri_queue_here(*bpp, buffers_list);
 	xfs_buf_relse(*bpp);
 	*bpp = NULL;