[6/6] btrfs: add more zeroout modes for clearing unused space

Commit Message

David Sterba April 20, 2018, 2:21 p.m. UTC

Signed-off-by: David Sterba <[e-mail]>
---
 fs/btrfs/extent-tree.c     | 12 +++++++++++-
 include/uapi/linux/btrfs.h |  5 +++++
 2 files changed, 16 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 285bace8e2c6..bd2ac5779998 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2046,9 +2046,19 @@  static int btrfs_issue_clear_op(struct block_device *bdev, u64 start, u64 size,
 	case BTRFS_CLEAR_OP_DISCARD:
 		return blkdev_issue_discard(bdev, start >> 9, size >> 9,
 				GFP_NOFS, flags);
+	case BTRFS_CLEAR_OP_ZERO_NOUNMAP:
+		flags = BLKDEV_ZERO_NOUNMAP;
+		goto zeroout;
+	case BTRFS_CLEAR_OP_ZERO_NOFALLBACK:
+		flags = BLKDEV_ZERO_NOFALLBACK;
+		goto zeroout;
+	case BTRFS_CLEAR_OP_ZERO_NOUNMAP_NOFALLBACK:
+		flags = BLKDEV_ZERO_NOUNMAP | BLKDEV_ZERO_NOFALLBACK;
+		/* fall through */
 	case BTRFS_CLEAR_OP_ZERO:
+zeroout:
 		return blkdev_issue_zeroout(bdev, start >> 9, size >> 9,
-				GFP_NOFS, 0);
+				GFP_NOFS, flags);
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 1becbb241e53..5d1f13045906 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -744,6 +744,11 @@  enum btrfs_clear_op_type {
 	BTRFS_CLEAR_OP_DISCARD = 0,
 	BTRFS_CLEAR_OP_ZERO,
 	BTRFS_CLEAR_OP_DISCARD_SECURE,
+
+	/* Fine tuning for clearing by zeros, see __blkdev_issue_zeroout */
+	BTRFS_CLEAR_OP_ZERO_NOUNMAP,
+	BTRFS_CLEAR_OP_ZERO_NOFALLBACK,
+	BTRFS_CLEAR_OP_ZERO_NOUNMAP_NOFALLBACK,
 	BTRFS_NR_CLEAR_OP_TYPES,
 };