Btrfs: do not create explicit holes when replaying log tree if NO_HOLES enabled

Commit Message

Filipe Manana Feb. 1, 2017, 3:23 p.m. UTC

From: Filipe Manana <[e-mail]>

We log holes explicitly by using file extent items, however when replaying
a log tree, if a logged file extent item corresponds to a hole and the
NO_HOLES feature is enabled we do not need to copy the file extent item
into the fs/subvolume tree, as the absence of such file extent items is
the purpose of the NO_HOLES feature. So skip the copying of file extent
items representing holes when the NO_HOLES feature is enabled.

Signed-off-by: Filipe Manana <[e-mail]>
---
 fs/btrfs/tree-log.c | 5 +++++
 1 file changed, 5 insertions(+)

Patch

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index eeffff8..44aca7f 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -667,6 +667,10 @@  static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 	if (ret)
 		goto out;
 
+	if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
+	    btrfs_fs_incompat(fs_info, NO_HOLES))
+		goto update_inode;
+
 	if (found_type == BTRFS_FILE_EXTENT_REG ||
 	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 		u64 offset;
@@ -825,6 +829,7 @@  static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 	}
 
 	inode_add_bytes(inode, nbytes);
+update_inode:
 	ret = btrfs_update_inode(trans, root, inode);
 out:
 	if (inode)