At 06/02/2016 06:06 AM, Mark Fasheh wrote:

On Fri, Apr 01, 2016 at 02:34:59PM +0800, Qu Wenruo wrote:

quoted

From: Wang Xiaoguang <redacted>

Add ordered-extent support for dedupe.

Note, current ordered-extent support only supports non-compressed source
extent.
Support for compressed source extent will be added later.

Signed-off-by: Qu Wenruo <redacted>
Signed-off-by: Wang Xiaoguang <redacted>
---
 fs/btrfs/ordered-data.c | 44 ++++++++++++++++++++++++++++++++++++++++----
 fs/btrfs/ordered-data.h | 13 +++++++++++++
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index 0de7da5..ef24ad1 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c

@@ -26,6 +26,7 @@
 #include "extent_io.h"
 #include "disk-io.h"
 #include "compression.h"
+#include "dedupe.h"

 static struct kmem_cache *btrfs_ordered_extent_cache;

@@ -184,7 +185,8 @@ static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
  */
 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 				      u64 start, u64 len, u64 disk_len,
-				      int type, int dio, int compress_type)
+				      int type, int dio, int compress_type,
+				      struct btrfs_dedupe_hash *hash)
 {
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_ordered_inode_tree *tree;

@@ -204,6 +206,31 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 	entry->inode = igrab(inode);
 	entry->compress_type = compress_type;
 	entry->truncated_len = (u64)-1;
+	entry->hash = NULL;
+	/*
+	 * Hash hit must go through dedupe routine at all cost, even dedupe
+	 * is disabled. As its delayed ref is already increased.
+	 */

Initially, I had a hard time understanding this comment but I'm pretty sure
I know what you mean.

/*
 * A hash hit means we have already incremented the extents delayed ref.
 * We must handle this even if another process raced to turn off dedupe
 * otherwise we might leak a reference.
 */

might be better. Hope that helps.
	--Mark

Same meaning, much better grammar.

Thanks,
Qu

--
Mark Fasheh