On Fri, Apr 01, 2016 at 02:34:59PM +0800, Qu Wenruo wrote:
> From: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
>
> 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 <quwenruo@xxxxxxxxxxxxxx>
> Signed-off-by: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
> ---
> 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
--
Mark Fasheh
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