[RFC PATCH] Btrfs: btrfs_defrag_file() force use target extent size SZ_128KiB for compressed data

[RFC PATCH] Btrfs: btrfs_defrag_file() force use target extent size SZ_128KiB for compressed data

[Timofey Titovets]

Defrag heuristic use extent lengh as threshold,
kernel autodefrag use SZ_256KiB and btrfs-progs use SZ_32MiB as
target extent lengh.

Problem:
Compressed extents always have lengh at < 128KiB (BTRFS_MAX_COMPRESSED)
So btrfs_defrag_file() always rewrite all extents in defrag range.

Hot fix that by force set target extent size to BTRFS_MAX_COMPRESSED,
if file allowed to be compressed.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
---
 fs/btrfs/ioctl.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index be5bd81b3669..952364ff4108 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1232,6 +1232,26 @@ static int cluster_pages_for_defrag(struct inode *inode,
 
 }
 
+static inline int inode_use_compression(struct inode *inode)
+{
+	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+
+	/* force compress */
+	if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
+		return 1;
+	/* defrag ioctl */
+	if (BTRFS_I(inode)->defrag_compress)
+		return 1;
+	/* bad compression ratios */
+	if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
+		return 0;
+	if (btrfs_test_opt(fs_info, COMPRESS) ||
+	    BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
+	    BTRFS_I(inode)->prop_compress)
+		return 1;
+	return 0;
+}
+
 int btrfs_defrag_file(struct inode *inode, struct file *file,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_to_defrag)
@@ -1270,6 +1290,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
 			compress_type = range->compress_type;
 	}
 
+	if (inode_use_compression(inode))
+		extent_thresh = BTRFS_MAX_COMPRESSED;
+
 	if (extent_thresh == 0)
 		extent_thresh = SZ_256K;
 
-- 
2.15.1

Re: [RFC PATCH] Btrfs: btrfs_defrag_file() force use target extent size SZ_128KiB for compressed data

[Timofey Titovets]

Ignore that patch please, i will send another

2017-12-14 2:25 GMT+03:00 Timofey Titovets <nefelim4ag@gmail.com>:
> Defrag heuristic use extent lengh as threshold,
> kernel autodefrag use SZ_256KiB and btrfs-progs use SZ_32MiB as
> target extent lengh.
>
> Problem:
> Compressed extents always have lengh at < 128KiB (BTRFS_MAX_COMPRESSED)
> So btrfs_defrag_file() always rewrite all extents in defrag range.
>
> Hot fix that by force set target extent size to BTRFS_MAX_COMPRESSED,
> if file allowed to be compressed.
>
> Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
> ---
>  fs/btrfs/ioctl.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index be5bd81b3669..952364ff4108 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -1232,6 +1232,26 @@ static int cluster_pages_for_defrag(struct inode *inode,
>
>  }
>
> +static inline int inode_use_compression(struct inode *inode)
> +{
> +       struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
> +
> +       /* force compress */
> +       if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
> +               return 1;
> +       /* defrag ioctl */
> +       if (BTRFS_I(inode)->defrag_compress)
> +               return 1;
> +       /* bad compression ratios */
> +       if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
> +               return 0;
> +       if (btrfs_test_opt(fs_info, COMPRESS) ||
> +           BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
> +           BTRFS_I(inode)->prop_compress)
> +               return 1;
> +       return 0;
> +}
> +
>  int btrfs_defrag_file(struct inode *inode, struct file *file,
>                       struct btrfs_ioctl_defrag_range_args *range,
>                       u64 newer_than, unsigned long max_to_defrag)
> @@ -1270,6 +1290,9 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
>                         compress_type = range->compress_type;
>         }
>
> +       if (inode_use_compression(inode))
> +               extent_thresh = BTRFS_MAX_COMPRESSED;
> +
>         if (extent_thresh == 0)
>                 extent_thresh = SZ_256K;
>
> --
> 2.15.1



-- 
Have a nice day,
Timofey.