On Fri, Aug 25, 2017 at 12:18:40PM +0300, Timofey Titovets wrote:
> Move heuristic to external file
> Implement compression workspaces support for
> heuristic resources
I think the file compression.c is suitable, there's not that much code
the heuristic adds and it its only related to compresession.
> Signed-off-by: Timofey Titovets <nefelim4ag@xxxxxxxxx>
> ---
> fs/btrfs/Makefile | 2 +-
> fs/btrfs/compression.c | 18 +++++--------
> fs/btrfs/compression.h | 7 ++++-
> fs/btrfs/heuristic.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 87 insertions(+), 13 deletions(-)
> create mode 100644 fs/btrfs/heuristic.c
>
> diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
> index 128ce17a80b0..6fa8479dff43 100644
> --- a/fs/btrfs/Makefile
> +++ b/fs/btrfs/Makefile
> @@ -9,7 +9,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
> export.o tree-log.o free-space-cache.o zlib.o lzo.o \
> compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
> reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
> - uuid-tree.o props.o hash.o free-space-tree.o
> + uuid-tree.o props.o hash.o free-space-tree.o heuristic.o
>
> btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
> btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
> index 883ecc58fd0d..f0aaf27bcc95 100644
> --- a/fs/btrfs/compression.c
> +++ b/fs/btrfs/compression.c
> @@ -704,6 +704,7 @@ static struct {
> static const struct btrfs_compress_op * const btrfs_compress_op[] = {
> &btrfs_zlib_compress,
> &btrfs_lzo_compress,
> + &btrfs_heuristic,
> };
>
> void __init btrfs_init_compress(void)
> @@ -1065,18 +1066,13 @@ int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
> */
> int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
> {
> - u64 index = start >> PAGE_SHIFT;
> - u64 end_index = end >> PAGE_SHIFT;
> - struct page *page;
> - int ret = 1;
> + int ret;
> + enum btrfs_compression_type type = BTRFS_HEURISTIC;
> + struct list_head *workspace = find_workspace(type);
>
> - while (index <= end_index) {
> - page = find_get_page(inode->i_mapping, index);
> - kmap(page);
> - kunmap(page);
> - put_page(page);
> - index++;
> - }
> + ret = btrfs_compress_op[type-1]->heuristic(workspace, inode,
> + start, end);
>
> + free_workspace(type, workspace);
> return ret;
> }
> diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h
> index 3b1b0ac15fdc..10e9ffa6dfa4 100644
> --- a/fs/btrfs/compression.h
> +++ b/fs/btrfs/compression.h
> @@ -99,7 +99,8 @@ enum btrfs_compression_type {
> BTRFS_COMPRESS_NONE = 0,
> BTRFS_COMPRESS_ZLIB = 1,
> BTRFS_COMPRESS_LZO = 2,
> - BTRFS_COMPRESS_TYPES = 2,
> + BTRFS_HEURISTIC = 3,
> + BTRFS_COMPRESS_TYPES = 3,
Compression cannot be another type, I get it's for the workspace
management, that would need to be managed in another way anyway.
> };
>
> struct btrfs_compress_op {
> @@ -123,10 +124,14 @@ struct btrfs_compress_op {
> struct page *dest_page,
> unsigned long start_byte,
> size_t srclen, size_t destlen);
> +
> + int (*heuristic)(struct list_head *workspace,
> + struct inode *inode, u64 start, u64 end);
> };
>
> extern const struct btrfs_compress_op btrfs_zlib_compress;
> extern const struct btrfs_compress_op btrfs_lzo_compress;
> +extern const struct btrfs_compress_op btrfs_heuristic;
>
> int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end);
>
> diff --git a/fs/btrfs/heuristic.c b/fs/btrfs/heuristic.c
> new file mode 100644
> index 000000000000..92f9335bafd4
> --- /dev/null
> +++ b/fs/btrfs/heuristic.c
> @@ -0,0 +1,73 @@
> +/*
> + * Copyright (c) 2017
> + * All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public
> + * License v2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * General Public License for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/types.h>
> +#include <linux/sizes.h>
> +#include <linux/pagemap.h>
> +#include <linux/string.h>
> +#include <linux/bio.h>
> +#include "compression.h"
> +
> +struct workspace {
> + struct list_head list;
> +};
> +
> +static void heuristic_free_workspace(struct list_head *ws)
> +{
> + struct workspace *workspace = list_entry(ws, struct workspace, list);
> + kfree(workspace);
> +}
> +
> +static struct list_head *heuristic_alloc_workspace(void)
> +{
> + struct workspace *workspace;
> +
> + workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
> + if (!workspace)
> + return ERR_PTR(-ENOMEM);
> +
> + INIT_LIST_HEAD(&workspace->list);
> +
> + return &workspace->list;
> +}
> +
> +static int heuristic(struct list_head *ws, struct inode *inode,
> + u64 start, u64 end)
> +{
> + struct page *page;
> + u64 index, index_end;
> +
> + index = start >> PAGE_SHIFT;
> + index_end = end >> PAGE_SHIFT;
> +
> + /* Don't miss unaligned end */
> + if (!IS_ALIGNED(end, PAGE_SIZE))
> + index_end++;
> +
> + for (; index < index_end; index++) {
> + page = find_get_page(inode->i_mapping, index);
> + kmap(page);
> + kunmap(page);
> + put_page(page);
> + }
> +
> + return 1;
> +}
> +
> +const struct btrfs_compress_op btrfs_heuristic = {
> + .alloc_workspace = heuristic_alloc_workspace,
> + .free_workspace = heuristic_free_workspace,
> + .heuristic = heuristic,
> +};
> --
> 2.14.1
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