Commit b368cc5e authored by Fengnan Chang's avatar Fengnan Chang Committed by Jaegeuk Kim
Browse files

f2fs: compress: fix overwrite may reduce compress ratio unproperly 



when overwrite only first block of cluster, since cluster is not full, it
will call f2fs_write_raw_pages when f2fs_write_multi_pages, and cause the
whole cluster become uncompressed eventhough data can be compressed.
this may will make random write bench score reduce a lot.

root# dd if=/dev/zero of=./fio-test bs=1M count=1

root# sync

root# echo 3 > /proc/sys/vm/drop_caches

root# f2fs_io get_cblocks ./fio-test

root# dd if=/dev/zero of=./fio-test bs=4K count=1 oflag=direct conv=notrunc

w/o patch:
root# f2fs_io get_cblocks ./fio-test
189

w/ patch:
root# f2fs_io get_cblocks ./fio-test
192

Signed-off-by: default avatarFengnan Chang <changfengnan@vivo.com>
Signed-off-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 71f2c820

fs/f2fs/compress.c

+19 −0
Original line number Diff line number Diff line
@@ -881,6 +881,25 @@ bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index) 
	return is_page_in_cluster(cc, index);

}



bool f2fs_all_cluster_page_loaded(struct compress_ctx *cc, struct pagevec *pvec,

				int index, int nr_pages)

{

	unsigned long pgidx;

	int i;



	if (nr_pages - index < cc->cluster_size)

		return false;



	pgidx = pvec->pages[index]->index;



	for (i = 1; i < cc->cluster_size; i++) {

		if (pvec->pages[index + i]->index != pgidx + i)

			return false;

	}



	return true;

}



static bool cluster_has_invalid_data(struct compress_ctx *cc)

{

	loff_t i_size = i_size_read(cc->inode);

fs/f2fs/data.c

+18 −18
Original line number Diff line number Diff line
@@ -3040,6 +3040,10 @@ static int f2fs_write_cache_pages(struct address_space *mapping, 
			need_readd = false;

#ifdef CONFIG_F2FS_FS_COMPRESSION

			if (f2fs_compressed_file(inode)) {

				void *fsdata = NULL;

				struct page *pagep;

				int ret2;



				ret = f2fs_init_compress_ctx(&cc);

				if (ret) {

					done = 1;
@@ -3058,10 +3062,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping, 
				if (unlikely(f2fs_cp_error(sbi)))

					goto lock_page;



				if (f2fs_cluster_is_empty(&cc)) {

					void *fsdata = NULL;

					struct page *pagep;

					int ret2;

				if (!f2fs_cluster_is_empty(&cc))

					goto lock_page;



				ret2 = f2fs_prepare_compress_overwrite(

							inode, &pagep,
@@ -3071,15 +3073,13 @@ static int f2fs_write_cache_pages(struct address_space *mapping, 
					done = 1;

					break;

				} else if (ret2 &&

						!f2fs_compress_write_end(inode,

								fsdata, page->index,

								1)) {

					(!f2fs_compress_write_end(inode,

						fsdata, page->index, 1) ||

					 !f2fs_all_cluster_page_loaded(&cc,

						&pvec, i, nr_pages))) {

					retry = 1;

					break;

				}

				} else {

					goto lock_page;

				}

			}

#endif

			/* give a priority to WB_SYNC threads */

fs/f2fs/f2fs.h

+2 −0
Original line number Diff line number Diff line
@@ -4052,6 +4052,8 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed, 
							block_t blkaddr);

bool f2fs_cluster_is_empty(struct compress_ctx *cc);

bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index);

bool f2fs_all_cluster_page_loaded(struct compress_ctx *cc, struct pagevec *pvec,

				int index, int nr_pages);

bool f2fs_sanity_check_cluster(struct dnode_of_data *dn);

void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page);

int f2fs_write_multi_pages(struct compress_ctx *cc,