linux-kernel - [PATCH v2 2/2] f2fs: compress: delay temp page allocation

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Date:   Sat, 25 Jul 2020 09:17:48 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     <jaegeuk@...nel.org>
CC:     <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>, <chao@...nel.org>,
        Chao Yu <yuchao0@...wei.com>
Subject: [PATCH v2 2/2] f2fs: compress: delay temp page allocation

Currently, we allocate temp pages which is used to pad hole in
cluster during read IO submission, it may take long time before
releasing them in f2fs_decompress_pages(), since they are only
used as temp output buffer in decompression context, so let's
just do the allocation in that context to reduce time of memory
pool resource occupation.

Signed-off-by: Chao Yu <yuchao0@...wei.com>
---
v2:
- fix to assign return value in error path
 fs/f2fs/compress.c | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index a20c9f3272af..6e7db450006c 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -670,6 +670,7 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
 	const struct f2fs_compress_ops *cops =
 			f2fs_cops[fi->i_compress_algorithm];
 	int ret;
+	int i;
 
 	dec_page_count(sbi, F2FS_RD_DATA);
 
@@ -688,6 +689,26 @@ void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
 		goto out_free_dic;
 	}
 
+	dic->tpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
+					dic->cluster_size, GFP_NOFS);
+	if (!dic->tpages) {
+		ret = -ENOMEM;
+		goto out_free_dic;
+	}
+
+	for (i = 0; i < dic->cluster_size; i++) {
+		if (dic->rpages[i]) {
+			dic->tpages[i] = dic->rpages[i];
+			continue;
+		}
+
+		dic->tpages[i] = f2fs_compress_alloc_page();
+		if (!dic->tpages[i]) {
+			ret = -ENOMEM;
+			goto out_free_dic;
+		}
+	}
+
 	if (cops->init_decompress_ctx) {
 		ret = cops->init_decompress_ctx(dic);
 		if (ret)
@@ -1449,22 +1470,6 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
 		dic->cpages[i] = page;
 	}
 
-	dic->tpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
-					dic->cluster_size, GFP_NOFS);
-	if (!dic->tpages)
-		goto out_free;
-
-	for (i = 0; i < dic->cluster_size; i++) {
-		if (cc->rpages[i]) {
-			dic->tpages[i] = cc->rpages[i];
-			continue;
-		}
-
-		dic->tpages[i] = f2fs_compress_alloc_page();
-		if (!dic->tpages[i])
-			goto out_free;
-	}
-
 	return dic;
 
 out_free:
-- 
2.26.2