f2fs: avoid unneeded page release for correct _count of page (b9987a27) · Commits · 戴 / test

In find_fsync_dnodes() and recover_data(), our flow is like this: ->f2fs_submit_page_bio() -> f2fs_put_page() -> page_cache_release() ---- page->_count declined to zero. ->__free_pages() -> put_page_testzero() ---- page->_count will be declined again. We will get a segment fault in put_page_testzero when CONFIG_DEBUG_VM is on, or return MM with a bad page with wrong _count num. So let's just release this page. Signed-off-by:

Chao Yu <chao2.yu@samsung.com> Signed-off-by:

Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/recovery.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -145,7 +145,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info sbi, struct list_head head)

		err = f2fs_submit_page_bio(sbi, page, blkaddr, READ_SYNC);
		if (err)
		goto out;
		return err;

		lock_page(page);

		@@ -191,9 +191,10 @@ next:
		/* check next segment */
		blkaddr = next_blkaddr_of_node(page);
		}

		unlock_page(page);
		out:
		__free_pages(page, 0);

		return err;
		}

		@@ -388,7 +389,7 @@ static int recover_data(struct f2fs_sb_info *sbi,

		err = f2fs_submit_page_bio(sbi, page, blkaddr, READ_SYNC);
		if (err)
		goto out;
		return err;

		lock_page(page);

		@@ -412,8 +413,8 @@ next:
		/* check next segment */
		blkaddr = next_blkaddr_of_node(page);
		}

		unlock_page(page);
		out:
		__free_pages(page, 0);

		if (!err)

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