linux-kernel - [PATCH 1/2] f2fs: fix the potential mismatch between dir's i_size and i

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Date:	Tue, 04 Feb 2014 13:46:43 +0900
From:	Jaegeuk Kim <jaegeuk.kim@...sung.com>
To:	unlisted-recipients:; (no To-header on input)
Cc:	Jaegeuk Kim <jaegeuk.kim@...sung.com>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net
Subject: [PATCH 1/2] f2fs: fix the potential mismatch between dir's i_size and
 i_blocks

This is the erroneous scenario.

                             i_size    on-disk i_size    i_blocks
__f2fs_add_link()             4096           4096           2
 get_new_data_page            8192           4096           3
 -ENOSPC = init_inode_metadata
 checkpoint                     -            4096           3
 POR and reboot

__f2fs_add_link()             4096           4096           3
 page = get_new_data_page (page->index = 1 by NEW_ADDR)
 add a dentry to the page successfully

f2fs_rmdir()
 f2fs_empty_dir()             4096           4096           3
 f2fs_unlink() goes, since there is no valid dentry due to i_size = 4096.
 But, still there is one dentry in page->index = 1.

So this patch moves the code to write dir->i_size into on-disk i_size in order
to sync dir's i_size, on-disk i_size, and its i_blocks.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@...sung.com>
---
 fs/f2fs/dir.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 2b7c255..bfcb4ae 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -395,9 +395,6 @@ static void update_parent_metadata(struct inode *dir, struct inode *inode,
 		set_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
 	}
 
-	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR))
-		update_inode_page(dir);
-
 	if (is_inode_flag_set(F2FS_I(inode), FI_INC_LINK))
 		clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
 }
@@ -511,7 +508,10 @@ add_dentry:
 
 	update_parent_metadata(dir, inode, current_depth);
 fail:
-	clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	if (is_inode_flag_set(F2FS_I(dir), FI_UPDATE_DIR)) {
+		update_inode_page(dir);
+		clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR);
+	}
 	kunmap(dentry_page);
 	f2fs_put_page(dentry_page, 1);
 	return err;
-- 
1.8.4.474.g128a96c

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