linux-ext4 - [PATCH] ext4: keep existing extra fields when inode expands

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Date:   Fri, 19 May 2017 10:13:39 +0300
From:   Konstantin Khlebnikov <khlebnikov@...dex-team.ru>
To:     Andreas Dilger <adilger.kernel@...ger.ca>,
        linux-ext4@...r.kernel.org, Theodore Ts'o <tytso@....edu>,
        linux-kernel@...r.kernel.org
Subject: [PATCH] ext4: keep existing extra fields when inode expands

ext4_expand_extra_isize() should clear only space between old and new size.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@...dex-team.ru>
---
 fs/ext4/inode.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5834c4d76be8..7204e1a2801a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5637,8 +5637,9 @@ static int ext4_expand_extra_isize(struct inode *inode,
 	/* No extended attributes present */
 	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
 	    header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
-		memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
-			new_extra_isize);
+		memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
+		       EXT4_I(inode)->i_extra_isize, 0,
+		       new_extra_isize - EXT4_I(inode)->i_extra_isize);
 		EXT4_I(inode)->i_extra_isize = new_extra_isize;
 		return 0;
 	}