[PATCH 1/2] ext4: use proper csum calculation in ext4_rename

[PATCH 1/2] ext4: use proper csum calculation in ext4_rename

[Theodore Ts'o]

From: Tao Ma <boyu.mt@taobao.com>

commit ef58f69c3c34f6377f1e21d3533c806dbd980ad0 upstream.

In ext4_rename, when the old name is a dir, we need to
change ".." to its new parent and journal the change, so
with metadata_csum enabled, we have to re-calc the csum.

As the first block of the dir can be either a htree root
or a normal directory block and we have different csum
calculation for these 2 types, we have to choose the right
one in ext4_rename.

btw, it is found by xfstests 013.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
---
[ Sorry, I forgot to tag these with stable@vger.kernel.org -- Ted ]

 fs/ext4/namei.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5845cd9..0edaf18 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2918,8 +2918,15 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
 						cpu_to_le32(new_dir->i_ino);
 		BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
-		retval = ext4_handle_dirty_dirent_node(handle, old_inode,
-						       dir_bh);
+		if (is_dx(old_inode)) {
+			retval = ext4_handle_dirty_dx_node(handle,
+							   old_inode,
+							   dir_bh);
+		} else {
+			retval = ext4_handle_dirty_dirent_node(handle,
+							       old_inode,
+							       dir_bh);
+		}
 		if (retval) {
 			ext4_std_error(old_dir->i_sb, retval);
 			goto end_rename;
-- 
1.7.12.rc0.22.gcdd159b

[PATCH 2/2] ext4: use s_csum_seed instead of i_csum_seed for xattr block

[Theodore Ts'o]

From: Tao Ma <boyu.mt@taobao.com>

commit 41eb70dde42b2360074a559a6f1fc49860a50179 upstream.

In xattr block operation, we use h_refcount to indicate whether the
xattr block is shared among many inodes. And xattr block csum uses
s_csum_seed if it is shared and i_csum_seed if it belongs to
one inode. But this has a problem. So consider the block is shared
first bewteen inode A and B, and B has some xattr update and CoW
the xattr block. When it updates the *old* xattr block(because
of the h_refcount change) and calls ext4_xattr_release_block, we
has no idea that inode A is the real owner of the *old* xattr
block and we can't use the i_csum_seed of inode A either in xattr
block csum calculation. And I don't think we have an easy way to
find inode A.

So this patch just removes the tricky i_csum_seed and we now uses
s_csum_seed every time for the xattr block csum. The corresponding
patch for the e2fsprogs will be sent in another patch.

This is spotted by xfstests 117.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
---
[ Sorry, I forgot to tag these with stable@vger.kernel.org -- Ted ]

 fs/ext4/xattr.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index e56c9ed..2cdb98d 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -127,19 +127,16 @@ static __le32 ext4_xattr_block_csum(struct inode *inode,
 				    struct ext4_xattr_header *hdr)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	struct ext4_inode_info *ei = EXT4_I(inode);
 	__u32 csum, old;
 
 	old = hdr->h_checksum;
 	hdr->h_checksum = 0;
-	if (le32_to_cpu(hdr->h_refcount) != 1) {
-		block_nr = cpu_to_le64(block_nr);
-		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&block_nr,
-				   sizeof(block_nr));
-	} else
-		csum = ei->i_csum_seed;
+	block_nr = cpu_to_le64(block_nr);
+	csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&block_nr,
+			   sizeof(block_nr));
 	csum = ext4_chksum(sbi, csum, (__u8 *)hdr,
 			   EXT4_BLOCK_SIZE(inode->i_sb));
+
 	hdr->h_checksum = old;
 	return cpu_to_le32(csum);
 }
-- 
1.7.12.rc0.22.gcdd159b