Message-ID: <20110901003153.31048.982.stgit@elm3c44.beaverton.ibm.com>
Date:	Wed, 31 Aug 2011 17:31:53 -0700
From:	"Darrick J. Wong" <djwong@...ibm.com>
To:	Andreas Dilger <adilger.kernel@...ger.ca>,
	Theodore Tso <tytso@....edu>,
	"Darrick J. Wong" <djwong@...ibm.com>
Cc:	Sunil Mushran <sunil.mushran@...cle.com>,
	Amir Goldstein <amir73il@...il.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Andi Kleen <andi@...stfloor.org>,
	Mingming Cao <cmm@...ibm.com>,
	Joel Becker <jlbec@...lplan.org>,
	linux-fsdevel <linux-fsdevel@...r.kernel.org>,
	linux-ext4@...r.kernel.org, Coly Li <colyli@...il.com>
Subject: [PATCH 12/16] ext4: Calculate and verify checksums of directory leaf
	blocks

Calculate and verify the checksums for directory leaf blocks (i.e. blocks that
only contain actual directory entries).  The checksum lives in what looks to be
an unused directory entry with a 0 name_len at the end of the block.  This
scheme is not used for internal htree nodes because the mechanism in place
there only costs one dx_entry, whereas the "empty" directory entry would cost
two dx_entries.

Signed-off-by: Darrick J. Wong <djwong@...ibm.com>
---
 fs/ext4/dir.c   |   12 +++
 fs/ext4/ext4.h  |   13 +++
 fs/ext4/namei.c |  259 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 269 insertions(+), 15 deletions(-)


diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 164c560..bc40c9e 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -180,6 +180,18 @@ static int ext4_readdir(struct file *filp,
 			continue;
 		}
 
+		/* Check the checksum */
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(inode,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_FILE(filp, 0, "directory fails checksum "
+					"at offset %llu",
+					(unsigned long long)filp->f_pos);
+			filp->f_pos += sb->s_blocksize - offset;
+			continue;
+		}
+		set_buffer_verified(bh);
+
 revalidate:
 		/* If the dir block has changed since the last call to
 		 * readdir(2), then we might be pointing to an invalid
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index df149b3..b7aa5b5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1471,6 +1471,17 @@ struct ext4_dir_entry_2 {
 };
 
 /*
+ * This is a bogus directory entry at the end of each leaf block that
+ * records checksums.
+ */
+struct ext4_dir_entry_tail {
+	__le32	reserved_zero1;		/* Pretend to be unused */
+	__le16	rec_len;		/* 12 */
+	__le16	reserved_zero2;		/* Zero name length */
+	__le32	checksum;		/* crc32c(uuid+inum+dirblock) */
+};
+
+/*
  * Ext4 directory file types.  Only the low 3 bits are used.  The
  * other bits are reserved for now.
  */
@@ -1875,6 +1886,8 @@ extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
 extern int ext4_ext_migrate(struct inode *);
 
 /* namei.c */
+extern int ext4_dirent_csum_verify(struct inode *inode,
+				   struct ext4_dir_entry *dirent);
 extern int ext4_orphan_add(handle_t *, struct inode *);
 extern int ext4_orphan_del(handle_t *, struct inode *);
 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 89797bf..2d0fdb9 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -191,6 +191,104 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			     struct inode *inode);
 
 /* checksumming functions */
+static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
+						   struct ext4_dir_entry *de)
+{
+	struct ext4_dir_entry *d, *top;
+	struct ext4_dir_entry_tail *t;
+
+	d = de;
+	top = (struct ext4_dir_entry *)(((void *)de) +
+		(EXT4_BLOCK_SIZE(inode->i_sb) -
+		sizeof(struct ext4_dir_entry_tail)));
+	while (d < top && d->rec_len)
+		d = (struct ext4_dir_entry *)(((void *)d) +
+		    le16_to_cpu(d->rec_len));
+
+	if (d != top)
+		return NULL;
+
+	t = (struct ext4_dir_entry_tail *)d;
+	if (t->reserved_zero1 ||
+	    le16_to_cpu(t->rec_len) != sizeof(struct ext4_dir_entry_tail) ||
+	    t->reserved_zero2)
+		return NULL;
+
+	return t;
+}
+
+static __le32 ext4_dirent_csum(struct inode *inode,
+			       struct ext4_dir_entry *dirent)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	struct ext4_dir_entry_tail *t;
+	__le32 inum = cpu_to_le32(inode->i_ino);
+	int size;
+	__u32 crc = 0;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 0;
+
+	t = get_dirent_tail(inode, dirent);
+	if (!t)
+		return 0;
+
+	size = (void *)t - (void *)dirent;
+	crc = crc32c_le(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
+	crc = crc32c_le(crc, (__u8 *)&inum, sizeof(inum));
+	crc = crc32c_le(crc, (__u8 *)dirent, size);
+	return cpu_to_le32(crc);
+}
+
+int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	t = get_dirent_tail(inode, dirent);
+	if (!t) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
+				 "leaf for checksum.  Please run e2fsck -D.");
+		return 0;
+	}
+
+	if (t->checksum != ext4_dirent_csum(inode, dirent))
+		return 0;
+
+	return 1;
+}
+
+static void ext4_dirent_csum_set(struct inode *inode,
+				 struct ext4_dir_entry *dirent)
+{
+	struct ext4_dir_entry_tail *t;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+					EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	t = get_dirent_tail(inode, dirent);
+	if (!t) {
+		EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
+				 "leaf for checksum.  Please run e2fsck -D.");
+		return;
+	}
+
+	t->checksum = ext4_dirent_csum(inode, dirent);
+}
+
+static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
+						struct inode *inode,
+						struct buffer_head *bh)
+{
+	ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
+	return ext4_handle_dirty_metadata(handle, inode, bh);
+}
+
 static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
 					       struct ext4_dir_entry *dirent,
 					       int *offset)
@@ -748,6 +846,11 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 		return err;
 
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
+		return -EIO;
+	set_buffer_verified(bh);
+
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	top = (struct ext4_dir_entry_2 *) ((char *) de +
 					   dir->i_sb->s_blocksize -
@@ -1106,6 +1209,15 @@ restart:
 			brelse(bh);
 			goto next;
 		}
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_INODE(dir, "checksumming directory "
+					 "block %lu", (unsigned long)block);
+			brelse(bh);
+			goto next;
+		}
+		set_buffer_verified(bh);
 		i = search_dirblock(bh, dir, d_name,
 			    block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 		if (i == 1) {
@@ -1157,6 +1269,16 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
 		if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
 			goto errout;
 
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data)) {
+			EXT4_ERROR_INODE(dir, "checksumming directory "
+					 "block %lu", (unsigned long)block);
+			brelse(bh);
+			*err = -EIO;
+			goto errout;
+		}
+		set_buffer_verified(bh);
 		retval = search_dirblock(bh, dir, d_name,
 					 block << EXT4_BLOCK_SIZE_BITS(sb),
 					 res_dir);
@@ -1329,8 +1451,14 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	char *data1 = (*bh)->b_data, *data2;
 	unsigned split, move, size;
 	struct ext4_dir_entry_2 *de = NULL, *de2;
+	struct ext4_dir_entry_tail *t;
+	int	csum_size = 0;
 	int	err = 0, i;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	bh2 = ext4_append (handle, dir, &newblock, &err);
 	if (!(bh2)) {
 		brelse(*bh);
@@ -1377,10 +1505,24 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	/* Fancy dance to stay within two buffers */
 	de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
 	de = dx_pack_dirents(data1, blocksize);
-	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
+					   (char *) de,
 					   blocksize);
-	de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
+	de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
+					    (char *) de2,
 					    blocksize);
+	if (csum_size) {
+		t = (struct ext4_dir_entry_tail *)(data2 +
+						   (blocksize - csum_size));
+		memset(t, 0, csum_size);
+		t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
+
+		t = (struct ext4_dir_entry_tail *)(data1 +
+						   (blocksize - csum_size));
+		memset(t, 0, csum_size);
+		t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
+	}
+
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
 
@@ -1391,7 +1533,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 		de = de2;
 	}
 	dx_insert_block(frame, hash2 + continued, newblock);
-	err = ext4_handle_dirty_metadata(handle, dir, bh2);
+	err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
 	if (err)
 		goto journal_error;
 	err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
@@ -1431,11 +1573,16 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	unsigned short	reclen;
 	int		nlen, rlen, err;
 	char		*top;
+	int		csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	reclen = EXT4_DIR_REC_LEN(namelen);
 	if (!de) {
 		de = (struct ext4_dir_entry_2 *)bh->b_data;
-		top = bh->b_data + blocksize - reclen;
+		top = bh->b_data + (blocksize - csum_size) - reclen;
 		while ((char *) de <= top) {
 			if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
 				return -EIO;
@@ -1491,7 +1638,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
 	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-	err = ext4_handle_dirty_metadata(handle, dir, bh);
+	err = ext4_handle_dirty_dirent_node(handle, dir, bh);
 	if (err)
 		ext4_std_error(dir->i_sb, err);
 	return 0;
@@ -1512,6 +1659,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	struct dx_frame	frames[2], *frame;
 	struct dx_entry *entries;
 	struct ext4_dir_entry_2	*de, *de2;
+	struct ext4_dir_entry_tail *t;
 	char		*data1, *top;
 	unsigned	len;
 	int		retval;
@@ -1519,6 +1667,11 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	struct dx_hash_info hinfo;
 	ext4_lblk_t  block;
 	struct fake_dirent *fde;
+	int		csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	blocksize =  dir->i_sb->s_blocksize;
 	dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
@@ -1539,7 +1692,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 		brelse(bh);
 		return -EIO;
 	}
-	len = ((char *) root) + blocksize - (char *) de;
+	len = ((char *) root) + (blocksize - csum_size) - (char *) de;
 
 	/* Allocate new block for the 0th block's dirents */
 	bh2 = ext4_append(handle, dir, &block, &retval);
@@ -1555,8 +1708,17 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	top = data1 + len;
 	while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
 		de = de2;
-	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
+	de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
+					   (char *) de,
 					   blocksize);
+
+	if (csum_size) {
+		t = (struct ext4_dir_entry_tail *)(data1 +
+						   (blocksize - csum_size));
+		memset(t, 0, csum_size);
+		t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
+	}
+
 	/* Initialize the root; the dot dirents already exist */
 	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
 	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
@@ -1582,7 +1744,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	bh = bh2;
 
 	ext4_handle_dirty_dx_node(handle, dir, frame->bh);
-	ext4_handle_dirty_metadata(handle, dir, bh);
+	ext4_handle_dirty_dirent_node(handle, dir, bh);
 
 	de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
 	if (!de) {
@@ -1618,11 +1780,17 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 	struct inode *dir = dentry->d_parent->d_inode;
 	struct buffer_head *bh;
 	struct ext4_dir_entry_2 *de;
+	struct ext4_dir_entry_tail *t;
 	struct super_block *sb;
 	int	retval;
 	int	dx_fallback=0;
 	unsigned blocksize;
 	ext4_lblk_t block, blocks;
+	int	csum_size = 0;
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
 
 	sb = dir->i_sb;
 	blocksize = sb->s_blocksize;
@@ -1641,6 +1809,11 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 		bh = ext4_bread(handle, dir, block, 0, &retval);
 		if(!bh)
 			return retval;
+		if (!buffer_verified(bh) &&
+		    !ext4_dirent_csum_verify(dir,
+				(struct ext4_dir_entry *)bh->b_data))
+			return -EIO;
+		set_buffer_verified(bh);
 		retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
 		if (retval != -ENOSPC) {
 			brelse(bh);
@@ -1657,7 +1830,15 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 		return retval;
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de->inode = 0;
-	de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
+	de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
+
+	if (csum_size) {
+		t = (struct ext4_dir_entry_tail *)(((void *)bh->b_data) +
+						   (blocksize - csum_size));
+		memset(t, 0, csum_size);
+		t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
+	}
+
 	retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
 	brelse(bh);
 	if (retval == 0)
@@ -1689,6 +1870,11 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 	if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
 		goto cleanup;
 
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
+		goto journal_error;
+	set_buffer_verified(bh);
+
 	BUFFER_TRACE(bh, "get_write_access");
 	err = ext4_journal_get_write_access(handle, bh);
 	if (err)
@@ -1814,12 +2000,17 @@ static int ext4_delete_entry(handle_t *handle,
 {
 	struct ext4_dir_entry_2 *de, *pde;
 	unsigned int blocksize = dir->i_sb->s_blocksize;
+	int csum_size = 0;
 	int i, err;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	i = 0;
 	pde = NULL;
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
-	while (i < bh->b_size) {
+	while (i < bh->b_size - csum_size) {
 		if (ext4_check_dir_entry(dir, NULL, de, bh, i))
 			return -EIO;
 		if (de == de_del)  {
@@ -1840,7 +2031,7 @@ static int ext4_delete_entry(handle_t *handle,
 				de->inode = 0;
 			dir->i_version++;
 			BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
-			err = ext4_handle_dirty_metadata(handle, dir, bh);
+			err = ext4_handle_dirty_dirent_node(handle, dir, bh);
 			if (unlikely(err)) {
 				ext4_std_error(dir->i_sb, err);
 				return err;
@@ -1983,9 +2174,15 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	struct inode *inode;
 	struct buffer_head *dir_block = NULL;
 	struct ext4_dir_entry_2 *de;
+	struct ext4_dir_entry_tail *t;
 	unsigned int blocksize = dir->i_sb->s_blocksize;
+	int csum_size = 0;
 	int err, retries = 0;
 
+	if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
+				       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		csum_size = sizeof(struct ext4_dir_entry_tail);
+
 	if (EXT4_DIR_LINK_MAX(dir))
 		return -EMLINK;
 
@@ -2026,16 +2223,26 @@ retry:
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 	de = ext4_next_entry(de, blocksize);
 	de->inode = cpu_to_le32(dir->i_ino);
-	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
+	de->rec_len = ext4_rec_len_to_disk(blocksize -
+					   (csum_size + EXT4_DIR_REC_LEN(1)),
 					   blocksize);
 	de->name_len = 2;
 	strcpy(de->name, "..");
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
 	inode->i_nlink = 2;
+
+	if (csum_size) {
+		t = (struct ext4_dir_entry_tail *)(((void *)dir_block->b_data) +
+						   (blocksize - csum_size));
+		memset(t, 0, csum_size);
+		t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
+	}
+
 	BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
-	err = ext4_handle_dirty_metadata(handle, inode, dir_block);
+	err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
 	if (err)
 		goto out_clear_inode;
+	set_buffer_verified(dir_block);
 	err = ext4_mark_inode_dirty(handle, inode);
 	if (!err)
 		err = ext4_add_entry(handle, dentry, inode);
@@ -2085,6 +2292,14 @@ static int empty_dir(struct inode *inode)
 				     inode->i_ino);
 		return 1;
 	}
+	if (!buffer_verified(bh) &&
+	    !ext4_dirent_csum_verify(inode,
+			(struct ext4_dir_entry *)bh->b_data)) {
+		EXT4_ERROR_INODE(inode, "checksum error reading directory "
+				 "lblock 0");
+		return -EIO;
+	}
+	set_buffer_verified(bh);
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de1 = ext4_next_entry(de, sb->s_blocksize);
 	if (le32_to_cpu(de->inode) != inode->i_ino ||
@@ -2116,6 +2331,14 @@ static int empty_dir(struct inode *inode)
 				offset += sb->s_blocksize;
 				continue;
 			}
+			if (!buffer_verified(bh) &&
+			    !ext4_dirent_csum_verify(inode,
+					(struct ext4_dir_entry *)bh->b_data)) {
+				EXT4_ERROR_INODE(inode, "checksum error "
+						 "reading directory lblock 0");
+				return -EIO;
+			}
+			set_buffer_verified(bh);
 			de = (struct ext4_dir_entry_2 *) bh->b_data;
 		}
 		if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
@@ -2616,6 +2839,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
 		if (!dir_bh)
 			goto end_rename;
+		if (!buffer_verified(dir_bh) &&
+		    !ext4_dirent_csum_verify(old_inode,
+				(struct ext4_dir_entry *)dir_bh->b_data))
+			goto end_rename;
+		set_buffer_verified(dir_bh);
 		if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
 				old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
 			goto end_rename;
@@ -2646,7 +2874,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 					ext4_current_time(new_dir);
 		ext4_mark_inode_dirty(handle, new_dir);
 		BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
-		retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
+		retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
 		if (unlikely(retval)) {
 			ext4_std_error(new_dir->i_sb, retval);
 			goto end_rename;
@@ -2700,7 +2928,8 @@ 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_metadata(handle, old_inode, dir_bh);
+		retval = ext4_handle_dirty_dirent_node(handle, old_inode,
+						       dir_bh);
 		if (retval) {
 			ext4_std_error(old_dir->i_sb, retval);
 			goto end_rename;

--
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