1 files changed, 79 insertions, 12 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index abcdeab67f52..91341ec6e06a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -52,6 +52,46 @@
 #define EXT4_EXT_MARK_UNINIT1	0x2  /* mark first half uninitialized */
 #define EXT4_EXT_MARK_UNINIT2	0x4  /* mark second half uninitialized */
 
+static __le32 ext4_extent_block_csum(struct inode *inode,
+				     struct ext4_extent_header *eh)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	__u32 csum;
+
+	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
+			   EXT4_EXTENT_TAIL_OFFSET(eh));
+	return cpu_to_le32(csum);
+}
+
+static int ext4_extent_block_csum_verify(struct inode *inode,
+					 struct ext4_extent_header *eh)
+{
+	struct ext4_extent_tail *et;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return 1;
+
+	et = find_ext4_extent_tail(eh);
+	if (et->et_checksum != ext4_extent_block_csum(inode, eh))
+		return 0;
+	return 1;
+}
+
+static void ext4_extent_block_csum_set(struct inode *inode,
+				       struct ext4_extent_header *eh)
+{
+	struct ext4_extent_tail *et;
+
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
+		EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+		return;
+
+	et = find_ext4_extent_tail(eh);
+	et->et_checksum = ext4_extent_block_csum(inode, eh);
+}
+
 static int ext4_split_extent(handle_t *handle,
 				struct inode *inode,
 				struct ext4_ext_path *path,
@@ -117,6 +157,7 @@ static int __ext4_ext_dirty(const char *where, unsigned int line,
 {
 	int err;
 	if (path->p_bh) {
+		ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
 		/* path points to block */
 		err = __ext4_handle_dirty_metadata(where, line, handle,
 						   inode, path->p_bh);
@@ -391,6 +432,12 @@ static int __ext4_ext_check(const char *function, unsigned int line,
 		error_msg = "invalid extent entries";
 		goto corrupted;
 	}
+	/* Verify checksum on non-root extent tree nodes */
+	if (ext_depth(inode) != depth &&
+	    !ext4_extent_block_csum_verify(inode, eh)) {
+		error_msg = "extent tree corrupted";
+		goto corrupted;
+	}
 	return 0;
 
 corrupted:
@@ -412,6 +459,26 @@ int ext4_ext_check_inode(struct inode *inode)
 	return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
 }
 
+static int __ext4_ext_check_block(const char *function, unsigned int line,
+				  struct inode *inode,
+				  struct ext4_extent_header *eh,
+				  int depth,
+				  struct buffer_head *bh)
+{
+	int ret;
+
+	if (buffer_verified(bh))
+		return 0;
+	ret = ext4_ext_check(inode, eh, depth);
+	if (ret)
+		return ret;
+	set_buffer_verified(bh);
+	return ret;
+}
+
+#define ext4_ext_check_block(inode, eh, depth, bh)	\
+	__ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
+
 #ifdef EXT_DEBUG
 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
 {
@@ -536,7 +603,7 @@ ext4_ext_binsearch_idx(struct inode *inode,
 	}
 
 	path->p_idx = l - 1;
-	ext_debug("  -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
+	ext_debug("  -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
 		  ext4_idx_pblock(path->p_idx));
 
 #ifdef CHECK_BINSEARCH
@@ -668,8 +735,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 	i = depth;
 	/* walk through the tree */
 	while (i) {
-		int need_to_validate = 0;
-
 		ext_debug("depth %d: num %d, max %d\n",
 			  ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
 
@@ -688,8 +753,6 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 				put_bh(bh);
 				goto err;
 			}
-			/* validate the extent entries */
-			need_to_validate = 1;
 		}
 		eh = ext_block_hdr(bh);
 		ppos++;
@@ -703,7 +766,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
 		path[ppos].p_hdr = eh;
 		i--;
 
-		if (need_to_validate && ext4_ext_check(inode, eh, i))
+		if (ext4_ext_check_block(inode, eh, i, bh))
 			goto err;
 	}
 
@@ -914,6 +977,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		le16_add_cpu(&neh->eh_entries, m);
 	}
 
+	ext4_extent_block_csum_set(inode, neh);
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
@@ -992,6 +1056,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 				sizeof(struct ext4_extent_idx) * m);
 			le16_add_cpu(&neh->eh_entries, m);
 		}
+		ext4_extent_block_csum_set(inode, neh);
 		set_buffer_uptodate(bh);
 		unlock_buffer(bh);
 
@@ -1089,6 +1154,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	else
 		neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
 	neh->eh_magic = EXT4_EXT_MAGIC;
+	ext4_extent_block_csum_set(inode, neh);
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
@@ -1344,7 +1410,8 @@ got_index:
 			return -EIO;
 		eh = ext_block_hdr(bh);
 		/* subtract from p_depth to get proper eh_depth */
-		if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+		if (ext4_ext_check_block(inode, eh,
+					 path->p_depth - depth, bh)) {
 			put_bh(bh);
 			return -EIO;
 		}
@@ -1357,7 +1424,7 @@ got_index:
 	if (bh == NULL)
 		return -EIO;
 	eh = ext_block_hdr(bh);
-	if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
+	if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
 		put_bh(bh);
 		return -EIO;
 	}
@@ -2644,8 +2711,8 @@ cont:
 				err = -EIO;
 				break;
 			}
-			if (ext4_ext_check(inode, ext_block_hdr(bh),
-							depth - i - 1)) {
+			if (ext4_ext_check_block(inode, ext_block_hdr(bh),
+							depth - i - 1, bh)) {
 				err = -EIO;
 				break;
 			}
@@ -4722,8 +4789,8 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
 
 	/* Now release the pages */
 	if (last_page_offset > first_page_offset) {
-		truncate_inode_pages_range(mapping, first_page_offset,
-					   last_page_offset-1);
+		truncate_pagecache_range(inode, first_page_offset,
+					 last_page_offset - 1);
 	}
 
 	/* finish any pending end_io work */