From ecde2e30033219b8b2e777bd8618253d4613346f Mon Sep 17 00:00:00 2001
From: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Date: Thu, 16 Feb 2012 16:23:58 +0900
Subject: [PATCH] --- yaml --- r: 287894 b: refs/heads/master c:
 285190d99fef696ec8b0041787387f013cb71d67 h: refs/heads/master v: v3

---
 [refs]                       | 2 +-
 trunk/fs/btrfs/compression.c | 2 ++
 trunk/fs/btrfs/extent_io.c   | 2 +-
 trunk/fs/btrfs/volumes.c     | 2 +-
 4 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 539885c957ac..a6b4ce76447a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 600a45e1d5e376f679ff9ecc4ce9452710a6d27c
+refs/heads/master: 285190d99fef696ec8b0041787387f013cb71d67
diff --git a/trunk/fs/btrfs/compression.c b/trunk/fs/btrfs/compression.c
index 14f1c5a0b2d2..d02c27cd14c7 100644
--- a/trunk/fs/btrfs/compression.c
+++ b/trunk/fs/btrfs/compression.c
@@ -588,6 +588,8 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				   page_offset(bio->bi_io_vec->bv_page),
 				   PAGE_CACHE_SIZE);
 	read_unlock(&em_tree->lock);
+	if (!em)
+		return -EIO;
 
 	compressed_len = em->block_len;
 	cb = kmalloc(compressed_bio_size(root, compressed_len), GFP_NOFS);
diff --git a/trunk/fs/btrfs/extent_io.c b/trunk/fs/btrfs/extent_io.c
index b05d35a7c0f1..8d6f55fbd28e 100644
--- a/trunk/fs/btrfs/extent_io.c
+++ b/trunk/fs/btrfs/extent_io.c
@@ -3308,7 +3308,7 @@ int try_release_extent_mapping(struct extent_map_tree *map,
 			len = end - start + 1;
 			write_lock(&map->lock);
 			em = lookup_extent_mapping(map, start, len);
-			if (IS_ERR_OR_NULL(em)) {
+			if (!em) {
 				write_unlock(&map->lock);
 				break;
 			}
diff --git a/trunk/fs/btrfs/volumes.c b/trunk/fs/btrfs/volumes.c
index d8f282b5baa9..cd040bf3fd87 100644
--- a/trunk/fs/btrfs/volumes.c
+++ b/trunk/fs/btrfs/volumes.c
@@ -1954,7 +1954,7 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
 	read_unlock(&em_tree->lock);
 
-	BUG_ON(em->start > chunk_offset ||
+	BUG_ON(!em || em->start > chunk_offset ||
 	       em->start + em->len < chunk_offset);
 	map = (struct map_lookup *)em->bdev;