Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
 "Zygo tracked down a very old bug with inline compressed extents.

  I didn't tag this one for stable because I want to do individual
  tested backports. It's a little tricky and I'd rather do some extra
  testing on it along the way"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: add missing memset while reading compressed inline extents
  Btrfs: fix regression in lock_delalloc_pages
  btrfs: remove btrfs_err_str function from uapi/linux/btrfs.h

2 files changed, 16 insertions, 1 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 28e81922a21c..8df797432740 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1714,7 +1714,8 @@ static int __process_pages_contig(struct address_space *mapping,
 			 * can we find nothing at @index.
 			 */
 			ASSERT(page_ops & PAGE_LOCK);
-			return ret;
+			err = -EAGAIN;
+			goto out;
 		}
 
 		for (i = 0; i < ret; i++) {
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c40060cc481f..231503935652 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6709,6 +6709,20 @@ static noinline int uncompress_inline(struct btrfs_path *path,
 	max_size = min_t(unsigned long, PAGE_SIZE, max_size);
 	ret = btrfs_decompress(compress_type, tmp, page,
 			       extent_offset, inline_size, max_size);
+
+	/*
+	 * decompression code contains a memset to fill in any space between the end
+	 * of the uncompressed data and the end of max_size in case the decompressed
+	 * data ends up shorter than ram_bytes.  That doesn't cover the hole between
+	 * the end of an inline extent and the beginning of the next block, so we
+	 * cover that region here.
+	 */
+
+	if (max_size + pg_offset < PAGE_SIZE) {
+		char *map = kmap(page);
+		memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
+		kunmap(page);
+	}
 	kfree(tmp);
 	return ret;
 }