1 files changed, 43 insertions, 8 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d3220d31d3cb..e9df8862012c 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -224,16 +224,19 @@ out:
  * Clear the writeback bits on all of the file
  * pages for a compressed write
  */
-static noinline void end_compressed_writeback(struct inode *inode, u64 start,
-					      unsigned long ram_size)
+static noinline void end_compressed_writeback(struct inode *inode,
+					      const struct compressed_bio *cb)
 {
-	unsigned long index = start >> PAGE_CACHE_SHIFT;
-	unsigned long end_index = (start + ram_size - 1) >> PAGE_CACHE_SHIFT;
+	unsigned long index = cb->start >> PAGE_CACHE_SHIFT;
+	unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_CACHE_SHIFT;
 	struct page *pages[16];
 	unsigned long nr_pages = end_index - index + 1;
 	int i;
 	int ret;
 
+	if (cb->errors)
+		mapping_set_error(inode->i_mapping, -EIO);
+
 	while (nr_pages > 0) {
 		ret = find_get_pages_contig(inode->i_mapping, index,
 				     min_t(unsigned long,
@@ -244,6 +247,8 @@ static noinline void end_compressed_writeback(struct inode *inode, u64 start,
 			continue;
 		}
 		for (i = 0; i < ret; i++) {
+			if (cb->errors)
+				SetPageError(pages[i]);
 			end_page_writeback(pages[i]);
 			page_cache_release(pages[i]);
 		}
@@ -287,10 +292,11 @@ static void end_compressed_bio_write(struct bio *bio, int err)
 	tree->ops->writepage_end_io_hook(cb->compressed_pages[0],
 					 cb->start,
 					 cb->start + cb->len - 1,
-					 NULL, 1);
+					 NULL,
+					 err ? 0 : 1);
 	cb->compressed_pages[0]->mapping = NULL;
 
-	end_compressed_writeback(inode, cb->start, cb->len);
+	end_compressed_writeback(inode, cb);
 	/* note, our inode could be gone now */
 
 	/*
@@ -1011,8 +1017,6 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
 		bytes = min(bytes, working_bytes);
 		kaddr = kmap_atomic(page_out);
 		memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
-		if (*pg_index == (vcnt - 1) && *pg_offset == 0)
-			memset(kaddr + bytes, 0, PAGE_CACHE_SIZE - bytes);
 		kunmap_atomic(kaddr);
 		flush_dcache_page(page_out);
 
@@ -1054,3 +1058,34 @@ int btrfs_decompress_buf2page(char *buf, unsigned long buf_start,
 
 	return 1;
 }
+
+/*
+ * When uncompressing data, we need to make sure and zero any parts of
+ * the biovec that were not filled in by the decompression code.  pg_index
+ * and pg_offset indicate the last page and the last offset of that page
+ * that have been filled in.  This will zero everything remaining in the
+ * biovec.
+ */
+void btrfs_clear_biovec_end(struct bio_vec *bvec, int vcnt,
+				   unsigned long pg_index,
+				   unsigned long pg_offset)
+{
+	while (pg_index < vcnt) {
+		struct page *page = bvec[pg_index].bv_page;
+		unsigned long off = bvec[pg_index].bv_offset;
+		unsigned long len = bvec[pg_index].bv_len;
+
+		if (pg_offset < off)
+			pg_offset = off;
+		if (pg_offset < off + len) {
+			unsigned long bytes = off + len - pg_offset;
+			char *kaddr;
+
+			kaddr = kmap_atomic(page);
+			memset(kaddr + pg_offset, 0, bytes);
+			kunmap_atomic(kaddr);
+		}
+		pg_index++;
+		pg_offset = 0;
+	}
+}