Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: fix balancing oops when invalidate_inode_pages2 returns EBUSY
  Btrfs: correct error-handling zlib error handling
  Btrfs: remove superfluous NULL pointer check in btrfs_rename()
  Btrfs: make sure the async caching thread advances the key
  Btrfs: fix btrfs_remove_from_free_space corner case

fs/btrfs/extent-tree.c

@@ -265,10 +265,6 @@ static int caching_kthread(void *data)
 
 	atomic_inc(&block_group->space_info->caching_threads);
 	last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
-again:
-	/* need to make sure the commit_root doesn't disappear */
-	down_read(&fs_info->extent_commit_sem);
-
 	/*
 	 * We don't want to deadlock with somebody trying to allocate a new
 	 * extent for the extent root while also trying to search the extent
@@ -282,6 +278,10 @@ static int caching_kthread(void *data)
 	key.objectid = last;
 	key.offset = 0;
 	btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
+again:
+	/* need to make sure the commit_root doesn't disappear */
+	down_read(&fs_info->extent_commit_sem);
+
 	ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
 	if (ret < 0)
 		goto err;
@@ -304,6 +304,19 @@ static int caching_kthread(void *data)
 
 			if (need_resched() ||
 			    btrfs_transaction_in_commit(fs_info)) {
+				leaf = path->nodes[0];
+
+				/* this shouldn't happen, but if the
+				 * leaf is empty just move on.
+				 */
+				if (btrfs_header_nritems(leaf) == 0)
+					break;
+				/*
+				 * we need to copy the key out so that
+				 * we are sure the next search advances
+				 * us forward in the btree.
+				 */
+				btrfs_item_key_to_cpu(leaf, &key, 0);
 				btrfs_release_path(fs_info->extent_root, path);
 				up_read(&fs_info->extent_commit_sem);
 				schedule_timeout(1);

fs/btrfs/free-space-cache.c

@@ -414,11 +414,29 @@ static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_gro
 			      u64 *offset, u64 *bytes)
 {
 	u64 end;
+	u64 search_start, search_bytes;
+	int ret;
 
 again:
 	end = bitmap_info->offset +
 		(u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1;
 
+	/*
+	 * XXX - this can go away after a few releases.
+	 *
+	 * since the only user of btrfs_remove_free_space is the tree logging
+	 * stuff, and the only way to test that is under crash conditions, we
+	 * want to have this debug stuff here just in case somethings not
+	 * working.  Search the bitmap for the space we are trying to use to
+	 * make sure its actually there.  If its not there then we need to stop
+	 * because something has gone wrong.
+	 */
+	search_start = *offset;
+	search_bytes = *bytes;
+	ret = search_bitmap(block_group, bitmap_info, &search_start,
+			    &search_bytes);
+	BUG_ON(ret < 0 || search_start != *offset);
+
 	if (*offset > bitmap_info->offset && *offset + *bytes > end) {
 		bitmap_clear_bits(block_group, bitmap_info, *offset,
 				  end - *offset + 1);
@@ -430,6 +448,7 @@ static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_gro
 	}
 
 	if (*bytes) {
+		struct rb_node *next = rb_next(&bitmap_info->offset_index);
 		if (!bitmap_info->bytes) {
 			unlink_free_space(block_group, bitmap_info);
 			kfree(bitmap_info->bitmap);
@@ -438,16 +457,36 @@ static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_gro
 			recalculate_thresholds(block_group);
 		}
 
-		bitmap_info = tree_search_offset(block_group,
-						 offset_to_bitmap(block_group,
-								  *offset),
-						 1, 0);
-		if (!bitmap_info)
+		/*
+		 * no entry after this bitmap, but we still have bytes to
+		 * remove, so something has gone wrong.
+		 */
+		if (!next)
 			return -EINVAL;
 
+		bitmap_info = rb_entry(next, struct btrfs_free_space,
+				       offset_index);
+
+		/*
+		 * if the next entry isn't a bitmap we need to return to let the
+		 * extent stuff do its work.
+		 */
 		if (!bitmap_info->bitmap)
 			return -EAGAIN;
 
+		/*
+		 * Ok the next item is a bitmap, but it may not actually hold
+		 * the information for the rest of this free space stuff, so
+		 * look for it, and if we don't find it return so we can try
+		 * everything over again.
+		 */
+		search_start = *offset;
+		search_bytes = *bytes;
+		ret = search_bitmap(block_group, bitmap_info, &search_start,
+				    &search_bytes);
+		if (ret < 0 || search_start != *offset)
+			return -EAGAIN;
+
 		goto again;
 	} else if (!bitmap_info->bytes) {
 		unlink_free_space(block_group, bitmap_info);
@@ -644,8 +683,17 @@ int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
 again:
 	info = tree_search_offset(block_group, offset, 0, 0);
 	if (!info) {
-		WARN_ON(1);
-		goto out_lock;
+		/*
+		 * oops didn't find an extent that matched the space we wanted
+		 * to remove, look for a bitmap instead
+		 */
+		info = tree_search_offset(block_group,
+					  offset_to_bitmap(block_group, offset),
+					  1, 0);
+		if (!info) {
+			WARN_ON(1);
+			goto out_lock;
+		}
 	}
 
 	if (info->bytes < bytes && rb_next(&info->offset_index)) {
@@ -957,8 +1005,15 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
 	if (cluster->block_group != block_group)
 		goto out;
 
-	entry = tree_search_offset(block_group, search_start, 0, 0);
-
+	/*
+	 * search_start is the beginning of the bitmap, but at some point it may
+	 * be a good idea to point to the actual start of the free area in the
+	 * bitmap, so do the offset_to_bitmap trick anyway, and set bitmap_only
+	 * to 1 to make sure we get the bitmap entry
+	 */
+	entry = tree_search_offset(block_group,
+				   offset_to_bitmap(block_group, search_start),
+				   1, 0);
 	if (!entry || !entry->bitmap)
 		goto out;
 

fs/btrfs/inode.c

@@ -4785,8 +4785,7 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	 * and the replacement file is large.  Start IO on it now so
 	 * we don't add too much work to the end of the transaction
 	 */
-	if (new_inode && old_inode && S_ISREG(old_inode->i_mode) &&
-	    new_inode->i_size &&
+	if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
 	    old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
 		filemap_flush(old_inode->i_mapping);
 

fs/btrfs/relocation.c

@@ -2553,8 +2553,13 @@ int relocate_inode_pages(struct inode *inode, u64 start, u64 len)
 	last_index = (start + len - 1) >> PAGE_CACHE_SHIFT;
 
 	/* make sure the dirty trick played by the caller work */
-	ret = invalidate_inode_pages2_range(inode->i_mapping,
-					    first_index, last_index);
+	while (1) {
+		ret = invalidate_inode_pages2_range(inode->i_mapping,
+						    first_index, last_index);
+		if (ret != -EBUSY)
+			break;
+		schedule_timeout(HZ/10);
+	}
 	if (ret)
 		goto out_unlock;
 

fs/btrfs/zlib.c

@@ -208,7 +208,7 @@ int btrfs_zlib_compress_pages(struct address_space *mapping,
 	*total_in = 0;
 
 	workspace = find_zlib_workspace();
-	if (!workspace)
+	if (IS_ERR(workspace))
 		return -1;
 
 	if (Z_OK != zlib_deflateInit(&workspace->def_strm, 3)) {
@@ -366,7 +366,7 @@ int btrfs_zlib_decompress_biovec(struct page **pages_in,
 	char *kaddr;
 
 	workspace = find_zlib_workspace();
-	if (!workspace)
+	if (IS_ERR(workspace))
 		return -ENOMEM;
 
 	data_in = kmap(pages_in[page_in_index]);
@@ -547,7 +547,7 @@ int btrfs_zlib_decompress(unsigned char *data_in,
 		return -ENOMEM;
 
 	workspace = find_zlib_workspace();
-	if (!workspace)
+	if (IS_ERR(workspace))
 		return -ENOMEM;
 
 	workspace->inf_strm.next_in = data_in;