@@ -1275,6 +1275,7 @@ static int cluster_pages_for_defrag(stru
u64 page_end;
u64 page_cnt;
u64 start = (u64)start_index << PAGE_SHIFT;
+ u64 search_start;
int ret;
int i;
int i_done;
@@ -1371,6 +1372,40 @@ again:
lock_extent_bits(&BTRFS_I(inode)->io_tree,
page_start, page_end - 1, &cached_state);
+
+ /*
+ * When defragmenting we skip ranges that have holes or inline extents,
+ * (check should_defrag_range()), to avoid unnecessary IO and wasting
+ * space. At btrfs_defrag_file(), we check if a range should be defragged
+ * before locking the inode and then, if it should, we trigger a sync
+ * page cache readahead - we lock the inode only after that to avoid
+ * blocking for too long other tasks that possibly want to operate on
+ * other file ranges. But before we were able to get the inode lock,
+ * some other task may have punched a hole in the range, or we may have
+ * now an inline extent, in which case we should not defrag. So check
+ * for that here, where we have the inode and the range locked, and bail
+ * out if that happened.
+ */
+ search_start = page_start;
+ while (search_start < page_end) {
+ struct extent_map *em;
+
+ em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, search_start,
+ page_end - search_start);
+ if (IS_ERR(em)) {
+ ret = PTR_ERR(em);
+ goto out_unlock_range;
+ }
+ if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
+ free_extent_map(em);
+ /* Ok, 0 means we did not defrag anything */
+ ret = 0;
+ goto out_unlock_range;
+ }
+ search_start = extent_map_end(em);
+ free_extent_map(em);
+ }
+
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
page_end - 1, EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 0, 0, &cached_state);
@@ -1401,6 +1436,10 @@ again:
btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT);
extent_changeset_free(data_reserved);
return i_done;
+
+out_unlock_range:
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+ page_start, page_end - 1, &cached_state);
out:
for (i = 0; i < i_done; i++) {
unlock_page(pages[i]);