MDEV-13013 InnoDB unnecessarily extends data files

   - While creating a new InnoDB segment, allocates the extent
before allocating the inode or page allocation even though
the pages are present in fragment segment. This patch does
reserve the extent when InnoDB ran out of fragment pages
in the tablespace.

1 files changed, 27 insertions, 11 deletions

diff --git a/storage/innobase/fsp/fsp0fsp.cc b/storage/innobase/fsp/fsp0fsp.cc
index ab143a16417..ba50483cee4 100644
--- a/storage/innobase/fsp/fsp0fsp.cc
+++ b/storage/innobase/fsp/fsp0fsp.cc
@@ -1886,6 +1886,7 @@ fseg_create(fil_space_t *space, ulint byte_offset, mtr_t *mtr,
 	fseg_header_t*	header	= 0; /* remove warning */
 	ulint		n_reserved;
 	ulint		i;
+	bool		reserved_extent = false;
 
 	DBUG_ENTER("fseg_create");
 
@@ -1909,17 +1910,34 @@ fseg_create(fil_space_t *space, ulint byte_offset, mtr_t *mtr,
 		fil_block_check_type(*block, type, mtr);
 	}
 
-	if (!has_done_reservation
-	    && !fsp_reserve_free_extents(&n_reserved, space, 2,
-					 FSP_NORMAL, mtr)) {
-		DBUG_RETURN(NULL);
-	}
-
 	space_header = fsp_get_space_header(space, page_size, mtr);
 
+inode_alloc:
 	inode = fsp_alloc_seg_inode(space, space_header, mtr);
 
 	if (inode == NULL) {
+reserve_extent:
+		if (!has_done_reservation && !reserved_extent) {
+
+			if (!fsp_reserve_free_extents(
+					&n_reserved, space, 2,
+					FSP_NORMAL, mtr)) {
+				DBUG_RETURN(NULL);
+			}
+
+			/* Extents reserved successfully. So
+			try allocating the page or inode */
+			reserved_extent = true;
+			if (inode) {
+				goto page_alloc;
+			}
+
+			goto inode_alloc;
+		}
+
+		if (inode) {
+			fsp_free_seg_inode(space, page_size, inode, mtr);
+		}
 		goto funct_exit;
 	}
 
@@ -1944,6 +1962,7 @@ fseg_create(fil_space_t *space, ulint byte_offset, mtr_t *mtr,
 	}
 
 	if (!block) {
+page_alloc:
 		block = fseg_alloc_free_page_low(space, page_size,
 						 inode, 0, FSP_UP,
 						 mtr, mtr
@@ -1957,10 +1976,7 @@ fseg_create(fil_space_t *space, ulint byte_offset, mtr_t *mtr,
 		ut_ad(!has_done_reservation || block != NULL);
 
 		if (block == NULL) {
-
-			fsp_free_seg_inode(space, page_size, inode, mtr);
-
-			goto funct_exit;
+			goto reserve_extent;
 		}
 
 		ut_ad(rw_lock_get_x_lock_count(&block->lock) == 1);
@@ -1980,7 +1996,7 @@ fseg_create(fil_space_t *space, ulint byte_offset, mtr_t *mtr,
 	mlog_write_ulint(header + FSEG_HDR_SPACE, space->id, MLOG_4BYTES, mtr);
 
 funct_exit:
-	if (!has_done_reservation) {
+	if (!has_done_reservation && reserved_extent) {
 		space->release_free_extents(n_reserved);
 	}