------------------------------------------------------------
revno: 8777
committer: Laurynas Biveinis <laurynas.biveinis@percona.com>
branch nick: mysql-5.7-percona-patches
timestamp: Thu 2014-11-06 20:59:50 +0200
message:
  Fix http://bugs.mysql.com/bug.php?id=68970 (fsp_reserve_free_extents
  switches from small to big tblspace handling too early) by:
  
  - adjusting fsp_reserve_free_extents to actually do the documented
    logic of using special rules for small single-table tablespaces for
    the ones smaller than FSP_EXTENT_SIZE pages rather than
    FSP_EXTENT_SIZE / 2 pages. This applies for non-BLOB reservation
    type, which is not subject to special small tablespace handling.
  - in the same function, set the number of available free extents
    n_free_up to zero instead of overwrapped large numbers if allocating
    for BLOBs.
  - tweak assertion in fsp_reserve_free_pages for the new cutoff value.
  - add assert to fsp_get_available_space_in_free_extents that we don't
    end up with overwrapped free extent value.
  - re-record innodb_zip.innodb_wl6347_comp_indx_stat as with the above
    changes the tablespace file ends up being one page larger at the
    check time.
diff:
=== modified file 'mysql-test/suite/innodb_zip/r/innodb_wl6347_comp_indx_stat.result'
--- mysql-test/suite/innodb_zip/r/innodb_wl6347_comp_indx_stat.result	2014-08-29 08:20:34 +0000
+++ mysql-test/suite/innodb_zip/r/innodb_wl6347_comp_indx_stat.result	2014-11-06 18:59:50 +0000
@@ -981,7 +981,7 @@
 AND table_name='tab5' AND database_name='test'
 AND index_name like 'idx%' ;
 compress_stat	1
-The size of the tab5.ibd file: 159744
+The size of the tab5.ibd file: 163840
 # fetch the compressed page and check the stats
 ===============
 Fetch Records
@@ -1007,7 +1007,7 @@
 AND table_name='tab5' AND database_name='test'
 AND index_name like 'idx%' ;
 compress_stat	1
-The size of the tab5.ibd file: 159744
+The size of the tab5.ibd file: 163840
 # fetch the compressed same page once again and check the stats
 # the stat figures should be same as above query
 ===============
@@ -1034,7 +1034,7 @@
 AND table_name='tab5' AND database_name='test'
 AND index_name like 'idx%' ;
 compress_stat	1
-The size of the tab5.ibd file: 159744
+The size of the tab5.ibd file: 163840
 DROP TABLE tab5;
 #reset the stat table before starting next testcase
 SET GLOBAL innodb_cmp_per_index_enabled=0;

=== modified file 'storage/innobase/fsp/fsp0fsp.cc'
--- storage/innobase/fsp/fsp0fsp.cc	2014-08-29 09:18:37 +0000
+++ storage/innobase/fsp/fsp0fsp.cc	2014-11-06 18:59:50 +0000
@@ -2868,7 +2868,7 @@
 	ulint	n_used;
 
 	ut_a(!is_system_tablespace(space));
-	ut_a(size < FSP_EXTENT_SIZE / 2);
+	ut_a(size < FSP_EXTENT_SIZE);
 
 	descr = xdes_get_descriptor_with_space_hdr(space_header, space, 0,
 						   mtr);
@@ -2949,7 +2949,7 @@
 try_again:
 	size = mtr_read_ulint(space_header + FSP_SIZE, MLOG_4BYTES, mtr);
 
-	if (alloc_type != FSP_BLOB && size < FSP_EXTENT_SIZE / 2) {
+	if (alloc_type != FSP_BLOB && size < FSP_EXTENT_SIZE) {
 		/* Use different rules for small single-table tablespaces */
 		*n_reserved = 0;
 		return(fsp_reserve_free_pages(space, space_header, size, mtr));
@@ -2964,7 +2964,12 @@
 	some of them will contain extent descriptor pages, and therefore
 	will not be free extents */
 
-	n_free_up = (size - free_limit) / FSP_EXTENT_SIZE;
+	if (size >= free_limit) {
+		n_free_up = (size - free_limit) / FSP_EXTENT_SIZE;
+	} else {
+		ut_ad(alloc_type == FSP_BLOB);
+		n_free_up = 0;
+	}
 
 	if (n_free_up > 0) {
 		n_free_up--;
@@ -3122,6 +3127,7 @@
 	some of them will contain extent descriptor pages, and therefore
 	will not be free extents */
 
+	ut_ad(size >= free_limit);
 	n_free_up = (size - free_limit) / FSP_EXTENT_SIZE;
 
 	if (n_free_up > 0) {