Follow-up fix to MDEV-12026: FIL_SPACE_FLAGS trump fil_space_t::flags

Whenever we are reading the first page of a data file, we may have to
adjust the provisionally created fil_space_t::flags to match what is
actually inside the data files. In this way, we will never accidentally
change the format of a data file.

fil_node_t::read_page0(): After validating the FIL_SPACE_FLAGS,
always assign them to space->flags.

btr_root_adjust_on_import(), Datafile::validate_to_dd(),
fil_space_for_table_exists_in_mem(): Adapt to the fix
in fil_node_t::read_page0().

fsp_flags_try_adjust(): Skip the adjustment if full_crc32 is being
used. This adjustment was introduced in MDEV-11623 for upgrading
from MariaDB 10.1.0 to 10.1.20, which used an accidentally changed
format of FIL_SPACE_FLAGS. MariaDB before 10.4.3 never set the
flag that now indicates the full_crc32 format.

storage/innobase/btr/btr0btr.cc

@@ -392,9 +392,21 @@ btr_root_adjust_on_import(
 		} else {
 			/* Check that the table flags and the tablespace
 			flags match. */
-			err = (dict_tf_to_fsp_flags(table->flags)
-			       == table->space->flags)
-				? DB_SUCCESS : DB_CORRUPTION;
+			ulint tf = dict_tf_to_fsp_flags(table->flags);
+			ulint sf = table->space->flags;
+			sf &= ~FSP_FLAGS_MEM_MASK;
+			tf &= ~FSP_FLAGS_MEM_MASK;
+			if (fil_space_t::is_flags_equal(tf, sf)
+			    || fil_space_t::is_flags_equal(sf, tf)) {
+				mutex_enter(&fil_system.mutex);
+				table->space->flags = (table->space->flags
+						       & ~FSP_FLAGS_MEM_MASK)
+					| (tf & FSP_FLAGS_MEM_MASK);
+				mutex_exit(&fil_system.mutex);
+				err = DB_SUCCESS;
+			} else {
+				err = DB_CORRUPTION;
+			}
 		}
 	} else {
 		err = DB_SUCCESS;

storage/innobase/fil/fil0fil.cc

@@ -507,8 +507,8 @@ bool fil_node_t::read_page0(bool first)
 					    + page);
 	if (!fil_space_t::is_valid_flags(flags, space->id)) {
 		ulint cflags = fsp_flags_convert_from_101(flags);
-		if (cflags == ULINT_UNDEFINED
-		    || (cflags ^ space->flags) & ~FSP_FLAGS_MEM_MASK) {
+		if (cflags == ULINT_UNDEFINED) {
+invalid:
 			ib::error()
 				<< "Expected tablespace flags "
 				<< ib::hex(space->flags)
@@ -518,9 +518,19 @@ bool fil_node_t::read_page0(bool first)
 			return false;
 		}
 
+		ulint cf = cflags & ~FSP_FLAGS_MEM_MASK;
+		ulint sf = space->flags & ~FSP_FLAGS_MEM_MASK;
+
+		if (!fil_space_t::is_flags_equal(cf, sf)
+		    && !fil_space_t::is_flags_equal(sf, cf)) {
+			goto invalid;
+		}
+
 		flags = cflags;
 	}
 
+	ut_ad(!(flags & FSP_FLAGS_MEM_MASK));
+
 	/* Try to read crypt_data from page 0 if it is not yet read. */
 	if (!space->crypt_data) {
 		space->crypt_data = fil_space_read_crypt_data(
@@ -552,10 +562,7 @@ bool fil_node_t::read_page0(bool first)
 			size_bytes &= ~os_offset_t(mask);
 		}
 
-		if (space->flags != flags
-		    && fil_space_t::is_flags_equal(flags, space->flags)) {
-			space->flags = flags;
-		}
+		space->flags = (space->flags & FSP_FLAGS_MEM_MASK) | flags;
 
 		this->size = ulint(size_bytes / psize);
 		space->size += this->size;
@@ -3887,7 +3894,7 @@ void fsp_flags_try_adjust(fil_space_t* space, ulint flags)
 {
 	ut_ad(!srv_read_only_mode);
 	ut_ad(fil_space_t::is_valid_flags(flags, space->id));
-	if (space->full_crc32()) {
+	if (space->full_crc32() || fil_space_t::full_crc32(flags)) {
 		return;
 	}
 	if (!space->size && (space->purpose != FIL_TYPE_TABLESPACE
@@ -3947,7 +3954,11 @@ fil_space_for_table_exists_in_mem(
 
 	mutex_enter(&fil_system.mutex);
 	if (fil_space_t* space = fil_space_get_by_id(id)) {
-		if ((space->flags ^ expected_flags) & ~FSP_FLAGS_MEM_MASK) {
+		ulint tf = expected_flags & ~FSP_FLAGS_MEM_MASK;
+		ulint sf = space->flags & ~FSP_FLAGS_MEM_MASK;
+
+		if (!fil_space_t::is_flags_equal(tf, sf)
+		    && !fil_space_t::is_flags_equal(sf, tf)) {
 			goto func_exit;
 		}
 
@@ -3963,7 +3974,8 @@ fil_space_for_table_exists_in_mem(
 
 		/* Adjust the flags that are in FSP_FLAGS_MEM_MASK.
 		FSP_SPACE_FLAGS will not be written back here. */
-		space->flags = expected_flags;
+		space->flags = (space->flags & ~FSP_FLAGS_MEM_MASK)
+			| (expected_flags & FSP_FLAGS_MEM_MASK);
 		mutex_exit(&fil_system.mutex);
 		if (!srv_read_only_mode) {
 			fsp_flags_try_adjust(space, expected_flags

storage/innobase/fsp/fsp0file.cc

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2013, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2018, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -409,7 +409,8 @@ Datafile::validate_to_dd(ulint space_id, ulint flags)
 	If the datafile is a file-per-table tablespace then also match
 	the row format and zip page size. */
 	if (m_space_id == space_id
-	    && fil_space_t::is_flags_equal(m_flags, flags)) {
+	    && (fil_space_t::is_flags_equal(flags, m_flags)
+		|| fil_space_t::is_flags_equal(m_flags, flags))) {
 		/* Datafile matches the tablespace expected. */
 		return(DB_SUCCESS);
 	}