Attachment 227833 Details for Bug 257958 – patch for MariaDB 10.3 and 10.4

[patch] patch for MariaDB 10.3 and 10.4

patch-MDEV-26537 (text/plain), 5.19 KB, created by Bernard Spil on 2021-09-11 12:53:43 UTC

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Creator: Bernard Spil

Created: 2021-09-11 12:53:43 UTC

Size: 5.19 KB

patch

obsolete

>From d09426f9e60fd93296464ec9eb5f9d85566437d3 Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Marko=20M=C3=A4kel=C3=A4?= <marko.makela@mariadb.com>
>Date: Fri, 10 Sep 2021 19:15:41 +0300
>Subject: [PATCH] MDEV-26537 InnoDB corrupts files due to incorrect st_blksize
> calculation
>
>The st_blksize returned by fstat(2) is not documented to be
>a power of 2, like we assumed in
>commit 58252fff15acfe7c7b0452a87e202e3f8e454e19 (MDEV-26040).
>While on Linux, the st_blksize appears to report the file system
>block size (which hopefully is not smaller than the sector size
>of the underlying block device), on FreeBSD we observed
>st_blksize values that might have been something similar to st_size.
>
>Also IBM AIX was affected by this. A simple test case would
>lead to a crash when using the minimum innodb_buffer_pool_size=5m
>on both FreeBSD and AIX:
>
>seq -f 'create table t%g engine=innodb select * from seq_1_to_200000;' \
>1 100|mysql test&
>seq -f 'create table u%g engine=innodb select * from seq_1_to_200000;' \
>1 100|mysql test&
>
>We will fix this by not trusting st_blksize at all, and assuming that
>the smallest allowed write size (for O_DIRECT) is 4096 bytes. We hope
>that no storage systems with larger block size exist. Anything larger
>than 4096 bytes should be unlikely, given that it is the minimum
>virtual memory page size of many contemporary processors.
>
>MariaDB Server on Microsoft Windows was not affected by this.
>
>While the 512-byte sector size of the venerable Seagate ST-225 is still
>in widespread use, the minimum innodb_page_size is 4096 bytes, and
>innodb_log_file_size can be set in integer multiples of 65536 bytes.
>
>The only occasion where InnoDB uses smaller data file block sizes than
>4096 bytes is with ROW_FORMAT=COMPRESSED tables with KEY_BLOCK_SIZE=1
>or KEY_BLOCK_SIZE=2 (or innodb_page_size=4096). For such tables,
>we will from now on preallocate space in integer multiples of 4096 bytes
>and let regular writes extend the file by 1024, 2048, or 3072 bytes.
>
>The view INFORMATION_SCHEMA.INNODB_SYS_TABLESPACES.FS_BLOCK_SIZE
>should report the raw st_blksize.
>
>For page_compressed tables, the function fil_space_get_block_size()
>will map to 512 any st_blksize value that is larger than 4096.
>
>os_file_set_size(): Assume that the file system block size is 4096 bytes,
>and only support extending files to integer multiples of 4096 bytes.
>
>fil_space_extend_must_retry(): Round down the preallocation size to
>an integer multiple of 4096 bytes.
>--- mysql-test/suite/innodb/t/check_ibd_filesize.test.orig	2021-08-02 10:58:56 UTC
>+++ mysql-test/suite/innodb/t/check_ibd_filesize.test
>@@ -46,6 +46,12 @@ perl;
> print "# bytes: ", (-s "$ENV{MYSQLD_DATADIR}/test/t1.ibd"), "\n";
> EOF
> INSERT INTO t1 SELECT seq,REPEAT('a',30000) FROM seq_1_to_20;
>+# Ensure that the file will be extended with the last 1024-byte page
>+# after the file was pre-extended in 4096-byte increments.
>+--disable_query_log
>+FLUSH TABLE t1 FOR EXPORT;
>+UNLOCK TABLES;
>+--enable_query_log
> perl;
> print "# bytes: ", (-s "$ENV{MYSQLD_DATADIR}/test/t1.ibd"), "\n";
> EOF
> mysql-test/suite/innodb/t/check_ibd_filesize.test |  6 ++++++
> storage/innobase/fil/fil0fil.cc                   | 13 +++++++++----
> storage/innobase/os/os0file.cc                    |  7 ++++---
> 3 files changed, 19 insertions(+), 7 deletions(-)
>
>--- storage/innobase/fil/fil0fil.cc.orig	2021-08-02 10:58:57 UTC
>+++ storage/innobase/fil/fil0fil.cc
>@@ -942,11 +942,17 @@ fil_space_extend_must_retry(
> 	const page_size_t	pageSize(space->flags);
> 	const ulint		page_size = pageSize.physical();
> 
>-	/* fil_read_first_page() expects srv_page_size bytes.
>-	fil_node_open_file() expects at least 4 * srv_page_size bytes.*/
>-	os_offset_t new_size = std::max(
>-		os_offset_t(size - file_start_page_no) * page_size,
>+		/* fil_read_first_page() expects innodb_page_size bytes.
>+		fil_node_open_file() expects at least 4 * innodb_page_size bytes.
>+		os_file_set_size() expects multiples of 4096 bytes.
>+		For ROW_FORMAT=COMPRESSED tables using 1024-byte or 2048-byte
>+		pages, we will preallocate up to an integer multiple of 4096 bytes,
>+		and let normal writes append 1024, 2048, or 3072 bytes to the file. */
>+		os_offset_t new_size = std::max(
>+		(os_offset_t(size - file_start_page_no) * page_size)
>+		& ~os_offset_t(4095),
> 		os_offset_t(FIL_IBD_FILE_INITIAL_SIZE << srv_page_size_shift));
>+		
> 
> 	*success = os_file_set_size(node->name, node->handle, new_size,
> 		FSP_FLAGS_HAS_PAGE_COMPRESSION(space->flags));
>--- storage/innobase/os/os0file.cc.orig	2021-08-02 10:58:57 UTC
>+++ storage/innobase/os/os0file.cc
>@@ -5351,6 +5351,8 @@ os_file_set_size(
> 	os_offset_t	size,
> 	bool	is_sparse)
> {
>+	ut_ad(!(size & 4095));
>+
> #ifdef _WIN32
> 	/* On Windows, changing file size works well and as expected for both
> 	sparse and normal files.
>@@ -5392,7 +5394,7 @@ fallback:
> 			if (current_size >= size) {
> 				return true;
> 			}
>-			current_size &= ~os_offset_t(statbuf.st_blksize - 1);
>+			current_size &= ~4095ULL;
> 			err = posix_fallocate(file, current_size,
> 					      size - current_size);
> 		}
>@@ -5432,8 +5434,7 @@ fallback:
> 	if (fstat(file, &statbuf)) {
> 		return false;
> 	}
>-	os_offset_t current_size = statbuf.st_size
>-		& ~os_offset_t(statbuf.st_blksize - 1);
>+	os_offset_t current_size = statbuf.st_size & ~4095ULL;
> #endif
> 	if (current_size >= size) {
> 		return true;

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brnrd: maintainer-approval+

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Attachments on bug 257958: 227335 | 227833