From patchwork Wed Aug 28 18:15:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 13781710 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 301F31A7AFD for ; Wed, 28 Aug 2024 18:14:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724868890; cv=none; b=VJv/8bJX7eFvoswnSfk6yvvxLISy6qB7S234wekavz8hPzxg6Gf2M7nX1gqzAa4TmpfH8tudbQUNwQKPCh0EPNo8wBO5xzkbYYNTDXktZ4JC93vl+4gYEQIK7FVaT9hv+iV+I1KX1ItIL0ix+CHqjYhwnu+8kN/VuId+LDOFfh4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724868890; c=relaxed/simple; bh=nn1Nku1we92KHSuoMPkwcwR4bVw07hvl2MP/SYJ4FgY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=VX8CzpIGCoPVpzj02CNE4ePRyAOUlDHGa/7V1lRi9Dw/JsFQJGsLu2AVvf16V8M70ucDv991m/M7/cTbNx917wMdA0FUinYBnXG4Oxjj/sQtQ2+LGv03NmEkz8xausAX8KgXlU/ZgBfWyJwCbWVZwJbXkKipOzses/fTt020Tz8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=E0xAOeY5; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E0xAOeY5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724868887; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=O0/QF5Ihv3oBscR20RgPJnxLiEgKG1otN46gLtedga0=; b=E0xAOeY5f33JiKLe4RYFaX/9vtOT71aDpKSvvAGzx1Sfu9bqYAIsO2YUw41oKdzgDaSzN3 M2bQ2o6UnTk24Jp9Eji6JMl7saFL81swP+wX0pinRFU3T+bNyI0rNVqc8zvCgg/uYiGBvP VnI3DdSKqLiseL0TwBYnLK9Zz5lBfLw= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-198-iMWsnC-fPxaBcnKhR7ue2w-1; Wed, 28 Aug 2024 14:14:41 -0400 X-MC-Unique: iMWsnC-fPxaBcnKhR7ue2w-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C955D1955D4D; Wed, 28 Aug 2024 18:14:38 +0000 (UTC) Received: from bfoster.redhat.com (unknown [10.22.16.95]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 9322C19560A3; Wed, 28 Aug 2024 18:14:37 +0000 (UTC) From: Brian Foster To: fstests@vger.kernel.org Cc: linux-xfs@vger.kernel.org, djwong@kernel.org, josef@toxicpanda.com, david@fromorbit.com Subject: [PATCH v2 3/4] fsx: support eof page pollution for eof zeroing test coverage Date: Wed, 28 Aug 2024 14:15:33 -0400 Message-ID: <20240828181534.41054-4-bfoster@redhat.com> In-Reply-To: <20240828181534.41054-1-bfoster@redhat.com> References: <20240828181534.41054-1-bfoster@redhat.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 File ranges that are newly exposed via size changing operations are expected to return zeroes until written to. This behavior tends to be difficult to regression test as failures can be racy and transient. fsx is probably the best tool for this type of test coverage, but uncovering issues can require running for a significantly longer period of time than is typically invoked through fstests tests. As a result, these types of regressions tend to go unnoticed for an unfortunate amount of time. To facilitate uncovering these problems more quickly, implement an eof pollution mode in fsx that opportunistically injects post-eof data prior to operations that change file size. Since data injection occurs immediately before the size changing operation, it can be used to detect problems in partial eof page/block zeroing associated with each relevant operation. The implementation takes advantage of the fact that mapped writes can place data beyond eof so long as the page starts within eof. The main reason for the isolated per-operation approach (vs. something like allowing mapped writes to write beyond eof, for example) is to accommodate the fact that writeback zeroes post-eof data on the eof page. The current approach is therefore not necessarily guaranteed to detect all problems, but provides more generic and broad test coverage than the alternative of testing explicit command sequences and doesn't require significant changes to how fsx works. If this proves useful long term, further enhancements can be considered that might facilitate the presence of post-eof data across operations. Enable the feature with the -e command line option. It is disabled by default because zeroing behavior is inconsistent across filesystems. This can also be revisited in the future if zeroing behavior is refined for the major filesystems that rely on fstests for regression testing. Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong --- ltp/fsx.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 77 insertions(+), 2 deletions(-) diff --git a/ltp/fsx.c b/ltp/fsx.c index 4a9be0e1..1ba1bf65 100644 --- a/ltp/fsx.c +++ b/ltp/fsx.c @@ -178,6 +178,7 @@ int dedupe_range_calls = 1; /* -B flag disables */ int copy_range_calls = 1; /* -E flag disables */ int exchange_range_calls = 1; /* -0 flag disables */ int integrity = 0; /* -i flag */ +int pollute_eof = 0; /* -e flag */ int fsxgoodfd = 0; int o_direct; /* -Z */ int aio = 0; @@ -983,6 +984,63 @@ gendata(char *original_buf, char *good_buf, unsigned offset, unsigned size) } } +/* + * Pollute the EOF page with data beyond EOF prior to size change operations. + * This provides additional test coverage for partial EOF block/page zeroing. + * If the upcoming operation does not correctly zero, incorrect file data will + * be detected. + */ +void +pollute_eofpage(unsigned int maxoff) +{ + unsigned offset = file_size; + unsigned pg_offset; + unsigned write_size; + char *p; + + /* + * Nothing to do if pollution disabled or we're simulating. Simulation + * only tracks file size updates and skips syscalls, so we don't want to + * inject file data that won't be zeroed. + */ + if (!pollute_eof || testcalls <= simulatedopcount) + return; + + /* write up to specified max or the end of the eof page */ + pg_offset = offset & mmap_mask; + write_size = MIN(PAGE_SIZE - pg_offset, maxoff - offset); + + if (!pg_offset) + return; + + if (!quiet && + ((progressinterval && testcalls % progressinterval == 0) || + (debug && + (monitorstart == -1 || + (offset + write_size > monitorstart && + (monitorend == -1 || offset <= monitorend)))))) { + prt("%lld pollute_eof\t0x%x thru\t0x%x\t(0x%x bytes)\n", + testcalls, offset, offset + write_size - 1, write_size); + } + + if ((p = (char *)mmap(0, PAGE_SIZE, PROT_READ | PROT_WRITE, + MAP_FILE | MAP_SHARED, fd, + (off_t)(offset - pg_offset))) == MAP_FAILED) { + prterr("pollute_eofpage: mmap"); + return; + } + + /* + * Write to a range just past EOF of the test file. Do not update the + * good buffer because the upcoming operation is expected to zero this + * range of the file. + */ + gendata(original_buf, p, pg_offset, write_size); + + if (munmap(p, PAGE_SIZE) != 0) + prterr("pollute_eofpage: munmap"); +} + /* * Helper to update the tracked file size. If the offset begins beyond current * EOF, zero the range from EOF to offset in the good buffer. @@ -990,8 +1048,10 @@ gendata(char *original_buf, char *good_buf, unsigned offset, unsigned size) void update_file_size(unsigned offset, unsigned size) { - if (offset > file_size) + if (offset > file_size) { + pollute_eofpage(offset + size); memset(good_buf + file_size, '\0', offset - file_size); + } file_size = offset + size; } @@ -1143,6 +1203,9 @@ dotruncate(unsigned size) log4(OP_TRUNCATE, 0, size, FL_NONE); + /* pollute the current EOF before a truncate down */ + if (size < file_size) + pollute_eofpage(maxfilelen); update_file_size(size, 0); if (testcalls <= simulatedopcount) @@ -1305,6 +1368,9 @@ do_collapse_range(unsigned offset, unsigned length) log4(OP_COLLAPSE_RANGE, offset, length, FL_NONE); + /* pollute current eof before collapse truncates down */ + pollute_eofpage(maxfilelen); + if (testcalls <= simulatedopcount) return; @@ -1356,6 +1422,9 @@ do_insert_range(unsigned offset, unsigned length) log4(OP_INSERT_RANGE, offset, length, FL_NONE); + /* pollute current eof before insert truncates up */ + pollute_eofpage(maxfilelen); + if (testcalls <= simulatedopcount) return; @@ -2385,6 +2454,7 @@ usage(void) -b opnum: beginning operation number (default 1)\n\ -c P: 1 in P chance of file close+open at each op (default infinity)\n\ -d: debug output for all operations\n\ + -e: pollute post-eof on size changes (default 0)\n\ -f: flush and invalidate cache after I/O\n\ -g X: write character X instead of random generated data\n\ -i logdev: do integrity testing, logdev is the dm log writes device\n\ @@ -2783,7 +2853,7 @@ main(int argc, char **argv) setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */ while ((ch = getopt_long(argc, argv, - "0b:c:dfg:i:j:kl:m:no:p:qr:s:t:w:xyABD:EFJKHzCILN:OP:RS:UWXZ", + "0b:c:de:fg:i:j:kl:m:no:p:qr:s:t:w:xyABD:EFJKHzCILN:OP:RS:UWXZ", longopts, NULL)) != EOF) switch (ch) { case 'b': @@ -2805,6 +2875,11 @@ main(int argc, char **argv) case 'd': debug = 1; break; + case 'e': + pollute_eof = getnum(optarg, &endp); + if (pollute_eof < 0 || pollute_eof > 1) + usage(); + break; case 'f': flush = 1; break;