From cb60b78e889e738f88e4c056d7312290869e4f1d Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 20 Aug 2014 16:40:14 +0200 Subject: [PATCH 7/7] mirror: Fix qiov size for short requests Message-id: <1408552814-23031-8-git-send-email-eblake@redhat.com> Patchwork-id: 60650 O-Subject: [qemu-kvm-rhev 7.0.z PATCH 7/7] mirror: Fix qiov size for short requests Bugzilla: 1132806 RH-Acked-by: Paolo Bonzini RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi From: Kevin Wolf When mirroring an image of a size that is not a multiple of the mirror job granularity, the last request would have the right nb_sectors argument, but a qiov that is rounded up to the next multiple of the granularity. Don't do this. This fixes a segfault that is caused by raw-posix being confused by this and allocating a buffer with request length, but operating on it with qiov length. [s/Driver/Drive/ in qemu-iotests 041 as suggested by Eric --Stefan] Reported-by: Eric Blake Signed-off-by: Kevin Wolf Tested-by: Eric Blake Reviewed-by: Eric Blake Signed-off-by: Stefan Hajnoczi (cherry picked from commit 5a0f6fd5c84573387056e0464a7fc0c6fb70b2dc) Conflicts: tests/qemu-iotests/041.out - context with fewer tests run downstream Signed-off-by: Eric Blake Signed-off-by: Miroslav Rezanina --- block/mirror.c | 4 +++- tests/qemu-iotests/041 | 5 +++++ tests/qemu-iotests/041.out | 4 ++-- 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index cdc0268..b7cf4ab 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -243,9 +243,11 @@ static void coroutine_fn mirror_iteration(MirrorBlockJob *s) next_sector = sector_num; while (nb_chunks-- > 0) { MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); + size_t remaining = (nb_sectors * BDRV_SECTOR_SIZE) - op->qiov.size; + QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); s->buf_free_count--; - qemu_iovec_add(&op->qiov, buf, s->granularity); + qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); /* Advance the HBitmapIter in parallel, so that we do not examine * the same sector twice. diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041 index 912e499..b654081 100755 --- a/tests/qemu-iotests/041 +++ b/tests/qemu-iotests/041 @@ -270,6 +270,11 @@ class TestSingleDriveZeroLength(TestSingleDrive): test_small_buffer2 = None test_large_cluster = None +class TestSingleDriveUnalignedLength(TestSingleDrive): + image_len = 1025 * 1024 + test_small_buffer2 = None + test_large_cluster = None + class TestMirrorNoBacking(ImageMirroringTestCase): image_len = 2 * 1024 * 1024 # MB diff --git a/tests/qemu-iotests/041.out b/tests/qemu-iotests/041.out index cfa5c0d..802ffaa 100644 --- a/tests/qemu-iotests/041.out +++ b/tests/qemu-iotests/041.out @@ -1,5 +1,5 @@ -................................... +........................................... ---------------------------------------------------------------------- -Ran 35 tests +Ran 43 tests OK -- 1.7.1