49 lines
1.9 KiB
Diff
49 lines
1.9 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
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Date: Thu, 11 Apr 2024 11:29:23 +0200
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Subject: [PATCH] block/copy-before-write: support unligned snapshot-discard
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First thing that crashes on unligned access here is
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bdrv_reset_dirty_bitmap(). Correct way is to align-down the
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snapshot-discard request.
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Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
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Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
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Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
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---
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block/copy-before-write.c | 16 +++++++++++++---
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1 file changed, 13 insertions(+), 3 deletions(-)
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diff --git a/block/copy-before-write.c b/block/copy-before-write.c
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index 5a9456d426..c0e70669a2 100644
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--- a/block/copy-before-write.c
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+++ b/block/copy-before-write.c
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@@ -325,14 +325,24 @@ static int coroutine_fn GRAPH_RDLOCK
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cbw_co_pdiscard_snapshot(BlockDriverState *bs, int64_t offset, int64_t bytes)
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{
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BDRVCopyBeforeWriteState *s = bs->opaque;
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+ uint32_t cluster_size = block_copy_cluster_size(s->bcs);
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+ int64_t aligned_offset = QEMU_ALIGN_UP(offset, cluster_size);
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+ int64_t aligned_end = QEMU_ALIGN_DOWN(offset + bytes, cluster_size);
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+ int64_t aligned_bytes;
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+
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+ if (aligned_end <= aligned_offset) {
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+ return 0;
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+ }
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+ aligned_bytes = aligned_end - aligned_offset;
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WITH_QEMU_LOCK_GUARD(&s->lock) {
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- bdrv_reset_dirty_bitmap(s->access_bitmap, offset, bytes);
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+ bdrv_reset_dirty_bitmap(s->access_bitmap, aligned_offset,
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+ aligned_bytes);
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}
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- block_copy_reset(s->bcs, offset, bytes);
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+ block_copy_reset(s->bcs, aligned_offset, aligned_bytes);
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- return bdrv_co_pdiscard(s->target, offset, bytes);
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+ return bdrv_co_pdiscard(s->target, aligned_offset, aligned_bytes);
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}
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static void GRAPH_RDLOCK cbw_refresh_filename(BlockDriverState *bs)
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