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authorEric Blake <eblake@redhat.com>2017-04-29 14:14:14 -0500
committerMax Reitz <mreitz@redhat.com>2017-05-11 14:28:06 +0200
commite0ef439588ce1ede747f82b77d893190c1cc9f4d (patch)
treedc193838c0b57ccc352e8a3fbd1708cb8775ec15 /block
parent6f3c90af3c50d4f839849c8ba9b6ba4e9a548c28 (diff)
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blkdebug: Sanity check block layer guarantees
Commits 04ed95f4 and 1a62d0ac updated the block layer to auto-fragment any I/O to fit within device boundaries. Additionally, when using a minimum alignment of 4k, we want to ensure the block layer does proper read-modify-write rather than requesting I/O on a slice of a sector. Let's enforce that the contract is obeyed when using blkdebug. For now, blkdebug only allows alignment overrides, and just inherits other limits from whatever device it is wrapping, but a future patch will further enhance things. Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20170429191419.30051-5-eblake@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/blkdebug.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/block/blkdebug.c b/block/blkdebug.c
index 3c08893..a562e2e 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -429,6 +429,13 @@ blkdebug_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule = NULL;
+ /* Sanity check block layer guarantees */
+ assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
+ assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
+ if (bs->bl.max_transfer) {
+ assert(bytes <= bs->bl.max_transfer);
+ }
+
QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
uint64_t inject_offset = rule->options.inject.offset;
@@ -453,6 +460,13 @@ blkdebug_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
BDRVBlkdebugState *s = bs->opaque;
BlkdebugRule *rule = NULL;
+ /* Sanity check block layer guarantees */
+ assert(QEMU_IS_ALIGNED(offset, bs->bl.request_alignment));
+ assert(QEMU_IS_ALIGNED(bytes, bs->bl.request_alignment));
+ if (bs->bl.max_transfer) {
+ assert(bytes <= bs->bl.max_transfer);
+ }
+
QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) {
uint64_t inject_offset = rule->options.inject.offset;