From e0ef439588ce1ede747f82b77d893190c1cc9f4d Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Sat, 29 Apr 2017 14:14:14 -0500 Subject: [PATCH] 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 Reviewed-by: Kevin Wolf Reviewed-by: Max Reitz Message-id: 20170429191419.30051-5-eblake@redhat.com Signed-off-by: Max Reitz --- block/blkdebug.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/block/blkdebug.c b/block/blkdebug.c index 3c088934db..a562e2e32f 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;