diff options
Diffstat (limited to 'block')
-rw-r--r-- | block/nbd-client.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/block/nbd-client.c b/block/nbd-client.c index 3edb508f66..409c2171bc 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -848,6 +848,25 @@ int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset, if (!bytes) { return 0; } + /* + * Work around the fact that the block layer doesn't do + * byte-accurate sizing yet - if the read exceeds the server's + * advertised size because the block layer rounded size up, then + * truncate the request to the server and tail-pad with zero. + */ + if (offset >= client->info.size) { + assert(bytes < BDRV_SECTOR_SIZE); + qemu_iovec_memset(qiov, 0, 0, bytes); + return 0; + } + if (offset + bytes > client->info.size) { + uint64_t slop = offset + bytes - client->info.size; + + assert(slop < BDRV_SECTOR_SIZE); + qemu_iovec_memset(qiov, bytes - slop, 0, slop); + request.len -= slop; + } + ret = nbd_co_send_request(bs, &request, NULL); if (ret < 0) { return ret; @@ -966,7 +985,8 @@ int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs, .from = offset, .len = MIN(MIN_NON_ZERO(QEMU_ALIGN_DOWN(INT_MAX, bs->bl.request_alignment), - client->info.max_block), bytes), + client->info.max_block), + MIN(bytes, client->info.size - offset)), .flags = NBD_CMD_FLAG_REQ_ONE, }; @@ -977,6 +997,23 @@ int coroutine_fn nbd_client_co_block_status(BlockDriverState *bs, return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; } + /* + * Work around the fact that the block layer doesn't do + * byte-accurate sizing yet - if the status request exceeds the + * server's advertised size because the block layer rounded size + * up, we truncated the request to the server (above), or are + * called on just the hole. + */ + if (offset >= client->info.size) { + *pnum = bytes; + assert(bytes < BDRV_SECTOR_SIZE); + /* Intentionally don't report offset_valid for the hole */ + return BDRV_BLOCK_ZERO; + } + + if (client->info.min_block) { + assert(QEMU_IS_ALIGNED(request.len, client->info.min_block)); + } ret = nbd_co_send_request(bs, &request, NULL); if (ret < 0) { return ret; |