From patchwork Wed Dec 18 13:17:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 11300701 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E75286C1 for ; Wed, 18 Dec 2019 13:19:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BD7A02176D for ; Wed, 18 Dec 2019 13:19:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EW0AQ5C1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD7A02176D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:54294 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ihZEC-0000Ij-Fe for patchwork-qemu-devel@patchwork.kernel.org; Wed, 18 Dec 2019 08:19:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58068) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ihZCT-0006eP-N7 for qemu-devel@nongnu.org; Wed, 18 Dec 2019 08:17:15 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ihZCS-0008SS-3k for qemu-devel@nongnu.org; Wed, 18 Dec 2019 08:17:13 -0500 Received: from mail-wr1-x444.google.com ([2a00:1450:4864:20::444]:42339) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1ihZCR-0008N8-Ov for qemu-devel@nongnu.org; Wed, 18 Dec 2019 08:17:11 -0500 Received: by mail-wr1-x444.google.com with SMTP id q6so2233958wro.9 for ; Wed, 18 Dec 2019 05:17:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=PF8I7FZW+7c2/GhkZAcchyjFmjb92r8OfobN2d5ZEso=; b=EW0AQ5C1YKJ/ezeaRBPj08rHHhXExVrOBK53W7G+XvKb+Bb7XaM3MBxYx+9lkWEFF6 TTs1qzRSyEOr7tIfHghvab6EFkuIIoTBvnlH+t+ofKGRvyqv3b3uWLGwCGbuvGIw2ls2 G3XrUZEPq5SqxNxKWidAdXzmSFlIyI/MPxZkYL1vrueJU+KYkiCZ8YBEFIOGZhJizuT6 VOn2fPxdtYHvMSk95vpw+1T/xmHH+/DDD12TcBBbT83r4Nc1BIZyf8sl+ZJZtJa7d3Dn 7i8ZMVCKK1Cs0MMrc+vtCz944gF+BJjONhh1VBwjIijPrY2HX5wdkQgszcKL90nyTbbk lOzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=PF8I7FZW+7c2/GhkZAcchyjFmjb92r8OfobN2d5ZEso=; b=qL5BSWRfXVcqMvtVY6KjqD+dmVkU3yGaCET5FoqSEyTmjLNKWYtrhBtjyw8R4iVsLl fSnJjtA0uMIdL3bs6ImnYVrRQWlw9UUZXFHJ1i2O5FlufkKJW/X+6efqwvna9VodEKAo QYMVTAMoPa2sOP7BzRyAWnA/iZTBgkI529J12yailR++N2i7XeK8I6QnhzK9UmSDXqUK bGmlwZRZPjKY3FQq5fBFnDpVxOJBfOTJsqD0xmgbPIyv2wJdaMk7FTXCrrc9tgDJKDHY IoZBHoh9e95LeO1J79HcJdPrv0rcMuKtK/fzskr1O9wIXDPa49iLeOfLx6Q18ypYxBsJ 3pRg== X-Gm-Message-State: APjAAAWgAF20XNUqnAcaBmrFPjCLTjyKqJoOO7B5ESMtK1lddKo5I9ss VQfLZRB2KYYJ7LM3ZplW6Jel10fh X-Google-Smtp-Source: APXvYqy2T5dzAYCmYEame9xa2bfhwxWRXiIvme4LVmKUsAF4yNyt2hVSw5kVjAdi8+l9aRD/AwOtPg== X-Received: by 2002:a5d:538e:: with SMTP id d14mr2912584wrv.358.1576675030489; Wed, 18 Dec 2019 05:17:10 -0800 (PST) Received: from 640k.lan ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id t1sm2447980wma.43.2019.12.18.05.17.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Dec 2019 05:17:10 -0800 (PST) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PATCH 2/3] block/io: wait for serialising requests when a request becomes serialising Date: Wed, 18 Dec 2019 14:17:05 +0100 Message-Id: <1576675026-25046-3-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1576675026-25046-1-git-send-email-pbonzini@redhat.com> References: <1576675026-25046-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4864:20::444 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Peter Lieven , qemu-block@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Marking without waiting would not result in actual serialising behavior. Thus, make a call bdrv_mark_request_serialising sufficient for serialisation to happen. Signed-off-by: Paolo Bonzini --- block/file-posix.c | 1 - block/io.c | 39 ++++++++++++++++----------------------- include/block/block_int.h | 3 +-- 3 files changed, 17 insertions(+), 26 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index 1b805bd..2b08b02 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2753,7 +2753,6 @@ raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, req->overlap_bytes = req->bytes; bdrv_mark_request_serialising(req, bs->bl.request_alignment); - bdrv_wait_serialising_requests(req); } #endif diff --git a/block/io.c b/block/io.c index b3a67fe..e844c4b 100644 --- a/block/io.c +++ b/block/io.c @@ -41,6 +41,7 @@ #define MAX_BOUNCE_BUFFER (32768 << BDRV_SECTOR_BITS) static void bdrv_parent_cb_resize(BlockDriverState *bs); +static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self); static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes, BdrvRequestFlags flags); @@ -715,7 +716,7 @@ static void tracked_request_begin(BdrvTrackedRequest *req, qemu_co_mutex_unlock(&bs->reqs_lock); } -void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) +bool bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) { int64_t overlap_offset = req->offset & ~(align - 1); uint64_t overlap_bytes = ROUND_UP(req->offset + req->bytes, align) @@ -728,18 +729,7 @@ void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) req->overlap_offset = MIN(req->overlap_offset, overlap_offset); req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); -} - -static bool is_request_serialising_and_aligned(BdrvTrackedRequest *req) -{ - /* - * If the request is serialising, overlap_offset and overlap_bytes are set, - * so we can check if the request is aligned. Otherwise, don't care and - * return false. - */ - - return req->serialising && (req->offset == req->overlap_offset) && - (req->bytes == req->overlap_bytes); + return bdrv_wait_serialising_requests(req); } /** @@ -823,7 +813,7 @@ void bdrv_dec_in_flight(BlockDriverState *bs) bdrv_wakeup(bs); } -bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self) +static bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self) { BlockDriverState *bs = self->bs; BdrvTrackedRequest *req; @@ -1455,10 +1445,10 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild *child, * it ensures that the CoR read and write operations are atomic and * guest writes cannot interleave between them. */ bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + } else { + bdrv_wait_serialising_requests(req); } - bdrv_wait_serialising_requests(req); - if (flags & BDRV_REQ_COPY_ON_READ) { int64_t pnum; @@ -1851,13 +1841,18 @@ bdrv_co_write_req_prepare(BdrvChild *child, int64_t offset, uint64_t bytes, assert(!(flags & ~BDRV_REQ_MASK)); if (flags & BDRV_REQ_SERIALISING) { - bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + waited = bdrv_mark_request_serialising(req, bdrv_get_cluster_size(bs)); + /* + * For a misaligned request, we should have already waited + * in bdrv_padding_rmw_read and locked out concurrent writers. + */ + assert(!waited || + (req->offset == req->overlap_offset && + req->bytes == req->overlap_bytes)); + } else { + bdrv_wait_serialising_requests(req); } - waited = bdrv_wait_serialising_requests(req); - - assert(!waited || !req->serialising || - is_request_serialising_and_aligned(req)); assert(req->overlap_offset <= offset); assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); assert(end_sector <= bs->total_sectors || child->perm & BLK_PERM_RESIZE); @@ -2019,7 +2014,6 @@ static int coroutine_fn bdrv_co_do_zero_pwritev(BdrvChild *child, padding = bdrv_init_padding(bs, offset, bytes, &pad); if (padding) { bdrv_mark_request_serialising(req, align); - bdrv_wait_serialising_requests(req); bdrv_padding_rmw_read(child, req, &pad, true); @@ -2122,7 +2116,6 @@ int coroutine_fn bdrv_co_pwritev_part(BdrvChild *child, if (bdrv_pad_request(bs, &qiov, &qiov_offset, &offset, &bytes, &pad)) { bdrv_mark_request_serialising(&req, align); - bdrv_wait_serialising_requests(&req); bdrv_padding_rmw_read(child, &req, &pad, false); } diff --git a/include/block/block_int.h b/include/block/block_int.h index dd033d0..640fb82 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -999,8 +999,7 @@ extern unsigned int bdrv_drain_all_count; void bdrv_apply_subtree_drain(BdrvChild *child, BlockDriverState *new_parent); void bdrv_unapply_subtree_drain(BdrvChild *child, BlockDriverState *old_parent); -bool coroutine_fn bdrv_wait_serialising_requests(BdrvTrackedRequest *self); -void bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); +bool coroutine_fn bdrv_mark_request_serialising(BdrvTrackedRequest *req, uint64_t align); BdrvTrackedRequest *coroutine_fn bdrv_co_get_self_request(BlockDriverState *bs); int get_tmp_filename(char *filename, int size);