From patchwork Tue Aug 21 00:58:42 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fam Zheng X-Patchwork-Id: 10570903 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D1B4814E1 for ; Tue, 21 Aug 2018 01:09:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C0F0229E87 for ; Tue, 21 Aug 2018 01:09:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B532B29E8C; Tue, 21 Aug 2018 01:09:24 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 47BE629E87 for ; Tue, 21 Aug 2018 01:09:23 +0000 (UTC) Received: from localhost ([::1]:50128 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frvAg-0004Dh-L0 for patchwork-qemu-devel@patchwork.kernel.org; Mon, 20 Aug 2018 21:09:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34243) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frv76-0001Ln-BR for qemu-devel@nongnu.org; Mon, 20 Aug 2018 21:05:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1frv0e-0000vC-M2 for qemu-devel@nongnu.org; Mon, 20 Aug 2018 20:59:02 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57688 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1frv0c-0000tI-RS; Mon, 20 Aug 2018 20:58:58 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 83DDB83221; Tue, 21 Aug 2018 00:58:58 +0000 (UTC) Received: from lemon.usersys.redhat.com (ovpn-12-57.pek2.redhat.com [10.72.12.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 60A2A7C52; Tue, 21 Aug 2018 00:58:56 +0000 (UTC) From: Fam Zheng To: qemu-devel@nongnu.org Date: Tue, 21 Aug 2018 08:58:42 +0800 Message-Id: <20180821005843.5146-3-famz@redhat.com> In-Reply-To: <20180821005843.5146-1-famz@redhat.com> References: <20180821005843.5146-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 21 Aug 2018 00:58:58 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Tue, 21 Aug 2018 00:58:58 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'famz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v4 2/3] file-posix: Drop s->lock_fd X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The lock_fd field is not strictly necessary because transferring locked bytes from old fd to the new one shouldn't fail anyway. This spares the user one fd per image. Signed-off-by: Fam Zheng Reviewed-by: Max Reitz --- block/file-posix.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index f062e477e9..26d4e487d2 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -142,7 +142,6 @@ do { \ typedef struct BDRVRawState { int fd; - int lock_fd; bool use_lock; int type; int open_flags; @@ -153,7 +152,7 @@ typedef struct BDRVRawState { uint64_t shared_perm; /* The perms bits whose corresponding bytes are already locked in - * s->lock_fd. */ + * s->fd. */ uint64_t locked_perm; uint64_t locked_shared_perm; @@ -542,18 +541,6 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, } s->fd = fd; - s->lock_fd = -1; - if (s->use_lock) { - fd = qemu_open(filename, s->open_flags); - if (fd < 0) { - ret = -errno; - error_setg_errno(errp, errno, "Could not open '%s' for locking", - filename); - qemu_close(s->fd); - goto fail; - } - s->lock_fd = fd; - } s->perm = 0; s->shared_perm = BLK_PERM_ALL; @@ -818,15 +805,13 @@ static int raw_handle_perm_lock(BlockDriverState *bs, return 0; } - assert(s->lock_fd > 0); - switch (op) { case RAW_PL_PREPARE: - ret = raw_apply_lock_bytes(s, s->lock_fd, s->perm | new_perm, + ret = raw_apply_lock_bytes(s, s->fd, s->perm | new_perm, ~s->shared_perm | ~new_shared, false, errp); if (!ret) { - ret = raw_check_lock_bytes(s->lock_fd, new_perm, new_shared, errp); + ret = raw_check_lock_bytes(s->fd, new_perm, new_shared, errp); if (!ret) { return 0; } @@ -834,7 +819,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs, op = RAW_PL_ABORT; /* fall through to unlock bytes. */ case RAW_PL_ABORT: - raw_apply_lock_bytes(s, s->lock_fd, s->perm, ~s->shared_perm, + raw_apply_lock_bytes(s, s->fd, s->perm, ~s->shared_perm, true, &local_err); if (local_err) { /* Theoretically the above call only unlocks bytes and it cannot @@ -844,7 +829,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs, } break; case RAW_PL_COMMIT: - raw_apply_lock_bytes(s, s->lock_fd, new_perm, ~new_shared, + raw_apply_lock_bytes(s, s->fd, new_perm, ~new_shared, true, &local_err); if (local_err) { /* Theoretically the above call only unlocks bytes and it cannot @@ -956,10 +941,18 @@ static void raw_reopen_commit(BDRVReopenState *state) { BDRVRawReopenState *rs = state->opaque; BDRVRawState *s = state->bs->opaque; + Error *local_err = NULL; s->check_cache_dropped = rs->check_cache_dropped; s->open_flags = rs->open_flags; + /* Copy locks to the new fd before closing the old one. */ + raw_apply_lock_bytes(NULL, rs->fd, s->locked_perm, + ~s->locked_shared_perm, false, &local_err); + if (local_err) { + /* shouldn't fail in a sane host, but report it just in case. */ + error_report_err(local_err); + } qemu_close(s->fd); s->fd = rs->fd; @@ -1952,10 +1945,6 @@ static void raw_close(BlockDriverState *bs) qemu_close(s->fd); s->fd = -1; } - if (s->lock_fd >= 0) { - qemu_close(s->lock_fd); - s->lock_fd = -1; - } } /**