From nobody Thu Apr 18 18:32:24 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1502452010798584.7041765883648; Fri, 11 Aug 2017 04:46:50 -0700 (PDT) Received: from localhost ([::1]:32814 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dg8Ov-0005m9-IY for importer@patchew.org; Fri, 11 Aug 2017 07:46:49 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47945) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dg8NM-0004mu-Oj for qemu-devel@nongnu.org; Fri, 11 Aug 2017 07:45:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dg8NL-0001Lk-DM for qemu-devel@nongnu.org; Fri, 11 Aug 2017 07:45:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49972) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dg8NA-0001EO-RQ; Fri, 11 Aug 2017 07:45:01 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C803D16C37F; Fri, 11 Aug 2017 11:44:59 +0000 (UTC) Received: from lemon.redhat.com (ovpn-12-60.pek2.redhat.com [10.72.12.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6286D60606; Fri, 11 Aug 2017 11:44:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com C803D16C37F Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=famz@redhat.com From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 11 Aug 2017 19:44:46 +0800 Message-Id: <20170811114447.25187-2-famz@redhat.com> In-Reply-To: <20170811114447.25187-1-famz@redhat.com> References: <20170811114447.25187-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 11 Aug 2017 11:44:59 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH for-2.10? v3 1/2] osdep: Add runtime OFD lock detection 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, christian.ehrhardt@canonical.com, Max Reitz , Andrew Baumann , jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Build time check of OFD lock is not sufficient and can cause image open errors when the runtime environment doesn't support it. Add a helper function to probe it at runtime, additionally. Also provide a qemu_has_ofd_lock() for callers to check the status. Signed-off-by: Fam Zheng --- include/qemu/osdep.h | 1 + util/osdep.c | 66 ++++++++++++++++++++++++++++++++++++++++++++----= ---- 2 files changed, 57 insertions(+), 10 deletions(-) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 3b74f6fcb2..6855b94bbf 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -357,6 +357,7 @@ int qemu_dup(int fd); int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); int qemu_unlock_fd(int fd, int64_t start, int64_t len); int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); +bool qemu_has_ofd_lock(void); =20 #if defined(__HAIKU__) && defined(__i386__) #define FMT_pid "%ld" diff --git a/util/osdep.c b/util/osdep.c index a2863c8e53..a479fedc4a 100644 --- a/util/osdep.c +++ b/util/osdep.c @@ -38,14 +38,6 @@ extern int madvise(caddr_t, size_t, int); #include "qemu/error-report.h" #include "monitor/monitor.h" =20 -#ifdef F_OFD_SETLK -#define QEMU_SETLK F_OFD_SETLK -#define QEMU_GETLK F_OFD_GETLK -#else -#define QEMU_SETLK F_SETLK -#define QEMU_GETLK F_GETLK -#endif - static bool fips_enabled =3D false; =20 static const char *hw_version =3D QEMU_HW_VERSION; @@ -82,6 +74,10 @@ int qemu_madvise(void *addr, size_t len, int advice) } =20 #ifndef _WIN32 + +static int fcntl_op_setlk =3D -1; +static int fcntl_op_getlk =3D -1; + /* * Dups an fd and sets the flags */ @@ -149,6 +145,54 @@ static int qemu_parse_fdset(const char *param) return qemu_parse_fd(param); } =20 +static void qemu_probe_lock_ops(void) +{ + if (fcntl_op_setlk =3D=3D -1) { +#ifdef F_OFD_SETLK + int fd; + int ret; + struct flock fl =3D { + .l_whence =3D SEEK_SET, + .l_start =3D 0, + .l_len =3D 0, + .l_type =3D F_WRLCK, + }; + + fd =3D open("/dev/null", O_RDWR); + if (fd < 0) { + fprintf(stderr, + "Failed to open /dev/null for OFD lock probing: %s\n", + strerror(errno)); + fcntl_op_setlk =3D F_SETLK; + fcntl_op_getlk =3D F_GETLK; + return; + } + ret =3D fcntl(fd, F_OFD_GETLK, &fl); + close(fd); + if (!ret) { + fcntl_op_setlk =3D F_OFD_SETLK; + fcntl_op_getlk =3D F_OFD_GETLK; + } else { + fcntl_op_setlk =3D F_SETLK; + fcntl_op_getlk =3D F_GETLK; + } +#else + fcntl_op_setlk =3D F_SETLK; + fcntl_op_getlk =3D F_GETLK; +#endif + } +} + +bool qemu_has_ofd_lock(void) +{ + qemu_probe_lock_ops(); +#ifdef F_OFD_SETLK + return fcntl_op_setlk =3D=3D F_OFD_SETLK; +#else + return false; +#endif +} + static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type) { int ret; @@ -158,7 +202,8 @@ static int qemu_lock_fcntl(int fd, int64_t start, int64= _t len, int fl_type) .l_len =3D len, .l_type =3D fl_type, }; - ret =3D fcntl(fd, QEMU_SETLK, &fl); + qemu_probe_lock_ops(); + ret =3D fcntl(fd, fcntl_op_setlk, &fl); return ret =3D=3D -1 ? -errno : 0; } =20 @@ -181,7 +226,8 @@ int qemu_lock_fd_test(int fd, int64_t start, int64_t le= n, bool exclusive) .l_len =3D len, .l_type =3D exclusive ? F_WRLCK : F_RDLCK, }; - ret =3D fcntl(fd, QEMU_GETLK, &fl); + qemu_probe_lock_ops(); + ret =3D fcntl(fd, fcntl_op_getlk, &fl); if (ret =3D=3D -1) { return -errno; } else { --=20 2.13.4 From nobody Thu Apr 18 18:32:24 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1502452119359644.3082986895723; Fri, 11 Aug 2017 04:48:39 -0700 (PDT) Received: from localhost ([::1]:32941 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dg8Qg-0007AP-7a for importer@patchew.org; Fri, 11 Aug 2017 07:48:38 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47964) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dg8NO-0004ov-FU for qemu-devel@nongnu.org; Fri, 11 Aug 2017 07:45:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dg8NN-0001OM-Aw for qemu-devel@nongnu.org; Fri, 11 Aug 2017 07:45:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57190) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dg8NK-0001Kc-Ha; Fri, 11 Aug 2017 07:45:10 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 79E60C047B7D; Fri, 11 Aug 2017 11:45:09 +0000 (UTC) Received: from lemon.redhat.com (ovpn-12-60.pek2.redhat.com [10.72.12.60]) by smtp.corp.redhat.com (Postfix) with ESMTP id 616FF60606; Fri, 11 Aug 2017 11:45:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 79E60C047B7D Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=famz@redhat.com From: Fam Zheng To: qemu-devel@nongnu.org Date: Fri, 11 Aug 2017 19:44:47 +0800 Message-Id: <20170811114447.25187-3-famz@redhat.com> In-Reply-To: <20170811114447.25187-1-famz@redhat.com> References: <20170811114447.25187-1-famz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Fri, 11 Aug 2017 11:45:09 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH for-2.10? v3 2/2] file-posix: Do runtime check for ofd lock API 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, christian.ehrhardt@canonical.com, Max Reitz , Andrew Baumann , jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" It is reported that on Windows Subsystem for Linux, ofd operations fail with -EINVAL. In other words, QEMU binary built with system headers that exports F_OFD_SETLK doesn't necessarily run in an environment that actually supports it: $ qemu-system-aarch64 ... -drive file=3Dtest.vhdx,if=3Dnone,id=3Dhd0 \ -device virtio-blk-pci,drive=3Dhd0 qemu-system-aarch64: -drive file=3Dtest.vhdx,if=3Dnone,id=3Dhd0: Failed to = unlock byte 100 qemu-system-aarch64: -drive file=3Dtest.vhdx,if=3Dnone,id=3Dhd0: Failed to = unlock byte 100 qemu-system-aarch64: -drive file=3Dtest.vhdx,if=3Dnone,id=3Dhd0: Failed to = lock byte 100 As a matter of fact this is not WSL specific. It can happen when running a QEMU compiled against a newer glibc on an older kernel, such as in a containerized environment. Let's do a runtime check to cope with that. Reported-by: Andrew Baumann Reviewed-by: Eric Blake Signed-off-by: Fam Zheng --- block/file-posix.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/block/file-posix.c b/block/file-posix.c index f4de022ae0..cb3bfce147 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -457,22 +457,19 @@ static int raw_open_common(BlockDriverState *bs, QDic= t *options, switch (locking) { case ON_OFF_AUTO_ON: s->use_lock =3D true; -#ifndef F_OFD_SETLK - fprintf(stderr, - "File lock requested but OFD locking syscall is unavailabl= e, " - "falling back to POSIX file locks.\n" - "Due to the implementation, locks can be lost unexpectedly= .\n"); -#endif + if (!qemu_has_ofd_lock()) { + fprintf(stderr, + "File lock requested but OFD locking syscall is " + "unavailable, falling back to POSIX file locks.\n" + "Due to the implementation, locks can be lost " + "unexpectedly.\n"); + } break; case ON_OFF_AUTO_OFF: s->use_lock =3D false; break; case ON_OFF_AUTO_AUTO: -#ifdef F_OFD_SETLK - s->use_lock =3D true; -#else - s->use_lock =3D false; -#endif + s->use_lock =3D qemu_has_ofd_lock(); break; default: abort(); --=20 2.13.4