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spf=pass smtp.mailfrom=pbonzini@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 6453D34147B From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Thu, 20 Apr 2017 14:00:46 +0200 Message-Id: <20170420120058.28404-6-pbonzini@redhat.com> In-Reply-To: <20170420120058.28404-1-pbonzini@redhat.com> References: <20170420120058.28404-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 20 Apr 2017 12:01:09 +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 05/17] block: access wakeup with atomic ops 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: qemu-block@nongnu.org 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" Signed-off-by: Paolo Bonzini --- block/io.c | 3 ++- block/nfs.c | 4 +++- block/sheepdog.c | 3 ++- include/block/block.h | 5 +++-- include/block/block_int.h | 4 ++-- 5 files changed, 12 insertions(+), 7 deletions(-) diff --git a/block/io.c b/block/io.c index 869322a..3b2ede9 100644 --- a/block/io.c +++ b/block/io.c @@ -501,7 +501,8 @@ static void dummy_bh_cb(void *opaque) =20 void bdrv_wakeup(BlockDriverState *bs) { - if (bs->wakeup) { + /* The barrier (or an atomic op) is in the caller. */ + if (atomic_read(&bs->wakeup)) { aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL); } } diff --git a/block/nfs.c b/block/nfs.c index 0816678..fd2508a 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -736,7 +736,9 @@ nfs_get_allocated_file_size_cb(int ret, struct nfs_cont= ext *nfs, void *data, if (task->ret < 0) { error_report("NFS Error: %s", nfs_get_error(nfs)); } - task->complete =3D 1; + + /* Set task->complete before reading bs->wakeup. */ + atomic_mb_set(&task->complete, 1); bdrv_wakeup(task->bs); } =20 diff --git a/block/sheepdog.c b/block/sheepdog.c index fb9203e..7e90a24 100644 --- a/block/sheepdog.c +++ b/block/sheepdog.c @@ -704,7 +704,8 @@ out: =20 srco->co =3D NULL; srco->ret =3D ret; - srco->finished =3D true; + /* Set srco->finished before reading bs->wakeup. */ + atomic_mb_set(&srco->finished, true); if (srco->bs) { bdrv_wakeup(srco->bs); } diff --git a/include/block/block.h b/include/block/block.h index 5ddc0cf..486b6ed 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -398,7 +398,8 @@ void bdrv_drain_all(void); * block_job_defer_to_main_loop for how to do it). \ */ \ assert(!bs_->wakeup); \ - bs_->wakeup =3D true; \ + /* Set bs->wakeup before evaluating cond. */ \ + atomic_mb_set(&bs_->wakeup, true); \ while (busy_) { \ if ((cond)) { \ waited_ =3D busy_ =3D true; \ @@ -410,7 +411,7 @@ void bdrv_drain_all(void); waited_ |=3D busy_; \ } \ } \ - bs_->wakeup =3D false; \ + atomic_set(&bs_->wakeup, false); \ } \ waited_; }) =20 diff --git a/include/block/block_int.h b/include/block/block_int.h index 7317db6..ca34c99 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -590,8 +590,6 @@ struct BlockDriverState { /* Callback before write request is processed */ NotifierWithReturnList before_write_notifiers; =20 - bool wakeup; - /* Offset after the highest byte written to */ uint64_t wr_highest_offset; =20 @@ -622,6 +620,8 @@ struct BlockDriverState { unsigned int in_flight; unsigned int serialising_in_flight; =20 + bool wakeup; + /* do we need to tell the quest if we have a volatile write cache? */ int enable_write_cache; =20 --=20 2.9.3