From nobody Mon Feb 9 00:19:31 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; 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 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=virtuozzo.com ARC-Seal: i=1; a=rsa-sha256; t=1568968091; cv=none; d=zoho.com; s=zohoarc; b=cMaTrS+Dtj+b70zeDD3OwkW5kRMpr4DtENL3XzgQoLFAuZI5BJ7ZUNXNkbGtd9Nwn4USa8JVj9RVO7S5zg/RMz1mFebdbmOJvdi0NnZ2rXUwvyI6ler3SOqh8axOFICeWYOB4eYJW7kFoiE/nuFyxj4KIRhio2ibq64piAw+TtA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1568968091; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=3SBHkhmCXiRZGJ2iRYXarJBcHOPIDzABk9qRYp6A4MA=; b=Nhx9I9b3+Yxnny93QQP0z8Q7X8GirL4PKj6mSJhVseO3WDYax8o8srXMpsSuiMEhXd+TaRxH1UmellHYX7JZ/wqaAhMAnwY65znitKW64/8SS4jsTQd4f8buRb5Ww5NQRwGHQzEQFyfxuh/WkJuv1SlboEXhWZ9+MiseWsrxHU0= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (209.51.188.17 [209.51.188.17]) by mx.zohomail.com with SMTPS id 1568968091211925.7423302197178; Fri, 20 Sep 2019 01:28:11 -0700 (PDT) Received: from localhost ([::1]:55972 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBEGp-0001lS-RE for importer@patchew.org; Fri, 20 Sep 2019 04:28:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42655) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBEEj-0008Gn-2w for qemu-devel@nongnu.org; Fri, 20 Sep 2019 04:25:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iBEEg-0005Pw-VQ for qemu-devel@nongnu.org; Fri, 20 Sep 2019 04:25:52 -0400 Received: from relay.sw.ru ([185.231.240.75]:60534) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iBEEc-0005Ne-PU; Fri, 20 Sep 2019 04:25:46 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.2) (envelope-from ) id 1iBEEZ-0004DS-QJ; Fri, 20 Sep 2019 11:25:43 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org Subject: [PATCH v3 3/3] block/qcow2: proper locking on bitmap add/remove paths Date: Fri, 20 Sep 2019 11:25:43 +0300 Message-Id: <20190920082543.23444-4-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190920082543.23444-1-vsementsov@virtuozzo.com> References: <20190920082543.23444-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 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: fam@euphon.net, kwolf@redhat.com, vsementsov@virtuozzo.com, armbru@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" qmp_block_dirty_bitmap_add and do_block_dirty_bitmap_remove do acquire aio context since 0a6c86d024c52b. But this is not enough: we also must lock qcow2 mutex when access in-image metadata. Especially it concerns freeing qcow2 clusters. To achieve this, move qcow2_can_store_new_dirty_bitmap and qcow2_remove_persistent_dirty_bitmap to coroutine context. Since we work in coroutines in correct aio context, we don't need context acquiring in blockdev.c anymore, drop it. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: John Snow --- block/qcow2.h | 11 ++-- include/block/block_int.h | 10 ++-- block/dirty-bitmap.c | 102 +++++++++++++++++++++++++++++++++++--- block/qcow2-bitmap.c | 24 ++++++--- block/qcow2.c | 5 +- blockdev.c | 27 +++------- 6 files changed, 131 insertions(+), 48 deletions(-) diff --git a/block/qcow2.h b/block/qcow2.h index 2ed5482163..113d99bf52 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -743,12 +743,13 @@ int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Err= or **errp); int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp); void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **er= rp); int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp); -bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, - const char *name, - uint32_t granularity, - Error **errp); -int qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char = *name, +bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, + const char *name, + uint32_t granularity, Error **errp); +int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, + const char *name, + Error **errp); =20 ssize_t coroutine_fn qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size, diff --git a/include/block/block_int.h b/include/block/block_int.h index 503ac9e3cd..1e54486ad1 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -552,13 +552,13 @@ struct BlockDriver { * field of BlockDirtyBitmap's in case of success. */ int (*bdrv_reopen_bitmaps_rw)(BlockDriverState *bs, Error **errp); - bool (*bdrv_can_store_new_dirty_bitmap)(BlockDriverState *bs, - const char *name, - uint32_t granularity, - Error **errp); - int (*bdrv_remove_persistent_dirty_bitmap)(BlockDriverState *bs, + bool (*bdrv_co_can_store_new_dirty_bitmap)(BlockDriverState *bs, const char *name, + uint32_t granularity, Error **errp); + int (*bdrv_co_remove_persistent_dirty_bitmap)(BlockDriverState *bs, + const char *name, + Error **errp); =20 /** * Register/unregister a buffer for I/O. For example, when the driver = is diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index d1ae2e1922..03e0872b97 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -26,6 +26,7 @@ #include "trace.h" #include "block/block_int.h" #include "block/blockjob.h" +#include "qemu/main-loop.h" =20 struct BdrvDirtyBitmap { QemuMutex *mutex; @@ -455,18 +456,59 @@ void bdrv_release_named_dirty_bitmaps(BlockDriverStat= e *bs) * not fail. * This function doesn't release corresponding BdrvDirtyBitmap. */ -int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *= name, - Error **errp) +static int coroutine_fn +bdrv_co_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *n= ame, + Error **errp) { - if (bs->drv && bs->drv->bdrv_remove_persistent_dirty_bitmap) { - return bs->drv->bdrv_remove_persistent_dirty_bitmap(bs, name, errp= ); + if (bs->drv && bs->drv->bdrv_co_remove_persistent_dirty_bitmap) { + return bs->drv->bdrv_co_remove_persistent_dirty_bitmap(bs, name, e= rrp); } =20 return 0; } =20 -bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *nam= e, - uint32_t granularity, Error **errp) +typedef struct BdrvRemovePersistentDirtyBitmapCo { + BlockDriverState *bs; + const char *name; + Error **errp; + int ret; +} BdrvRemovePersistentDirtyBitmapCo; + +static void coroutine_fn +bdrv_co_remove_persistent_dirty_bitmap_entry(void *opaque) +{ + BdrvRemovePersistentDirtyBitmapCo *s =3D opaque; + + s->ret =3D bdrv_co_remove_persistent_dirty_bitmap(s->bs, s->name, s->e= rrp); + aio_wait_kick(); +} + +int bdrv_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char *= name, + Error **errp) +{ + if (qemu_in_coroutine()) { + return bdrv_co_remove_persistent_dirty_bitmap(bs, name, errp); + } else { + Coroutine *co; + BdrvRemovePersistentDirtyBitmapCo s =3D { + .bs =3D bs, + .name =3D name, + .errp =3D errp, + .ret =3D -EINPROGRESS, + }; + + co =3D qemu_coroutine_create(bdrv_co_remove_persistent_dirty_bitma= p_entry, + &s); + bdrv_coroutine_enter(bs, co); + BDRV_POLL_WHILE(bs, s.ret =3D=3D -EINPROGRESS); + + return s.ret; + } +} + +static bool coroutine_fn +bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name, + uint32_t granularity, Error **errp) { BlockDriver *drv =3D bs->drv; =20 @@ -477,14 +519,58 @@ bool bdrv_can_store_new_dirty_bitmap(BlockDriverState= *bs, const char *name, return false; } =20 - if (!drv->bdrv_can_store_new_dirty_bitmap) { + if (!drv->bdrv_co_can_store_new_dirty_bitmap) { error_setg_errno(errp, ENOTSUP, "Can't store persistent bitmaps to %s", bdrv_get_device_or_node_name(bs)); return false; } =20 - return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, err= p); + return drv->bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, = errp); +} + +typedef struct BdrvCanStoreNewDirtyBitmapCo { + BlockDriverState *bs; + const char *name; + uint32_t granularity; + Error **errp; + bool ret; + + bool in_progress; +} BdrvCanStoreNewDirtyBitmapCo; + +static void coroutine_fn bdrv_co_can_store_new_dirty_bitmap_entry(void *op= aque) +{ + BdrvCanStoreNewDirtyBitmapCo *s =3D opaque; + + s->ret =3D bdrv_co_can_store_new_dirty_bitmap(s->bs, s->name, s->granu= larity, + s->errp); + s->in_progress =3D false; + aio_wait_kick(); +} + +bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *nam= e, + uint32_t granularity, Error **errp) +{ + if (qemu_in_coroutine()) { + return bdrv_co_can_store_new_dirty_bitmap(bs, name, granularity, e= rrp); + } else { + Coroutine *co; + BdrvCanStoreNewDirtyBitmapCo s =3D { + .bs =3D bs, + .name =3D name, + .granularity =3D granularity, + .errp =3D errp, + .in_progress =3D true, + }; + + co =3D qemu_coroutine_create(bdrv_co_can_store_new_dirty_bitmap_en= try, + &s); + bdrv_coroutine_enter(bs, co); + BDRV_POLL_WHILE(bs, s.in_progress); + + return s.ret; + } } =20 void bdrv_disable_dirty_bitmap(BdrvDirtyBitmap *bitmap) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 9821c1628f..644837eb03 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -1404,12 +1404,13 @@ static Qcow2Bitmap *find_bitmap_by_name(Qcow2Bitmap= List *bm_list, return NULL; } =20 -int qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs, const char = *name, - Error **errp) +int coroutine_fn qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState = *bs, + const char *name, + Error **errp) { int ret; BDRVQcow2State *s =3D bs->opaque; - Qcow2Bitmap *bm; + Qcow2Bitmap *bm =3D NULL; Qcow2BitmapList *bm_list; =20 if (s->nb_bitmaps =3D=3D 0) { @@ -1418,10 +1419,13 @@ int qcow2_remove_persistent_dirty_bitmap(BlockDrive= rState *bs, const char *name, return 0; } =20 + qemu_co_mutex_lock(&s->lock); + bm_list =3D bitmap_list_load(bs, s->bitmap_directory_offset, s->bitmap_directory_size, errp); if (bm_list =3D=3D NULL) { - return -EIO; + ret =3D -EIO; + goto out; } =20 bm =3D find_bitmap_by_name(bm_list, name); @@ -1441,6 +1445,8 @@ int qcow2_remove_persistent_dirty_bitmap(BlockDriverS= tate *bs, const char *name, free_bitmap_clusters(bs, &bm->table); =20 out: + qemu_co_mutex_unlock(&s->lock); + bitmap_free(bm); bitmap_list_free(bm_list); =20 @@ -1615,10 +1621,10 @@ int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, E= rror **errp) return 0; } =20 -bool qcow2_can_store_new_dirty_bitmap(BlockDriverState *bs, - const char *name, - uint32_t granularity, - Error **errp) +bool coroutine_fn qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs, + const char *name, + uint32_t granularity, + Error **errp) { BDRVQcow2State *s =3D bs->opaque; bool found; @@ -1655,8 +1661,10 @@ bool qcow2_can_store_new_dirty_bitmap(BlockDriverSta= te *bs, goto fail; } =20 + qemu_co_mutex_lock(&s->lock); bm_list =3D bitmap_list_load(bs, s->bitmap_directory_offset, s->bitmap_directory_size, errp); + qemu_co_mutex_unlock(&s->lock); if (bm_list =3D=3D NULL) { goto fail; } diff --git a/block/qcow2.c b/block/qcow2.c index 4d16393e61..43a6cc423d 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -5263,8 +5263,9 @@ BlockDriver bdrv_qcow2 =3D { .bdrv_attach_aio_context =3D qcow2_attach_aio_context, =20 .bdrv_reopen_bitmaps_rw =3D qcow2_reopen_bitmaps_rw, - .bdrv_can_store_new_dirty_bitmap =3D qcow2_can_store_new_dirty_bitmap, - .bdrv_remove_persistent_dirty_bitmap =3D qcow2_remove_persistent_dirty= _bitmap, + .bdrv_co_can_store_new_dirty_bitmap =3D qcow2_co_can_store_new_dirty_b= itmap, + .bdrv_co_remove_persistent_dirty_bitmap =3D + qcow2_co_remove_persistent_dirty_bitmap, }; =20 static void bdrv_qcow2_init(void) diff --git a/blockdev.c b/blockdev.c index 0813adfb2b..228ce94a88 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2898,16 +2898,10 @@ void qmp_block_dirty_bitmap_add(const char *node, c= onst char *name, disabled =3D false; } =20 - if (persistent) { - AioContext *aio_context =3D bdrv_get_aio_context(bs); - bool ok; - - aio_context_acquire(aio_context); - ok =3D bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp= ); - aio_context_release(aio_context); - if (!ok) { - return; - } + if (persistent && + !bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp)) + { + return; } =20 bitmap =3D bdrv_create_dirty_bitmap(bs, granularity, name, errp); @@ -2939,17 +2933,10 @@ static BdrvDirtyBitmap *do_block_dirty_bitmap_remov= e( return NULL; } =20 - if (bdrv_dirty_bitmap_get_persistence(bitmap)) { - int ret; - AioContext *aio_context =3D bdrv_get_aio_context(bs); - - aio_context_acquire(aio_context); - ret =3D bdrv_remove_persistent_dirty_bitmap(bs, name, errp); - aio_context_release(aio_context); - - if (ret < 0) { + if (bdrv_dirty_bitmap_get_persistence(bitmap) && + bdrv_remove_persistent_dirty_bitmap(bs, name, errp) < 0) + { return NULL; - } } =20 if (release) { --=20 2.21.0