From nobody Wed Nov 5 15:48:19 2025 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.zoho.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 1497362934703662.320260264967; Tue, 13 Jun 2017 07:08:54 -0700 (PDT) Received: from localhost ([::1]:43464 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKmV0-0006J4-7K for importer@patchew.org; Tue, 13 Jun 2017 10:08:50 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59707) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKmQU-0001hN-QD for qemu-devel@nongnu.org; Tue, 13 Jun 2017 10:04:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dKmQR-0005Jr-1u for qemu-devel@nongnu.org; Tue, 13 Jun 2017 10:04:10 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:13351 helo=relay.sw.ru) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dKmQQ-0005HH-HL for qemu-devel@nongnu.org; Tue, 13 Jun 2017 10:04:06 -0400 Received: from kvm.sw.ru (msk-vpn.virtuozzo.com [195.214.232.6]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id v5DE3wqx032717; Tue, 13 Jun 2017 17:04:00 +0300 (MSK) From: Vladimir Sementsov-Ogievskiy To: qemu-block@nongnu.org, qemu-devel@nongnu.org Date: Tue, 13 Jun 2017 17:03:38 +0300 Message-Id: <20170613140358.81651-11-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20170613140358.81651-1-vsementsov@virtuozzo.com> References: <20170613140358.81651-1-vsementsov@virtuozzo.com> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x [fuzzy] X-Received-From: 195.214.232.25 Subject: [Qemu-devel] [PATCH v21 10/30] block/dirty-bitmap: add readonly field to BdrvDirtyBitmap 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: kwolf@redhat.com, vsementsov@virtuozzo.com, famz@redhat.com, armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, den@openvz.org, 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 will be needed in following commits for persistent bitmaps. If bitmap is loaded from read-only storage (and we can't mark it "in use" in this storage) corresponding BdrvDirtyBitmap should be read-only. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: John Snow Reviewed-by: Max Reitz --- block/dirty-bitmap.c | 32 ++++++++++++++++++++++++++++++++ block/io.c | 8 ++++++++ blockdev.c | 6 ++++++ include/block/dirty-bitmap.h | 4 ++++ 4 files changed, 50 insertions(+) diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index 573510229a..e18166c968 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -45,6 +45,12 @@ struct BdrvDirtyBitmap { bool disabled; /* Bitmap is disabled. It ignores all writ= es to the device */ int active_iterators; /* How many iterators are active */ + bool readonly; /* Bitmap is read-only. This field also + prevents the respective image from being + modified (i.e. blocks writes and discar= ds). + Such operations must fail and both the = image + and this bitmap must remain unchanged w= hile + this flag is set. */ QLIST_ENTRY(BdrvDirtyBitmap) list; }; =20 @@ -437,6 +443,7 @@ void bdrv_set_dirty_bitmap(BdrvDirtyBitmap *bitmap, int64_t cur_sector, int64_t nr_sectors) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); } =20 @@ -444,12 +451,14 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, int64_t cur_sector, int64_t nr_sectors) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); } =20 void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); if (!out) { hbitmap_reset_all(bitmap->bitmap); } else { @@ -520,6 +529,7 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_s= ector, if (!bdrv_dirty_bitmap_enabled(bitmap)) { continue; } + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); } } @@ -541,3 +551,25 @@ int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bit= map) { return hbitmap_count(bitmap->meta); } + +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap) +{ + return bitmap->readonly; +} + +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value) +{ + bitmap->readonly =3D value; +} + +bool bdrv_has_readonly_bitmaps(BlockDriverState *bs) +{ + BdrvDirtyBitmap *bm; + QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { + if (bm->readonly) { + return true; + } + } + + return false; +} diff --git a/block/io.c b/block/io.c index fdd7485c22..0e28a1f595 100644 --- a/block/io.c +++ b/block/io.c @@ -1349,6 +1349,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChi= ld *child, uint64_t bytes_remaining =3D bytes; int max_transfer; =20 + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + assert(is_power_of_2(align)); assert((offset & (align - 1)) =3D=3D 0); assert((bytes & (align - 1)) =3D=3D 0); @@ -2437,6 +2441,10 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *= bs, int64_t offset, return -ENOMEDIUM; } =20 + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + ret =3D bdrv_check_byte_request(bs, offset, count); if (ret < 0) { return ret; diff --git a/blockdev.c b/blockdev.c index c63f4e82c7..2b397abf66 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2033,6 +2033,9 @@ static void block_dirty_bitmap_clear_prepare(BlkActio= nState *common, } else if (!bdrv_dirty_bitmap_enabled(state->bitmap)) { error_setg(errp, "Cannot clear a disabled bitmap"); return; + } else if (bdrv_dirty_bitmap_readonly(state->bitmap)) { + error_setg(errp, "Cannot clear a readonly bitmap"); + return; } =20 bdrv_clear_dirty_bitmap(state->bitmap, &state->backup); @@ -2813,6 +2816,9 @@ void qmp_block_dirty_bitmap_clear(const char *node, c= onst char *name, "Bitmap '%s' is currently disabled and cannot be cleare= d", name); goto out; + } else if (bdrv_dirty_bitmap_readonly(bitmap)) { + error_setg(errp, "Bitmap '%s' is readonly and cannot be cleared", = name); + goto out; } =20 bdrv_clear_dirty_bitmap(bitmap, NULL); diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index 1e17729ac2..aa6d47ee00 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -75,4 +75,8 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *= bitmap, bool finish); void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap); =20 +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap); +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value); +bool bdrv_has_readonly_bitmaps(BlockDriverState *bs); + #endif --=20 2.11.1