From patchwork Tue Jul 11 16:07:21 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 786722 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org 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 ozlabs.org (Postfix) with ESMTPS id 3x6SYh0lY5z9s5L for ; Wed, 12 Jul 2017 02:42:48 +1000 (AEST) Received: from localhost ([::1]:47503 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dUyFJ-0003mB-UH for incoming@patchwork.ozlabs.org; Tue, 11 Jul 2017 12:42:45 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45545) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dUxkI-0008WS-TX for qemu-devel@nongnu.org; Tue, 11 Jul 2017 12:10:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dUxkH-0006Kk-5G for qemu-devel@nongnu.org; Tue, 11 Jul 2017 12:10:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34170) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dUxkD-0006Gh-DW; Tue, 11 Jul 2017 12:10:37 -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 73574C08C337; Tue, 11 Jul 2017 16:10:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 73574C08C337 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=pass smtp.mailfrom=mreitz@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 73574C08C337 Received: from localhost (ovpn-204-123.brq.redhat.com [10.40.204.123]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1CE8060A9B; Tue, 11 Jul 2017 16:10:34 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Tue, 11 Jul 2017 18:07:21 +0200 Message-Id: <20170711160814.20941-33-mreitz@redhat.com> In-Reply-To: <20170711160814.20941-1-mreitz@redhat.com> References: <20170711160814.20941-1-mreitz@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]); Tue, 11 Jul 2017 16:10:36 +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] [PULL 32/85] 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: qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Vladimir Sementsov-Ogievskiy 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 Message-id: 20170628120530.31251-11-vsementsov@virtuozzo.com Signed-off-by: Max Reitz --- include/block/dirty-bitmap.h | 4 ++++ block/dirty-bitmap.c | 36 ++++++++++++++++++++++++++++++++++++ block/io.c | 8 ++++++++ blockdev.c | 6 ++++++ 4 files changed, 54 insertions(+) diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h index 05451c7..cb43fa3 100644 --- a/include/block/dirty-bitmap.h +++ b/include/block/dirty-bitmap.h @@ -71,6 +71,8 @@ void bdrv_dirty_bitmap_deserialize_ones(BdrvDirtyBitmap *bitmap, bool finish); void bdrv_dirty_bitmap_deserialize_finish(BdrvDirtyBitmap *bitmap); +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value); + /* Functions that require manual locking. */ void bdrv_dirty_bitmap_lock(BdrvDirtyBitmap *bitmap); void bdrv_dirty_bitmap_unlock(BdrvDirtyBitmap *bitmap); @@ -85,5 +87,7 @@ void bdrv_set_dirty_iter(BdrvDirtyBitmapIter *hbi, int64_t sector_num); int64_t bdrv_get_dirty_count(BdrvDirtyBitmap *bitmap); int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap); void bdrv_dirty_bitmap_truncate(BlockDriverState *bs); +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap); +bool bdrv_has_readonly_bitmaps(BlockDriverState *bs); #endif diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c index a8fe149..17d3068 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -46,6 +46,12 @@ struct BdrvDirtyBitmap { bool disabled; /* Bitmap is disabled. It ignores all writes 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 discards). + Such operations must fail and both the image + and this bitmap must remain unchanged while + this flag is set. */ QLIST_ENTRY(BdrvDirtyBitmap) list; }; @@ -505,6 +511,7 @@ void bdrv_set_dirty_bitmap_locked(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); } @@ -521,6 +528,7 @@ void bdrv_reset_dirty_bitmap_locked(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); } @@ -535,6 +543,7 @@ void bdrv_reset_dirty_bitmap(BdrvDirtyBitmap *bitmap, void bdrv_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap **out) { assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); bdrv_dirty_bitmap_lock(bitmap); if (!out) { hbitmap_reset_all(bitmap->bitmap); @@ -551,6 +560,7 @@ void bdrv_undo_clear_dirty_bitmap(BdrvDirtyBitmap *bitmap, HBitmap *in) { HBitmap *tmp = bitmap->bitmap; assert(bdrv_dirty_bitmap_enabled(bitmap)); + assert(!bdrv_dirty_bitmap_readonly(bitmap)); bitmap->bitmap = in; hbitmap_free(tmp); } @@ -613,6 +623,7 @@ void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, if (!bdrv_dirty_bitmap_enabled(bitmap)) { continue; } + assert(!bdrv_dirty_bitmap_readonly(bitmap)); hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); } bdrv_dirty_bitmaps_unlock(bs); @@ -635,3 +646,28 @@ int64_t bdrv_get_meta_dirty_count(BdrvDirtyBitmap *bitmap) { return hbitmap_count(bitmap->meta); } + +bool bdrv_dirty_bitmap_readonly(const BdrvDirtyBitmap *bitmap) +{ + return bitmap->readonly; +} + +/* Called with BQL taken. */ +void bdrv_dirty_bitmap_set_readonly(BdrvDirtyBitmap *bitmap, bool value) +{ + qemu_mutex_lock(bitmap->mutex); + bitmap->readonly = value; + qemu_mutex_unlock(bitmap->mutex); +} + +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 23170a5..b413727 100644 --- a/block/io.c +++ b/block/io.c @@ -1315,6 +1315,10 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child, uint64_t bytes_remaining = bytes; int max_transfer; + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + assert(is_power_of_2(align)); assert((offset & (align - 1)) == 0); assert((bytes & (align - 1)) == 0); @@ -2287,6 +2291,10 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset, return -ENOMEDIUM; } + if (bdrv_has_readonly_bitmaps(bs)) { + return -EPERM; + } + ret = bdrv_check_byte_request(bs, offset, bytes); if (ret < 0) { return ret; diff --git a/blockdev.c b/blockdev.c index 92c5991..edeb36b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2033,6 +2033,9 @@ static void block_dirty_bitmap_clear_prepare(BlkActionState *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; } bdrv_clear_dirty_bitmap(state->bitmap, &state->backup); @@ -2779,6 +2782,9 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name, "Bitmap '%s' is currently disabled and cannot be cleared", name); return; + } else if (bdrv_dirty_bitmap_readonly(bitmap)) { + error_setg(errp, "Bitmap '%s' is readonly and cannot be cleared", name); + return; } bdrv_clear_dirty_bitmap(bitmap, NULL);