From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36202) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGkej-0006Hu-P5 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:22:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGkef-0005bj-H0 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:22:13 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:18677 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 1dGkef-0005ZB-04 for qemu-devel@nongnu.org; Fri, 02 Jun 2017 07:22:09 -0400 From: Vladimir Sementsov-Ogievskiy Date: Fri, 2 Jun 2017 14:21:38 +0300 Message-Id: <20170602112158.232757-11-vsementsov@virtuozzo.com> In-Reply-To: <20170602112158.232757-1-vsementsov@virtuozzo.com> References: <20170602112158.232757-1-vsementsov@virtuozzo.com> Subject: [Qemu-devel] [PATCH v20 10/30] block/dirty-bitmap: add readonly field to BdrvDirtyBitmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: kwolf@redhat.com, mreitz@redhat.com, armbru@redhat.com, eblake@redhat.com, jsnow@redhat.com, famz@redhat.com, den@openvz.org, stefanha@redhat.com, vsementsov@virtuozzo.com, pbonzini@redhat.com 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 --- 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 f25428868c..1c9ffb292a 100644 --- a/block/dirty-bitmap.c +++ b/block/dirty-bitmap.c @@ -45,6 +45,12 @@ struct BdrvDirtyBitmap { bool disabled; /* Bitmap is disabled. It skips all writes to the device */ int active_iterators; /* How many iterators are active */ + bool readonly; /* Bitmap is read-only and may be changed only + by deserialize* functions. This field blocks + any changing operations on owning image + (writes and discards), if bitmap is readonly + such operations must fail and not change + image or this bitmap */ QLIST_ENTRY(BdrvDirtyBitmap) list; }; @@ -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); } @@ -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); } 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_sector, 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 *bitmap) { 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 = 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(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); @@ -2437,6 +2441,10 @@ 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, 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(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); @@ -2813,6 +2816,9 @@ void qmp_block_dirty_bitmap_clear(const char *node, const char *name, "Bitmap '%s' is currently disabled and cannot be cleared", name); goto out; + } else if (bdrv_dirty_bitmap_readonly(bitmap)) { + error_setg(errp, "Bitmap '%s' is readonly and cannot be cleared", name); + goto out; } 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); +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 -- 2.11.1