From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56162) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bwCBa-00076G-Dh for qemu-devel@nongnu.org; Mon, 17 Oct 2016 13:58:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bwCBX-0004Wy-5l for qemu-devel@nongnu.org; Mon, 17 Oct 2016 13:58:54 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:21426 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 1bwCBW-0004W4-MV for qemu-devel@nongnu.org; Mon, 17 Oct 2016 13:58:51 -0400 References: <1475232808-4852-1-git-send-email-vsementsov@virtuozzo.com> <1475232808-4852-12-git-send-email-vsementsov@virtuozzo.com> <58051104.6020905@virtuozzo.com> From: Vladimir Sementsov-Ogievskiy Message-ID: <5805114B.8070104@virtuozzo.com> Date: Mon, 17 Oct 2016 20:58:35 +0300 MIME-Version: 1.0 In-Reply-To: <58051104.6020905@virtuozzo.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] DROP THIS Re: [PATCH 11/22] qcow2-bitmap: add qcow2_store_persistent_bitmaps() 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, armbru@redhat.com, eblake@redhat.com, jsnow@redhat.com, famz@redhat.com, den@openvz.org, stefanha@redhat.com, pbonzini@redhat.com Sorry, this was an accidental reply. On 17.10.2016 20:57, Vladimir Sementsov-Ogievskiy wrote: > On 30.09.2016 12:53, Vladimir Sementsov-Ogievskiy wrote: >> Realize block bitmap stroing interface, to allow qcow2 images store >> persistent bitmaps. >> >> Signed-off-by: Vladimir Sementsov-Ogievskiy >> --- >> block/qcow2-bitmap.c | 241 >> +++++++++++++++++++++++++++++++++++++++++++++++++++ >> block/qcow2.c | 2 + >> block/qcow2.h | 2 + >> 3 files changed, 245 insertions(+) >> >> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c >> index 81520cd..a5be25a 100644 >> --- a/block/qcow2-bitmap.c >> +++ b/block/qcow2-bitmap.c >> @@ -27,6 +27,7 @@ >> >> #include "qemu/osdep.h" >> #include "qapi/error.h" >> +#include "qemu/cutils.h" >> >> #include "block/block_int.h" >> #include "block/qcow2.h" >> @@ -96,6 +97,15 @@ static inline void bitmap_table_to_cpu(uint64_t >> *bitmap_table, size_t size) >> } >> } >> >> +static inline void bitmap_table_to_be(uint64_t *bitmap_table, size_t >> size) >> +{ >> + size_t i; >> + >> + for (i = 0; i < size; ++i) { >> + cpu_to_be64s(&bitmap_table[i]); >> + } >> +} >> + >> static inline int calc_dir_entry_size(size_t name_size, size_t >> extra_data_size) >> { >> return align_offset(sizeof(Qcow2BitmapDirEntry) + >> @@ -564,3 +574,234 @@ out: >> >> return ret; >> } >> + >> +/* store_bitmap_data() >> + * Store bitmap to image, filling bitamp table accordingly. > > >> + */ >> +static int store_bitmap_data(BlockDriverState *bs, BdrvDirtyBitmap >> *bitmap, >> + uint64_t *bitmap_table, uint32_t >> bitmap_table_size) >> +{ >> + int ret; >> + BDRVQcow2State *s = bs->opaque; >> + uint64_t sector, dsc; >> + uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); >> + int cl_size = s->cluster_size; > > > >> + uint8_t *buf = NULL; >> + uint32_t tb_size = >> + size_to_clusters(s, >> + bdrv_dirty_bitmap_serialization_size(bitmap, 0, >> bm_size)); > > >> + >> + BdrvDirtyBitmapIter *dbi; >> + >> + if (tb_size != bitmap_table_size) { >> + return -EINVAL; >> + } >> + >> + memset(bitmap_table, 0, bitmap_table_size * >> sizeof(bitmap_table[0])); > > >> + >> + dbi = bdrv_dirty_iter_new(bitmap, 0); >> + buf = g_malloc(cl_size); >> + dsc = dirty_sectors_in_cluster(s, bitmap); >> + >> + while ((sector = bdrv_dirty_iter_next(dbi)) != -1) { > > >> + uint64_t cluster = sector / dsc; >> + sector = cluster * dsc; > > > >> + uint64_t end = MIN(bm_size, sector + dsc); >> + uint64_t write_size = >> + bdrv_dirty_bitmap_serialization_size(bitmap, sector, end >> - sector); >> + >> + int64_t off = qcow2_alloc_clusters(bs, cl_size); >> + if (off < 0) { >> + ret = off; >> + goto finish; >> + } >> + bitmap_table[cluster] = off; >> + >> + bdrv_dirty_bitmap_serialize_part(bitmap, buf, sector, end); > > > >> + if (write_size < cl_size) { >> + memset(buf + write_size, 0, cl_size - write_size); >> + } >> + > > >> + ret = bdrv_pwrite(bs->file, off, buf, cl_size); >> + if (ret < 0) { >> + goto finish; >> + } >> + >> + if (end >= bm_size) { >> + break; >> + } >> + >> + bdrv_set_dirty_iter(dbi, end); >> + } >> + ret = 0; /* writes */ > > What is that comment supposed to mean? > >> + >> +finish: >> + if (ret < 0) { >> + clear_bitmap_table(bs, bitmap_table, bitmap_table_size); >> + } >> + g_free(buf); >> + bdrv_dirty_iter_free(dbi); >> + >> + return ret; > > In case you decide to keep BME_MAX_PHYS_SIZE, this function should check > somewhere that the physical size of the bitmap does not exceed that > value. > >> +} >> + >> +/* store_bitmap() >> + * Store bitmap to qcow2 and set bitmap_table. bitmap_table itself >> is not >> + * stored to qcow2. > > First of all, there is no parameter called "bitmap_table", and second, > yes, the bitmap table is written to the qcow2 file. > >> + */ >> +static int store_bitmap(BlockDriverState *bs, >> + BdrvDirtyBitmap *bitmap, >> + Qcow2BitmapDirEntry *entry) >> +{ >> + int ret; >> + BDRVQcow2State *s = bs->opaque; >> + uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap); >> + const char *bm_name = bdrv_dirty_bitmap_name(bitmap); >> + >> + uint64_t *tb; >> + int64_t tb_offset; >> + uint32_t tb_size = >> + size_to_clusters(s, >> + bdrv_dirty_bitmap_serialization_size(bitmap, 0, >> bm_size)); > > As above, this variable should be of type uint64_t. > > Also, you have to check that it does not exceed BME_MAX_TABLE_SIZE. > >> + >> + tb = g_try_new(uint64_t, tb_size); >> + if (tb == NULL) { >> + return -ENOMEM; >> + } >> + >> + ret = store_bitmap_data(bs, bitmap, tb, tb_size); >> + if (ret < 0) { >> + g_free(tb); >> + return ret; >> + } >> + >> + tb_offset = qcow2_alloc_clusters(bs, tb_size * sizeof(tb[0])); > > If you don't limit tb_size, then this multiplication can overflow on 32 > bit machines. > >> + if (tb_offset < 0) { >> + ret = tb_offset; >> + goto fail; >> + } >> + > > There should be a metadata overlap check here. > >> + bitmap_table_to_be(tb, tb_size); >> + ret = bdrv_pwrite(bs->file, tb_offset, tb, tb_size * >> sizeof(tb[0])); >> + if (ret < 0) { >> + goto fail; >> + } >> + >> + g_free(tb); >> + >> + entry->bitmap_table_offset = tb_offset; >> + entry->bitmap_table_size = tb_size; >> + entry->flags = bdrv_dirty_bitmap_granularity(bitmap) ? >> BME_FLAG_AUTO : 0; > > s/granularity/get_autoload/ > >> + entry->type = BT_DIRTY_TRACKING_BITMAP; >> + entry->granularity_bits = >> ctz32(bdrv_dirty_bitmap_granularity(bitmap)); > > You should probably check somewhere that the resulting value for > entry->granularity_bits is in the BME_{MIN,MAX}_GRANULARITY_BITS range. > >> + entry->name_size = strlen(bm_name); > > And that this length does not exceed BME_MAX_NAME_SIZE. > >> + entry->extra_data_size = 0; >> + memcpy(entry + 1, bm_name, entry->name_size); >> + >> + return 0; >> + >> +fail: >> + clear_bitmap_table(bs, tb, tb_size); >> + >> + if (tb_offset > 0) { >> + qcow2_free_clusters(bs, tb_offset, tb_size, >> QCOW2_DISCARD_ALWAYS); > > As before, I'd vote for QCOW2_DISCARD_OTHER. > >> + } >> + >> + g_free(tb); >> + >> + return ret; >> +} >> + >> +static Qcow2BitmapDirEntry *find_bitmap_by_name(uint8_t >> *bitmap_directory, >> + size_t size, const >> char *name) >> +{ >> + Qcow2BitmapDirEntry *e; >> + >> + for_each_bitmap_dir_entry(e, bitmap_directory, size) { >> + if (strncmp((char *)(e + 1), name, e->name_size) == 0) { >> + return e; >> + } >> + } >> + >> + return NULL; >> +} >> + >> +void qcow2_store_persistent_bitmaps(BlockDriverState *bs, Error **errp) >> +{ >> + BdrvDirtyBitmap *bm; >> + BDRVQcow2State *s = bs->opaque; >> + uint32_t new_nb_bitmaps = s->nb_bitmaps; >> + uint64_t new_dir_size = s->bitmap_directory_size; >> + uint8_t *dir = NULL, *new_dir = NULL; >> + int ret; >> + Qcow2BitmapDirEntry *new_pos; >> + >> + if (s->nb_bitmaps > 0) { >> + dir = directory_read(bs, s->bitmap_directory_offset, >> + s->bitmap_directory_size, errp); >> + if (dir == NULL) { >> + goto out; >> + } >> + } >> + >> + for (bm = bdrv_dirty_bitmap_next(bs, NULL); bm != NULL; >> + bm = bdrv_dirty_bitmap_next(bs, bm)) { >> + const char *name = bdrv_dirty_bitmap_name(bm); >> + >> + if (!bdrv_dirty_bitmap_get_persistance(bm)) { >> + continue; >> + } >> + >> + if (s->nb_bitmaps > 0 && >> + find_bitmap_by_name(dir, s->bitmap_directory_size, >> name)) { >> + error_setg(errp, >> + "Can't store bitmap '%s' to '%s', as it >> already exists", >> + name, bdrv_get_device_or_node_name(bs)); >> + goto out; >> + } >> + >> + new_nb_bitmaps++; >> + new_dir_size += calc_dir_entry_size(strlen(name), 0); >> + } >> + >> + if (s->nb_bitmaps == new_nb_bitmaps) { >> + /* No new bitmaps - nothing to do */ >> + goto out; >> + } >> + >> + new_dir = g_try_malloc0(new_dir_size); >> + if (new_dir == NULL) { >> + error_setg(errp, "Can't allocate space for bitmap directory."); >> + goto out; >> + } >> + >> + memcpy(new_dir, dir, s->bitmap_directory_size); >> + new_pos = (Qcow2BitmapDirEntry *)(new_dir + >> s->bitmap_directory_size); >> + >> + for (bm = bdrv_dirty_bitmap_next(bs, NULL); bm != NULL; >> + bm = bdrv_dirty_bitmap_next(bs, bm)) { >> + if (!bdrv_dirty_bitmap_get_persistance(bm)) { >> + continue; >> + } >> + >> + ret = store_bitmap(bs, bm, new_pos); >> + if (ret < 0) { >> + error_setg_errno(errp, -ret, "Can't store bitmap '%s' to >> '%s'", >> + bdrv_dirty_bitmap_name(bm), >> + bdrv_get_device_or_node_name(bs)); >> + goto out; >> + } >> + new_pos = next_dir_entry(new_pos); >> + } >> + >> + ret = directory_update(bs, new_dir, new_dir_size, new_nb_bitmaps); >> + if (ret < 0) { >> + error_setg_errno(errp, -ret, "Can't update bitmap directory >> in '%s'", >> + bdrv_get_device_or_node_name(bs)); >> + goto out; >> + } >> + >> +out: >> + g_free(new_dir); >> + g_free(dir); > > This error path leaks all the bitmaps that have been written > successfully (if any). I guess this is more or less fine if > directory_update() failed (because you can't really tell the state of > the image header after directory_update(), so better be safe) but it's > not so fine if just some store_bitmap() failed. > > Max > >> +} >> diff --git a/block/qcow2.c b/block/qcow2.c >> index 02ec224..8238205 100644 >> --- a/block/qcow2.c >> +++ b/block/qcow2.c >> @@ -3493,6 +3493,8 @@ BlockDriver bdrv_qcow2 = { >> >> .bdrv_detach_aio_context = qcow2_detach_aio_context, >> .bdrv_attach_aio_context = qcow2_attach_aio_context, >> + >> + .bdrv_store_persistent_bitmaps = qcow2_store_persistent_bitmaps, >> }; >> >> static void bdrv_qcow2_init(void) >> diff --git a/block/qcow2.h b/block/qcow2.h >> index 482a29f..dfcf4c6 100644 >> --- a/block/qcow2.h >> +++ b/block/qcow2.h >> @@ -627,4 +627,6 @@ int qcow2_cache_get_empty(BlockDriverState *bs, >> Qcow2Cache *c, uint64_t offset, >> void **table); >> void qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void >> **table); >> >> +void qcow2_store_persistent_bitmaps(BlockDriverState *bs, Error >> **errp); >> + >> #endif >> > > > -- Best regards, Vladimir