diff options
Diffstat (limited to 'block/qcow2-bitmap.c')
| -rw-r--r-- | block/qcow2-bitmap.c | 170 |
1 files changed, 117 insertions, 53 deletions
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 9d968bdcda..e53a1609d7 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -343,11 +343,17 @@ static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, uint32_t granularity; BdrvDirtyBitmap *bitmap = NULL; - if (bm->flags & BME_FLAG_IN_USE) { - error_setg(errp, "Bitmap '%s' is in use", bm->name); + granularity = 1U << bm->granularity_bits; + bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp); + if (bitmap == NULL) { goto fail; } + if (bm->flags & BME_FLAG_IN_USE) { + /* Data is unusable, skip loading it */ + return bitmap; + } + ret = bitmap_table_load(bs, &bm->table, &bitmap_table); if (ret < 0) { error_setg_errno(errp, -ret, @@ -356,12 +362,6 @@ static BdrvDirtyBitmap *load_bitmap(BlockDriverState *bs, goto fail; } - granularity = 1U << bm->granularity_bits; - bitmap = bdrv_create_dirty_bitmap(bs, granularity, bm->name, errp); - if (bitmap == NULL) { - goto fail; - } - ret = load_bitmap_data(bs, bitmap_table, bm->table.size, bitmap); if (ret < 0) { error_setg_errno(errp, -ret, "Could not read bitmap '%s' from image", @@ -462,10 +462,25 @@ static int check_dir_entry(BlockDriverState *bs, Qcow2BitmapDirEntry *entry) return len; } - fail = (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) || - (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)); + if (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) { + return -EINVAL; + } + + if (!(entry->flags & BME_FLAG_IN_USE) && + (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits))) + { + /* + * We've loaded a valid bitmap (IN_USE not set) or we are going to + * store a valid bitmap, but the allocated bitmap table size is not + * enough to store this bitmap. + * + * Note, that it's OK to have an invalid bitmap with invalid size due + * to a bitmap that was not correctly saved after image resize. + */ + return -EINVAL; + } - return fail ? -EINVAL : 0; + return 0; } static inline void bitmap_directory_to_be(uint8_t *dir, size_t size) @@ -950,6 +965,7 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) Qcow2Bitmap *bm; GSList *created_dirty_bitmaps = NULL; bool header_updated = false; + bool needs_update = false; if (s->nb_bitmaps == 0) { /* No bitmaps - nothing to do */ @@ -963,35 +979,39 @@ bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp) } QSIMPLEQ_FOREACH(bm, bm_list, entry) { - if (!(bm->flags & BME_FLAG_IN_USE)) { - BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); - if (bitmap == NULL) { - goto fail; - } + BdrvDirtyBitmap *bitmap = load_bitmap(bs, bm, errp); + if (bitmap == NULL) { + goto fail; + } - if (!(bm->flags & BME_FLAG_AUTO)) { - bdrv_disable_dirty_bitmap(bitmap); - } - bdrv_dirty_bitmap_set_persistance(bitmap, true); + bdrv_dirty_bitmap_set_persistence(bitmap, true); + if (bm->flags & BME_FLAG_IN_USE) { + bdrv_dirty_bitmap_set_inconsistent(bitmap); + } else { + /* NB: updated flags only get written if can_write(bs) is true. */ bm->flags |= BME_FLAG_IN_USE; - created_dirty_bitmaps = - g_slist_append(created_dirty_bitmaps, bitmap); + needs_update = true; + } + if (!(bm->flags & BME_FLAG_AUTO)) { + bdrv_disable_dirty_bitmap(bitmap); } + created_dirty_bitmaps = + g_slist_append(created_dirty_bitmaps, bitmap); } - if (created_dirty_bitmaps != NULL) { - if (can_write(bs)) { - /* in_use flags must be updated */ - int ret = update_ext_header_and_dir_in_place(bs, bm_list); - if (ret < 0) { - error_setg_errno(errp, -ret, "Can't update bitmap directory"); - goto fail; - } - header_updated = true; - } else { - g_slist_foreach(created_dirty_bitmaps, set_readonly_helper, - (gpointer)true); + if (needs_update && can_write(bs)) { + /* in_use flags must be updated */ + int ret = update_ext_header_and_dir_in_place(bs, bm_list); + if (ret < 0) { + error_setg_errno(errp, -ret, "Can't update bitmap directory"); + goto fail; } + header_updated = true; + } + + if (!can_write(bs)) { + g_slist_foreach(created_dirty_bitmaps, set_readonly_helper, + (gpointer)true); } g_slist_free(created_dirty_bitmaps); @@ -1113,23 +1133,21 @@ int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated, } QSIMPLEQ_FOREACH(bm, bm_list, entry) { - if (!(bm->flags & BME_FLAG_IN_USE)) { - BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); - if (bitmap == NULL) { - continue; - } - - if (!bdrv_dirty_bitmap_readonly(bitmap)) { - error_setg(errp, "Bitmap %s is not readonly but not marked" - "'IN_USE' in the image. Something went wrong," - "all the bitmaps may be corrupted", bm->name); - ret = -EINVAL; - goto out; - } + BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); + if (bitmap == NULL) { + continue; + } - bm->flags |= BME_FLAG_IN_USE; - ro_dirty_bitmaps = g_slist_append(ro_dirty_bitmaps, bitmap); + if (!bdrv_dirty_bitmap_readonly(bitmap)) { + error_setg(errp, "Bitmap %s was loaded prior to rw-reopen, but was " + "not marked as readonly. This is a bug, something went " + "wrong. All of the bitmaps may be corrupted", bm->name); + ret = -EINVAL; + goto out; } + + bm->flags |= BME_FLAG_IN_USE; + ro_dirty_bitmaps = g_slist_append(ro_dirty_bitmaps, bitmap); } if (ro_dirty_bitmaps != NULL) { @@ -1157,6 +1175,52 @@ int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp) return qcow2_reopen_bitmaps_rw_hint(bs, NULL, errp); } +/* Checks to see if it's safe to resize bitmaps */ +int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp) +{ + BDRVQcow2State *s = bs->opaque; + Qcow2BitmapList *bm_list; + Qcow2Bitmap *bm; + int ret = 0; + + if (s->nb_bitmaps == 0) { + return 0; + } + + bm_list = bitmap_list_load(bs, s->bitmap_directory_offset, + s->bitmap_directory_size, errp); + if (bm_list == NULL) { + return -EINVAL; + } + + QSIMPLEQ_FOREACH(bm, bm_list, entry) { + BdrvDirtyBitmap *bitmap = bdrv_find_dirty_bitmap(bs, bm->name); + if (bitmap == NULL) { + /* + * We rely on all bitmaps being in-memory to be able to resize them, + * Otherwise, we'd need to resize them on disk explicitly + */ + error_setg(errp, "Cannot resize qcow2 with persistent bitmaps that " + "were not loaded into memory"); + ret = -ENOTSUP; + goto out; + } + + /* + * The checks against readonly and busy are redundant, but certainly + * do no harm. checks against inconsistent are crucial: + */ + if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, errp)) { + ret = -ENOTSUP; + goto out; + } + } + +out: + bitmap_list_free(bm_list); + return ret; +} + /* store_bitmap_data() * Store bitmap to image, filling bitmap table accordingly. */ @@ -1424,9 +1488,9 @@ void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs, Error **errp) uint32_t granularity = bdrv_dirty_bitmap_granularity(bitmap); Qcow2Bitmap *bm; - if (!bdrv_dirty_bitmap_get_persistance(bitmap) || - bdrv_dirty_bitmap_readonly(bitmap)) - { + if (!bdrv_dirty_bitmap_get_persistence(bitmap) || + bdrv_dirty_bitmap_readonly(bitmap) || + bdrv_dirty_bitmap_inconsistent(bitmap)) { continue; } @@ -1542,7 +1606,7 @@ int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp) for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap != NULL; bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) { - if (bdrv_dirty_bitmap_get_persistance(bitmap)) { + if (bdrv_dirty_bitmap_get_persistence(bitmap)) { bdrv_dirty_bitmap_set_readonly(bitmap, true); } } |