diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 364 |
1 files changed, 272 insertions, 92 deletions
@@ -49,12 +49,12 @@ #include <windows.h> #endif -#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ +struct BdrvDirtyBitmap { + HBitmap *bitmap; + QLIST_ENTRY(BdrvDirtyBitmap) list; +}; -typedef enum { - BDRV_REQ_COPY_ON_READ = 0x1, - BDRV_REQ_ZERO_WRITE = 0x2, -} BdrvRequestFlags; +#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, @@ -84,7 +84,7 @@ static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, bool is_write); static void coroutine_fn bdrv_co_do_rw(void *opaque); static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, - int64_t sector_num, int nb_sectors); + int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); static QTAILQ_HEAD(, BlockDriverState) bdrv_states = QTAILQ_HEAD_INITIALIZER(bdrv_states); @@ -323,6 +323,7 @@ BlockDriverState *bdrv_new(const char *device_name) BlockDriverState *bs; bs = g_malloc0(sizeof(BlockDriverState)); + QLIST_INIT(&bs->dirty_bitmaps); pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); if (device_name[0] != '\0') { QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); @@ -1052,21 +1053,16 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, int64_t total_size; BlockDriver *bdrv_qcow2; QEMUOptionParameter *create_options; - char backing_filename[PATH_MAX]; - - if (qdict_size(options) != 0) { - error_setg(errp, "Can't use snapshot=on with driver-specific options"); - ret = -EINVAL; - goto fail; - } - assert(filename != NULL); + QDict *snapshot_options; /* if snapshot, we create a temporary backing file and open it instead of opening 'filename' directly */ - /* if there is a backing file, use it */ + /* Get the required size from the image */ bs1 = bdrv_new(""); - ret = bdrv_open(bs1, filename, NULL, 0, drv, &local_err); + QINCREF(options); + ret = bdrv_open(bs1, filename, options, BDRV_O_NO_BACKING, + drv, &local_err); if (ret < 0) { bdrv_unref(bs1); goto fail; @@ -1075,33 +1071,18 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, bdrv_unref(bs1); + /* Create the temporary image */ ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename)); if (ret < 0) { error_setg_errno(errp, -ret, "Could not get temporary filename"); goto fail; } - /* Real path is meaningless for protocols */ - if (path_has_protocol(filename)) { - snprintf(backing_filename, sizeof(backing_filename), - "%s", filename); - } else if (!realpath(filename, backing_filename)) { - ret = -errno; - error_setg_errno(errp, errno, "Could not resolve path '%s'", filename); - goto fail; - } - bdrv_qcow2 = bdrv_find_format("qcow2"); create_options = parse_option_parameters("", bdrv_qcow2->create_options, NULL); set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size); - set_option_parameter(create_options, BLOCK_OPT_BACKING_FILE, - backing_filename); - if (drv) { - set_option_parameter(create_options, BLOCK_OPT_BACKING_FMT, - drv->format_name); - } ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options, &local_err); free_option_parameters(create_options); @@ -1114,6 +1095,22 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options, goto fail; } + /* Prepare a new options QDict for the temporary file, where user + * options refer to the backing file */ + if (filename) { + qdict_put(options, "file.filename", qstring_from_str(filename)); + } + if (drv) { + qdict_put(options, "driver", qstring_from_str(drv->format_name)); + } + + snapshot_options = qdict_new(); + qdict_put(snapshot_options, "backing", options); + qdict_flatten(snapshot_options); + + bs->options = snapshot_options; + options = qdict_clone_shallow(bs->options); + filename = tmp_filename; drv = bdrv_qcow2; bs->is_temporary = 1; @@ -1622,7 +1619,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest, bs_dest->iostatus = bs_src->iostatus; /* dirty bitmap */ - bs_dest->dirty_bitmap = bs_src->dirty_bitmap; + bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps; /* reference count */ bs_dest->refcnt = bs_src->refcnt; @@ -1655,7 +1652,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) /* bs_new must be anonymous and shouldn't have anything fancy enabled */ assert(bs_new->device_name[0] == '\0'); - assert(bs_new->dirty_bitmap == NULL); + assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); assert(bs_new->job == NULL); assert(bs_new->dev == NULL); assert(bs_new->in_use == 0); @@ -1716,6 +1713,7 @@ static void bdrv_delete(BlockDriverState *bs) assert(!bs->job); assert(!bs->in_use); assert(!bs->refcnt); + assert(QLIST_EMPTY(&bs->dirty_bitmaps)); bdrv_close(bs); @@ -2397,10 +2395,48 @@ int bdrv_writev(BlockDriverState *bs, int64_t sector_num, QEMUIOVector *qiov) return bdrv_rwv_co(bs, sector_num, qiov, true, 0); } -int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, int nb_sectors) +int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, BdrvRequestFlags flags) { return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, - BDRV_REQ_ZERO_WRITE); + BDRV_REQ_ZERO_WRITE | flags); +} + +/* + * Completely zero out a block device with the help of bdrv_write_zeroes. + * The operation is sped up by checking the block status and only writing + * zeroes to the device if they currently do not return zeroes. Optional + * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). + * + * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). + */ +int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags) +{ + int64_t target_size = bdrv_getlength(bs) / BDRV_SECTOR_SIZE; + int64_t ret, nb_sectors, sector_num = 0; + int n; + + for (;;) { + nb_sectors = target_size - sector_num; + if (nb_sectors <= 0) { + return 0; + } + if (nb_sectors > INT_MAX) { + nb_sectors = INT_MAX; + } + ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n); + if (ret & BDRV_BLOCK_ZERO) { + sector_num += n; + continue; + } + ret = bdrv_write_zeroes(bs, sector_num, n, flags); + if (ret < 0) { + error_report("error writing zeroes at sector %" PRId64 ": %s", + sector_num, strerror(-ret)); + return ret; + } + sector_num += n; + } } int bdrv_pread(BlockDriverState *bs, int64_t offset, @@ -2582,7 +2618,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, if (drv->bdrv_co_write_zeroes && buffer_is_zero(bounce_buffer, iov.iov_len)) { ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, - cluster_nb_sectors); + cluster_nb_sectors, 0); } else { /* This does not change the data on the disk, it is not necessary * to flush even in cache=writethrough mode. @@ -2715,32 +2751,65 @@ int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, BDRV_REQ_COPY_ON_READ); } +/* if no limit is specified in the BlockLimits use a default + * of 32768 512-byte sectors (16 MiB) per request. + */ +#define MAX_WRITE_ZEROES_DEFAULT 32768 + static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, - int64_t sector_num, int nb_sectors) + int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) { BlockDriver *drv = bs->drv; QEMUIOVector qiov; - struct iovec iov; - int ret; + struct iovec iov = {0}; + int ret = 0; - /* TODO Emulate only part of misaligned requests instead of letting block - * drivers return -ENOTSUP and emulate everything */ + int max_write_zeroes = bs->bl.max_write_zeroes ? + bs->bl.max_write_zeroes : MAX_WRITE_ZEROES_DEFAULT; - /* First try the efficient write zeroes operation */ - if (drv->bdrv_co_write_zeroes) { - ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors); - if (ret != -ENOTSUP) { - return ret; + while (nb_sectors > 0 && !ret) { + int num = nb_sectors; + + /* align request */ + if (bs->bl.write_zeroes_alignment && + num >= bs->bl.write_zeroes_alignment && + sector_num % bs->bl.write_zeroes_alignment) { + if (num > bs->bl.write_zeroes_alignment) { + num = bs->bl.write_zeroes_alignment; + } + num -= sector_num % bs->bl.write_zeroes_alignment; } - } - /* Fall back to bounce buffer if write zeroes is unsupported */ - iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE; - iov.iov_base = qemu_blockalign(bs, iov.iov_len); - memset(iov.iov_base, 0, iov.iov_len); - qemu_iovec_init_external(&qiov, &iov, 1); + /* limit request size */ + if (num > max_write_zeroes) { + num = max_write_zeroes; + } - ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, &qiov); + ret = -ENOTSUP; + /* First try the efficient write zeroes operation */ + if (drv->bdrv_co_write_zeroes) { + ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); + } + + if (ret == -ENOTSUP) { + /* Fall back to bounce buffer if write zeroes is unsupported */ + iov.iov_len = num * BDRV_SECTOR_SIZE; + if (iov.iov_base == NULL) { + /* allocate bounce buffer only once and ensure that it + * is big enough for this and all future requests. + */ + size_t bufsize = num <= nb_sectors ? num : max_write_zeroes; + iov.iov_base = qemu_blockalign(bs, bufsize * BDRV_SECTOR_SIZE); + memset(iov.iov_base, 0, bufsize * BDRV_SECTOR_SIZE); + } + qemu_iovec_init_external(&qiov, &iov, 1); + + ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); + } + + sector_num += num; + nb_sectors -= num; + } qemu_vfree(iov.iov_base); return ret; @@ -2783,7 +2852,7 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, if (ret < 0) { /* Do nothing, write notifier decided to fail this request */ } else if (flags & BDRV_REQ_ZERO_WRITE) { - ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors); + ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); } else { ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); } @@ -2792,9 +2861,7 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, ret = bdrv_co_flush(bs); } - if (bs->dirty_bitmap) { - bdrv_set_dirty(bs, sector_num, nb_sectors); - } + bdrv_set_dirty(bs, sector_num, nb_sectors); if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { bs->wr_highest_sector = sector_num + nb_sectors - 1; @@ -2817,12 +2884,17 @@ int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, } int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, - int64_t sector_num, int nb_sectors) + int64_t sector_num, int nb_sectors, + BdrvRequestFlags flags) { trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors); + if (!(bs->open_flags & BDRV_O_UNMAP)) { + flags &= ~BDRV_REQ_MAY_UNMAP; + } + return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, - BDRV_REQ_ZERO_WRITE); + BDRV_REQ_ZERO_WRITE | flags); } /** @@ -3102,6 +3174,36 @@ int bdrv_has_zero_init(BlockDriverState *bs) return 0; } +bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) +{ + BlockDriverInfo bdi; + + if (bs->backing_hd) { + return false; + } + + if (bdrv_get_info(bs, &bdi) == 0) { + return bdi.unallocated_blocks_are_zero; + } + + return false; +} + +bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) +{ + BlockDriverInfo bdi; + + if (bs->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) { + return false; + } + + if (bdrv_get_info(bs, &bdi) == 0) { + return bdi.can_write_zeroes_with_unmap; + } + + return false; +} + typedef struct BdrvCoGetBlockStatusData { BlockDriverState *bs; BlockDriverState *base; @@ -3171,8 +3273,8 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, *pnum, pnum); } - if (!(ret & BDRV_BLOCK_DATA)) { - if (bdrv_has_zero_init(bs)) { + if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) { + if (bdrv_unallocated_blocks_are_zero(bs)) { ret |= BDRV_BLOCK_ZERO; } else if (bs->backing_hd) { BlockDriverState *bs2 = bs->backing_hd; @@ -3330,7 +3432,7 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, if (bdrv_check_request(bs, sector_num, nb_sectors)) return -EIO; - assert(!bs->dirty_bitmap); + assert(QLIST_EMPTY(&bs->dirty_bitmaps)); return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); } @@ -3419,6 +3521,19 @@ int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, return -ENOTSUP; } +int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) +{ + while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { + bs = bs->file; + } + + if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { + return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); + } + + return -ENOTSUP; +} + int bdrv_debug_resume(BlockDriverState *bs, const char *tag) { while (bs && bs->drv && !bs->drv->bdrv_debug_resume) { @@ -4179,6 +4294,11 @@ static void coroutine_fn bdrv_discard_co_entry(void *opaque) rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); } +/* if no limit is specified in the BlockLimits use a default + * of 32768 512-byte sectors (16 MiB) per request. + */ +#define MAX_DISCARD_DEFAULT 32768 + int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { @@ -4190,9 +4310,7 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, return -EROFS; } - if (bs->dirty_bitmap) { - bdrv_reset_dirty(bs, sector_num, nb_sectors); - } + bdrv_reset_dirty(bs, sector_num, nb_sectors); /* Do nothing if disabled. */ if (!(bs->open_flags & BDRV_O_UNMAP)) { @@ -4200,7 +4318,37 @@ int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, } if (bs->drv->bdrv_co_discard) { - return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors); + int max_discard = bs->bl.max_discard ? + bs->bl.max_discard : MAX_DISCARD_DEFAULT; + + while (nb_sectors > 0) { + int ret; + int num = nb_sectors; + + /* align request */ + if (bs->bl.discard_alignment && + num >= bs->bl.discard_alignment && + sector_num % bs->bl.discard_alignment) { + if (num > bs->bl.discard_alignment) { + num = bs->bl.discard_alignment; + } + num -= sector_num % bs->bl.discard_alignment; + } + + /* limit request size */ + if (num > max_discard) { + num = max_discard; + } + + ret = bs->drv->bdrv_co_discard(bs, sector_num, num); + if (ret) { + return ret; + } + + sector_num += num; + nb_sectors -= num; + } + return 0; } else if (bs->drv->bdrv_aio_discard) { BlockDriverAIOCB *acb; CoroutineIOCompletion co = { @@ -4354,58 +4502,90 @@ bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) return true; } -void bdrv_set_dirty_tracking(BlockDriverState *bs, int granularity) +BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity) { int64_t bitmap_size; + BdrvDirtyBitmap *bitmap; assert((granularity & (granularity - 1)) == 0); - if (granularity) { - granularity >>= BDRV_SECTOR_BITS; - assert(!bs->dirty_bitmap); - bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS); - bs->dirty_bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1); - } else { - if (bs->dirty_bitmap) { - hbitmap_free(bs->dirty_bitmap); - bs->dirty_bitmap = NULL; + granularity >>= BDRV_SECTOR_BITS; + assert(granularity); + bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS); + bitmap = g_malloc0(sizeof(BdrvDirtyBitmap)); + bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1); + QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); + return bitmap; +} + +void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) +{ + BdrvDirtyBitmap *bm, *next; + QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { + if (bm == bitmap) { + QLIST_REMOVE(bitmap, list); + hbitmap_free(bitmap->bitmap); + g_free(bitmap); + return; } } } -int bdrv_get_dirty(BlockDriverState *bs, int64_t sector) +BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) +{ + BdrvDirtyBitmap *bm; + BlockDirtyInfoList *list = NULL; + BlockDirtyInfoList **plist = &list; + + QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { + BlockDirtyInfo *info = g_malloc0(sizeof(BlockDirtyInfo)); + BlockDirtyInfoList *entry = g_malloc0(sizeof(BlockDirtyInfoList)); + info->count = bdrv_get_dirty_count(bs, bm); + info->granularity = + ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap)); + entry->value = info; + *plist = entry; + plist = &entry->next; + } + + return list; +} + +int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector) { - if (bs->dirty_bitmap) { - return hbitmap_get(bs->dirty_bitmap, sector); + if (bitmap) { + return hbitmap_get(bitmap->bitmap, sector); } else { return 0; } } -void bdrv_dirty_iter_init(BlockDriverState *bs, HBitmapIter *hbi) +void bdrv_dirty_iter_init(BlockDriverState *bs, + BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) { - hbitmap_iter_init(hbi, bs->dirty_bitmap, 0); + hbitmap_iter_init(hbi, bitmap->bitmap, 0); } void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors) { - hbitmap_set(bs->dirty_bitmap, cur_sector, nr_sectors); + BdrvDirtyBitmap *bitmap; + QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { + hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); + } } -void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, - int nr_sectors) +void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors) { - hbitmap_reset(bs->dirty_bitmap, cur_sector, nr_sectors); + BdrvDirtyBitmap *bitmap; + QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { + hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); + } } -int64_t bdrv_get_dirty_count(BlockDriverState *bs) +int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) { - if (bs->dirty_bitmap) { - return hbitmap_count(bs->dirty_bitmap); - } else { - return 0; - } + return hbitmap_count(bitmap->bitmap); } /* Get a reference to bs */ |