diff options
Diffstat (limited to 'qemu/block/stream.c')
| -rw-r--r-- | qemu/block/stream.c | 246 |
1 files changed, 0 insertions, 246 deletions
diff --git a/qemu/block/stream.c b/qemu/block/stream.c deleted file mode 100644 index 332b9a183..000000000 --- a/qemu/block/stream.c +++ /dev/null @@ -1,246 +0,0 @@ -/* - * Image streaming - * - * Copyright IBM, Corp. 2011 - * - * Authors: - * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> - * - * This work is licensed under the terms of the GNU LGPL, version 2 or later. - * See the COPYING.LIB file in the top-level directory. - * - */ - -#include "qemu/osdep.h" -#include "trace.h" -#include "block/block_int.h" -#include "block/blockjob.h" -#include "qapi/error.h" -#include "qapi/qmp/qerror.h" -#include "qemu/ratelimit.h" -#include "sysemu/block-backend.h" - -enum { - /* - * Size of data buffer for populating the image file. This should be large - * enough to process multiple clusters in a single call, so that populating - * contiguous regions of the image is efficient. - */ - STREAM_BUFFER_SIZE = 512 * 1024, /* in bytes */ -}; - -#define SLICE_TIME 100000000ULL /* ns */ - -typedef struct StreamBlockJob { - BlockJob common; - RateLimit limit; - BlockDriverState *base; - BlockdevOnError on_error; - char *backing_file_str; -} StreamBlockJob; - -static int coroutine_fn stream_populate(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, - void *buf) -{ - struct iovec iov = { - .iov_base = buf, - .iov_len = nb_sectors * BDRV_SECTOR_SIZE, - }; - QEMUIOVector qiov; - - qemu_iovec_init_external(&qiov, &iov, 1); - - /* Copy-on-read the unallocated clusters */ - return bdrv_co_copy_on_readv(bs, sector_num, nb_sectors, &qiov); -} - -typedef struct { - int ret; - bool reached_end; -} StreamCompleteData; - -static void stream_complete(BlockJob *job, void *opaque) -{ - StreamBlockJob *s = container_of(job, StreamBlockJob, common); - StreamCompleteData *data = opaque; - BlockDriverState *base = s->base; - - if (!block_job_is_cancelled(&s->common) && data->reached_end && - data->ret == 0) { - const char *base_id = NULL, *base_fmt = NULL; - if (base) { - base_id = s->backing_file_str; - if (base->drv) { - base_fmt = base->drv->format_name; - } - } - data->ret = bdrv_change_backing_file(job->bs, base_id, base_fmt); - bdrv_set_backing_hd(job->bs, base); - } - - g_free(s->backing_file_str); - block_job_completed(&s->common, data->ret); - g_free(data); -} - -static void coroutine_fn stream_run(void *opaque) -{ - StreamBlockJob *s = opaque; - StreamCompleteData *data; - BlockDriverState *bs = s->common.bs; - BlockDriverState *base = s->base; - int64_t sector_num = 0; - int64_t end = -1; - int error = 0; - int ret = 0; - int n = 0; - void *buf; - - if (!bs->backing) { - goto out; - } - - s->common.len = bdrv_getlength(bs); - if (s->common.len < 0) { - ret = s->common.len; - goto out; - } - - end = s->common.len >> BDRV_SECTOR_BITS; - buf = qemu_blockalign(bs, STREAM_BUFFER_SIZE); - - /* Turn on copy-on-read for the whole block device so that guest read - * requests help us make progress. Only do this when copying the entire - * backing chain since the copy-on-read operation does not take base into - * account. - */ - if (!base) { - bdrv_enable_copy_on_read(bs); - } - - for (sector_num = 0; sector_num < end; sector_num += n) { - uint64_t delay_ns = 0; - bool copy; - -wait: - /* Note that even when no rate limit is applied we need to yield - * with no pending I/O here so that bdrv_drain_all() returns. - */ - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); - if (block_job_is_cancelled(&s->common)) { - break; - } - - copy = false; - - ret = bdrv_is_allocated(bs, sector_num, - STREAM_BUFFER_SIZE / BDRV_SECTOR_SIZE, &n); - if (ret == 1) { - /* Allocated in the top, no need to copy. */ - } else if (ret >= 0) { - /* Copy if allocated in the intermediate images. Limit to the - * known-unallocated area [sector_num, sector_num+n). */ - ret = bdrv_is_allocated_above(backing_bs(bs), base, - sector_num, n, &n); - - /* Finish early if end of backing file has been reached */ - if (ret == 0 && n == 0) { - n = end - sector_num; - } - - copy = (ret == 1); - } - trace_stream_one_iteration(s, sector_num, n, ret); - if (copy) { - if (s->common.speed) { - delay_ns = ratelimit_calculate_delay(&s->limit, n); - if (delay_ns > 0) { - goto wait; - } - } - ret = stream_populate(bs, sector_num, n, buf); - } - if (ret < 0) { - BlockErrorAction action = - block_job_error_action(&s->common, s->common.bs, s->on_error, - true, -ret); - if (action == BLOCK_ERROR_ACTION_STOP) { - n = 0; - continue; - } - if (error == 0) { - error = ret; - } - if (action == BLOCK_ERROR_ACTION_REPORT) { - break; - } - } - ret = 0; - - /* Publish progress */ - s->common.offset += n * BDRV_SECTOR_SIZE; - } - - if (!base) { - bdrv_disable_copy_on_read(bs); - } - - /* Do not remove the backing file if an error was there but ignored. */ - ret = error; - - qemu_vfree(buf); - -out: - /* Modify backing chain and close BDSes in main loop */ - data = g_malloc(sizeof(*data)); - data->ret = ret; - data->reached_end = sector_num == end; - block_job_defer_to_main_loop(&s->common, stream_complete, data); -} - -static void stream_set_speed(BlockJob *job, int64_t speed, Error **errp) -{ - StreamBlockJob *s = container_of(job, StreamBlockJob, common); - - if (speed < 0) { - error_setg(errp, QERR_INVALID_PARAMETER, "speed"); - return; - } - ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); -} - -static const BlockJobDriver stream_job_driver = { - .instance_size = sizeof(StreamBlockJob), - .job_type = BLOCK_JOB_TYPE_STREAM, - .set_speed = stream_set_speed, -}; - -void stream_start(BlockDriverState *bs, BlockDriverState *base, - const char *backing_file_str, int64_t speed, - BlockdevOnError on_error, - BlockCompletionFunc *cb, - void *opaque, Error **errp) -{ - StreamBlockJob *s; - - if ((on_error == BLOCKDEV_ON_ERROR_STOP || - on_error == BLOCKDEV_ON_ERROR_ENOSPC) && - (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) { - error_setg(errp, QERR_INVALID_PARAMETER, "on-error"); - return; - } - - s = block_job_create(&stream_job_driver, bs, speed, cb, opaque, errp); - if (!s) { - return; - } - - s->base = base; - s->backing_file_str = g_strdup(backing_file_str); - - s->on_error = on_error; - s->common.co = qemu_coroutine_create(stream_run); - trace_stream_start(bs, base, s, s->common.co, opaque); - qemu_coroutine_enter(s->common.co, s); -} |