diff options
Diffstat (limited to 'qemu/block/mirror.c')
| -rw-r--r-- | qemu/block/mirror.c | 976 |
1 files changed, 0 insertions, 976 deletions
diff --git a/qemu/block/mirror.c b/qemu/block/mirror.c deleted file mode 100644 index 039f48125..000000000 --- a/qemu/block/mirror.c +++ /dev/null @@ -1,976 +0,0 @@ -/* - * Image mirroring - * - * Copyright Red Hat, Inc. 2012 - * - * Authors: - * Paolo Bonzini <pbonzini@redhat.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/blockjob.h" -#include "block/block_int.h" -#include "sysemu/block-backend.h" -#include "qapi/error.h" -#include "qapi/qmp/qerror.h" -#include "qemu/ratelimit.h" -#include "qemu/bitmap.h" -#include "qemu/error-report.h" - -#define SLICE_TIME 100000000ULL /* ns */ -#define MAX_IN_FLIGHT 16 -#define DEFAULT_MIRROR_BUF_SIZE (10 << 20) - -/* The mirroring buffer is a list of granularity-sized chunks. - * Free chunks are organized in a list. - */ -typedef struct MirrorBuffer { - QSIMPLEQ_ENTRY(MirrorBuffer) next; -} MirrorBuffer; - -typedef struct MirrorBlockJob { - BlockJob common; - RateLimit limit; - BlockDriverState *target; - BlockDriverState *base; - /* The name of the graph node to replace */ - char *replaces; - /* The BDS to replace */ - BlockDriverState *to_replace; - /* Used to block operations on the drive-mirror-replace target */ - Error *replace_blocker; - bool is_none_mode; - BlockdevOnError on_source_error, on_target_error; - bool synced; - bool should_complete; - int64_t granularity; - size_t buf_size; - int64_t bdev_length; - unsigned long *cow_bitmap; - BdrvDirtyBitmap *dirty_bitmap; - HBitmapIter hbi; - uint8_t *buf; - QSIMPLEQ_HEAD(, MirrorBuffer) buf_free; - int buf_free_count; - - unsigned long *in_flight_bitmap; - int in_flight; - int sectors_in_flight; - int ret; - bool unmap; - bool waiting_for_io; - int target_cluster_sectors; - int max_iov; -} MirrorBlockJob; - -typedef struct MirrorOp { - MirrorBlockJob *s; - QEMUIOVector qiov; - int64_t sector_num; - int nb_sectors; -} MirrorOp; - -static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read, - int error) -{ - s->synced = false; - if (read) { - return block_job_error_action(&s->common, s->common.bs, - s->on_source_error, true, error); - } else { - return block_job_error_action(&s->common, s->target, - s->on_target_error, false, error); - } -} - -static void mirror_iteration_done(MirrorOp *op, int ret) -{ - MirrorBlockJob *s = op->s; - struct iovec *iov; - int64_t chunk_num; - int i, nb_chunks, sectors_per_chunk; - - trace_mirror_iteration_done(s, op->sector_num, op->nb_sectors, ret); - - s->in_flight--; - s->sectors_in_flight -= op->nb_sectors; - iov = op->qiov.iov; - for (i = 0; i < op->qiov.niov; i++) { - MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base; - QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next); - s->buf_free_count++; - } - - sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; - chunk_num = op->sector_num / sectors_per_chunk; - nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk); - bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks); - if (ret >= 0) { - if (s->cow_bitmap) { - bitmap_set(s->cow_bitmap, chunk_num, nb_chunks); - } - s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE; - } - - qemu_iovec_destroy(&op->qiov); - g_free(op); - - if (s->waiting_for_io) { - qemu_coroutine_enter(s->common.co, NULL); - } -} - -static void mirror_write_complete(void *opaque, int ret) -{ - MirrorOp *op = opaque; - MirrorBlockJob *s = op->s; - if (ret < 0) { - BlockErrorAction action; - - bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); - action = mirror_error_action(s, false, -ret); - if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { - s->ret = ret; - } - } - mirror_iteration_done(op, ret); -} - -static void mirror_read_complete(void *opaque, int ret) -{ - MirrorOp *op = opaque; - MirrorBlockJob *s = op->s; - if (ret < 0) { - BlockErrorAction action; - - bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors); - action = mirror_error_action(s, true, -ret); - if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) { - s->ret = ret; - } - - mirror_iteration_done(op, ret); - return; - } - bdrv_aio_writev(s->target, op->sector_num, &op->qiov, op->nb_sectors, - mirror_write_complete, op); -} - -static inline void mirror_clip_sectors(MirrorBlockJob *s, - int64_t sector_num, - int *nb_sectors) -{ - *nb_sectors = MIN(*nb_sectors, - s->bdev_length / BDRV_SECTOR_SIZE - sector_num); -} - -/* Round sector_num and/or nb_sectors to target cluster if COW is needed, and - * return the offset of the adjusted tail sector against original. */ -static int mirror_cow_align(MirrorBlockJob *s, - int64_t *sector_num, - int *nb_sectors) -{ - bool need_cow; - int ret = 0; - int chunk_sectors = s->granularity >> BDRV_SECTOR_BITS; - int64_t align_sector_num = *sector_num; - int align_nb_sectors = *nb_sectors; - int max_sectors = chunk_sectors * s->max_iov; - - need_cow = !test_bit(*sector_num / chunk_sectors, s->cow_bitmap); - need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors, - s->cow_bitmap); - if (need_cow) { - bdrv_round_to_clusters(s->target, *sector_num, *nb_sectors, - &align_sector_num, &align_nb_sectors); - } - - if (align_nb_sectors > max_sectors) { - align_nb_sectors = max_sectors; - if (need_cow) { - align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors, - s->target_cluster_sectors); - } - } - /* Clipping may result in align_nb_sectors unaligned to chunk boundary, but - * that doesn't matter because it's already the end of source image. */ - mirror_clip_sectors(s, align_sector_num, &align_nb_sectors); - - ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors); - *sector_num = align_sector_num; - *nb_sectors = align_nb_sectors; - assert(ret >= 0); - return ret; -} - -static inline void mirror_wait_for_io(MirrorBlockJob *s) -{ - assert(!s->waiting_for_io); - s->waiting_for_io = true; - qemu_coroutine_yield(); - s->waiting_for_io = false; -} - -/* Submit async read while handling COW. - * Returns: nb_sectors if no alignment is necessary, or - * (new_end - sector_num) if tail is rounded up or down due to - * alignment or buffer limit. - */ -static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num, - int nb_sectors) -{ - BlockDriverState *source = s->common.bs; - int sectors_per_chunk, nb_chunks; - int ret = nb_sectors; - MirrorOp *op; - - sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; - - /* We can only handle as much as buf_size at a time. */ - nb_sectors = MIN(s->buf_size >> BDRV_SECTOR_BITS, nb_sectors); - assert(nb_sectors); - - if (s->cow_bitmap) { - ret += mirror_cow_align(s, §or_num, &nb_sectors); - } - assert(nb_sectors << BDRV_SECTOR_BITS <= s->buf_size); - /* The sector range must meet granularity because: - * 1) Caller passes in aligned values; - * 2) mirror_cow_align is used only when target cluster is larger. */ - assert(!(sector_num % sectors_per_chunk)); - nb_chunks = DIV_ROUND_UP(nb_sectors, sectors_per_chunk); - - while (s->buf_free_count < nb_chunks) { - trace_mirror_yield_in_flight(s, sector_num, s->in_flight); - mirror_wait_for_io(s); - } - - /* Allocate a MirrorOp that is used as an AIO callback. */ - op = g_new(MirrorOp, 1); - op->s = s; - op->sector_num = sector_num; - op->nb_sectors = nb_sectors; - - /* Now make a QEMUIOVector taking enough granularity-sized chunks - * from s->buf_free. - */ - qemu_iovec_init(&op->qiov, nb_chunks); - while (nb_chunks-- > 0) { - MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free); - size_t remaining = nb_sectors * BDRV_SECTOR_SIZE - op->qiov.size; - - QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next); - s->buf_free_count--; - qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining)); - } - - /* Copy the dirty cluster. */ - s->in_flight++; - s->sectors_in_flight += nb_sectors; - trace_mirror_one_iteration(s, sector_num, nb_sectors); - - bdrv_aio_readv(source, sector_num, &op->qiov, nb_sectors, - mirror_read_complete, op); - return ret; -} - -static void mirror_do_zero_or_discard(MirrorBlockJob *s, - int64_t sector_num, - int nb_sectors, - bool is_discard) -{ - MirrorOp *op; - - /* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed - * so the freeing in mirror_iteration_done is nop. */ - op = g_new0(MirrorOp, 1); - op->s = s; - op->sector_num = sector_num; - op->nb_sectors = nb_sectors; - - s->in_flight++; - s->sectors_in_flight += nb_sectors; - if (is_discard) { - bdrv_aio_discard(s->target, sector_num, op->nb_sectors, - mirror_write_complete, op); - } else { - bdrv_aio_write_zeroes(s->target, sector_num, op->nb_sectors, - s->unmap ? BDRV_REQ_MAY_UNMAP : 0, - mirror_write_complete, op); - } -} - -static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s) -{ - BlockDriverState *source = s->common.bs; - int64_t sector_num, first_chunk; - uint64_t delay_ns = 0; - /* At least the first dirty chunk is mirrored in one iteration. */ - int nb_chunks = 1; - int64_t end = s->bdev_length / BDRV_SECTOR_SIZE; - int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS; - - sector_num = hbitmap_iter_next(&s->hbi); - if (sector_num < 0) { - bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi); - sector_num = hbitmap_iter_next(&s->hbi); - trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap)); - assert(sector_num >= 0); - } - - first_chunk = sector_num / sectors_per_chunk; - while (test_bit(first_chunk, s->in_flight_bitmap)) { - trace_mirror_yield_in_flight(s, first_chunk, s->in_flight); - mirror_wait_for_io(s); - } - - /* Find the number of consective dirty chunks following the first dirty - * one, and wait for in flight requests in them. */ - while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) { - int64_t hbitmap_next; - int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk; - int64_t next_chunk = next_sector / sectors_per_chunk; - if (next_sector >= end || - !bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) { - break; - } - if (test_bit(next_chunk, s->in_flight_bitmap)) { - break; - } - - hbitmap_next = hbitmap_iter_next(&s->hbi); - if (hbitmap_next > next_sector || hbitmap_next < 0) { - /* The bitmap iterator's cache is stale, refresh it */ - bdrv_set_dirty_iter(&s->hbi, next_sector); - hbitmap_next = hbitmap_iter_next(&s->hbi); - } - assert(hbitmap_next == next_sector); - nb_chunks++; - } - - /* Clear dirty bits before querying the block status, because - * calling bdrv_get_block_status_above could yield - if some blocks are - * marked dirty in this window, we need to know. - */ - bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num, - nb_chunks * sectors_per_chunk); - bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks); - while (nb_chunks > 0 && sector_num < end) { - int ret; - int io_sectors; - BlockDriverState *file; - enum MirrorMethod { - MIRROR_METHOD_COPY, - MIRROR_METHOD_ZERO, - MIRROR_METHOD_DISCARD - } mirror_method = MIRROR_METHOD_COPY; - - assert(!(sector_num % sectors_per_chunk)); - ret = bdrv_get_block_status_above(source, NULL, sector_num, - nb_chunks * sectors_per_chunk, - &io_sectors, &file); - if (ret < 0) { - io_sectors = nb_chunks * sectors_per_chunk; - } - - io_sectors -= io_sectors % sectors_per_chunk; - if (io_sectors < sectors_per_chunk) { - io_sectors = sectors_per_chunk; - } else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) { - int64_t target_sector_num; - int target_nb_sectors; - bdrv_round_to_clusters(s->target, sector_num, io_sectors, - &target_sector_num, &target_nb_sectors); - if (target_sector_num == sector_num && - target_nb_sectors == io_sectors) { - mirror_method = ret & BDRV_BLOCK_ZERO ? - MIRROR_METHOD_ZERO : - MIRROR_METHOD_DISCARD; - } - } - - mirror_clip_sectors(s, sector_num, &io_sectors); - switch (mirror_method) { - case MIRROR_METHOD_COPY: - io_sectors = mirror_do_read(s, sector_num, io_sectors); - break; - case MIRROR_METHOD_ZERO: - mirror_do_zero_or_discard(s, sector_num, io_sectors, false); - break; - case MIRROR_METHOD_DISCARD: - mirror_do_zero_or_discard(s, sector_num, io_sectors, true); - break; - default: - abort(); - } - assert(io_sectors); - sector_num += io_sectors; - nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk); - delay_ns += ratelimit_calculate_delay(&s->limit, io_sectors); - } - return delay_ns; -} - -static void mirror_free_init(MirrorBlockJob *s) -{ - int granularity = s->granularity; - size_t buf_size = s->buf_size; - uint8_t *buf = s->buf; - - assert(s->buf_free_count == 0); - QSIMPLEQ_INIT(&s->buf_free); - while (buf_size != 0) { - MirrorBuffer *cur = (MirrorBuffer *)buf; - QSIMPLEQ_INSERT_TAIL(&s->buf_free, cur, next); - s->buf_free_count++; - buf_size -= granularity; - buf += granularity; - } -} - -static void mirror_drain(MirrorBlockJob *s) -{ - while (s->in_flight > 0) { - mirror_wait_for_io(s); - } -} - -typedef struct { - int ret; -} MirrorExitData; - -static void mirror_exit(BlockJob *job, void *opaque) -{ - MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); - MirrorExitData *data = opaque; - AioContext *replace_aio_context = NULL; - BlockDriverState *src = s->common.bs; - - /* Make sure that the source BDS doesn't go away before we called - * block_job_completed(). */ - bdrv_ref(src); - - if (s->to_replace) { - replace_aio_context = bdrv_get_aio_context(s->to_replace); - aio_context_acquire(replace_aio_context); - } - - if (s->should_complete && data->ret == 0) { - BlockDriverState *to_replace = s->common.bs; - if (s->to_replace) { - to_replace = s->to_replace; - } - - /* This was checked in mirror_start_job(), but meanwhile one of the - * nodes could have been newly attached to a BlockBackend. */ - if (to_replace->blk && s->target->blk) { - error_report("block job: Can't create node with two BlockBackends"); - data->ret = -EINVAL; - goto out; - } - - if (bdrv_get_flags(s->target) != bdrv_get_flags(to_replace)) { - bdrv_reopen(s->target, bdrv_get_flags(to_replace), NULL); - } - bdrv_replace_in_backing_chain(to_replace, s->target); - } - -out: - if (s->to_replace) { - bdrv_op_unblock_all(s->to_replace, s->replace_blocker); - error_free(s->replace_blocker); - bdrv_unref(s->to_replace); - } - if (replace_aio_context) { - aio_context_release(replace_aio_context); - } - g_free(s->replaces); - bdrv_op_unblock_all(s->target, s->common.blocker); - bdrv_unref(s->target); - block_job_completed(&s->common, data->ret); - g_free(data); - bdrv_drained_end(src); - if (qemu_get_aio_context() == bdrv_get_aio_context(src)) { - aio_enable_external(iohandler_get_aio_context()); - } - bdrv_unref(src); -} - -static void coroutine_fn mirror_run(void *opaque) -{ - MirrorBlockJob *s = opaque; - MirrorExitData *data; - BlockDriverState *bs = s->common.bs; - int64_t sector_num, end, length; - uint64_t last_pause_ns; - BlockDriverInfo bdi; - char backing_filename[2]; /* we only need 2 characters because we are only - checking for a NULL string */ - int ret = 0; - int n; - int target_cluster_size = BDRV_SECTOR_SIZE; - - if (block_job_is_cancelled(&s->common)) { - goto immediate_exit; - } - - s->bdev_length = bdrv_getlength(bs); - if (s->bdev_length < 0) { - ret = s->bdev_length; - goto immediate_exit; - } else if (s->bdev_length == 0) { - /* Report BLOCK_JOB_READY and wait for complete. */ - block_job_event_ready(&s->common); - s->synced = true; - while (!block_job_is_cancelled(&s->common) && !s->should_complete) { - block_job_yield(&s->common); - } - s->common.cancelled = false; - goto immediate_exit; - } - - length = DIV_ROUND_UP(s->bdev_length, s->granularity); - s->in_flight_bitmap = bitmap_new(length); - - /* If we have no backing file yet in the destination, we cannot let - * the destination do COW. Instead, we copy sectors around the - * dirty data if needed. We need a bitmap to do that. - */ - bdrv_get_backing_filename(s->target, backing_filename, - sizeof(backing_filename)); - if (!bdrv_get_info(s->target, &bdi) && bdi.cluster_size) { - target_cluster_size = bdi.cluster_size; - } - if (backing_filename[0] && !s->target->backing - && s->granularity < target_cluster_size) { - s->buf_size = MAX(s->buf_size, target_cluster_size); - s->cow_bitmap = bitmap_new(length); - } - s->target_cluster_sectors = target_cluster_size >> BDRV_SECTOR_BITS; - s->max_iov = MIN(s->common.bs->bl.max_iov, s->target->bl.max_iov); - - end = s->bdev_length / BDRV_SECTOR_SIZE; - s->buf = qemu_try_blockalign(bs, s->buf_size); - if (s->buf == NULL) { - ret = -ENOMEM; - goto immediate_exit; - } - - mirror_free_init(s); - - last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); - if (!s->is_none_mode) { - /* First part, loop on the sectors and initialize the dirty bitmap. */ - BlockDriverState *base = s->base; - bool mark_all_dirty = s->base == NULL && !bdrv_has_zero_init(s->target); - - for (sector_num = 0; sector_num < end; ) { - /* Just to make sure we are not exceeding int limit. */ - int nb_sectors = MIN(INT_MAX >> BDRV_SECTOR_BITS, - end - sector_num); - int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); - - if (now - last_pause_ns > SLICE_TIME) { - last_pause_ns = now; - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0); - } - - if (block_job_is_cancelled(&s->common)) { - goto immediate_exit; - } - - ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n); - - if (ret < 0) { - goto immediate_exit; - } - - assert(n > 0); - if (ret == 1 || mark_all_dirty) { - bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n); - } - sector_num += n; - } - } - - bdrv_dirty_iter_init(s->dirty_bitmap, &s->hbi); - for (;;) { - uint64_t delay_ns = 0; - int64_t cnt; - bool should_complete; - - if (s->ret < 0) { - ret = s->ret; - goto immediate_exit; - } - - cnt = bdrv_get_dirty_count(s->dirty_bitmap); - /* s->common.offset contains the number of bytes already processed so - * far, cnt is the number of dirty sectors remaining and - * s->sectors_in_flight is the number of sectors currently being - * processed; together those are the current total operation length */ - s->common.len = s->common.offset + - (cnt + s->sectors_in_flight) * BDRV_SECTOR_SIZE; - - /* Note that even when no rate limit is applied we need to yield - * periodically with no pending I/O so that bdrv_drain_all() returns. - * We do so every SLICE_TIME nanoseconds, or when there is an error, - * or when the source is clean, whichever comes first. - */ - if (qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - last_pause_ns < SLICE_TIME && - s->common.iostatus == BLOCK_DEVICE_IO_STATUS_OK) { - if (s->in_flight == MAX_IN_FLIGHT || s->buf_free_count == 0 || - (cnt == 0 && s->in_flight > 0)) { - trace_mirror_yield(s, s->in_flight, s->buf_free_count, cnt); - mirror_wait_for_io(s); - continue; - } else if (cnt != 0) { - delay_ns = mirror_iteration(s); - } - } - - should_complete = false; - if (s->in_flight == 0 && cnt == 0) { - trace_mirror_before_flush(s); - ret = bdrv_flush(s->target); - if (ret < 0) { - if (mirror_error_action(s, false, -ret) == - BLOCK_ERROR_ACTION_REPORT) { - goto immediate_exit; - } - } else { - /* We're out of the streaming phase. From now on, if the job - * is cancelled we will actually complete all pending I/O and - * report completion. This way, block-job-cancel will leave - * the target in a consistent state. - */ - if (!s->synced) { - block_job_event_ready(&s->common); - s->synced = true; - } - - should_complete = s->should_complete || - block_job_is_cancelled(&s->common); - cnt = bdrv_get_dirty_count(s->dirty_bitmap); - } - } - - if (cnt == 0 && should_complete) { - /* The dirty bitmap is not updated while operations are pending. - * If we're about to exit, wait for pending operations before - * calling bdrv_get_dirty_count(bs), or we may exit while the - * source has dirty data to copy! - * - * Note that I/O can be submitted by the guest while - * mirror_populate runs. - */ - trace_mirror_before_drain(s, cnt); - bdrv_co_drain(bs); - cnt = bdrv_get_dirty_count(s->dirty_bitmap); - } - - ret = 0; - trace_mirror_before_sleep(s, cnt, s->synced, delay_ns); - if (!s->synced) { - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); - if (block_job_is_cancelled(&s->common)) { - break; - } - } else if (!should_complete) { - delay_ns = (s->in_flight == 0 && cnt == 0 ? SLICE_TIME : 0); - block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, delay_ns); - } else if (cnt == 0) { - /* The two disks are in sync. Exit and report successful - * completion. - */ - assert(QLIST_EMPTY(&bs->tracked_requests)); - s->common.cancelled = false; - break; - } - last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); - } - -immediate_exit: - if (s->in_flight > 0) { - /* We get here only if something went wrong. Either the job failed, - * or it was cancelled prematurely so that we do not guarantee that - * the target is a copy of the source. - */ - assert(ret < 0 || (!s->synced && block_job_is_cancelled(&s->common))); - mirror_drain(s); - } - - assert(s->in_flight == 0); - qemu_vfree(s->buf); - g_free(s->cow_bitmap); - g_free(s->in_flight_bitmap); - bdrv_release_dirty_bitmap(bs, s->dirty_bitmap); - if (s->target->blk) { - blk_iostatus_disable(s->target->blk); - } - - data = g_malloc(sizeof(*data)); - data->ret = ret; - /* Before we switch to target in mirror_exit, make sure data doesn't - * change. */ - bdrv_drained_begin(s->common.bs); - if (qemu_get_aio_context() == bdrv_get_aio_context(bs)) { - /* FIXME: virtio host notifiers run on iohandler_ctx, therefore the - * above bdrv_drained_end isn't enough to quiesce it. This is ugly, we - * need a block layer API change to achieve this. */ - aio_disable_external(iohandler_get_aio_context()); - } - block_job_defer_to_main_loop(&s->common, mirror_exit, data); -} - -static void mirror_set_speed(BlockJob *job, int64_t speed, Error **errp) -{ - MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); - - if (speed < 0) { - error_setg(errp, QERR_INVALID_PARAMETER, "speed"); - return; - } - ratelimit_set_speed(&s->limit, speed / BDRV_SECTOR_SIZE, SLICE_TIME); -} - -static void mirror_iostatus_reset(BlockJob *job) -{ - MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); - - if (s->target->blk) { - blk_iostatus_reset(s->target->blk); - } -} - -static void mirror_complete(BlockJob *job, Error **errp) -{ - MirrorBlockJob *s = container_of(job, MirrorBlockJob, common); - Error *local_err = NULL; - int ret; - - ret = bdrv_open_backing_file(s->target, NULL, "backing", &local_err); - if (ret < 0) { - error_propagate(errp, local_err); - return; - } - if (!s->synced) { - error_setg(errp, QERR_BLOCK_JOB_NOT_READY, job->id); - return; - } - - /* check the target bs is not blocked and block all operations on it */ - if (s->replaces) { - AioContext *replace_aio_context; - - s->to_replace = bdrv_find_node(s->replaces); - if (!s->to_replace) { - error_setg(errp, "Node name '%s' not found", s->replaces); - return; - } - - replace_aio_context = bdrv_get_aio_context(s->to_replace); - aio_context_acquire(replace_aio_context); - - error_setg(&s->replace_blocker, - "block device is in use by block-job-complete"); - bdrv_op_block_all(s->to_replace, s->replace_blocker); - bdrv_ref(s->to_replace); - - aio_context_release(replace_aio_context); - } - - s->should_complete = true; - block_job_enter(&s->common); -} - -static const BlockJobDriver mirror_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_MIRROR, - .set_speed = mirror_set_speed, - .iostatus_reset= mirror_iostatus_reset, - .complete = mirror_complete, -}; - -static const BlockJobDriver commit_active_job_driver = { - .instance_size = sizeof(MirrorBlockJob), - .job_type = BLOCK_JOB_TYPE_COMMIT, - .set_speed = mirror_set_speed, - .iostatus_reset - = mirror_iostatus_reset, - .complete = mirror_complete, -}; - -static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target, - const char *replaces, - int64_t speed, uint32_t granularity, - int64_t buf_size, - BlockdevOnError on_source_error, - BlockdevOnError on_target_error, - bool unmap, - BlockCompletionFunc *cb, - void *opaque, Error **errp, - const BlockJobDriver *driver, - bool is_none_mode, BlockDriverState *base) -{ - MirrorBlockJob *s; - BlockDriverState *replaced_bs; - - if (granularity == 0) { - granularity = bdrv_get_default_bitmap_granularity(target); - } - - assert ((granularity & (granularity - 1)) == 0); - - if ((on_source_error == BLOCKDEV_ON_ERROR_STOP || - on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) && - (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) { - error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error"); - return; - } - - if (buf_size < 0) { - error_setg(errp, "Invalid parameter 'buf-size'"); - return; - } - - if (buf_size == 0) { - buf_size = DEFAULT_MIRROR_BUF_SIZE; - } - - /* We can't support this case as long as the block layer can't handle - * multiple BlockBackends per BlockDriverState. */ - if (replaces) { - replaced_bs = bdrv_lookup_bs(replaces, replaces, errp); - if (replaced_bs == NULL) { - return; - } - } else { - replaced_bs = bs; - } - if (replaced_bs->blk && target->blk) { - error_setg(errp, "Can't create node with two BlockBackends"); - return; - } - - s = block_job_create(driver, bs, speed, cb, opaque, errp); - if (!s) { - return; - } - - s->replaces = g_strdup(replaces); - s->on_source_error = on_source_error; - s->on_target_error = on_target_error; - s->target = target; - s->is_none_mode = is_none_mode; - s->base = base; - s->granularity = granularity; - s->buf_size = ROUND_UP(buf_size, granularity); - s->unmap = unmap; - - s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp); - if (!s->dirty_bitmap) { - g_free(s->replaces); - block_job_unref(&s->common); - return; - } - - bdrv_op_block_all(s->target, s->common.blocker); - - if (s->target->blk) { - blk_set_on_error(s->target->blk, on_target_error, on_target_error); - blk_iostatus_enable(s->target->blk); - } - s->common.co = qemu_coroutine_create(mirror_run); - trace_mirror_start(bs, s, s->common.co, opaque); - qemu_coroutine_enter(s->common.co, s); -} - -void mirror_start(BlockDriverState *bs, BlockDriverState *target, - const char *replaces, - int64_t speed, uint32_t granularity, int64_t buf_size, - MirrorSyncMode mode, BlockdevOnError on_source_error, - BlockdevOnError on_target_error, - bool unmap, - BlockCompletionFunc *cb, - void *opaque, Error **errp) -{ - bool is_none_mode; - BlockDriverState *base; - - if (mode == MIRROR_SYNC_MODE_INCREMENTAL) { - error_setg(errp, "Sync mode 'incremental' not supported"); - return; - } - is_none_mode = mode == MIRROR_SYNC_MODE_NONE; - base = mode == MIRROR_SYNC_MODE_TOP ? backing_bs(bs) : NULL; - mirror_start_job(bs, target, replaces, - speed, granularity, buf_size, - on_source_error, on_target_error, unmap, cb, opaque, errp, - &mirror_job_driver, is_none_mode, base); -} - -void commit_active_start(BlockDriverState *bs, BlockDriverState *base, - int64_t speed, - BlockdevOnError on_error, - BlockCompletionFunc *cb, - void *opaque, Error **errp) -{ - int64_t length, base_length; - int orig_base_flags; - int ret; - Error *local_err = NULL; - - orig_base_flags = bdrv_get_flags(base); - - if (bdrv_reopen(base, bs->open_flags, errp)) { - return; - } - - length = bdrv_getlength(bs); - if (length < 0) { - error_setg_errno(errp, -length, - "Unable to determine length of %s", bs->filename); - goto error_restore_flags; - } - - base_length = bdrv_getlength(base); - if (base_length < 0) { - error_setg_errno(errp, -base_length, - "Unable to determine length of %s", base->filename); - goto error_restore_flags; - } - - if (length > base_length) { - ret = bdrv_truncate(base, length); - if (ret < 0) { - error_setg_errno(errp, -ret, - "Top image %s is larger than base image %s, and " - "resize of base image failed", - bs->filename, base->filename); - goto error_restore_flags; - } - } - - bdrv_ref(base); - mirror_start_job(bs, base, NULL, speed, 0, 0, - on_error, on_error, false, cb, opaque, &local_err, - &commit_active_job_driver, false, base); - if (local_err) { - error_propagate(errp, local_err); - goto error_restore_flags; - } - - return; - -error_restore_flags: - /* ignore error and errp for bdrv_reopen, because we want to propagate - * the original error */ - bdrv_reopen(base, orig_base_flags, NULL); - return; -} |