1097 lines
36 KiB
C
1097 lines
36 KiB
C
/*
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* Image mirroring
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*
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* Copyright Red Hat, Inc. 2012
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*
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* Authors:
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* Paolo Bonzini <pbonzini@redhat.com>
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*
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* This work is licensed under the terms of the GNU LGPL, version 2 or later.
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* See the COPYING.LIB file in the top-level directory.
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*
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*/
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#include "qemu/osdep.h"
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#include "trace.h"
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#include "block/blockjob.h"
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#include "block/block_int.h"
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#include "sysemu/block-backend.h"
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#include "qapi/error.h"
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#include "qapi/qmp/qerror.h"
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#include "qemu/ratelimit.h"
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#include "qemu/bitmap.h"
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#define SLICE_TIME 100000000ULL /* ns */
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#define MAX_IN_FLIGHT 16
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#define MAX_IO_SECTORS ((1 << 20) >> BDRV_SECTOR_BITS) /* 1 Mb */
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#define DEFAULT_MIRROR_BUF_SIZE \
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(MAX_IN_FLIGHT * MAX_IO_SECTORS * BDRV_SECTOR_SIZE)
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/* The mirroring buffer is a list of granularity-sized chunks.
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* Free chunks are organized in a list.
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*/
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typedef struct MirrorBuffer {
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QSIMPLEQ_ENTRY(MirrorBuffer) next;
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} MirrorBuffer;
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typedef struct MirrorBlockJob {
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BlockJob common;
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RateLimit limit;
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BlockBackend *target;
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BlockDriverState *base;
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/* The name of the graph node to replace */
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char *replaces;
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/* The BDS to replace */
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BlockDriverState *to_replace;
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/* Used to block operations on the drive-mirror-replace target */
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Error *replace_blocker;
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bool is_none_mode;
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BlockMirrorBackingMode backing_mode;
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BlockdevOnError on_source_error, on_target_error;
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bool synced;
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bool should_complete;
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int64_t granularity;
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size_t buf_size;
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int64_t bdev_length;
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unsigned long *cow_bitmap;
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BdrvDirtyBitmap *dirty_bitmap;
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BdrvDirtyBitmapIter *dbi;
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uint8_t *buf;
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QSIMPLEQ_HEAD(, MirrorBuffer) buf_free;
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int buf_free_count;
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uint64_t last_pause_ns;
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unsigned long *in_flight_bitmap;
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int in_flight;
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int64_t sectors_in_flight;
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int ret;
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bool unmap;
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bool waiting_for_io;
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int target_cluster_sectors;
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int max_iov;
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} MirrorBlockJob;
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typedef struct MirrorOp {
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MirrorBlockJob *s;
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QEMUIOVector qiov;
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int64_t sector_num;
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int nb_sectors;
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} MirrorOp;
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static BlockErrorAction mirror_error_action(MirrorBlockJob *s, bool read,
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int error)
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{
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s->synced = false;
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if (read) {
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return block_job_error_action(&s->common, s->on_source_error,
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true, error);
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} else {
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return block_job_error_action(&s->common, s->on_target_error,
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false, error);
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}
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}
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static void mirror_iteration_done(MirrorOp *op, int ret)
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{
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MirrorBlockJob *s = op->s;
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struct iovec *iov;
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int64_t chunk_num;
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int i, nb_chunks, sectors_per_chunk;
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trace_mirror_iteration_done(s, op->sector_num, op->nb_sectors, ret);
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s->in_flight--;
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s->sectors_in_flight -= op->nb_sectors;
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iov = op->qiov.iov;
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for (i = 0; i < op->qiov.niov; i++) {
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MirrorBuffer *buf = (MirrorBuffer *) iov[i].iov_base;
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QSIMPLEQ_INSERT_TAIL(&s->buf_free, buf, next);
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s->buf_free_count++;
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}
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sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS;
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chunk_num = op->sector_num / sectors_per_chunk;
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nb_chunks = DIV_ROUND_UP(op->nb_sectors, sectors_per_chunk);
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bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks);
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if (ret >= 0) {
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if (s->cow_bitmap) {
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bitmap_set(s->cow_bitmap, chunk_num, nb_chunks);
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}
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s->common.offset += (uint64_t)op->nb_sectors * BDRV_SECTOR_SIZE;
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}
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qemu_iovec_destroy(&op->qiov);
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g_free(op);
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if (s->waiting_for_io) {
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qemu_coroutine_enter(s->common.co);
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}
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}
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static void mirror_write_complete(void *opaque, int ret)
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{
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MirrorOp *op = opaque;
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MirrorBlockJob *s = op->s;
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if (ret < 0) {
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BlockErrorAction action;
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bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors);
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action = mirror_error_action(s, false, -ret);
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if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
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s->ret = ret;
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}
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}
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mirror_iteration_done(op, ret);
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}
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static void mirror_read_complete(void *opaque, int ret)
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{
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MirrorOp *op = opaque;
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MirrorBlockJob *s = op->s;
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if (ret < 0) {
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BlockErrorAction action;
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bdrv_set_dirty_bitmap(s->dirty_bitmap, op->sector_num, op->nb_sectors);
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action = mirror_error_action(s, true, -ret);
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if (action == BLOCK_ERROR_ACTION_REPORT && s->ret >= 0) {
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s->ret = ret;
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}
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mirror_iteration_done(op, ret);
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return;
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}
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blk_aio_pwritev(s->target, op->sector_num * BDRV_SECTOR_SIZE, &op->qiov,
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0, mirror_write_complete, op);
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}
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static inline void mirror_clip_sectors(MirrorBlockJob *s,
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int64_t sector_num,
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int *nb_sectors)
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{
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*nb_sectors = MIN(*nb_sectors,
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s->bdev_length / BDRV_SECTOR_SIZE - sector_num);
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}
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/* Round sector_num and/or nb_sectors to target cluster if COW is needed, and
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* return the offset of the adjusted tail sector against original. */
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static int mirror_cow_align(MirrorBlockJob *s,
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int64_t *sector_num,
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int *nb_sectors)
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{
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bool need_cow;
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int ret = 0;
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int chunk_sectors = s->granularity >> BDRV_SECTOR_BITS;
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int64_t align_sector_num = *sector_num;
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int align_nb_sectors = *nb_sectors;
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int max_sectors = chunk_sectors * s->max_iov;
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need_cow = !test_bit(*sector_num / chunk_sectors, s->cow_bitmap);
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need_cow |= !test_bit((*sector_num + *nb_sectors - 1) / chunk_sectors,
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s->cow_bitmap);
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if (need_cow) {
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bdrv_round_sectors_to_clusters(blk_bs(s->target), *sector_num,
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*nb_sectors, &align_sector_num,
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&align_nb_sectors);
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}
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if (align_nb_sectors > max_sectors) {
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align_nb_sectors = max_sectors;
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if (need_cow) {
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align_nb_sectors = QEMU_ALIGN_DOWN(align_nb_sectors,
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s->target_cluster_sectors);
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}
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}
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/* Clipping may result in align_nb_sectors unaligned to chunk boundary, but
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* that doesn't matter because it's already the end of source image. */
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mirror_clip_sectors(s, align_sector_num, &align_nb_sectors);
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ret = align_sector_num + align_nb_sectors - (*sector_num + *nb_sectors);
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*sector_num = align_sector_num;
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*nb_sectors = align_nb_sectors;
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assert(ret >= 0);
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return ret;
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}
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static inline void mirror_wait_for_io(MirrorBlockJob *s)
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{
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assert(!s->waiting_for_io);
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s->waiting_for_io = true;
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qemu_coroutine_yield();
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s->waiting_for_io = false;
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}
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/* Submit async read while handling COW.
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* Returns: The number of sectors copied after and including sector_num,
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* excluding any sectors copied prior to sector_num due to alignment.
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* This will be nb_sectors if no alignment is necessary, or
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* (new_end - sector_num) if tail is rounded up or down due to
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* alignment or buffer limit.
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*/
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static int mirror_do_read(MirrorBlockJob *s, int64_t sector_num,
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int nb_sectors)
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{
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BlockBackend *source = s->common.blk;
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int sectors_per_chunk, nb_chunks;
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int ret;
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MirrorOp *op;
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int max_sectors;
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sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS;
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max_sectors = sectors_per_chunk * s->max_iov;
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/* We can only handle as much as buf_size at a time. */
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nb_sectors = MIN(s->buf_size >> BDRV_SECTOR_BITS, nb_sectors);
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nb_sectors = MIN(max_sectors, nb_sectors);
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assert(nb_sectors);
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ret = nb_sectors;
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if (s->cow_bitmap) {
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ret += mirror_cow_align(s, §or_num, &nb_sectors);
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}
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assert(nb_sectors << BDRV_SECTOR_BITS <= s->buf_size);
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/* The sector range must meet granularity because:
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* 1) Caller passes in aligned values;
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* 2) mirror_cow_align is used only when target cluster is larger. */
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assert(!(sector_num % sectors_per_chunk));
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nb_chunks = DIV_ROUND_UP(nb_sectors, sectors_per_chunk);
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while (s->buf_free_count < nb_chunks) {
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trace_mirror_yield_in_flight(s, sector_num, s->in_flight);
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mirror_wait_for_io(s);
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}
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/* Allocate a MirrorOp that is used as an AIO callback. */
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op = g_new(MirrorOp, 1);
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op->s = s;
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op->sector_num = sector_num;
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op->nb_sectors = nb_sectors;
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/* Now make a QEMUIOVector taking enough granularity-sized chunks
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* from s->buf_free.
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*/
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qemu_iovec_init(&op->qiov, nb_chunks);
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while (nb_chunks-- > 0) {
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MirrorBuffer *buf = QSIMPLEQ_FIRST(&s->buf_free);
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size_t remaining = nb_sectors * BDRV_SECTOR_SIZE - op->qiov.size;
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QSIMPLEQ_REMOVE_HEAD(&s->buf_free, next);
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s->buf_free_count--;
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qemu_iovec_add(&op->qiov, buf, MIN(s->granularity, remaining));
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}
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/* Copy the dirty cluster. */
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s->in_flight++;
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s->sectors_in_flight += nb_sectors;
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trace_mirror_one_iteration(s, sector_num, nb_sectors);
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blk_aio_preadv(source, sector_num * BDRV_SECTOR_SIZE, &op->qiov, 0,
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mirror_read_complete, op);
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return ret;
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}
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static void mirror_do_zero_or_discard(MirrorBlockJob *s,
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int64_t sector_num,
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int nb_sectors,
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bool is_discard)
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{
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MirrorOp *op;
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/* Allocate a MirrorOp that is used as an AIO callback. The qiov is zeroed
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* so the freeing in mirror_iteration_done is nop. */
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op = g_new0(MirrorOp, 1);
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op->s = s;
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op->sector_num = sector_num;
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op->nb_sectors = nb_sectors;
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s->in_flight++;
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s->sectors_in_flight += nb_sectors;
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if (is_discard) {
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blk_aio_pdiscard(s->target, sector_num << BDRV_SECTOR_BITS,
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op->nb_sectors << BDRV_SECTOR_BITS,
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mirror_write_complete, op);
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} else {
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blk_aio_pwrite_zeroes(s->target, sector_num * BDRV_SECTOR_SIZE,
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op->nb_sectors * BDRV_SECTOR_SIZE,
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s->unmap ? BDRV_REQ_MAY_UNMAP : 0,
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mirror_write_complete, op);
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}
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}
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static uint64_t coroutine_fn mirror_iteration(MirrorBlockJob *s)
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{
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BlockDriverState *source = blk_bs(s->common.blk);
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int64_t sector_num, first_chunk;
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uint64_t delay_ns = 0;
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/* At least the first dirty chunk is mirrored in one iteration. */
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int nb_chunks = 1;
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int64_t end = s->bdev_length / BDRV_SECTOR_SIZE;
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int sectors_per_chunk = s->granularity >> BDRV_SECTOR_BITS;
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bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target));
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int max_io_sectors = MAX((s->buf_size >> BDRV_SECTOR_BITS) / MAX_IN_FLIGHT,
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MAX_IO_SECTORS);
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sector_num = bdrv_dirty_iter_next(s->dbi);
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if (sector_num < 0) {
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bdrv_set_dirty_iter(s->dbi, 0);
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sector_num = bdrv_dirty_iter_next(s->dbi);
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trace_mirror_restart_iter(s, bdrv_get_dirty_count(s->dirty_bitmap));
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assert(sector_num >= 0);
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}
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first_chunk = sector_num / sectors_per_chunk;
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while (test_bit(first_chunk, s->in_flight_bitmap)) {
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trace_mirror_yield_in_flight(s, sector_num, s->in_flight);
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mirror_wait_for_io(s);
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}
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block_job_pause_point(&s->common);
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/* Find the number of consective dirty chunks following the first dirty
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* one, and wait for in flight requests in them. */
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while (nb_chunks * sectors_per_chunk < (s->buf_size >> BDRV_SECTOR_BITS)) {
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int64_t next_dirty;
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int64_t next_sector = sector_num + nb_chunks * sectors_per_chunk;
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int64_t next_chunk = next_sector / sectors_per_chunk;
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if (next_sector >= end ||
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!bdrv_get_dirty(source, s->dirty_bitmap, next_sector)) {
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break;
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}
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if (test_bit(next_chunk, s->in_flight_bitmap)) {
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break;
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}
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next_dirty = bdrv_dirty_iter_next(s->dbi);
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if (next_dirty > next_sector || next_dirty < 0) {
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/* The bitmap iterator's cache is stale, refresh it */
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bdrv_set_dirty_iter(s->dbi, next_sector);
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next_dirty = bdrv_dirty_iter_next(s->dbi);
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}
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assert(next_dirty == next_sector);
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nb_chunks++;
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}
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/* Clear dirty bits before querying the block status, because
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* calling bdrv_get_block_status_above could yield - if some blocks are
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* marked dirty in this window, we need to know.
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*/
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bdrv_reset_dirty_bitmap(s->dirty_bitmap, sector_num,
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nb_chunks * sectors_per_chunk);
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bitmap_set(s->in_flight_bitmap, sector_num / sectors_per_chunk, nb_chunks);
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while (nb_chunks > 0 && sector_num < end) {
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int ret;
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int io_sectors, io_sectors_acct;
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BlockDriverState *file;
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enum MirrorMethod {
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MIRROR_METHOD_COPY,
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MIRROR_METHOD_ZERO,
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MIRROR_METHOD_DISCARD
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} mirror_method = MIRROR_METHOD_COPY;
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assert(!(sector_num % sectors_per_chunk));
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ret = bdrv_get_block_status_above(source, NULL, sector_num,
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nb_chunks * sectors_per_chunk,
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&io_sectors, &file);
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if (ret < 0) {
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io_sectors = MIN(nb_chunks * sectors_per_chunk, max_io_sectors);
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} else if (ret & BDRV_BLOCK_DATA) {
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io_sectors = MIN(io_sectors, max_io_sectors);
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}
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io_sectors -= io_sectors % sectors_per_chunk;
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if (io_sectors < sectors_per_chunk) {
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io_sectors = sectors_per_chunk;
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} else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) {
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int64_t target_sector_num;
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int target_nb_sectors;
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bdrv_round_sectors_to_clusters(blk_bs(s->target), sector_num,
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io_sectors, &target_sector_num,
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&target_nb_sectors);
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if (target_sector_num == sector_num &&
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target_nb_sectors == io_sectors) {
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mirror_method = ret & BDRV_BLOCK_ZERO ?
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MIRROR_METHOD_ZERO :
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MIRROR_METHOD_DISCARD;
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}
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}
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while (s->in_flight >= MAX_IN_FLIGHT) {
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trace_mirror_yield_in_flight(s, sector_num, s->in_flight);
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mirror_wait_for_io(s);
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}
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if (s->ret < 0) {
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return 0;
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}
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mirror_clip_sectors(s, sector_num, &io_sectors);
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switch (mirror_method) {
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case MIRROR_METHOD_COPY:
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io_sectors = mirror_do_read(s, sector_num, io_sectors);
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io_sectors_acct = io_sectors;
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break;
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case MIRROR_METHOD_ZERO:
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case MIRROR_METHOD_DISCARD:
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mirror_do_zero_or_discard(s, sector_num, io_sectors,
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mirror_method == MIRROR_METHOD_DISCARD);
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if (write_zeroes_ok) {
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io_sectors_acct = 0;
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} else {
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io_sectors_acct = io_sectors;
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}
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break;
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default:
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abort();
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}
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assert(io_sectors);
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sector_num += io_sectors;
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nb_chunks -= DIV_ROUND_UP(io_sectors, sectors_per_chunk);
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if (s->common.speed) {
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delay_ns = ratelimit_calculate_delay(&s->limit, io_sectors_acct);
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}
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}
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return delay_ns;
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}
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|
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static void mirror_free_init(MirrorBlockJob *s)
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{
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int granularity = s->granularity;
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size_t buf_size = s->buf_size;
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uint8_t *buf = s->buf;
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assert(s->buf_free_count == 0);
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QSIMPLEQ_INIT(&s->buf_free);
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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;
|
|
}
|
|
}
|
|
|
|
/* This is also used for the .pause callback. There is no matching
|
|
* mirror_resume() because mirror_run() will begin iterating again
|
|
* when the job is resumed.
|
|
*/
|
|
static void mirror_wait_for_all_io(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 = blk_bs(s->common.blk);
|
|
BlockDriverState *target_bs = blk_bs(s->target);
|
|
|
|
/* 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 = src;
|
|
if (s->to_replace) {
|
|
to_replace = s->to_replace;
|
|
}
|
|
|
|
if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) {
|
|
bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL);
|
|
}
|
|
|
|
/* The mirror job has no requests in flight any more, but we need to
|
|
* drain potential other users of the BDS before changing the graph. */
|
|
bdrv_drained_begin(target_bs);
|
|
bdrv_replace_in_backing_chain(to_replace, target_bs);
|
|
bdrv_drained_end(target_bs);
|
|
|
|
/* We just changed the BDS the job BB refers to */
|
|
blk_remove_bs(job->blk);
|
|
blk_insert_bs(job->blk, src);
|
|
}
|
|
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);
|
|
blk_unref(s->target);
|
|
s->target = NULL;
|
|
block_job_completed(&s->common, data->ret);
|
|
g_free(data);
|
|
bdrv_drained_end(src);
|
|
bdrv_unref(src);
|
|
}
|
|
|
|
static void mirror_throttle(MirrorBlockJob *s)
|
|
{
|
|
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
|
|
|
|
if (now - s->last_pause_ns > SLICE_TIME) {
|
|
s->last_pause_ns = now;
|
|
block_job_sleep_ns(&s->common, QEMU_CLOCK_REALTIME, 0);
|
|
} else {
|
|
block_job_pause_point(&s->common);
|
|
}
|
|
}
|
|
|
|
static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
|
|
{
|
|
int64_t sector_num, end;
|
|
BlockDriverState *base = s->base;
|
|
BlockDriverState *bs = blk_bs(s->common.blk);
|
|
BlockDriverState *target_bs = blk_bs(s->target);
|
|
int ret, n;
|
|
|
|
end = s->bdev_length / BDRV_SECTOR_SIZE;
|
|
|
|
if (base == NULL && !bdrv_has_zero_init(target_bs)) {
|
|
if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
|
|
bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, end);
|
|
return 0;
|
|
}
|
|
|
|
for (sector_num = 0; sector_num < end; ) {
|
|
int nb_sectors = MIN(end - sector_num,
|
|
QEMU_ALIGN_DOWN(INT_MAX, s->granularity) >> BDRV_SECTOR_BITS);
|
|
|
|
mirror_throttle(s);
|
|
|
|
if (block_job_is_cancelled(&s->common)) {
|
|
return 0;
|
|
}
|
|
|
|
if (s->in_flight >= MAX_IN_FLIGHT) {
|
|
trace_mirror_yield(s, s->in_flight, s->buf_free_count, -1);
|
|
mirror_wait_for_io(s);
|
|
continue;
|
|
}
|
|
|
|
mirror_do_zero_or_discard(s, sector_num, nb_sectors, false);
|
|
sector_num += nb_sectors;
|
|
}
|
|
|
|
mirror_wait_for_all_io(s);
|
|
}
|
|
|
|
/* First part, loop on the sectors and initialize the dirty bitmap. */
|
|
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);
|
|
|
|
mirror_throttle(s);
|
|
|
|
if (block_job_is_cancelled(&s->common)) {
|
|
return 0;
|
|
}
|
|
|
|
ret = bdrv_is_allocated_above(bs, base, sector_num, nb_sectors, &n);
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
assert(n > 0);
|
|
if (ret == 1) {
|
|
bdrv_set_dirty_bitmap(s->dirty_bitmap, sector_num, n);
|
|
}
|
|
sector_num += n;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void coroutine_fn mirror_run(void *opaque)
|
|
{
|
|
MirrorBlockJob *s = opaque;
|
|
MirrorExitData *data;
|
|
BlockDriverState *bs = blk_bs(s->common.blk);
|
|
BlockDriverState *target_bs = blk_bs(s->target);
|
|
bool need_drain = true;
|
|
int64_t length;
|
|
BlockDriverInfo bdi;
|
|
char backing_filename[2]; /* we only need 2 characters because we are only
|
|
checking for a NULL string */
|
|
int ret = 0;
|
|
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(target_bs, backing_filename,
|
|
sizeof(backing_filename));
|
|
if (!bdrv_get_info(target_bs, &bdi) && bdi.cluster_size) {
|
|
target_cluster_size = bdi.cluster_size;
|
|
}
|
|
if (backing_filename[0] && !target_bs->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(bs->bl.max_iov, target_bs->bl.max_iov);
|
|
|
|
s->buf = qemu_try_blockalign(bs, s->buf_size);
|
|
if (s->buf == NULL) {
|
|
ret = -ENOMEM;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
mirror_free_init(s);
|
|
|
|
s->last_pause_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
|
|
if (!s->is_none_mode) {
|
|
ret = mirror_dirty_init(s);
|
|
if (ret < 0 || block_job_is_cancelled(&s->common)) {
|
|
goto immediate_exit;
|
|
}
|
|
}
|
|
|
|
assert(!s->dbi);
|
|
s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap, 0);
|
|
for (;;) {
|
|
uint64_t delay_ns = 0;
|
|
int64_t cnt, delta;
|
|
bool should_complete;
|
|
|
|
if (s->ret < 0) {
|
|
ret = s->ret;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
block_job_pause_point(&s->common);
|
|
|
|
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.
|
|
*/
|
|
delta = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) - s->last_pause_ns;
|
|
if (delta < 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 = blk_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, so pause it now. Before deciding
|
|
* whether to switch to target check one last time if I/O has
|
|
* come in the meanwhile, and if not flush the data to disk.
|
|
*/
|
|
trace_mirror_before_drain(s, cnt);
|
|
|
|
bdrv_drained_begin(bs);
|
|
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
|
|
if (cnt > 0) {
|
|
bdrv_drained_end(bs);
|
|
continue;
|
|
}
|
|
|
|
/* The two disks are in sync. Exit and report successful
|
|
* completion.
|
|
*/
|
|
assert(QLIST_EMPTY(&bs->tracked_requests));
|
|
s->common.cancelled = false;
|
|
need_drain = false;
|
|
break;
|
|
}
|
|
|
|
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);
|
|
}
|
|
s->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)));
|
|
assert(need_drain);
|
|
mirror_wait_for_all_io(s);
|
|
}
|
|
|
|
assert(s->in_flight == 0);
|
|
qemu_vfree(s->buf);
|
|
g_free(s->cow_bitmap);
|
|
g_free(s->in_flight_bitmap);
|
|
bdrv_dirty_iter_free(s->dbi);
|
|
bdrv_release_dirty_bitmap(bs, s->dirty_bitmap);
|
|
|
|
data = g_malloc(sizeof(*data));
|
|
data->ret = ret;
|
|
|
|
if (need_drain) {
|
|
bdrv_drained_begin(bs);
|
|
}
|
|
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_complete(BlockJob *job, Error **errp)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
|
|
BlockDriverState *src, *target;
|
|
|
|
src = blk_bs(job->blk);
|
|
target = blk_bs(s->target);
|
|
|
|
if (!s->synced) {
|
|
error_setg(errp, "The active block job '%s' cannot be completed",
|
|
job->id);
|
|
return;
|
|
}
|
|
|
|
if (s->backing_mode == MIRROR_OPEN_BACKING_CHAIN) {
|
|
int ret;
|
|
|
|
assert(!target->backing);
|
|
ret = bdrv_open_backing_file(target, NULL, "backing", errp);
|
|
if (ret < 0) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* block all operations on to_replace bs */
|
|
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);
|
|
}
|
|
|
|
if (s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
|
|
BlockDriverState *backing = s->is_none_mode ? src : s->base;
|
|
if (backing_bs(target) != backing) {
|
|
bdrv_set_backing_hd(target, backing);
|
|
}
|
|
}
|
|
|
|
s->should_complete = true;
|
|
block_job_enter(&s->common);
|
|
}
|
|
|
|
static void mirror_pause(BlockJob *job)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
|
|
|
|
mirror_wait_for_all_io(s);
|
|
}
|
|
|
|
static void mirror_attached_aio_context(BlockJob *job, AioContext *new_context)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
|
|
|
|
blk_set_aio_context(s->target, new_context);
|
|
}
|
|
|
|
static void mirror_drain(BlockJob *job)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
|
|
|
|
/* Need to keep a reference in case blk_drain triggers execution
|
|
* of mirror_complete...
|
|
*/
|
|
if (s->target) {
|
|
BlockBackend *target = s->target;
|
|
blk_ref(target);
|
|
blk_drain(target);
|
|
blk_unref(target);
|
|
}
|
|
}
|
|
|
|
static const BlockJobDriver mirror_job_driver = {
|
|
.instance_size = sizeof(MirrorBlockJob),
|
|
.job_type = BLOCK_JOB_TYPE_MIRROR,
|
|
.set_speed = mirror_set_speed,
|
|
.complete = mirror_complete,
|
|
.pause = mirror_pause,
|
|
.attached_aio_context = mirror_attached_aio_context,
|
|
.drain = mirror_drain,
|
|
};
|
|
|
|
static const BlockJobDriver commit_active_job_driver = {
|
|
.instance_size = sizeof(MirrorBlockJob),
|
|
.job_type = BLOCK_JOB_TYPE_COMMIT,
|
|
.set_speed = mirror_set_speed,
|
|
.complete = mirror_complete,
|
|
.pause = mirror_pause,
|
|
.attached_aio_context = mirror_attached_aio_context,
|
|
.drain = mirror_drain,
|
|
};
|
|
|
|
static void mirror_start_job(const char *job_id, BlockDriverState *bs,
|
|
int creation_flags, BlockDriverState *target,
|
|
const char *replaces, int64_t speed,
|
|
uint32_t granularity, int64_t buf_size,
|
|
BlockMirrorBackingMode backing_mode,
|
|
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,
|
|
bool auto_complete)
|
|
{
|
|
MirrorBlockJob *s;
|
|
|
|
if (granularity == 0) {
|
|
granularity = bdrv_get_default_bitmap_granularity(target);
|
|
}
|
|
|
|
assert ((granularity & (granularity - 1)) == 0);
|
|
|
|
if (buf_size < 0) {
|
|
error_setg(errp, "Invalid parameter 'buf-size'");
|
|
return;
|
|
}
|
|
|
|
if (buf_size == 0) {
|
|
buf_size = DEFAULT_MIRROR_BUF_SIZE;
|
|
}
|
|
|
|
s = block_job_create(job_id, driver, bs, speed, creation_flags,
|
|
cb, opaque, errp);
|
|
if (!s) {
|
|
return;
|
|
}
|
|
|
|
s->target = blk_new();
|
|
blk_insert_bs(s->target, target);
|
|
|
|
s->replaces = g_strdup(replaces);
|
|
s->on_source_error = on_source_error;
|
|
s->on_target_error = on_target_error;
|
|
s->is_none_mode = is_none_mode;
|
|
s->backing_mode = backing_mode;
|
|
s->base = base;
|
|
s->granularity = granularity;
|
|
s->buf_size = ROUND_UP(buf_size, granularity);
|
|
s->unmap = unmap;
|
|
if (auto_complete) {
|
|
s->should_complete = true;
|
|
}
|
|
|
|
s->dirty_bitmap = bdrv_create_dirty_bitmap(bs, granularity, NULL, errp);
|
|
if (!s->dirty_bitmap) {
|
|
g_free(s->replaces);
|
|
blk_unref(s->target);
|
|
block_job_unref(&s->common);
|
|
return;
|
|
}
|
|
|
|
block_job_add_bdrv(&s->common, target);
|
|
/* In commit_active_start() all intermediate nodes disappear, so
|
|
* any jobs in them must be blocked */
|
|
if (bdrv_chain_contains(bs, target)) {
|
|
BlockDriverState *iter;
|
|
for (iter = backing_bs(bs); iter != target; iter = backing_bs(iter)) {
|
|
block_job_add_bdrv(&s->common, iter);
|
|
}
|
|
}
|
|
|
|
s->common.co = qemu_coroutine_create(mirror_run, s);
|
|
trace_mirror_start(bs, s, s->common.co, opaque);
|
|
qemu_coroutine_enter(s->common.co);
|
|
}
|
|
|
|
void mirror_start(const char *job_id, BlockDriverState *bs,
|
|
BlockDriverState *target, const char *replaces,
|
|
int64_t speed, uint32_t granularity, int64_t buf_size,
|
|
MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
|
|
BlockdevOnError on_source_error,
|
|
BlockdevOnError on_target_error,
|
|
bool unmap, 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(job_id, bs, BLOCK_JOB_DEFAULT, target, replaces,
|
|
speed, granularity, buf_size, backing_mode,
|
|
on_source_error, on_target_error, unmap, NULL, NULL, errp,
|
|
&mirror_job_driver, is_none_mode, base, false);
|
|
}
|
|
|
|
void commit_active_start(const char *job_id, BlockDriverState *bs,
|
|
BlockDriverState *base, int creation_flags,
|
|
int64_t speed, BlockdevOnError on_error,
|
|
BlockCompletionFunc *cb, void *opaque, Error **errp,
|
|
bool auto_complete)
|
|
{
|
|
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;
|
|
}
|
|
}
|
|
|
|
mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0,
|
|
MIRROR_LEAVE_BACKING_CHAIN,
|
|
on_error, on_error, true, cb, opaque, &local_err,
|
|
&commit_active_job_driver, false, base, auto_complete);
|
|
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;
|
|
}
|