mirror of https://github.com/proxmox/mirror_qemu
1979 lines
65 KiB
C
1979 lines
65 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 "qemu/cutils.h"
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#include "qemu/coroutine.h"
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#include "qemu/range.h"
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#include "trace.h"
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#include "block/blockjob_int.h"
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#include "block/block_int.h"
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#include "block/dirty-bitmap.h"
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#include "sysemu/block-backend.h"
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#include "qapi/error.h"
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#include "qemu/ratelimit.h"
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#include "qemu/bitmap.h"
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#include "qemu/memalign.h"
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#define MAX_IN_FLIGHT 16
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#define MAX_IO_BYTES (1 << 20) /* 1 Mb */
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#define DEFAULT_MIRROR_BUF_SIZE (MAX_IN_FLIGHT * MAX_IO_BYTES)
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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 MirrorOp MirrorOp;
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typedef struct MirrorBlockJob {
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BlockJob common;
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BlockBackend *target;
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BlockDriverState *mirror_top_bs;
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BlockDriverState *base;
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BlockDriverState *base_overlay;
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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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/* Whether the target image requires explicit zero-initialization */
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bool zero_target;
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MirrorCopyMode copy_mode;
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BlockdevOnError on_source_error, on_target_error;
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/* Set when the target is synced (dirty bitmap is clean, nothing
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* in flight) and the job is running in active mode */
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bool actively_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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unsigned in_flight;
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int64_t bytes_in_flight;
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QTAILQ_HEAD(, MirrorOp) ops_in_flight;
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int ret;
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bool unmap;
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int target_cluster_size;
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int max_iov;
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bool initial_zeroing_ongoing;
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int in_active_write_counter;
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int64_t active_write_bytes_in_flight;
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bool prepared;
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bool in_drain;
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} MirrorBlockJob;
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typedef struct MirrorBDSOpaque {
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MirrorBlockJob *job;
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bool stop;
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bool is_commit;
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} MirrorBDSOpaque;
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struct MirrorOp {
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MirrorBlockJob *s;
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QEMUIOVector qiov;
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int64_t offset;
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uint64_t bytes;
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/* The pointee is set by mirror_co_read(), mirror_co_zero(), and
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* mirror_co_discard() before yielding for the first time */
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int64_t *bytes_handled;
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bool is_pseudo_op;
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bool is_active_write;
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bool is_in_flight;
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CoQueue waiting_requests;
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Coroutine *co;
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MirrorOp *waiting_for_op;
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QTAILQ_ENTRY(MirrorOp) next;
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};
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typedef 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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} MirrorMethod;
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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->actively_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 coroutine_fn mirror_wait_on_conflicts(MirrorOp *self,
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MirrorBlockJob *s,
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uint64_t offset,
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uint64_t bytes)
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{
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uint64_t self_start_chunk = offset / s->granularity;
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uint64_t self_end_chunk = DIV_ROUND_UP(offset + bytes, s->granularity);
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uint64_t self_nb_chunks = self_end_chunk - self_start_chunk;
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while (find_next_bit(s->in_flight_bitmap, self_end_chunk,
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self_start_chunk) < self_end_chunk &&
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s->ret >= 0)
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{
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MirrorOp *op;
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QTAILQ_FOREACH(op, &s->ops_in_flight, next) {
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uint64_t op_start_chunk = op->offset / s->granularity;
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uint64_t op_nb_chunks = DIV_ROUND_UP(op->offset + op->bytes,
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s->granularity) -
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op_start_chunk;
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if (op == self) {
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continue;
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}
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if (ranges_overlap(self_start_chunk, self_nb_chunks,
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op_start_chunk, op_nb_chunks))
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{
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if (self) {
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/*
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* If the operation is already (indirectly) waiting for us,
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* or will wait for us as soon as it wakes up, then just go
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* on (instead of producing a deadlock in the former case).
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*/
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if (op->waiting_for_op) {
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continue;
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}
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self->waiting_for_op = op;
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}
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qemu_co_queue_wait(&op->waiting_requests, NULL);
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if (self) {
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self->waiting_for_op = NULL;
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}
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break;
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}
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}
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}
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}
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static void coroutine_fn 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;
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trace_mirror_iteration_done(s, op->offset, op->bytes, ret);
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s->in_flight--;
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s->bytes_in_flight -= op->bytes;
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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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chunk_num = op->offset / s->granularity;
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nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity);
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bitmap_clear(s->in_flight_bitmap, chunk_num, nb_chunks);
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QTAILQ_REMOVE(&s->ops_in_flight, op, next);
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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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if (!s->initial_zeroing_ongoing) {
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job_progress_update(&s->common.job, op->bytes);
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}
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}
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qemu_iovec_destroy(&op->qiov);
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qemu_co_queue_restart_all(&op->waiting_requests);
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g_free(op);
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}
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static void coroutine_fn mirror_write_complete(MirrorOp *op, int ret)
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{
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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->offset, op->bytes);
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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 coroutine_fn mirror_read_complete(MirrorOp *op, int ret)
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{
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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->offset, op->bytes);
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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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ret = blk_co_pwritev(s->target, op->offset, op->qiov.size, &op->qiov, 0);
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mirror_write_complete(op, ret);
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}
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/* Clip bytes relative to offset to not exceed end-of-file */
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static inline int64_t mirror_clip_bytes(MirrorBlockJob *s,
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int64_t offset,
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int64_t bytes)
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{
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return MIN(bytes, s->bdev_length - offset);
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}
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/* Round offset and/or bytes to target cluster if COW is needed, and
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* return the offset of the adjusted tail against original. */
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static int mirror_cow_align(MirrorBlockJob *s, int64_t *offset,
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uint64_t *bytes)
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{
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bool need_cow;
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int ret = 0;
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int64_t align_offset = *offset;
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int64_t align_bytes = *bytes;
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int max_bytes = s->granularity * s->max_iov;
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need_cow = !test_bit(*offset / s->granularity, s->cow_bitmap);
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need_cow |= !test_bit((*offset + *bytes - 1) / s->granularity,
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s->cow_bitmap);
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if (need_cow) {
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bdrv_round_to_clusters(blk_bs(s->target), *offset, *bytes,
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&align_offset, &align_bytes);
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}
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if (align_bytes > max_bytes) {
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align_bytes = max_bytes;
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if (need_cow) {
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align_bytes = QEMU_ALIGN_DOWN(align_bytes, s->target_cluster_size);
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}
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}
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/* Clipping may result in align_bytes 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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align_bytes = mirror_clip_bytes(s, align_offset, align_bytes);
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ret = align_offset + align_bytes - (*offset + *bytes);
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*offset = align_offset;
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*bytes = align_bytes;
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assert(ret >= 0);
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return ret;
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}
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static inline void coroutine_fn
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mirror_wait_for_free_in_flight_slot(MirrorBlockJob *s)
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{
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MirrorOp *op;
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QTAILQ_FOREACH(op, &s->ops_in_flight, next) {
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/*
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* Do not wait on pseudo ops, because it may in turn wait on
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* some other operation to start, which may in fact be the
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* caller of this function. Since there is only one pseudo op
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* at any given time, we will always find some real operation
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* to wait on.
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* Also, do not wait on active operations, because they do not
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* use up in-flight slots.
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*/
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if (!op->is_pseudo_op && op->is_in_flight && !op->is_active_write) {
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qemu_co_queue_wait(&op->waiting_requests, NULL);
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return;
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}
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}
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abort();
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}
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/* Perform a mirror copy operation.
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*
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* *op->bytes_handled is set to the number of bytes copied after and
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* including offset, excluding any bytes copied prior to offset due
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* to alignment. This will be op->bytes if no alignment is necessary,
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* or (new_end - op->offset) if the 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 void coroutine_fn mirror_co_read(void *opaque)
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{
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MirrorOp *op = opaque;
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MirrorBlockJob *s = op->s;
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int nb_chunks;
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uint64_t ret;
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uint64_t max_bytes;
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max_bytes = s->granularity * s->max_iov;
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/* We can only handle as much as buf_size at a time. */
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op->bytes = MIN(s->buf_size, MIN(max_bytes, op->bytes));
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assert(op->bytes);
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assert(op->bytes < BDRV_REQUEST_MAX_BYTES);
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*op->bytes_handled = op->bytes;
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if (s->cow_bitmap) {
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*op->bytes_handled += mirror_cow_align(s, &op->offset, &op->bytes);
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}
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/* Cannot exceed BDRV_REQUEST_MAX_BYTES + INT_MAX */
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assert(*op->bytes_handled <= UINT_MAX);
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assert(op->bytes <= s->buf_size);
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/* The offset is granularity-aligned 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(QEMU_IS_ALIGNED(op->offset, s->granularity));
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/* The range is sector-aligned, since bdrv_getlength() rounds up. */
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assert(QEMU_IS_ALIGNED(op->bytes, BDRV_SECTOR_SIZE));
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nb_chunks = DIV_ROUND_UP(op->bytes, s->granularity);
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while (s->buf_free_count < nb_chunks) {
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trace_mirror_yield_in_flight(s, op->offset, s->in_flight);
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mirror_wait_for_free_in_flight_slot(s);
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}
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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 = op->bytes - 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->bytes_in_flight += op->bytes;
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op->is_in_flight = true;
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trace_mirror_one_iteration(s, op->offset, op->bytes);
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WITH_GRAPH_RDLOCK_GUARD() {
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ret = bdrv_co_preadv(s->mirror_top_bs->backing, op->offset, op->bytes,
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&op->qiov, 0);
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}
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mirror_read_complete(op, ret);
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}
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static void coroutine_fn mirror_co_zero(void *opaque)
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{
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MirrorOp *op = opaque;
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int ret;
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op->s->in_flight++;
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op->s->bytes_in_flight += op->bytes;
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*op->bytes_handled = op->bytes;
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op->is_in_flight = true;
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ret = blk_co_pwrite_zeroes(op->s->target, op->offset, op->bytes,
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op->s->unmap ? BDRV_REQ_MAY_UNMAP : 0);
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mirror_write_complete(op, ret);
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}
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static void coroutine_fn mirror_co_discard(void *opaque)
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{
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MirrorOp *op = opaque;
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int ret;
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op->s->in_flight++;
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op->s->bytes_in_flight += op->bytes;
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*op->bytes_handled = op->bytes;
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op->is_in_flight = true;
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ret = blk_co_pdiscard(op->s->target, op->offset, op->bytes);
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mirror_write_complete(op, ret);
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}
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static unsigned mirror_perform(MirrorBlockJob *s, int64_t offset,
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unsigned bytes, MirrorMethod mirror_method)
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{
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MirrorOp *op;
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Coroutine *co;
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int64_t bytes_handled = -1;
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op = g_new(MirrorOp, 1);
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*op = (MirrorOp){
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.s = s,
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.offset = offset,
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.bytes = bytes,
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.bytes_handled = &bytes_handled,
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};
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qemu_co_queue_init(&op->waiting_requests);
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switch (mirror_method) {
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case MIRROR_METHOD_COPY:
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co = qemu_coroutine_create(mirror_co_read, op);
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break;
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case MIRROR_METHOD_ZERO:
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co = qemu_coroutine_create(mirror_co_zero, op);
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break;
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case MIRROR_METHOD_DISCARD:
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co = qemu_coroutine_create(mirror_co_discard, op);
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break;
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default:
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abort();
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}
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op->co = co;
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QTAILQ_INSERT_TAIL(&s->ops_in_flight, op, next);
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qemu_coroutine_enter(co);
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/* At this point, ownership of op has been moved to the coroutine
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* and the object may already be freed */
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/* Assert that this value has been set */
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assert(bytes_handled >= 0);
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/* Same assertion as in mirror_co_read() (and for mirror_co_read()
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* and mirror_co_discard(), bytes_handled == op->bytes, which
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* is the @bytes parameter given to this function) */
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assert(bytes_handled <= UINT_MAX);
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return bytes_handled;
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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 = s->mirror_top_bs->backing->bs;
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MirrorOp *pseudo_op;
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int64_t offset;
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uint64_t delay_ns = 0, ret = 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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bool write_zeroes_ok = bdrv_can_write_zeroes_with_unmap(blk_bs(s->target));
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int max_io_bytes = MAX(s->buf_size / MAX_IN_FLIGHT, MAX_IO_BYTES);
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bdrv_dirty_bitmap_lock(s->dirty_bitmap);
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offset = bdrv_dirty_iter_next(s->dbi);
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if (offset < 0) {
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bdrv_set_dirty_iter(s->dbi, 0);
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offset = 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(offset >= 0);
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}
|
|
bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
|
|
|
|
/*
|
|
* Wait for concurrent requests to @offset. The next loop will limit the
|
|
* copied area based on in_flight_bitmap so we only copy an area that does
|
|
* not overlap with concurrent in-flight requests. Still, we would like to
|
|
* copy something, so wait until there are at least no more requests to the
|
|
* very beginning of the area.
|
|
*/
|
|
mirror_wait_on_conflicts(NULL, s, offset, 1);
|
|
|
|
job_pause_point(&s->common.job);
|
|
|
|
/* Find the number of consective dirty chunks following the first dirty
|
|
* one, and wait for in flight requests in them. */
|
|
bdrv_dirty_bitmap_lock(s->dirty_bitmap);
|
|
while (nb_chunks * s->granularity < s->buf_size) {
|
|
int64_t next_dirty;
|
|
int64_t next_offset = offset + nb_chunks * s->granularity;
|
|
int64_t next_chunk = next_offset / s->granularity;
|
|
if (next_offset >= s->bdev_length ||
|
|
!bdrv_dirty_bitmap_get_locked(s->dirty_bitmap, next_offset)) {
|
|
break;
|
|
}
|
|
if (test_bit(next_chunk, s->in_flight_bitmap)) {
|
|
break;
|
|
}
|
|
|
|
next_dirty = bdrv_dirty_iter_next(s->dbi);
|
|
if (next_dirty > next_offset || next_dirty < 0) {
|
|
/* The bitmap iterator's cache is stale, refresh it */
|
|
bdrv_set_dirty_iter(s->dbi, next_offset);
|
|
next_dirty = bdrv_dirty_iter_next(s->dbi);
|
|
}
|
|
assert(next_dirty == next_offset);
|
|
nb_chunks++;
|
|
}
|
|
|
|
/* Clear dirty bits before querying the block status, because
|
|
* calling bdrv_block_status_above could yield - if some blocks are
|
|
* marked dirty in this window, we need to know.
|
|
*/
|
|
bdrv_reset_dirty_bitmap_locked(s->dirty_bitmap, offset,
|
|
nb_chunks * s->granularity);
|
|
bdrv_dirty_bitmap_unlock(s->dirty_bitmap);
|
|
|
|
/* Before claiming an area in the in-flight bitmap, we have to
|
|
* create a MirrorOp for it so that conflicting requests can wait
|
|
* for it. mirror_perform() will create the real MirrorOps later,
|
|
* for now we just create a pseudo operation that will wake up all
|
|
* conflicting requests once all real operations have been
|
|
* launched. */
|
|
pseudo_op = g_new(MirrorOp, 1);
|
|
*pseudo_op = (MirrorOp){
|
|
.offset = offset,
|
|
.bytes = nb_chunks * s->granularity,
|
|
.is_pseudo_op = true,
|
|
};
|
|
qemu_co_queue_init(&pseudo_op->waiting_requests);
|
|
QTAILQ_INSERT_TAIL(&s->ops_in_flight, pseudo_op, next);
|
|
|
|
bitmap_set(s->in_flight_bitmap, offset / s->granularity, nb_chunks);
|
|
while (nb_chunks > 0 && offset < s->bdev_length) {
|
|
int ret;
|
|
int64_t io_bytes;
|
|
int64_t io_bytes_acct;
|
|
MirrorMethod mirror_method = MIRROR_METHOD_COPY;
|
|
|
|
assert(!(offset % s->granularity));
|
|
WITH_GRAPH_RDLOCK_GUARD() {
|
|
ret = bdrv_block_status_above(source, NULL, offset,
|
|
nb_chunks * s->granularity,
|
|
&io_bytes, NULL, NULL);
|
|
}
|
|
if (ret < 0) {
|
|
io_bytes = MIN(nb_chunks * s->granularity, max_io_bytes);
|
|
} else if (ret & BDRV_BLOCK_DATA) {
|
|
io_bytes = MIN(io_bytes, max_io_bytes);
|
|
}
|
|
|
|
io_bytes -= io_bytes % s->granularity;
|
|
if (io_bytes < s->granularity) {
|
|
io_bytes = s->granularity;
|
|
} else if (ret >= 0 && !(ret & BDRV_BLOCK_DATA)) {
|
|
int64_t target_offset;
|
|
int64_t target_bytes;
|
|
bdrv_round_to_clusters(blk_bs(s->target), offset, io_bytes,
|
|
&target_offset, &target_bytes);
|
|
if (target_offset == offset &&
|
|
target_bytes == io_bytes) {
|
|
mirror_method = ret & BDRV_BLOCK_ZERO ?
|
|
MIRROR_METHOD_ZERO :
|
|
MIRROR_METHOD_DISCARD;
|
|
}
|
|
}
|
|
|
|
while (s->in_flight >= MAX_IN_FLIGHT) {
|
|
trace_mirror_yield_in_flight(s, offset, s->in_flight);
|
|
mirror_wait_for_free_in_flight_slot(s);
|
|
}
|
|
|
|
if (s->ret < 0) {
|
|
ret = 0;
|
|
goto fail;
|
|
}
|
|
|
|
io_bytes = mirror_clip_bytes(s, offset, io_bytes);
|
|
io_bytes = mirror_perform(s, offset, io_bytes, mirror_method);
|
|
if (mirror_method != MIRROR_METHOD_COPY && write_zeroes_ok) {
|
|
io_bytes_acct = 0;
|
|
} else {
|
|
io_bytes_acct = io_bytes;
|
|
}
|
|
assert(io_bytes);
|
|
offset += io_bytes;
|
|
nb_chunks -= DIV_ROUND_UP(io_bytes, s->granularity);
|
|
delay_ns = block_job_ratelimit_get_delay(&s->common, io_bytes_acct);
|
|
}
|
|
|
|
ret = delay_ns;
|
|
fail:
|
|
QTAILQ_REMOVE(&s->ops_in_flight, pseudo_op, next);
|
|
qemu_co_queue_restart_all(&pseudo_op->waiting_requests);
|
|
g_free(pseudo_op);
|
|
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
/* 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 coroutine_fn mirror_wait_for_all_io(MirrorBlockJob *s)
|
|
{
|
|
while (s->in_flight > 0) {
|
|
mirror_wait_for_free_in_flight_slot(s);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* mirror_exit_common: handle both abort() and prepare() cases.
|
|
* for .prepare, returns 0 on success and -errno on failure.
|
|
* for .abort cases, denoted by abort = true, MUST return 0.
|
|
*/
|
|
static int mirror_exit_common(Job *job)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
|
|
BlockJob *bjob = &s->common;
|
|
MirrorBDSOpaque *bs_opaque;
|
|
AioContext *replace_aio_context = NULL;
|
|
BlockDriverState *src;
|
|
BlockDriverState *target_bs;
|
|
BlockDriverState *mirror_top_bs;
|
|
Error *local_err = NULL;
|
|
bool abort = job->ret < 0;
|
|
int ret = 0;
|
|
|
|
if (s->prepared) {
|
|
return 0;
|
|
}
|
|
s->prepared = true;
|
|
|
|
mirror_top_bs = s->mirror_top_bs;
|
|
bs_opaque = mirror_top_bs->opaque;
|
|
src = mirror_top_bs->backing->bs;
|
|
target_bs = blk_bs(s->target);
|
|
|
|
if (bdrv_chain_contains(src, target_bs)) {
|
|
bdrv_unfreeze_backing_chain(mirror_top_bs, target_bs);
|
|
}
|
|
|
|
bdrv_release_dirty_bitmap(s->dirty_bitmap);
|
|
|
|
/* Make sure that the source BDS doesn't go away during bdrv_replace_node,
|
|
* before we can call bdrv_drained_end */
|
|
bdrv_ref(src);
|
|
bdrv_ref(mirror_top_bs);
|
|
bdrv_ref(target_bs);
|
|
|
|
/*
|
|
* Remove target parent that still uses BLK_PERM_WRITE/RESIZE before
|
|
* inserting target_bs at s->to_replace, where we might not be able to get
|
|
* these permissions.
|
|
*/
|
|
blk_unref(s->target);
|
|
s->target = NULL;
|
|
|
|
/* We don't access the source any more. Dropping any WRITE/RESIZE is
|
|
* required before it could become a backing file of target_bs. Not having
|
|
* these permissions any more means that we can't allow any new requests on
|
|
* mirror_top_bs from now on, so keep it drained. */
|
|
bdrv_drained_begin(mirror_top_bs);
|
|
bs_opaque->stop = true;
|
|
bdrv_child_refresh_perms(mirror_top_bs, mirror_top_bs->backing,
|
|
&error_abort);
|
|
if (!abort && s->backing_mode == MIRROR_SOURCE_BACKING_CHAIN) {
|
|
BlockDriverState *backing = s->is_none_mode ? src : s->base;
|
|
BlockDriverState *unfiltered_target = bdrv_skip_filters(target_bs);
|
|
|
|
if (bdrv_cow_bs(unfiltered_target) != backing) {
|
|
bdrv_set_backing_hd(unfiltered_target, backing, &local_err);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
local_err = NULL;
|
|
ret = -EPERM;
|
|
}
|
|
}
|
|
} else if (!abort && s->backing_mode == MIRROR_OPEN_BACKING_CHAIN) {
|
|
assert(!bdrv_backing_chain_next(target_bs));
|
|
ret = bdrv_open_backing_file(bdrv_skip_filters(target_bs), NULL,
|
|
"backing", &local_err);
|
|
if (ret < 0) {
|
|
error_report_err(local_err);
|
|
local_err = NULL;
|
|
}
|
|
}
|
|
|
|
if (s->to_replace) {
|
|
replace_aio_context = bdrv_get_aio_context(s->to_replace);
|
|
aio_context_acquire(replace_aio_context);
|
|
}
|
|
|
|
if (s->should_complete && !abort) {
|
|
BlockDriverState *to_replace = s->to_replace ?: src;
|
|
bool ro = bdrv_is_read_only(to_replace);
|
|
|
|
if (ro != bdrv_is_read_only(target_bs)) {
|
|
bdrv_reopen_set_read_only(target_bs, ro, 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. */
|
|
assert(s->in_drain);
|
|
bdrv_drained_begin(target_bs);
|
|
/*
|
|
* Cannot use check_to_replace_node() here, because that would
|
|
* check for an op blocker on @to_replace, and we have our own
|
|
* there.
|
|
*/
|
|
if (bdrv_recurse_can_replace(src, to_replace)) {
|
|
bdrv_replace_node(to_replace, target_bs, &local_err);
|
|
} else {
|
|
error_setg(&local_err, "Can no longer replace '%s' by '%s', "
|
|
"because it can no longer be guaranteed that doing so "
|
|
"would not lead to an abrupt change of visible data",
|
|
to_replace->node_name, target_bs->node_name);
|
|
}
|
|
bdrv_drained_end(target_bs);
|
|
if (local_err) {
|
|
error_report_err(local_err);
|
|
ret = -EPERM;
|
|
}
|
|
}
|
|
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_unref(target_bs);
|
|
|
|
/*
|
|
* Remove the mirror filter driver from the graph. Before this, get rid of
|
|
* the blockers on the intermediate nodes so that the resulting state is
|
|
* valid.
|
|
*/
|
|
block_job_remove_all_bdrv(bjob);
|
|
bdrv_replace_node(mirror_top_bs, mirror_top_bs->backing->bs, &error_abort);
|
|
|
|
bs_opaque->job = NULL;
|
|
|
|
bdrv_drained_end(src);
|
|
bdrv_drained_end(mirror_top_bs);
|
|
s->in_drain = false;
|
|
bdrv_unref(mirror_top_bs);
|
|
bdrv_unref(src);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mirror_prepare(Job *job)
|
|
{
|
|
return mirror_exit_common(job);
|
|
}
|
|
|
|
static void mirror_abort(Job *job)
|
|
{
|
|
int ret = mirror_exit_common(job);
|
|
assert(ret == 0);
|
|
}
|
|
|
|
static void coroutine_fn mirror_throttle(MirrorBlockJob *s)
|
|
{
|
|
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
|
|
|
|
if (now - s->last_pause_ns > BLOCK_JOB_SLICE_TIME) {
|
|
s->last_pause_ns = now;
|
|
job_sleep_ns(&s->common.job, 0);
|
|
} else {
|
|
job_pause_point(&s->common.job);
|
|
}
|
|
}
|
|
|
|
static int coroutine_fn mirror_dirty_init(MirrorBlockJob *s)
|
|
{
|
|
int64_t offset;
|
|
BlockDriverState *bs = s->mirror_top_bs->backing->bs;
|
|
BlockDriverState *target_bs = blk_bs(s->target);
|
|
int ret;
|
|
int64_t count;
|
|
|
|
if (s->zero_target) {
|
|
if (!bdrv_can_write_zeroes_with_unmap(target_bs)) {
|
|
bdrv_set_dirty_bitmap(s->dirty_bitmap, 0, s->bdev_length);
|
|
return 0;
|
|
}
|
|
|
|
s->initial_zeroing_ongoing = true;
|
|
for (offset = 0; offset < s->bdev_length; ) {
|
|
int bytes = MIN(s->bdev_length - offset,
|
|
QEMU_ALIGN_DOWN(INT_MAX, s->granularity));
|
|
|
|
mirror_throttle(s);
|
|
|
|
if (job_is_cancelled(&s->common.job)) {
|
|
s->initial_zeroing_ongoing = false;
|
|
return 0;
|
|
}
|
|
|
|
if (s->in_flight >= MAX_IN_FLIGHT) {
|
|
trace_mirror_yield(s, UINT64_MAX, s->buf_free_count,
|
|
s->in_flight);
|
|
mirror_wait_for_free_in_flight_slot(s);
|
|
continue;
|
|
}
|
|
|
|
mirror_perform(s, offset, bytes, MIRROR_METHOD_ZERO);
|
|
offset += bytes;
|
|
}
|
|
|
|
mirror_wait_for_all_io(s);
|
|
s->initial_zeroing_ongoing = false;
|
|
}
|
|
|
|
/* First part, loop on the sectors and initialize the dirty bitmap. */
|
|
for (offset = 0; offset < s->bdev_length; ) {
|
|
/* Just to make sure we are not exceeding int limit. */
|
|
int bytes = MIN(s->bdev_length - offset,
|
|
QEMU_ALIGN_DOWN(INT_MAX, s->granularity));
|
|
|
|
mirror_throttle(s);
|
|
|
|
if (job_is_cancelled(&s->common.job)) {
|
|
return 0;
|
|
}
|
|
|
|
WITH_GRAPH_RDLOCK_GUARD() {
|
|
ret = bdrv_is_allocated_above(bs, s->base_overlay, true, offset,
|
|
bytes, &count);
|
|
}
|
|
if (ret < 0) {
|
|
return ret;
|
|
}
|
|
|
|
assert(count);
|
|
if (ret > 0) {
|
|
bdrv_set_dirty_bitmap(s->dirty_bitmap, offset, count);
|
|
}
|
|
offset += count;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Called when going out of the streaming phase to flush the bulk of the
|
|
* data to the medium, or just before completing.
|
|
*/
|
|
static int mirror_flush(MirrorBlockJob *s)
|
|
{
|
|
int ret = blk_flush(s->target);
|
|
if (ret < 0) {
|
|
if (mirror_error_action(s, false, -ret) == BLOCK_ERROR_ACTION_REPORT) {
|
|
s->ret = ret;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn mirror_run(Job *job, Error **errp)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
|
|
BlockDriverState *bs = s->mirror_top_bs->backing->bs;
|
|
MirrorBDSOpaque *mirror_top_opaque = s->mirror_top_bs->opaque;
|
|
BlockDriverState *target_bs = blk_bs(s->target);
|
|
bool need_drain = true;
|
|
BlockDeviceIoStatus iostatus;
|
|
int64_t length;
|
|
int64_t target_length;
|
|
BlockDriverInfo bdi;
|
|
char backing_filename[2]; /* we only need 2 characters because we are only
|
|
checking for a NULL string */
|
|
int ret = 0;
|
|
|
|
if (job_is_cancelled(&s->common.job)) {
|
|
goto immediate_exit;
|
|
}
|
|
|
|
bdrv_graph_co_rdlock();
|
|
s->bdev_length = bdrv_co_getlength(bs);
|
|
bdrv_graph_co_rdunlock();
|
|
|
|
if (s->bdev_length < 0) {
|
|
ret = s->bdev_length;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
target_length = blk_co_getlength(s->target);
|
|
if (target_length < 0) {
|
|
ret = target_length;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
/* Active commit must resize the base image if its size differs from the
|
|
* active layer. */
|
|
if (s->base == blk_bs(s->target)) {
|
|
if (s->bdev_length > target_length) {
|
|
ret = blk_co_truncate(s->target, s->bdev_length, false,
|
|
PREALLOC_MODE_OFF, 0, NULL);
|
|
if (ret < 0) {
|
|
goto immediate_exit;
|
|
}
|
|
}
|
|
} else if (s->bdev_length != target_length) {
|
|
error_setg(errp, "Source and target image have different sizes");
|
|
ret = -EINVAL;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
if (s->bdev_length == 0) {
|
|
/* Transition to the READY state and wait for complete. */
|
|
job_transition_to_ready(&s->common.job);
|
|
s->actively_synced = true;
|
|
while (!job_cancel_requested(&s->common.job) && !s->should_complete) {
|
|
job_yield(&s->common.job);
|
|
}
|
|
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_co_get_info(target_bs, &bdi) && bdi.cluster_size) {
|
|
s->target_cluster_size = bdi.cluster_size;
|
|
} else {
|
|
s->target_cluster_size = BDRV_SECTOR_SIZE;
|
|
}
|
|
if (backing_filename[0] && !bdrv_backing_chain_next(target_bs) &&
|
|
s->granularity < s->target_cluster_size) {
|
|
s->buf_size = MAX(s->buf_size, s->target_cluster_size);
|
|
s->cow_bitmap = bitmap_new(length);
|
|
}
|
|
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 || job_is_cancelled(&s->common.job)) {
|
|
goto immediate_exit;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Only now the job is fully initialised and mirror_top_bs should start
|
|
* accessing it.
|
|
*/
|
|
mirror_top_opaque->job = s;
|
|
|
|
assert(!s->dbi);
|
|
s->dbi = bdrv_dirty_iter_new(s->dirty_bitmap);
|
|
for (;;) {
|
|
uint64_t delay_ns = 0;
|
|
int64_t cnt, delta;
|
|
bool should_complete;
|
|
|
|
if (s->ret < 0) {
|
|
ret = s->ret;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
job_pause_point(&s->common.job);
|
|
|
|
if (job_is_cancelled(&s->common.job)) {
|
|
ret = 0;
|
|
goto immediate_exit;
|
|
}
|
|
|
|
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
|
|
/* cnt is the number of dirty bytes remaining and s->bytes_in_flight is
|
|
* the number of bytes currently being processed; together those are
|
|
* the current remaining operation length */
|
|
job_progress_set_remaining(&s->common.job,
|
|
s->bytes_in_flight + cnt +
|
|
s->active_write_bytes_in_flight);
|
|
|
|
/* 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 BLKOCK_JOB_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;
|
|
WITH_JOB_LOCK_GUARD() {
|
|
iostatus = s->common.iostatus;
|
|
}
|
|
if (delta < BLOCK_JOB_SLICE_TIME &&
|
|
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, cnt, s->buf_free_count, s->in_flight);
|
|
mirror_wait_for_free_in_flight_slot(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);
|
|
if (!job_is_ready(&s->common.job)) {
|
|
if (mirror_flush(s) < 0) {
|
|
/* Go check s->ret. */
|
|
continue;
|
|
}
|
|
/* 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.
|
|
*/
|
|
job_transition_to_ready(&s->common.job);
|
|
if (s->copy_mode != MIRROR_COPY_MODE_BACKGROUND) {
|
|
s->actively_synced = true;
|
|
}
|
|
}
|
|
|
|
should_complete = s->should_complete ||
|
|
job_cancel_requested(&s->common.job);
|
|
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);
|
|
|
|
s->in_drain = true;
|
|
bdrv_drained_begin(bs);
|
|
|
|
/* Must be zero because we are drained */
|
|
assert(s->in_active_write_counter == 0);
|
|
|
|
cnt = bdrv_get_dirty_count(s->dirty_bitmap);
|
|
if (cnt > 0 || mirror_flush(s) < 0) {
|
|
bdrv_drained_end(bs);
|
|
s->in_drain = false;
|
|
continue;
|
|
}
|
|
|
|
/* The two disks are in sync. Exit and report successful
|
|
* completion.
|
|
*/
|
|
assert(QLIST_EMPTY(&bs->tracked_requests));
|
|
need_drain = false;
|
|
break;
|
|
}
|
|
|
|
if (job_is_ready(&s->common.job) && !should_complete) {
|
|
delay_ns = (s->in_flight == 0 &&
|
|
cnt == 0 ? BLOCK_JOB_SLICE_TIME : 0);
|
|
}
|
|
trace_mirror_before_sleep(s, cnt, job_is_ready(&s->common.job),
|
|
delay_ns);
|
|
job_sleep_ns(&s->common.job, 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 || job_is_cancelled(&s->common.job));
|
|
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);
|
|
|
|
if (need_drain) {
|
|
s->in_drain = true;
|
|
bdrv_drained_begin(bs);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void mirror_complete(Job *job, Error **errp)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
|
|
|
|
if (!job_is_ready(job)) {
|
|
error_setg(errp, "The active block job '%s' cannot be completed",
|
|
job->id);
|
|
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);
|
|
|
|
/* TODO Translate this into child freeze system. */
|
|
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;
|
|
|
|
/* If the job is paused, it will be re-entered when it is resumed */
|
|
WITH_JOB_LOCK_GUARD() {
|
|
if (!job->paused) {
|
|
job_enter_cond_locked(job, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void coroutine_fn mirror_pause(Job *job)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
|
|
|
|
mirror_wait_for_all_io(s);
|
|
}
|
|
|
|
static bool mirror_drained_poll(BlockJob *job)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common);
|
|
|
|
/* If the job isn't paused nor cancelled, we can't be sure that it won't
|
|
* issue more requests. We make an exception if we've reached this point
|
|
* from one of our own drain sections, to avoid a deadlock waiting for
|
|
* ourselves.
|
|
*/
|
|
WITH_JOB_LOCK_GUARD() {
|
|
if (!s->common.job.paused && !job_is_cancelled_locked(&job->job)
|
|
&& !s->in_drain) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return !!s->in_flight;
|
|
}
|
|
|
|
static bool mirror_cancel(Job *job, bool force)
|
|
{
|
|
MirrorBlockJob *s = container_of(job, MirrorBlockJob, common.job);
|
|
BlockDriverState *target = blk_bs(s->target);
|
|
|
|
/*
|
|
* Before the job is READY, we treat any cancellation like a
|
|
* force-cancellation.
|
|
*/
|
|
force = force || !job_is_ready(job);
|
|
|
|
if (force) {
|
|
bdrv_cancel_in_flight(target);
|
|
}
|
|
return force;
|
|
}
|
|
|
|
static bool commit_active_cancel(Job *job, bool force)
|
|
{
|
|
/* Same as above in mirror_cancel() */
|
|
return force || !job_is_ready(job);
|
|
}
|
|
|
|
static const BlockJobDriver mirror_job_driver = {
|
|
.job_driver = {
|
|
.instance_size = sizeof(MirrorBlockJob),
|
|
.job_type = JOB_TYPE_MIRROR,
|
|
.free = block_job_free,
|
|
.user_resume = block_job_user_resume,
|
|
.run = mirror_run,
|
|
.prepare = mirror_prepare,
|
|
.abort = mirror_abort,
|
|
.pause = mirror_pause,
|
|
.complete = mirror_complete,
|
|
.cancel = mirror_cancel,
|
|
},
|
|
.drained_poll = mirror_drained_poll,
|
|
};
|
|
|
|
static const BlockJobDriver commit_active_job_driver = {
|
|
.job_driver = {
|
|
.instance_size = sizeof(MirrorBlockJob),
|
|
.job_type = JOB_TYPE_COMMIT,
|
|
.free = block_job_free,
|
|
.user_resume = block_job_user_resume,
|
|
.run = mirror_run,
|
|
.prepare = mirror_prepare,
|
|
.abort = mirror_abort,
|
|
.pause = mirror_pause,
|
|
.complete = mirror_complete,
|
|
.cancel = commit_active_cancel,
|
|
},
|
|
.drained_poll = mirror_drained_poll,
|
|
};
|
|
|
|
static void coroutine_fn
|
|
do_sync_target_write(MirrorBlockJob *job, MirrorMethod method,
|
|
uint64_t offset, uint64_t bytes,
|
|
QEMUIOVector *qiov, int flags)
|
|
{
|
|
int ret;
|
|
size_t qiov_offset = 0;
|
|
int64_t bitmap_offset, bitmap_end;
|
|
|
|
if (!QEMU_IS_ALIGNED(offset, job->granularity) &&
|
|
bdrv_dirty_bitmap_get(job->dirty_bitmap, offset))
|
|
{
|
|
/*
|
|
* Dirty unaligned padding: ignore it.
|
|
*
|
|
* Reasoning:
|
|
* 1. If we copy it, we can't reset corresponding bit in
|
|
* dirty_bitmap as there may be some "dirty" bytes still not
|
|
* copied.
|
|
* 2. It's already dirty, so skipping it we don't diverge mirror
|
|
* progress.
|
|
*
|
|
* Note, that because of this, guest write may have no contribution
|
|
* into mirror converge, but that's not bad, as we have background
|
|
* process of mirroring. If under some bad circumstances (high guest
|
|
* IO load) background process starve, we will not converge anyway,
|
|
* even if each write will contribute, as guest is not guaranteed to
|
|
* rewrite the whole disk.
|
|
*/
|
|
qiov_offset = QEMU_ALIGN_UP(offset, job->granularity) - offset;
|
|
if (bytes <= qiov_offset) {
|
|
/* nothing to do after shrink */
|
|
return;
|
|
}
|
|
offset += qiov_offset;
|
|
bytes -= qiov_offset;
|
|
}
|
|
|
|
if (!QEMU_IS_ALIGNED(offset + bytes, job->granularity) &&
|
|
bdrv_dirty_bitmap_get(job->dirty_bitmap, offset + bytes - 1))
|
|
{
|
|
uint64_t tail = (offset + bytes) % job->granularity;
|
|
|
|
if (bytes <= tail) {
|
|
/* nothing to do after shrink */
|
|
return;
|
|
}
|
|
bytes -= tail;
|
|
}
|
|
|
|
/*
|
|
* Tails are either clean or shrunk, so for bitmap resetting
|
|
* we safely align the range down.
|
|
*/
|
|
bitmap_offset = QEMU_ALIGN_UP(offset, job->granularity);
|
|
bitmap_end = QEMU_ALIGN_DOWN(offset + bytes, job->granularity);
|
|
if (bitmap_offset < bitmap_end) {
|
|
bdrv_reset_dirty_bitmap(job->dirty_bitmap, bitmap_offset,
|
|
bitmap_end - bitmap_offset);
|
|
}
|
|
|
|
job_progress_increase_remaining(&job->common.job, bytes);
|
|
job->active_write_bytes_in_flight += bytes;
|
|
|
|
switch (method) {
|
|
case MIRROR_METHOD_COPY:
|
|
ret = blk_co_pwritev_part(job->target, offset, bytes,
|
|
qiov, qiov_offset, flags);
|
|
break;
|
|
|
|
case MIRROR_METHOD_ZERO:
|
|
assert(!qiov);
|
|
ret = blk_co_pwrite_zeroes(job->target, offset, bytes, flags);
|
|
break;
|
|
|
|
case MIRROR_METHOD_DISCARD:
|
|
assert(!qiov);
|
|
ret = blk_co_pdiscard(job->target, offset, bytes);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
|
|
job->active_write_bytes_in_flight -= bytes;
|
|
if (ret >= 0) {
|
|
job_progress_update(&job->common.job, bytes);
|
|
} else {
|
|
BlockErrorAction action;
|
|
|
|
/*
|
|
* We failed, so we should mark dirty the whole area, aligned up.
|
|
* Note that we don't care about shrunk tails if any: they were dirty
|
|
* at function start, and they must be still dirty, as we've locked
|
|
* the region for in-flight op.
|
|
*/
|
|
bitmap_offset = QEMU_ALIGN_DOWN(offset, job->granularity);
|
|
bitmap_end = QEMU_ALIGN_UP(offset + bytes, job->granularity);
|
|
bdrv_set_dirty_bitmap(job->dirty_bitmap, bitmap_offset,
|
|
bitmap_end - bitmap_offset);
|
|
job->actively_synced = false;
|
|
|
|
action = mirror_error_action(job, false, -ret);
|
|
if (action == BLOCK_ERROR_ACTION_REPORT) {
|
|
if (!job->ret) {
|
|
job->ret = ret;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static MirrorOp *coroutine_fn active_write_prepare(MirrorBlockJob *s,
|
|
uint64_t offset,
|
|
uint64_t bytes)
|
|
{
|
|
MirrorOp *op;
|
|
uint64_t start_chunk = offset / s->granularity;
|
|
uint64_t end_chunk = DIV_ROUND_UP(offset + bytes, s->granularity);
|
|
|
|
op = g_new(MirrorOp, 1);
|
|
*op = (MirrorOp){
|
|
.s = s,
|
|
.offset = offset,
|
|
.bytes = bytes,
|
|
.is_active_write = true,
|
|
.is_in_flight = true,
|
|
.co = qemu_coroutine_self(),
|
|
};
|
|
qemu_co_queue_init(&op->waiting_requests);
|
|
QTAILQ_INSERT_TAIL(&s->ops_in_flight, op, next);
|
|
|
|
s->in_active_write_counter++;
|
|
|
|
/*
|
|
* Wait for concurrent requests affecting the area. If there are already
|
|
* running requests that are copying off now-to-be stale data in the area,
|
|
* we must wait for them to finish before we begin writing fresh data to the
|
|
* target so that the write operations appear in the correct order.
|
|
* Note that background requests (see mirror_iteration()) in contrast only
|
|
* wait for conflicting requests at the start of the dirty area, and then
|
|
* (based on the in_flight_bitmap) truncate the area to copy so it will not
|
|
* conflict with any requests beyond that. For active writes, however, we
|
|
* cannot truncate that area. The request from our parent must be blocked
|
|
* until the area is copied in full. Therefore, we must wait for the whole
|
|
* area to become free of concurrent requests.
|
|
*/
|
|
mirror_wait_on_conflicts(op, s, offset, bytes);
|
|
|
|
bitmap_set(s->in_flight_bitmap, start_chunk, end_chunk - start_chunk);
|
|
|
|
return op;
|
|
}
|
|
|
|
static void coroutine_fn active_write_settle(MirrorOp *op)
|
|
{
|
|
uint64_t start_chunk = op->offset / op->s->granularity;
|
|
uint64_t end_chunk = DIV_ROUND_UP(op->offset + op->bytes,
|
|
op->s->granularity);
|
|
|
|
if (!--op->s->in_active_write_counter && op->s->actively_synced) {
|
|
BdrvChild *source = op->s->mirror_top_bs->backing;
|
|
|
|
if (QLIST_FIRST(&source->bs->parents) == source &&
|
|
QLIST_NEXT(source, next_parent) == NULL)
|
|
{
|
|
/* Assert that we are back in sync once all active write
|
|
* operations are settled.
|
|
* Note that we can only assert this if the mirror node
|
|
* is the source node's only parent. */
|
|
assert(!bdrv_get_dirty_count(op->s->dirty_bitmap));
|
|
}
|
|
}
|
|
bitmap_clear(op->s->in_flight_bitmap, start_chunk, end_chunk - start_chunk);
|
|
QTAILQ_REMOVE(&op->s->ops_in_flight, op, next);
|
|
qemu_co_queue_restart_all(&op->waiting_requests);
|
|
g_free(op);
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK
|
|
bdrv_mirror_top_preadv(BlockDriverState *bs, int64_t offset, int64_t bytes,
|
|
QEMUIOVector *qiov, BdrvRequestFlags flags)
|
|
{
|
|
return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK
|
|
bdrv_mirror_top_do_write(BlockDriverState *bs, MirrorMethod method,
|
|
uint64_t offset, uint64_t bytes, QEMUIOVector *qiov,
|
|
int flags)
|
|
{
|
|
MirrorOp *op = NULL;
|
|
MirrorBDSOpaque *s = bs->opaque;
|
|
int ret = 0;
|
|
bool copy_to_target = false;
|
|
|
|
if (s->job) {
|
|
copy_to_target = s->job->ret >= 0 &&
|
|
!job_is_cancelled(&s->job->common.job) &&
|
|
s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING;
|
|
}
|
|
|
|
if (copy_to_target) {
|
|
op = active_write_prepare(s->job, offset, bytes);
|
|
}
|
|
|
|
switch (method) {
|
|
case MIRROR_METHOD_COPY:
|
|
ret = bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags);
|
|
break;
|
|
|
|
case MIRROR_METHOD_ZERO:
|
|
ret = bdrv_co_pwrite_zeroes(bs->backing, offset, bytes, flags);
|
|
break;
|
|
|
|
case MIRROR_METHOD_DISCARD:
|
|
ret = bdrv_co_pdiscard(bs->backing, offset, bytes);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
|
|
if (ret < 0) {
|
|
goto out;
|
|
}
|
|
|
|
if (copy_to_target) {
|
|
do_sync_target_write(s->job, method, offset, bytes, qiov, flags);
|
|
}
|
|
|
|
out:
|
|
if (copy_to_target) {
|
|
active_write_settle(op);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK
|
|
bdrv_mirror_top_pwritev(BlockDriverState *bs, int64_t offset, int64_t bytes,
|
|
QEMUIOVector *qiov, BdrvRequestFlags flags)
|
|
{
|
|
MirrorBDSOpaque *s = bs->opaque;
|
|
QEMUIOVector bounce_qiov;
|
|
void *bounce_buf;
|
|
int ret = 0;
|
|
bool copy_to_target = false;
|
|
|
|
if (s->job) {
|
|
copy_to_target = s->job->ret >= 0 &&
|
|
!job_is_cancelled(&s->job->common.job) &&
|
|
s->job->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING;
|
|
}
|
|
|
|
if (copy_to_target) {
|
|
/* The guest might concurrently modify the data to write; but
|
|
* the data on source and destination must match, so we have
|
|
* to use a bounce buffer if we are going to write to the
|
|
* target now. */
|
|
bounce_buf = qemu_blockalign(bs, bytes);
|
|
iov_to_buf_full(qiov->iov, qiov->niov, 0, bounce_buf, bytes);
|
|
|
|
qemu_iovec_init(&bounce_qiov, 1);
|
|
qemu_iovec_add(&bounce_qiov, bounce_buf, bytes);
|
|
qiov = &bounce_qiov;
|
|
|
|
flags &= ~BDRV_REQ_REGISTERED_BUF;
|
|
}
|
|
|
|
ret = bdrv_mirror_top_do_write(bs, MIRROR_METHOD_COPY, offset, bytes, qiov,
|
|
flags);
|
|
|
|
if (copy_to_target) {
|
|
qemu_iovec_destroy(&bounce_qiov);
|
|
qemu_vfree(bounce_buf);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK bdrv_mirror_top_flush(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing == NULL) {
|
|
/* we can be here after failed bdrv_append in mirror_start_job */
|
|
return 0;
|
|
}
|
|
return bdrv_co_flush(bs->backing->bs);
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK
|
|
bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs, int64_t offset,
|
|
int64_t bytes, BdrvRequestFlags flags)
|
|
{
|
|
return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_ZERO, offset, bytes, NULL,
|
|
flags);
|
|
}
|
|
|
|
static int coroutine_fn GRAPH_RDLOCK
|
|
bdrv_mirror_top_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
|
|
{
|
|
return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, offset, bytes,
|
|
NULL, 0);
|
|
}
|
|
|
|
static void bdrv_mirror_top_refresh_filename(BlockDriverState *bs)
|
|
{
|
|
if (bs->backing == NULL) {
|
|
/* we can be here after failed bdrv_attach_child in
|
|
* bdrv_set_backing_hd */
|
|
return;
|
|
}
|
|
pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
|
|
bs->backing->bs->filename);
|
|
}
|
|
|
|
static void bdrv_mirror_top_child_perm(BlockDriverState *bs, BdrvChild *c,
|
|
BdrvChildRole role,
|
|
BlockReopenQueue *reopen_queue,
|
|
uint64_t perm, uint64_t shared,
|
|
uint64_t *nperm, uint64_t *nshared)
|
|
{
|
|
MirrorBDSOpaque *s = bs->opaque;
|
|
|
|
if (s->stop) {
|
|
/*
|
|
* If the job is to be stopped, we do not need to forward
|
|
* anything to the real image.
|
|
*/
|
|
*nperm = 0;
|
|
*nshared = BLK_PERM_ALL;
|
|
return;
|
|
}
|
|
|
|
bdrv_default_perms(bs, c, role, reopen_queue,
|
|
perm, shared, nperm, nshared);
|
|
|
|
if (s->is_commit) {
|
|
/*
|
|
* For commit jobs, we cannot take CONSISTENT_READ, because
|
|
* that permission is unshared for everything above the base
|
|
* node (except for filters on the base node).
|
|
* We also have to force-share the WRITE permission, or
|
|
* otherwise we would block ourselves at the base node (if
|
|
* writes are blocked for a node, they are also blocked for
|
|
* its backing file).
|
|
* (We could also share RESIZE, because it may be needed for
|
|
* the target if its size is less than the top node's; but
|
|
* bdrv_default_perms_for_cow() automatically shares RESIZE
|
|
* for backing nodes if WRITE is shared, so there is no need
|
|
* to do it here.)
|
|
*/
|
|
*nperm &= ~BLK_PERM_CONSISTENT_READ;
|
|
*nshared |= BLK_PERM_WRITE;
|
|
}
|
|
}
|
|
|
|
/* Dummy node that provides consistent read to its users without requiring it
|
|
* from its backing file and that allows writes on the backing file chain. */
|
|
static BlockDriver bdrv_mirror_top = {
|
|
.format_name = "mirror_top",
|
|
.bdrv_co_preadv = bdrv_mirror_top_preadv,
|
|
.bdrv_co_pwritev = bdrv_mirror_top_pwritev,
|
|
.bdrv_co_pwrite_zeroes = bdrv_mirror_top_pwrite_zeroes,
|
|
.bdrv_co_pdiscard = bdrv_mirror_top_pdiscard,
|
|
.bdrv_co_flush = bdrv_mirror_top_flush,
|
|
.bdrv_refresh_filename = bdrv_mirror_top_refresh_filename,
|
|
.bdrv_child_perm = bdrv_mirror_top_child_perm,
|
|
|
|
.is_filter = true,
|
|
.filtered_child_is_backing = true,
|
|
};
|
|
|
|
static BlockJob *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,
|
|
bool zero_target,
|
|
BlockdevOnError on_source_error,
|
|
BlockdevOnError on_target_error,
|
|
bool unmap,
|
|
BlockCompletionFunc *cb,
|
|
void *opaque,
|
|
const BlockJobDriver *driver,
|
|
bool is_none_mode, BlockDriverState *base,
|
|
bool auto_complete, const char *filter_node_name,
|
|
bool is_mirror, MirrorCopyMode copy_mode,
|
|
Error **errp)
|
|
{
|
|
MirrorBlockJob *s;
|
|
MirrorBDSOpaque *bs_opaque;
|
|
BlockDriverState *mirror_top_bs;
|
|
bool target_is_backing;
|
|
uint64_t target_perms, target_shared_perms;
|
|
int ret;
|
|
|
|
if (granularity == 0) {
|
|
granularity = bdrv_get_default_bitmap_granularity(target);
|
|
}
|
|
|
|
assert(is_power_of_2(granularity));
|
|
|
|
if (buf_size < 0) {
|
|
error_setg(errp, "Invalid parameter 'buf-size'");
|
|
return NULL;
|
|
}
|
|
|
|
if (buf_size == 0) {
|
|
buf_size = DEFAULT_MIRROR_BUF_SIZE;
|
|
}
|
|
|
|
if (bdrv_skip_filters(bs) == bdrv_skip_filters(target)) {
|
|
error_setg(errp, "Can't mirror node into itself");
|
|
return NULL;
|
|
}
|
|
|
|
target_is_backing = bdrv_chain_contains(bs, target);
|
|
|
|
/* In the case of active commit, add dummy driver to provide consistent
|
|
* reads on the top, while disabling it in the intermediate nodes, and make
|
|
* the backing chain writable. */
|
|
mirror_top_bs = bdrv_new_open_driver(&bdrv_mirror_top, filter_node_name,
|
|
BDRV_O_RDWR, errp);
|
|
if (mirror_top_bs == NULL) {
|
|
return NULL;
|
|
}
|
|
if (!filter_node_name) {
|
|
mirror_top_bs->implicit = true;
|
|
}
|
|
|
|
/* So that we can always drop this node */
|
|
mirror_top_bs->never_freeze = true;
|
|
|
|
mirror_top_bs->total_sectors = bs->total_sectors;
|
|
mirror_top_bs->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED;
|
|
mirror_top_bs->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
|
|
BDRV_REQ_NO_FALLBACK;
|
|
bs_opaque = g_new0(MirrorBDSOpaque, 1);
|
|
mirror_top_bs->opaque = bs_opaque;
|
|
|
|
bs_opaque->is_commit = target_is_backing;
|
|
|
|
bdrv_drained_begin(bs);
|
|
ret = bdrv_append(mirror_top_bs, bs, errp);
|
|
bdrv_drained_end(bs);
|
|
|
|
if (ret < 0) {
|
|
bdrv_unref(mirror_top_bs);
|
|
return NULL;
|
|
}
|
|
|
|
/* Make sure that the source is not resized while the job is running */
|
|
s = block_job_create(job_id, driver, NULL, mirror_top_bs,
|
|
BLK_PERM_CONSISTENT_READ,
|
|
BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
|
|
BLK_PERM_WRITE, speed,
|
|
creation_flags, cb, opaque, errp);
|
|
if (!s) {
|
|
goto fail;
|
|
}
|
|
|
|
/* The block job now has a reference to this node */
|
|
bdrv_unref(mirror_top_bs);
|
|
|
|
s->mirror_top_bs = mirror_top_bs;
|
|
|
|
/* No resize for the target either; while the mirror is still running, a
|
|
* consistent read isn't necessarily possible. We could possibly allow
|
|
* writes and graph modifications, though it would likely defeat the
|
|
* purpose of a mirror, so leave them blocked for now.
|
|
*
|
|
* In the case of active commit, things look a bit different, though,
|
|
* because the target is an already populated backing file in active use.
|
|
* We can allow anything except resize there.*/
|
|
|
|
target_perms = BLK_PERM_WRITE;
|
|
target_shared_perms = BLK_PERM_WRITE_UNCHANGED;
|
|
|
|
if (target_is_backing) {
|
|
int64_t bs_size, target_size;
|
|
bs_size = bdrv_getlength(bs);
|
|
if (bs_size < 0) {
|
|
error_setg_errno(errp, -bs_size,
|
|
"Could not inquire top image size");
|
|
goto fail;
|
|
}
|
|
|
|
target_size = bdrv_getlength(target);
|
|
if (target_size < 0) {
|
|
error_setg_errno(errp, -target_size,
|
|
"Could not inquire base image size");
|
|
goto fail;
|
|
}
|
|
|
|
if (target_size < bs_size) {
|
|
target_perms |= BLK_PERM_RESIZE;
|
|
}
|
|
|
|
target_shared_perms |= BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE;
|
|
} else if (bdrv_chain_contains(bs, bdrv_skip_filters(target))) {
|
|
/*
|
|
* We may want to allow this in the future, but it would
|
|
* require taking some extra care.
|
|
*/
|
|
error_setg(errp, "Cannot mirror to a filter on top of a node in the "
|
|
"source's backing chain");
|
|
goto fail;
|
|
}
|
|
|
|
s->target = blk_new(s->common.job.aio_context,
|
|
target_perms, target_shared_perms);
|
|
ret = blk_insert_bs(s->target, target, errp);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
if (is_mirror) {
|
|
/* XXX: Mirror target could be a NBD server of target QEMU in the case
|
|
* of non-shared block migration. To allow migration completion, we
|
|
* have to allow "inactivate" of the target BB. When that happens, we
|
|
* know the job is drained, and the vcpus are stopped, so no write
|
|
* operation will be performed. Block layer already has assertions to
|
|
* ensure that. */
|
|
blk_set_force_allow_inactivate(s->target);
|
|
}
|
|
blk_set_allow_aio_context_change(s->target, true);
|
|
blk_set_disable_request_queuing(s->target, true);
|
|
|
|
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->zero_target = zero_target;
|
|
s->copy_mode = copy_mode;
|
|
s->base = base;
|
|
s->base_overlay = bdrv_find_overlay(bs, 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) {
|
|
goto fail;
|
|
}
|
|
if (s->copy_mode == MIRROR_COPY_MODE_WRITE_BLOCKING) {
|
|
bdrv_disable_dirty_bitmap(s->dirty_bitmap);
|
|
}
|
|
|
|
ret = block_job_add_bdrv(&s->common, "source", bs, 0,
|
|
BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE |
|
|
BLK_PERM_CONSISTENT_READ,
|
|
errp);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
|
|
/* Required permissions are already taken with blk_new() */
|
|
block_job_add_bdrv(&s->common, "target", target, 0, BLK_PERM_ALL,
|
|
&error_abort);
|
|
|
|
/* In commit_active_start() all intermediate nodes disappear, so
|
|
* any jobs in them must be blocked */
|
|
if (target_is_backing) {
|
|
BlockDriverState *iter, *filtered_target;
|
|
uint64_t iter_shared_perms;
|
|
|
|
/*
|
|
* The topmost node with
|
|
* bdrv_skip_filters(filtered_target) == bdrv_skip_filters(target)
|
|
*/
|
|
filtered_target = bdrv_cow_bs(bdrv_find_overlay(bs, target));
|
|
|
|
assert(bdrv_skip_filters(filtered_target) ==
|
|
bdrv_skip_filters(target));
|
|
|
|
/*
|
|
* XXX BLK_PERM_WRITE needs to be allowed so we don't block
|
|
* ourselves at s->base (if writes are blocked for a node, they are
|
|
* also blocked for its backing file). The other options would be a
|
|
* second filter driver above s->base (== target).
|
|
*/
|
|
iter_shared_perms = BLK_PERM_WRITE_UNCHANGED | BLK_PERM_WRITE;
|
|
|
|
for (iter = bdrv_filter_or_cow_bs(bs); iter != target;
|
|
iter = bdrv_filter_or_cow_bs(iter))
|
|
{
|
|
if (iter == filtered_target) {
|
|
/*
|
|
* From here on, all nodes are filters on the base.
|
|
* This allows us to share BLK_PERM_CONSISTENT_READ.
|
|
*/
|
|
iter_shared_perms |= BLK_PERM_CONSISTENT_READ;
|
|
}
|
|
|
|
ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
|
|
iter_shared_perms, errp);
|
|
if (ret < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
if (bdrv_freeze_backing_chain(mirror_top_bs, target, errp) < 0) {
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
QTAILQ_INIT(&s->ops_in_flight);
|
|
|
|
trace_mirror_start(bs, s, opaque);
|
|
job_start(&s->common.job);
|
|
|
|
return &s->common;
|
|
|
|
fail:
|
|
if (s) {
|
|
/* Make sure this BDS does not go away until we have completed the graph
|
|
* changes below */
|
|
bdrv_ref(mirror_top_bs);
|
|
|
|
g_free(s->replaces);
|
|
blk_unref(s->target);
|
|
bs_opaque->job = NULL;
|
|
if (s->dirty_bitmap) {
|
|
bdrv_release_dirty_bitmap(s->dirty_bitmap);
|
|
}
|
|
job_early_fail(&s->common.job);
|
|
}
|
|
|
|
bs_opaque->stop = true;
|
|
bdrv_child_refresh_perms(mirror_top_bs, mirror_top_bs->backing,
|
|
&error_abort);
|
|
bdrv_replace_node(mirror_top_bs, mirror_top_bs->backing->bs, &error_abort);
|
|
|
|
bdrv_unref(mirror_top_bs);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void mirror_start(const char *job_id, BlockDriverState *bs,
|
|
BlockDriverState *target, const char *replaces,
|
|
int creation_flags, int64_t speed,
|
|
uint32_t granularity, int64_t buf_size,
|
|
MirrorSyncMode mode, BlockMirrorBackingMode backing_mode,
|
|
bool zero_target,
|
|
BlockdevOnError on_source_error,
|
|
BlockdevOnError on_target_error,
|
|
bool unmap, const char *filter_node_name,
|
|
MirrorCopyMode copy_mode, Error **errp)
|
|
{
|
|
bool is_none_mode;
|
|
BlockDriverState *base;
|
|
|
|
GLOBAL_STATE_CODE();
|
|
|
|
if ((mode == MIRROR_SYNC_MODE_INCREMENTAL) ||
|
|
(mode == MIRROR_SYNC_MODE_BITMAP)) {
|
|
error_setg(errp, "Sync mode '%s' not supported",
|
|
MirrorSyncMode_str(mode));
|
|
return;
|
|
}
|
|
is_none_mode = mode == MIRROR_SYNC_MODE_NONE;
|
|
base = mode == MIRROR_SYNC_MODE_TOP ? bdrv_backing_chain_next(bs) : NULL;
|
|
mirror_start_job(job_id, bs, creation_flags, target, replaces,
|
|
speed, granularity, buf_size, backing_mode, zero_target,
|
|
on_source_error, on_target_error, unmap, NULL, NULL,
|
|
&mirror_job_driver, is_none_mode, base, false,
|
|
filter_node_name, true, copy_mode, errp);
|
|
}
|
|
|
|
BlockJob *commit_active_start(const char *job_id, BlockDriverState *bs,
|
|
BlockDriverState *base, int creation_flags,
|
|
int64_t speed, BlockdevOnError on_error,
|
|
const char *filter_node_name,
|
|
BlockCompletionFunc *cb, void *opaque,
|
|
bool auto_complete, Error **errp)
|
|
{
|
|
bool base_read_only;
|
|
BlockJob *job;
|
|
|
|
GLOBAL_STATE_CODE();
|
|
|
|
base_read_only = bdrv_is_read_only(base);
|
|
|
|
if (base_read_only) {
|
|
if (bdrv_reopen_set_read_only(base, false, errp) < 0) {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
job = mirror_start_job(
|
|
job_id, bs, creation_flags, base, NULL, speed, 0, 0,
|
|
MIRROR_LEAVE_BACKING_CHAIN, false,
|
|
on_error, on_error, true, cb, opaque,
|
|
&commit_active_job_driver, false, base, auto_complete,
|
|
filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND,
|
|
errp);
|
|
if (!job) {
|
|
goto error_restore_flags;
|
|
}
|
|
|
|
return job;
|
|
|
|
error_restore_flags:
|
|
/* ignore error and errp for bdrv_reopen, because we want to propagate
|
|
* the original error */
|
|
if (base_read_only) {
|
|
bdrv_reopen_set_read_only(base, true, NULL);
|
|
}
|
|
return NULL;
|
|
}
|