#include "qemu/error-report.h"
#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
-#define SLICE_TIME 100000000ULL /* ns */
typedef struct BackupBlockJob {
BlockJob common;
/* bitmap for sync=incremental */
BdrvDirtyBitmap *sync_bitmap;
MirrorSyncMode sync_mode;
- RateLimit limit;
BlockdevOnError on_source_error;
BlockdevOnError on_target_error;
CoRwlock flush_rwlock;
+ uint64_t len;
uint64_t bytes_read;
- unsigned long *done_bitmap;
int64_t cluster_size;
bool compress;
NotifierWithReturn before_write;
QLIST_HEAD(, CowRequest) inflight_reqs;
+
+ HBitmap *copy_bitmap;
+ bool use_copy_range;
+ int64_t copy_range_size;
+
+ bool serialize_target_writes;
} BackupBlockJob;
+static const BlockJobDriver backup_job_driver;
+
/* See if in-flight requests overlap and wait for them to complete */
static void coroutine_fn wait_for_overlapping_requests(BackupBlockJob *job,
int64_t start,
qemu_co_queue_restart_all(&req->wait_queue);
}
+/* Copy range to target with a bounce buffer and return the bytes copied. If
+ * error occurred, return a negative error number */
+static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job,
+ int64_t start,
+ int64_t end,
+ bool is_write_notifier,
+ bool *error_is_read,
+ void **bounce_buffer)
+{
+ int ret;
+ struct iovec iov;
+ QEMUIOVector qiov;
+ BlockBackend *blk = job->common.blk;
+ int nbytes;
+ int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
+ int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
+
+ hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);
+ nbytes = MIN(job->cluster_size, job->len - start);
+ if (!*bounce_buffer) {
+ *bounce_buffer = blk_blockalign(blk, job->cluster_size);
+ }
+ iov.iov_base = *bounce_buffer;
+ iov.iov_len = nbytes;
+ qemu_iovec_init_external(&qiov, &iov, 1);
+
+ ret = blk_co_preadv(blk, start, qiov.size, &qiov, read_flags);
+ if (ret < 0) {
+ trace_backup_do_cow_read_fail(job, start, ret);
+ if (error_is_read) {
+ *error_is_read = true;
+ }
+ goto fail;
+ }
+
+ if (qemu_iovec_is_zero(&qiov)) {
+ ret = blk_co_pwrite_zeroes(job->target, start,
+ qiov.size, write_flags | BDRV_REQ_MAY_UNMAP);
+ } else {
+ ret = blk_co_pwritev(job->target, start,
+ qiov.size, &qiov, write_flags |
+ (job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0));
+ }
+ if (ret < 0) {
+ trace_backup_do_cow_write_fail(job, start, ret);
+ if (error_is_read) {
+ *error_is_read = false;
+ }
+ goto fail;
+ }
+
+ return nbytes;
+fail:
+ hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);
+ return ret;
+
+}
+
+/* Copy range to target and return the bytes copied. If error occurred, return a
+ * negative error number. */
+static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
+ int64_t start,
+ int64_t end,
+ bool is_write_notifier)
+{
+ int ret;
+ int nr_clusters;
+ BlockBackend *blk = job->common.blk;
+ int nbytes;
+ int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
+ int write_flags = job->serialize_target_writes ? BDRV_REQ_SERIALISING : 0;
+
+ assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
+ nbytes = MIN(job->copy_range_size, end - start);
+ nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
+ hbitmap_reset(job->copy_bitmap, start / job->cluster_size,
+ nr_clusters);
+ ret = blk_co_copy_range(blk, start, job->target, start, nbytes,
+ read_flags, write_flags);
+ if (ret < 0) {
+ trace_backup_do_cow_copy_range_fail(job, start, ret);
+ hbitmap_set(job->copy_bitmap, start / job->cluster_size,
+ nr_clusters);
+ return ret;
+ }
+
+ return nbytes;
+}
+
static int coroutine_fn backup_do_cow(BackupBlockJob *job,
int64_t offset, uint64_t bytes,
bool *error_is_read,
bool is_write_notifier)
{
- BlockBackend *blk = job->common.blk;
CowRequest cow_request;
- struct iovec iov;
- QEMUIOVector bounce_qiov;
- void *bounce_buffer = NULL;
int ret = 0;
int64_t start, end; /* bytes */
- int n; /* bytes */
+ void *bounce_buffer = NULL;
qemu_co_rwlock_rdlock(&job->flush_rwlock);
wait_for_overlapping_requests(job, start, end);
cow_request_begin(&cow_request, job, start, end);
- for (; start < end; start += job->cluster_size) {
- if (test_bit(start / job->cluster_size, job->done_bitmap)) {
+ while (start < end) {
+ if (!hbitmap_get(job->copy_bitmap, start / job->cluster_size)) {
trace_backup_do_cow_skip(job, start);
+ start += job->cluster_size;
continue; /* already copied */
}
trace_backup_do_cow_process(job, start);
- n = MIN(job->cluster_size, job->common.len - start);
-
- if (!bounce_buffer) {
- bounce_buffer = blk_blockalign(blk, job->cluster_size);
- }
- iov.iov_base = bounce_buffer;
- iov.iov_len = n;
- qemu_iovec_init_external(&bounce_qiov, &iov, 1);
-
- ret = blk_co_preadv(blk, start, bounce_qiov.size, &bounce_qiov,
- is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);
- if (ret < 0) {
- trace_backup_do_cow_read_fail(job, start, ret);
- if (error_is_read) {
- *error_is_read = true;
+ if (job->use_copy_range) {
+ ret = backup_cow_with_offload(job, start, end, is_write_notifier);
+ if (ret < 0) {
+ job->use_copy_range = false;
}
- goto out;
}
-
- if (buffer_is_zero(iov.iov_base, iov.iov_len)) {
- ret = blk_co_pwrite_zeroes(job->target, start,
- bounce_qiov.size, BDRV_REQ_MAY_UNMAP);
- } else {
- ret = blk_co_pwritev(job->target, start,
- bounce_qiov.size, &bounce_qiov,
- job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+ if (!job->use_copy_range) {
+ ret = backup_cow_with_bounce_buffer(job, start, end, is_write_notifier,
+ error_is_read, &bounce_buffer);
}
if (ret < 0) {
- trace_backup_do_cow_write_fail(job, start, ret);
- if (error_is_read) {
- *error_is_read = false;
- }
- goto out;
+ break;
}
- set_bit(start / job->cluster_size, job->done_bitmap);
-
/* Publish progress, guest I/O counts as progress too. Note that the
* offset field is an opaque progress value, it is not a disk offset.
*/
- job->bytes_read += n;
- job->common.offset += n;
+ start += ret;
+ job->bytes_read += ret;
+ job_progress_update(&job->common.job, ret);
+ ret = 0;
}
-out:
if (bounce_buffer) {
qemu_vfree(bounce_buffer);
}
return backup_do_cow(job, req->offset, req->bytes, NULL, true);
}
-static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp)
-{
- BackupBlockJob *s = container_of(job, BackupBlockJob, common);
-
- if (speed < 0) {
- error_setg(errp, QERR_INVALID_PARAMETER, "speed");
- return;
- }
- ratelimit_set_speed(&s->limit, speed, SLICE_TIME);
-}
-
static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
{
BdrvDirtyBitmap *bm;
BlockDriverState *bs = blk_bs(job->common.blk);
- if (ret < 0 || block_job_is_cancelled(&job->common)) {
+ if (ret < 0) {
/* Merge the successor back into the parent, delete nothing. */
bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
assert(bm);
}
}
-static void backup_commit(BlockJob *job)
+static void backup_commit(Job *job)
{
- BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
if (s->sync_bitmap) {
backup_cleanup_sync_bitmap(s, 0);
}
}
-static void backup_abort(BlockJob *job)
+static void backup_abort(Job *job)
{
- BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
if (s->sync_bitmap) {
backup_cleanup_sync_bitmap(s, -1);
}
}
-static void backup_clean(BlockJob *job)
+static void backup_clean(Job *job)
{
- BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
assert(s->target);
blk_unref(s->target);
s->target = NULL;
BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
int64_t len;
- assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+ assert(block_job_driver(job) == &backup_job_driver);
if (backup_job->sync_mode != MIRROR_SYNC_MODE_NONE) {
error_setg(errp, "The backup job only supports block checkpoint in"
return;
}
- len = DIV_ROUND_UP(backup_job->common.len, backup_job->cluster_size);
- bitmap_zero(backup_job->done_bitmap, len);
+ len = DIV_ROUND_UP(backup_job->len, backup_job->cluster_size);
+ hbitmap_set(backup_job->copy_bitmap, 0, len);
}
void backup_wait_for_overlapping_requests(BlockJob *job, int64_t offset,
BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
int64_t start, end;
- assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+ assert(block_job_driver(job) == &backup_job_driver);
start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
BackupBlockJob *backup_job = container_of(job, BackupBlockJob, common);
int64_t start, end;
- assert(job->driver->job_type == BLOCK_JOB_TYPE_BACKUP);
+ assert(block_job_driver(job) == &backup_job_driver);
start = QEMU_ALIGN_DOWN(offset, backup_job->cluster_size);
end = QEMU_ALIGN_UP(offset + bytes, backup_job->cluster_size);
int ret;
} BackupCompleteData;
-static void backup_complete(BlockJob *job, void *opaque)
+static void backup_complete(Job *job, void *opaque)
{
BackupCompleteData *data = opaque;
- block_job_completed(job, data->ret);
+ job_completed(job, data->ret, NULL);
g_free(data);
}
static bool coroutine_fn yield_and_check(BackupBlockJob *job)
{
- if (block_job_is_cancelled(&job->common)) {
+ uint64_t delay_ns;
+
+ if (job_is_cancelled(&job->common.job)) {
return true;
}
- /* we need to yield so that bdrv_drain_all() returns.
- * (without, VM does not reboot)
- */
- if (job->common.speed) {
- uint64_t delay_ns = ratelimit_calculate_delay(&job->limit,
- job->bytes_read);
- job->bytes_read = 0;
- block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, delay_ns);
- } else {
- block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, 0);
- }
+ /* We need to yield even for delay_ns = 0 so that bdrv_drain_all() can
+ * return. Without a yield, the VM would not reboot. */
+ delay_ns = block_job_ratelimit_get_delay(&job->common, job->bytes_read);
+ job->bytes_read = 0;
+ job_sleep_ns(&job->common.job, delay_ns);
- if (block_job_is_cancelled(&job->common)) {
+ if (job_is_cancelled(&job->common.job)) {
return true;
}
static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
{
+ int ret;
bool error_is_read;
- int ret = 0;
- int clusters_per_iter;
- uint32_t granularity;
- int64_t offset;
int64_t cluster;
- int64_t end;
- int64_t last_cluster = -1;
- BdrvDirtyBitmapIter *dbi;
+ HBitmapIter hbi;
- granularity = bdrv_dirty_bitmap_granularity(job->sync_bitmap);
- clusters_per_iter = MAX((granularity / job->cluster_size), 1);
- dbi = bdrv_dirty_iter_new(job->sync_bitmap);
+ hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
+ while ((cluster = hbitmap_iter_next(&hbi, true)) != -1) {
+ do {
+ if (yield_and_check(job)) {
+ return 0;
+ }
+ ret = backup_do_cow(job, cluster * job->cluster_size,
+ job->cluster_size, &error_is_read, false);
+ if (ret < 0 && backup_error_action(job, error_is_read, -ret) ==
+ BLOCK_ERROR_ACTION_REPORT)
+ {
+ return ret;
+ }
+ } while (ret < 0);
+ }
+
+ return 0;
+}
- /* Find the next dirty sector(s) */
- while ((offset = bdrv_dirty_iter_next(dbi)) >= 0) {
- cluster = offset / job->cluster_size;
+/* init copy_bitmap from sync_bitmap */
+static void backup_incremental_init_copy_bitmap(BackupBlockJob *job)
+{
+ BdrvDirtyBitmapIter *dbi;
+ int64_t offset;
+ int64_t end = DIV_ROUND_UP(bdrv_dirty_bitmap_size(job->sync_bitmap),
+ job->cluster_size);
- /* Fake progress updates for any clusters we skipped */
- if (cluster != last_cluster + 1) {
- job->common.offset += ((cluster - last_cluster - 1) *
- job->cluster_size);
+ dbi = bdrv_dirty_iter_new(job->sync_bitmap);
+ while ((offset = bdrv_dirty_iter_next(dbi)) != -1) {
+ int64_t cluster = offset / job->cluster_size;
+ int64_t next_cluster;
+
+ offset += bdrv_dirty_bitmap_granularity(job->sync_bitmap);
+ if (offset >= bdrv_dirty_bitmap_size(job->sync_bitmap)) {
+ hbitmap_set(job->copy_bitmap, cluster, end - cluster);
+ break;
}
- for (end = cluster + clusters_per_iter; cluster < end; cluster++) {
- do {
- if (yield_and_check(job)) {
- goto out;
- }
- ret = backup_do_cow(job, cluster * job->cluster_size,
- job->cluster_size, &error_is_read,
- false);
- if ((ret < 0) &&
- backup_error_action(job, error_is_read, -ret) ==
- BLOCK_ERROR_ACTION_REPORT) {
- goto out;
- }
- } while (ret < 0);
+ offset = bdrv_dirty_bitmap_next_zero(job->sync_bitmap, offset);
+ if (offset == -1) {
+ hbitmap_set(job->copy_bitmap, cluster, end - cluster);
+ break;
}
- /* If the bitmap granularity is smaller than the backup granularity,
- * we need to advance the iterator pointer to the next cluster. */
- if (granularity < job->cluster_size) {
- bdrv_set_dirty_iter(dbi, cluster * job->cluster_size);
+ next_cluster = DIV_ROUND_UP(offset, job->cluster_size);
+ hbitmap_set(job->copy_bitmap, cluster, next_cluster - cluster);
+ if (next_cluster >= end) {
+ break;
}
- last_cluster = cluster - 1;
+ bdrv_set_dirty_iter(dbi, next_cluster * job->cluster_size);
}
- /* Play some final catchup with the progress meter */
- end = DIV_ROUND_UP(job->common.len, job->cluster_size);
- if (last_cluster + 1 < end) {
- job->common.offset += ((end - last_cluster - 1) * job->cluster_size);
- }
+ /* TODO job_progress_set_remaining() would make more sense */
+ job_progress_update(&job->common.job,
+ job->len - hbitmap_count(job->copy_bitmap) * job->cluster_size);
-out:
bdrv_dirty_iter_free(dbi);
- return ret;
}
static void coroutine_fn backup_run(void *opaque)
BackupBlockJob *job = opaque;
BackupCompleteData *data;
BlockDriverState *bs = blk_bs(job->common.blk);
- int64_t offset;
+ int64_t offset, nb_clusters;
int ret = 0;
QLIST_INIT(&job->inflight_reqs);
qemu_co_rwlock_init(&job->flush_rwlock);
- job->done_bitmap = bitmap_new(DIV_ROUND_UP(job->common.len,
- job->cluster_size));
+ nb_clusters = DIV_ROUND_UP(job->len, job->cluster_size);
+ job_progress_set_remaining(&job->common.job, job->len);
+
+ job->copy_bitmap = hbitmap_alloc(nb_clusters, 0);
+ if (job->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
+ backup_incremental_init_copy_bitmap(job);
+ } else {
+ hbitmap_set(job->copy_bitmap, 0, nb_clusters);
+ }
+
job->before_write.notify = backup_before_write_notify;
bdrv_add_before_write_notifier(bs, &job->before_write);
if (job->sync_mode == MIRROR_SYNC_MODE_NONE) {
- while (!block_job_is_cancelled(&job->common)) {
+ /* All bits are set in copy_bitmap to allow any cluster to be copied.
+ * This does not actually require them to be copied. */
+ while (!job_is_cancelled(&job->common.job)) {
/* Yield until the job is cancelled. We just let our before_write
* notify callback service CoW requests. */
- block_job_yield(&job->common);
+ job_yield(&job->common.job);
}
} else if (job->sync_mode == MIRROR_SYNC_MODE_INCREMENTAL) {
ret = backup_run_incremental(job);
} else {
/* Both FULL and TOP SYNC_MODE's require copying.. */
- for (offset = 0; offset < job->common.len;
+ for (offset = 0; offset < job->len;
offset += job->cluster_size) {
bool error_is_read;
int alloced = 0;
/* wait until pending backup_do_cow() calls have completed */
qemu_co_rwlock_wrlock(&job->flush_rwlock);
qemu_co_rwlock_unlock(&job->flush_rwlock);
- g_free(job->done_bitmap);
+ hbitmap_free(job->copy_bitmap);
data = g_malloc(sizeof(*data));
data->ret = ret;
- block_job_defer_to_main_loop(&job->common, backup_complete, data);
+ job_defer_to_main_loop(&job->common.job, backup_complete, data);
}
static const BlockJobDriver backup_job_driver = {
- .instance_size = sizeof(BackupBlockJob),
- .job_type = BLOCK_JOB_TYPE_BACKUP,
- .start = backup_run,
- .set_speed = backup_set_speed,
- .commit = backup_commit,
- .abort = backup_abort,
- .clean = backup_clean,
+ .job_driver = {
+ .instance_size = sizeof(BackupBlockJob),
+ .job_type = JOB_TYPE_BACKUP,
+ .free = block_job_free,
+ .user_resume = block_job_user_resume,
+ .drain = block_job_drain,
+ .start = backup_run,
+ .commit = backup_commit,
+ .abort = backup_abort,
+ .clean = backup_clean,
+ },
.attached_aio_context = backup_attached_aio_context,
.drain = backup_drain,
};
BlockdevOnError on_target_error,
int creation_flags,
BlockCompletionFunc *cb, void *opaque,
- BlockJobTxn *txn, Error **errp)
+ JobTxn *txn, Error **errp)
{
int64_t len;
BlockDriverInfo bdi;
goto error;
}
- /* job->common.len is fixed, so we can't allow resize */
- job = block_job_create(job_id, &backup_job_driver, bs,
+ /* job->len is fixed, so we can't allow resize */
+ job = block_job_create(job_id, &backup_job_driver, txn, bs,
BLK_PERM_CONSISTENT_READ,
BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE |
BLK_PERM_WRITE_UNCHANGED | BLK_PERM_GRAPH_MOD,
sync_bitmap : NULL;
job->compress = compress;
+ /* Detect image-fleecing (and similar) schemes */
+ job->serialize_target_writes = bdrv_chain_contains(target, bs);
+
/* If there is no backing file on the target, we cannot rely on COW if our
* backup cluster size is smaller than the target cluster size. Even for
* targets with a backing file, try to avoid COW if possible. */
} else {
job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
}
+ job->use_copy_range = true;
+ job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
+ blk_get_max_transfer(job->target));
+ job->copy_range_size = MAX(job->cluster_size,
+ QEMU_ALIGN_UP(job->copy_range_size,
+ job->cluster_size));
/* Required permissions are already taken with target's blk_new() */
block_job_add_bdrv(&job->common, "target", target, 0, BLK_PERM_ALL,
&error_abort);
- job->common.len = len;
- block_job_txn_add_job(txn, &job->common);
+ job->len = len;
return &job->common;
bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL);
}
if (job) {
- backup_clean(&job->common);
- block_job_early_fail(&job->common);
+ backup_clean(&job->common.job);
+ job_early_fail(&job->common.job);
}
return NULL;
projects / qemu.git / blobdiff