*
*/
-#include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
+#include "qemu/osdep.h"
#include "trace.h"
#include "block/block.h"
#include "block/block_int.h"
#include "block/blockjob.h"
+#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "qemu/ratelimit.h"
+#include "qemu/cutils.h"
+#include "sysemu/block-backend.h"
+#include "qemu/bitmap.h"
-#define BACKUP_CLUSTER_BITS 16
-#define BACKUP_CLUSTER_SIZE (1 << BACKUP_CLUSTER_BITS)
-#define BACKUP_SECTORS_PER_CLUSTER (BACKUP_CLUSTER_SIZE / BDRV_SECTOR_SIZE)
-
+#define BACKUP_CLUSTER_SIZE_DEFAULT (1 << 16)
#define SLICE_TIME 100000000ULL /* ns */
typedef struct CowRequest {
BlockdevOnError on_target_error;
CoRwlock flush_rwlock;
uint64_t sectors_read;
- HBitmap *bitmap;
+ unsigned long *done_bitmap;
+ int64_t cluster_size;
QLIST_HEAD(, CowRequest) inflight_reqs;
} BackupBlockJob;
+/* Size of a cluster in sectors, instead of bytes. */
+static inline int64_t cluster_size_sectors(BackupBlockJob *job)
+{
+ return job->cluster_size / BDRV_SECTOR_SIZE;
+}
+
/* 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,
static int coroutine_fn backup_do_cow(BlockDriverState *bs,
int64_t sector_num, int nb_sectors,
- bool *error_is_read)
+ bool *error_is_read,
+ bool is_write_notifier)
{
BackupBlockJob *job = (BackupBlockJob *)bs->job;
CowRequest cow_request;
QEMUIOVector bounce_qiov;
void *bounce_buffer = NULL;
int ret = 0;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
int64_t start, end;
int n;
qemu_co_rwlock_rdlock(&job->flush_rwlock);
- start = sector_num / BACKUP_SECTORS_PER_CLUSTER;
- end = DIV_ROUND_UP(sector_num + nb_sectors, BACKUP_SECTORS_PER_CLUSTER);
+ start = sector_num / sectors_per_cluster;
+ end = DIV_ROUND_UP(sector_num + nb_sectors, sectors_per_cluster);
trace_backup_do_cow_enter(job, start, sector_num, nb_sectors);
cow_request_begin(&cow_request, job, start, end);
for (; start < end; start++) {
- if (hbitmap_get(job->bitmap, start)) {
+ if (test_bit(start, job->done_bitmap)) {
trace_backup_do_cow_skip(job, start);
continue; /* already copied */
}
trace_backup_do_cow_process(job, start);
- n = MIN(BACKUP_SECTORS_PER_CLUSTER,
+ n = MIN(sectors_per_cluster,
job->common.len / BDRV_SECTOR_SIZE -
- start * BACKUP_SECTORS_PER_CLUSTER);
+ start * sectors_per_cluster);
if (!bounce_buffer) {
- bounce_buffer = qemu_blockalign(bs, BACKUP_CLUSTER_SIZE);
+ bounce_buffer = qemu_blockalign(bs, job->cluster_size);
}
iov.iov_base = bounce_buffer;
iov.iov_len = n * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&bounce_qiov, &iov, 1);
- ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n,
- &bounce_qiov);
+ if (is_write_notifier) {
+ ret = bdrv_co_readv_no_serialising(bs,
+ start * sectors_per_cluster,
+ n, &bounce_qiov);
+ } else {
+ ret = bdrv_co_readv(bs, start * sectors_per_cluster, n,
+ &bounce_qiov);
+ }
if (ret < 0) {
trace_backup_do_cow_read_fail(job, start, ret);
if (error_is_read) {
if (buffer_is_zero(iov.iov_base, iov.iov_len)) {
ret = bdrv_co_write_zeroes(job->target,
- start * BACKUP_SECTORS_PER_CLUSTER,
+ start * sectors_per_cluster,
n, BDRV_REQ_MAY_UNMAP);
} else {
ret = bdrv_co_writev(job->target,
- start * BACKUP_SECTORS_PER_CLUSTER, n,
+ start * sectors_per_cluster, n,
&bounce_qiov);
}
if (ret < 0) {
goto out;
}
- hbitmap_set(job->bitmap, start, 1);
+ set_bit(start, 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.
assert((req->offset & (BDRV_SECTOR_SIZE - 1)) == 0);
assert((req->bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
- return backup_do_cow(req->bs, sector_num, nb_sectors, NULL);
+ return backup_do_cow(req->bs, sector_num, nb_sectors, NULL, true);
}
static void backup_set_speed(BlockJob *job, int64_t speed, Error **errp)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common);
- bdrv_iostatus_reset(s->target);
+ if (s->target->blk) {
+ blk_iostatus_reset(s->target->blk);
+ }
+}
+
+static void backup_cleanup_sync_bitmap(BackupBlockJob *job, int ret)
+{
+ BdrvDirtyBitmap *bm;
+ BlockDriverState *bs = job->common.bs;
+
+ if (ret < 0 || block_job_is_cancelled(&job->common)) {
+ /* Merge the successor back into the parent, delete nothing. */
+ bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
+ assert(bm);
+ } else {
+ /* Everything is fine, delete this bitmap and install the backup. */
+ bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
+ assert(bm);
+ }
+}
+
+static void backup_commit(BlockJob *job)
+{
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+ if (s->sync_bitmap) {
+ backup_cleanup_sync_bitmap(s, 0);
+ }
+}
+
+static void backup_abort(BlockJob *job)
+{
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+ if (s->sync_bitmap) {
+ backup_cleanup_sync_bitmap(s, -1);
+ }
}
static const BlockJobDriver backup_job_driver = {
.job_type = BLOCK_JOB_TYPE_BACKUP,
.set_speed = backup_set_speed,
.iostatus_reset = backup_iostatus_reset,
+ .commit = backup_commit,
+ .abort = backup_abort,
};
static BlockErrorAction backup_error_action(BackupBlockJob *job,
int64_t cluster;
int64_t end;
int64_t last_cluster = -1;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
BlockDriverState *bs = job->common.bs;
HBitmapIter hbi;
granularity = bdrv_dirty_bitmap_granularity(job->sync_bitmap);
- clusters_per_iter = MAX((granularity / BACKUP_CLUSTER_SIZE), 1);
+ clusters_per_iter = MAX((granularity / job->cluster_size), 1);
bdrv_dirty_iter_init(job->sync_bitmap, &hbi);
/* Find the next dirty sector(s) */
while ((sector = hbitmap_iter_next(&hbi)) != -1) {
- cluster = sector / BACKUP_SECTORS_PER_CLUSTER;
+ cluster = sector / sectors_per_cluster;
/* Fake progress updates for any clusters we skipped */
if (cluster != last_cluster + 1) {
job->common.offset += ((cluster - last_cluster - 1) *
- BACKUP_CLUSTER_SIZE);
+ job->cluster_size);
}
for (end = cluster + clusters_per_iter; cluster < end; cluster++) {
if (yield_and_check(job)) {
return ret;
}
- ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER, &error_is_read);
+ ret = backup_do_cow(bs, cluster * sectors_per_cluster,
+ sectors_per_cluster, &error_is_read,
+ false);
if ((ret < 0) &&
backup_error_action(job, error_is_read, -ret) ==
BLOCK_ERROR_ACTION_REPORT) {
/* If the bitmap granularity is smaller than the backup granularity,
* we need to advance the iterator pointer to the next cluster. */
- if (granularity < BACKUP_CLUSTER_SIZE) {
- bdrv_set_dirty_iter(&hbi, cluster * BACKUP_SECTORS_PER_CLUSTER);
+ if (granularity < job->cluster_size) {
+ bdrv_set_dirty_iter(&hbi, cluster * sectors_per_cluster);
}
last_cluster = cluster - 1;
}
/* Play some final catchup with the progress meter */
- end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE);
+ end = DIV_ROUND_UP(job->common.len, job->cluster_size);
if (last_cluster + 1 < end) {
- job->common.offset += ((end - last_cluster - 1) * BACKUP_CLUSTER_SIZE);
+ job->common.offset += ((end - last_cluster - 1) * job->cluster_size);
}
return ret;
.notify = backup_before_write_notify,
};
int64_t start, end;
+ int64_t sectors_per_cluster = cluster_size_sectors(job);
int ret = 0;
QLIST_INIT(&job->inflight_reqs);
qemu_co_rwlock_init(&job->flush_rwlock);
start = 0;
- end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE);
+ end = DIV_ROUND_UP(job->common.len, job->cluster_size);
- job->bitmap = hbitmap_alloc(end, 0);
+ job->done_bitmap = bitmap_new(end);
- bdrv_set_enable_write_cache(target, true);
- bdrv_set_on_error(target, on_target_error, on_target_error);
- bdrv_iostatus_enable(target);
+ if (target->blk) {
+ blk_set_on_error(target->blk, on_target_error, on_target_error);
+ blk_iostatus_enable(target->blk);
+ }
bdrv_add_before_write_notifier(bs, &before_write);
/* Check to see if these blocks are already in the
* backing file. */
- for (i = 0; i < BACKUP_SECTORS_PER_CLUSTER;) {
+ for (i = 0; i < sectors_per_cluster;) {
/* bdrv_is_allocated() only returns true/false based
* on the first set of sectors it comes across that
* are are all in the same state.
* needed but at some point that is always the case. */
alloced =
bdrv_is_allocated(bs,
- start * BACKUP_SECTORS_PER_CLUSTER + i,
- BACKUP_SECTORS_PER_CLUSTER - i, &n);
+ start * sectors_per_cluster + i,
+ sectors_per_cluster - i, &n);
i += n;
if (alloced == 1 || n == 0) {
}
}
/* FULL sync mode we copy the whole drive. */
- ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER,
- BACKUP_SECTORS_PER_CLUSTER, &error_is_read);
+ ret = backup_do_cow(bs, start * sectors_per_cluster,
+ sectors_per_cluster, &error_is_read, false);
if (ret < 0) {
/* Depending on error action, fail now or retry cluster */
BlockErrorAction action =
/* 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);
- if (job->sync_bitmap) {
- BdrvDirtyBitmap *bm;
- if (ret < 0 || block_job_is_cancelled(&job->common)) {
- /* Merge the successor back into the parent, delete nothing. */
- bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL);
- assert(bm);
- } else {
- /* Everything is fine, delete this bitmap and install the backup. */
- bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL);
- assert(bm);
- }
+ if (target->blk) {
+ blk_iostatus_disable(target->blk);
}
- hbitmap_free(job->bitmap);
-
- bdrv_iostatus_disable(target);
bdrv_op_unblock_all(target, job->common.blocker);
data = g_malloc(sizeof(*data));
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
BlockCompletionFunc *cb, void *opaque,
- Error **errp)
+ BlockJobTxn *txn, Error **errp)
{
int64_t len;
+ BlockDriverInfo bdi;
+ int ret;
assert(bs);
assert(target);
if ((on_source_error == BLOCKDEV_ON_ERROR_STOP ||
on_source_error == BLOCKDEV_ON_ERROR_ENOSPC) &&
- !bdrv_iostatus_is_enabled(bs)) {
+ (!bs->blk || !blk_iostatus_is_enabled(bs->blk))) {
error_setg(errp, QERR_INVALID_PARAMETER, "on-source-error");
return;
}
goto error;
}
- bdrv_op_block_all(target, job->common.blocker);
-
job->on_source_error = on_source_error;
job->on_target_error = on_target_error;
job->target = target;
job->sync_mode = sync_mode;
job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_INCREMENTAL ?
sync_bitmap : NULL;
+
+ /* 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. */
+ ret = bdrv_get_info(job->target, &bdi);
+ if (ret < 0 && !target->backing) {
+ error_setg_errno(errp, -ret,
+ "Couldn't determine the cluster size of the target image, "
+ "which has no backing file");
+ error_append_hint(errp,
+ "Aborting, since this may create an unusable destination image\n");
+ goto error;
+ } else if (ret < 0 && target->backing) {
+ /* Not fatal; just trudge on ahead. */
+ job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT;
+ } else {
+ job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
+ }
+
+ bdrv_op_block_all(target, job->common.blocker);
job->common.len = len;
job->common.co = qemu_coroutine_create(backup_run);
+ block_job_txn_add_job(txn, &job->common);
qemu_coroutine_enter(job->common.co, job);
return;
Code Review / kvmfornfv.git / blobdiff