#include "trace.h"
#include "qapi/error.h"
#include "block/block-copy.h"
+#include "block/block_int-io.h"
+#include "block/dirty-bitmap.h"
+#include "block/reqlist.h"
#include "sysemu/block-backend.h"
#include "qemu/units.h"
+#include "qemu/co-shared-resource.h"
#include "qemu/coroutine.h"
+#include "qemu/ratelimit.h"
#include "block/aio_task.h"
+#include "qemu/error-report.h"
+#include "qemu/memalign.h"
#define BLOCK_COPY_MAX_COPY_RANGE (16 * MiB)
#define BLOCK_COPY_MAX_BUFFER (1 * MiB)
#define BLOCK_COPY_MAX_MEM (128 * MiB)
#define BLOCK_COPY_MAX_WORKERS 64
#define BLOCK_COPY_SLICE_TIME 100000000ULL /* ns */
+#define BLOCK_COPY_CLUSTER_SIZE_DEFAULT (1 << 16)
typedef enum {
COPY_READ_WRITE_CLUSTER,
QLIST_ENTRY(BlockCopyCallState) list;
/*
- * Fields that report information about return values and erros.
+ * Fields that report information about return values and errors.
* Protected by lock in BlockCopyState.
*/
bool error_is_read;
*/
BlockCopyState *s;
BlockCopyCallState *call_state;
- int64_t offset;
/*
* @method can also be set again in the while loop of
* block_copy_dirty_clusters(), but it is never accessed concurrently
BlockCopyMethod method;
/*
- * Fields whose state changes throughout the execution
- * Protected by lock in BlockCopyState.
- */
- CoQueue wait_queue; /* coroutines blocked on this task */
- /*
- * Only protect the case of parallel read while updating @bytes
- * value in block_copy_task_shrink().
+ * Generally, req is protected by lock in BlockCopyState, Still req.offset
+ * is only set on task creation, so may be read concurrently after creation.
+ * req.bytes is changed at most once, and need only protecting the case of
+ * parallel read while updating @bytes value in block_copy_task_shrink().
*/
- int64_t bytes;
- QLIST_ENTRY(BlockCopyTask) list;
+ BlockReq req;
} BlockCopyTask;
static int64_t task_end(BlockCopyTask *task)
{
- return task->offset + task->bytes;
+ return task->req.offset + task->req.bytes;
}
typedef struct BlockCopyState {
CoMutex lock;
int64_t in_flight_bytes;
BlockCopyMethod method;
- QLIST_HEAD(, BlockCopyTask) tasks; /* All tasks from all block-copy calls */
+ BlockReqList reqs;
QLIST_HEAD(, BlockCopyCallState) calls;
/*
* skip_unallocated:
RateLimit rate_limit;
} BlockCopyState;
-/* Called with lock held */
-static BlockCopyTask *find_conflicting_task(BlockCopyState *s,
- int64_t offset, int64_t bytes)
-{
- BlockCopyTask *t;
-
- QLIST_FOREACH(t, &s->tasks, list) {
- if (offset + bytes > t->offset && offset < t->offset + t->bytes) {
- return t;
- }
- }
-
- return NULL;
-}
-
-/*
- * If there are no intersecting tasks return false. Otherwise, wait for the
- * first found intersecting tasks to finish and return true.
- *
- * Called with lock held. May temporary release the lock.
- * Return value of 0 proves that lock was NOT released.
- */
-static bool coroutine_fn block_copy_wait_one(BlockCopyState *s, int64_t offset,
- int64_t bytes)
-{
- BlockCopyTask *task = find_conflicting_task(s, offset, bytes);
-
- if (!task) {
- return false;
- }
-
- qemu_co_queue_wait(&task->wait_queue, &s->lock);
-
- return true;
-}
-
/* Called with lock held */
static int64_t block_copy_chunk_size(BlockCopyState *s)
{
bytes = QEMU_ALIGN_UP(bytes, s->cluster_size);
/* region is dirty, so no existent tasks possible in it */
- assert(!find_conflicting_task(s, offset, bytes));
+ assert(!reqlist_find_conflict(&s->reqs, offset, bytes));
bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
s->in_flight_bytes += bytes;
.task.func = block_copy_task_entry,
.s = s,
.call_state = call_state,
- .offset = offset,
- .bytes = bytes,
.method = s->method,
};
- qemu_co_queue_init(&task->wait_queue);
- QLIST_INSERT_HEAD(&s->tasks, task, list);
+ reqlist_init_req(&s->reqs, &task->req, offset, bytes);
return task;
}
int64_t new_bytes)
{
QEMU_LOCK_GUARD(&task->s->lock);
- if (new_bytes == task->bytes) {
+ if (new_bytes == task->req.bytes) {
return;
}
- assert(new_bytes > 0 && new_bytes < task->bytes);
+ assert(new_bytes > 0 && new_bytes < task->req.bytes);
- task->s->in_flight_bytes -= task->bytes - new_bytes;
+ task->s->in_flight_bytes -= task->req.bytes - new_bytes;
bdrv_set_dirty_bitmap(task->s->copy_bitmap,
- task->offset + new_bytes, task->bytes - new_bytes);
+ task->req.offset + new_bytes,
+ task->req.bytes - new_bytes);
- task->bytes = new_bytes;
- qemu_co_queue_restart_all(&task->wait_queue);
+ reqlist_shrink_req(&task->req, new_bytes);
}
static void coroutine_fn block_copy_task_end(BlockCopyTask *task, int ret)
{
QEMU_LOCK_GUARD(&task->s->lock);
- task->s->in_flight_bytes -= task->bytes;
+ task->s->in_flight_bytes -= task->req.bytes;
if (ret < 0) {
- bdrv_set_dirty_bitmap(task->s->copy_bitmap, task->offset, task->bytes);
+ bdrv_set_dirty_bitmap(task->s->copy_bitmap, task->req.offset,
+ task->req.bytes);
+ }
+ if (task->s->progress) {
+ progress_set_remaining(task->s->progress,
+ bdrv_get_dirty_count(task->s->copy_bitmap) +
+ task->s->in_flight_bytes);
}
- QLIST_REMOVE(task, list);
- progress_set_remaining(task->s->progress,
- bdrv_get_dirty_count(task->s->copy_bitmap) +
- task->s->in_flight_bytes);
- qemu_co_queue_restart_all(&task->wait_queue);
+ reqlist_remove_req(&task->req);
}
void block_copy_state_free(BlockCopyState *s)
target->bs->bl.max_transfer));
}
+void block_copy_set_copy_opts(BlockCopyState *s, bool use_copy_range,
+ bool compress)
+{
+ /* Keep BDRV_REQ_SERIALISING set (or not set) in block_copy_state_new() */
+ s->write_flags = (s->write_flags & BDRV_REQ_SERIALISING) |
+ (compress ? BDRV_REQ_WRITE_COMPRESSED : 0);
+
+ if (s->max_transfer < s->cluster_size) {
+ /*
+ * copy_range does not respect max_transfer. We don't want to bother
+ * with requests smaller than block-copy cluster size, so fallback to
+ * buffered copying (read and write respect max_transfer on their
+ * behalf).
+ */
+ s->method = COPY_READ_WRITE_CLUSTER;
+ } else if (compress) {
+ /* Compression supports only cluster-size writes and no copy-range. */
+ s->method = COPY_READ_WRITE_CLUSTER;
+ } else {
+ /*
+ * If copy range enabled, start with COPY_RANGE_SMALL, until first
+ * successful copy_range (look at block_copy_do_copy).
+ */
+ s->method = use_copy_range ? COPY_RANGE_SMALL : COPY_READ_WRITE;
+ }
+}
+
+static int64_t block_copy_calculate_cluster_size(BlockDriverState *target,
+ Error **errp)
+{
+ int ret;
+ BlockDriverInfo bdi;
+ bool target_does_cow = bdrv_backing_chain_next(target);
+
+ /*
+ * 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(target, &bdi);
+ if (ret == -ENOTSUP && !target_does_cow) {
+ /* Cluster size is not defined */
+ warn_report("The target block device doesn't provide "
+ "information about the block size and it doesn't have a "
+ "backing file. The default block size of %u bytes is "
+ "used. If the actual block size of the target exceeds "
+ "this default, the backup may be unusable",
+ BLOCK_COPY_CLUSTER_SIZE_DEFAULT);
+ return BLOCK_COPY_CLUSTER_SIZE_DEFAULT;
+ } else if (ret < 0 && !target_does_cow) {
+ 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");
+ return ret;
+ } else if (ret < 0 && target_does_cow) {
+ /* Not fatal; just trudge on ahead. */
+ return BLOCK_COPY_CLUSTER_SIZE_DEFAULT;
+ }
+
+ return MAX(BLOCK_COPY_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
+}
+
BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
- int64_t cluster_size, bool use_copy_range,
- bool compress, Error **errp)
+ const BdrvDirtyBitmap *bitmap,
+ Error **errp)
{
+ ERRP_GUARD();
BlockCopyState *s;
+ int64_t cluster_size;
BdrvDirtyBitmap *copy_bitmap;
bool is_fleecing;
+ cluster_size = block_copy_calculate_cluster_size(target->bs, errp);
+ if (cluster_size < 0) {
+ return NULL;
+ }
+
copy_bitmap = bdrv_create_dirty_bitmap(source->bs, cluster_size, NULL,
errp);
if (!copy_bitmap) {
return NULL;
}
bdrv_disable_dirty_bitmap(copy_bitmap);
+ if (bitmap) {
+ if (!bdrv_merge_dirty_bitmap(copy_bitmap, bitmap, NULL, errp)) {
+ error_prepend(errp, "Failed to merge bitmap '%s' to internal "
+ "copy-bitmap: ", bdrv_dirty_bitmap_name(bitmap));
+ bdrv_release_dirty_bitmap(copy_bitmap);
+ return NULL;
+ }
+ } else {
+ bdrv_set_dirty_bitmap(copy_bitmap, 0,
+ bdrv_dirty_bitmap_size(copy_bitmap));
+ }
/*
* If source is in backing chain of target assume that target is going to be
.copy_bitmap = copy_bitmap,
.cluster_size = cluster_size,
.len = bdrv_dirty_bitmap_size(copy_bitmap),
- .write_flags = (is_fleecing ? BDRV_REQ_SERIALISING : 0) |
- (compress ? BDRV_REQ_WRITE_COMPRESSED : 0),
+ .write_flags = (is_fleecing ? BDRV_REQ_SERIALISING : 0),
.mem = shres_create(BLOCK_COPY_MAX_MEM),
.max_transfer = QEMU_ALIGN_DOWN(
block_copy_max_transfer(source, target),
cluster_size),
};
- if (s->max_transfer < cluster_size) {
- /*
- * copy_range does not respect max_transfer. We don't want to bother
- * with requests smaller than block-copy cluster size, so fallback to
- * buffered copying (read and write respect max_transfer on their
- * behalf).
- */
- s->method = COPY_READ_WRITE_CLUSTER;
- } else if (compress) {
- /* Compression supports only cluster-size writes and no copy-range. */
- s->method = COPY_READ_WRITE_CLUSTER;
- } else {
- /*
- * If copy range enabled, start with COPY_RANGE_SMALL, until first
- * successful copy_range (look at block_copy_do_copy).
- */
- s->method = use_copy_range ? COPY_RANGE_SMALL : COPY_READ_WRITE;
- }
+ block_copy_set_copy_opts(s, false, false);
ratelimit_init(&s->rate_limit);
qemu_co_mutex_init(&s->lock);
- QLIST_INIT(&s->tasks);
+ QLIST_INIT(&s->reqs);
QLIST_INIT(&s->calls);
return s;
aio_task_pool_wait_slot(pool);
if (aio_task_pool_status(pool) < 0) {
- co_put_to_shres(task->s->mem, task->bytes);
+ co_put_to_shres(task->s->mem, task->req.bytes);
block_copy_task_end(task, -ECANCELED);
g_free(task);
return -ECANCELED;
* Do copy of cluster-aligned chunk. Requested region is allowed to exceed
* s->len only to cover last cluster when s->len is not aligned to clusters.
*
- * No sync here: nor bitmap neighter intersecting requests handling, only copy.
+ * No sync here: neither bitmap nor intersecting requests handling, only copy.
*
* @method is an in-out argument, so that copy_range can be either extended to
* a full-size buffer or disabled if the copy_range attempt fails. The output
* value of @method should be used for subsequent tasks.
* Returns 0 on success.
*/
-static int coroutine_fn block_copy_do_copy(BlockCopyState *s,
- int64_t offset, int64_t bytes,
- BlockCopyMethod *method,
- bool *error_is_read)
+static int coroutine_fn GRAPH_RDLOCK
+block_copy_do_copy(BlockCopyState *s, int64_t offset, int64_t bytes,
+ BlockCopyMethod *method, bool *error_is_read)
{
int ret;
int64_t nbytes = MIN(offset + bytes, s->len) - offset;
BlockCopyMethod method = t->method;
int ret;
- ret = block_copy_do_copy(s, t->offset, t->bytes, &method, &error_is_read);
+ WITH_GRAPH_RDLOCK_GUARD() {
+ ret = block_copy_do_copy(s, t->req.offset, t->req.bytes, &method,
+ &error_is_read);
+ }
WITH_QEMU_LOCK_GUARD(&s->lock) {
if (s->method == t->method) {
t->call_state->ret = ret;
t->call_state->error_is_read = error_is_read;
}
- } else {
- progress_work_done(s->progress, t->bytes);
+ } else if (s->progress) {
+ progress_work_done(s->progress, t->req.bytes);
}
}
- co_put_to_shres(s->mem, t->bytes);
+ co_put_to_shres(s->mem, t->req.bytes);
block_copy_task_end(t, ret);
return ret;
}
-static int block_copy_block_status(BlockCopyState *s, int64_t offset,
- int64_t bytes, int64_t *pnum)
+static coroutine_fn GRAPH_RDLOCK
+int block_copy_block_status(BlockCopyState *s, int64_t offset, int64_t bytes,
+ int64_t *pnum)
{
int64_t num;
BlockDriverState *base;
base = NULL;
}
- ret = bdrv_block_status_above(s->source->bs, base, offset, bytes, &num,
- NULL, NULL);
+ ret = bdrv_co_block_status_above(s->source->bs, base, offset, bytes, &num,
+ NULL, NULL);
if (ret < 0 || num < s->cluster_size) {
/*
* On error or if failed to obtain large enough chunk just fallback to
* Check if the cluster starting at offset is allocated or not.
* return via pnum the number of contiguous clusters sharing this allocation.
*/
-static int block_copy_is_cluster_allocated(BlockCopyState *s, int64_t offset,
- int64_t *pnum)
+static int coroutine_fn GRAPH_RDLOCK
+block_copy_is_cluster_allocated(BlockCopyState *s, int64_t offset,
+ int64_t *pnum)
{
BlockDriverState *bs = s->source->bs;
int64_t count, total_count = 0;
assert(QEMU_IS_ALIGNED(offset, s->cluster_size));
while (true) {
- ret = bdrv_is_allocated(bs, offset, bytes, &count);
+ /* protected in backup_run() */
+ ret = bdrv_co_is_allocated(bs, offset, bytes, &count);
if (ret < 0) {
return ret;
}
}
}
+void block_copy_reset(BlockCopyState *s, int64_t offset, int64_t bytes)
+{
+ QEMU_LOCK_GUARD(&s->lock);
+
+ bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
+ if (s->progress) {
+ progress_set_remaining(s->progress,
+ bdrv_get_dirty_count(s->copy_bitmap) +
+ s->in_flight_bytes);
+ }
+}
+
/*
* Reset bits in copy_bitmap starting at offset if they represent unallocated
* data in the image. May reset subsequent contiguous bits.
* @return 0 when the cluster at @offset was unallocated,
* 1 otherwise, and -ret on error.
*/
-int64_t block_copy_reset_unallocated(BlockCopyState *s,
- int64_t offset, int64_t *count)
+int64_t coroutine_fn block_copy_reset_unallocated(BlockCopyState *s,
+ int64_t offset,
+ int64_t *count)
{
int ret;
int64_t clusters, bytes;
bytes = clusters * s->cluster_size;
if (!ret) {
- qemu_co_mutex_lock(&s->lock);
- bdrv_reset_dirty_bitmap(s->copy_bitmap, offset, bytes);
- progress_set_remaining(s->progress,
- bdrv_get_dirty_count(s->copy_bitmap) +
- s->in_flight_bytes);
- qemu_co_mutex_unlock(&s->lock);
+ block_copy_reset(s, offset, bytes);
}
*count = bytes;
* Returns 1 if dirty clusters found and successfully copied, 0 if no dirty
* clusters found and -errno on failure.
*/
-static int coroutine_fn
+static int coroutine_fn GRAPH_RDLOCK
block_copy_dirty_clusters(BlockCopyCallState *call_state)
{
BlockCopyState *s = call_state->s;
trace_block_copy_skip_range(s, offset, bytes);
break;
}
- if (task->offset > offset) {
- trace_block_copy_skip_range(s, offset, task->offset - offset);
+ if (task->req.offset > offset) {
+ trace_block_copy_skip_range(s, offset, task->req.offset - offset);
}
found_dirty = true;
- ret = block_copy_block_status(s, task->offset, task->bytes,
+ ret = block_copy_block_status(s, task->req.offset, task->req.bytes,
&status_bytes);
assert(ret >= 0); /* never fail */
- if (status_bytes < task->bytes) {
+ if (status_bytes < task->req.bytes) {
block_copy_task_shrink(task, status_bytes);
}
if (qatomic_read(&s->skip_unallocated) &&
!(ret & BDRV_BLOCK_ALLOCATED)) {
block_copy_task_end(task, 0);
- trace_block_copy_skip_range(s, task->offset, task->bytes);
+ trace_block_copy_skip_range(s, task->req.offset, task->req.bytes);
offset = task_end(task);
bytes = end - offset;
g_free(task);
}
}
- ratelimit_calculate_delay(&s->rate_limit, task->bytes);
+ ratelimit_calculate_delay(&s->rate_limit, task->req.bytes);
- trace_block_copy_process(s, task->offset);
+ trace_block_copy_process(s, task->req.offset);
- co_get_from_shres(s->mem, task->bytes);
+ co_get_from_shres(s->mem, task->req.bytes);
offset = task_end(task);
bytes = end - offset;
* it means that some I/O operation failed in context of _this_ block_copy call,
* not some parallel operation.
*/
-static int coroutine_fn block_copy_common(BlockCopyCallState *call_state)
+static int coroutine_fn GRAPH_RDLOCK
+block_copy_common(BlockCopyCallState *call_state)
{
int ret;
BlockCopyState *s = call_state->s;
* Check that there is no task we still need to
* wait to complete
*/
- ret = block_copy_wait_one(s, call_state->offset,
- call_state->bytes);
+ ret = reqlist_wait_one(&s->reqs, call_state->offset,
+ call_state->bytes, &s->lock);
if (ret == 0) {
/*
* No pending tasks, but check again the bitmap in this
* between this and the critical section in
* block_copy_dirty_clusters().
*
- * block_copy_wait_one return value 0 also means that it
+ * reqlist_wait_one return value 0 also means that it
* didn't release the lock. So, we are still in the same
* critical section, not interrupted by any concurrent
* access to state.
return ret;
}
+static void coroutine_fn block_copy_async_co_entry(void *opaque)
+{
+ GRAPH_RDLOCK_GUARD();
+ block_copy_common(opaque);
+}
+
int coroutine_fn block_copy(BlockCopyState *s, int64_t start, int64_t bytes,
- bool ignore_ratelimit)
+ bool ignore_ratelimit, uint64_t timeout_ns,
+ BlockCopyAsyncCallbackFunc cb,
+ void *cb_opaque)
{
- BlockCopyCallState call_state = {
+ int ret;
+ BlockCopyCallState *call_state = g_new(BlockCopyCallState, 1);
+
+ *call_state = (BlockCopyCallState) {
.s = s,
.offset = start,
.bytes = bytes,
.ignore_ratelimit = ignore_ratelimit,
.max_workers = BLOCK_COPY_MAX_WORKERS,
+ .cb = cb,
+ .cb_opaque = cb_opaque,
};
- return block_copy_common(&call_state);
-}
+ ret = qemu_co_timeout(block_copy_async_co_entry, call_state, timeout_ns,
+ g_free);
+ if (ret < 0) {
+ assert(ret == -ETIMEDOUT);
+ block_copy_call_cancel(call_state);
+ /* call_state will be freed by running coroutine. */
+ return ret;
+ }
-static void coroutine_fn block_copy_async_co_entry(void *opaque)
-{
- block_copy_common(opaque);
+ ret = call_state->ret;
+ g_free(call_state);
+
+ return ret;
}
BlockCopyCallState *block_copy_async(BlockCopyState *s,
return s->copy_bitmap;
}
+int64_t block_copy_cluster_size(BlockCopyState *s)
+{
+ return s->cluster_size;
+}
+
void block_copy_set_skip_unallocated(BlockCopyState *s, bool skip)
{
qatomic_set(&s->skip_unallocated, skip);
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