The following changes since commit ab08440a4ee09032d1a9cb22fdcab23bc7e1c656:

Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20180702' into staging (2018-07-02 17:57:46 +0100)

git://github.com/codyprime/qemu-kvm-jtc.git tags/block-pull-request

for you to fetch changes up to 9ded4a0114968e98b41494fc035ba14f84cdf700:

backup: Use copy offloading (2018-07-02 23:23:45 -0400)

Block backup patches

Fam Zheng (3):

block: Fix parameter checking in bdrv_co_copy_range_internal

block: Honour BDRV_REQ_NO_SERIALISING in copy range

backup: Use copy offloading

block/backup.c | 150 ++++++++++++++++++++++++++++++------------

block/io.c | 35 +++++-----

block/trace-events | 1 +

include/block/block.h | 5 +-

4 files changed, 132 insertions(+), 59 deletions(-)

2.17.1

From: Fam Zheng <famz@redhat.com>

The implementation is similar to the 'qemu-img convert'. In the

beginning of the job, offloaded copy is attempted. If it fails, further

I/O will go through the existing bounce buffer code path.

Then, as Kevin pointed out, both this and qemu-img convert can benefit

from a local check if one request fails because of, for example, the

offset is beyond EOF, but another may well be accepted by the protocol

layer. This will be implemented separately.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>

Message-id: 20180703023758.14422-4-famz@redhat.com

Signed-off-by: Jeff Cody <jcody@redhat.com>

block/backup.c | 150 ++++++++++++++++++++++++++++++++-------------

block/trace-events | 1 +

2 files changed, 110 insertions(+), 41 deletions(-)

diff --git a/block/backup.c b/block/backup.c

--- a/block/backup.c

+++ b/block/backup.c

@@ -XXX,XX +XXX,XX @@ typedef struct BackupBlockJob {

QLIST_HEAD(, CowRequest) inflight_reqs;

HBitmap *copy_bitmap;

+ bool use_copy_range;

+ int64_t copy_range_size;

} BackupBlockJob;

static const BlockJobDriver backup_job_driver;

@@ -XXX,XX +XXX,XX @@ static void cow_request_end(CowRequest *req)

qemu_co_queue_restart_all(&req->wait_queue);

}

+/* Copy range to target with a bounce buffer and return the bytes copied. If

+ * error occured, 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;

+ 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,

+ 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;

+ }

+ goto fail;

+ if (qemu_iovec_is_zero(&qiov)) {

+ ret = blk_co_pwrite_zeroes(job->target, start,

+ qiov.size, BDRV_REQ_MAY_UNMAP);

+ ret = blk_co_pwritev(job->target, start,

+ qiov.size, &qiov,

+ 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 occured, 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;

+

+ 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,

+ is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0);

+ 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);

@@ -XXX,XX +XXX,XX @@ static int coroutine_fn backup_do_cow(BackupBlockJob *job,

wait_for_overlapping_requests(job, start, end);

cow_request_begin(&cow_request, job, start, end);

- for (; start < end; start += job->cluster_size) {

+ 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 */

}

- hbitmap_reset(job->copy_bitmap, start / job->cluster_size, 1);

trace_backup_do_cow_process(job, start);

- n = 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 = 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;

}

- hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);

- 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;

- }

- hbitmap_set(job->copy_bitmap, start / job->cluster_size, 1);

- goto out;

+ break;

}

/* 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_progress_update(&job->common.job, n);

+ start += ret;

+ job->bytes_read += ret;

+ job_progress_update(&job->common.job, ret);

+ ret = 0;

-out:

if (bounce_buffer) {

qemu_vfree(bounce_buffer);

@@ -XXX,XX +XXX,XX @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,

} 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,

diff --git a/block/trace-events b/block/trace-events

index XXXXXXX..XXXXXXX 100644

--- a/block/trace-events

+++ b/block/trace-events

@@ -XXX,XX +XXX,XX @@ backup_do_cow_skip(void *job, int64_t start) "job %p start %"PRId64

backup_do_cow_process(void *job, int64_t start) "job %p start %"PRId64

backup_do_cow_read_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"

backup_do_cow_write_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"

+backup_do_cow_copy_range_fail(void *job, int64_t start, int ret) "job %p start %"PRId64" ret %d"

# blockdev.c

qmp_block_job_cancel(void *job) "job %p"

2.17.1

From: Fam Zheng <famz@redhat.com>

This semantics is needed by drive-backup so implement it before using

this API there.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Fam Zheng <famz@redhat.com>

Message-id: 20180703023758.14422-3-famz@redhat.com

Signed-off-by: Jeff Cody <jcody@redhat.com>

---

block/io.c | 6 ++++--

include/block/block.h | 5 +++--

2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/block/io.c b/block/io.c

--- a/block/io.c

+++ b/block/io.c

@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,

tracked_request_begin(&dst_req, dst->bs, dst_offset,

bytes, BDRV_TRACKED_WRITE);

- wait_serialising_requests(&src_req);

- wait_serialising_requests(&dst_req);

+ if (!(flags & BDRV_REQ_NO_SERIALISING)) {

+ wait_serialising_requests(&src_req);

+ wait_serialising_requests(&dst_req);

+ }

if (recurse_src) {

ret = src->bs->drv->bdrv_co_copy_range_from(src->bs,

src, src_offset,

diff --git a/include/block/block.h b/include/block/block.h

index XXXXXXX..XXXXXXX 100644

--- a/include/block/block.h

+++ b/include/block/block.h

@@ -XXX,XX +XXX,XX @@ void bdrv_unregister_buf(BlockDriverState *bs, void *host);

* @dst: Destination child to copy data to

* @dst_offset: offset in @dst image to write data

* @bytes: number of bytes to copy

- * @flags: request flags. Must be one of:

- * 0 - actually read data from src;

+ * @flags: request flags. Supported flags:

* BDRV_REQ_ZERO_WRITE - treat the @src range as zero data and do zero

* write on @dst as if bdrv_co_pwrite_zeroes is

* called. Used to simplify caller code, or

* during BlockDriver.bdrv_co_copy_range_from()

* recursion.

+ * BDRV_REQ_NO_SERIALISING - do not serialize with other overlapping

+ * requests currently in flight.

*

* Returns: 0 if succeeded; negative error code if failed.

**/

2.17.1

From: Fam Zheng <famz@redhat.com>

src may be NULL if BDRV_REQ_ZERO_WRITE flag is set, in this case only

check dst and dst->bs. This bug was introduced when moving in the

request tracking code from bdrv_co_copy_range, in 37aec7d75eb.

This especially fixes the possible segfault when initializing src_bs

with a NULL src.

Signed-off-by: Fam Zheng <famz@redhat.com>

Message-id: 20180703023758.14422-2-famz@redhat.com

Reviewed-by: Jeff Cody <jcody@redhat.com>

Signed-off-by: Jeff Cody <jcody@redhat.com>

block/io.c | 29 +++++++++++++++--------------

1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/block/io.c b/block/io.c

--- a/block/io.c

+++ b/block/io.c

@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,

bool recurse_src)

{

BdrvTrackedRequest src_req, dst_req;

- BlockDriverState *src_bs = src->bs;

- BlockDriverState *dst_bs = dst->bs;

int ret;

- if (!src || !dst || !src->bs || !dst->bs) {

+ if (!dst || !dst->bs) {

return -ENOMEDIUM;

}

- ret = bdrv_check_byte_request(src->bs, src_offset, bytes);

- if (ret) {

- return ret;

- }

-

ret = bdrv_check_byte_request(dst->bs, dst_offset, bytes);

if (ret) {

return ret;

@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,

return bdrv_co_pwrite_zeroes(dst, dst_offset, bytes, flags);

}

+ if (!src || !src->bs) {

+ return -ENOMEDIUM;

+ }

+ ret = bdrv_check_byte_request(src->bs, src_offset, bytes);

+ if (ret) {

+ return ret;

+ }

if (!src->bs->drv->bdrv_co_copy_range_from

|| !dst->bs->drv->bdrv_co_copy_range_to

|| src->bs->encrypted || dst->bs->encrypted) {

return -ENOTSUP;

}

- bdrv_inc_in_flight(src_bs);

- bdrv_inc_in_flight(dst_bs);

- tracked_request_begin(&src_req, src_bs, src_offset,

+ bdrv_inc_in_flight(src->bs);

+ bdrv_inc_in_flight(dst->bs);

+ tracked_request_begin(&src_req, src->bs, src_offset,

bytes, BDRV_TRACKED_READ);

- tracked_request_begin(&dst_req, dst_bs, dst_offset,

+ tracked_request_begin(&dst_req, dst->bs, dst_offset,

bytes, BDRV_TRACKED_WRITE);

wait_serialising_requests(&src_req);

@@ -XXX,XX +XXX,XX @@ static int coroutine_fn bdrv_co_copy_range_internal(BdrvChild *src,

}

tracked_request_end(&src_req);

tracked_request_end(&dst_req);

- bdrv_dec_in_flight(src_bs);

- bdrv_dec_in_flight(dst_bs);

+ bdrv_dec_in_flight(src->bs);

+ bdrv_dec_in_flight(dst->bs);

return ret;

2.17.1