Commit dafaf135 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Max Reitz
Browse files

block/block-copy: refactor interfaces to use bytes instead of end 



We have a lot of "chunk_end - start" invocations, let's switch to
bytes/cur_bytes scheme instead.

While being here, improve check on block_copy_do_copy parameters to not
overflow when calculating nbytes and use int64_t for bytes in
block_copy for consistency.

Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: default avatarAndrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Message-Id: <20200311103004.7649-7-vsementsov@virtuozzo.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent 17187cb6

block/block-copy.c

+41 −37
Original line number Diff line number Diff line
@@ -26,12 +26,12 @@ 


static BlockCopyInFlightReq *find_conflicting_inflight_req(BlockCopyState *s,

                                                           int64_t start,

                                                           int64_t end)

                                                           int64_t bytes)

{

    BlockCopyInFlightReq *req;



    QLIST_FOREACH(req, &s->inflight_reqs, list) {

        if (end > req->start_byte && start < req->end_byte) {

        if (start + bytes > req->start && start < req->start + req->bytes) {

            return req;

        }

    }
@@ -41,21 +41,21 @@ static BlockCopyInFlightReq *find_conflicting_inflight_req(BlockCopyState *s, 


static void coroutine_fn block_copy_wait_inflight_reqs(BlockCopyState *s,

                                                       int64_t start,

                                                       int64_t end)

                                                       int64_t bytes)

{

    BlockCopyInFlightReq *req;



    while ((req = find_conflicting_inflight_req(s, start, end))) {

    while ((req = find_conflicting_inflight_req(s, start, bytes))) {

        qemu_co_queue_wait(&req->wait_queue, NULL);

    }

}



static void block_copy_inflight_req_begin(BlockCopyState *s,

                                          BlockCopyInFlightReq *req,

                                          int64_t start, int64_t end)

                                          int64_t start, int64_t bytes)

{

    req->start_byte = start;

    req->end_byte = end;

    req->start = start;

    req->bytes = bytes;

    qemu_co_queue_init(&req->wait_queue);

    QLIST_INSERT_HEAD(&s->inflight_reqs, req, list);

}
@@ -153,24 +153,28 @@ void block_copy_set_progress_meter(BlockCopyState *s, ProgressMeter *pm) 
/*

 * block_copy_do_copy

 *

 * Do copy of cluser-aligned chunk. @end is allowed to exceed s->len only to

 * cover last cluster when s->len is not aligned to clusters.

 * 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.

 *

 * Returns 0 on success.

 */

static int coroutine_fn block_copy_do_copy(BlockCopyState *s,

                                           int64_t start, int64_t end,

                                           int64_t start, int64_t bytes,

                                           bool zeroes, bool *error_is_read)

{

    int ret;

    int nbytes = MIN(end, s->len) - start;

    int64_t nbytes = MIN(start + bytes, s->len) - start;

    void *bounce_buffer = NULL;



    assert(start >= 0 && bytes > 0 && INT64_MAX - start >= bytes);

    assert(QEMU_IS_ALIGNED(start, s->cluster_size));

    assert(QEMU_IS_ALIGNED(end, s->cluster_size));

    assert(end < s->len || end == QEMU_ALIGN_UP(s->len, s->cluster_size));

    assert(QEMU_IS_ALIGNED(bytes, s->cluster_size));

    assert(start < s->len);

    assert(start + bytes <= s->len ||

           start + bytes == QEMU_ALIGN_UP(s->len, s->cluster_size));

    assert(nbytes < INT_MAX);



    if (zeroes) {

        ret = bdrv_co_pwrite_zeroes(s->target, start, nbytes, s->write_flags &
@@ -354,11 +358,10 @@ int64_t block_copy_reset_unallocated(BlockCopyState *s, 
}



int coroutine_fn block_copy(BlockCopyState *s,

                            int64_t start, uint64_t bytes,

                            int64_t start, int64_t bytes,

                            bool *error_is_read)

{

    int ret = 0;

    int64_t end = bytes + start; /* bytes */

    BlockCopyInFlightReq req;



    /*
@@ -369,32 +372,32 @@ int coroutine_fn block_copy(BlockCopyState *s, 
           bdrv_get_aio_context(s->target->bs));



    assert(QEMU_IS_ALIGNED(start, s->cluster_size));

    assert(QEMU_IS_ALIGNED(end, s->cluster_size));

    assert(QEMU_IS_ALIGNED(bytes, s->cluster_size));



    block_copy_wait_inflight_reqs(s, start, bytes);

    block_copy_inflight_req_begin(s, &req, start, end);

    block_copy_inflight_req_begin(s, &req, start, bytes);



    while (start < end) {

        int64_t next_zero, chunk_end, status_bytes;

    while (bytes) {

        int64_t next_zero, cur_bytes, status_bytes;



        if (!bdrv_dirty_bitmap_get(s->copy_bitmap, start)) {

            trace_block_copy_skip(s, start);

            start += s->cluster_size;

            bytes -= s->cluster_size;

            continue; /* already copied */

        }



        chunk_end = MIN(end, start + s->copy_size);

        cur_bytes = MIN(bytes, s->copy_size);



        next_zero = bdrv_dirty_bitmap_next_zero(s->copy_bitmap, start,

                                                chunk_end - start);

                                                cur_bytes);

        if (next_zero >= 0) {

            assert(next_zero > start); /* start is dirty */

            assert(next_zero < chunk_end); /* no need to do MIN() */

            chunk_end = next_zero;

            assert(next_zero < start + cur_bytes); /* no need to do MIN() */

            cur_bytes = next_zero - start;

        }



        ret = block_copy_block_status(s, start, chunk_end - start,

                                      &status_bytes);

        ret = block_copy_block_status(s, start, cur_bytes, &status_bytes);

        if (s->skip_unallocated && !(ret & BDRV_BLOCK_ALLOCATED)) {

            bdrv_reset_dirty_bitmap(s->copy_bitmap, start, status_bytes);

            progress_set_remaining(s->progress,
@@ -402,30 +405,31 @@ int coroutine_fn block_copy(BlockCopyState *s, 
                                   s->in_flight_bytes);

            trace_block_copy_skip_range(s, start, status_bytes);

            start += status_bytes;

            bytes -= status_bytes;

            continue;

        }



        chunk_end = MIN(chunk_end, start + status_bytes);

        cur_bytes = MIN(cur_bytes, status_bytes);



        trace_block_copy_process(s, start);



        bdrv_reset_dirty_bitmap(s->copy_bitmap, start, chunk_end - start);

        s->in_flight_bytes += chunk_end - start;

        bdrv_reset_dirty_bitmap(s->copy_bitmap, start, cur_bytes);

        s->in_flight_bytes += cur_bytes;



        co_get_from_shres(s->mem, chunk_end - start);

        ret = block_copy_do_copy(s, start, chunk_end, ret & BDRV_BLOCK_ZERO,

        co_get_from_shres(s->mem, cur_bytes);

        ret = block_copy_do_copy(s, start, cur_bytes, ret & BDRV_BLOCK_ZERO,

                                 error_is_read);

        co_put_to_shres(s->mem, chunk_end - start);

        s->in_flight_bytes -= chunk_end - start;

        co_put_to_shres(s->mem, cur_bytes);

        s->in_flight_bytes -= cur_bytes;

        if (ret < 0) {

            bdrv_set_dirty_bitmap(s->copy_bitmap, start, chunk_end - start);

            bdrv_set_dirty_bitmap(s->copy_bitmap, start, cur_bytes);

            break;

        }



        progress_work_done(s->progress, chunk_end - start);

        s->progress_bytes_callback(chunk_end - start, s->progress_opaque);

        start = chunk_end;

        ret = 0;

        progress_work_done(s->progress, cur_bytes);

        s->progress_bytes_callback(cur_bytes, s->progress_opaque);

        start += cur_bytes;

        bytes -= cur_bytes;

    }



    block_copy_inflight_req_end(&req);

include/block/block-copy.h

+3 −3
Original line number Diff line number Diff line
@@ -19,8 +19,8 @@ 
#include "qemu/co-shared-resource.h"



typedef struct BlockCopyInFlightReq {

    int64_t start_byte;

    int64_t end_byte;

    int64_t start;

    int64_t bytes;

    QLIST_ENTRY(BlockCopyInFlightReq) list;

    CoQueue wait_queue; /* coroutines blocked on this request */

} BlockCopyInFlightReq;
@@ -85,7 +85,7 @@ void block_copy_state_free(BlockCopyState *s); 
int64_t block_copy_reset_unallocated(BlockCopyState *s,

                                     int64_t offset, int64_t *count);



int coroutine_fn block_copy(BlockCopyState *s, int64_t start, uint64_t bytes,

int coroutine_fn block_copy(BlockCopyState *s, int64_t start, int64_t bytes,

                            bool *error_is_read);



#endif /* BLOCK_COPY_H */