Commit 06c3916b authored by Wen Congyang's avatar Wen Congyang Committed by Jeff Cody
Browse files

Backup: don't do copy-on-read in before_write_notifier 



We will copy data in before_write_notifier to do backup.
It is a nested I/O request, so we cannot do copy-on-read.

The steps to reproduce it:
1. -drive copy-on-read=on,...  // qemu option
2. drive_backup -f disk0 /path_to_backup.img // monitor command

Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Tested-by: default avatarJeff Cody <jcody@redhat.com>
Message-id: 1441682913-14320-3-git-send-email-wency@cn.fujitsu.com
Signed-off-by: default avatarJeff Cody <jcody@redhat.com>
parent 9568b511

block/backup.c

+14 −6
Original line number Diff line number Diff line
@@ -89,7 +89,8 @@ static void cow_request_end(CowRequest *req) 


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;
@@ -129,8 +130,14 @@ static int coroutine_fn backup_do_cow(BlockDriverState *bs, 
        iov.iov_len = n * BDRV_SECTOR_SIZE;

        qemu_iovec_init_external(&bounce_qiov, &iov, 1);



        if (is_write_notifier) {

            ret = bdrv_co_no_copy_on_readv(bs,

                                           start * BACKUP_SECTORS_PER_CLUSTER,

                                           n, &bounce_qiov);

        } else {

            ret = bdrv_co_readv(bs, start * BACKUP_SECTORS_PER_CLUSTER, n,

                                &bounce_qiov);

        }

        if (ret < 0) {

            trace_backup_do_cow_read_fail(job, start, ret);

            if (error_is_read) {
@@ -190,7 +197,7 @@ static int coroutine_fn backup_before_write_notify( 
    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)
@@ -303,7 +310,8 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job) 
                    return ret;

                }

                ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER,

                                    BACKUP_SECTORS_PER_CLUSTER, &error_is_read);

                                    BACKUP_SECTORS_PER_CLUSTER, &error_is_read,

                                    false);

                if ((ret < 0) &&

                    backup_error_action(job, error_is_read, -ret) ==

                    BLOCK_ERROR_ACTION_REPORT) {
@@ -408,7 +416,7 @@ static void coroutine_fn backup_run(void *opaque) 
            }

            /* 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);

                    BACKUP_SECTORS_PER_CLUSTER, &error_is_read, false);

            if (ret < 0) {

                /* Depending on error action, fail now or retry cluster */

                BlockErrorAction action =