At runtime (that is, during a future ssh_truncate()), the SSH session is non-blocking. However, ssh_truncate() (or rather, bdrv_truncate() in general) is not a coroutine, so this resize operation needs to block.
For ssh_create(), that is fine, too; the session is never set to non-blocking anyway. Signed-off-by: Max Reitz <mre...@redhat.com> --- block/ssh.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/ssh.c b/block/ssh.c index 964e55f7fe..ff8576f21e 100644 --- a/block/ssh.c +++ b/block/ssh.c @@ -803,17 +803,24 @@ static int ssh_file_open(BlockDriverState *bs, QDict *options, int bdrv_flags, return ret; } +/* Note: This is a blocking operation */ static int ssh_grow_file(BDRVSSHState *s, int64_t offset, Error **errp) { ssize_t ret; char c[1] = { '\0' }; + int was_blocking = libssh2_session_get_blocking(s->session); /* offset must be strictly greater than the current size so we do * not overwrite anything */ assert(offset > 0 && offset > s->attrs.filesize); + libssh2_session_set_blocking(s->session, 1); + libssh2_sftp_seek64(s->sftp_handle, offset - 1); ret = libssh2_sftp_write(s->sftp_handle, c, 1); + + libssh2_session_set_blocking(s->session, was_blocking); + if (ret < 0) { sftp_error_setg(errp, s, "Failed to grow file"); return -EIO; -- 2.14.3