Paolo Bonzini <pbonz...@redhat.com> writes:
> Error propagation is already there for socket backends, even though
> it is (and remains) incomplete because no Error is passed to the
> NonBlockingConnectHandler.
Why is that a problem?
> Add it to other protocols, simplifying
> code that tests for errors that will never happen.
>
> With all protocols understanding Error, the code can be simplified
> further by removing the return value.
>
> Before:
>
> (qemu) migrate fd:ffff
> migrate: An undefined error has occurred
> (qemu) info migrate
> (qemu)
>
> After:
>
> (qemu) migrate fd:ffff
> migrate: File descriptor named 'ffff' has not been found
> (qemu) info migrate
> capabilities: xbzrle: off
> Migration status: failed
> total time: 0 milliseconds
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> v1->v2: turn bizarre DPRINTF into an assertion failure or just
> drop it for the failure test of O_NONBLOCK. Clean up after this
> change.
>
> migration-fd.c | 19 ++++---------------
> migration-tcp.c | 13 ++-----------
> migration-unix.c | 11 ++---------
> migration.c | 17 ++++++-----------
> migration.h | 9 ++++-----
> 6 file modificati, 22 inserzioni(+), 65 rimozioni(-)
>
> diff --git a/migration-exec.c b/migration-exec.c
> index 6c97db9..5f3f4b2 100644
> --- a/migration-exec.c
> +++ b/migration-exec.c
> @@ -60,22 +60,18 @@ static int exec_close(MigrationState *s)
> return ret;
> }
>
> -int exec_start_outgoing_migration(MigrationState *s, const char *command)
> +void exec_start_outgoing_migration(MigrationState *s, const char *command,
> Error **errp)
> {
> FILE *f;
>
> f = popen(command, "w");
> if (f == NULL) {
> - DPRINTF("Unable to popen exec target\n");
> - goto err_after_popen;
> + error_setg_errno(errp, errno, "failed to popen the migration
> target");
> + return;
> }
>
> s->fd = fileno(f);
> - if (s->fd == -1) {
> - DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
> - goto err_after_open;
> - }
> -
> + assert(s->fd != -1);
Okay, because fileno() can fail only if its argument is not a valid
stream, which really shouldn't be possible here.
> socket_set_nonblock(s->fd);
>
> s->opaque = qemu_popen(f, "w");
> @@ -85,12 +81,6 @@ int exec_start_outgoing_migration(MigrationState *s, const
> char *command)
> s->write = file_write;
>
> migrate_fd_connect(s);
> - return 0;
> -
> -err_after_open:
> - pclose(f);
> -err_after_popen:
> - return -1;
> }
>
> static void exec_accept_incoming_migration(void *opaque)
> diff --git a/migration-fd.c b/migration-fd.c
> index 7335167..a7c800a 100644
> --- a/migration-fd.c
> +++ b/migration-fd.c
> @@ -73,30 +73,19 @@ static int fd_close(MigrationState *s)
> return 0;
> }
>
> -int fd_start_outgoing_migration(MigrationState *s, const char *fdname)
> +void fd_start_outgoing_migration(MigrationState *s, const char *fdname,
> Error **errp)
> {
> - s->fd = monitor_get_fd(cur_mon, fdname, NULL);
> + s->fd = monitor_get_fd(cur_mon, fdname, errp);
> if (s->fd == -1) {
> - DPRINTF("fd_migration: invalid file descriptor identifier\n");
> - goto err_after_get_fd;
> - }
> -
> - if (fcntl(s->fd, F_SETFL, O_NONBLOCK) == -1) {
> - DPRINTF("Unable to set nonblocking mode on file descriptor\n");
> - goto err_after_open;
> + return;
> }
>
> + fcntl(s->fd, F_SETFL, O_NONBLOCK);
Sure this can't fail?
> s->get_error = fd_errno;
> s->write = fd_write;
> s->close = fd_close;
>
> migrate_fd_connect(s);
> - return 0;
> -
> -err_after_open:
> - close(s->fd);
> -err_after_get_fd:
> - return -1;
> }
>
> static void fd_accept_incoming_migration(void *opaque)
[...]
