From fe44dc91807eca59d0230fe828c1e2ee0c305a1e Mon Sep 17 00:00:00 2001 From: Ashijeet Acharya Date: Mon, 16 Jan 2017 17:01:53 +0530 Subject: migration: disallow migrate_add_blocker during migration If a migration is already in progress and somebody attempts to add a migration blocker, this should rightly fail. Add an errp parameter and a retcode return value to migrate_add_blocker. Signed-off-by: John Snow Signed-off-by: Ashijeet Acharya Message-Id: <1484566314-3987-5-git-send-email-ashijeetacharya@gmail.com> Reviewed-by: Dr. David Alan Gilbert Acked-by: Greg Kurz Signed-off-by: Dr. David Alan Gilbert Merged with recent 'Allow invtsc migration' change --- hw/9pfs/9p.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) (limited to 'hw/9pfs') diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index fa58877570..06b6e7ec66 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -979,6 +979,7 @@ static void coroutine_fn v9fs_attach(void *opaque) size_t offset = 7; V9fsQID qid; ssize_t err; + Error *local_err = NULL; v9fs_string_init(&uname); v9fs_string_init(&aname); @@ -1007,26 +1008,36 @@ static void coroutine_fn v9fs_attach(void *opaque) clunk_fid(s, fid); goto out; } - err = pdu_marshal(pdu, offset, "Q", &qid); - if (err < 0) { - clunk_fid(s, fid); - goto out; - } - err += offset; - memcpy(&s->root_qid, &qid, sizeof(qid)); - trace_v9fs_attach_return(pdu->tag, pdu->id, - qid.type, qid.version, qid.path); + /* * disable migration if we haven't done already. * attach could get called multiple times for the same export. */ if (!s->migration_blocker) { - s->root_fid = fid; error_setg(&s->migration_blocker, "Migration is disabled when VirtFS export path '%s' is mounted in the guest using mount_tag '%s'", s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag); - migrate_add_blocker(s->migration_blocker); + err = migrate_add_blocker(s->migration_blocker, &local_err); + if (local_err) { + error_free(local_err); + error_free(s->migration_blocker); + s->migration_blocker = NULL; + clunk_fid(s, fid); + goto out; + } + s->root_fid = fid; + } + + err = pdu_marshal(pdu, offset, "Q", &qid); + if (err < 0) { + clunk_fid(s, fid); + goto out; } + err += offset; + + memcpy(&s->root_qid, &qid, sizeof(qid)); + trace_v9fs_attach_return(pdu->tag, pdu->id, + qid.type, qid.version, qid.path); out: put_fid(pdu, fidp); out_nofid: -- cgit v1.2.3-55-g7522