[CRIU] [RFC PATCH v2 4/6] populate FSTYPE__AUTO fstypes during restore

[Oleg Nesterov]

On 03/27, Oleg Nesterov wrote:
>
> +			 * all once. decode_fstype() below must find it.
>  			 */
> -			pr_warn("XXX FSTYPE__AUTO name:[%s]\n", me->fsname);
> +			__find_fstype_by_name(me->fsname, true);

OOPS, sorry, sent the wrong version. See the fixed patch below.

-------------------------------------------------------------------------------
Subject: [RFC PATCH v2 4/6] populate FSTYPE__AUTO fstypes during restore

Turn find_fstype_by_name(name) into __find_fstype_by_name(name, force_auto)
and reimplement find_fstype_by_name() as a trivial wrapper on top.

Change collect_mnt_from_image() to do __find_fstype_by_name(fsname, true)
when fstype = FSTYPE__AUTO.

TODO: Note the "#if 0" block in __find_fstype_by_name(), imo makes sense
but we don't have WARN_ON() yet.

Signed-off-by: Oleg Nesterov <oleg at redhat.com>
---
 mount.c |   26 +++++++++++++++-----------
 1 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/mount.c b/mount.c
index e05b599..e274410 100644
--- a/mount.c
+++ b/mount.c
@@ -1100,7 +1100,7 @@ static bool fstype_is_auto(const char *name)
 	return false;
 }
 
-struct fstype *find_fstype_by_name(char *fst)
+static struct fstype *__find_fstype_by_name(char *fst, bool force_auto)
 {
 	int i;
 
@@ -1116,7 +1116,7 @@ struct fstype *find_fstype_by_name(char *fst)
 		struct fstype *fstype = fstypes + i;
 
 		if (!fstype->name) {
-			if (!fstype_is_auto(fst))
+			if (!force_auto && !fstype_is_auto(fst))
 				break;
 
 			fstype->name = xstrdup(fst);
@@ -1128,9 +1128,18 @@ struct fstype *find_fstype_by_name(char *fst)
 			return fstype;
 	}
 
+#if 0
+	WARN_ON(i == ARRAY_SIZE(fstypes)); /* auto should have a room */
+	WARN_ON(force_auto);
+#endif
 	return &fstypes[0];
 }
 
+struct fstype *find_fstype_by_name(char *fst)
+{
+	return __find_fstype_by_name(fst, false);
+}
+
 static struct fstype *decode_fstype(u32 fst)
 {
 	int i;
@@ -1887,23 +1896,18 @@ static int collect_mnt_from_image(struct mount_info **pms, struct ns_id *nsid)
 		BUG_ON((me->fstype == FSTYPE__AUTO) !=
 		       (me->fsname != NULL));
 
+		/* FIXME: abort unsupported early */
 		if (me->fstype == FSTYPE__AUTO) {
 			/*
 			 * TODO: this is ugly and suboptimal. We should dump
 			 * the list of FSTYPE__AUTO fsnames and restore them
 			 * all once
 			 */
-
-			/*
-			 * XXX: just print the dumped/restored ->fsname till
-			 * the next patch.
-			 */
-			pr_warn("XXX FSTYPE__AUTO name:[%s]\n", me->fsname);
+			pm->fstype = __find_fstype_by_name(me->fsname, true);
+		} else {
+			pm->fstype = decode_fstype(me->fstype);
 		}
 
-		/* FIXME: abort unsupported early */
-		pm->fstype		= decode_fstype(me->fstype);
-
 		if (me->ext_mount) {
 			struct ext_mount *em;
 
-- 
1.5.5.1