[dm-devel] [PATCH v2 07/12] kpartx: don't treat multi-linear mappings as partitions
Martin Wilck
mwilck at suse.com
Mon May 15 15:37:17 UTC 2017
kpartx -d treats any map that has a "linear" mapping into a
device as first target as a partition of this device.
This is wrong, because linear mappings may consist of
several pieces, combining multiple devices into one
(LVM logical volumes are an example of such a
mapping). Partitions have to be single-target mappings.
Fix this by returning an error in dm_type() if a map with
multiple targets is encountered. The "type" of a map with
two or more targets is a difficult concept, anyway.
test case:
truncate -s 1G test0 test1
losetup /dev/loop0 test0
losetup /dev/loop1 test1
dmsetup create <<EOF
0 1000000 linear 7:0 4096
1000000 1000000 linear 7:1 4096
EOF
kpartx -d /dev/loop0 -v
The map "join" should NOT be deleted.
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
kpartx/devmapper.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/kpartx/devmapper.c b/kpartx/devmapper.c
index 6cee120d..b714ba4e 100644
--- a/kpartx/devmapper.c
+++ b/kpartx/devmapper.c
@@ -392,10 +392,11 @@ dm_type(const char * name, char * type)
goto out;
/* Fetch 1st target */
- dm_get_next_target(dmt, NULL, &start, &length,
- &target_type, ¶ms);
-
- if (!target_type)
+ if (dm_get_next_target(dmt, NULL, &start, &length,
+ &target_type, ¶ms) != NULL)
+ /* more than one target */
+ r = -1;
+ else if (!target_type)
r = -1;
else if (!strcmp(target_type, type))
r = 1;
@@ -500,7 +501,7 @@ do_foreach_partmaps (const char * mapname, const char *uuid,
/*
* skip if devmap target is not "linear"
*/
- if (!dm_type(names->name, "linear")) {
+ if (dm_type(names->name, "linear") != 1) {
if (rd->verbose)
printf("%s: is not a linear target. Not removing\n",
names->name);
--
2.12.2
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