From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Wilck Subject: [PATCH 04/10] kpartx: dm_remove_partmaps: support non-dm devices Date: Sat, 6 May 2017 00:05:53 +0200 Message-ID: <20170505220559.7248-5-mwilck@suse.com> References: <20170505220559.7248-1-mwilck@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170505220559.7248-1-mwilck@suse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Christophe Varoqui , Hannes Reinecke , Benjamin Marzinski Cc: dm-devel@redhat.com List-Id: dm-devel.ids Commit 3d709241 improved partition removal, but broke support for handling partitions of non-dm devices such as loop devices or RAM disks. This requires passing the dev_t of the device down to do_foreach_partmap(). Doing so, there's little use in trying to derive major/minor numbers from the "mapname" any more (which actually is the device name for non-DM devices). But we can use this to find out whether the device in question is a dm device. The test for UUID match doesn't work for non-DM devices (this shall be improved in a later patch in this series). The test for equal name of parent dev and partition is only valid for dm devices. For non-dm devices such as loop, "/dev/mapper/loop0" could, theoretically, be a partition of "/dev/loop0" (and we don't want to rely on map names). Fixes: 3d709241 "kpartx: sanitize delete partitions" Signed-off-by: Martin Wilck --- kpartx/devmapper.c | 26 +++++++++++++++++--------- kpartx/devmapper.h | 2 +- kpartx/kpartx.c | 3 ++- 3 files changed, 20 insertions(+), 11 deletions(-) diff --git a/kpartx/devmapper.c b/kpartx/devmapper.c index cf6650c6..8f48a705 100644 --- a/kpartx/devmapper.c +++ b/kpartx/devmapper.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "devmapper.h" #define UUID_PREFIX "part%d-" @@ -418,8 +419,8 @@ dm_compare_uuid(const char *mapuuid, const char *partname) return 1; if (!strncmp(partuuid, "part", 4)) { - char *p = strstr(partuuid, "mpath-"); - if (p && !strcmp(mapuuid, p)) + char *p = strchr(partuuid, '-'); + if (p && !strcmp(mapuuid, p + 1)) r = 0; } free(partuuid); @@ -432,6 +433,7 @@ struct remove_data { static int do_foreach_partmaps (const char * mapname, const char *uuid, + dev_t devt, int (*partmap_func)(const char *, void *), void *data) { @@ -443,6 +445,7 @@ do_foreach_partmaps (const char * mapname, const char *uuid, int major, minor; char dev_t[32]; int r = 1; + int is_dmdev = 1; if (!(dmt = dm_task_create(DM_DEVICE_LIST))) return 1; @@ -460,15 +463,20 @@ do_foreach_partmaps (const char * mapname, const char *uuid, goto out; } - if (dm_devn(mapname, &major, &minor)) - goto out; + if (dm_devn(mapname, &major, &minor) || + (major != major(devt) || minor != minor(devt))) + /* + * The latter could happen if a dm device "/dev/mapper/loop0" + * exits while kpartx is called on "/dev/loop0". + */ + is_dmdev = 0; - sprintf(dev_t, "%d:%d", major, minor); + sprintf(dev_t, "%d:%d", major(devt), minor(devt)); do { /* * skip our devmap */ - if (!strcmp(names->name, mapname)) + if (is_dmdev && !strcmp(names->name, mapname)) goto next; /* @@ -496,7 +504,7 @@ do_foreach_partmaps (const char * mapname, const char *uuid, /* * skip if uuids don't match */ - if (dm_compare_uuid(uuid, names->name)) { + if (is_dmdev && uuid && dm_compare_uuid(uuid, names->name)) { if (rd->verbose) printf("%s: is not a kpartx partition. Not removing\n", names->name); @@ -537,10 +545,10 @@ remove_partmap(const char *name, void *data) } int -dm_remove_partmaps (char * mapname, char *uuid, int verbose) +dm_remove_partmaps (char * mapname, char *uuid, dev_t devt, int verbose) { struct remove_data rd = { verbose }; - return do_foreach_partmaps(mapname, uuid, remove_partmap, &rd); + return do_foreach_partmaps(mapname, uuid, devt, remove_partmap, &rd); } #define FEATURE_NO_PART "no_partitions" diff --git a/kpartx/devmapper.h b/kpartx/devmapper.h index 9988ec0f..2e28c780 100644 --- a/kpartx/devmapper.h +++ b/kpartx/devmapper.h @@ -18,7 +18,7 @@ char * dm_mapname(int major, int minor); dev_t dm_get_first_dep(char *devname); char * dm_mapuuid(const char *mapname); int dm_devn (const char * mapname, int *major, int *minor); -int dm_remove_partmaps (char * mapname, char *uuid, int verbose); +int dm_remove_partmaps (char * mapname, char *uuid, dev_t devt, int verbose); int dm_no_partitions(char * mapname); #endif /* _KPARTX_DEVMAPPER_H */ diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c index e9b09492..e2056b7f 100644 --- a/kpartx/kpartx.c +++ b/kpartx/kpartx.c @@ -451,7 +451,8 @@ main(int argc, char **argv){ break; case DELETE: - r = dm_remove_partmaps(mapname, uuid, verbose); + r = dm_remove_partmaps(mapname, uuid, buf.st_rdev, + verbose); if (loopdev) { if (del_loop(loopdev)) { if (verbose) -- 2.12.2