This patch adds the ability to create targets which are read-only to
keep from accidentally modifying the newly created device. In some cases,
mounting with -o ro still modifies the device (in the case of ext3
filesystems). I created a small patch that will do this. I have tested it
only to the point that using -a with or without -r produces the desired
effects.
Signed-off-by: Ritesh Raj Sarraf <rsarraf@xxxxxxxxxx>
Signed-off-by: Wakko Warner <wakko@xxxxxxxxxxxx>
---
kpartx/devmapper.c | 5 ++++-
kpartx/devmapper.h | 2 +-
kpartx/kpartx.c | 12 ++++++++----
3 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/kpartx/devmapper.c b/kpartx/devmapper.c
index f884511..7ebc5b6 100644
--- a/kpartx/devmapper.c
+++ b/kpartx/devmapper.c
@@ -81,7 +81,7 @@ dm_simplecmd (int task, const char *name, int no_flush, uint32_t *cookie) {
extern int
dm_addmap (int task, const char *name, const char *target,
- const char *params, uint64_t size, const char *uuid, int part,
+ const char *params, uint64_t size, int ro, const char *uuid, int part,
mode_t mode, uid_t uid, gid_t gid, uint32_t *cookie) {
int r = 0;
struct dm_task *dmt;
@@ -96,6 +96,9 @@ dm_addmap (int task, const char *name, const char *target,
if (!dm_task_add_target (dmt, 0, size, target, params))
goto addout;
+ if (ro && !dm_task_set_ro (dmt))
+ goto addout;
+
if (task == DM_DEVICE_CREATE && uuid) {
prefixed_uuid = malloc(MAX_PREFIX_LEN + strlen(uuid) + 1);
if (!prefixed_uuid) {
diff --git a/kpartx/devmapper.h b/kpartx/devmapper.h
index f8692cc..6226129 100644
--- a/kpartx/devmapper.h
+++ b/kpartx/devmapper.h
@@ -5,7 +5,7 @@
int dm_prereq (char *, int, int, int);
int dm_simplecmd (int, const char *, int, uint32_t *);
int dm_addmap (int, const char *, const char *, const char *, uint64_t,
- const char *, int, mode_t, uid_t, gid_t, uint32_t *);
+ int, const char *, int, mode_t, uid_t, gid_t, uint32_t *);
int dm_map_present (char *);
char * dm_mapname(int major, int minor);
dev_t dm_get_first_dep(char *devname);
diff --git a/kpartx/kpartx.c b/kpartx/kpartx.c
index 3d33990..f518aa0 100644
--- a/kpartx/kpartx.c
+++ b/kpartx/kpartx.c
@@ -82,7 +82,7 @@ initpts(void)
addpts("sun", read_sun_pt);
}
-static char short_opts[] = "ladgvp:t:s";
+static char short_opts[] = "rladgvp:t:s";
/* Used in gpt.c */
int force_gpt=0;
@@ -91,6 +91,7 @@ static int
usage(void) {
printf("usage : kpartx [-a|-d|-l] [-v] wholedisk\n");
printf("\t-a add partition devmappings\n");
+ printf("\t-r devmappings will be readonly\n");
printf("\t-d del partition devmappings\n");
printf("\t-l list partitions devmappings that would be added by -a\n");
printf("\t-p set device name-partition number delimiter\n");
@@ -185,7 +186,7 @@ get_hotplug_device(void)
int
main(int argc, char **argv){
- int fd, i, j, m, n, op, off, arg, c, d;
+ int fd, i, j, m, n, op, off, arg, c, d, ro=0;
struct slice all;
struct pt *ptp;
enum action what = LIST;
@@ -233,6 +234,9 @@ main(int argc, char **argv){
}
while ((arg = getopt(argc, argv, short_opts)) != EOF) switch(arg) {
+ case 'r':
+ ro=1;
+ break;
case 'g':
force_gpt=1;
break;
@@ -470,7 +474,7 @@ main(int argc, char **argv){
DM_DEVICE_RELOAD : DM_DEVICE_CREATE);
if (!dm_addmap(op, partname, DM_TARGET, params,
- slices[j].size, uuid, j+1,
+ slices[j].size, ro, uuid, j+1,
buf.st_mode & 0777, buf.st_uid,
buf.st_gid, &cookie)) {
fprintf(stderr, "create/reload failed on %s\n",
@@ -536,7 +540,7 @@ main(int argc, char **argv){
DM_DEVICE_RELOAD : DM_DEVICE_CREATE);
dm_addmap(op, partname, DM_TARGET, params,
- slices[j].size, uuid, j+1,
+ slices[j].size, ro, uuid, j+1,
buf.st_mode & 0777,
buf.st_uid, buf.st_gid,
&cookie);
--
1.7.2.3
--
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