Martchus
/
mdadm
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

FIX: Mdmon crashes after changing RAID level from 1 to 0 

Description of the bug:
Sometimes mdmon crashes after changing RAID level from 1 to 0 (takeover).

Cause of the bug:
The managemon marks an active_array for removal from monitoring
by assigning a->container to NULL value (in the "manage_member" function).
Sometimes (during stress test) it happens right when the monitor
is in the "read_and_act" function and a->container pointer is in use.
This causes the monitor crashes.

Solution:
The active array has to be marked for removal in another way
than setting NULL pointer when it can be in use.
A new field "to_remove" was added to the "active_array" structure.
It is used in the managemon to mark a container to remove
(instead of the old assigment: a->container = NULL)
and monitor checks it to determine if the array should be removed.
The field "to_remove" should be checked in some other places
to avoid managing of the array which is going to be removed.

Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
Lukasz Dorau 2011-09-01 15:10:34 +02:00 committed by NeilBrown
parent 3960e579bf
commit ba71445069
3 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
managemon.c
View File

@ -461,7 +461,7 @@ static void manage_member(struct mdstat_ent *mdstat,
if (mdstat->level) {
int level = map_name(pers, mdstat->level);
if (level == 0 || level == LEVEL_LINEAR) {
a->container = NULL;
a->to_remove = 1;
wakeup_monitor();
return;
}
@ -739,7 +739,7 @@ void manage(struct mdstat_ent *mdstat, struct supertype *container)
/* Looks like a member of this container */
for (a = container->arrays; a; a = a->next) {
if (mdstat->devnum == a->devnum) {
if (a->container)
if (a->container && a->to_remove == 0)
manage_member(mdstat, a);
break;
}

1
mdmon.h
View File

@ -28,6 +28,7 @@ struct active_array {
struct mdinfo info;
struct supertype *container;
struct active_array *next, *replaces;
int to_remove;
int action_fd;
int resync_start_fd;

8
monitor.c
View File

@ -479,7 +479,7 @@ static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
struct mdinfo *victim;
for (a = aa; a; a = a->next) {
if (!a->container)
if (!a->container || a->to_remove)
continue;
victim = find_device(a, failed->disk.major, failed->disk.minor);
if (!victim)
@ -539,7 +539,7 @@ static int wait_and_act(struct supertype *container, int nowait)
/* once an array has been deactivated we want to
* ask the manager to discard it.
*/
if (!a->container) {
if (!a->container || a->to_remove) {
if (discard_this) {
ap = &(*ap)->next;
continue;
@ -642,7 +642,7 @@ static int wait_and_act(struct supertype *container, int nowait)
/* FIXME check if device->state_fd need to be cleared?*/
signal_manager();
}
if (a->container) {
if (a->container && !a->to_remove) {
is_dirty = read_and_act(a);
rv |= 1;
dirty_arrays += is_dirty;
@ -657,7 +657,7 @@ static int wait_and_act(struct supertype *container, int nowait)
/* propagate failures across container members */
for (a = *aap; a ; a = a->next) {
if (!a->container)
if (!a->container || a->to_remove)
continue;
for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
if (mdi->curr_state & DS_FAULTY)