A 'faulty' drive is being removed from a container after it has been
released by an array, however there is a race there. The drive is
released asynchronously by a monitor but sometimes it doesn't happen
before container checks it. It results in a container refusing to remove
a drive as it still seems to be a part of some array.
It seems 'ping_monitor' could be a solution here to assure monitor has
had a chance to process the events, however it doesn't resolve the
problem - sometimes an array has to request a release of the drive few
times (as the array is busy) and single 'ping_monitor' call is not
sufficient. As there is no way to query monitor progress, it forces us
to retry a check several times before an error is returned.
Signed-off-by: Tomasz Majchrzak <tomasz.majchrzak@xxxxxxxxx>
---
Manage.c | 41 ++++++++++++++++++++++++++++-------------
1 file changed, 28 insertions(+), 13 deletions(-)
diff --git a/Manage.c b/Manage.c
index e2e88b8..33e343d 100644
--- a/Manage.c
+++ b/Manage.c
@@ -1125,19 +1125,34 @@ int Manage_remove(struct supertype *tst, int fd, struct mddev_dev *dv,
*/
if (rdev == 0)
ret = -1;
- else
- ret = sysfs_unique_holder(devnm, rdev);
- if (ret == 0) {
- pr_err("%s is not a member, cannot remove.\n",
- dv->devname);
- close(lfd);
- return -1;
- }
- if (ret >= 2) {
- pr_err("%s is still in use, cannot remove.\n",
- dv->devname);
- close(lfd);
- return -1;
+ else {
+ /*
+ * The drive has already been set to 'faulty', however
+ * monitor might not have had time to process it and the
+ * drive might still have an entry in the 'holders'
+ * directory. Try a few times to avoid a false error
+ */
+ int count = 20;
+
+ do {
+ ret = sysfs_unique_holder(devnm, rdev);
+ if (ret < 2)
+ break;
+ usleep(100 * 1000); /* 100ms */
+ } while (--count > 0);
+
+ if (ret == 0) {
+ pr_err("%s is not a member, cannot remove.\n",
+ dv->devname);
+ close(lfd);
+ return -1;
+ }
+ if (ret >= 2) {
+ pr_err("%s is still in use, cannot remove.\n",
+ dv->devname);
+ close(lfd);
+ return -1;
+ }
}
}
/* FIXME check that it is a current member */
--
1.8.3.1
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