On 10/29/2010 7:27 AM, Czarnowska, Anna wrote:
From 30aa06f20497fadf58990685ecc0554ffce21f25 Mon Sep 17 00:00:00 2001
From: Marcin Labun<marcin.labun@xxxxxxxxx>
Date: Thu, 30 Sep 2010 05:00:57 +0200
Subject: [PATCH 16/17] IMSM: Fix problem in mdmon monitor of using removed disk from in imsm container.
Manager thread shall pass the information to monitor thread (mdmon)
that some devices are removed from container. Otherwise, monitor (mdmon)
might use such devices (spares) to rebuild the array that has gone degraded.
This problem happens for imsm containers, since a list of the container disks
is maintained in intel_super structure. When array goes degraded, the list is
searched to find a spare disks to start rebuild.
Without this fix the rebuild could be stared on the spare device that was
a member of the container, but has been removed from it.
Yes, definitely a bug.
New super type function handler has been introduced to prepare metadata
format specific information about removed devices.
int (*remove_from_super)(struct supertype *st, mdu_disk_info_t *dinfo,
int fd);
The message prepared in remove_from_super is later processed
by proceess_update handler in monitor thread.
Signed-off-by: Marcin Labun<marcin.labun@xxxxxxxxx>
---
managemon.c | 38 ++++++++++++++
mdadm.h | 7 ++-
super-intel.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++-----------
3 files changed, 173 insertions(+), 31 deletions(-)
diff --git a/managemon.c b/managemon.c
index bab0397..8ab2746 100644
--- a/managemon.c
+++ b/managemon.c
@@ -297,6 +297,43 @@ static void add_disk_to_container(struct supertype *st, struct mdinfo *sd)
st->update_tail = NULL;
}
+/*
+ * Create and queue update structure about the removed disks.
+ * The update is prepared by super type handler and passed to the monitor
+ * thread.
+ */
+static void remove_disk_from_container(struct supertype *st, struct mdinfo *sd)
+{
+ int dfd;
+ char nm[20];
+ struct metadata_update *update = NULL;
+ mdu_disk_info_t dk = {
+ .number = -1,
+ .major = sd->disk.major,
+ .minor = sd->disk.minor,
+ .raid_disk = -1,
+ .state = 0,
+ };
+ /* nothing to do if super type handler does not support
+ * remove disk primitive
+ */
+ if (!st->ss->remove_from_super)
+ return;
+ dprintf("%s: remove %d:%d to container\n",
+ __func__, sd->disk.major, sd->disk.minor);
+
+ sprintf(nm, "%d:%d", sd->disk.major, sd->disk.minor);
+ dfd = dev_open(nm, O_RDWR);
+ if (dfd< 0)
+ return;
+
+ st->update_tail =&update;
+ st->ss->remove_from_super(st,&dk, dfd);
+ st->ss->write_init_super(st);
+ queue_metadata_update(update);
Since we do not update the metadata can we just lazily queue an modified
imsm_delete() update the next time we call activate_spare() and find the
spare removed? That way it is just garbage collection without this new
infrastructure that gives the appearance we are writing metadata when
removing a spare.
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