This is a note to let you know that I've just added the patch titled
md: Fix - again - partition detection when array becomes active
to the 2.6.37-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
md-fix-again-partition-detection-when-array-becomes-active.patch
and it can be found in the queue-2.6.37 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f0b4f7e2f29af678bd9af43422c537dcb6008603 Mon Sep 17 00:00:00 2001
From: NeilBrown <[email protected]>
Date: Thu, 24 Feb 2011 17:26:41 +1100
Subject: md: Fix - again - partition detection when array becomes active
From: NeilBrown <[email protected]>
commit f0b4f7e2f29af678bd9af43422c537dcb6008603 upstream.
Revert
b821eaa572fd737faaf6928ba046e571526c36c6
and
f3b99be19ded511a1bf05a148276239d9f13eefa
When I wrote the first of these I had a wrong idea about the
lifetime of 'struct block_device'. It can disappear at any time that
the block device is not open if it falls out of the inode cache.
So relying on the 'size' recorded with it to detect when the
device size has changed and so we need to revalidate, is wrong.
Rather, we really do need the 'changed' attribute stored directly in
the mddev and set/tested as appropriate.
Without this patch, a sequence of:
mknod / open / close / unlink
(which can cause a block_device to be created and then destroyed)
will result in a rescan of the partition table and consequence removal
and addition of partitions.
Several of these in a row can get udev racing to create and unlink and
other code can get confused.
With the patch, the rescan is only performed when needed and so there
are no races.
This is suitable for any stable kernel from 2.6.35.
Reported-by: "Wojcik, Krzysztof" <[email protected]>
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/md/md.c | 22 +++++++++++++++++++++-
drivers/md/md.h | 2 ++
2 files changed, 23 insertions(+), 1 deletion(-)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4614,6 +4614,7 @@ static int do_md_run(mddev_t *mddev)
}
set_capacity(mddev->gendisk, mddev->array_sectors);
revalidate_disk(mddev->gendisk);
+ mddev->changed = 1;
kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
out:
return err;
@@ -4702,6 +4703,7 @@ static void md_clean(mddev_t *mddev)
mddev->sync_speed_min = mddev->sync_speed_max = 0;
mddev->recovery = 0;
mddev->in_sync = 0;
+ mddev->changed = 0;
mddev->degraded = 0;
mddev->safemode = 0;
mddev->bitmap_info.offset = 0;
@@ -4811,6 +4813,7 @@ static int do_md_stop(mddev_t * mddev, i
set_capacity(disk, 0);
mutex_unlock(&mddev->open_mutex);
+ mddev->changed = 1;
revalidate_disk(disk);
if (mddev->ro)
@@ -5994,7 +5997,7 @@ static int md_open(struct block_device *
atomic_inc(&mddev->openers);
mutex_unlock(&mddev->open_mutex);
- check_disk_size_change(mddev->gendisk, bdev);
+ check_disk_change(bdev);
out:
return err;
}
@@ -6009,6 +6012,21 @@ static int md_release(struct gendisk *di
return 0;
}
+
+static int md_media_changed(struct gendisk *disk)
+{
+ mddev_t *mddev = disk->private_data;
+
+ return mddev->changed;
+}
+
+static int md_revalidate(struct gendisk *disk)
+{
+ mddev_t *mddev = disk->private_data;
+
+ mddev->changed = 0;
+ return 0;
+}
static const struct block_device_operations md_fops =
{
.owner = THIS_MODULE,
@@ -6019,6 +6037,8 @@ static const struct block_device_operati
.compat_ioctl = md_compat_ioctl,
#endif
.getgeo = md_getgeo,
+ .media_changed = md_media_changed,
+ .revalidate_disk= md_revalidate,
};
static int md_thread(void * arg)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -270,6 +270,8 @@ struct mddev_s
atomic_t active; /* general refcount */
atomic_t openers; /* number of active
opens */
+ int changed; /* True if we might
need to
+ * reread partition
info */
int degraded; /* whether md should
consider
* adding a spare
*/
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.37/fix-over-zealous-flush_disk-when-changing-device-size.patch
queue-2.6.37/md-correctly-handle-probe-of-an-mdp-device.patch
queue-2.6.37/md-avoid-spinlock-problem-in-blk_throtl_exit.patch
queue-2.6.37/md-fix-again-partition-detection-when-array-becomes-active.patch
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