The patch titled
md: avoid a deadlock when removing a device from an md array via sysfs
has been added to the -mm tree. Its filename is
md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: md: avoid a deadlock when removing a device from an md array via sysfs
From: NeilBrown <[EMAIL PROTECTED]>
A device can be removed from an md array via e.g.
echo remove > /sys/block/md3/md/dev-sde/state
This will try to remove the 'dev-sde' subtree which will deadlock
since
commit e7b0d26a86943370c04d6833c6edba2a72a6e240
With this patch we run the kobject_del via schedule_work so as to
avoid the deadlock.
Cc: Alan Stern <[EMAIL PROTECTED]>
Signed-off-by: Neil Brown <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---
drivers/md/md.c | 13 ++++++++++++-
include/linux/raid/md_k.h | 1 +
2 files changed, 13 insertions(+), 1 deletion(-)
diff -puN
drivers/md/md.c~md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs
drivers/md/md.c
---
a/drivers/md/md.c~md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs
+++ a/drivers/md/md.c
@@ -1378,6 +1378,12 @@ static int bind_rdev_to_array(mdk_rdev_t
return err;
}
+static void delayed_delete(struct work_struct *ws)
+{
+ mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
+ kobject_del(&rdev->kobj);
+}
+
static void unbind_rdev_from_array(mdk_rdev_t * rdev)
{
char b[BDEVNAME_SIZE];
@@ -1390,7 +1396,12 @@ static void unbind_rdev_from_array(mdk_r
printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
- kobject_del(&rdev->kobj);
+
+ /* We need to delay this, otherwise we can deadlock when
+ * writing to 'remove' to "dev/state"
+ */
+ INIT_WORK(&rdev->del_work, delayed_delete);
+ schedule_work(&rdev->del_work);
}
/*
diff -puN
include/linux/raid/md_k.h~md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs
include/linux/raid/md_k.h
---
a/include/linux/raid/md_k.h~md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs
+++ a/include/linux/raid/md_k.h
@@ -104,6 +104,7 @@ struct mdk_rdev_s
* for reporting to userspace and
storing
* in superblock.
*/
+ struct work_struct del_work; /* used for delayed sysfs removal */
};
struct mddev_s
_
Patches currently in -mm which might be from [EMAIL PROTECTED] are
origin.patch
md-avoid-a-deadlock-when-removing-a-device-from-an-md-array-via-sysfs.patch
net-sunrpc-svcsockc-fix-a-check.patch
fix-quadratic-behavior-of-shrink_dcache_parent.patch
fix-__d_path-for-lazy-unmounts-and-make-it-unambiguous.patch
the-nfsv2-nfsv3-server-does-not-handle-zero-length-write.patch
readahead-nfsd-case.patch
drivers-mdc-use-array_size-macro-when-appropriate.patch
md-dm-reduce-stack-usage-with-stacked-block-devices.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
