[PATCH 08/08] dm: fix ordering of initialization in alloc_dev()

From: Jeff Mahoney
Date: Thu Apr 13 2006 - 16:37:59 EST



In alloc_dev(), we register the device with the block layer and then
continue to initialize the device. register_disk() will have already
made the device available to userspace, and a potential race exists
with the device being opened for use and the completion of the
initialization.

This patch moves the final bits of the initialization above the disk
registration.

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
--
drivers/md/dm.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff -ruNpX ../dontdiff linux-2.6.16-staging1/drivers/md/dm.c linux-2.6.16-staging2/drivers/md/dm.c
--- linux-2.6.16-staging1/drivers/md/dm.c 2006-04-13 16:18:24.000000000 -0400
+++ linux-2.6.16-staging2/drivers/md/dm.c 2006-04-13 16:18:24.000000000 -0400
@@ -837,6 +837,10 @@ static struct mapped_device *alloc_dev(u
if (!md->disk)
goto bad4;

+ atomic_set(&md->pending, 0);
+ init_waitqueue_head(&md->wait);
+ init_waitqueue_head(&md->eventq);
+
md->disk->major = _major;
md->disk->first_minor = minor;
md->disk->fops = &dm_blk_dops;
@@ -845,10 +849,6 @@ static struct mapped_device *alloc_dev(u
sprintf(md->disk->disk_name, "dm-%d", minor);
add_disk(md->disk);

- atomic_set(&md->pending, 0);
- init_waitqueue_head(&md->wait);
- init_waitqueue_head(&md->eventq);
-
/* Populate the mapping, nobody knows we exist yet */
spin_lock(&_minor_lock);
r = idr_replace(&_minor_idr, md, minor);
-
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