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Subject[ 02/70] floppy: Cleanup disk->queue before caling put_disk() if add_disk() was never called
3.2-stable review patch.  If anyone has any objections, please let me know.

------------------
From: Vivek Goyal <vgoyal@redhat.com>

commit 3f9a5aabd0a9fe0e0cd308506f48963d79169aa7 upstream.

add_disk() takes gendisk reference on request queue. If driver failed during
initialization and never called add_disk() then that extra reference is not
taken. That reference is put in put_disk(). floppy driver allocates the
disk, allocates queue, sets disk->queue and then relizes that floppy
controller is not present. It tries to tear down everything and tries to
put a reference down in put_disk() which was never taken.

In such error cases cleanup disk->queue before calling put_disk() so that
we never try to put down a reference which was never taken in first place.

Reported-and-tested-by: Suresh Jayaraman <sjayaraman@suse.com>
Tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/block/floppy.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 510fb10..401ba78 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4368,8 +4368,14 @@ out_unreg_blkdev:
out_put_disk:
while (dr--) {
del_timer_sync(&motor_off_timer[dr]);
- if (disks[dr]->queue)
+ if (disks[dr]->queue) {
blk_cleanup_queue(disks[dr]->queue);
+ /*
+ * put_disk() is not paired with add_disk() and
+ * will put queue reference one extra time. fix it.
+ */
+ disks[dr]->queue = NULL;
+ }
put_disk(disks[dr]);
}
return err;



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