On Sun, Nov 14, 2021 at 08:55:19PM -0800, Luis Chamberlain wrote:
Please read the commit log. It's a trap.
A hint to which patches you actually expect to see merged in first would
be more than welcome...
On Sun, Nov 14, 2021, 7:12 PM Sasha Levin <sashal@xxxxxxxxxx> wrote:
This is a note to let you know that I've just added the patch titled
floppy: fix add_disk() assumption on exit due to new developments
to the 5.14-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:
floppy-fix-add_disk-assumption-on-exit-due-to-new-de.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d42f61d25d253c5de5d6d3941bae5cfdb24c169f
Author: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Date: Mon Sep 27 15:02:50 2021 -0700
floppy: fix add_disk() assumption on exit due to new developments
[ Upstream commit 2598a2bb357d64baaa94368133ddbc900b9eb246 ]
After the patch titled "floppy: use blk_mq_alloc_disk and
blk_cleanup_disk" the floppy driver was modified to allocate
the blk_mq_alloc_disk() which allocates the disk with the
queue. This is further clarified later with the patch titled
"block: remove alloc_disk and alloc_disk_node". This clarifies
that:
Most drivers should use and have been converted to use
blk_alloc_disk and blk_mq_alloc_disk. Only the scsi
ULPs and dasd still allocate a disk separately from the
request_queue so don't bother with convenience macros for
something that should not see significant new users and
remove these wrappers.
And then we have the patch titled, "block: hold a request_queue
reference for the lifetime of struct gendisk" which ensures
that a queue is *always* present for sure during the entire
lifetime of a disk.
In the floppy driver's case then the disk always comes with the
queue. So even if even if the queue was cleaned up on exit, putting
the disk *is* still required, and likewise, blk_cleanup_queue() on
a null queue should not happen now as disk->queue is valid from
disk allocation time on.
Automatic backport code scrapers should hopefully not cherry pick
this patch as a stable fix candidate without full due dilligence to
ensure all the work done on the block layer to make this happen is
merged first.
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Link:
https://lore.kernel.org/r/20210927220302.1073499-3-mcgrof@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index fef79ea52e3ed..3e6390fd5f2be 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4953,19 +4953,6 @@ static void __exit floppy_module_exit(void)
blk_cleanup_queue(disks[drive][i]->queue);
}
blk_mq_free_tag_set(&tag_sets[drive]);
-
- /*
- * These disks have not called add_disk(). Don't put down
- * queue reference in put_disk().
- */
- if (!(allowed_drive_mask & (1 << drive)) ||
- fdc_state[FDC(drive)].version == FDC_NONE) {
- for (i = 0; i < ARRAY_SIZE(floppy_type); i++) {
- if (disks[drive][i])
- disks[drive][i]->queue = NULL;
- }
- }
-
for (i = 0; i < ARRAY_SIZE(floppy_type); i++) {
if (disks[drive][i])
put_disk(disks[drive][i]);
--
Thanks,
Sasha