Patch "dm: Fix dm_accept_partial_bio() relative to zone management commands" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    dm: Fix dm_accept_partial_bio() relative to zone management commands

to the 5.10-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:
     dm-fix-dm_accept_partial_bio-relative-to-zone-manage.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ab09eba55bea704447654e549c9f3574cf556109
Author: Damien Le Moal <damien.lemoal@xxxxxxx>
Date:   Wed May 26 06:24:54 2021 +0900

    dm: Fix dm_accept_partial_bio() relative to zone management commands
    
    [ Upstream commit 6842d264aa5205da338b6dcc6acfa2a6732558f1 ]
    
    Fix dm_accept_partial_bio() to actually check that zone management
    commands are not passed as explained in the function documentation
    comment. Also, since a zone append operation cannot be split, add
    REQ_OP_ZONE_APPEND as a forbidden command.
    
    White lines are added around the group of BUG_ON() calls to make the
    code more legible.
    
    Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
    Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 638c04f9e832..19a70f434029 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1230,8 +1230,8 @@ static int dm_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
 
 /*
  * A target may call dm_accept_partial_bio only from the map routine.  It is
- * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_RESET,
- * REQ_OP_ZONE_OPEN, REQ_OP_ZONE_CLOSE and REQ_OP_ZONE_FINISH.
+ * allowed for all bio types except REQ_PREFLUSH, REQ_OP_ZONE_* zone management
+ * operations and REQ_OP_ZONE_APPEND (zone append writes).
  *
  * dm_accept_partial_bio informs the dm that the target only wants to process
  * additional n_sectors sectors of the bio and the rest of the data should be
@@ -1261,9 +1261,13 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
 {
 	struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
 	unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;
+
 	BUG_ON(bio->bi_opf & REQ_PREFLUSH);
+	BUG_ON(op_is_zone_mgmt(bio_op(bio)));
+	BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND);
 	BUG_ON(bi_size > *tio->len_ptr);
 	BUG_ON(n_sectors > bi_size);
+
 	*tio->len_ptr -= bi_size - n_sectors;
 	bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT;
 }