diff options
| author | Damien Le Moal <dlemoal@kernel.org> | 2025-06-25 18:33:27 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-06-30 15:50:32 -0600 |
| commit | 409f9287dab3b53bffe8d28d883a529028aa6a42 (patch) | |
| tree | 09560c7acf305d488cc911601f3c80a78349547c | |
| parent | e549663849e5bb3b985dc2d293069f0d9747ae72 (diff) | |
dm: Check for forbidden splitting of zone write operations
DM targets must not split zone append and write operations using
dm_accept_partial_bio() as doing so is forbidden for zone append BIOs,
breaks zone append emulation using regular write BIOs and potentially
creates deadlock situations with queue freeze operations.
Modify dm_accept_partial_bio() to add missing BUG_ON() checks for all
these cases, that is, check that the BIO is a write or write zeroes
operation. This change packs all the zone related checks together under
a static_branch_unlikely(&zoned_enabled) and done only if the target is
a zoned device.
Fixes: f211268ed1f9 ("dm: Use the block layer zone append emulation")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Link: https://lore.kernel.org/r/20250625093327.548866-6-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/md/dm.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 7b277b18a8fe..ca889328fdfe 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1293,8 +1293,9 @@ out: /* * 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_* zone management - * operations, REQ_OP_ZONE_APPEND (zone append writes) and any bio serviced by - * __send_duplicate_bios(). + * operations, zone append writes (native with REQ_OP_ZONE_APPEND or emulated + * with write BIOs flagged with BIO_EMULATES_ZONE_APPEND) and any bio serviced + * by __send_duplicate_bios(). * * 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 @@ -1327,11 +1328,19 @@ void dm_accept_partial_bio(struct bio *bio, unsigned int n_sectors) unsigned int bio_sectors = bio_sectors(bio); BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO)); - BUG_ON(op_is_zone_mgmt(bio_op(bio))); - BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND); BUG_ON(bio_sectors > *tio->len_ptr); BUG_ON(n_sectors > bio_sectors); + if (static_branch_unlikely(&zoned_enabled) && + unlikely(bdev_is_zoned(bio->bi_bdev))) { + enum req_op op = bio_op(bio); + + BUG_ON(op_is_zone_mgmt(op)); + BUG_ON(op == REQ_OP_WRITE); + BUG_ON(op == REQ_OP_WRITE_ZEROES); + BUG_ON(op == REQ_OP_ZONE_APPEND); + } + *tio->len_ptr -= bio_sectors - n_sectors; bio->bi_iter.bi_size = n_sectors << SECTOR_SHIFT; |