| Message ID | 20220823121859.163903-12-p.raghav@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v12,01/13] block: make bdev_nr_zones and disk_zone_no generic for npo2 zone size | expand |
On Tue, Aug 23 2022 at 8:18P -0400, Pankaj Raghav <p.raghav@samsung.com> wrote: > dm_zone_endio() updates the bi_sector of orig bio for zoned devices that > uses either native append or append emulation, and it is called before the > endio of the target. But target endio can still update the clone bio > after dm_zone_endio is called, thereby, the orig bio does not contain > the updated information anymore. > > Currently, this is not a problem as the targets that support zoned devices > such as dm-zoned, dm-linear, and dm-crypt do not have an endio function, > and even if they do (such as dm-flakey), they don't modify the > bio->bi_iter.bi_sector of the cloned bio that is used to update the > orig_bio's bi_sector in dm_zone_endio function. > > This is a prep patch for the new dm-po2zone target as it modifies > bi_sector in the endio callback. > > Call dm_zone_endio for zoned devices after calling the target's endio > function. > > Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Great patch header, explains the situation nicely. Reviewed-by: Mike Snitzer <snitzer@kernel.org>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 60549b65c799..58b392c51d04 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1122,10 +1122,6 @@ static void clone_endio(struct bio *bio) disable_write_zeroes(md); } - if (static_branch_unlikely(&zoned_enabled) && - unlikely(bdev_is_zoned(bio->bi_bdev))) - dm_zone_endio(io, bio); - if (endio) { int r = endio(ti, bio, &error); switch (r) { @@ -1154,6 +1150,10 @@ static void clone_endio(struct bio *bio) } } + if (static_branch_unlikely(&zoned_enabled) && + unlikely(bdev_is_zoned(bio->bi_bdev))) + dm_zone_endio(io, bio); + if (static_branch_unlikely(&swap_bios_enabled) && unlikely(swap_bios_limit(ti, bio))) up(&md->swap_bios_semaphore);
dm_zone_endio() updates the bi_sector of orig bio for zoned devices that uses either native append or append emulation, and it is called before the endio of the target. But target endio can still update the clone bio after dm_zone_endio is called, thereby, the orig bio does not contain the updated information anymore. Currently, this is not a problem as the targets that support zoned devices such as dm-zoned, dm-linear, and dm-crypt do not have an endio function, and even if they do (such as dm-flakey), they don't modify the bio->bi_iter.bi_sector of the cloned bio that is used to update the orig_bio's bi_sector in dm_zone_endio function. This is a prep patch for the new dm-po2zone target as it modifies bi_sector in the endio callback. Call dm_zone_endio for zoned devices after calling the target's endio function. Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> --- drivers/md/dm.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)