--- /dev/null
+From e0910c8e4f87bb9f767e61a778b0d9271c4dc512 Mon Sep 17 00:00:00 2001
+From: Mike Snitzer <snitzer@redhat.com>
+Date: Thu, 24 Sep 2020 13:14:52 -0400
+Subject: dm raid: fix discard limits for raid1 and raid10
+
+From: Mike Snitzer <snitzer@redhat.com>
+
+commit e0910c8e4f87bb9f767e61a778b0d9271c4dc512 upstream.
+
+Block core warned that discard_granularity was 0 for dm-raid with
+personality of raid1. Reason is that raid_io_hints() was incorrectly
+special-casing raid1 rather than raid0.
+
+But since commit 29efc390b9462 ("md/md0: optimize raid0 discard
+handling") even raid0 properly handles large discards.
+
+Fix raid_io_hints() by removing discard limits settings for raid1.
+Also, fix limits for raid10 by properly stacking underlying limits as
+done in blk_stack_limits().
+
+Depends-on: 29efc390b9462 ("md/md0: optimize raid0 discard handling")
+Fixes: 61697a6abd24a ("dm: eliminate 'split_discard_bios' flag from DM target interface")
+Cc: stable@vger.kernel.org
+Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
+Reported-by: Mikulas Patocka <mpatocka@redhat.com>
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/md/dm-raid.c | 12 +++++++-----
+ 1 file changed, 7 insertions(+), 5 deletions(-)
+
+--- a/drivers/md/dm-raid.c
++++ b/drivers/md/dm-raid.c
+@@ -3730,12 +3730,14 @@ static void raid_io_hints(struct dm_targ
+ blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
+
+ /*
+- * RAID1 and RAID10 personalities require bio splitting,
+- * RAID0/4/5/6 don't and process large discard bios properly.
++ * RAID10 personality requires bio splitting,
++ * RAID0/1/4/5/6 don't and process large discard bios properly.
+ */
+- if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
+- limits->discard_granularity = chunk_size_bytes;
+- limits->max_discard_sectors = rs->md.chunk_sectors;
++ if (rs_is_raid10(rs)) {
++ limits->discard_granularity = max(chunk_size_bytes,
++ limits->discard_granularity);
++ limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
++ limits->max_discard_sectors);
+ }
+ }
+
--- /dev/null
+From 6ffeb1c3f8226244c08105bcdbeecc04bad6b89a Mon Sep 17 00:00:00 2001
+From: Mike Snitzer <snitzer@redhat.com>
+Date: Sat, 12 Dec 2020 11:55:37 -0500
+Subject: md: change mddev 'chunk_sectors' from int to unsigned
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Mike Snitzer <snitzer@redhat.com>
+
+commit 6ffeb1c3f8226244c08105bcdbeecc04bad6b89a upstream.
+
+Commit e2782f560c29 ("Revert "dm raid: remove unnecessary discard
+limits for raid10"") exposed compiler warnings introduced by commit
+e0910c8e4f87 ("dm raid: fix discard limits for raid1 and raid10"):
+
+In file included from ./include/linux/kernel.h:14,
+ from ./include/asm-generic/bug.h:20,
+ from ./arch/x86/include/asm/bug.h:93,
+ from ./include/linux/bug.h:5,
+ from ./include/linux/mmdebug.h:5,
+ from ./include/linux/gfp.h:5,
+ from ./include/linux/slab.h:15,
+ from drivers/md/dm-raid.c:8:
+drivers/md/dm-raid.c: In function ‘raid_io_hints’:
+./include/linux/minmax.h:18:28: warning: comparison of distinct pointer types lacks a cast
+ (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
+ ^~
+./include/linux/minmax.h:32:4: note: in expansion of macro ‘__typecheck’
+ (__typecheck(x, y) && __no_side_effects(x, y))
+ ^~~~~~~~~~~
+./include/linux/minmax.h:42:24: note: in expansion of macro ‘__safe_cmp’
+ __builtin_choose_expr(__safe_cmp(x, y), \
+ ^~~~~~~~~~
+./include/linux/minmax.h:51:19: note: in expansion of macro ‘__careful_cmp’
+ #define min(x, y) __careful_cmp(x, y, <)
+ ^~~~~~~~~~~~~
+./include/linux/minmax.h:84:39: note: in expansion of macro ‘min’
+ __x == 0 ? __y : ((__y == 0) ? __x : min(__x, __y)); })
+ ^~~
+drivers/md/dm-raid.c:3739:33: note: in expansion of macro ‘min_not_zero’
+ limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
+ ^~~~~~~~~~~~
+
+Fix this by changing the chunk_sectors member of 'struct mddev' from
+int to 'unsigned int' to match the type used for the 'chunk_sectors'
+member of 'struct queue_limits'. Various MD code still uses 'int' but
+none of it appears to ever make use of signed int; and storing
+positive signed int in unsigned is perfectly safe.
+
+Reported-by: Song Liu <songliubraving@fb.com>
+Fixes: e2782f560c29 ("Revert "dm raid: remove unnecessary discard limits for raid10"")
+Fixes: e0910c8e4f87 ("dm raid: fix discard limits for raid1 and raid10")
+Cc: stable@vger,kernel.org # e0910c8e4f87 was marked for stable@
+Signed-off-by: Mike Snitzer <snitzer@redhat.com>
+Reviewed-by: Song Liu <song@kernel.org>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/md/md.h | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/drivers/md/md.h
++++ b/drivers/md/md.h
+@@ -311,7 +311,7 @@ struct mddev {
+ int external; /* metadata is
+ * managed externally */
+ char metadata_type[17]; /* externally set*/
+- int chunk_sectors;
++ unsigned int chunk_sectors;
+ time64_t ctime, utime;
+ int level, layout;
+ char clevel[16];
+@@ -339,7 +339,7 @@ struct mddev {
+ */
+ sector_t reshape_position;
+ int delta_disks, new_level, new_layout;
+- int new_chunk_sectors;
++ unsigned int new_chunk_sectors;
+ int reshape_backwards;
+
+ struct md_thread *thread; /* management thread */
projects / thirdparty / kernel / stable-queue.git / commitdiff
