block: move integrity information into queue_limits

Move the integrity information into the queue limits so that it can be
set atomically with other queue limits, and that the sysfs changes to
the read_verify and write_generate flags are properly synchronized.
This also allows to provide a more useful helper to stack the integrity
fields, although it still is separate from the main stacking function
as not all stackable devices want to inherit the integrity settings.
Even with that it greatly simplifies the code in md and dm.

Note that the integrity field is moved as-is into the queue limits.
While there are good arguments for removing the separate blk_integrity
structure, this would cause a lot of churn and might better be done at a
later time if desired.  However the integrity field in the queue_limits
structure is now unconditional so that various ifdefs can be avoided or
replaced with IS_ENABLED().  Given that tiny size of it that seems like
a worthwhile trade off.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 11 insertions, 16 deletions

diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c
index c1cc27541673..2a89f8eb4713 100644
--- a/drivers/md/dm-integrity.c
+++ b/drivers/md/dm-integrity.c
@@ -3475,6 +3475,17 @@ static void dm_integrity_io_hints(struct dm_target *ti, struct queue_limits *lim
 		limits->dma_alignment = limits->logical_block_size - 1;
 		limits->discard_granularity = ic->sectors_per_block << SECTOR_SHIFT;
 	}
+
+	if (!ic->internal_hash) {
+		struct blk_integrity *bi = &limits->integrity;
+
+		memset(bi, 0, sizeof(*bi));
+		bi->tuple_size = ic->tag_size;
+		bi->tag_size = bi->tuple_size;
+		bi->interval_exp =
+			ic->sb->log2_sectors_per_block + SECTOR_SHIFT;
+	}
+
 	limits->max_integrity_segments = USHRT_MAX;
 }
 
@@ -3631,19 +3642,6 @@ try_smaller_buffer:
 	return 0;
 }
 
-static void dm_integrity_set(struct dm_target *ti, struct dm_integrity_c *ic)
-{
-	struct gendisk *disk = dm_disk(dm_table_get_md(ti->table));
-	struct blk_integrity bi;
-
-	memset(&bi, 0, sizeof(bi));
-	bi.tuple_size = ic->tag_size;
-	bi.tag_size = bi.tuple_size;
-	bi.interval_exp = ic->sb->log2_sectors_per_block + SECTOR_SHIFT;
-
-	blk_integrity_register(disk, &bi);
-}
-
 static void dm_integrity_free_page_list(struct page_list *pl)
 {
 	unsigned int i;
@@ -4629,9 +4627,6 @@ try_smaller_buffer:
 		}
 	}
 
-	if (!ic->internal_hash)
-		dm_integrity_set(ti, ic);
-
 	ti->num_flush_bios = 1;
 	ti->flush_supported = true;
 	if (ic->discard)