[PATCH 10/12] block: bypass the STABLE_WRITES flag for protection information

Christoph Hellwig
2024-06-13T08:49:16Z

Currently registering a checksum-enabled (aka PI) integrity profile sets
the QUEUE_FLAG_STABLE_WRITE flag, and unregistering it clears the flag.
This can incorrectly clear the flag when the driver requires stable
writes even without PI, e.g. in case of iSCSI or NVMe/TCP with data
digest enabled.

Fix this by looking at the csum_type directly in bdev_stable_writes and
not setting the queue flag. Also remove the blk_queue_stable_writes
helper as the only user in nvme wants to only look at the actual
QUEUE_FLAG_STABLE_WRITE flag as it inherits the integrity configuration
by other means.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
block/blk-integrity.c | 6 ------
drivers/nvme/host/multipath.c | 3 ++-
include/linux/blkdev.h | 12 ++++++++----
3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 1d2d371cd632d3..bec0d1df387ce9 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -379,9 +379,6 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template
bi->tag_size = template->tag_size;
bi->pi_offset = template->pi_offset;

- if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE)
- blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue);
-
#ifdef CONFIG_BLK_INLINE_ENCRYPTION
if (disk->queue->crypto_profile) {
pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n");
@@ -404,9 +401,6 @@ void blk_integrity_unregister(struct gendisk *disk)

if (!bi->tuple_size)
return;
-
- if (bi->csum_type != BLK_INTEGRITY_CSUM_NONE)
- blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue);
memset(bi, 0, sizeof(*bi));
}
EXPORT_SYMBOL(blk_integrity_unregister);
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index d8b6b4648eaff9..12c59db02539e5 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -875,7 +875,8 @@ void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid)
nvme_mpath_set_live(ns);
}

- if (blk_queue_stable_writes(ns->queue) && ns->head->disk)
+ if (test_bit(QUEUE_FLAG_STABLE_WRITES, &ns->queue->queue_flags) &&
+ ns->head->disk)
blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES,
ns->head->disk->queue);
#ifdef CONFIG_BLK_DEV_ZONED
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index bdd33388e1ced8..f9089750919c6b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -571,8 +571,6 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
#define blk_queue_noxmerges(q) \
test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
-#define blk_queue_stable_writes(q) \
- test_bit(QUEUE_FLAG_STABLE_WRITES, &(q)->queue_flags)
#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
#define blk_queue_zone_resetall(q) \
@@ -1300,8 +1298,14 @@ static inline bool bdev_synchronous(struct block_device *bdev)

static inline bool bdev_stable_writes(struct block_device *bdev)
{
- return test_bit(QUEUE_FLAG_STABLE_WRITES,
- &bdev_get_queue(bdev)->queue_flags);
+ struct request_queue *q = bdev_get_queue(bdev);
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+ /* BLK_INTEGRITY_CSUM_NONE is not available in blkdev.h */
+ if (q->integrity.csum_type != 0)
+ return true;
+#endif
+ return test_bit(QUEUE_FLAG_STABLE_WRITES, &q->queue_flags);
}

static inline bool bdev_write_cache(struct block_device *bdev)
--
2.43.0