support file system generated / verified integrity information v4

support file system generated / verified integrity information v4

[Christoph Hellwig]

Hi all,

this series adds support to generate and verify integrity information
(aka T10 PI) in the file system, instead of the automatic below the
covers support that is currently used.

There two reasons for this:

  a) to increase the protection enveloped.  Right now this is just a
     minor step from the bottom of the block layer to the file system,
     but it is required to support io_uring integrity data passthrough in
     the file system similar to the currently existing support for block
     devices, which will follow next.  It also allows the file system to
     directly see the integrity error and act upon in, e.g. when using
     RAID either integrated (as in btrfs) or by supporting reading
     redundant copies through the block layer.
  b) to make the PI processing more efficient.  This is primarily a
     concern for reads, where the block layer auto PI has to schedule a
     work item for each bio, and the file system them has to do it again
     for bounce buffering.  Additionally the current iomap post-I/O
     workqueue handling is a lot more efficient by supporting merging and
     avoiding workqueue scheduling storms.

The implementation is based on refactoring the existing block layer PI
code to be reusable for this use case, and then adding relatively small
wrappers for the file system use case.  These are then used in iomap
to implement the semantics, and wired up in XFS with a small amount of
glue code.

Compared to the baseline (iomap-bounce branch), this does not change
performance for writes, but increases read performance up to 15% for 4k
I/O, with the benefit decreasing with larger I/O sizes as even the
baseline maxes out the device quickly on my older enterprise SSD.

Anuj Gupta also measured a large decrease in QD1 latency on an Intel
Optane device for small I/O sizes, but also an increase for very large
ones.

Note that the upcoming XFS fsverity support also depends on some
infrastructure in this series.

Git tree:

    git://git.infradead.org/users/hch/misc.git iomap-pi

Gitweb:

    https://git.infradead.org/?p=users/hch/misc.git;a=shortlog;h=refs/heads/iomap-pi

Changes since v3:
 - fix the mess than the ntfs3 tree cause in 6.19
 - rebase to 7.0-rc1

Changes since v2:
 - rebased to current linus tree
 - use folio->mapping instead of file->f_mapping to support the upcoming
   fsverity use case
 - rename and slightly refactor the xfs iomap read ops to better addres
   that this will be used by fsverity as well.

Changes since v1:
 - document usage of BI_ACT_*
 - return the action from fs_bio_integrity_alloc and use it in
   fs_bio_integrity_generation to be safe from misuse
 - use the newly added BIO_MAX_SIZE
 - rename bio_read_ops to xfs_bio_read_ops
 - fix commit message and comment typos

Diffstat:
 block/Makefile                |    2 
 block/bio-integrity-auto.c    |   80 +++---------------------
 block/bio-integrity-fs.c      |   81 +++++++++++++++++++++++++
 block/bio-integrity.c         |   64 +++++++++++++++++++
 block/bio.c                   |   17 +++--
 block/blk-mq.c                |    6 +
 block/blk-settings.c          |   13 ----
 block/blk.h                   |    6 +
 block/t10-pi.c                |   12 +--
 drivers/nvdimm/btt.c          |    6 +
 fs/fuse/file.c                |    5 -
 fs/iomap/bio.c                |  135 ++++++++++++++++++++++++++++--------------
 fs/iomap/buffered-io.c        |    8 +-
 fs/iomap/direct-io.c          |   15 ++++
 fs/iomap/internal.h           |   14 ++++
 fs/iomap/ioend.c              |   28 +++++++-
 fs/ntfs3/inode.c              |   57 +----------------
 fs/xfs/xfs_aops.c             |   47 +++++++++++++-
 fs/xfs/xfs_iomap.c            |    9 +-
 include/linux/bio-integrity.h |   12 ++-
 include/linux/bio.h           |    2 
 include/linux/blk-integrity.h |   28 +++++++-
 include/linux/blkdev.h        |   34 ++++++++--
 include/linux/iomap.h         |   20 +++++-
 24 files changed, 469 insertions(+), 232 deletions(-)

[PATCH 01/16] block: factor out a bio_integrity_action helper

[Christoph Hellwig]

Split the logic to see if a bio needs integrity metadata from
bio_integrity_prep into a reusable helper than can be called from
file system code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/bio-integrity-auto.c    | 64 +++++------------------------------
 block/bio-integrity.c         | 48 ++++++++++++++++++++++++++
 block/blk-mq.c                |  6 ++--
 drivers/nvdimm/btt.c          |  6 ++--
 include/linux/bio-integrity.h |  5 ++-
 include/linux/blk-integrity.h | 23 +++++++++++++
 6 files changed, 89 insertions(+), 63 deletions(-)

diff --git a/block/bio-integrity-auto.c b/block/bio-integrity-auto.c
index 44dcdf7520c5..e16f669dbf1e 100644
--- a/block/bio-integrity-auto.c
+++ b/block/bio-integrity-auto.c
@@ -50,11 +50,6 @@ static bool bip_should_check(struct bio_integrity_payload *bip)
 	return bip->bip_flags & BIP_CHECK_FLAGS;
 }
 
-static bool bi_offload_capable(struct blk_integrity *bi)
-{
-	return bi->metadata_size == bi->pi_tuple_size;
-}
-
 /**
  * __bio_integrity_endio - Integrity I/O completion function
  * @bio:	Protected bio
@@ -84,69 +79,27 @@ bool __bio_integrity_endio(struct bio *bio)
 /**
  * bio_integrity_prep - Prepare bio for integrity I/O
  * @bio:	bio to prepare
+ * @action:	preparation action needed (BI_ACT_*)
+ *
+ * Allocate the integrity payload.  For writes, generate the integrity metadata
+ * and for reads, setup the completion handler to verify the metadata.
  *
- * Checks if the bio already has an integrity payload attached.  If it does, the
- * payload has been generated by another kernel subsystem, and we just pass it
- * through.
- * Otherwise allocates integrity payload and for writes the integrity metadata
- * will be generated.  For reads, the completion handler will verify the
- * metadata.
+ * This is used for bios that do not have user integrity payloads attached.
  */
-bool bio_integrity_prep(struct bio *bio)
+void bio_integrity_prep(struct bio *bio, unsigned int action)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_data *bid;
-	bool set_flags = true;
-	gfp_t gfp = GFP_NOIO;
-
-	if (!bi)
-		return true;
-
-	if (!bio_sectors(bio))
-		return true;
-
-	/* Already protected? */
-	if (bio_integrity(bio))
-		return true;
-
-	switch (bio_op(bio)) {
-	case REQ_OP_READ:
-		if (bi->flags & BLK_INTEGRITY_NOVERIFY) {
-			if (bi_offload_capable(bi))
-				return true;
-			set_flags = false;
-		}
-		break;
-	case REQ_OP_WRITE:
-		/*
-		 * Zero the memory allocated to not leak uninitialized kernel
-		 * memory to disk for non-integrity metadata where nothing else
-		 * initializes the memory.
-		 */
-		if (bi->flags & BLK_INTEGRITY_NOGENERATE) {
-			if (bi_offload_capable(bi))
-				return true;
-			set_flags = false;
-			gfp |= __GFP_ZERO;
-		} else if (bi->metadata_size > bi->pi_tuple_size)
-			gfp |= __GFP_ZERO;
-		break;
-	default:
-		return true;
-	}
-
-	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
-		return true;
 
 	bid = mempool_alloc(&bid_pool, GFP_NOIO);
 	bio_integrity_init(bio, &bid->bip, &bid->bvec, 1);
 	bid->bio = bio;
 	bid->bip.bip_flags |= BIP_BLOCK_INTEGRITY;
-	bio_integrity_alloc_buf(bio, gfp & __GFP_ZERO);
+	bio_integrity_alloc_buf(bio, action & BI_ACT_ZERO);
 
 	bip_set_seed(&bid->bip, bio->bi_iter.bi_sector);
 
-	if (set_flags) {
+	if (action & BI_ACT_CHECK) {
 		if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
 			bid->bip.bip_flags |= BIP_IP_CHECKSUM;
 		if (bi->csum_type)
@@ -160,7 +113,6 @@ bool bio_integrity_prep(struct bio *bio)
 		blk_integrity_generate(bio);
 	else
 		bid->saved_bio_iter = bio->bi_iter;
-	return true;
 }
 EXPORT_SYMBOL(bio_integrity_prep);
 
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 20f5d301d32d..0955be90038b 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/blk-integrity.h>
+#include <linux/t10-pi.h>
 #include "blk.h"
 
 struct bio_integrity_alloc {
@@ -16,6 +17,53 @@ struct bio_integrity_alloc {
 
 static mempool_t integrity_buf_pool;
 
+static bool bi_offload_capable(struct blk_integrity *bi)
+{
+	return bi->metadata_size == bi->pi_tuple_size;
+}
+
+unsigned int __bio_integrity_action(struct bio *bio)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+
+	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
+		return 0;
+
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
+		if (bi->flags & BLK_INTEGRITY_NOVERIFY) {
+			if (bi_offload_capable(bi))
+				return 0;
+			return BI_ACT_BUFFER;
+		}
+		return BI_ACT_BUFFER | BI_ACT_CHECK;
+	case REQ_OP_WRITE:
+		/*
+		 * Flush masquerading as write?
+		 */
+		if (!bio_sectors(bio))
+			return 0;
+
+		/*
+		 * Zero the memory allocated to not leak uninitialized kernel
+		 * memory to disk for non-integrity metadata where nothing else
+		 * initializes the memory.
+		 */
+		if (bi->flags & BLK_INTEGRITY_NOGENERATE) {
+			if (bi_offload_capable(bi))
+				return 0;
+			return BI_ACT_BUFFER | BI_ACT_ZERO;
+		}
+
+		if (bi->metadata_size > bi->pi_tuple_size)
+			return BI_ACT_BUFFER | BI_ACT_CHECK | BI_ACT_ZERO;
+		return BI_ACT_BUFFER | BI_ACT_CHECK;
+	default:
+		return 0;
+	}
+}
+EXPORT_SYMBOL_GPL(__bio_integrity_action);
+
 void bio_integrity_alloc_buf(struct bio *bio, bool zero_buffer)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9af8c3dec3f6..0b311a797178 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3143,6 +3143,7 @@ void blk_mq_submit_bio(struct bio *bio)
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	struct blk_plug *plug = current->plug;
 	const int is_sync = op_is_sync(bio->bi_opf);
+	unsigned int integrity_action;
 	struct blk_mq_hw_ctx *hctx;
 	unsigned int nr_segs;
 	struct request *rq;
@@ -3195,8 +3196,9 @@ void blk_mq_submit_bio(struct bio *bio)
 	if (!bio)
 		goto queue_exit;
 
-	if (!bio_integrity_prep(bio))
-		goto queue_exit;
+	integrity_action = bio_integrity_action(bio);
+	if (integrity_action)
+		bio_integrity_prep(bio, integrity_action);
 
 	blk_mq_bio_issue_init(q, bio);
 	if (blk_mq_attempt_bio_merge(q, bio, nr_segs))
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index b6bef092f8b8..fdcb080a4314 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1435,14 +1435,16 @@ static void btt_submit_bio(struct bio *bio)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct btt *btt = bio->bi_bdev->bd_disk->private_data;
+	unsigned int integrity_action;
 	struct bvec_iter iter;
 	unsigned long start;
 	struct bio_vec bvec;
 	int err = 0;
 	bool do_acct;
 
-	if (!bio_integrity_prep(bio))
-		return;
+	integrity_action = bio_integrity_action(bio);
+	if (integrity_action)
+		bio_integrity_prep(bio, integrity_action);
 
 	do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
 	if (do_acct)
diff --git a/include/linux/bio-integrity.h b/include/linux/bio-integrity.h
index 21e4652dcfd2..276cbbdd2c9d 100644
--- a/include/linux/bio-integrity.h
+++ b/include/linux/bio-integrity.h
@@ -78,7 +78,7 @@ int bio_integrity_add_page(struct bio *bio, struct page *page, unsigned int len,
 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter);
 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta);
 void bio_integrity_unmap_user(struct bio *bio);
-bool bio_integrity_prep(struct bio *bio);
+void bio_integrity_prep(struct bio *bio, unsigned int action);
 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done);
 void bio_integrity_trim(struct bio *bio);
 int bio_integrity_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp_mask);
@@ -104,9 +104,8 @@ static inline void bio_integrity_unmap_user(struct bio *bio)
 {
 }
 
-static inline bool bio_integrity_prep(struct bio *bio)
+static inline void bio_integrity_prep(struct bio *bio, unsigned int action)
 {
-	return true;
 }
 
 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index c15b1ac62765..fd3f3c8c0fcd 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h
@@ -180,4 +180,27 @@ static inline struct bio_vec rq_integrity_vec(struct request *rq)
 }
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
+enum bio_integrity_action {
+	BI_ACT_BUFFER		= (1u << 0),	/* allocate buffer */
+	BI_ACT_CHECK		= (1u << 1),	/* generate / verify PI */
+	BI_ACT_ZERO		= (1u << 2),	/* zero buffer */
+};
+
+/**
+ * bio_integrity_action - return the integrity action needed for a bio
+ * @bio:	bio to operate on
+ *
+ * Returns the mask of integrity actions (BI_ACT_*) that need to be performed
+ * for @bio.
+ */
+unsigned int __bio_integrity_action(struct bio *bio);
+static inline unsigned int bio_integrity_action(struct bio *bio)
+{
+	if (!blk_get_integrity(bio->bi_bdev->bd_disk))
+		return 0;
+	if (bio_integrity(bio))
+		return 0;
+	return __bio_integrity_action(bio);
+}
+
 #endif /* _LINUX_BLK_INTEGRITY_H */
-- 
2.47.3

[PATCH 02/16] block: factor out a bio_integrity_setup_default helper

[Christoph Hellwig]

Add a helper to set the seed and check flag based on useful defaults
from the profile.

Note that this includes a small behavior change, as we now only set the
seed if any action is set, which is fine as nothing will look at it
otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/bio-integrity-auto.c    | 14 ++------------
 block/bio-integrity.c         | 16 ++++++++++++++++
 include/linux/bio-integrity.h |  1 +
 3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/block/bio-integrity-auto.c b/block/bio-integrity-auto.c
index e16f669dbf1e..b64c71a7fc82 100644
--- a/block/bio-integrity-auto.c
+++ b/block/bio-integrity-auto.c
@@ -88,7 +88,6 @@ bool __bio_integrity_endio(struct bio *bio)
  */
 void bio_integrity_prep(struct bio *bio, unsigned int action)
 {
-	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_data *bid;
 
 	bid = mempool_alloc(&bid_pool, GFP_NOIO);
@@ -96,17 +95,8 @@ void bio_integrity_prep(struct bio *bio, unsigned int action)
 	bid->bio = bio;
 	bid->bip.bip_flags |= BIP_BLOCK_INTEGRITY;
 	bio_integrity_alloc_buf(bio, action & BI_ACT_ZERO);
-
-	bip_set_seed(&bid->bip, bio->bi_iter.bi_sector);
-
-	if (action & BI_ACT_CHECK) {
-		if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
-			bid->bip.bip_flags |= BIP_IP_CHECKSUM;
-		if (bi->csum_type)
-			bid->bip.bip_flags |= BIP_CHECK_GUARD;
-		if (bi->flags & BLK_INTEGRITY_REF_TAG)
-			bid->bip.bip_flags |= BIP_CHECK_REFTAG;
-	}
+	if (action & BI_ACT_CHECK)
+		bio_integrity_setup_default(bio);
 
 	/* Auto-generate integrity metadata if this is a write */
 	if (bio_data_dir(bio) == WRITE && bip_should_check(&bid->bip))
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index 0955be90038b..e79eaf047794 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -101,6 +101,22 @@ void bio_integrity_free_buf(struct bio_integrity_payload *bip)
 		kfree(bvec_virt(bv));
 }
 
+void bio_integrity_setup_default(struct bio *bio)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+
+	bip_set_seed(bip, bio->bi_iter.bi_sector);
+
+	if (bi->csum_type) {
+		bip->bip_flags |= BIP_CHECK_GUARD;
+		if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
+			bip->bip_flags |= BIP_IP_CHECKSUM;
+	}
+	if (bi->flags & BLK_INTEGRITY_REF_TAG)
+		bip->bip_flags |= BIP_CHECK_REFTAG;
+}
+
 /**
  * bio_integrity_free - Free bio integrity payload
  * @bio:	bio containing bip to be freed
diff --git a/include/linux/bio-integrity.h b/include/linux/bio-integrity.h
index 276cbbdd2c9d..232b86b9bbcb 100644
--- a/include/linux/bio-integrity.h
+++ b/include/linux/bio-integrity.h
@@ -143,5 +143,6 @@ static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
 
 void bio_integrity_alloc_buf(struct bio *bio, bool zero_buffer);
 void bio_integrity_free_buf(struct bio_integrity_payload *bip);
+void bio_integrity_setup_default(struct bio *bio);
 
 #endif /* _LINUX_BIO_INTEGRITY_H */
-- 
2.47.3

[PATCH 03/16] block: add a bdev_has_integrity_csum helper

[Christoph Hellwig]

Factor out a helper to see if the block device has an integrity checksum
from bdev_stable_writes so that it can be reused for other checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 include/linux/blkdev.h | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d463b9b5a0a5..dec0acaed6e6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1477,14 +1477,18 @@ static inline bool bdev_synchronous(struct block_device *bdev)
 	return bdev->bd_disk->queue->limits.features & BLK_FEAT_SYNCHRONOUS;
 }
 
-static inline bool bdev_stable_writes(struct block_device *bdev)
+static inline bool bdev_has_integrity_csum(struct block_device *bdev)
 {
-	struct request_queue *q = bdev_get_queue(bdev);
+	struct queue_limits *lim = bdev_limits(bdev);
 
-	if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
-	    q->limits.integrity.csum_type != BLK_INTEGRITY_CSUM_NONE)
-		return true;
-	return q->limits.features & BLK_FEAT_STABLE_WRITES;
+	return IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) &&
+		lim->integrity.csum_type != BLK_INTEGRITY_CSUM_NONE;
+}
+
+static inline bool bdev_stable_writes(struct block_device *bdev)
+{
+	return bdev_has_integrity_csum(bdev) ||
+		(bdev_limits(bdev)->features & BLK_FEAT_STABLE_WRITES);
 }
 
 static inline bool blk_queue_write_cache(struct request_queue *q)
-- 
2.47.3

[PATCH 04/16] block: prepare generation / verification helpers for fs usage

[Christoph Hellwig]

Return the status from verify instead of directly stashing it in the bio,
and rename the helpers to use the usual bio_ prefix for things operating
on a bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/bio-integrity-auto.c |  4 ++--
 block/blk.h                |  6 ++++--
 block/t10-pi.c             | 12 ++++++------
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/block/bio-integrity-auto.c b/block/bio-integrity-auto.c
index b64c71a7fc82..ebd17f47e0f9 100644
--- a/block/bio-integrity-auto.c
+++ b/block/bio-integrity-auto.c
@@ -39,7 +39,7 @@ static void bio_integrity_verify_fn(struct work_struct *work)
 		container_of(work, struct bio_integrity_data, work);
 	struct bio *bio = bid->bio;
 
-	blk_integrity_verify_iter(bio, &bid->saved_bio_iter);
+	bio->bi_status = bio_integrity_verify(bio, &bid->saved_bio_iter);
 	bio_integrity_finish(bid);
 	bio_endio(bio);
 }
@@ -100,7 +100,7 @@ void bio_integrity_prep(struct bio *bio, unsigned int action)
 
 	/* Auto-generate integrity metadata if this is a write */
 	if (bio_data_dir(bio) == WRITE && bip_should_check(&bid->bip))
-		blk_integrity_generate(bio);
+		bio_integrity_generate(bio);
 	else
 		bid->saved_bio_iter = bio->bi_iter;
 }
diff --git a/block/blk.h b/block/blk.h
index f6053e9dd2aa..c5b2115b9ea4 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -699,8 +699,10 @@ int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
 	      const struct blk_holder_ops *hops, struct file *bdev_file);
 int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
 
-void blk_integrity_generate(struct bio *bio);
-void blk_integrity_verify_iter(struct bio *bio, struct bvec_iter *saved_iter);
+void bio_integrity_generate(struct bio *bio);
+blk_status_t bio_integrity_verify(struct bio *bio,
+		struct bvec_iter *saved_iter);
+
 void blk_integrity_prepare(struct request *rq);
 void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
 
diff --git a/block/t10-pi.c b/block/t10-pi.c
index 0c4ed9702146..d27be6041fd3 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -372,7 +372,7 @@ static void ext_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
 	}
 }
 
-void blk_integrity_generate(struct bio *bio)
+void bio_integrity_generate(struct bio *bio)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);
@@ -404,7 +404,7 @@ void blk_integrity_generate(struct bio *bio)
 	}
 }
 
-void blk_integrity_verify_iter(struct bio *bio, struct bvec_iter *saved_iter)
+blk_status_t bio_integrity_verify(struct bio *bio, struct bvec_iter *saved_iter)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);
@@ -439,11 +439,11 @@ void blk_integrity_verify_iter(struct bio *bio, struct bvec_iter *saved_iter)
 		}
 		kunmap_local(kaddr);
 
-		if (ret) {
-			bio->bi_status = ret;
-			return;
-		}
+		if (ret)
+			return ret;
 	}
+
+	return BLK_STS_OK;
 }
 
 void blk_integrity_prepare(struct request *rq)
-- 
2.47.3

[PATCH 05/16] block: make max_integrity_io_size public

[Christoph Hellwig]

File systems that generate integrity will need this, so move it out
of the block private or blk-mq specific headers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/blk-settings.c          | 13 -------------
 include/linux/blk-integrity.h |  5 -----
 include/linux/blkdev.h        | 18 ++++++++++++++++++
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index a9e65dc090da..dabfab97fbab 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -123,19 +123,6 @@ static int blk_validate_zoned_limits(struct queue_limits *lim)
 	return 0;
 }
 
-/*
- * Maximum size of I/O that needs a block layer integrity buffer.  Limited
- * by the number of intervals for which we can fit the integrity buffer into
- * the buffer size.  Because the buffer is a single segment it is also limited
- * by the maximum segment size.
- */
-static inline unsigned int max_integrity_io_size(struct queue_limits *lim)
-{
-	return min_t(unsigned int, lim->max_segment_size,
-		(BLK_INTEGRITY_MAX_SIZE / lim->integrity.metadata_size) <<
-			lim->integrity.interval_exp);
-}
-
 static int blk_validate_integrity_limits(struct queue_limits *lim)
 {
 	struct blk_integrity *bi = &lim->integrity;
diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index fd3f3c8c0fcd..ea6d7d322ae3 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h
@@ -8,11 +8,6 @@
 
 struct request;
 
-/*
- * Maximum contiguous integrity buffer allocation.
- */
-#define BLK_INTEGRITY_MAX_SIZE		SZ_2M
-
 enum blk_integrity_flags {
 	BLK_INTEGRITY_NOVERIFY		= 1 << 0,
 	BLK_INTEGRITY_NOGENERATE	= 1 << 1,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index dec0acaed6e6..11857ae13d10 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1881,6 +1881,24 @@ static inline int bio_split_rw_at(struct bio *bio,
 	return bio_split_io_at(bio, lim, segs, max_bytes, lim->dma_alignment);
 }
 
+/*
+ * Maximum contiguous integrity buffer allocation.
+ */
+#define BLK_INTEGRITY_MAX_SIZE		SZ_2M
+
+/*
+ * Maximum size of I/O that needs a block layer integrity buffer.  Limited
+ * by the number of intervals for which we can fit the integrity buffer into
+ * the buffer size.  Because the buffer is a single segment it is also limited
+ * by the maximum segment size.
+ */
+static inline unsigned int max_integrity_io_size(struct queue_limits *lim)
+{
+	return min_t(unsigned int, lim->max_segment_size,
+		(BLK_INTEGRITY_MAX_SIZE / lim->integrity.metadata_size) <<
+			lim->integrity.interval_exp);
+}
+
 #define DEFINE_IO_COMP_BATCH(name)	struct io_comp_batch name = { }
 
 #endif /* _LINUX_BLKDEV_H */
-- 
2.47.3

[PATCH 06/16] block: add fs_bio_integrity helpers

[Christoph Hellwig]

Add a set of helpers for file system initiated integrity information.
These include mempool backed allocations and verifying based on a passed
in sector and size which is often available from file system completion
routines.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/Makefile                |  2 +-
 block/bio-integrity-fs.c      | 81 +++++++++++++++++++++++++++++++++++
 include/linux/bio-integrity.h |  6 +++
 3 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 block/bio-integrity-fs.c

diff --git a/block/Makefile b/block/Makefile
index c65f4da93702..7dce2e44276c 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -26,7 +26,7 @@ bfq-y				:= bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
 obj-$(CONFIG_IOSCHED_BFQ)	+= bfq.o
 
 obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o \
-				   bio-integrity-auto.o
+				   bio-integrity-auto.o bio-integrity-fs.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
diff --git a/block/bio-integrity-fs.c b/block/bio-integrity-fs.c
new file mode 100644
index 000000000000..acb1e5f270d2
--- /dev/null
+++ b/block/bio-integrity-fs.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Christoph Hellwig.
+ */
+#include <linux/blk-integrity.h>
+#include <linux/bio-integrity.h>
+#include "blk.h"
+
+struct fs_bio_integrity_buf {
+	struct bio_integrity_payload	bip;
+	struct bio_vec			bvec;
+};
+
+static struct kmem_cache *fs_bio_integrity_cache;
+static mempool_t fs_bio_integrity_pool;
+
+unsigned int fs_bio_integrity_alloc(struct bio *bio)
+{
+	struct fs_bio_integrity_buf *iib;
+	unsigned int action;
+
+	action = bio_integrity_action(bio);
+	if (!action)
+		return 0;
+
+	iib = mempool_alloc(&fs_bio_integrity_pool, GFP_NOIO);
+	bio_integrity_init(bio, &iib->bip, &iib->bvec, 1);
+
+	bio_integrity_alloc_buf(bio, action & BI_ACT_ZERO);
+	if (action & BI_ACT_CHECK)
+		bio_integrity_setup_default(bio);
+	return action;
+}
+
+void fs_bio_integrity_free(struct bio *bio)
+{
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+
+	bio_integrity_free_buf(bip);
+	mempool_free(container_of(bip, struct fs_bio_integrity_buf, bip),
+			&fs_bio_integrity_pool);
+
+	bio->bi_integrity = NULL;
+	bio->bi_opf &= ~REQ_INTEGRITY;
+}
+
+void fs_bio_integrity_generate(struct bio *bio)
+{
+	if (fs_bio_integrity_alloc(bio))
+		bio_integrity_generate(bio);
+}
+EXPORT_SYMBOL_GPL(fs_bio_integrity_generate);
+
+int fs_bio_integrity_verify(struct bio *bio, sector_t sector, unsigned int size)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+
+	/*
+	 * Reinitialize bip->bip_iter.
+	 *
+	 * This is for use in the submitter after the driver is done with the
+	 * bio.  Requires the submitter to remember the sector and the size.
+	 */
+	memset(&bip->bip_iter, 0, sizeof(bip->bip_iter));
+	bip->bip_iter.bi_sector = sector;
+	bip->bip_iter.bi_size = bio_integrity_bytes(bi, size >> SECTOR_SHIFT);
+	return blk_status_to_errno(bio_integrity_verify(bio, &bip->bip_iter));
+}
+
+static int __init fs_bio_integrity_init(void)
+{
+	fs_bio_integrity_cache = kmem_cache_create("fs_bio_integrity",
+			sizeof(struct fs_bio_integrity_buf), 0,
+			SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+	if (mempool_init_slab_pool(&fs_bio_integrity_pool, BIO_POOL_SIZE,
+			fs_bio_integrity_cache))
+		panic("fs_bio_integrity: can't create pool\n");
+	return 0;
+}
+fs_initcall(fs_bio_integrity_init);
diff --git a/include/linux/bio-integrity.h b/include/linux/bio-integrity.h
index 232b86b9bbcb..af5178434ec6 100644
--- a/include/linux/bio-integrity.h
+++ b/include/linux/bio-integrity.h
@@ -145,4 +145,10 @@ void bio_integrity_alloc_buf(struct bio *bio, bool zero_buffer);
 void bio_integrity_free_buf(struct bio_integrity_payload *bip);
 void bio_integrity_setup_default(struct bio *bio);
 
+unsigned int fs_bio_integrity_alloc(struct bio *bio);
+void fs_bio_integrity_free(struct bio *bio);
+void fs_bio_integrity_generate(struct bio *bio);
+int fs_bio_integrity_verify(struct bio *bio, sector_t sector,
+		unsigned int size);
+
 #endif /* _LINUX_BIO_INTEGRITY_H */
-- 
2.47.3

[PATCH 07/16] block: pass a maxlen argument to bio_iov_iter_bounce

[Christoph Hellwig]

Allow the file system to limit the size processed in a single
bounce operation.  This is needed when generating integrity data
so that the size of a single integrity segment can't overflow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 block/bio.c          | 17 ++++++++++-------
 fs/iomap/direct-io.c |  2 +-
 include/linux/bio.h  |  2 +-
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index d80d5d26804e..784d2a66d3ae 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1327,9 +1327,10 @@ static void bio_free_folios(struct bio *bio)
 	}
 }
 
-static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter)
+static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter,
+		size_t maxlen)
 {
-	size_t total_len = iov_iter_count(iter);
+	size_t total_len = min(maxlen, iov_iter_count(iter));
 
 	if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
 		return -EINVAL;
@@ -1367,9 +1368,10 @@ static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter)
 	return 0;
 }
 
-static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter)
+static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter,
+		size_t maxlen)
 {
-	size_t len = min(iov_iter_count(iter), SZ_1M);
+	size_t len = min3(iov_iter_count(iter), maxlen, SZ_1M);
 	struct folio *folio;
 
 	folio = folio_alloc_greedy(GFP_KERNEL, &len);
@@ -1408,6 +1410,7 @@ static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter)
  * bio_iov_iter_bounce - bounce buffer data from an iter into a bio
  * @bio:	bio to send
  * @iter:	iter to read from / write into
+ * @maxlen:	maximum size to bounce
  *
  * Helper for direct I/O implementations that need to bounce buffer because
  * we need to checksum the data or perform other operations that require
@@ -1415,11 +1418,11 @@ static int bio_iov_iter_bounce_read(struct bio *bio, struct iov_iter *iter)
  * copies the data into it.  Needs to be paired with bio_iov_iter_unbounce()
  * called on completion.
  */
-int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter)
+int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter, size_t maxlen)
 {
 	if (op_is_write(bio_op(bio)))
-		return bio_iov_iter_bounce_write(bio, iter);
-	return bio_iov_iter_bounce_read(bio, iter);
+		return bio_iov_iter_bounce_write(bio, iter, maxlen);
+	return bio_iov_iter_bounce_read(bio, iter, maxlen);
 }
 
 static void bvec_unpin(struct bio_vec *bv, bool mark_dirty)
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 95254aa1b654..21d4fad2eeb8 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -338,7 +338,7 @@ static ssize_t iomap_dio_bio_iter_one(struct iomap_iter *iter,
 	bio->bi_end_io = iomap_dio_bio_end_io;
 
 	if (dio->flags & IOMAP_DIO_BOUNCE)
-		ret = bio_iov_iter_bounce(bio, dio->submit.iter);
+		ret = bio_iov_iter_bounce(bio, dio->submit.iter, BIO_MAX_SIZE);
 	else
 		ret = bio_iov_iter_get_pages(bio, dio->submit.iter,
 					     alignment - 1);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 36a3f2275ecd..9693a0d6fefe 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -474,7 +474,7 @@ void __bio_release_pages(struct bio *bio, bool mark_dirty);
 extern void bio_set_pages_dirty(struct bio *bio);
 extern void bio_check_pages_dirty(struct bio *bio);
 
-int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter);
+int bio_iov_iter_bounce(struct bio *bio, struct iov_iter *iter, size_t maxlen);
 void bio_iov_iter_unbounce(struct bio *bio, bool is_error, bool mark_dirty);
 
 extern void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
-- 
2.47.3

[PATCH 08/16] iomap: refactor iomap_bio_read_folio_range

[Christoph Hellwig]

Split out the logic to allocate a new bio and only keep the fast path
that adds more data to an existing bio in iomap_bio_read_folio_range.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c | 69 +++++++++++++++++++++++++++-----------------------
 1 file changed, 37 insertions(+), 32 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index fc045f2e4c45..578b1202e037 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -26,45 +26,50 @@ static void iomap_bio_submit_read(struct iomap_read_folio_ctx *ctx)
 		submit_bio(bio);
 }
 
-static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
+static void iomap_read_alloc_bio(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx, size_t plen)
 {
-	struct folio *folio = ctx->cur_folio;
 	const struct iomap *iomap = &iter->iomap;
-	loff_t pos = iter->pos;
-	size_t poff = offset_in_folio(folio, pos);
-	loff_t length = iomap_length(iter);
-	sector_t sector;
+	unsigned int nr_vecs = DIV_ROUND_UP(iomap_length(iter), PAGE_SIZE);
+	struct folio *folio = ctx->cur_folio;
+	gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
+	gfp_t orig_gfp = gfp;
 	struct bio *bio = ctx->read_ctx;
 
-	sector = iomap_sector(iomap, pos);
-	if (!bio || bio_end_sector(bio) != sector ||
-	    !bio_add_folio(bio, folio, plen, poff)) {
-		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
-		gfp_t orig_gfp = gfp;
-		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
+	if (bio)
+		submit_bio(bio);
+
+	/* Same as readahead_gfp_mask: */
+	if (ctx->rac)
+		gfp |= __GFP_NORETRY | __GFP_NOWARN;
 
-		if (bio)
-			submit_bio(bio);
+	/*
+	 * If the bio_alloc fails, try it again for a single page to avoid
+	 * having to deal with partial page reads.  This emulates what
+	 * do_mpage_read_folio does.
+	 */
+	bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ, gfp);
+	if (!bio)
+		bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
+	if (ctx->rac)
+		bio->bi_opf |= REQ_RAHEAD;
+	bio->bi_iter.bi_sector = iomap_sector(iomap, iter->pos);
+	bio->bi_end_io = iomap_read_end_io;
+	bio_add_folio_nofail(bio, folio, plen,
+			offset_in_folio(folio, iter->pos));
+	ctx->read_ctx = bio;
+}
+
+static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
+		struct iomap_read_folio_ctx *ctx, size_t plen)
+{
+	struct folio *folio = ctx->cur_folio;
+	struct bio *bio = ctx->read_ctx;
 
-		if (ctx->rac) /* same as readahead_gfp_mask */
-			gfp |= __GFP_NORETRY | __GFP_NOWARN;
-		bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
-				     gfp);
-		/*
-		 * If the bio_alloc fails, try it again for a single page to
-		 * avoid having to deal with partial page reads.  This emulates
-		 * what do_mpage_read_folio does.
-		 */
-		if (!bio)
-			bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
-		if (ctx->rac)
-			bio->bi_opf |= REQ_RAHEAD;
-		bio->bi_iter.bi_sector = sector;
-		bio->bi_end_io = iomap_read_end_io;
-		bio_add_folio_nofail(bio, folio, plen, poff);
-		ctx->read_ctx = bio;
-	}
+	if (!bio ||
+	    bio_end_sector(bio) != iomap_sector(&iter->iomap, iter->pos) ||
+	    !bio_add_folio(bio, folio, plen, offset_in_folio(folio, iter->pos)))
+		iomap_read_alloc_bio(iter, ctx, plen);
 	return 0;
 }
 
-- 
2.47.3

[PATCH 09/16] iomap: pass the iomap_iter to ->submit_read

[Christoph Hellwig]

This provides additional context for file systems.

Rename the fuse instance to match the method name while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/fuse/file.c         | 5 +++--
 fs/iomap/bio.c         | 3 ++-
 fs/iomap/buffered-io.c | 4 ++--
 fs/ntfs3/inode.c       | 3 ++-
 include/linux/iomap.h  | 3 ++-
 5 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index b1bb7153cb78..a9c836d7f586 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -947,7 +947,8 @@ static int fuse_iomap_read_folio_range_async(const struct iomap_iter *iter,
 	return ret;
 }
 
-static void fuse_iomap_read_submit(struct iomap_read_folio_ctx *ctx)
+static void fuse_iomap_submit_read(const struct iomap_iter *iter,
+		struct iomap_read_folio_ctx *ctx)
 {
 	struct fuse_fill_read_data *data = ctx->read_ctx;
 
@@ -958,7 +959,7 @@ static void fuse_iomap_read_submit(struct iomap_read_folio_ctx *ctx)
 
 static const struct iomap_read_ops fuse_iomap_read_ops = {
 	.read_folio_range = fuse_iomap_read_folio_range_async,
-	.submit_read = fuse_iomap_read_submit,
+	.submit_read = fuse_iomap_submit_read,
 };
 
 static int fuse_read_folio(struct file *file, struct folio *folio)
diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index 578b1202e037..cb60d1facb5a 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -18,7 +18,8 @@ static void iomap_read_end_io(struct bio *bio)
 	bio_put(bio);
 }
 
-static void iomap_bio_submit_read(struct iomap_read_folio_ctx *ctx)
+static void iomap_bio_submit_read(const struct iomap_iter *iter,
+		struct iomap_read_folio_ctx *ctx)
 {
 	struct bio *bio = ctx->read_ctx;
 
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index a0c46aadb97d..763b266f38c5 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -588,7 +588,7 @@ void iomap_read_folio(const struct iomap_ops *ops,
 				&bytes_submitted);
 
 	if (ctx->ops->submit_read)
-		ctx->ops->submit_read(ctx);
+		ctx->ops->submit_read(&iter, ctx);
 
 	if (ctx->cur_folio)
 		iomap_read_end(ctx->cur_folio, bytes_submitted);
@@ -654,7 +654,7 @@ void iomap_readahead(const struct iomap_ops *ops,
 					&cur_bytes_submitted);
 
 	if (ctx->ops->submit_read)
-		ctx->ops->submit_read(ctx);
+		ctx->ops->submit_read(&iter, ctx);
 
 	if (ctx->cur_folio)
 		iomap_read_end(ctx->cur_folio, cur_bytes_submitted);
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 6e65066ebcc1..511967ef7ec9 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -651,7 +651,8 @@ static int ntfs_iomap_bio_read_folio_range(const struct iomap_iter *iter,
 	return 0;
 }
 
-static void ntfs_iomap_bio_submit_read(struct iomap_read_folio_ctx *ctx)
+static void ntfs_iomap_bio_submit_read(const struct iomap_iter *iter,
+		struct iomap_read_folio_ctx *ctx)
 {
 	struct bio *bio = ctx->read_ctx;
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 99b7209dabd7..6fbe121e2adf 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -512,7 +512,8 @@ struct iomap_read_ops {
 	 *
 	 * This is optional.
 	 */
-	void (*submit_read)(struct iomap_read_folio_ctx *ctx);
+	void (*submit_read)(const struct iomap_iter *iter,
+			struct iomap_read_folio_ctx *ctx);
 };
 
 /*
-- 
2.47.3

[PATCH 10/16] iomap: only call into ->submit_read when there is a read_ctx

[Christoph Hellwig]

Move the NULL check into the callers to simplify the callees.

Fuse was missing this before, but has a constant read_ctx that is
never NULL or changed, so no change here either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c         | 5 +----
 fs/iomap/buffered-io.c | 4 ++--
 fs/ntfs3/inode.c       | 3 +--
 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index cb60d1facb5a..80bbd328bd3c 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -21,10 +21,7 @@ static void iomap_read_end_io(struct bio *bio)
 static void iomap_bio_submit_read(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx)
 {
-	struct bio *bio = ctx->read_ctx;
-
-	if (bio)
-		submit_bio(bio);
+	submit_bio(ctx->read_ctx);
 }
 
 static void iomap_read_alloc_bio(const struct iomap_iter *iter,
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 763b266f38c5..51a58a0bfe6c 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -587,7 +587,7 @@ void iomap_read_folio(const struct iomap_ops *ops,
 		iter.status = iomap_read_folio_iter(&iter, ctx,
 				&bytes_submitted);
 
-	if (ctx->ops->submit_read)
+	if (ctx->read_ctx && ctx->ops->submit_read)
 		ctx->ops->submit_read(&iter, ctx);
 
 	if (ctx->cur_folio)
@@ -653,7 +653,7 @@ void iomap_readahead(const struct iomap_ops *ops,
 		iter.status = iomap_readahead_iter(&iter, ctx,
 					&cur_bytes_submitted);
 
-	if (ctx->ops->submit_read)
+	if (ctx->read_ctx && ctx->ops->submit_read)
 		ctx->ops->submit_read(&iter, ctx);
 
 	if (ctx->cur_folio)
diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 511967ef7ec9..7ab4e18f8013 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -656,8 +656,7 @@ static void ntfs_iomap_bio_submit_read(const struct iomap_iter *iter,
 {
 	struct bio *bio = ctx->read_ctx;
 
-	if (bio)
-		submit_bio(bio);
+	submit_bio(bio);
 }
 
 static const struct iomap_read_ops ntfs_iomap_bio_read_ops = {
-- 
2.47.3

[PATCH 11/16] iomap: allow file systems to hook into buffered read bio submission

[Christoph Hellwig]

File systems such as btrfs have additional operations with bios such as
verifying data checksums.  Allow file systems to hook into submission
of the bio to allow for this processing by replacing the direct
submit_bio call in iomap_read_alloc_bio with a call into ->submit_read
and exporting iomap_read_alloc_bio.  Also add a new field to
struct iomap_read_folio_ctx to track the file logic offset of the current
read context.

Based on a patch from Goldwyn Rodrigues <rgoldwyn@suse.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c        | 15 +++++++++------
 include/linux/iomap.h |  4 ++++
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index 80bbd328bd3c..903cb9fe759e 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -32,10 +32,11 @@ static void iomap_read_alloc_bio(const struct iomap_iter *iter,
 	struct folio *folio = ctx->cur_folio;
 	gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
 	gfp_t orig_gfp = gfp;
-	struct bio *bio = ctx->read_ctx;
+	struct bio *bio;
 
-	if (bio)
-		submit_bio(bio);
+	/* Submit the existing range if there was one. */
+	if (ctx->read_ctx)
+		ctx->ops->submit_read(iter, ctx);
 
 	/* Same as readahead_gfp_mask: */
 	if (ctx->rac)
@@ -56,9 +57,10 @@ static void iomap_read_alloc_bio(const struct iomap_iter *iter,
 	bio_add_folio_nofail(bio, folio, plen,
 			offset_in_folio(folio, iter->pos));
 	ctx->read_ctx = bio;
+	ctx->read_ctx_file_offset = iter->pos;
 }
 
-static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
+int iomap_bio_read_folio_range(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx, size_t plen)
 {
 	struct folio *folio = ctx->cur_folio;
@@ -70,10 +72,11 @@ static int iomap_bio_read_folio_range(const struct iomap_iter *iter,
 		iomap_read_alloc_bio(iter, ctx, plen);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(iomap_bio_read_folio_range);
 
 const struct iomap_read_ops iomap_bio_read_ops = {
-	.read_folio_range = iomap_bio_read_folio_range,
-	.submit_read = iomap_bio_submit_read,
+	.read_folio_range	= iomap_bio_read_folio_range,
+	.submit_read		= iomap_bio_submit_read,
 };
 EXPORT_SYMBOL_GPL(iomap_bio_read_ops);
 
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6fbe121e2adf..b2b9e649a3b8 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -493,6 +493,7 @@ struct iomap_read_folio_ctx {
 	struct folio		*cur_folio;
 	struct readahead_control *rac;
 	void			*read_ctx;
+	loff_t			read_ctx_file_offset;
 };
 
 struct iomap_read_ops {
@@ -599,6 +600,9 @@ int iomap_swapfile_activate(struct swap_info_struct *sis,
 extern struct bio_set iomap_ioend_bioset;
 
 #ifdef CONFIG_BLOCK
+int iomap_bio_read_folio_range(const struct iomap_iter *iter,
+		struct iomap_read_folio_ctx *ctx, size_t plen);
+
 extern const struct iomap_read_ops iomap_bio_read_ops;
 
 static inline void iomap_bio_read_folio(struct folio *folio,
-- 
2.47.3

[PATCH 12/16] ntfs3: remove copy and pasted iomap code

[Christoph Hellwig]

ntfs3 copied the iomap code without attribution or talking to the
maintainers, to hook into the bio completion for (unexplained) zeroing.

Fix this by just overriding the bio completion handler in the submit
handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/ntfs3/inode.c | 51 +++---------------------------------------------
 1 file changed, 3 insertions(+), 48 deletions(-)

diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 7ab4e18f8013..60af9f8e0366 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -605,63 +605,18 @@ static void ntfs_iomap_read_end_io(struct bio *bio)
 	bio_put(bio);
 }
 
-/*
- * Copied from iomap/bio.c.
- */
-static int ntfs_iomap_bio_read_folio_range(const struct iomap_iter *iter,
-					   struct iomap_read_folio_ctx *ctx,
-					   size_t plen)
-{
-	struct folio *folio = ctx->cur_folio;
-	const struct iomap *iomap = &iter->iomap;
-	loff_t pos = iter->pos;
-	size_t poff = offset_in_folio(folio, pos);
-	loff_t length = iomap_length(iter);
-	sector_t sector;
-	struct bio *bio = ctx->read_ctx;
-
-	sector = iomap_sector(iomap, pos);
-	if (!bio || bio_end_sector(bio) != sector ||
-	    !bio_add_folio(bio, folio, plen, poff)) {
-		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
-		gfp_t orig_gfp = gfp;
-		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
-
-		if (bio)
-			submit_bio(bio);
-
-		if (ctx->rac) /* same as readahead_gfp_mask */
-			gfp |= __GFP_NORETRY | __GFP_NOWARN;
-		bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
-				gfp);
-		/*
-		 * If the bio_alloc fails, try it again for a single page to
-		 * avoid having to deal with partial page reads.  This emulates
-		 * what do_mpage_read_folio does.
-		 */
-		if (!bio)
-			bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
-		if (ctx->rac)
-			bio->bi_opf |= REQ_RAHEAD;
-		bio->bi_iter.bi_sector = sector;
-		bio->bi_end_io = ntfs_iomap_read_end_io;
-		bio_add_folio_nofail(bio, folio, plen, poff);
-		ctx->read_ctx = bio;
-	}
-	return 0;
-}
-
 static void ntfs_iomap_bio_submit_read(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx)
 {
 	struct bio *bio = ctx->read_ctx;
 
+	bio->bi_end_io = ntfs_iomap_read_end_io;
 	submit_bio(bio);
 }
 
 static const struct iomap_read_ops ntfs_iomap_bio_read_ops = {
-	.read_folio_range = ntfs_iomap_bio_read_folio_range,
-	.submit_read = ntfs_iomap_bio_submit_read,
+	.read_folio_range	= iomap_bio_read_folio_range,
+	.submit_read		= ntfs_iomap_bio_submit_read,
 };
 
 static int ntfs_read_folio(struct file *file, struct folio *folio)
-- 
2.47.3

[PATCH 13/16] iomap: add a bioset pointer to iomap_read_folio_ops

[Christoph Hellwig]

Optionally allocate the bio from the bioset provided in
iomap_read_folio_ops.  If no bioset is provided, fs_bio_set is still
used, which is the standard bioset for file systems.

Based on a patch from Goldwyn Rodrigues <rgoldwyn@suse.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c        | 14 ++++++++++++--
 include/linux/iomap.h |  6 ++++++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index 903cb9fe759e..259a2bf95a43 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -24,11 +24,19 @@ static void iomap_bio_submit_read(const struct iomap_iter *iter,
 	submit_bio(ctx->read_ctx);
 }
 
+static struct bio_set *iomap_read_bio_set(struct iomap_read_folio_ctx *ctx)
+{
+	if (ctx->ops && ctx->ops->bio_set)
+		return ctx->ops->bio_set;
+	return &fs_bio_set;
+}
+
 static void iomap_read_alloc_bio(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx, size_t plen)
 {
 	const struct iomap *iomap = &iter->iomap;
 	unsigned int nr_vecs = DIV_ROUND_UP(iomap_length(iter), PAGE_SIZE);
+	struct bio_set *bio_set = iomap_read_bio_set(ctx);
 	struct folio *folio = ctx->cur_folio;
 	gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
 	gfp_t orig_gfp = gfp;
@@ -47,9 +55,11 @@ static void iomap_read_alloc_bio(const struct iomap_iter *iter,
 	 * having to deal with partial page reads.  This emulates what
 	 * do_mpage_read_folio does.
 	 */
-	bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ, gfp);
+	bio = bio_alloc_bioset(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
+			gfp, bio_set);
 	if (!bio)
-		bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
+		bio = bio_alloc_bioset(iomap->bdev, 1, REQ_OP_READ, orig_gfp,
+				bio_set);
 	if (ctx->rac)
 		bio->bi_opf |= REQ_RAHEAD;
 	bio->bi_iter.bi_sector = iomap_sector(iomap, iter->pos);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index b2b9e649a3b8..387a1174522f 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -515,6 +515,12 @@ struct iomap_read_ops {
 	 */
 	void (*submit_read)(const struct iomap_iter *iter,
 			struct iomap_read_folio_ctx *ctx);
+
+	/*
+	 * Optional, allows filesystem to specify own bio_set, so new bio's
+	 * can be allocated from the provided bio_set.
+	 */
+	struct bio_set *bio_set;
 };
 
 /*
-- 
2.47.3

[PATCH 14/16] iomap: support ioends for buffered reads

[Christoph Hellwig]

Support using the ioend structure to defer I/O completion for
buffered reads by calling into the buffered read I/O completion
handler from iomap_finish_ioend.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c      | 19 ++++++++++++++++---
 fs/iomap/internal.h |  1 +
 fs/iomap/ioend.c    |  8 +++++---
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index 259a2bf95a43..b4de67bdd513 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -8,14 +8,27 @@
 #include "internal.h"
 #include "trace.h"
 
-static void iomap_read_end_io(struct bio *bio)
+static u32 __iomap_read_end_io(struct bio *bio, int error)
 {
-	int error = blk_status_to_errno(bio->bi_status);
 	struct folio_iter fi;
+	u32 folio_count = 0;
 
-	bio_for_each_folio_all(fi, bio)
+	bio_for_each_folio_all(fi, bio) {
 		iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
+		folio_count++;
+	}
 	bio_put(bio);
+	return folio_count;
+}
+
+static void iomap_read_end_io(struct bio *bio)
+{
+	__iomap_read_end_io(bio, blk_status_to_errno(bio->bi_status));
+}
+
+u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend)
+{
+	return __iomap_read_end_io(&ioend->io_bio, ioend->io_error);
 }
 
 static void iomap_bio_submit_read(const struct iomap_iter *iter,
diff --git a/fs/iomap/internal.h b/fs/iomap/internal.h
index 3a4e4aad2bd1..b39dbc17e3f0 100644
--- a/fs/iomap/internal.h
+++ b/fs/iomap/internal.h
@@ -4,6 +4,7 @@
 
 #define IOEND_BATCH_SIZE	4096
 
+u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend);
 u32 iomap_finish_ioend_direct(struct iomap_ioend *ioend);
 
 #ifdef CONFIG_BLOCK
diff --git a/fs/iomap/ioend.c b/fs/iomap/ioend.c
index e4d57cb969f1..c6b6cd0f2fdd 100644
--- a/fs/iomap/ioend.c
+++ b/fs/iomap/ioend.c
@@ -37,7 +37,7 @@ EXPORT_SYMBOL_GPL(iomap_init_ioend);
  * state, release holds on bios, and finally free up memory.  Do not use the
  * ioend after this.
  */
-static u32 iomap_finish_ioend_buffered(struct iomap_ioend *ioend)
+static u32 iomap_finish_ioend_buffered_write(struct iomap_ioend *ioend)
 {
 	struct inode *inode = ioend->io_inode;
 	struct bio *bio = &ioend->io_bio;
@@ -74,7 +74,7 @@ static void ioend_writeback_end_bio(struct bio *bio)
 	struct iomap_ioend *ioend = iomap_ioend_from_bio(bio);
 
 	ioend->io_error = blk_status_to_errno(bio->bi_status);
-	iomap_finish_ioend_buffered(ioend);
+	iomap_finish_ioend_buffered_write(ioend);
 }
 
 /*
@@ -266,7 +266,9 @@ static u32 iomap_finish_ioend(struct iomap_ioend *ioend, int error)
 		return 0;
 	if (ioend->io_flags & IOMAP_IOEND_DIRECT)
 		return iomap_finish_ioend_direct(ioend);
-	return iomap_finish_ioend_buffered(ioend);
+	if (bio_op(&ioend->io_bio) == REQ_OP_READ)
+		return iomap_finish_ioend_buffered_read(ioend);
+	return iomap_finish_ioend_buffered_write(ioend);
 }
 
 /*
-- 
2.47.3

[PATCH 15/16] iomap: support T10 protection information

[Christoph Hellwig]

Add support for generating / verifying protection information in iomap.
This is done by hooking into the bio submission and then using the
generic PI helpers.  Compared to just using the block layer auto PI
this extends the protection envelope and also prepares for eventually
passing through PI from userspace at least for direct I/O.

To generate or verify PI, the file system needs to set the
IOMAP_F_INTEGRITY flag on the iomap for the request, and ensure the
ioends are used for all integrity I/O.  Additionally the file system
must defer read I/O completions to user context so that the guard
tag validation isn't run from interrupt context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/iomap/bio.c        | 24 +++++++++++++++++++++---
 fs/iomap/direct-io.c  | 15 ++++++++++++++-
 fs/iomap/internal.h   | 13 +++++++++++++
 fs/iomap/ioend.c      | 20 ++++++++++++++++++--
 include/linux/iomap.h |  7 +++++++
 5 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/fs/iomap/bio.c b/fs/iomap/bio.c
index b4de67bdd513..f989ffcaac96 100644
--- a/fs/iomap/bio.c
+++ b/fs/iomap/bio.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2010 Red Hat, Inc.
  * Copyright (C) 2016-2023 Christoph Hellwig.
  */
+#include <linux/bio-integrity.h>
 #include <linux/iomap.h>
 #include <linux/pagemap.h>
 #include "internal.h"
@@ -17,6 +18,8 @@ static u32 __iomap_read_end_io(struct bio *bio, int error)
 		iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
 		folio_count++;
 	}
+	if (bio_integrity(bio))
+		fs_bio_integrity_free(bio);
 	bio_put(bio);
 	return folio_count;
 }
@@ -34,7 +37,11 @@ u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend)
 static void iomap_bio_submit_read(const struct iomap_iter *iter,
 		struct iomap_read_folio_ctx *ctx)
 {
-	submit_bio(ctx->read_ctx);
+	struct bio *bio = ctx->read_ctx;
+
+	if (iter->iomap.flags & IOMAP_F_INTEGRITY)
+		fs_bio_integrity_alloc(bio);
+	submit_bio(bio);
 }
 
 static struct bio_set *iomap_read_bio_set(struct iomap_read_folio_ctx *ctx)
@@ -91,6 +98,7 @@ int iomap_bio_read_folio_range(const struct iomap_iter *iter,
 
 	if (!bio ||
 	    bio_end_sector(bio) != iomap_sector(&iter->iomap, iter->pos) ||
+	    bio->bi_iter.bi_size > iomap_max_bio_size(&iter->iomap) - plen ||
 	    !bio_add_folio(bio, folio, plen, offset_in_folio(folio, iter->pos)))
 		iomap_read_alloc_bio(iter, ctx, plen);
 	return 0;
@@ -107,11 +115,21 @@ int iomap_bio_read_folio_range_sync(const struct iomap_iter *iter,
 		struct folio *folio, loff_t pos, size_t len)
 {
 	const struct iomap *srcmap = iomap_iter_srcmap(iter);
+	sector_t sector = iomap_sector(srcmap, pos);
 	struct bio_vec bvec;
 	struct bio bio;
+	int error;
 
 	bio_init(&bio, srcmap->bdev, &bvec, 1, REQ_OP_READ);
-	bio.bi_iter.bi_sector = iomap_sector(srcmap, pos);
+	bio.bi_iter.bi_sector = sector;
 	bio_add_folio_nofail(&bio, folio, len, offset_in_folio(folio, pos));
-	return submit_bio_wait(&bio);
+	if (srcmap->flags & IOMAP_F_INTEGRITY)
+		fs_bio_integrity_alloc(&bio);
+	error = submit_bio_wait(&bio);
+	if (srcmap->flags & IOMAP_F_INTEGRITY) {
+		if (!error)
+			error = fs_bio_integrity_verify(&bio, sector, len);
+		fs_bio_integrity_free(&bio);
+	}
+	return error;
 }
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 21d4fad2eeb8..264374966202 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2010 Red Hat, Inc.
  * Copyright (c) 2016-2025 Christoph Hellwig.
  */
+#include <linux/bio-integrity.h>
 #include <linux/blk-crypto.h>
 #include <linux/fscrypt.h>
 #include <linux/pagemap.h>
@@ -227,6 +228,9 @@ static void __iomap_dio_bio_end_io(struct bio *bio, bool inline_completion)
 {
 	struct iomap_dio *dio = bio->bi_private;
 
+	if (bio_integrity(bio))
+		fs_bio_integrity_free(bio);
+
 	if (dio->flags & IOMAP_DIO_BOUNCE) {
 		bio_iov_iter_unbounce(bio, !!dio->error,
 				dio->flags & IOMAP_DIO_USER_BACKED);
@@ -337,8 +341,10 @@ static ssize_t iomap_dio_bio_iter_one(struct iomap_iter *iter,
 	bio->bi_private = dio;
 	bio->bi_end_io = iomap_dio_bio_end_io;
 
+
 	if (dio->flags & IOMAP_DIO_BOUNCE)
-		ret = bio_iov_iter_bounce(bio, dio->submit.iter, BIO_MAX_SIZE);
+		ret = bio_iov_iter_bounce(bio, dio->submit.iter,
+				iomap_max_bio_size(&iter->iomap));
 	else
 		ret = bio_iov_iter_get_pages(bio, dio->submit.iter,
 					     alignment - 1);
@@ -355,6 +361,13 @@ static ssize_t iomap_dio_bio_iter_one(struct iomap_iter *iter,
 		goto out_put_bio;
 	}
 
+	if (iter->iomap.flags & IOMAP_F_INTEGRITY) {
+		if (dio->flags & IOMAP_DIO_WRITE)
+			fs_bio_integrity_generate(bio);
+		else
+			fs_bio_integrity_alloc(bio);
+	}
+
 	if (dio->flags & IOMAP_DIO_WRITE)
 		task_io_account_write(ret);
 	else if ((dio->flags & IOMAP_DIO_USER_BACKED) &&
diff --git a/fs/iomap/internal.h b/fs/iomap/internal.h
index b39dbc17e3f0..74e898b196dc 100644
--- a/fs/iomap/internal.h
+++ b/fs/iomap/internal.h
@@ -4,6 +4,19 @@
 
 #define IOEND_BATCH_SIZE	4096
 
+/*
+ * Normally we can build bios as big as the data structure supports.
+ *
+ * But for integrity protected I/O we need to respect the maximum size of the
+ * single contiguous allocation for the integrity buffer.
+ */
+static inline size_t iomap_max_bio_size(const struct iomap *iomap)
+{
+	if (iomap->flags & IOMAP_F_INTEGRITY)
+		return max_integrity_io_size(bdev_limits(iomap->bdev));
+	return BIO_MAX_SIZE;
+}
+
 u32 iomap_finish_ioend_buffered_read(struct iomap_ioend *ioend);
 u32 iomap_finish_ioend_direct(struct iomap_ioend *ioend);
 
diff --git a/fs/iomap/ioend.c b/fs/iomap/ioend.c
index c6b6cd0f2fdd..bf251d206f50 100644
--- a/fs/iomap/ioend.c
+++ b/fs/iomap/ioend.c
@@ -2,6 +2,7 @@
 /*
  * Copyright (c) 2016-2025 Christoph Hellwig.
  */
+#include <linux/bio-integrity.h>
 #include <linux/iomap.h>
 #include <linux/list_sort.h>
 #include <linux/pagemap.h>
@@ -65,6 +66,8 @@ static u32 iomap_finish_ioend_buffered_write(struct iomap_ioend *ioend)
 		folio_count++;
 	}
 
+	if (bio_integrity(bio))
+		fs_bio_integrity_free(bio);
 	bio_put(bio);	/* frees the ioend */
 	return folio_count;
 }
@@ -98,6 +101,8 @@ int iomap_ioend_writeback_submit(struct iomap_writepage_ctx *wpc, int error)
 		return error;
 	}
 
+	if (wpc->iomap.flags & IOMAP_F_INTEGRITY)
+		fs_bio_integrity_generate(&ioend->io_bio);
 	submit_bio(&ioend->io_bio);
 	return 0;
 }
@@ -119,10 +124,13 @@ static struct iomap_ioend *iomap_alloc_ioend(struct iomap_writepage_ctx *wpc,
 }
 
 static bool iomap_can_add_to_ioend(struct iomap_writepage_ctx *wpc, loff_t pos,
-		u16 ioend_flags)
+		unsigned int map_len, u16 ioend_flags)
 {
 	struct iomap_ioend *ioend = wpc->wb_ctx;
 
+	if (ioend->io_bio.bi_iter.bi_size >
+	    iomap_max_bio_size(&wpc->iomap) - map_len)
+		return false;
 	if (ioend_flags & IOMAP_IOEND_BOUNDARY)
 		return false;
 	if ((ioend_flags & IOMAP_IOEND_NOMERGE_FLAGS) !=
@@ -187,7 +195,7 @@ ssize_t iomap_add_to_ioend(struct iomap_writepage_ctx *wpc, struct folio *folio,
 	if (pos == wpc->iomap.offset && (wpc->iomap.flags & IOMAP_F_BOUNDARY))
 		ioend_flags |= IOMAP_IOEND_BOUNDARY;
 
-	if (!ioend || !iomap_can_add_to_ioend(wpc, pos, ioend_flags)) {
+	if (!ioend || !iomap_can_add_to_ioend(wpc, pos, map_len, ioend_flags)) {
 new_ioend:
 		if (ioend) {
 			error = wpc->ops->writeback_submit(wpc, 0);
@@ -264,6 +272,14 @@ static u32 iomap_finish_ioend(struct iomap_ioend *ioend, int error)
 
 	if (!atomic_dec_and_test(&ioend->io_remaining))
 		return 0;
+
+	if (!ioend->io_error &&
+	    bio_integrity(&ioend->io_bio) &&
+	    bio_op(&ioend->io_bio) == REQ_OP_READ) {
+		ioend->io_error = fs_bio_integrity_verify(&ioend->io_bio,
+			ioend->io_sector, ioend->io_size);
+	}
+
 	if (ioend->io_flags & IOMAP_IOEND_DIRECT)
 		return iomap_finish_ioend_direct(ioend);
 	if (bio_op(&ioend->io_bio) == REQ_OP_READ)
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 387a1174522f..531f9ebdeeae 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -65,6 +65,8 @@ struct vm_fault;
  *
  * IOMAP_F_ATOMIC_BIO indicates that (write) I/O will be issued as an atomic
  * bio, i.e. set REQ_ATOMIC.
+ *
+ * IOMAP_F_INTEGRITY indicates that the filesystems handles integrity metadata.
  */
 #define IOMAP_F_NEW		(1U << 0)
 #define IOMAP_F_DIRTY		(1U << 1)
@@ -79,6 +81,11 @@ struct vm_fault;
 #define IOMAP_F_BOUNDARY	(1U << 6)
 #define IOMAP_F_ANON_WRITE	(1U << 7)
 #define IOMAP_F_ATOMIC_BIO	(1U << 8)
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+#define IOMAP_F_INTEGRITY	(1U << 9)
+#else
+#define IOMAP_F_INTEGRITY	0
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 /*
  * Flag reserved for file system specific usage
-- 
2.47.3

[PATCH 16/16] xfs: support T10 protection information

[Christoph Hellwig]

Add support for generating / verifying protection information in the file
system.  This is largely done by simply setting the IOMAP_F_INTEGRITY
flag and letting iomap do all of the work.  XFS just has to ensure that
the data read completions for integrity data are run from user context.

For zoned writeback, XFS also has to generate the integrity data itself
as the zoned writeback path is not using the generic writeback_submit
implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
---
 fs/xfs/xfs_aops.c  | 47 ++++++++++++++++++++++++++++++++++++++++++----
 fs/xfs/xfs_iomap.c |  9 ++++++---
 2 files changed, 49 insertions(+), 7 deletions(-)

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 76678814f46f..f279055fcea0 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -22,6 +22,7 @@
 #include "xfs_icache.h"
 #include "xfs_zone_alloc.h"
 #include "xfs_rtgroup.h"
+#include <linux/bio-integrity.h>
 
 struct xfs_writepage_ctx {
 	struct iomap_writepage_ctx ctx;
@@ -661,6 +662,8 @@ xfs_zoned_writeback_submit(
 		bio_endio(&ioend->io_bio);
 		return error;
 	}
+	if (wpc->iomap.flags & IOMAP_F_INTEGRITY)
+		fs_bio_integrity_generate(&ioend->io_bio);
 	xfs_zone_alloc_and_submit(ioend, &XFS_ZWPC(wpc)->open_zone);
 	return 0;
 }
@@ -741,12 +744,45 @@ xfs_vm_bmap(
 	return iomap_bmap(mapping, block, &xfs_read_iomap_ops);
 }
 
+static void
+xfs_bio_submit_read(
+	const struct iomap_iter		*iter,
+	struct iomap_read_folio_ctx	*ctx)
+{
+	struct bio			*bio = ctx->read_ctx;
+
+	/* defer read completions to the ioend workqueue */
+	iomap_init_ioend(iter->inode, bio, ctx->read_ctx_file_offset, 0);
+	bio->bi_end_io = xfs_end_bio;
+	submit_bio(bio);
+}
+
+static const struct iomap_read_ops xfs_iomap_read_ops = {
+	.read_folio_range	= iomap_bio_read_folio_range,
+	.submit_read		= xfs_bio_submit_read,
+	.bio_set		= &iomap_ioend_bioset,
+};
+
+static inline const struct iomap_read_ops *
+xfs_get_iomap_read_ops(
+	const struct address_space	*mapping)
+{
+	struct xfs_inode		*ip = XFS_I(mapping->host);
+
+	if (bdev_has_integrity_csum(xfs_inode_buftarg(ip)->bt_bdev))
+		return &xfs_iomap_read_ops;
+	return &iomap_bio_read_ops;
+}
+
 STATIC int
 xfs_vm_read_folio(
-	struct file		*unused,
-	struct folio		*folio)
+	struct file			*file,
+	struct folio			*folio)
 {
-	iomap_bio_read_folio(folio, &xfs_read_iomap_ops);
+	struct iomap_read_folio_ctx	ctx = { .cur_folio = folio };
+
+	ctx.ops = xfs_get_iomap_read_ops(folio->mapping);
+	iomap_read_folio(&xfs_read_iomap_ops, &ctx, NULL);
 	return 0;
 }
 
@@ -754,7 +790,10 @@ STATIC void
 xfs_vm_readahead(
 	struct readahead_control	*rac)
 {
-	iomap_bio_readahead(rac, &xfs_read_iomap_ops);
+	struct iomap_read_folio_ctx	ctx = { .rac = rac };
+
+	ctx.ops = xfs_get_iomap_read_ops(rac->mapping),
+	iomap_readahead(&xfs_read_iomap_ops, &ctx, NULL);
 }
 
 static int
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index be86d43044df..9c2f12d5fec9 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -143,11 +143,14 @@ xfs_bmbt_to_iomap(
 	}
 	iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff);
 	iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
-	if (mapping_flags & IOMAP_DAX)
+	iomap->flags = iomap_flags;
+	if (mapping_flags & IOMAP_DAX) {
 		iomap->dax_dev = target->bt_daxdev;
-	else
+	} else {
 		iomap->bdev = target->bt_bdev;
-	iomap->flags = iomap_flags;
+		if (bdev_has_integrity_csum(iomap->bdev))
+			iomap->flags |= IOMAP_F_INTEGRITY;
+	}
 
 	/*
 	 * If the inode is dirty for datasync purposes, let iomap know so it
-- 
2.47.3

Re: [PATCH 12/16] ntfs3: remove copy and pasted iomap code

[Darrick J. Wong]

On Mon, Feb 23, 2026 at 05:20:12AM -0800, Christoph Hellwig wrote:
> ntfs3 copied the iomap code without attribution or talking to the
> maintainers, to hook into the bio completion for (unexplained) zeroing.

Well they /did/ attribute it...

> Fix this by just overriding the bio completion handler in the submit
> handler.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  fs/ntfs3/inode.c | 51 +++---------------------------------------------
>  1 file changed, 3 insertions(+), 48 deletions(-)
> 
> diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
> index 7ab4e18f8013..60af9f8e0366 100644
> --- a/fs/ntfs3/inode.c
> +++ b/fs/ntfs3/inode.c
> @@ -605,63 +605,18 @@ static void ntfs_iomap_read_end_io(struct bio *bio)
>  	bio_put(bio);
>  }
>  
> -/*
> - * Copied from iomap/bio.c.

...extremely poorly, by not recording their reasons for copy-pasting the
code.

> - */
> -static int ntfs_iomap_bio_read_folio_range(const struct iomap_iter *iter,
> -					   struct iomap_read_folio_ctx *ctx,
> -					   size_t plen)
> -{
> -	struct folio *folio = ctx->cur_folio;
> -	const struct iomap *iomap = &iter->iomap;
> -	loff_t pos = iter->pos;
> -	size_t poff = offset_in_folio(folio, pos);
> -	loff_t length = iomap_length(iter);
> -	sector_t sector;
> -	struct bio *bio = ctx->read_ctx;
> -
> -	sector = iomap_sector(iomap, pos);
> -	if (!bio || bio_end_sector(bio) != sector ||
> -	    !bio_add_folio(bio, folio, plen, poff)) {
> -		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
> -		gfp_t orig_gfp = gfp;
> -		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
> -
> -		if (bio)
> -			submit_bio(bio);
> -
> -		if (ctx->rac) /* same as readahead_gfp_mask */
> -			gfp |= __GFP_NORETRY | __GFP_NOWARN;
> -		bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
> -				gfp);
> -		/*
> -		 * If the bio_alloc fails, try it again for a single page to
> -		 * avoid having to deal with partial page reads.  This emulates
> -		 * what do_mpage_read_folio does.
> -		 */
> -		if (!bio)
> -			bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
> -		if (ctx->rac)
> -			bio->bi_opf |= REQ_RAHEAD;
> -		bio->bi_iter.bi_sector = sector;
> -		bio->bi_end_io = ntfs_iomap_read_end_io;
> -		bio_add_folio_nofail(bio, folio, plen, poff);
> -		ctx->read_ctx = bio;
> -	}
> -	return 0;
> -}

Yeah, identical to iomap_bio_read_folio_range except for setting
bi_end_io.

Don't copy-paste stuff.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> -
>  static void ntfs_iomap_bio_submit_read(const struct iomap_iter *iter,
>  		struct iomap_read_folio_ctx *ctx)
>  {
>  	struct bio *bio = ctx->read_ctx;
>  
> +	bio->bi_end_io = ntfs_iomap_read_end_io;
>  	submit_bio(bio);
>  }
>  
>  static const struct iomap_read_ops ntfs_iomap_bio_read_ops = {
> -	.read_folio_range = ntfs_iomap_bio_read_folio_range,
> -	.submit_read = ntfs_iomap_bio_submit_read,
> +	.read_folio_range	= iomap_bio_read_folio_range,
> +	.submit_read		= ntfs_iomap_bio_submit_read,
>  };
>  
>  static int ntfs_read_folio(struct file *file, struct folio *folio)
> -- 
> 2.47.3
> 
> 

Re: [PATCH 12/16] ntfs3: remove copy and pasted iomap code

[Konstantin Komarov]

On 2/23/26 14:20, Christoph Hellwig wrote:

> ntfs3 copied the iomap code without attribution or talking to the
> maintainers, to hook into the bio completion for (unexplained) zeroing.
>
> Fix this by just overriding the bio completion handler in the submit
> handler.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   fs/ntfs3/inode.c | 51 +++---------------------------------------------
>   1 file changed, 3 insertions(+), 48 deletions(-)
>
> diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
> index 7ab4e18f8013..60af9f8e0366 100644
> --- a/fs/ntfs3/inode.c
> +++ b/fs/ntfs3/inode.c
> @@ -605,63 +605,18 @@ static void ntfs_iomap_read_end_io(struct bio *bio)
>   	bio_put(bio);
>   }
>   
> -/*
> - * Copied from iomap/bio.c.
> - */
> -static int ntfs_iomap_bio_read_folio_range(const struct iomap_iter *iter,
> -					   struct iomap_read_folio_ctx *ctx,
> -					   size_t plen)
> -{
> -	struct folio *folio = ctx->cur_folio;
> -	const struct iomap *iomap = &iter->iomap;
> -	loff_t pos = iter->pos;
> -	size_t poff = offset_in_folio(folio, pos);
> -	loff_t length = iomap_length(iter);
> -	sector_t sector;
> -	struct bio *bio = ctx->read_ctx;
> -
> -	sector = iomap_sector(iomap, pos);
> -	if (!bio || bio_end_sector(bio) != sector ||
> -	    !bio_add_folio(bio, folio, plen, poff)) {
> -		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);
> -		gfp_t orig_gfp = gfp;
> -		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
> -
> -		if (bio)
> -			submit_bio(bio);
> -
> -		if (ctx->rac) /* same as readahead_gfp_mask */
> -			gfp |= __GFP_NORETRY | __GFP_NOWARN;
> -		bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,
> -				gfp);
> -		/*
> -		 * If the bio_alloc fails, try it again for a single page to
> -		 * avoid having to deal with partial page reads.  This emulates
> -		 * what do_mpage_read_folio does.
> -		 */
> -		if (!bio)
> -			bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);
> -		if (ctx->rac)
> -			bio->bi_opf |= REQ_RAHEAD;
> -		bio->bi_iter.bi_sector = sector;
> -		bio->bi_end_io = ntfs_iomap_read_end_io;
> -		bio_add_folio_nofail(bio, folio, plen, poff);
> -		ctx->read_ctx = bio;
> -	}
> -	return 0;
> -}
> -
>   static void ntfs_iomap_bio_submit_read(const struct iomap_iter *iter,
>   		struct iomap_read_folio_ctx *ctx)
>   {
>   	struct bio *bio = ctx->read_ctx;
>   
> +	bio->bi_end_io = ntfs_iomap_read_end_io;
>   	submit_bio(bio);
>   }
>   
>   static const struct iomap_read_ops ntfs_iomap_bio_read_ops = {
> -	.read_folio_range = ntfs_iomap_bio_read_folio_range,
> -	.submit_read = ntfs_iomap_bio_submit_read,
> +	.read_folio_range	= iomap_bio_read_folio_range,
> +	.submit_read		= ntfs_iomap_bio_submit_read,
>   };
>   
>   static int ntfs_read_folio(struct file *file, struct folio *folio)

Hello,

Thanks for the note. The iomap helper was copied because
`iomap_bio_read_folio_range` is defined `static` in iomap/bio.c and thus
not available for reuse; that prevented using the exported helpers in this
tree.

If I’m mistaken, please let me know.

Regards,
Konstantin

Re: support file system generated / verified integrity information v4

[Christian Brauner]

On Mon, 23 Feb 2026 05:20:00 -0800, Christoph Hellwig wrote:
> this series adds support to generate and verify integrity information
> (aka T10 PI) in the file system, instead of the automatic below the
> covers support that is currently used.
> 
> There two reasons for this:
> 
>   a) to increase the protection enveloped.  Right now this is just a
>      minor step from the bottom of the block layer to the file system,
>      but it is required to support io_uring integrity data passthrough in
>      the file system similar to the currently existing support for block
>      devices, which will follow next.  It also allows the file system to
>      directly see the integrity error and act upon in, e.g. when using
>      RAID either integrated (as in btrfs) or by supporting reading
>      redundant copies through the block layer.
>   b) to make the PI processing more efficient.  This is primarily a
>      concern for reads, where the block layer auto PI has to schedule a
>      work item for each bio, and the file system them has to do it again
>      for bounce buffering.  Additionally the current iomap post-I/O
>      workqueue handling is a lot more efficient by supporting merging and
>      avoiding workqueue scheduling storms.
> 
> [...]

Applied to the vfs-7.1.verity branch of the vfs/vfs.git tree.
Patches in the vfs-7.1.verity branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.1.verity

[01/16] block: factor out a bio_integrity_action helper
        https://git.kernel.org/vfs/vfs/c/08163237c7be
[02/16] block: factor out a bio_integrity_setup_default helper
        https://git.kernel.org/vfs/vfs/c/32d5010c428f
[03/16] block: add a bdev_has_integrity_csum helper
        https://git.kernel.org/vfs/vfs/c/840b166bef09
[04/16] block: prepare generation / verification helpers for fs usage
        https://git.kernel.org/vfs/vfs/c/179c2a24466b
[05/16] block: make max_integrity_io_size public
        https://git.kernel.org/vfs/vfs/c/1b9353e52c31
[06/16] block: add fs_bio_integrity helpers
        https://git.kernel.org/vfs/vfs/c/e539fc923425
[07/16] block: pass a maxlen argument to bio_iov_iter_bounce
        https://git.kernel.org/vfs/vfs/c/fc9fc9482061
[08/16] iomap: refactor iomap_bio_read_folio_range
        https://git.kernel.org/vfs/vfs/c/9701407ec63e
[09/16] iomap: pass the iomap_iter to ->submit_read
        https://git.kernel.org/vfs/vfs/c/f11d7d3307f4
[10/16] iomap: only call into ->submit_read when there is a read_ctx
        https://git.kernel.org/vfs/vfs/c/46441138b832
[11/16] iomap: allow file systems to hook into buffered read bio submission
        https://git.kernel.org/vfs/vfs/c/04c2cc5bb77b
[12/16] ntfs3: remove copy and pasted iomap code
        https://git.kernel.org/vfs/vfs/c/4c3906772536
[13/16] iomap: add a bioset pointer to iomap_read_folio_ops
        https://git.kernel.org/vfs/vfs/c/c1dec831dd53
[14/16] iomap: support ioends for buffered reads
        https://git.kernel.org/vfs/vfs/c/9c617c91f801
[15/16] iomap: support T10 protection information
        https://git.kernel.org/vfs/vfs/c/fa1758bda166
[16/16] xfs: support T10 protection information
        https://git.kernel.org/vfs/vfs/c/330cc116c7a0

Re: support file system generated / verified integrity information v4

[Christoph Hellwig]

On Mon, Mar 02, 2026 at 11:11:22AM +0100, Christian Brauner wrote:
> Applied to the vfs-7.1.verity branch of the vfs/vfs.git tree.
> Patches in the vfs-7.1.verity branch should appear in linux-next soon.

Note that the branch name matters much, but this is a different (and
older) use of integrity compare to fsverity/dm-verity.

Re: [PATCH 12/16] ntfs3: remove copy and pasted iomap code

[Christoph Hellwig]

On Fri, Feb 27, 2026 at 02:46:08PM +0100, Konstantin Komarov wrote:
>
> Thanks for the note. The iomap helper was copied because
> `iomap_bio_read_folio_range` is defined `static` in iomap/bio.c and thus
> not available for reuse; that prevented using the exported helpers in this
> tree.

Please talk to maintainers and authors before copy and pasting their
code.  There's usually a better way.

Re: [PATCH 12/16] ntfs3: remove copy and pasted iomap code

[Konstantin Komarov]

On 3/3/26 16:21, Christoph Hellwig wrote:

> On Fri, Feb 27, 2026 at 02:46:08PM +0100, Konstantin Komarov wrote:
>> Thanks for the note. The iomap helper was copied because
>> `iomap_bio_read_folio_range` is defined `static` in iomap/bio.c and thus
>> not available for reuse; that prevented using the exported helpers in this
>> tree.
> Please talk to maintainers and authors before copy and pasting their
> code.  There's usually a better way.
>
Understood. In future I will contact the authors and maintainers before
copying code.

Regards,
Konstantin

Re: support file system generated / verified integrity information v4

[Christian Brauner]

On Mon, Mar 02, 2026 at 05:48:51AM -0800, Christoph Hellwig wrote:
> On Mon, Mar 02, 2026 at 11:11:22AM +0100, Christian Brauner wrote:
> > Applied to the vfs-7.1.verity branch of the vfs/vfs.git tree.
> > Patches in the vfs-7.1.verity branch should appear in linux-next soon.
> 
> Note that the branch name matters much, but this is a different (and
> older) use of integrity compare to fsverity/dm-verity.

Yeah, I know it was mainly named for the related xfs work I had expected
to require some infrastructure work. I'll rename this to
vfs-7.1-integrity which is a bit more generic.

Re: (subset) support file system generated / verified integrity information v4

[Jens Axboe]

On Mon, 23 Feb 2026 05:20:00 -0800, Christoph Hellwig wrote:
> this series adds support to generate and verify integrity information
> (aka T10 PI) in the file system, instead of the automatic below the
> covers support that is currently used.
> 
> There two reasons for this:
> 
>   a) to increase the protection enveloped.  Right now this is just a
>      minor step from the bottom of the block layer to the file system,
>      but it is required to support io_uring integrity data passthrough in
>      the file system similar to the currently existing support for block
>      devices, which will follow next.  It also allows the file system to
>      directly see the integrity error and act upon in, e.g. when using
>      RAID either integrated (as in btrfs) or by supporting reading
>      redundant copies through the block layer.
>   b) to make the PI processing more efficient.  This is primarily a
>      concern for reads, where the block layer auto PI has to schedule a
>      work item for each bio, and the file system them has to do it again
>      for bounce buffering.  Additionally the current iomap post-I/O
>      workqueue handling is a lot more efficient by supporting merging and
>      avoiding workqueue scheduling storms.
> 
> [...]

Applied, thanks!

[01/16] block: factor out a bio_integrity_action helper
        commit: 7ea25eaad5ae3a6c837a3df9bdb822194f002565
[02/16] block: factor out a bio_integrity_setup_default helper
        commit: a936655697cd8d1bab2fd5189e2c33dd6356a266
[03/16] block: add a bdev_has_integrity_csum helper
        commit: 7afe93946dff63aa57c6db81f5eb43ac8233364e
[04/16] block: prepare generation / verification helpers for fs usage
        commit: 3f00626832a9f85fc5a04b25898157a6d43cb236
[05/16] block: make max_integrity_io_size public
        commit: 8c56ef10150ed7650cf4105539242c94c156148c
[06/16] block: add fs_bio_integrity helpers
        commit: 0bde8a12b5540572a7fd6d2867bee6de15e4f289
[07/16] block: pass a maxlen argument to bio_iov_iter_bounce
        commit: a9aa6045abde87b94168c3ba034b953417e27272

Best regards,
-- 
Jens Axboe

Re: (subset) support file system generated / verified integrity information v4

[Christian Brauner]

On Mon, Mar 09, 2026 at 08:52:23AM -0600, Jens Axboe wrote:
> 
> On Mon, 23 Feb 2026 05:20:00 -0800, Christoph Hellwig wrote:
> > this series adds support to generate and verify integrity information
> > (aka T10 PI) in the file system, instead of the automatic below the
> > covers support that is currently used.
> > 
> > There two reasons for this:
> > 
> >   a) to increase the protection enveloped.  Right now this is just a
> >      minor step from the bottom of the block layer to the file system,
> >      but it is required to support io_uring integrity data passthrough in
> >      the file system similar to the currently existing support for block
> >      devices, which will follow next.  It also allows the file system to
> >      directly see the integrity error and act upon in, e.g. when using
> >      RAID either integrated (as in btrfs) or by supporting reading
> >      redundant copies through the block layer.
> >   b) to make the PI processing more efficient.  This is primarily a
> >      concern for reads, where the block layer auto PI has to schedule a
> >      work item for each bio, and the file system them has to do it again
> >      for bounce buffering.  Additionally the current iomap post-I/O
> >      workqueue handling is a lot more efficient by supporting merging and
> >      avoiding workqueue scheduling storms.
> > 
> > [...]
> 
> Applied, thanks!
> 
> [01/16] block: factor out a bio_integrity_action helper
>         commit: 7ea25eaad5ae3a6c837a3df9bdb822194f002565
> [02/16] block: factor out a bio_integrity_setup_default helper
>         commit: a936655697cd8d1bab2fd5189e2c33dd6356a266
> [03/16] block: add a bdev_has_integrity_csum helper
>         commit: 7afe93946dff63aa57c6db81f5eb43ac8233364e
> [04/16] block: prepare generation / verification helpers for fs usage
>         commit: 3f00626832a9f85fc5a04b25898157a6d43cb236
> [05/16] block: make max_integrity_io_size public
>         commit: 8c56ef10150ed7650cf4105539242c94c156148c
> [06/16] block: add fs_bio_integrity helpers
>         commit: 0bde8a12b5540572a7fd6d2867bee6de15e4f289
> [07/16] block: pass a maxlen argument to bio_iov_iter_bounce
>         commit: a9aa6045abde87b94168c3ba034b953417e27272

I've pulled the shared branch and also updated my base to v7.0-rc3 as
per Christoph's request in the other mail.