Merge patch series "io_uring / dio metadata fixes"

Christoph Hellwig <hch@lst.de> says:

Hi all,

while trying to add XFS support for passing through metadata I ran
into a few issues with how that support is wire up for the current
block device use cases, and this fixes it.

* patches from https://lore.kernel.org/20250819082517.2038819-1-hch@lst.de:
  block: don't silently ignore metadata for sync read/write
  fs: add a FMODE_ flag to indicate IOCB_HAS_METADATA availability

Link: https://lore.kernel.org/20250819082517.2038819-1-hch@lst.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

block/fops.c

@@ -7,6 +7,7 @@
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/blkdev.h>
+#include <linux/blk-integrity.h>
 #include <linux/buffer_head.h>
 #include <linux/mpage.h>
 #include <linux/uio.h>
@@ -54,7 +55,6 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
 	struct bio bio;
 	ssize_t ret;
 
-	WARN_ON_ONCE(iocb->ki_flags & IOCB_HAS_METADATA);
 	if (nr_pages <= DIO_INLINE_BIO_VECS)
 		vecs = inline_vecs;
 	else {
@@ -131,7 +131,7 @@ static void blkdev_bio_end_io(struct bio *bio)
 	if (bio->bi_status && !dio->bio.bi_status)
 		dio->bio.bi_status = bio->bi_status;
 
-	if (!is_sync && (dio->iocb->ki_flags & IOCB_HAS_METADATA))
+	if (bio_integrity(bio))
 		bio_integrity_unmap_user(bio);
 
 	if (atomic_dec_and_test(&dio->ref)) {
@@ -233,7 +233,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
 			}
 			bio->bi_opf |= REQ_NOWAIT;
 		}
-		if (!is_sync && (iocb->ki_flags & IOCB_HAS_METADATA)) {
+		if (iocb->ki_flags & IOCB_HAS_METADATA) {
 			ret = bio_integrity_map_iter(bio, iocb->private);
 			if (unlikely(ret))
 				goto fail;
@@ -301,7 +301,7 @@ static void blkdev_bio_end_io_async(struct bio *bio)
 		ret = blk_status_to_errno(bio->bi_status);
 	}
 
-	if (iocb->ki_flags & IOCB_HAS_METADATA)
+	if (bio_integrity(bio))
 		bio_integrity_unmap_user(bio);
 
 	iocb->ki_complete(iocb, ret);
@@ -422,7 +422,8 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	}
 
 	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
-	if (likely(nr_pages <= BIO_MAX_VECS)) {
+	if (likely(nr_pages <= BIO_MAX_VECS &&
+		   !(iocb->ki_flags & IOCB_HAS_METADATA))) {
 		if (is_sync_kiocb(iocb))
 			return __blkdev_direct_IO_simple(iocb, iter, bdev,
 							nr_pages);
@@ -687,6 +688,8 @@ static int blkdev_open(struct inode *inode, struct file *filp)
 
 	if (bdev_can_atomic_write(bdev))
 		filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
+	if (blk_get_integrity(bdev->bd_disk))
+		filp->f_mode |= FMODE_HAS_METADATA;
 
 	ret = bdev_open(bdev, mode, filp->private_data, NULL, filp);
 	if (ret)

include/linux/fs.h

@@ -149,7 +149,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 /* Expect random access pattern */
 #define FMODE_RANDOM		((__force fmode_t)(1 << 12))
 
-/* FMODE_* bit 13 */
+/* Supports IOCB_HAS_METADATA */
+#define FMODE_HAS_METADATA	((__force fmode_t)(1 << 13))
 
 /* File is opened with O_PATH; almost nothing can be done with it */
 #define FMODE_PATH		((__force fmode_t)(1 << 14))

io_uring/rw.c

@@ -886,6 +886,9 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type)
 	if (req->flags & REQ_F_HAS_METADATA) {
 		struct io_async_rw *io = req->async_data;
 
+		if (!(file->f_mode & FMODE_HAS_METADATA))
+			return -EINVAL;
+
 		/*
 		 * We have a union of meta fields with wpq used for buffered-io
 		 * in io_async_rw, so fail it here.