Merge tag 'vfs-6.13.untorn.writes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs untorn write support from Christian Brauner:
 "An atomic write is a write issed with torn-write protection. This
  means for a power failure or any hardware failure all or none of the
  data from the write will be stored, never a mix of old and new data.

  This work is already supported for block devices. If a block device is
  opened with O_DIRECT and the block device supports atomic write, then
  FMODE_CAN_ATOMIC_WRITE is added to the file of the opened block
  device.

  This contains the work to expand atomic write support to filesystems,
  specifically ext4 and XFS. Currently, only support for writing exactly
  one filesystem block atomically is added.

  Since it's now possible to have filesystem block size > page size for
  XFS, it's possible to write 4K+ blocks atomically on x86"

* tag 'vfs-6.13.untorn.writes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  iomap: drop an obsolete comment in iomap_dio_bio_iter
  ext4: Do not fallback to buffered-io for DIO atomic write
  ext4: Support setting FMODE_CAN_ATOMIC_WRITE
  ext4: Check for atomic writes support in write iter
  ext4: Add statx support for atomic writes
  xfs: Support setting FMODE_CAN_ATOMIC_WRITE
  xfs: Validate atomic writes
  xfs: Support atomic write for statx
  fs: iomap: Atomic write support
  fs: Export generic_atomic_write_valid()
  block: Add bdev atomic write limits helpers
  fs/block: Check for IOCB_DIRECT in generic_atomic_write_valid()
  block/fs: Pass an iocb to generic_atomic_write_valid()

1 files changed, 12 insertions, 10 deletions

diff --git a/block/fops.c b/block/fops.c
index e696ae53bf1e..2d01c9007681 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -35,13 +35,10 @@ static blk_opf_t dio_bio_write_op(struct kiocb *iocb)
 	return opf;
 }
 
-static bool blkdev_dio_invalid(struct block_device *bdev, loff_t pos,
-				struct iov_iter *iter, bool is_atomic)
+static bool blkdev_dio_invalid(struct block_device *bdev, struct kiocb *iocb,
+				struct iov_iter *iter)
 {
-	if (is_atomic && !generic_atomic_write_valid(iter, pos))
-		return true;
-
-	return pos & (bdev_logical_block_size(bdev) - 1) ||
+	return iocb->ki_pos & (bdev_logical_block_size(bdev) - 1) ||
 		!bdev_iter_is_aligned(bdev, iter);
 }
 
@@ -368,13 +365,12 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
 static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 {
 	struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host);
-	bool is_atomic = iocb->ki_flags & IOCB_ATOMIC;
 	unsigned int nr_pages;
 
 	if (!iov_iter_count(iter))
 		return 0;
 
-	if (blkdev_dio_invalid(bdev, iocb->ki_pos, iter, is_atomic))
+	if (blkdev_dio_invalid(bdev, iocb, iter))
 		return -EINVAL;
 
 	nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
@@ -383,7 +379,7 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 			return __blkdev_direct_IO_simple(iocb, iter, bdev,
 							nr_pages);
 		return __blkdev_direct_IO_async(iocb, iter, bdev, nr_pages);
-	} else if (is_atomic) {
+	} else if (iocb->ki_flags & IOCB_ATOMIC) {
 		return -EINVAL;
 	}
 	return __blkdev_direct_IO(iocb, iter, bdev, bio_max_segs(nr_pages));
@@ -625,7 +621,7 @@ static int blkdev_open(struct inode *inode, struct file *filp)
 	if (!bdev)
 		return -ENXIO;
 
-	if (bdev_can_atomic_write(bdev) && filp->f_flags & O_DIRECT)
+	if (bdev_can_atomic_write(bdev))
 		filp->f_mode |= FMODE_CAN_ATOMIC_WRITE;
 
 	ret = bdev_open(bdev, mode, filp->private_data, NULL, filp);
@@ -700,6 +696,12 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
 		return -EOPNOTSUPP;
 
+	if (iocb->ki_flags & IOCB_ATOMIC) {
+		ret = generic_atomic_write_valid(iocb, from);
+		if (ret)
+			return ret;
+	}
+
 	size -= iocb->ki_pos;
 	if (iov_iter_count(from) > size) {
 		shorted = iov_iter_count(from) - size;