[PATCH v16 06/12] fs, block: copy_file_range for def_blk_ops for direct block device

From: Nitesh Shetty
Date: Wed Sep 20 2023 - 04:59:27 EST


For direct block device opened with O_DIRECT, use copy_file_range to
issue device copy offload, or use generic_copy_file_range in case
device copy offload capability is absent or the device files are not open
with O_DIRECT.

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Signed-off-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx>
---
block/fops.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/block/fops.c b/block/fops.c
index acff3d5d22d4..6aa537c0e24f 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -735,6 +735,30 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
return ret;
}

+static ssize_t blkdev_copy_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ size_t len, unsigned int flags)
+{
+ struct block_device *in_bdev = I_BDEV(bdev_file_inode(file_in));
+ struct block_device *out_bdev = I_BDEV(bdev_file_inode(file_out));
+ ssize_t copied = 0;
+
+ if ((in_bdev == out_bdev) && bdev_max_copy_sectors(in_bdev) &&
+ (file_in->f_iocb_flags & IOCB_DIRECT) &&
+ (file_out->f_iocb_flags & IOCB_DIRECT)) {
+ copied = blkdev_copy_offload(in_bdev, pos_in, pos_out, len,
+ NULL, NULL, GFP_KERNEL);
+ if (copied < 0)
+ copied = 0;
+ } else {
+ copied = generic_copy_file_range(file_in, pos_in + copied,
+ file_out, pos_out + copied,
+ len - copied, flags);
+ }
+
+ return copied;
+}
+
#define BLKDEV_FALLOC_FL_SUPPORTED \
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
@@ -828,6 +852,7 @@ const struct file_operations def_blk_fops = {
.splice_read = filemap_splice_read,
.splice_write = iter_file_splice_write,
.fallocate = blkdev_fallocate,
+ .copy_file_range = blkdev_copy_file_range,
};

static __init int blkdev_init(void)
--
2.35.1.500.gb896f729e2