[PATCH v13 4/9] fs, block: copy_file_range for def_blk_ops for direct block device

Nitesh Shetty
2023-06-28T08:25:56Z

For direct block device opened with O_DIRECT, use copy_file_range to
issue device copy offload, and fallback to generic_copy_file_range incase
device copy offload capability is absent.
Modify checks to allow bdevs to use copy_file_range.

Suggested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
---
block/blk-lib.c | 26 ++++++++++++++++++++++++++
block/fops.c | 20 ++++++++++++++++++++
fs/read_write.c | 7 +++++--
include/linux/blkdev.h | 4 ++++
4 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 09e0d5d51d03..7d8e09a99254 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -473,6 +473,32 @@ ssize_t blkdev_copy_offload(
}
EXPORT_SYMBOL_GPL(blkdev_copy_offload);

+/* Copy source offset from source block device to destination block
+ * device. Returns the length of bytes copied.
+ */
+ssize_t blkdev_copy_offload_failfast(
+ struct block_device *bdev_in, loff_t pos_in,
+ struct block_device *bdev_out, loff_t pos_out,
+ size_t len, gfp_t gfp_mask)
+{
+ struct request_queue *in_q = bdev_get_queue(bdev_in);
+ struct request_queue *out_q = bdev_get_queue(bdev_out);
+ ssize_t ret = 0;
+
+ if (blkdev_copy_sanity_check(bdev_in, pos_in, bdev_out, pos_out, len))
+ return 0;
+
+ if (blk_queue_copy(in_q) && blk_queue_copy(out_q)) {
+ ret = __blkdev_copy_offload(bdev_in, pos_in, bdev_out, pos_out,
+ len, NULL, NULL, gfp_mask);
+ if (ret < 0)
+ return 0;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_copy_offload_failfast);
+
static int __blkdev_issue_write_zeroes(struct block_device *bdev,
sector_t sector, sector_t nr_sects, gfp_t gfp_mask,
struct bio **biop, unsigned flags)
diff --git a/block/fops.c b/block/fops.c
index a286bf3325c5..a1576304f269 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -621,6 +621,25 @@ 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 comp_len = 0;
+
+ if ((file_in->f_iocb_flags & IOCB_DIRECT) &&
+ (file_out->f_iocb_flags & IOCB_DIRECT))
+ comp_len = blkdev_copy_offload_failfast(in_bdev, pos_in,
+ out_bdev, pos_out, len, GFP_KERNEL);
+ if (comp_len != len)
+ comp_len = generic_copy_file_range(file_in, pos_in + comp_len,
+ file_out, pos_out + comp_len, len - comp_len, flags);
+
+ return comp_len;
+}
+
#define BLKDEV_FALLOC_FL_SUPPORTED \
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
@@ -714,6 +733,7 @@ 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)
diff --git a/fs/read_write.c b/fs/read_write.c
index b07de77ef126..d27148a2543f 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1447,7 +1447,8 @@ static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
return -EOVERFLOW;

/* Shorten the copy to EOF */
- size_in = i_size_read(inode_in);
+ size_in = i_size_read(file_in->f_mapping->host);
+
if (pos_in >= size_in)
count = 0;
else
@@ -1708,7 +1709,9 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out)
/* Don't copy dirs, pipes, sockets... */
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
return -EISDIR;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+
+ if ((!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) &&
+ (!S_ISBLK(inode_in->i_mode) || !S_ISBLK(inode_out->i_mode)))
return -EINVAL;

if (!(file_in->f_mode & FMODE_READ) ||
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c176bf6173c5..850168cad080 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1047,6 +1047,10 @@ ssize_t blkdev_copy_offload(
struct block_device *bdev_in, loff_t pos_in,
struct block_device *bdev_out, loff_t pos_out,
size_t len, cio_iodone_t end_io, void *private, gfp_t gfp_mask);
+ssize_t blkdev_copy_offload_failfast(
+ struct block_device *bdev_in, loff_t pos_in,
+ struct block_device *bdev_out, loff_t pos_out,
+ size_t len, gfp_t gfp_mask);
struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
gfp_t gfp_mask);
void bio_map_kern_endio(struct bio *bio);
--
2.35.1.500.gb896f729e2