[PATCH 11/15] iomap: use a function pointer for dio submits

Goldwyn Rodrigues
2019-09-05T15:07:24Z

This helps filesystems to perform tasks on the bio while
submitting for I/O. This could be post-write operations
such as data CRC or data replication for fs-handled RAID.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
fs/iomap/direct-io.c | 16 +++++++++++-----
include/linux/iomap.h | 2 ++
2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index e3ccbf7daaae..2923b02c1d57 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -59,7 +59,7 @@ int iomap_dio_iopoll(struct kiocb *kiocb, bool spin)
EXPORT_SYMBOL_GPL(iomap_dio_iopoll);

static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap,
- struct bio *bio)
+ struct bio *bio, loff_t pos)
{
atomic_inc(&dio->ref);

@@ -67,7 +67,13 @@ static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap,
bio_set_polled(bio, dio->iocb);

dio->submit.last_queue = bdev_get_queue(iomap->bdev);
- dio->submit.cookie = submit_bio(bio);
+ if (dio->dops && dio->dops->submit_io) {
+ dio->dops->submit_io(bio, file_inode(dio->iocb->ki_filp),
+ pos);
+ dio->submit.cookie = BLK_QC_T_NONE;
+ } else {
+ dio->submit.cookie = submit_bio(bio);
+ }
}

static ssize_t iomap_dio_complete(struct iomap_dio *dio)
@@ -191,7 +197,7 @@ iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos,
get_page(page);
__bio_add_page(bio, page, len, 0);
bio_set_op_attrs(bio, REQ_OP_WRITE, flags);
- iomap_dio_submit_bio(dio, iomap, bio);
+ iomap_dio_submit_bio(dio, iomap, bio, pos);
}

static loff_t
@@ -297,11 +303,11 @@ iomap_dio_bio_actor(struct inode *inode, loff_t pos, loff_t length,
iov_iter_advance(dio->submit.iter, n);

dio->size += n;
- pos += n;
copied += n;

nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES);
- iomap_dio_submit_bio(dio, iomap, bio);
+ iomap_dio_submit_bio(dio, iomap, bio, pos);
+ pos += n;
} while (nr_pages);

/*
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 7fdb09925740..1bcb2f14bd9a 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -196,6 +196,8 @@ sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
struct iomap_dio_ops {
int (*end_io)(struct kiocb *iocb, ssize_t size, int error,
unsigned flags);
+ void (*submit_io)(struct bio *bio, struct inode *inode,
+ loff_t file_offset);
};

ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
--
2.16.4