[PATCH v6 21/25] rnbd: server: functionality for IO submission to file or block dev

Jack Wang
2019-12-30T10:30:14Z

From: Jack Wang <jinpu.wang@cloud.ionos.com>

This provides helper functions for IO submission to file or block dev.

Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
drivers/block/rnbd/rnbd-srv-dev.c | 144 ++++++++++++++++++++++++++++++
drivers/block/rnbd/rnbd-srv-dev.h | 112 +++++++++++++++++++++++
2 files changed, 256 insertions(+)
create mode 100644 drivers/block/rnbd/rnbd-srv-dev.c
create mode 100644 drivers/block/rnbd/rnbd-srv-dev.h

diff --git a/drivers/block/rnbd/rnbd-srv-dev.c b/drivers/block/rnbd/rnbd-srv-dev.c
new file mode 100644
index 000000000000..49305e0b2d40
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-dev.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * InfiniBand Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ *
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ *
+ * Copyright (c) 2019 1&1 IONOS SE. All rights reserved.
+ */
+#undef pr_fmt
+#define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
+
+#include "rnbd-srv-dev.h"
+#include "rnbd-log.h"
+
+struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags,
+ struct bio_set *bs, rnbd_dev_io_fn io_cb)
+{
+ struct rnbd_dev *dev;
+ int ret;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ dev->blk_open_flags = flags;
+ dev->bdev = blkdev_get_by_path(path, flags, THIS_MODULE);
+ ret = PTR_ERR_OR_ZERO(dev->bdev);
+ if (ret)
+ goto err;
+
+ dev->blk_open_flags = flags;
+ dev->io_cb = io_cb;
+ bdevname(dev->bdev, dev->name);
+ dev->ibd_bio_set = bs;
+
+ return dev;
+
+err:
+ kfree(dev);
+ return ERR_PTR(ret);
+}
+
+void rnbd_dev_close(struct rnbd_dev *dev)
+{
+ blkdev_put(dev->bdev, dev->blk_open_flags);
+ kfree(dev);
+}
+
+static void rnbd_dev_bi_end_io(struct bio *bio)
+{
+ struct rnbd_dev_blk_io *io = bio->bi_private;
+
+ io->dev->io_cb(io->priv, blk_status_to_errno(bio->bi_status));
+ bio_put(bio);
+}
+
+/**
+ * rnbd_bio_map_kern - map kernel address into bio
+ * @q: the struct request_queue for the bio
+ * @data: pointer to buffer to map
+ * @bs: bio_set to use.
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio allocation
+ *
+ * Map the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+static struct bio *rnbd_bio_map_kern(struct request_queue *q, void *data,
+ struct bio_set *bs,
+ unsigned int len, gfp_t gfp_mask)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ const int nr_pages = end - start;
+ int offset, i;
+ struct bio *bio;
+
+ bio = bio_alloc_bioset(gfp_mask, nr_pages, bs);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ offset = offset_in_page(kaddr);
+ for (i = 0; i < nr_pages; i++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
+ offset) < bytes) {
+ /* we don't support partial mappings */
+ bio_put(bio);
+ return ERR_PTR(-EINVAL);
+ }
+
+ data += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ bio->bi_end_io = bio_put;
+ return bio;
+}
+
+int rnbd_dev_submit_io(struct rnbd_dev *dev, sector_t sector, void *data,
+ size_t len, u32 bi_size, enum rnbd_io_flags flags,
+ short prio, void *priv)
+{
+ struct request_queue *q = bdev_get_queue(dev->bdev);
+ struct rnbd_dev_blk_io *io;
+ struct bio *bio;
+
+ /* check if the buffer is suitable for bdev */
+ if (WARN_ON(!blk_rq_aligned(q, (unsigned long)data, len)))
+ return -EINVAL;
+
+ /* Generate bio with pages pointing to the rdma buffer */
+ bio = rnbd_bio_map_kern(q, data, dev->ibd_bio_set, len, GFP_KERNEL);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ io = container_of(bio, struct rnbd_dev_blk_io, bio);
+
+ io->dev = dev;
+ io->priv = priv;
+
+ bio->bi_end_io = rnbd_dev_bi_end_io;
+ bio->bi_private = io;
+ bio->bi_opf = rnbd_to_bio_flags(flags);
+ bio->bi_iter.bi_sector = sector;
+ bio->bi_iter.bi_size = bi_size;
+ bio_set_prio(bio, prio);
+ bio_set_dev(bio, dev->bdev);
+
+ submit_bio(bio);
+
+ return 0;
+}
diff --git a/drivers/block/rnbd/rnbd-srv-dev.h b/drivers/block/rnbd/rnbd-srv-dev.h
new file mode 100644
index 000000000000..f2b5f8d56383
--- /dev/null
+++ b/drivers/block/rnbd/rnbd-srv-dev.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * InfiniBand Network Block Driver
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ *
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ *
+ * Copyright (c) 2019 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RNBD_SRV_DEV_H
+#define RNBD_SRV_DEV_H
+
+#include <linux/fs.h>
+#include "rnbd-proto.h"
+
+typedef void rnbd_dev_io_fn(void *priv, int error);
+
+struct rnbd_dev {
+ struct block_device *bdev;
+ struct bio_set *ibd_bio_set;
+ fmode_t blk_open_flags;
+ char name[BDEVNAME_SIZE];
+ rnbd_dev_io_fn *io_cb;
+};
+
+struct rnbd_dev_blk_io {
+ struct rnbd_dev *dev;
+ void *priv;
+ /* have to be last member for front_pad usage of bioset_init */
+ struct bio bio;
+};
+
+/**
+ * rnbd_dev_open() - Open a device
+ * @flags: open flags
+ * @bs: bio_set to use during block io,
+ * @io_cb: is called when I/O finished
+ */
+struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags,
+ struct bio_set *bs, rnbd_dev_io_fn io_cb);
+
+/**
+ * rnbd_dev_close() - Close a device
+ */
+void rnbd_dev_close(struct rnbd_dev *dev);
+
+static inline int rnbd_dev_get_logical_bsize(const struct rnbd_dev *dev)
+{
+ return bdev_logical_block_size(dev->bdev);
+}
+
+static inline int rnbd_dev_get_phys_bsize(const struct rnbd_dev *dev)
+{
+ return bdev_physical_block_size(dev->bdev);
+}
+
+static inline int rnbd_dev_get_max_segs(const struct rnbd_dev *dev)
+{
+ return queue_max_segments(bdev_get_queue(dev->bdev));
+}
+
+static inline int rnbd_dev_get_max_hw_sects(const struct rnbd_dev *dev)
+{
+ return queue_max_hw_sectors(bdev_get_queue(dev->bdev));
+}
+
+static inline int
+rnbd_dev_get_max_write_same_sects(const struct rnbd_dev *dev)
+{
+ return bdev_write_same(dev->bdev);
+}
+
+static inline int rnbd_dev_get_secure_discard(const struct rnbd_dev *dev)
+{
+ return blk_queue_secure_erase(bdev_get_queue(dev->bdev));
+}
+
+static inline int rnbd_dev_get_max_discard_sects(const struct rnbd_dev *dev)
+{
+ if (!blk_queue_discard(bdev_get_queue(dev->bdev)))
+ return 0;
+
+ return blk_queue_get_max_sectors(bdev_get_queue(dev->bdev),
+ REQ_OP_DISCARD);
+}
+
+static inline int rnbd_dev_get_discard_granularity(const struct rnbd_dev *dev)
+{
+ return bdev_get_queue(dev->bdev)->limits.discard_granularity;
+}
+
+static inline int rnbd_dev_get_discard_alignment(const struct rnbd_dev *dev)
+{
+ return bdev_get_queue(dev->bdev)->limits.discard_alignment;
+}
+
+/**
+ * rnbd_dev_submit_io() - Submit an I/O to the disk
+ * @dev: device to that the I/O is submitted
+ * @sector: address to read/write data to
+ * @data: I/O data to write or buffer to read I/O date into
+ * @len: length of @data
+ * @bi_size: Amount of data that will be read/written
+ * @prio: IO priority
+ * @priv: private data passed to @io_fn
+ */
+int rnbd_dev_submit_io(struct rnbd_dev *dev, sector_t sector, void *data,
+ size_t len, u32 bi_size, enum rnbd_io_flags flags,
+ short prio, void *priv);
+
+#endif /* RNBD_SRV_DEV_H */
--
2.17.1