OSDN Git Service

block/rnbd: server: functionality for IO submitting to block dev
authorJack Wang <jinpu.wang@cloud.ionos.com>
Mon, 11 May 2020 13:51:27 +0000 (15:51 +0200)
committerJason Gunthorpe <jgg@mellanox.com>
Sun, 17 May 2020 21:57:17 +0000 (18:57 -0300)
This provides helper functions for IO submitting to block dev.

Link: https://lore.kernel.org/r/20200511135131.27580-22-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
drivers/block/rnbd/rnbd-srv-dev.c [new file with mode: 0644]
drivers/block/rnbd/rnbd-srv-dev.h [new file with mode: 0644]

diff --git a/drivers/block/rnbd/rnbd-srv-dev.c b/drivers/block/rnbd/rnbd-srv-dev.c
new file mode 100644 (file)
index 0000000..5eddfd2
--- /dev/null
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * RDMA 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 - 2020 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)
+{
+       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;
+       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;
+
+       rnbd_endio(io->priv, blk_status_to_errno(bio->bi_status));
+       bio_put(bio);
+}
+
+/**
+ *     rnbd_bio_map_kern       -       map kernel address into 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(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_page(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 rnbd_dev_blk_io *io;
+       struct bio *bio;
+
+       /* Generate bio with pages pointing to the rdma buffer */
+       bio = rnbd_bio_map_kern(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 (file)
index 0000000..0f65b09
--- /dev/null
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA 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 - 2020 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"
+
+struct rnbd_dev {
+       struct block_device     *bdev;
+       struct bio_set          *ibd_bio_set;
+       fmode_t                 blk_open_flags;
+       char                    name[BDEVNAME_SIZE];
+};
+
+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,
+ */
+struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags,
+                              struct bio_set *bs);
+
+/**
+ * rnbd_dev_close() - Close a device
+ */
+void rnbd_dev_close(struct rnbd_dev *dev);
+
+void rnbd_endio(void *priv, int error);
+
+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_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 */