Commit 670dc20f authored by Seth Howell's avatar Seth Howell Committed by Daniel Verkamp
Browse files

bdev: add write_zeroes function 



Add functionality to the bdev layer to handle the nvme write_zeroes
function.

Change-Id: I0dadad273b28c16db5a2275f7d8d57e98253a8d3
Signed-off-by: default avatarSeth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/372171


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
parent 0720ad35

CHANGELOG.md

+6 −0
Original line number Diff line number Diff line
@@ -6,10 +6,16 @@ An [fio](http://github.com/axboe/fio) plugin was added that can route 
I/O to the bdev layer. See the [plugin documentation](https://github.com/spdk/spdk/blob/master/examples/bdev/fio_plugin/README.md)

for more information.



### Block Device Abstraction Layer (bdev)



spdk_bdev_unmap() was modified to take an offset and a length in bytes as

arguments instead of requiring the user to provide an array of SCSI

unmap descriptors. This limits unmaps to a single contiguous range.



spdk_bdev_write_zeroes() was introduced as an alternative to spdk_bdev_unmap().

It ensures that all unmapped blocks will be zeroed out. This function is

currently only supported by NVMe block devices.



### Linux AIO bdev



The AIO bdev now allows the user to override the auto-detected block size.

include/spdk/bdev.h

+20 −0
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ enum spdk_bdev_io_type { 
	SPDK_BDEV_IO_TYPE_RESET,

	SPDK_BDEV_IO_TYPE_NVME_ADMIN,

	SPDK_BDEV_IO_TYPE_NVME_IO,

	SPDK_BDEV_IO_TYPE_WRITE_ZEROES,

};



/**
@@ -329,6 +330,25 @@ int spdk_bdev_writev(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch, 
		     uint64_t offset, uint64_t len,

		     spdk_bdev_io_completion_cb cb, void *cb_arg);



/**

 * Submit a write zeroes request to the bdev on the given channel. This command

 *  ensures that all bytes in the specified range are set to 00h

 *

 * \param bdev Block device

 * \param ch I/O channel. Obtained by calling spdk_bdev_get_io_channel().

 * \param offset The offset, in bytes, from the start of the block device.

 * \param nbytes The number of bytes to zero.

 * \param cb Called when the request is complete.

 * \param cb_arg Argument passed to cb.

 *

 * \return 0 on success. On success, the callback will always

 * be called (even if the request ultimately failed). Return

 * negated errno on failure, in which case the callback will not be called.

 */

int spdk_bdev_write_zeroes(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch,

			   uint64_t offset, uint64_t len,

			   spdk_bdev_io_completion_cb cb, void *cb_arg);



/**

 * Submit an unmap request to the block device. Unmap is sometimes also called trim or

 * deallocate. This notifies the device that the data in the blocks described is no

lib/bdev/bdev.c

+36 −0
Original line number Diff line number Diff line
@@ -928,6 +928,42 @@ spdk_bdev_writev(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch, 
	return 0;

}



int

spdk_bdev_write_zeroes(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch,

		       uint64_t offset, uint64_t len,

		       spdk_bdev_io_completion_cb cb, void *cb_arg)

{

	int rc;

	struct spdk_bdev *bdev = desc->bdev;

	struct spdk_bdev_io *bdev_io;

	struct spdk_bdev_channel *channel = spdk_io_channel_get_ctx(ch);



	if (!spdk_bdev_io_valid(bdev, offset, len)) {

		return -EINVAL;

	}



	bdev_io = spdk_bdev_get_io();

	if (!bdev_io) {

		SPDK_ERRLOG("bdev_io memory allocation failed duing write_zeroes\n");

		return -ENOMEM;

	}



	bdev_io->ch = channel;

	bdev_io->u.write.len = len;

	bdev_io->u.write.offset = offset;

	bdev_io->type = SPDK_BDEV_IO_TYPE_WRITE_ZEROES;



	spdk_bdev_io_init(bdev_io, bdev, cb_arg, cb);



	rc = spdk_bdev_io_submit(bdev_io);

	if (rc < 0) {

		spdk_bdev_put_io(bdev_io);

		return rc;

	}



	return 0;

}



int

spdk_bdev_unmap(struct spdk_bdev_desc *desc, struct spdk_io_channel *ch,

		uint64_t offset, uint64_t nbytes,

lib/bdev/rpc/bdev_rpc.c

+2 −0
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ spdk_rpc_get_bdevs(struct spdk_jsonrpc_request *request, 
		spdk_json_write_bool(w, spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE));

		spdk_json_write_name(w, "unmap");

		spdk_json_write_bool(w, spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_UNMAP));

		spdk_json_write_name(w, "write_zeroes");

		spdk_json_write_bool(w, spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_WRITE_ZEROES));

		spdk_json_write_name(w, "flush");

		spdk_json_write_bool(w, spdk_bdev_io_type_supported(bdev, SPDK_BDEV_IO_TYPE_FLUSH));

		spdk_json_write_name(w, "reset");