Commit a30b59fa authored by Jim Harris's avatar Jim Harris
Browse files

aio: create blockdev_aio_io_channel abstraction 



This breaks out the resources needed to perform
aio-based I/O into a separate data structure, as a steps
towards some future patches that will enable per-thread
resources to enable parallel I/O without synchronization.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: I84b95713133f9c411863ff0aeef8f886a08e0857
parent d85dce3b

lib/bdev/aio/blockdev_aio.c

+39 −21
Original line number Diff line number Diff line
@@ -81,7 +81,7 @@ blockdev_aio_close(struct file_disk *disk) 
{

	int rc;



	io_destroy(disk->io_ctx);

	io_destroy(disk->ch.io_ctx);



	if (disk->fd == -1) {

		return 0;
@@ -117,7 +117,7 @@ blockdev_aio_read(struct file_disk *fdisk, struct blockdev_aio_task *aio_task, 
	SPDK_TRACELOG(SPDK_TRACE_AIO, "read from %p of size %lu to off: %#lx\n",

		      buf, nbytes, offset);



	rc = io_submit(fdisk->io_ctx, 1, &iocb);

	rc = io_submit(fdisk->ch.io_ctx, 1, &iocb);

	if (rc < 0) {

		SPDK_ERRLOG("%s: io_submit returned %d\n", __func__, rc);

		return -1;
@@ -145,7 +145,7 @@ blockdev_aio_writev(struct file_disk *fdisk, struct blockdev_aio_task *aio_task, 
	SPDK_TRACELOG(SPDK_TRACE_AIO, "write %d iovs size %lu from off: %#lx\n",

		      iovcnt, len, offset);



	rc = io_submit(fdisk->io_ctx, 1, &iocb);

	rc = io_submit(fdisk->ch.io_ctx, 1, &iocb);

	if (rc < 0) {

		SPDK_ERRLOG("%s: io_submit returned %d\n", __func__, rc);

		return -1;
@@ -181,28 +181,47 @@ blockdev_aio_destruct(struct spdk_bdev *bdev) 
}



static int

blockdev_aio_check_io(struct spdk_bdev *bdev)

blockdev_aio_initialize_io_channel(struct blockdev_aio_io_channel *ch)

{

	ch->queue_depth = 128;



	if (io_setup(ch->queue_depth, &ch->io_ctx) < 0) {

		SPDK_ERRLOG("async I/O context setup failure\n");

		return -1;

	}



	ch->events = calloc(sizeof(struct io_event), ch->queue_depth);

	if (!ch->events) {

		io_destroy(ch->io_ctx);

		return -1;

	}



	return 0;

}



static void

blockdev_aio_poll(void *arg)

{

	struct blockdev_aio_io_channel *ch = arg;

	int nr, i;

	enum spdk_bdev_io_status status;

	struct blockdev_aio_task *aio_task;

	struct file_disk *fdisk = (struct file_disk *)bdev;

	struct timespec timeout;



	timeout.tv_sec = 0;

	timeout.tv_nsec = 0;



	nr = io_getevents(fdisk->io_ctx, 1, fdisk->queue_depth,

			  fdisk->events, &timeout);

	nr = io_getevents(ch->io_ctx, 1, ch->queue_depth,

			  ch->events, &timeout);



	if (nr < 0) {

		SPDK_ERRLOG("%s: io_getevents returned %d\n", __func__, nr);

		return -1;

		return;

	}



	for (i = 0; i < nr; i++) {

		aio_task = fdisk->events[i].data;

		if (fdisk->events[i].res != aio_task->len) {

		aio_task = ch->events[i].data;

		if (ch->events[i].res != aio_task->len) {

			status = SPDK_BDEV_IO_STATUS_FAILED;

		} else {

			status = SPDK_BDEV_IO_STATUS_SUCCESS;
@@ -210,7 +229,14 @@ blockdev_aio_check_io(struct spdk_bdev *bdev) 


		spdk_bdev_io_complete(spdk_bdev_io_from_ctx(aio_task), status);

	}

}



static int

blockdev_aio_check_io(struct spdk_bdev *bdev)

{

	struct file_disk *fdisk = (struct file_disk *)bdev;



	blockdev_aio_poll(&fdisk->ch);

	return 0;

}
@@ -299,8 +325,8 @@ static void aio_free_disk(struct file_disk *fdisk) 
{

	if (fdisk == NULL)

		return;

	if (fdisk->events != NULL)

		free(fdisk->events);

	if (fdisk->ch.events != NULL)

		free(fdisk->ch.events);

	free(fdisk);

}
@@ -322,7 +348,6 @@ create_aio_disk(char *fname) 
	}



	fdisk->size = spdk_fd_get_size(fdisk->fd);

	fdisk->queue_depth = 128; // TODO: where do we get the queue depth from.



	TAILQ_INIT(&fdisk->sync_completion_list);

	snprintf(fdisk->disk.name, SPDK_BDEV_MAX_NAME_LENGTH, "AIO%d",
@@ -336,14 +361,7 @@ create_aio_disk(char *fname) 
	fdisk->disk.ctxt = fdisk;



	fdisk->disk.fn_table = &aio_fn_table;

	if (io_setup(fdisk->queue_depth, &fdisk->io_ctx) < 0) {

		SPDK_ERRLOG("async I/O context setup failure\n");

		goto error_return;

	}



	fdisk->events = calloc(sizeof(struct io_event), fdisk->queue_depth);

	if (!fdisk->events) {

		SPDK_ERRLOG("unable to allocate async events\n");

	if (blockdev_aio_initialize_io_channel(&fdisk->ch) != 0) {

		goto error_return;

	}

lib/bdev/aio/blockdev_aio.h

+8 −5
Original line number Diff line number Diff line
@@ -48,23 +48,26 @@ struct blockdev_aio_task { 
	TAILQ_ENTRY(blockdev_aio_task)	link;

};



struct blockdev_aio_io_channel {

	io_context_t		io_ctx;

	long			queue_depth;

	struct io_event		*events;

};



struct file_disk {

	struct spdk_bdev	disk;	/* this must be first element */

	char			*file;

	int			fd;

	char			disk_name[SPDK_BDEV_MAX_NAME_LENGTH];

	long			queue_depth;

	uint64_t		size;



	struct blockdev_aio_io_channel	ch;



	/**

	 * For storing I/O that were completed synchronously, and will be

	 *   completed during next check_io call.

	 */

	TAILQ_HEAD(, blockdev_aio_task) sync_completion_list;



	/* for libaio */

	io_context_t io_ctx;

	struct io_event *events;

};



struct file_disk *create_aio_disk(char *fname);