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Commit 685c9b24 authored by Shaun McDowell's avatar Shaun McDowell Committed by Jens Axboe
Browse files

nbd: add FUA op support 



NBD userland client and server have FUA (forced unit access) support
and flags defined. Make NBD kernel module recognize NBD_FLAG_SEND_FUA,
enable FUA on the queue, and forward FUA requests to the server.

Signed-off-by: default avatarShaun McDowell <shaunjmcdowell@gmail.com>
Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 9bddeb2a

drivers/block/nbd.c

+13 −3
Original line number Diff line number Diff line
@@ -400,6 +400,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	unsigned long size = blk_rq_bytes(req);

	struct bio *bio;

	u32 type;

	u32 nbd_cmd_flags = 0;

	u32 tag = blk_mq_unique_tag(req);

	int sent = nsock->sent, skip = 0;
@@ -429,6 +430,9 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
		return -EIO;

	}



	if (req->cmd_flags & REQ_FUA)

		nbd_cmd_flags |= NBD_CMD_FLAG_FUA;



	/* We did a partial send previously, and we at least sent the whole

	 * request struct, so just go and send the rest of the pages in the

	 * request.
@@ -442,7 +446,7 @@ static int nbd_send_cmd(struct nbd_device *nbd, struct nbd_cmd *cmd, int index) 
	}

	cmd->index = index;

	cmd->cookie = nsock->cookie;

	request.type = htonl(type);

	request.type = htonl(type | nbd_cmd_flags);

	if (type != NBD_CMD_FLUSH) {

		request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);

		request.len = htonl(size);
@@ -965,8 +969,12 @@ static void nbd_parse_flags(struct nbd_device *nbd) 
		set_disk_ro(nbd->disk, false);

	if (config->flags & NBD_FLAG_SEND_TRIM)

		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);

	if (config->flags & NBD_FLAG_SEND_FLUSH)

	if (config->flags & NBD_FLAG_SEND_FLUSH) {

		if (config->flags & NBD_FLAG_SEND_FUA)

			blk_queue_write_cache(nbd->disk->queue, true, true);

		else

			blk_queue_write_cache(nbd->disk->queue, true, false);

	}

	else

		blk_queue_write_cache(nbd->disk->queue, false, false);

}
@@ -1309,6 +1317,8 @@ static int nbd_dbg_flags_show(struct seq_file *s, void *unused) 
		seq_puts(s, "NBD_FLAG_READ_ONLY\n");

	if (flags & NBD_FLAG_SEND_FLUSH)

		seq_puts(s, "NBD_FLAG_SEND_FLUSH\n");

	if (flags & NBD_FLAG_SEND_FUA)

		seq_puts(s, "NBD_FLAG_SEND_FUA\n");

	if (flags & NBD_FLAG_SEND_TRIM)

		seq_puts(s, "NBD_FLAG_SEND_TRIM\n");

include/uapi/linux/nbd.h

+4 −0
Original line number Diff line number Diff line
@@ -41,10 +41,14 @@ enum { 
#define NBD_FLAG_HAS_FLAGS	(1 << 0) /* nbd-server supports flags */

#define NBD_FLAG_READ_ONLY	(1 << 1) /* device is read-only */

#define NBD_FLAG_SEND_FLUSH	(1 << 2) /* can flush writeback cache */

#define NBD_FLAG_SEND_FUA	(1 << 3) /* send FUA (forced unit access) */

/* there is a gap here to match userspace */

#define NBD_FLAG_SEND_TRIM	(1 << 5) /* send trim/discard */

#define NBD_FLAG_CAN_MULTI_CONN	(1 << 8)	/* Server supports multiple connections per export. */



/* values for cmd flags in the upper 16 bits of request type */

#define NBD_CMD_FLAG_FUA	(1 << 16) /* FUA (forced unit access) op */



/* These are client behavior specific flags. */

#define NBD_CFLAG_DESTROY_ON_DISCONNECT	(1 << 0) /* delete the nbd device on

						    disconnect. */