From 685c9b24ad5090e7a74781c4784fc12e0a04a176 Mon Sep 17 00:00:00 2001 From: Shaun McDowell Date: Thu, 25 May 2017 23:55:54 -0400 Subject: [PATCH] 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: Shaun McDowell Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe --- drivers/block/nbd.c | 16 +++++++++++++--- include/uapi/linux/nbd.h | 4 ++++ 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 9a7bb2c29447..c5e52f66d3d4 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -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) - blk_queue_write_cache(nbd->disk->queue, true, false); + 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"); diff --git a/include/uapi/linux/nbd.h b/include/uapi/linux/nbd.h index 155e33f81913..a50527ebf671 100644 --- a/include/uapi/linux/nbd.h +++ b/include/uapi/linux/nbd.h @@ -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. */ -- 2.30.2