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path: root/drivers/block/nbd.c
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Diffstat (limited to 'drivers/block/nbd.c')
-rw-r--r--drivers/block/nbd.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index ade146b..695c68f 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -98,6 +98,7 @@ static const char *nbdcmd_to_ascii(int cmd)
case NBD_CMD_READ: return "read";
case NBD_CMD_WRITE: return "write";
case NBD_CMD_DISC: return "disconnect";
+ case NBD_CMD_FLUSH: return "flush";
case NBD_CMD_TRIM: return "trim/discard";
}
return "invalid";
@@ -244,8 +245,15 @@ static int nbd_send_req(struct nbd_device *nbd, struct request *req)
request.magic = htonl(NBD_REQUEST_MAGIC);
request.type = htonl(nbd_cmd(req));
- request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
- request.len = htonl(size);
+
+ if (nbd_cmd(req) == NBD_CMD_FLUSH) {
+ /* Other values are reserved for FLUSH requests. */
+ request.from = 0;
+ request.len = 0;
+ } else {
+ request.from = cpu_to_be64((u64)blk_rq_pos(req) << 9);
+ request.len = htonl(size);
+ }
memcpy(request.handle, &req, sizeof(req));
dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%uB)\n",
@@ -482,6 +490,11 @@ static void nbd_handle_req(struct nbd_device *nbd, struct request *req)
}
}
+ if (req->cmd_flags & REQ_FLUSH) {
+ BUG_ON(unlikely(blk_rq_sectors(req)));
+ nbd_cmd(req) = NBD_CMD_FLUSH;
+ }
+
req->errors = 0;
mutex_lock(&nbd->tx_lock);
@@ -684,6 +697,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
if (nbd->flags & NBD_FLAG_SEND_TRIM)
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
nbd->disk->queue);
+ if (nbd->flags & NBD_FLAG_SEND_FLUSH)
+ blk_queue_flush(nbd->disk->queue, REQ_FLUSH);
+ else
+ blk_queue_flush(nbd->disk->queue, 0);
thread = kthread_create(nbd_thread, nbd, nbd->disk->disk_name);
if (IS_ERR(thread)) {
@@ -705,6 +722,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
if (file)
fput(file);
+ nbd->flags = 0;
nbd->bytesize = 0;
bdev->bd_inode->i_size = 0;
set_capacity(nbd->disk, 0);