From d970958b2d24e9a40b685ad82bf26a291d6f1c25 Mon Sep 17 00:00:00 2001 From: Hou Pu Date: Fri, 28 Feb 2020 01:40:29 -0500 Subject: [PATCH] nbd: enable replace socket if only one connection is configured Nbd server with multiple connections could be upgraded since 560bc4b (nbd: handle dead connections). But if only one conncection is configured, after we take down nbd server, all inflight IO would finally timeout and return error. We could requeue them like what we do with multiple connections and wait for new socket in submit path. Reviewed-by: Josef Bacik Signed-off-by: Hou Pu Signed-off-by: Jens Axboe --- drivers/block/nbd.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 78181908f0df..83070714888b 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -395,16 +395,19 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, } config = nbd->config; - if (config->num_connections > 1) { + if (config->num_connections > 1 || + (config->num_connections == 1 && nbd->tag_set.timeout)) { dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out, retrying (%d/%d alive)\n", atomic_read(&config->live_connections), config->num_connections); /* * Hooray we have more connections, requeue this IO, the submit - * path will put it on a real connection. + * path will put it on a real connection. Or if only one + * connection is configured, the submit path will wait util + * a new connection is reconfigured or util dead timeout. */ - if (config->socks && config->num_connections > 1) { + if (config->socks) { if (cmd->index < config->num_connections) { struct nbd_sock *nsock = config->socks[cmd->index]; @@ -741,14 +744,12 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) dev_err(disk_to_dev(nbd->disk), "Receive data failed (result %d)\n", result); /* - * If we've disconnected or we only have 1 - * connection then we need to make sure we + * If we've disconnected, we need to make sure we * complete this request, otherwise error out * and let the timeout stuff handle resubmitting * this request onto another connection. */ - if (nbd_disconnected(config) || - config->num_connections <= 1) { + if (nbd_disconnected(config)) { cmd->status = BLK_STS_IOERR; goto out; } @@ -825,7 +826,7 @@ static int find_fallback(struct nbd_device *nbd, int index) if (config->num_connections <= 1) { dev_err_ratelimited(disk_to_dev(nbd->disk), - "Attempted send on invalid socket\n"); + "Dead connection, failed to find a fallback\n"); return new_index; }