diff options
| author |   Kevin Vigor <kvigor@fb.com> | 2018-05-30 10:45:11 -0600 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2018-05-30 11:30:42 -0600 |
| commit | 5e3c3a7ecefefaebc7c9a626fe4522cb85bbdaad (patch) | |
| tree | 03f7f01f6c8164298296f87344a71dd754fab70b /drivers/block/nbd.c | |
| parent | blk-throttle: fix potential NULL pointer dereference in throtl_select_dispatch (diff) | |
| download | linux-dev-5e3c3a7ecefefaebc7c9a626fe4522cb85bbdaad.tar.xz linux-dev-5e3c3a7ecefefaebc7c9a626fe4522cb85bbdaad.zip | |
nbd: clear DISCONNECT_REQUESTED flag once disconnection occurs.
When a userspace client requests a NBD device be disconnected, the
DISCONNECT_REQUESTED flag is set. While this flag is set, the driver
will not inform userspace when a connection is closed.
Unfortunately the flag was never cleared, so once a disconnect was
requested the driver would thereafter never tell userspace about a
closed connection. Thus when connections failed due to timeout, no
attempt to reconnect was made and eventually the device would fail.
Fix by clearing the DISCONNECT_REQUESTED flag (and setting the
DISCONNECTED flag) once all connections are closed.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Kevin Vigor <kvigor@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/nbd.c')
| -rw-r--r-- | drivers/block/nbd.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 8860b24098bc..a6e3a6f05791 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -216,7 +216,15 @@ static void nbd_mark_nsock_dead(struct nbd_device *nbd, struct nbd_sock *nsock, } if (!nsock->dead) { kernel_sock_shutdown(nsock->sock, SHUT_RDWR); - atomic_dec(&nbd->config->live_connections); + if (atomic_dec_return(&nbd->config->live_connections) == 0) { + if (test_and_clear_bit(NBD_DISCONNECT_REQUESTED, + &nbd->config->runtime_flags)) { + set_bit(NBD_DISCONNECTED, + &nbd->config->runtime_flags); + dev_info(nbd_to_dev(nbd), + "Disconnected due to user request.\n"); + } + } } nsock->dead = true; nsock->pending = NULL; @@ -310,7 +318,9 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, if (config->num_connections > 1) { dev_err_ratelimited(nbd_to_dev(nbd), - "Connection timed out, retrying\n"); + "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. @@ -733,10 +743,9 @@ static int wait_for_reconnect(struct nbd_device *nbd) return 0; if (test_bit(NBD_DISCONNECTED, &config->runtime_flags)) return 0; - wait_event_timeout(config->conn_wait, - atomic_read(&config->live_connections), - config->dead_conn_timeout); - return atomic_read(&config->live_connections); + return wait_event_timeout(config->conn_wait, + atomic_read(&config->live_connections) > 0, + config->dead_conn_timeout) > 0; } static int nbd_handle_cmd(struct nbd_cmd *cmd, int index) |