kernel.git/net/sunrpc, branch linux-5.16.y

SUNRPC: Ensure we flush any closed sockets before xs_xprt_free()

2022-04-13T18:03:23Z

commit f00432063db1a0db484e85193eccc6845435b80e upstream. We must ensure that all sockets are closed before we call xprt_free() and release the reference to the net namespace. The problem is that calling fput() will defer closing the socket until delayed_fput() gets called. Let's fix the situation by allowing rpciod and the transport teardown code (which runs on the system wq) to call __fput_sync(), and directly close the socket. Reported-by: Felix Fu Acked-by: Al Viro Fixes: a73881c96d73 ("SUNRPC: Fix an Oops in udp_poll()") Cc: stable@vger.kernel.org # 5.1.x: 3be232f11a3c: SUNRPC: Prevent immediate close+reconnect Cc: stable@vger.kernel.org # 5.1.x: 89f42494f92f: SUNRPC: Don't call connect() more than once on a TCP socket Cc: stable@vger.kernel.org # 5.1.x Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

SUNRPC: svc_tcp_sendmsg() should handle errors from xdr_alloc_bvec()

2022-04-13T18:03:18Z

[ Upstream commit b056fa070814897be32d83b079dbc311375588e7 ] The allocation is done with GFP_KERNEL, but it could still fail in a low memory situation. Fixes: 4a85a6a3320b ("SUNRPC: Handle TCP socket sends with kernel_sendpage() again") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: Handle low memory situations in call_status()

2022-04-13T18:03:18Z

[ Upstream commit 9d82819d5b065348ce623f196bf601028e22ed00 ] We need to handle ENFILE, ENOBUFS, and ENOMEM, because xprt_wake_pending_tasks() can be called with any one of these due to socket creation failures. Fixes: b61d59fffd3e ("SUNRPC: xs_tcp_connect_worker{4,6}: merge common code") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: Handle ENOMEM in call_transmit_status()

2022-04-13T18:03:18Z

[ Upstream commit d3c15033b240767d0287f1c4a529cbbe2d5ded8a ] Both call_transmit() and call_bc_transmit() can now return ENOMEM, so let's make sure that we handle the errors gracefully. Fixes: 0472e4766049 ("SUNRPC: Convert socket page send code to use iov_iter()") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: Fix socket waits for write buffer space

2022-04-13T18:03:11Z

[ Upstream commit 7496b59f588dd52886fdbac7633608097543a0a5 ] The socket layer requires that we use the socket lock to protect changes to the sock->sk_write_pending field and others. Reported-by: Chuck Lever Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: remove scheduling boost for "SWAPPER" tasks.

2022-04-13T18:03:10Z

[ Upstream commit a80a8461868905823609be97f91776a26befe839 ] Currently, tasks marked as "swapper" tasks get put to the front of non-priority rpc_queues, and are sorted earlier than non-swapper tasks on the transport's ->xmit_queue. This is pointless as currently *all* tasks for a mount that has swap enabled on *any* file are marked as "swapper" tasks. So the net result is that the non-priority rpc_queues are reverse-ordered (LIFO). This scheduling boost is not necessary to avoid deadlocks, and hurts fairness, so remove it. If there were a need to expedite some requests, the tk_priority mechanism is a more appropriate tool. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC/xprt: async tasks mustn't block waiting for memory

2022-04-13T18:03:10Z

[ Upstream commit a721035477fb5fb8abc738fbe410b07c12af3dc5 ] When memory is short, new worker threads cannot be created and we depend on the minimum one rpciod thread to be able to handle everything. So it must not block waiting for memory. xprt_dynamic_alloc_slot can block indefinitely. This can tie up all workqueue threads and NFS can deadlock. So when called from a workqueue, set __GFP_NORETRY. The rdma alloc_slot already does not block. However it sets the error to -EAGAIN suggesting this will trigger a sleep. It does not. As we can see in call_reserveresult(), only -ENOMEM causes a sleep. -EAGAIN causes immediate retry. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC don't resend a task on an offlined transport

2022-04-08T12:06:28Z

[ Upstream commit 82ee41b85cef16b4be1f4732650012d9baaedddd ] When a task is being retried, due to an NFS error, if the assigned transport has been put offline and the task is relocatable pick a new transport. Fixes: 6f081693e7b2b ("sunrpc: remove an offlined xprt using sysfs") Signed-off-by: Olga Kornievskaia Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: Don't call connect() more than once on a TCP socket

2022-04-08T12:06:28Z

[ Upstream commit 89f42494f92f448747bd8a7ab1ae8b5d5520577d ] Avoid socket state races due to repeated calls to ->connect() using the same socket. If connect() returns 0 due to the connection having completed, but we are in fact in a closing state, then we may leave the XPRT_CONNECTING flag set on the transport. Reported-by: Enrico Scholz Fixes: 3be232f11a3c ("SUNRPC: Prevent immediate close+reconnect") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

SUNRPC: improve 'swap' handling: scheduling and PF_MEMALLOC

2022-04-08T12:06:28Z

[ Upstream commit 8db55a032ac7ac1ed7b98d6b1dc980e6378c652f ] rpc tasks can be marked as RPC_TASK_SWAPPER. This causes GFP_MEMALLOC to be used for some allocations. This is needed in some cases, but not in all where it is currently provided, and in some where it isn't provided. Currently *all* tasks associated with a rpc_client on which swap is enabled get the flag and hence some GFP_MEMALLOC support. GFP_MEMALLOC is provided for ->buf_alloc() but only swap-writes need it. However xdr_alloc_bvec does not get GFP_MEMALLOC - though it often does need it. xdr_alloc_bvec is called while the XPRT_LOCK is held. If this blocks, then it blocks all other queued tasks. So this allocation needs GFP_MEMALLOC for *all* requests, not just writes, when the xprt is used for any swap writes. Similarly, if the transport is not connected, that will block all requests including swap writes, so memory allocations should get GFP_MEMALLOC if swap writes are possible. So with this patch: 1/ we ONLY set RPC_TASK_SWAPPER for swap writes. 2/ __rpc_execute() sets PF_MEMALLOC while handling any task with RPC_TASK_SWAPPER set, or when handling any task that holds the XPRT_LOCKED lock on an xprt used for swap. This removes the need for the RPC_IS_SWAPPER() test in ->buf_alloc handlers. 3/ xprt_prepare_transmit() sets PF_MEMALLOC after locking any task to a swapper xprt. __rpc_execute() will clear it. 3/ PF_MEMALLOC is set for all the connect workers. Reviewed-by: Chuck Lever (for xprtrdma parts) Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin