user/sven/linux.git/include/linux/sunrpc, branch v6.1.13

SUNRPC: ensure the matching upcall is in-flight upon downcall

2023-01-12T11:01:56Z

[ Upstream commit b18cba09e374637a0a3759d856a6bca94c133952 ] Commit 9130b8dbc6ac ("SUNRPC: allow for upcalls for the same uid but different gss service") introduced `auth` argument to __gss_find_upcall(), but in gss_pipe_downcall() it was left as NULL since it (and auth->service) was not (yet) determined. When multiple upcalls with the same uid and different service are ongoing, it could happen that __gss_find_upcall(), which returns the first match found in the pipe->in_downcall list, could not find the correct gss_msg corresponding to the downcall we are looking for. Moreover, it might return a msg which is not sent to rpc.gssd yet. We could see mount.nfs process hung in D state with multiple mount.nfs are executed in parallel. The call trace below is of CentOS 7.9 kernel-3.10.0-1160.24.1.el7.x86_64 but we observed the same hang w/ elrepo kernel-ml-6.0.7-1.el7. PID: 71258 TASK: ffff91ebd4be0000 CPU: 36 COMMAND: "mount.nfs" #0 [ffff9203ca3234f8] __schedule at ffffffffa3b8899f #1 [ffff9203ca323580] schedule at ffffffffa3b88eb9 #2 [ffff9203ca323590] gss_cred_init at ffffffffc0355818 [auth_rpcgss] #3 [ffff9203ca323658] rpcauth_lookup_credcache at ffffffffc0421ebc [sunrpc] #4 [ffff9203ca3236d8] gss_lookup_cred at ffffffffc0353633 [auth_rpcgss] #5 [ffff9203ca3236e8] rpcauth_lookupcred at ffffffffc0421581 [sunrpc] #6 [ffff9203ca323740] rpcauth_refreshcred at ffffffffc04223d3 [sunrpc] #7 [ffff9203ca3237a0] call_refresh at ffffffffc04103dc [sunrpc] #8 [ffff9203ca3237b8] __rpc_execute at ffffffffc041e1c9 [sunrpc] #9 [ffff9203ca323820] rpc_execute at ffffffffc0420a48 [sunrpc] The scenario is like this. Let's say there are two upcalls for services A and B, A -> B in pipe->in_downcall, B -> A in pipe->pipe. When rpc.gssd reads pipe to get the upcall msg corresponding to service B from pipe->pipe and then writes the response, in gss_pipe_downcall the msg corresponding to service A will be picked because only uid is used to find the msg and it is before the one for B in pipe->in_downcall. And the process waiting for the msg corresponding to service A will be woken up. Actual scheduing of that process might be after rpc.gssd processes the next msg. In rpc_pipe_generic_upcall it clears msg->errno (for A). The process is scheduled to see gss_msg->ctx == NULL and gss_msg->msg.errno == 0, therefore it cannot break the loop in gss_create_upcall and is never woken up after that. This patch adds a simple check to ensure that a msg which is not sent to rpc.gssd yet is not chosen as the matching upcall upon receiving a downcall. Signed-off-by: minoura makoto Signed-off-by: Hiroshi Shimamoto Tested-by: Hiroshi Shimamoto Cc: Trond Myklebust Fixes: 9130b8dbc6ac ("SUNRPC: allow for upcalls for same uid but different gss service") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

Merge tag 'nfs-for-6.1-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2022-10-13T16:58:42Z

Pull NFS client updates from Anna Schumaker: "New Features: - Add NFSv4.2 xattr tracepoints - Replace xprtiod WQ in rpcrdma - Flexfiles cancels I/O on layout recall or revoke Bugfixes and Cleanups: - Directly use ida_alloc() / ida_free() - Don't open-code max_t() - Prefer using strscpy over strlcpy - Remove unused forward declarations - Always return layout states on flexfiles layout return - Have LISTXATTR treat NFS4ERR_NOXATTR as an empty reply instead of error - Allow more xprtrdma memory allocations to fail without triggering a reclaim - Various other xprtrdma clean ups - Fix rpc_killall_tasks() races" * tag 'nfs-for-6.1-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (27 commits) NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked SUNRPC: Add API to force the client to disconnect SUNRPC: Add a helper to allow pNFS drivers to selectively cancel RPC calls SUNRPC: Fix races with rpc_killall_tasks() xprtrdma: Fix uninitialized variable xprtrdma: Prevent memory allocations from driving a reclaim xprtrdma: Memory allocation should be allowed to fail during connect xprtrdma: MR-related memory allocation should be allowed to fail xprtrdma: Clean up synopsis of rpcrdma_regbuf_alloc() xprtrdma: Clean up synopsis of rpcrdma_req_create() svcrdma: Clean up RPCRDMA_DEF_GFP SUNRPC: Replace the use of the xprtiod WQ in rpcrdma NFSv4.2: Add a tracepoint for listxattr NFSv4.2: Add tracepoints for getxattr, setxattr, and removexattr NFSv4.2: Move TRACE_DEFINE_ENUM(NFS4_CONTENT_*) under CONFIG_NFS_V4_2 NFSv4.2: Add special handling for LISTXATTR receiving NFS4ERR_NOXATTR nfs: remove nfs_wait_atomic_killable() and nfs_write_prepare() declaration NFSv4: remove nfs4_renewd_prepare_shutdown() declaration fs/nfs/pnfs_nfs.c: fix spelling typo and syntax error in comment NFSv4/pNFS: Always return layout stats on layout return for flexfiles ...

Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2022-10-10T16:10:28Z

Pull scheduler updates from Ingo Molnar: "Debuggability: - Change most occurances of BUG_ON() to WARN_ON_ONCE() - Reorganize & fix TASK_ state comparisons, turn it into a bitmap - Update/fix misc scheduler debugging facilities Load-balancing & regular scheduling: - Improve the behavior of the scheduler in presence of lot of SCHED_IDLE tasks - in particular they should not impact other scheduling classes. - Optimize task load tracking, cleanups & fixes - Clean up & simplify misc load-balancing code Freezer: - Rewrite the core freezer to behave better wrt thawing and be simpler in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting all the fallout. Deadline scheduler: - Fix the DL capacity-aware code - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period() - Relax/optimize locking in task_non_contending() Cleanups: - Factor out the update_current_exec_runtime() helper - Various cleanups, simplifications" * tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) sched: Fix more TASK_state comparisons sched: Fix TASK_state comparisons sched/fair: Move call to list_last_entry() in detach_tasks sched/fair: Cleanup loop_max and loop_break sched/fair: Make sure to try to detach at least one movable task sched: Show PF_flag holes freezer,sched: Rewrite core freezer logic sched: Widen TAKS_state literals sched/wait: Add wait_event_state() sched/completion: Add wait_for_completion_state() sched: Add TASK_ANY for wait_task_inactive() sched: Change wait_task_inactive()s match_state freezer,umh: Clean up freezer/initrd interaction freezer: Have {,un}lock_system_sleep() save/restore flags sched: Rename task_running() to task_on_cpu() sched/fair: Cleanup for SIS_PROP sched/fair: Default to false in test_idle_cores() sched/fair: Remove useless check in select_idle_core() sched/fair: Avoid double search on same cpu sched/fair: Remove redundant check in select_idle_smt() ...

SUNRPC: Add API to force the client to disconnect

2022-10-06T13:52:09Z

Allow the caller to force a disconnection of the RPC client so that we can clear any pending requests that are buffered in the socket. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Add a helper to allow pNFS drivers to selectively cancel RPC calls

2022-10-06T13:52:09Z

Add the helper rpc_cancel_tasks(), which uses a caller-defined selection function to define a set of in-flight RPC calls to cancel. This is mainly intended for pNFS drivers which are subject to a layout recall, and which may therefore want to cancel all pending I/O using that layout in order to redrive it after the layout recall has been satisfied. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

SUNRPC: Fix races with rpc_killall_tasks()

2022-10-06T13:52:09Z

Ensure that we immediately call rpc_exit_task() after waking up, and that the tk_rpc_status cannot get clobbered by some other function. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFSD: Refactor common code out of dirlist helpers

2022-09-26T18:02:47Z

The dust has settled a bit and it's become obvious what code is totally common between nfsd_init_dirlist_pages() and nfsd3_init_dirlist_pages(). Move that common code to SUNRPC. The new helper brackets the existing xdr_init_decode_pages() API. Signed-off-by: Chuck Lever

SUNRPC: Parametrize how much of argsize should be zeroed

2022-09-26T18:02:42Z

Currently, SUNRPC clears the whole of .pc_argsize before processing each incoming RPC transaction. Add an extra parameter to struct svc_procedure to enable upper layers to reduce the amount of each operation's argument structure that is zeroed by SUNRPC. The size of struct nfsd4_compoundargs, in particular, is a lot to clear on each incoming RPC Call. A subsequent patch will cut this down to something closer to what NFSv2 and NFSv3 uses. This patch should cause no behavior changes. Signed-off-by: Chuck Lever

SUNRPC: Fix svcxdr_init_encode's buflen calculation

2022-09-26T18:02:26Z

Commit 2825a7f90753 ("nfsd4: allow encoding across page boundaries") added an explicit computation of the remaining length in the rq_res XDR buffer. The computation appears to suffer from an "off-by-one" bug. Because buflen is too large by one page, XDR encoding can run off the end of the send buffer by eventually trying to use the struct page address in rq_page_end, which always contains NULL. Fixes: bddfdbcddbe2 ("NFSD: Extract the svcxdr_init_encode() helper") Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

SUNRPC: Fix svcxdr_init_decode's end-of-buffer calculation

2022-09-26T18:02:25Z

Ensure that stream-based argument decoding can't go past the actual end of the receive buffer. xdr_init_decode's calculation of the value of xdr->end over-estimates the end of the buffer because the Linux kernel RPC server code does not remove the size of the RPC header from rqstp->rq_arg before calling the upper layer's dispatcher. The server-side still uses the svc_getnl() macros to decode the RPC call header. These macros reduce the length of the head iov but do not update the total length of the message in the buffer (buf->len). A proper fix for this would be to replace the use of svc_getnl() and friends in the RPC header decoder, but that would be a large and invasive change that would be difficult to backport. Fixes: 5191955d6fc6 ("SUNRPC: Prepare for xdr_stream-style decoding on the server-side") Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever