From 5623ecfcbec165f040a23248d39680f0cc5c0854 Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 6 Sep 2023 16:05:26 -0400 Subject: [PATCH 1/6] SUNRPC: Fail quickly when server does not recognize TLS rpcauth_checkverf() should return a distinct error code when a server recognizes the AUTH_TLS probe but does not support TLS so that the client's header decoder can respond appropriately and quickly. No retries are necessary is in this case, since the server has already affirmatively answered "TLS is unsupported". Suggested-by: Trond Myklebust Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/auth.c | 11 ++++++++--- net/sunrpc/auth_tls.c | 4 ++-- net/sunrpc/clnt.c | 10 +++++++++- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 2f16f9d17966..814b0169f972 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -769,9 +769,14 @@ int rpcauth_wrap_req(struct rpc_task *task, struct xdr_stream *xdr) * @task: controlling RPC task * @xdr: xdr_stream containing RPC Reply header * - * On success, @xdr is updated to point past the verifier and - * zero is returned. Otherwise, @xdr is in an undefined state - * and a negative errno is returned. + * Return values: + * %0: Verifier is valid. @xdr now points past the verifier. + * %-EIO: Verifier is corrupted or message ended early. + * %-EACCES: Verifier is intact but not valid. + * %-EPROTONOSUPPORT: Server does not support the requested auth type. + * + * When a negative errno is returned, @xdr is left in an undefined + * state. */ int rpcauth_checkverf(struct rpc_task *task, struct xdr_stream *xdr) diff --git a/net/sunrpc/auth_tls.c b/net/sunrpc/auth_tls.c index de7678f8a23d..87f570fd3b00 100644 --- a/net/sunrpc/auth_tls.c +++ b/net/sunrpc/auth_tls.c @@ -129,9 +129,9 @@ static int tls_validate(struct rpc_task *task, struct xdr_stream *xdr) if (*p != rpc_auth_null) return -EIO; if (xdr_stream_decode_opaque_inline(xdr, &str, starttls_len) != starttls_len) - return -EIO; + return -EPROTONOSUPPORT; if (memcmp(str, starttls_token, starttls_len)) - return -EIO; + return -EPROTONOSUPPORT; return 0; } diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index 37b0b212b934..ea12ed3c70ba 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2725,7 +2725,15 @@ out_unparsable: out_verifier: trace_rpc_bad_verifier(task); - goto out_garbage; + switch (error) { + case -EPROTONOSUPPORT: + goto out_err; + case -EACCES: + /* Re-encode with a fresh cred */ + fallthrough; + default: + goto out_garbage; + } out_msg_denied: error = -EACCES; From ed1cc05aa1f7fe8197d300e914afc28ab9818f89 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 17 Sep 2023 19:05:50 -0400 Subject: [PATCH 2/6] NFSv4: Fix a nfs4_state_manager() race If the NFS4CLNT_RUN_MANAGER flag got set just before we cleared NFS4CLNT_MANAGER_RUNNING, then we might have won the race against nfs4_schedule_state_manager(), and are responsible for handling the recovery situation. Fixes: aeabb3c96186 ("NFSv4: Fix a NFSv4 state manager deadlock") Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/nfs4state.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index e079987af4a3..0bc160fbabec 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -2703,6 +2703,13 @@ static void nfs4_state_manager(struct nfs_client *clp) nfs4_end_drain_session(clp); nfs4_clear_state_manager_bit(clp); + if (test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) && + !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, + &clp->cl_state)) { + memflags = memalloc_nofs_save(); + continue; + } + if (!test_and_set_bit(NFS4CLNT_RECALL_RUNNING, &clp->cl_state)) { if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) { nfs_client_return_marked_delegations(clp); From 956fd46f97d238032cb5fa4771cdaccc6e760f9a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 24 Sep 2023 13:14:15 -0400 Subject: [PATCH 3/6] NFSv4: Fix a state manager thread deadlock regression Commit 4dc73c679114 reintroduces the deadlock that was fixed by commit aeabb3c96186 ("NFSv4: Fix a NFSv4 state manager deadlock") because it prevents the setup of new threads to handle reboot recovery, while the older recovery thread is stuck returning delegations. Fixes: 4dc73c679114 ("NFSv4: keep state manager thread active if swap is enabled") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- fs/nfs/nfs4proc.c | 4 +++- fs/nfs/nfs4state.c | 38 ++++++++++++++++++++++++++------------ 2 files changed, 29 insertions(+), 13 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 3508d8238826..7016eaadf555 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -10622,7 +10622,9 @@ static void nfs4_disable_swap(struct inode *inode) */ struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; - nfs4_schedule_state_manager(clp); + set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state); + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); + wake_up_var(&clp->cl_state); } static const struct inode_operations nfs4_dir_inode_operations = { diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 0bc160fbabec..9a5d911a7edc 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1209,16 +1209,26 @@ void nfs4_schedule_state_manager(struct nfs_client *clp) { struct task_struct *task; char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1]; + struct rpc_clnt *clnt = clp->cl_rpcclient; + bool swapon = false; - if (clp->cl_rpcclient->cl_shutdown) + if (clnt->cl_shutdown) return; set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state); - if (test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) != 0) { - wake_up_var(&clp->cl_state); - return; + + if (atomic_read(&clnt->cl_swapper)) { + swapon = !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, + &clp->cl_state); + if (!swapon) { + wake_up_var(&clp->cl_state); + return; + } } - set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state); + + if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) + return; + __module_get(THIS_MODULE); refcount_inc(&clp->cl_count); @@ -1235,8 +1245,9 @@ void nfs4_schedule_state_manager(struct nfs_client *clp) __func__, PTR_ERR(task)); if (!nfs_client_init_is_complete(clp)) nfs_mark_client_ready(clp, PTR_ERR(task)); + if (swapon) + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); nfs4_clear_state_manager_bit(clp); - clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); nfs_put_client(clp); module_put(THIS_MODULE); } @@ -2748,22 +2759,25 @@ static int nfs4_run_state_manager(void *ptr) allow_signal(SIGKILL); again: - set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state); nfs4_state_manager(clp); - if (atomic_read(&cl->cl_swapper)) { + + if (test_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state) && + !test_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) { wait_var_event_interruptible(&clp->cl_state, test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state)); - if (atomic_read(&cl->cl_swapper) && - test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state)) + if (!atomic_read(&cl->cl_swapper)) + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); + if (refcount_read(&clp->cl_count) > 1 && !signalled() && + !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) goto again; /* Either no longer a swapper, or were signalled */ + clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); } - clear_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state); if (refcount_read(&clp->cl_count) > 1 && !signalled() && test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state) && - !test_and_set_bit(NFS4CLNT_MANAGER_AVAILABLE, &clp->cl_state)) + !test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state)) goto again; nfs_put_client(clp); From a275ab62606bcd894ddff09460f7d253828313dc Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 17 Sep 2023 19:26:46 -0400 Subject: [PATCH 4/6] Revert "SUNRPC dont update timeout value on connection reset" This reverts commit 88428cc4ae7abcc879295fbb19373dd76aad2bdd. The problem this commit is intended to fix was comprehensively fixed in commit 7de62bc09fe6 ("SUNRPC dont update timeout value on connection reset"). Since then, this commit has been preventing the correct timeout of soft mounted requests. Cc: stable@vger.kernel.org # 5.9.x: 09252177d5f9: SUNRPC: Handle major timeout in xprt_adjust_timeout() Cc: stable@vger.kernel.org # 5.9.x: 7de62bc09fe6: SUNRPC dont update timeout value on connection reset Cc: stable@vger.kernel.org # 5.9.x Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker --- net/sunrpc/clnt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index ea12ed3c70ba..9c210273d06b 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -2476,8 +2476,7 @@ call_status(struct rpc_task *task) goto out_exit; } task->tk_action = call_encode; - if (status != -ECONNRESET && status != -ECONNABORTED) - rpc_check_timeout(task); + rpc_check_timeout(task); return; out_exit: rpc_call_rpcerror(task, status); From 26e8bfa30dac2ccd29dd25f391dfc73475c33329 Mon Sep 17 00:00:00 2001 From: Anna Schumaker Date: Tue, 26 Sep 2023 17:03:22 -0400 Subject: [PATCH 5/6] SUNRPC/TLS: Lock the lower_xprt during the tls handshake Otherwise we run the risk of having the lower_xprt freed from underneath us, causing an oops that looks like this: [ 224.150698] BUG: kernel NULL pointer dereference, address: 0000000000000018 [ 224.150951] #PF: supervisor read access in kernel mode [ 224.151117] #PF: error_code(0x0000) - not-present page [ 224.151278] PGD 0 P4D 0 [ 224.151361] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 224.151499] CPU: 2 PID: 99 Comm: kworker/u10:6 Not tainted 6.6.0-rc3-g6465e260f487 #41264 a00b0960990fb7bc6d6a330ee03588b67f08a47b [ 224.151977] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 2/2/2022 [ 224.152216] Workqueue: xprtiod xs_tcp_tls_setup_socket [sunrpc] [ 224.152434] RIP: 0010:xs_tcp_tls_setup_socket+0x3cc/0x7e0 [sunrpc] [ 224.152643] Code: 00 00 48 8b 7c 24 08 e9 f3 01 00 00 48 83 7b c0 00 0f 85 d2 01 00 00 49 8d 84 24 f8 05 00 00 48 89 44 24 10 48 8b 00 48 89 c5 <4c> 8b 68 18 66 41 83 3f 0a 75 71 45 31 ff 4c 89 ef 31 f6 e8 5c 76 [ 224.153246] RSP: 0018:ffffb00ec060fd18 EFLAGS: 00010246 [ 224.153427] RAX: 0000000000000000 RBX: ffff8c06c2e53e40 RCX: 0000000000000001 [ 224.153652] RDX: ffff8c073bca2408 RSI: 0000000000000282 RDI: ffff8c06c259ee00 [ 224.153868] RBP: 0000000000000000 R08: ffffffff9da55aa0 R09: 0000000000000001 [ 224.154084] R10: 00000034306c30f1 R11: 0000000000000002 R12: ffff8c06c2e51800 [ 224.154300] R13: ffff8c06c355d400 R14: 0000000004208160 R15: ffff8c06c2e53820 [ 224.154521] FS: 0000000000000000(0000) GS:ffff8c073bd00000(0000) knlGS:0000000000000000 [ 224.154763] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 224.154940] CR2: 0000000000000018 CR3: 0000000062c1e000 CR4: 0000000000750ee0 [ 224.155157] PKRU: 55555554 [ 224.155244] Call Trace: [ 224.155325] [ 224.155395] ? __die_body+0x68/0xb0 [ 224.155507] ? page_fault_oops+0x34c/0x3a0 [ 224.155635] ? _raw_spin_unlock_irqrestore+0xe/0x40 [ 224.155793] ? exc_page_fault+0x7a/0x1b0 [ 224.155916] ? asm_exc_page_fault+0x26/0x30 [ 224.156047] ? xs_tcp_tls_setup_socket+0x3cc/0x7e0 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8] [ 224.156367] ? xs_tcp_tls_setup_socket+0x2fe/0x7e0 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8] [ 224.156697] ? __pfx_xs_tls_handshake_done+0x10/0x10 [sunrpc ae3a15912ae37fd51dafbdbc2dbd069117f8f5c8] [ 224.157013] process_scheduled_works+0x24e/0x450 [ 224.157158] worker_thread+0x21c/0x2d0 [ 224.157275] ? __pfx_worker_thread+0x10/0x10 [ 224.157409] kthread+0xe8/0x110 [ 224.157510] ? __pfx_kthread+0x10/0x10 [ 224.157628] ret_from_fork+0x37/0x50 [ 224.157741] ? __pfx_kthread+0x10/0x10 [ 224.157859] ret_from_fork_asm+0x1b/0x30 [ 224.157983] Reviewed-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtsock.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 71cd916e384f..a15bf2ede89b 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2672,6 +2672,10 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work) rcu_read_lock(); lower_xprt = rcu_dereference(lower_clnt->cl_xprt); rcu_read_unlock(); + + if (wait_on_bit_lock(&lower_xprt->state, XPRT_LOCKED, TASK_KILLABLE)) + goto out_unlock; + status = xs_tls_handshake_sync(lower_xprt, &upper_xprt->xprtsec); if (status) { trace_rpc_tls_not_started(upper_clnt, upper_xprt); @@ -2681,6 +2685,7 @@ static void xs_tcp_tls_setup_socket(struct work_struct *work) status = xs_tcp_tls_finish_connecting(lower_xprt, upper_transport); if (status) goto out_close; + xprt_release_write(lower_xprt, NULL); trace_rpc_socket_connect(upper_xprt, upper_transport->sock, 0); if (!xprt_test_and_set_connected(upper_xprt)) { @@ -2702,6 +2707,7 @@ out_unlock: return; out_close: + xprt_release_write(lower_xprt, NULL); rpc_shutdown_client(lower_clnt); /* xprt_force_disconnect() wakes tasks with a fixed tk_status code. From dd1b2026323a2d075ac553cecfd7a0c23c456c59 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 19 Sep 2023 09:17:28 -0400 Subject: [PATCH 6/6] nfs: decrement nrequests counter before releasing the req I hit this panic in testing: [ 6235.500016] run fstests generic/464 at 2023-09-18 22:51:24 [ 6288.410761] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 6288.412174] #PF: supervisor read access in kernel mode [ 6288.413160] #PF: error_code(0x0000) - not-present page [ 6288.413992] PGD 0 P4D 0 [ 6288.414603] Oops: 0000 [#1] PREEMPT SMP PTI [ 6288.415419] CPU: 0 PID: 340798 Comm: kworker/u18:8 Not tainted 6.6.0-rc1-gdcf620ceebac #95 [ 6288.416538] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 [ 6288.417701] Workqueue: nfsiod rpc_async_release [sunrpc] [ 6288.418676] RIP: 0010:nfs_inode_remove_request+0xc8/0x150 [nfs] [ 6288.419836] Code: ff ff 48 8b 43 38 48 8b 7b 10 a8 04 74 5b 48 85 ff 74 56 48 8b 07 a9 00 00 08 00 74 58 48 8b 07 f6 c4 10 74 50 e8 c8 44 b3 d5 <48> 8b 00 f0 48 ff 88 30 ff ff ff 5b 5d 41 5c c3 cc cc cc cc 48 8b [ 6288.422389] RSP: 0018:ffffbd618353bda8 EFLAGS: 00010246 [ 6288.423234] RAX: 0000000000000000 RBX: ffff9a29f9a25280 RCX: 0000000000000000 [ 6288.424351] RDX: ffff9a29f9a252b4 RSI: 000000000000000b RDI: ffffef41448e3840 [ 6288.425345] RBP: ffffef41448e3840 R08: 0000000000000038 R09: ffffffffffffffff [ 6288.426334] R10: 0000000000033f80 R11: ffff9a2a7fffa000 R12: ffff9a29093f98c4 [ 6288.427353] R13: 0000000000000000 R14: ffff9a29230f62e0 R15: ffff9a29230f62d0 [ 6288.428358] FS: 0000000000000000(0000) GS:ffff9a2a77c00000(0000) knlGS:0000000000000000 [ 6288.429513] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6288.430427] CR2: 0000000000000000 CR3: 0000000264748002 CR4: 0000000000770ef0 [ 6288.431553] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6288.432715] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6288.433698] PKRU: 55555554 [ 6288.434196] Call Trace: [ 6288.434667] [ 6288.435132] ? __die+0x1f/0x70 [ 6288.435723] ? page_fault_oops+0x159/0x450 [ 6288.436389] ? try_to_wake_up+0x98/0x5d0 [ 6288.437044] ? do_user_addr_fault+0x65/0x660 [ 6288.437728] ? exc_page_fault+0x7a/0x180 [ 6288.438368] ? asm_exc_page_fault+0x22/0x30 [ 6288.439137] ? nfs_inode_remove_request+0xc8/0x150 [nfs] [ 6288.440112] ? nfs_inode_remove_request+0xa0/0x150 [nfs] [ 6288.440924] nfs_commit_release_pages+0x16e/0x340 [nfs] [ 6288.441700] ? __pfx_call_transmit+0x10/0x10 [sunrpc] [ 6288.442475] ? _raw_spin_lock_irqsave+0x23/0x50 [ 6288.443161] nfs_commit_release+0x15/0x40 [nfs] [ 6288.443926] rpc_free_task+0x36/0x60 [sunrpc] [ 6288.444741] rpc_async_release+0x29/0x40 [sunrpc] [ 6288.445509] process_one_work+0x171/0x340 [ 6288.446135] worker_thread+0x277/0x3a0 [ 6288.446724] ? __pfx_worker_thread+0x10/0x10 [ 6288.447376] kthread+0xf0/0x120 [ 6288.447903] ? __pfx_kthread+0x10/0x10 [ 6288.448500] ret_from_fork+0x2d/0x50 [ 6288.449078] ? __pfx_kthread+0x10/0x10 [ 6288.449665] ret_from_fork_asm+0x1b/0x30 [ 6288.450283] [ 6288.450688] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc nls_iso8859_1 nls_cp437 vfat fat 9p netfs ext4 kvm_intel crc16 mbcache jbd2 joydev kvm xfs irqbypass virtio_net pcspkr net_failover psmouse failover 9pnet_virtio cirrus drm_shmem_helper virtio_balloon drm_kms_helper button evdev drm loop dm_mod zram zsmalloc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel sha512_ssse3 sha512_generic virtio_blk nvme aesni_intel crypto_simd cryptd nvme_core t10_pi i6300esb crc64_rocksoft_generic crc64_rocksoft crc64 virtio_pci virtio virtio_pci_legacy_dev virtio_pci_modern_dev virtio_ring serio_raw btrfs blake2b_generic libcrc32c crc32c_generic crc32c_intel xor raid6_pq autofs4 [ 6288.460211] CR2: 0000000000000000 [ 6288.460787] ---[ end trace 0000000000000000 ]--- [ 6288.461571] RIP: 0010:nfs_inode_remove_request+0xc8/0x150 [nfs] [ 6288.462500] Code: ff ff 48 8b 43 38 48 8b 7b 10 a8 04 74 5b 48 85 ff 74 56 48 8b 07 a9 00 00 08 00 74 58 48 8b 07 f6 c4 10 74 50 e8 c8 44 b3 d5 <48> 8b 00 f0 48 ff 88 30 ff ff ff 5b 5d 41 5c c3 cc cc cc cc 48 8b [ 6288.465136] RSP: 0018:ffffbd618353bda8 EFLAGS: 00010246 [ 6288.465963] RAX: 0000000000000000 RBX: ffff9a29f9a25280 RCX: 0000000000000000 [ 6288.467035] RDX: ffff9a29f9a252b4 RSI: 000000000000000b RDI: ffffef41448e3840 [ 6288.468093] RBP: ffffef41448e3840 R08: 0000000000000038 R09: ffffffffffffffff [ 6288.469121] R10: 0000000000033f80 R11: ffff9a2a7fffa000 R12: ffff9a29093f98c4 [ 6288.470109] R13: 0000000000000000 R14: ffff9a29230f62e0 R15: ffff9a29230f62d0 [ 6288.471106] FS: 0000000000000000(0000) GS:ffff9a2a77c00000(0000) knlGS:0000000000000000 [ 6288.472216] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6288.473059] CR2: 0000000000000000 CR3: 0000000264748002 CR4: 0000000000770ef0 [ 6288.474096] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6288.475097] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6288.476148] PKRU: 55555554 [ 6288.476665] note: kworker/u18:8[340798] exited with irqs disabled Once we've released "req", it's not safe to dereference it anymore. Decrement the nrequests counter before dropping the reference. Signed-off-by: Jeff Layton Reviewed-by: Benjamin Coddington Tested-by: Benjamin Coddington Signed-off-by: Anna Schumaker --- fs/nfs/write.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 8c1ee1a1a28f..7720b5e43014 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -802,8 +802,8 @@ static void nfs_inode_remove_request(struct nfs_page *req) } if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { - nfs_release_request(req); atomic_long_dec(&NFS_I(nfs_page_to_inode(req))->nrequests); + nfs_release_request(req); } }