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2024-12-20nfsd: restore callback functionality for NFSv4.0NeilBrown
A recent patch inadvertently broke callbacks for NFSv4.0. In the 4.0 case we do not expect a session to be found but still need to call setup_callback_client() which will not try to dereference it. This patch moves the check for failure to find a session into the 4.1+ branch of setup_callback_client() Fixes: 1e02c641c3a4 ("NFSD: Prevent NULL dereference in nfsd4_process_cb_update()") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-12-17NFSD: fix management of pending async copiesOlga Kornievskaia
Currently the pending_async_copies count is decremented just before a struct nfsd4_copy is destroyed. After commit aa0ebd21df9c ("NFSD: Add nfsd4_copy time-to-live") nfsd4_copy structures sticks around for 10 lease periods after the COPY itself has completed, the pending_async_copies count stays high for a long time. This causes NFSD to avoid the use of background copy even though the actual background copy workload might no longer be running. In this patch, decrement pending_async_copies once async copy thread is done processing the copy work. Fixes: aa0ebd21df9c ("NFSD: Add nfsd4_copy time-to-live") Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-12-17nfsd: Revert "nfsd: release svc_expkey/svc_export with rcu_work"Yang Erkun
This reverts commit f8c989a0c89a75d30f899a7cabdc14d72522bb8d. Before this commit, svc_export_put or expkey_put will call path_put with sync mode. After this commit, path_put will be called with async mode. And this can lead the unexpected results show as follow. mkfs.xfs -f /dev/sda echo "/ *(rw,no_root_squash,fsid=0)" > /etc/exports echo "/mnt *(rw,no_root_squash,fsid=1)" >> /etc/exports exportfs -ra service nfs-server start mount -t nfs -o vers=4.0 127.0.0.1:/mnt /mnt1 mount /dev/sda /mnt/sda touch /mnt1/sda/file exportfs -r umount /mnt/sda # failed unexcepted The touch will finally call nfsd_cross_mnt, add refcount to mount, and then add cache_head. Before this commit, exportfs -r will call cache_flush to cleanup all cache_head, and path_put in svc_export_put/expkey_put will be finished with sync mode. So, the latter umount will always success. However, after this commit, path_put will be called with async mode, the latter umount may failed, and if we add some delay, umount will success too. Personally I think this bug and should be fixed. We first revert before bugfix patch, and then fix the original bug with a different way. Fixes: f8c989a0c89a ("nfsd: release svc_expkey/svc_export with rcu_work") Signed-off-by: Yang Erkun <yangerkun@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: allow for up to 32 callback session slotsJeff Layton
nfsd currently only uses a single slot in the callback channel, which is proving to be a bottleneck in some cases. Widen the callback channel to a max of 32 slots (subject to the client's target_maxreqs value). Change the cb_holds_slot boolean to an integer that tracks the current slot number (with -1 meaning "unassigned"). Move the callback slot tracking info into the session. Add a new u32 that acts as a bitmap to track which slots are in use, and a u32 to track the latest callback target_slotid that the client reports. To protect the new fields, add a new per-session spinlock (the se_lock). Fix nfsd41_cb_get_slot to always search for the lowest slotid (using ffs()). Finally, convert the session->se_cb_seq_nr field into an array of ints and add the necessary handling to ensure that the seqids get reset when the slot table grows after shrinking. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfs_common: must not hold RCU while calling nfsd_file_put_localMike Snitzer
Move holding the RCU from nfs_to_nfsd_file_put_local to nfs_to_nfsd_net_put. It is the call to nfs_to->nfsd_serv_put that requires the RCU anyway (the puts for nfsd_file and netns were combined to avoid an extra indirect reference but that micro-optimization isn't possible now). This fixes xfstests generic/013 and it triggering: "Voluntary context switch within RCU read-side critical section!" [ 143.545738] Call Trace: [ 143.546206] <TASK> [ 143.546625] ? show_regs+0x6d/0x80 [ 143.547267] ? __warn+0x91/0x140 [ 143.547951] ? rcu_note_context_switch+0x496/0x5d0 [ 143.548856] ? report_bug+0x193/0x1a0 [ 143.549557] ? handle_bug+0x63/0xa0 [ 143.550214] ? exc_invalid_op+0x1d/0x80 [ 143.550938] ? asm_exc_invalid_op+0x1f/0x30 [ 143.551736] ? rcu_note_context_switch+0x496/0x5d0 [ 143.552634] ? wakeup_preempt+0x62/0x70 [ 143.553358] __schedule+0xaa/0x1380 [ 143.554025] ? _raw_spin_unlock_irqrestore+0x12/0x40 [ 143.554958] ? try_to_wake_up+0x1fe/0x6b0 [ 143.555715] ? wake_up_process+0x19/0x20 [ 143.556452] schedule+0x2e/0x120 [ 143.557066] schedule_preempt_disabled+0x19/0x30 [ 143.557933] rwsem_down_read_slowpath+0x24d/0x4a0 [ 143.558818] ? xfs_efi_item_format+0x50/0xc0 [xfs] [ 143.559894] down_read+0x4e/0xb0 [ 143.560519] xlog_cil_commit+0x1b2/0xbc0 [xfs] [ 143.561460] ? _raw_spin_unlock+0x12/0x30 [ 143.562212] ? xfs_inode_item_precommit+0xc7/0x220 [xfs] [ 143.563309] ? xfs_trans_run_precommits+0x69/0xd0 [xfs] [ 143.564394] __xfs_trans_commit+0xb5/0x330 [xfs] [ 143.565367] xfs_trans_roll+0x48/0xc0 [xfs] [ 143.566262] xfs_defer_trans_roll+0x57/0x100 [xfs] [ 143.567278] xfs_defer_finish_noroll+0x27a/0x490 [xfs] [ 143.568342] xfs_defer_finish+0x1a/0x80 [xfs] [ 143.569267] xfs_bunmapi_range+0x4d/0xb0 [xfs] [ 143.570208] xfs_itruncate_extents_flags+0x13d/0x230 [xfs] [ 143.571353] xfs_free_eofblocks+0x12e/0x190 [xfs] [ 143.572359] xfs_file_release+0x12d/0x140 [xfs] [ 143.573324] __fput+0xe8/0x2d0 [ 143.573922] __fput_sync+0x1d/0x30 [ 143.574574] nfsd_filp_close+0x33/0x60 [nfsd] [ 143.575430] nfsd_file_free+0x96/0x150 [nfsd] [ 143.576274] nfsd_file_put+0xf7/0x1a0 [nfsd] [ 143.577104] nfsd_file_put_local+0x18/0x30 [nfsd] [ 143.578070] nfs_close_local_fh+0x101/0x110 [nfs_localio] [ 143.579079] __put_nfs_open_context+0xc9/0x180 [nfs] [ 143.580031] nfs_file_clear_open_context+0x4a/0x60 [nfs] [ 143.581038] nfs_file_release+0x3e/0x60 [nfs] [ 143.581879] __fput+0xe8/0x2d0 [ 143.582464] __fput_sync+0x1d/0x30 [ 143.583108] __x64_sys_close+0x41/0x80 [ 143.583823] x64_sys_call+0x189a/0x20d0 [ 143.584552] do_syscall_64+0x64/0x170 [ 143.585240] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 143.586185] RIP: 0033:0x7f3c5153efd7 Fixes: 65f2a5c36635 ("nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: get rid of include ../internal.hAl Viro
added back in 2015 for the sake of vfs_clone_file_range(), which is in linux/fs.h these days Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: fix nfs4_openowner leak when concurrent nfsd4_open occurYang Erkun
The action force umount(umount -f) will attempt to kill all rpc_task even umount operation may ultimately fail if some files remain open. Consequently, if an action attempts to open a file, it can potentially send two rpc_task to nfs server. NFS CLIENT thread1 thread2 open("file") ... nfs4_do_open _nfs4_do_open _nfs4_open_and_get_state _nfs4_proc_open nfs4_run_open_task /* rpc_task1 */ rpc_run_task rpc_wait_for_completion_task umount -f nfs_umount_begin rpc_killall_tasks rpc_signal_task rpc_task1 been wakeup and return -512 _nfs4_do_open // while loop ... nfs4_run_open_task /* rpc_task2 */ rpc_run_task rpc_wait_for_completion_task While processing an open request, nfsd will first attempt to find or allocate an nfs4_openowner. If it finds an nfs4_openowner that is not marked as NFS4_OO_CONFIRMED, this nfs4_openowner will released. Since two rpc_task can attempt to open the same file simultaneously from the client to server, and because two instances of nfsd can run concurrently, this situation can lead to lots of memory leak. Additionally, when we echo 0 to /proc/fs/nfsd/threads, warning will be triggered. NFS SERVER nfsd1 nfsd2 echo 0 > /proc/fs/nfsd/threads nfsd4_open nfsd4_process_open1 find_or_alloc_open_stateowner // alloc oo1, stateid1 nfsd4_open nfsd4_process_open1 find_or_alloc_open_stateowner // find oo1, without NFS4_OO_CONFIRMED release_openowner unhash_openowner_locked list_del_init(&oo->oo_perclient) // cannot find this oo // from client, LEAK!!! alloc_stateowner // alloc oo2 nfsd4_process_open2 init_open_stateid // associate oo1 // with stateid1, stateid1 LEAK!!! nfs4_get_vfs_file // alloc nfsd_file1 and nfsd_file_mark1 // all LEAK!!! nfsd4_process_open2 ... write_threads ... nfsd_destroy_serv nfsd_shutdown_net nfs4_state_shutdown_net nfs4_state_destroy_net destroy_client __destroy_client // won't find oo1!!! nfsd_shutdown_generic nfsd_file_cache_shutdown kmem_cache_destroy for nfsd_file_slab and nfsd_file_mark_slab // bark since nfsd_file1 // and nfsd_file_mark1 // still alive ======================================================================= BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on __kmem_cache_shutdown() ----------------------------------------------------------------------- Slab 0xffd4000004438a80 objects=34 used=1 fp=0xff11000110e2ad28 flags=0x17ffffc0000240(workingset|head|node=0|zone=2|lastcpupid=0x1fffff) CPU: 4 UID: 0 PID: 757 Comm: sh Not tainted 6.12.0-rc6+ #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xac/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1ae/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Disabling lock debugging due to kernel taint Object 0xff11000110e2ac38 @offset=3128 Allocated in nfsd_file_do_acquire+0x20f/0xa30 [nfsd] age=1635 cpu=3 pid=800 nfsd_file_do_acquire+0x20f/0xa30 [nfsd] nfsd_file_acquire_opened+0x5f/0x90 [nfsd] nfs4_get_vfs_file+0x4c9/0x570 [nfsd] nfsd4_process_open2+0x713/0x1070 [nfsd] nfsd4_open+0x74b/0x8b0 [nfsd] nfsd4_proc_compound+0x70b/0xc20 [nfsd] nfsd_dispatch+0x1b4/0x3a0 [nfsd] svc_process_common+0x5b8/0xc50 [sunrpc] svc_process+0x2ab/0x3b0 [sunrpc] svc_handle_xprt+0x681/0xa20 [sunrpc] nfsd+0x183/0x220 [nfsd] kthread+0x199/0x1e0 ret_from_fork+0x31/0x60 ret_from_fork_asm+0x1a/0x30 Add nfs4_openowner_unhashed to help found unhashed nfs4_openowner, and break nfsd4_open process to fix this problem. Cc: stable@vger.kernel.org # v5.4+ Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Add nfsd4_copy time-to-liveChuck Lever
Keep async copy state alive for a few lease cycles after the copy completes so that OFFLOAD_STATUS returns something meaningful. This means that NFSD's client shutdown processing needs to purge any of this state that happens to be waiting to die. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Add a laundromat reaper for async copy stateChuck Lever
RFC 7862 Section 4.8 states: > A copy offload stateid will be valid until either (A) the client > or server restarts or (B) the client returns the resource by > issuing an OFFLOAD_CANCEL operation or the client replies to a > CB_OFFLOAD operation. Instead of releasing async copy state when the CB_OFFLOAD callback completes, now let it live until the next laundromat run after the callback completes. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Block DESTROY_CLIENTID only when there are ongoing async COPY operationsChuck Lever
Currently __destroy_client() consults the nfs4_client's async_copies list to determine whether there are ongoing async COPY operations. However, NFSD now keeps copy state in that list even when the async copy has completed, to enable OFFLOAD_STATUS to find the COPY results for a while after the COPY has completed. DESTROY_CLIENTID should not be blocked if the client's async_copies list contains state for only completed copy operations. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Handle an NFS4ERR_DELAY response to CB_OFFLOADChuck Lever
RFC 7862 permits callback services to respond to CB_OFFLOAD with NFS4ERR_DELAY. Currently NFSD drops the CB_OFFLOAD in that case. To improve the reliability of COPY offload, NFSD should rather send another CB_OFFLOAD completion notification. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Free async copy information in nfsd4_cb_offload_release()Chuck Lever
RFC 7862 Section 4.8 states: > A copy offload stateid will be valid until either (A) the client > or server restarts or (B) the client returns the resource by > issuing an OFFLOAD_CANCEL operation or the client replies to a > CB_OFFLOAD operation. Currently, NFSD purges the metadata for an async COPY operation as soon as the CB_OFFLOAD callback has been sent. It does not wait even for the client's CB_OFFLOAD response, as the paragraph above suggests that it should. This makes the OFFLOAD_STATUS operation ineffective during the window between the completion of an asynchronous COPY and the server's receipt of the corresponding CB_OFFLOAD response. This is important if, for example, the client responds with NFS4ERR_DELAY, or the transport is lost before the server receives the response. A client might use OFFLOAD_STATUS to query the server about the still pending asynchronous COPY, but NFSD will respond to OFFLOAD_STATUS as if it had never heard of the presented copy stateid. This patch starts to address this issue by extending the lifetime of struct nfsd4_copy at least until the server has seen the client's CB_OFFLOAD response, or the CB_OFFLOAD has timed out. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Fix nfsd4_shutdown_copy()Chuck Lever
nfsd4_shutdown_copy() is just this: while ((copy = nfsd4_get_copy(clp)) != NULL) nfsd4_stop_copy(copy); nfsd4_get_copy() bumps @copy's reference count, preventing nfsd4_stop_copy() from releasing @copy. A while loop like this usually works by removing the first element of the list, but neither nfsd4_get_copy() nor nfsd4_stop_copy() alters the async_copies list. Best I can tell, then, is that nfsd4_shutdown_copy() continues to loop until other threads manage to remove all the items from this list. The spinning loop blocks shutdown until these items are gone. Possibly the reason we haven't seen this issue in the field is because client_has_state() prevents __destroy_client() from calling nfsd4_shutdown_copy() if there are any items on this list. In a subsequent patch I plan to remove that restriction. Fixes: e0639dc5805a ("NFSD introduce async copy feature") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Add a tracepoint to record canceled async COPY operationsChuck Lever
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make nfsd4_session->se_flags a boolJeff Layton
While this holds the flags from the CREATE_SESSION request, nothing ever consults them. The only flag used is NFS4_SESSION_DEAD. Make it a simple bool instead. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: remove nfsd4_session->se_bchannelJeff Layton
This field is written and is never consulted again. Remove it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make use of warning provided by refcount_tNeilBrown
refcount_t, by design, checks for unwanted situations and provides warnings. It is rarely useful to have explicit warnings with refcount usage. In this case we have an explicit warning if a refcount_t reaches zero when decremented. Simply using refcount_dec() will provide a similar warning and also mark the refcount_t as saturated to avoid any possible use-after-free. This patch drops the warning and uses refcount_dec() instead of refcount_dec_and_test(). Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Don't fail OP_SETCLIENTID when there are too many clients.NeilBrown
Failing OP_SETCLIENTID or OP_EXCHANGE_ID should only happen if there is memory allocation failure. Putting a hard limit on the number of clients is not really helpful as it will either happen too early and prevent clients that the server can easily handle, or too late and allow clients when the server is swamped. The calculated limit is still useful for expiring courtesy clients where there are "too many" clients, but it shouldn't prevent the creation of active clients. Testing of lots of clients against small-mem servers reports repeated NFS4ERR_DELAY responses which doesn't seem helpful. There may have been reports of similar problems in production use. Also remove an outdated comment - we do use a slab cache. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18svcrdma: fix miss destroy percpu_counter in svc_rdma_proc_init()Ye Bin
There's issue as follows: RPC: Registered rdma transport module. RPC: Registered rdma backchannel transport module. RPC: Unregistered rdma transport module. RPC: Unregistered rdma backchannel transport module. BUG: unable to handle page fault for address: fffffbfff80c609a PGD 123fee067 P4D 123fee067 PUD 123fea067 PMD 10c624067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI RIP: 0010:percpu_counter_destroy_many+0xf7/0x2a0 Call Trace: <TASK> __die+0x1f/0x70 page_fault_oops+0x2cd/0x860 spurious_kernel_fault+0x36/0x450 do_kern_addr_fault+0xca/0x100 exc_page_fault+0x128/0x150 asm_exc_page_fault+0x26/0x30 percpu_counter_destroy_many+0xf7/0x2a0 mmdrop+0x209/0x350 finish_task_switch.isra.0+0x481/0x840 schedule_tail+0xe/0xd0 ret_from_fork+0x23/0x80 ret_from_fork_asm+0x1a/0x30 </TASK> If register_sysctl() return NULL, then svc_rdma_proc_cleanup() will not destroy the percpu counters which init in svc_rdma_proc_init(). If CONFIG_HOTPLUG_CPU is enabled, residual nodes may be in the 'percpu_counters' list. The above issue may occur once the module is removed. If the CONFIG_HOTPLUG_CPU configuration is not enabled, memory leakage occurs. To solve above issue just destroy all percpu counters when register_sysctl() return NULL. Fixes: 1e7e55731628 ("svcrdma: Restore read and write stats") Fixes: 22df5a22462e ("svcrdma: Convert rdma_stat_sq_starve to a per-CPU counter") Fixes: df971cd853c0 ("svcrdma: Convert rdma_stat_recv to a per-CPU counter") Signed-off-by: Ye Bin <yebin10@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18xdrgen: Remove program_stat_to_errno() call sitesChuck Lever
Refactor: Translating an on-the-wire value to a local host errno is architecturally a job for the proc function, not the XDR decoder. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18xdrgen: Update the files included in client-side source codeChuck Lever
In particular, client-side source code needs the definition of "struct rpc_procinfo" and does not want header files that pull in "struct svc_rqst". Otherwise, the source does not compile. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18xdrgen: Remove check for "nfs_ok" in C templatesChuck Lever
Obviously, "nfs_ok" is defined only for NFS protocols. Other XDR protocols won't know "nfs_ok" from Adam. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18xdrgen: Remove tracepoint call siteChuck Lever
This tracepoint was a "note to self" and is not operational. It is added only to client-side code, which so far we haven't needed. It will cause immediate breakage once we start generating client code, though, so remove it now. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: release svc_expkey/svc_export with rcu_workYang Erkun
The last reference for `cache_head` can be reduced to zero in `c_show` and `e_show`(using `rcu_read_lock` and `rcu_read_unlock`). Consequently, `svc_export_put` and `expkey_put` will be invoked, leading to two issues: 1. The `svc_export_put` will directly free ex_uuid. However, `e_show`/`c_show` will access `ex_uuid` after `cache_put`, which can trigger a use-after-free issue, shown below. ================================================================== BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd] Read of size 1 at addr ff11000010fdc120 by task cat/870 CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_address_description.constprop.0+0x2c/0x3a0 print_report+0xb9/0x280 kasan_report+0xae/0xe0 svc_export_show+0x362/0x430 [nfsd] c_show+0x161/0x390 [sunrpc] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 proc_reg_read+0xe1/0x140 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Allocated by task 830: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __kmalloc_node_track_caller_noprof+0x1bc/0x400 kmemdup_noprof+0x22/0x50 svc_export_parse+0x8a9/0xb80 [nfsd] cache_do_downcall+0x71/0xa0 [sunrpc] cache_write_procfs+0x8e/0xd0 [sunrpc] proc_reg_write+0xe1/0x140 vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 868: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x37/0x50 kfree+0xf3/0x3e0 svc_export_put+0x87/0xb0 [nfsd] cache_purge+0x17f/0x1f0 [sunrpc] nfsd_destroy_serv+0x226/0x2d0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e 2. We cannot sleep while using `rcu_read_lock`/`rcu_read_unlock`. However, `svc_export_put`/`expkey_put` will call path_put, which subsequently triggers a sleeping operation due to the following `dput`. ============================= WARNING: suspicious RCU usage 5.10.0-dirty #141 Not tainted ----------------------------- ... Call Trace: dump_stack+0x9a/0xd0 ___might_sleep+0x231/0x240 dput+0x39/0x600 path_put+0x1b/0x30 svc_export_put+0x17/0x80 e_show+0x1c9/0x200 seq_read_iter+0x63f/0x7c0 seq_read+0x226/0x2d0 vfs_read+0x113/0x2c0 ksys_read+0xc9/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Fix these issues by using `rcu_work` to help release `svc_expkey`/`svc_export`. This approach allows for an asynchronous context to invoke `path_put` and also facilitates the freeing of `uuid/exp/key` after an RCU grace period. Fixes: 9ceddd9da134 ("knfsd: Allow lockless lookups of the exports") Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18SUNRPC: make sure cache entry active before cache_showYang Erkun
The function `c_show` was called with protection from RCU. This only ensures that `cp` will not be freed. Therefore, the reference count for `cp` can drop to zero, which will trigger a refcount use-after-free warning when `cache_get` is called. To resolve this issue, use `cache_get_rcu` to ensure that `cp` remains active. ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 7 PID: 822 at lib/refcount.c:25 refcount_warn_saturate+0xb1/0x120 CPU: 7 UID: 0 PID: 822 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb1/0x120 Call Trace: <TASK> c_show+0x2fc/0x380 [sunrpc] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 proc_reg_read+0xe1/0x140 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make sure exp active before svc_export_showYang Erkun
The function `e_show` was called with protection from RCU. This only ensures that `exp` will not be freed. Therefore, the reference count for `exp` can drop to zero, which will trigger a refcount use-after-free warning when `exp_get` is called. To resolve this issue, use `cache_get_rcu` to ensure that `exp` remains active. ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 819 at lib/refcount.c:25 refcount_warn_saturate+0xb1/0x120 CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb1/0x120 ... Call Trace: <TASK> e_show+0x20b/0x230 [nfsd] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fixes: bf18f163e89c ("NFSD: Using exp_get for export getting") Cc: stable@vger.kernel.org # 4.20+ Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Remove unneeded initialization of file_lock::c.flc_flagsChuck Lever
Since commit 75c7940d2a86 ("lockd: set missing fl_flags field when retrieving args"), nlmsvc_retrieve_args() initializes the flc_flags field. svcxdr_decode_lock() no longer needs to do this. This clean up removes one dependency on the nlm_lock:fl field. No behavior change is expected. Analysis: svcxdr_decode_lock() is called by: nlm4svc_decode_testargs() nlm4svc_decode_lockargs() nlm4svc_decode_cancargs() nlm4svc_decode_unlockargs() nlm4svc_decode_testargs() is used by: - NLMPROC4_TEST and NLMPROC4_TEST_MSG, which call nlmsvc_retrieve_args() - NLMPROC4_GRANTED and NLMPROC4_GRANTED_MSG, which don't pass the lock's file_lock to the generic lock API nlm4svc_decode_lockargs() is used by: - NLMPROC4_LOCK and NLM4PROC4_LOCK_MSG, which call nlmsvc_retrieve_args() - NLMPROC4_UNLOCK and NLM4PROC4_UNLOCK_MSG, which call nlmsvc_retrieve_args() - NLMPROC4_NM_LOCK, which calls nlmsvc_retrieve_args() nlm4svc_decode_cancargs() is used by: - NLMPROC4_CANCEL and NLMPROC4_CANCEL_MSG, which call nlmsvc_retrieve_args() nlm4svc_decode_unlockargs() is used by: - NLMPROC4_UNLOCK and NLMPROC4_UNLOCK_MSG, which call nlmsvc_retrieve_args() All callers except GRANTED/GRANTED_MSG eventually call nlmsvc_retrieve_args() before using nlm_lock::fl.c.flc_flags. Thus this change is safe. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Remove unused parameter to nlmsvc_testlock()Chuck Lever
The nlm_cookie parameter has been unused since commit 09802fd2a8ca ("lockd: rip out deferred lock handling from testlock codepath"). Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Remove some snippets of unfinished codeChuck Lever
Clean up. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Remove unnecessary memset()Chuck Lever
Since commit 103cc1fafee4 ("SUNRPC: Parametrize how much of argsize should be zeroed") (and possibly long before that, even) all of the memory underlying rqstp->rq_argp is zeroed already. There's no need for the memset() in nlm4svc_decode_shareargs(). Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Remove unused typedefChuck Lever
Clean up: Looks like the last usage of this typedef was removed by commit 026fec7e7c47 ("sunrpc: properly type pc_decode callbacks") in 2017. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Cap the number of bytes copied by nfs4_reset_recoverydir()Chuck Lever
It's only current caller already length-checks the string, but let's be safe. Fixes: 0964a3d3f1aa ("[PATCH] knfsd: nfsd4 reboot dirname fix") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove unused values from nfsd4_encode_components_esc()Chuck Lever
Clean up. The computed value of @p is saved each time through the loop but is never used. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove unused results in nfsd4_encode_pathname4()Chuck Lever
Clean up. The result of "*p++" is saved, but is not used before it is overwritten. The result of xdr_encode_opaque() is saved each time through the loop but is never used. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Prevent NULL dereference in nfsd4_process_cb_update()Chuck Lever
@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no available backchannel session, setup_callback_client() will try to dereference @ses and segfault. Fixes: dcbeaa68dbbd ("nfsd4: allow backchannel recovery") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove a never-true comparisonChuck Lever
fh_size is an unsigned int, thus it can never be less than 0. Fixes: d8b26071e65e ("NFSD: simplify struct nfsfh") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove dead code in nfsd4_create_session()Chuck Lever
Clean up. AFAICT, there is no way to reach the out_free_conn label with @old set to a non-NULL value, so the expire_client(old) call is never reached and can be removed. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: refine and rename NFSD_MAY_LOCKNeilBrown
NFSD_MAY_LOCK means a few different things. - it means that GSS is not required. - it means that with NFSEXP_NOAUTHNLM, authentication is not required - it means that OWNER_OVERRIDE is allowed. None of these are specific to locking, they are specific to the NLM protocol. So: - rename to NFSD_MAY_NLM - set NFSD_MAY_OWNER_OVERRIDE and NFSD_MAY_BYPASS_GSS in nlm_fopen() so that NFSD_MAY_NLM doesn't need to imply these. - move the test on NFSEXP_NOAUTHNLM out of nfsd_permission() and into fh_verify where other special-case tests on the MAY flags happen. nfsd_permission() can be called from other places than fh_verify(), but none of these will have NFSD_MAY_NLM. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Replace use of NFSD_MAY_LOCK in nfsd4_lock()Chuck Lever
NFSv4 LOCK operations should not avoid the set of authorization checks that apply to all other NFSv4 operations. Also, the "no_auth_nlm" export option should apply only to NLM LOCK requests. It's not necessary or sensible to apply it to NFSv4 LOCK operations. Instead, set no permission bits when calling fh_verify(). Subsequent stateid processing handles authorization checks. Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: replace call_rcu by kfree_rcu for simple kmem_cache_free callbackJulia Lawall
Since SLOB was removed and since commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), it is not necessary to use call_rcu when the callback only performs kmem_cache_free. Use kfree_rcu() directly. The changes were made using Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Jeff Layton <jlayton@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18xdrgen: Add a utility for extracting XDR from RFCsChuck Lever
For convenience, copy the XDR extraction script from RFC Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Fix NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOTPali Rohár
Currently NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT do not bypass only GSS, but bypass any method. This is a problem specially for NFS3 AUTH_NULL-only exports. The purpose of NFSD_MAY_BYPASS_GSS_ON_ROOT is described in RFC 2623, section 2.3.2, to allow mounting NFS2/3 GSS-only export without authentication. So few procedures which do not expose security risk used during mount time can be called also with AUTH_NONE or AUTH_SYS, to allow client mount operation to finish successfully. The problem with current implementation is that for AUTH_NULL-only exports, the NFSD_MAY_BYPASS_GSS_ON_ROOT is active also for NFS3 AUTH_UNIX mount attempts which confuse NFS3 clients, and make them think that AUTH_UNIX is enabled and is working. Linux NFS3 client never switches from AUTH_UNIX to AUTH_NONE on active mount, which makes the mount inaccessible. Fix the NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT implementation and really allow to bypass only exports which have enabled some real authentication (GSS, TLS, or any other). The result would be: For AUTH_NULL-only export if client attempts to do mount with AUTH_UNIX flavor then it will receive access errors, which instruct client that AUTH_UNIX flavor is not usable and will either try other auth flavor (AUTH_NULL if enabled) or fails mount procedure. Similarly if client attempt to do mount with AUTH_NULL flavor and only AUTH_UNIX flavor is enabled then the client will receive access error. This should fix problems with AUTH_NULL-only or AUTH_UNIX-only exports if client attempts to mount it with other auth flavor (e.g. with AUTH_NULL for AUTH_UNIX-only export, or with AUTH_UNIX for AUTH_NULL-only export). Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Fill NFSv4.1 server implementation fields in OP_EXCHANGE_ID responsePali Rohár
NFSv4.1 OP_EXCHANGE_ID response from server may contain server implementation details (domain, name and build time) in optional nfs_impl_id4 field. Currently nfsd does not fill this field. Send these information in NFSv4.1 OP_EXCHANGE_ID response. Fill them with the same values as what is Linux NFSv4.1 client doing. Domain is hardcoded to "kernel.org", name is composed in the same way as "uname -srvm" output and build time is hardcoded to zeros. NFSv4.1 client and server implementation fields are useful for statistic purposes or for identifying type of clients and servers. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18lockd: Fix comment about NLMv3 backwards compatibilityPali Rohár
NLMv2 is completely different protocol than NLMv1 and NLMv3, and in original Sun implementation is used for RPC loopback callbacks from statd to lockd services. Linux does not use nor does not implement NLMv2. Hence, NLMv3 is not backward compatible with NLMv2. But NLMv3 is backward compatible with NLMv1. Fix comment. Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: new tracepoint for after op_func in compound processingJeff Layton
Turn nfsd_compound_encode_err tracepoint into a class and add a new nfsd_compound_op_err tracepoint. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: have nfsd4_deleg_getattr_conflict pass back write deleg pointerJeff Layton
Currently we pass back the size and whether it has been modified, but those just mirror values tracked inside the delegation. In a later patch, we'll need to get at the timestamps in the delegation too, so just pass back a reference to the write delegation, and use that to properly override values in the iattr. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop the nfsd4_fattr_args "size" fieldJeff Layton
We already have a slot for this in the kstat structure. Just overwrite that instead of keeping a copy. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop the ncf_cb_bmap fieldJeff Layton
This is always the same value, and in a later patch we're going to need to set bits in WORD2. We can simplify this code and save a little space in the delegation too. Just hardcode the bitmap in the callback encode function. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop inode parameter from nfsd4_change_attribute()Jeff Layton
The inode that nfs4_open_delegation() passes to this function is wrong, which throws off the result. The inode will end up getting a directory-style change attr instead of a regular-file-style one. Fix up nfs4_delegation_stat() to fetch STATX_MODE, and then drop the inode parameter from nfsd4_change_attribute(), since it's no longer needed. Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation") Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11xdrgen: emit maxsize macrosChuck Lever
Add "definitions" subcommand logic to emit maxsize macros in generated code. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>