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path: root/fs/nfsd/nfssvc.c
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2023-10-16NFSD: simplify error paths in nfsd_svc()NeilBrown
The error paths in nfsd_svc() are needlessly complex and can result in a final call to svc_put() without nfsd_last_thread() being called. This results in the listening sockets not being closed properly. The per-netns setup provided by nfsd_startup_new() and removed by nfsd_shutdown_net() is needed precisely when there are running threads. So we don't need nfsd_up_before. We don't need to know if it *was* up. We only need to know if any threads are left. If none are, then we must call nfsd_shutdown_net(). But we don't need to do that explicitly as nfsd_last_thread() does that for us. So simply call nfsd_last_thread() before the last svc_put() if there are no running threads. That will always do the right thing. Also discard: pr_info("nfsd: last server has exited, flushing export cache\n"); It may not be true if an attempt to start the first server failed, and it isn't particularly helpful and it simply reports normal behaviour. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16NFSD: add rpc_status netlink supportLorenzo Bianconi
Introduce rpc_status netlink support for NFSD in order to dump pending RPC requests debugging information from userspace. Closes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=366 Tested-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: change sp_nrthreads to atomic_tNeilBrown
Using an atomic_t avoids the need to take a spinlock (which can soon be removed). Choosing a thread to kill needs to be careful as we cannot set the "die now" bit atomically with the test on the count. Instead we temporarily increase the count. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: change how svc threads are asked to exit.NeilBrown
svc threads are currently stopped using kthread_stop(). This requires identifying a specific thread. However we don't care which thread stops, just as long as one does. So instead, set a flag in the svc_pool to say that a thread needs to die, and have each thread check this flag instead of calling kthread_should_stop(). The first thread to find and clear this flag then moves towards exiting. This removes an explicit dependency on sp_all_threads which will make a future patch simpler. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-09-12NFSD: fix possible oops when nfsd/pool_stats is closed.NeilBrown
If /proc/fs/nfsd/pool_stats is open when the last nfsd thread exits, then when the file is closed a NULL pointer is dereferenced. This is because nfsd_pool_stats_release() assumes that the pointer to the svc_serv cannot become NULL while a reference is held. This used to be the case but a recent patch split nfsd_last_thread() out from nfsd_put(), and clearing the pointer is done in nfsd_last_thread(). This is easily reproduced by running rpc.nfsd 8 ; ( rpc.nfsd 0;true) < /proc/fs/nfsd/pool_stats Fortunately nfsd_pool_stats_release() has easy access to the svc_serv pointer, and so can call svc_put() on it directly. Fixes: 9f28a971ee9f ("nfsd: separate nfsd_last_thread() from nfsd_put()") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: remove timeout arg from svc_recv()NeilBrown
Most svc threads have no interest in a timeout. nfsd sets it to 1 hour, but this is a wart of no significance. lockd uses the timeout so that it can call nlmsvc_retry_blocked(). It also sometimes calls svc_wake_up() to ensure this is called. So change lockd to be consistent and always use svc_wake_up() to trigger nlmsvc_retry_blocked() - using a timer instead of a timeout to svc_recv(). And change svc_recv() to not take a timeout arg. This makes the sp_threads_timedout counter always zero. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: change svc_recv() to return void.NeilBrown
svc_recv() currently returns a 0 on success or one of two errors: - -EAGAIN means no message was successfully received - -EINTR means the thread has been told to stop Previously nfsd would stop as the result of a signal as well as following kthread_stop(). In that case the difference was useful: EINTR means stop unconditionally. EAGAIN means stop if kthread_should_stop(), continue otherwise. Now threads only exit when kthread_should_stop() so we don't need the distinction. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: call svc_process() from svc_recv().NeilBrown
All callers of svc_recv() go on to call svc_process() on success. Simplify callers by having svc_recv() do that for them. This loses one call to validate_process_creds() in nfsd. That was debugging code added 14 years ago. I don't think we need to keep it. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29nfsd: separate nfsd_last_thread() from nfsd_put()NeilBrown
Now that the last nfsd thread is stopped by an explicit act of calling svc_set_num_threads() with a count of zero, we only have a limited number of places that can happen, and don't need to call nfsd_last_thread() in nfsd_put() So separate that out and call it at the two places where the number of threads is set to zero. Move the clearing of ->nfsd_serv and the call to svc_xprt_destroy_all() into nfsd_last_thread(), as they are really part of the same action. nfsd_put() is now a thin wrapper around svc_put(), so make it a static inline. nfsd_put() cannot be called after nfsd_last_thread(), so in a couple of places we have to use svc_put() instead. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29nfsd: Simplify code around svc_exit_thread() call in nfsd()NeilBrown
Previously a thread could exit asynchronously (due to a signal) so some care was needed to hold nfsd_mutex over the last svc_put() call. Now a thread can only exit when svc_set_num_threads() is called, and this is always called under nfsd_mutex. So no care is needed. Not only is the mutex held when a thread exits now, but the svc refcount is elevated, so the svc_put() in svc_exit_thread() will never be a final put, so the mutex isn't even needed at this point in the code. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29nfsd: don't allow nfsd threads to be signalled.NeilBrown
The original implementation of nfsd used signals to stop threads during shutdown. In Linux 2.3.46pre5 nfsd gained the ability to shutdown threads internally it if was asked to run "0" threads. After this user-space transitioned to using "rpc.nfsd 0" to stop nfsd and sending signals to threads was no longer an important part of the API. In commit 3ebdbe5203a8 ("SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()") (v5.17-rc1~75^2~41) we finally removed the use of signals for stopping threads, using kthread_stop() instead. This patch makes the "obvious" next step and removes the ability to signal nfsd threads - or any svc threads. nfsd stops allowing signals and we don't check for their delivery any more. This will allow for some simplification in later patches. A change worth noting is in nfsd4_ssc_setup_dul(). There was previously a signal_pending() check which would only succeed when the thread was being shut down. It should really have tested kthread_should_stop() as well. Now it just does the latter, not the former. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29NFSD: Rename struct svc_cacherepChuck Lever
The svc_ prefix is identified with the SunRPC layer. Although the duplicate reply cache caches RPC replies, it is only for the NFS protocol. Rename the struct to better reflect its purpose. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29NFSD: Remove svc_rqst::rq_cacherepChuck Lever
Over time I'd like to see NFS-specific fields moved out of struct svc_rqst, which is an RPC layer object. These fields are layering violations. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-06-18NFSD: Distinguish per-net namespace initializationChuck Lever
I find the naming of nfsd_init_net() and nfsd_startup_net() to be confusingly similar. Rename the namespace initialization and tear- down ops and add comments to distinguish their separate purposes. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20NFSD: copy the whole verifier in nfsd_copy_write_verifierChuck Lever
Currently, we're only memcpy'ing the first __be32. Ensure we copy into both words. Fixes: 91d2e9b56cf5 ("NFSD: Clean up the nfsd_net::nfssvc_boot field") Reported-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20nfsd: move reply cache initialization into nfsd startupJeff Layton
There's no need to start the reply cache before nfsd is up and running, and doing so means that we register a shrinker for every net namespace instead of just the ones where nfsd is running. Move it to the per-net nfsd startup instead. Reported-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20SUNRPC: Refactor RPC server dispatch methodChuck Lever
Currently, svcauth_gss_accept() pre-reserves response buffer space for the RPC payload length and GSS sequence number before returning to the dispatcher, which then adds the header's accept_stat field. The problem is the accept_stat field is supposed to go before the length and seq_num fields. So svcauth_gss_release() has to relocate the accept_stat value (see svcauth_gss_prepare_to_wrap()). To enable these fields to be added to the response buffer in the correct (final) order, the pointer to the accept_stat has to be made available to svcauth_gss_accept() so that it can set it before reserving space for the length and seq_num fields. As a first step, move the pointer to the location of the accept_stat field into struct svc_rqst. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20SUNRPC: Push svcxdr_init_encode() into svc_process_common()Chuck Lever
Now that all vs_dispatch functions invoke svcxdr_init_encode(), it is common code and can be pushed down into the generic RPC server. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-02-20SUNRPC: Push svcxdr_init_decode() into svc_process_common()Chuck Lever
Now that all vs_dispatch functions invoke svcxdr_init_decode(), it is common code and can be pushed down into the generic RPC server. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-22nfsd: shut down the NFSv4 state objects before the filecacheJeff Layton
Currently, we shut down the filecache before trying to clean up the stateids that depend on it. This leads to the kernel trying to free an nfsd_file twice, and a refcount overput on the nf_mark. Change the shutdown procedure to tear down all of the stateids prior to shutting down the filecache. Reported-and-tested-by: Wang Yugui <wangyugui@e16-tech.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Fixes: 5e113224c17e ("nfsd: nfsd_file cache entries should be per net namespace") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: Use only RQ_DROPME to signal the need to drop a replyChuck Lever
Clean up: NFSv2 has the only two usages of rpc_drop_reply in the NFSD code base. Since NFSv2 is going away at some point, replace these in order to simplify the "drop this reply?" check in nfsd_dispatch(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28nfsd: allow disabling NFSv2 at compile timeJeff Layton
rpc.nfsd stopped supporting NFSv2 a year ago. Take the next logical step toward deprecating it and allow NFSv2 support to be compiled out. Add a new CONFIG_NFSD_V2 option that can be turned off and rework the CONFIG_NFSD_V?_ACL option dependencies. Add a description that discourages enabling it. Also, change the description of CONFIG_NFSD to state that the always-on version is now 3 instead of 2. Finally, add an #ifdef around "case 2:" in __write_versions. When NFSv2 is disabled at compile time, this should make the kernel ignore attempts to disable it at runtime, but still error out when trying to enable it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Tom Talpey <tom@talpey.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-09-26NFSD: move from strlcpy with unused retval to strscpyWolfram Sang
Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-03-11NFSD: Remove CONFIG_NFSD_V3Chuck Lever
Eventually support for NFSv2 in the Linux NFS server is to be deprecated and then removed. However, NFSv2 is the "always supported" version that is available as soon as CONFIG_NFSD is set. Before NFSv2 support can be removed, we need to choose a different "always supported" version. This patch removes CONFIG_NFSD_V3 so that NFSv3 is always supported, as NFSv2 is today. When NFSv2 support is removed, NFSv3 will become the only "always supported" NFS version. The defconfigs still need to be updated to remove CONFIG_NFSD_V3=y. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28NFSD: Move svc_serv_ops::svo_function into struct svc_servChuck Lever
Hoist svo_function back into svc_serv and remove struct svc_serv_ops, since the struct is now devoid of fields. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28NFSD: Remove svc_serv_ops::svo_moduleChuck Lever
struct svc_serv_ops is about to be removed. Neil Brown says: > I suspect svo_module can go as well - I don't think the thread is > ever the thing that primarily keeps a module active. A random sample of kthread_create() callers shows sunrpc is the only one that manages module reference count in this way. Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28SUNRPC: Remove svc_shutdown_net()Chuck Lever
Clean up: svc_shutdown_net() now does nothing but call svc_close_net(). Replace all external call sites. svc_close_net() is renamed to be the inverse of svc_xprt_create(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28SUNRPC: Rename svc_create_xprt()Chuck Lever
Clean up: Use the "svc_xprt_<task>" function naming convention as is used for other external APIs. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-02-28SUNRPC: Remove svo_shutdown methodChuck Lever
Clean up. Neil observed that "any code that calls svc_shutdown_net() knows what the shutdown function should be, and so can call it directly." Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de>
2022-02-28SUNRPC: Remove the .svo_enqueue_xprt methodChuck Lever
We have never been able to track down and address the underlying cause of the performance issues with workqueue-based service support. svo_enqueue_xprt is called multiple times per RPC, so it adds instruction path length, but always ends up at the same function: svc_xprt_do_enqueue(). We do not anticipate needing this flexibility for dynamic nfsd thread management support. As a micro-optimization, remove .svo_enqueue_xprt because Spectre/Meltdown makes virtual function calls more costly. This change essentially reverts commit b9e13cdfac70 ("nfsd/sunrpc: turn enqueueing a svc_xprt into a svc_serv operation"). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-17Merge branch 'signal-for-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal/exit/ptrace updates from Eric Biederman: "This set of changes deletes some dead code, makes a lot of cleanups which hopefully make the code easier to follow, and fixes bugs found along the way. The end-game which I have not yet reached yet is for fatal signals that generate coredumps to be short-circuit deliverable from complete_signal, for force_siginfo_to_task not to require changing userspace configured signal delivery state, and for the ptrace stops to always happen in locations where we can guarantee on all architectures that the all of the registers are saved and available on the stack. Removal of profile_task_ext, profile_munmap, and profile_handoff_task are the big successes for dead code removal this round. A bunch of small bug fixes are included, as most of the issues reported were small enough that they would not affect bisection so I simply added the fixes and did not fold the fixes into the changes they were fixing. There was a bug that broke coredumps piped to systemd-coredump. I dropped the change that caused that bug and replaced it entirely with something much more restrained. Unfortunately that required some rebasing. Some successes after this set of changes: There are few enough calls to do_exit to audit in a reasonable amount of time. The lifetime of struct kthread now matches the lifetime of struct task, and the pointer to struct kthread is no longer stored in set_child_tid. The flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is removed. Issues where task->exit_code was examined with signal->group_exit_code should been examined were fixed. There are several loosely related changes included because I am cleaning up and if I don't include them they will probably get lost. The original postings of these changes can be found at: https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org I trimmed back the last set of changes to only the obviously correct once. Simply because there was less time for review than I had hoped" * 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits) ptrace/m68k: Stop open coding ptrace_report_syscall ptrace: Remove unused regs argument from ptrace_report_syscall ptrace: Remove second setting of PT_SEIZED in ptrace_attach taskstats: Cleanup the use of task->exit_code exit: Use the correct exit_code in /proc/<pid>/stat exit: Fix the exit_code for wait_task_zombie exit: Coredumps reach do_group_exit exit: Remove profile_handoff_task exit: Remove profile_task_exit & profile_munmap signal: clean up kernel-doc comments signal: Remove the helper signal_group_exit signal: Rename group_exit_task group_exec_task coredump: Stop setting signal->group_exit_task signal: Remove SIGNAL_GROUP_COREDUMP signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process signal: Make coredump handling explicit in complete_signal signal: Have prepare_signal detect coredumps using signal->core_state signal: Have the oom killer detect coredumps using signal->core_state exit: Move force_uaccess back into do_exit exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit ...
2022-01-08NFSD: Rename boot verifier functionsChuck Lever
Clean up: These functions handle what the specs call a write verifier, which in the Linux NFS server implementation is now divorced from the server's boot instance Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Clean up the nfsd_net::nfssvc_boot fieldChuck Lever
There are two boot-time fields in struct nfsd_net: one called boot_time and one called nfssvc_boot. The latter is used only to form write verifiers, but its documenting comment declares: /* Time of server startup */ Since commit 27c438f53e79 ("nfsd: Support the server resetting the boot verifier"), this field can be reset at any time; it's no longer tied to server restart. So that comment is stale. Also, according to pahole, struct timespec64 is 16 bytes long on x86_64. The nfssvc_boot field is used only to form a write verifier, which is 8 bytes long. Let's clarify this situation by manufacturing an 8-byte verifier in nfs_reset_boot_verifier() and storing only that in struct nfsd_net. We're grabbing 128 bits of time, so compress all of those into a 64-bit verifier instead of throwing out the high-order bits. In the future, the siphash_key can be re-used for other hashed objects per-nfsd_net. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-01-08NFSD: Write verifier might go backwardsChuck Lever
When vfs_iter_write() starts to fail because a file system is full, a bunch of writes can fail at once with ENOSPC. These writes repeatedly invoke nfsd_reset_boot_verifier() in quick succession. Ensure that the time it grabs doesn't go backwards due to an ntp adjustment going on at the same time. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: simplify locking for network notifier.NeilBrown
nfsd currently maintains an open-coded read/write semaphore (refcount and wait queue) for each network namespace to ensure the nfs service isn't shut down while the notifier is running. This is excessive. As there is unlikely to be contention between notifiers and they run without sleeping, a single spinlock is sufficient to avoid problems. Signed-off-by: NeilBrown <neilb@suse.de> [ cel: ensure nfsd_notifier_lock is static ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()NeilBrown
The ->svo_setup callback serves no purpose. It is always called from within the same module that chooses which callback is needed. So discard it and call the relevant function directly. Now that svc_set_num_threads() is no longer used remove it and rename svc_set_num_threads_sync() to remove the "_sync" suffix. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Make it possible to use svc_set_num_threads_syncNeilBrown
nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: narrow nfsd_mutex protection in nfsd threadNeilBrown
There is nothing happening in the start of nfsd() that requires protection by the mutex, so don't take it until shutting down the thread - which does still require protection - but only for nfsd_put(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: use sv_lock to protect updates to sv_nrthreads.NeilBrown
Using sv_lock means we don't need to hold the service mutex over these updates. In particular, svc_exit_thread() no longer requires synchronisation, so threads can exit asynchronously. Note that we could use an atomic_t, but as there are many more read sites than writes, that would add unnecessary noise to the code. Some reads are already racy, and there is no need for them to not be. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13nfsd: make nfsd_stats.th_cnt atomic_tNeilBrown
This allows us to move the updates for th_cnt out of the mutex. This is a step towards reducing mutex coverage in nfsd(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: stop using ->sv_nrthreads as a refcountNeilBrown
The use of sv_nrthreads as a general refcount results in clumsy code, as is seen by various comments needed to explain the situation. This patch introduces a 'struct kref' and uses that for reference counting, leaving sv_nrthreads to be a pure count of threads. The kref is managed particularly in svc_get() and svc_put(), and also nfsd_put(); svc_destroy() now takes a pointer to the embedded kref, rather than to the serv. nfsd allows the svc_serv to exist with ->sv_nrhtreads being zero. This happens when a transport is created before the first thread is started. To support this, a 'keep_active' flag is introduced which holds a ref on the svc_serv. This is set when any listening socket is successfully added (unless there are running threads), and cleared when the number of threads is set. So when the last thread exits, the nfs_serv will be destroyed. The use of 'keep_active' replaces previous code which checked if there were any permanent sockets. We no longer clear ->rq_server when nfsd() exits. This was done to prevent svc_exit_thread() from calling svc_destroy(). Instead we take an extra reference to the svc_serv to prevent svc_destroy() from being called. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC/NFSD: clean up get/put functions.NeilBrown
svc_destroy() is poorly named - it doesn't necessarily destroy the svc, it might just reduce the ref count. nfsd_destroy() is poorly named for the same reason. This patch: - removes the refcount functionality from svc_destroy(), moving it to a new svc_put(). Almost all previous callers of svc_destroy() now call svc_put(). - renames nfsd_destroy() to nfsd_put() and improves the code, using the new svc_destroy() rather than svc_put() - removes a few comments that explain the important for balanced get/put calls. This should be obvious. The only non-trivial part of this is that svc_destroy() would call svc_sock_update() on a non-final decrement. It can no longer do that, and svc_put() isn't really a good place of it. This call is now made from svc_exit_thread() which seems like a good place. This makes the call *before* sv_nrthreads is decremented rather than after. This is not particularly important as the call just sets a flag which causes sv_nrthreads set be checked later. A subsequent patch will improve the ordering. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13exit: Rename module_put_and_exit to module_put_and_kthread_exitEric W. Biederman
Update module_put_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of module_put_and_exit are causing the current kthread to exit so this change makes it clear what is happening. There is no functional change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-10-19NFSD:fix boolreturn.cocci warningChangcheng Deng
./fs/nfsd/nfssvc.c: 1072: 8-9: :WARNING return of 0/1 in function 'nfssvc_decode_voidarg' with return type bool Return statements in functions returning bool should use true/false instead of 1/0. Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Change return value type of .pc_encodeChuck Lever
Returning an undecorated integer is an age-old trope, but it's not clear (even to previous experts in this code) that the only valid return values are 1 and 0. These functions do not return a negative errno, rpc_stat value, or a positive length. Document there are only two valid return values by having .pc_encode return only true or false. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Replace the "__be32 *p" parameter to .pc_encodeChuck Lever
The passed-in value of the "__be32 *p" parameter is now unused in every server-side XDR encoder, and can be removed. Note also that there is a line in each encoder that sets up a local pointer to a struct xdr_stream. Passing that pointer from the dispatcher instead saves one line per encoder function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Change return value type of .pc_decodeChuck Lever
Returning an undecorated integer is an age-old trope, but it's not clear (even to previous experts in this code) that the only valid return values are 1 and 0. These functions do not return a negative errno, rpc_stat value, or a positive length. Document there are only two valid return values by having .pc_decode return only true or false. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-10-13SUNRPC: Replace the "__be32 *p" parameter to .pc_decodeChuck Lever
The passed-in value of the "__be32 *p" parameter is now unused in every server-side XDR decoder, and can be removed. Note also that there is a line in each decoder that sets up a local pointer to a struct xdr_stream. Passing that pointer from the dispatcher instead saves one line per decoder function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-05-25NFSD: delay unmount source's export after inter-server copy completed.Dai Ngo
Currently the source's export is mounted and unmounted on every inter-server copy operation. This patch is an enhancement to delay the unmount of the source export for a certain period of time to eliminate the mount and unmount overhead on subsequent copy operations. After a copy operation completes, a work entry is added to the delayed unmount list with an expiration time. This list is serviced by the laundromat thread to unmount the export of the expired entries. Each time the export is being used again, its expiration time is extended and the entry is re-inserted to the tail of the list. The unmount task and the mount operation of the copy request are synced to make sure the export is not unmounted while it's being used. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2021-04-15nfsd: removed unused argument in nfsd_startup_generic()Vasily Averin
Since commit 501cb1849f86 ("nfsd: rip out the raparms cache") nrservs is not used in nfsd_startup_generic() Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>