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2024-01-10Merge tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull nfs client updates from Anna Schumaker: "New Features: - Always ask for type with READDIR - Remove nfs_writepage() Bugfixes: - Fix a suspicious RCU usage warning - Fix a blocklayoutdriver reference leak - Fix the block driver's calculation of layoutget size - Fix handling NFS4ERR_RETURNCONFLICT - Fix _xprt_switch_find_current_entry() - Fix v4.1 backchannel request timeouts - Don't add zero-length pnfs block devices - Use the parent cred in nfs_access_login_time() Cleanups: - A few improvements when dealing with referring calls from the server - Clean up various unused variables, struct fields, and function calls - Various tracepoint improvements" * tag 'nfs-for-6.8-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (21 commits) NFSv4.1: Use the nfs_client's rpc timeouts for backchannel SUNRPC: Fixup v4.1 backchannel request timeouts rpc_pipefs: Replace one label in bl_resolve_deviceid() nfs: Remove writepage NFS: drop unused nfs_direct_req bytes_left pNFS: Fix the pnfs block driver's calculation of layoutget size nfs: print fileid in lookup tracepoints nfs: rename the nfs_async_rename_done tracepoint nfs: add new tracepoint at nfs4 revalidate entry point SUNRPC: fix _xprt_switch_find_current_entry logic NFSv4.1/pnfs: Ensure we handle the error NFS4ERR_RETURNCONFLICT NFSv4.1: if referring calls are complete, trust the stateid argument NFSv4: Track the number of referring calls in struct cb_process_state NFS: Use parent's objective cred in nfs_access_login_time() NFSv4: Always ask for type with READDIR pnfs/blocklayout: Don't add zero-length pnfs_block_dev blocklayoutdriver: Fix reference leak of pnfs_device_node SUNRPC: Fix a suspicious RCU usage warning SUNRPC: Create a helper function for accessing the rpc_clnt's xprt_switch SUNRPC: Remove unused function rpc_clnt_xprt_switch_put() ...
2024-01-07SUNRPC: discard sv_refcnt, and svc_get/svc_putNeilBrown
sv_refcnt is no longer useful. lockd and nfs-cb only ever have the svc active when there are a non-zero number of threads, so sv_refcnt mirrors sv_nrthreads. nfsd also keeps the svc active between when a socket is added and when the first thread is started, but we don't really need a refcount for that. We can simply not destroy the svc while there are any permanent sockets attached. So remove sv_refcnt and the get/put functions. Instead of a final call to svc_put(), call svc_destroy() instead. This is changed to also store NULL in the passed-in pointer to make it easier to avoid use-after-free situations. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svc: don't hold reference for poolstats, only mutex.NeilBrown
A future patch will remove refcounting on svc_serv as it is of little use. It is currently used to keep the svc around while the pool_stats file is open. Change this to get the pointer, protected by the mutex, only in seq_start, and the release the mutex in seq_stop. This means that if the nfsd server is stopped and restarted while the pool_stats file it open, then some pool stats info could be from the first instance and some from the second. This might appear odd, but is unlikely to be a problem in practice. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Implement multi-stage Read completion againChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (ie, the client) stops responding. We need to go back to handling RDMA Reads by getting the svc scheduler to call svc_rdma_recvfrom() a second time to finish building an RPC message after a Read completion. This is the final patch, and makes several changes that have to happen concurrently: 1. svc_rdma_process_read_list no longer waits for a completion, but simply builds and posts the Read WRs. 2. svc_rdma_read_done() now queues a completed Read on sc_read_complete_q for later processing rather than calling complete(). 3. The completed RPC message is no longer built in the svc_rdma_process_read_list() path. Finishing the message is now done in svc_rdma_recvfrom() when it notices work on the sc_read_complete_q. The "finish building this RPC message" code is removed from the svc_rdma_process_read_list() path. This arrangement avoids the need for an nfsd thread to wait for an RDMA Read non-interruptibly without a timeout. It's basically the same code structure that Tom Tucker used for Read chunks along with some clean-up and modernization. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add back svcxprt_rdma::sc_read_complete_qChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (ie, the client) stops responding. We need to go back to handling RDMA Reads by allowing the nfsd thread to return to the svc scheduler, then waking a second thread finish the RPC message once the Read completion fires. As a next step, add a list_head upon which completed Reads are queued. A subsequent patch will make use of this queue. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add back svc_rdma_recv_ctxt::rc_pagesChuck Lever
Having an nfsd thread waiting for an RDMA Read completion is problematic if the Read responder (the client) stops responding. We need to go back to handling RDMA Reads by allowing the nfsd thread to return to the svc scheduler, then waking a second thread finish the RPC message once the Read completion fires. To start with, restore the rc_pages field so that RDMA Read pages can be managed across calls to svc_rdma_recvfrom(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: De-duplicate completion ID initialization helpersChuck Lever
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Move the svc_rdma_cc_init() callChuck Lever
Now that the chunk_ctxt for Reads is no longer dynamically allocated it can be initialized once for the life of the object that contains it (struct svc_rdma_recv_ctxt). Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Update synopsis of svc_rdma_build_read_segment()Chuck Lever
Since the RDMA Read I/O state is now contained in the recv_ctxt, svc_rdma_build_read_segment() can use the recv_ctxt to derive that information rather than the other way around. This removes one usage of the ri_readctxt field, enabling its removal in a subsequent patch. At the same time, the use of ri_rqst can similarly be replaced with a passed-in function parameter. Start with build_read_segment() because it is a common utility function at the bottom of the Read chunk path. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Move read_info::ri_pageoff into struct svc_rdma_recv_ctxtChuck Lever
Further clean up: move the starting byte offset field into svc_rdma_recv_ctxt. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Move svc_rdma_read_info::ri_pageno to struct svc_rdma_recv_ctxtChuck Lever
Further clean up: move the page index field into svc_rdma_recv_ctxt. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Start moving fields out of struct svc_rdma_read_infoChuck Lever
Since the request's svc_rdma_recv_ctxt will stay around for the duration of the RDMA Read operation, the contents of struct svc_rdma_read_info can reside in the request's svc_rdma_recv_ctxt rather than being allocated separately. This will eventually save a call to kmalloc() in a hot path. Start this clean-up by moving the Read chunk's svc_rdma_chunk_ctxt. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Move struct svc_rdma_chunk_ctxt to svc_rdma.hChuck Lever
Prepare for nestling these into the send and recv ctxts so they no longer have to be allocated dynamically. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add an async version of svc_rdma_send_ctxt_put()Chuck Lever
DMA unmapping can take quite some time, so it should not be handled in a single-threaded completion handler. Defer releasing send_ctxts to the recently-added workqueue. With this patch, DMA unmapping can be handled in parallel, and it does not cause head-of-queue blocking of Send completions. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Add a utility workqueue to svcrdmaChuck Lever
To handle work in the background, set up an UNBOUND workqueue for svcrdma. Subsequent patches will make use of it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07svcrdma: Eliminate allocation of recv_ctxt objects in backchannelChuck Lever
The svc_rdma_recv_ctxt free list uses a lockless list to avoid the need for a spin lock in the fast path. llist_del_first(), which is used by svc_rdma_recv_ctxt_get(), requires serialization, however, when there are multiple list producers that are unserialized. I mistakenly thought there was only one caller of svc_rdma_recv_ctxt_get() (svc_rdma_refresh_recvs()), thus explicit serialization would not be necessary. But there is another caller: svc_rdma_bc_sendto(), and these two are not serialized against each other. I haven't seen ill effects that I could directly ascribe to a lack of serialization. It's just an observation based on code audit. When DMA-mapping before sending a Reply, the passed-in struct svc_rdma_recv_ctxt is used only for its write and reply PCLs. These are currently always empty in the backchannel case. So, instead of passing a full svc_rdma_recv_ctxt object to svc_rdma_map_reply_msg(), let's pass in just the Write and Reply PCLs. This change makes it unnecessary for the backchannel to acquire a dummy svc_rdma_recv_ctxt object when sending an RPC Call. The need for svc_rdma_recv_ctxt free list serialization is now completely avoided. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07SUNRPC: Remove RQ_SPLICE_OKChuck Lever
This flag is no longer used. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-07SUNRPC: Add a server-side API for retrieving an RPC's pseudoflavorChuck Lever
NFSD will use this new API to determine whether nfsd_splice_read is safe to use. This avoids the need to add a dependency to NFSD for CONFIG_SUNRPC_GSS. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-01-04NFSv4.1: Use the nfs_client's rpc timeouts for backchannelBenjamin Coddington
For backchannel requests that lookup the appropriate nfs_client, use the state-management rpc_clnt's rpc_timeout parameters for the backchannel's response. When the nfs_client cannot be found, fall back to using the xprt's default timeout parameters. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Tested-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-01-04SUNRPC: Remove unused function rpc_clnt_xprt_switch_put()Anna Schumaker
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-11-08Merge tag 'nfs-for-6.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Bugfixes: - SUNRPC: - re-probe the target RPC port after an ECONNRESET error - handle allocation errors from rpcb_call_async() - fix a use-after-free condition in rpc_pipefs - fix up various checks for timeouts - NFSv4.1: - Handle NFS4ERR_DELAY errors during session trunking - fix SP4_MACH_CRED protection for pnfs IO - NFSv4: - Ensure that we test all delegations when the server notifies us that it may have revoked some of them Features: - Allow knfsd processes to break out of NFS4ERR_DELAY loops when re-exporting NFSv4.x by setting appropriate values for the 'delay_retrans' module parameter - nfs: Convert nfs_symlink() to use a folio" * tag 'nfs-for-6.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: nfs: Convert nfs_symlink() to use a folio SUNRPC: Fix RPC client cleaned up the freed pipefs dentries NFSv4.1: fix SP4_MACH_CRED protection for pnfs IO SUNRPC: Add an IS_ERR() check back to where it was NFSv4.1: fix handling NFS4ERR_DELAY when testing for session trunking nfs41: drop dependency between flexfiles layout driver and NFSv3 modules NFSv4: fairly test all delegations on a SEQ4_ revocation SUNRPC: SOFTCONN tasks should time out when on the sending list SUNRPC: Force close the socket when a hard error is reported SUNRPC: Don't skip timeout checks in call_connect_status() SUNRPC: ECONNRESET might require a rebind NFSv4/pnfs: Allow layoutget to return EAGAIN for softerr mounts NFSv4: Add a parameter to limit the number of retries after NFS4ERR_DELAY
2023-11-01SUNRPC: Fix RPC client cleaned up the freed pipefs dentriesfelix
RPC client pipefs dentries cleanup is in separated rpc_remove_pipedir() workqueue,which takes care about pipefs superblock locking. In some special scenarios, when kernel frees the pipefs sb of the current client and immediately alloctes a new pipefs sb, rpc_remove_pipedir function would misjudge the existence of pipefs sb which is not the one it used to hold. As a result, the rpc_remove_pipedir would clean the released freed pipefs dentries. To fix this issue, rpc_remove_pipedir should check whether the current pipefs sb is consistent with the original pipefs sb. This error can be catched by KASAN: ========================================================= [ 250.497700] BUG: KASAN: slab-use-after-free in dget_parent+0x195/0x200 [ 250.498315] Read of size 4 at addr ffff88800a2ab804 by task kworker/0:18/106503 [ 250.500549] Workqueue: events rpc_free_client_work [ 250.501001] Call Trace: [ 250.502880] kasan_report+0xb6/0xf0 [ 250.503209] ? dget_parent+0x195/0x200 [ 250.503561] dget_parent+0x195/0x200 [ 250.503897] ? __pfx_rpc_clntdir_depopulate+0x10/0x10 [ 250.504384] rpc_rmdir_depopulate+0x1b/0x90 [ 250.504781] rpc_remove_client_dir+0xf5/0x150 [ 250.505195] rpc_free_client_work+0xe4/0x230 [ 250.505598] process_one_work+0x8ee/0x13b0 ... [ 22.039056] Allocated by task 244: [ 22.039390] kasan_save_stack+0x22/0x50 [ 22.039758] kasan_set_track+0x25/0x30 [ 22.040109] __kasan_slab_alloc+0x59/0x70 [ 22.040487] kmem_cache_alloc_lru+0xf0/0x240 [ 22.040889] __d_alloc+0x31/0x8e0 [ 22.041207] d_alloc+0x44/0x1f0 [ 22.041514] __rpc_lookup_create_exclusive+0x11c/0x140 [ 22.041987] rpc_mkdir_populate.constprop.0+0x5f/0x110 [ 22.042459] rpc_create_client_dir+0x34/0x150 [ 22.042874] rpc_setup_pipedir_sb+0x102/0x1c0 [ 22.043284] rpc_client_register+0x136/0x4e0 [ 22.043689] rpc_new_client+0x911/0x1020 [ 22.044057] rpc_create_xprt+0xcb/0x370 [ 22.044417] rpc_create+0x36b/0x6c0 ... [ 22.049524] Freed by task 0: [ 22.049803] kasan_save_stack+0x22/0x50 [ 22.050165] kasan_set_track+0x25/0x30 [ 22.050520] kasan_save_free_info+0x2b/0x50 [ 22.050921] __kasan_slab_free+0x10e/0x1a0 [ 22.051306] kmem_cache_free+0xa5/0x390 [ 22.051667] rcu_core+0x62c/0x1930 [ 22.051995] __do_softirq+0x165/0x52a [ 22.052347] [ 22.052503] Last potentially related work creation: [ 22.052952] kasan_save_stack+0x22/0x50 [ 22.053313] __kasan_record_aux_stack+0x8e/0xa0 [ 22.053739] __call_rcu_common.constprop.0+0x6b/0x8b0 [ 22.054209] dentry_free+0xb2/0x140 [ 22.054540] __dentry_kill+0x3be/0x540 [ 22.054900] shrink_dentry_list+0x199/0x510 [ 22.055293] shrink_dcache_parent+0x190/0x240 [ 22.055703] do_one_tree+0x11/0x40 [ 22.056028] shrink_dcache_for_umount+0x61/0x140 [ 22.056461] generic_shutdown_super+0x70/0x590 [ 22.056879] kill_anon_super+0x3a/0x60 [ 22.057234] rpc_kill_sb+0x121/0x200 Fixes: 0157d021d23a ("SUNRPC: handle RPC client pipefs dentries by network namespace aware routines") Signed-off-by: felix <fuzhen5@huawei.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.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 the back-channel queue to lwqNeilBrown
This removes the need to store and update back-links in the list. It also remove the need for the _bh version of spin_lock(). Signed-off-by: NeilBrown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: discard sp_lockNeilBrown
sp_lock is now only used to protect sp_all_threads. This isn't needed as sp_all_threads is only manipulated through svc_set_num_threads(), which is already serialized. Read-acccess only requires rcu_read_lock(). So no more locking is needed. Signed-off-by: NeilBrown <neilb@suse.de> 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: use lwq for sp_sockets - renamed to sp_xprtsNeilBrown
lwq avoids using back pointers in lists, and uses less locking. This introduces a new spinlock, but the other one will be removed in a future patch. For svc_clean_up_xprts(), we now dequeue the entire queue, walk it to remove and process the xprts that need cleaning up, then re-enqueue the remaining queue. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: only have one thread waking up at a timeNeilBrown
Currently if several items of work become available in quick succession, that number of threads (if available) will be woken. By the time some of them wake up another thread that was already cache-warm might have come along and completed the work. Anecdotal evidence suggests as many as 15% of wakes find nothing to do once they get to the point of looking. This patch changes svc_pool_wake_idle_thread() to wake the first thread on the queue but NOT remove it. Subsequent calls will wake the same thread. Once that thread starts it will dequeue itself and after dequeueing some work to do, it will wake the next thread if there is more work ready. This results in a more orderly increase in the number of busy threads. As a bonus, this allows us to reduce locking around the idle queue. svc_pool_wake_idle_thread() no longer needs to take a lock (beyond rcu_read_lock()) as it doesn't manipulate the queue, it just looks at the first item. The thread itself can avoid locking by using the new llist_del_first_this() interface. This will safely remove the thread itself if it is the head. If it isn't the head, it will do nothing. If multiple threads call this concurrently only one will succeed. The others will do nothing, so no corruption can result. If a thread wakes up and finds that it cannot dequeue itself that means either - that it wasn't woken because it was the head of the queue. Maybe the freezer woke it. In that case it can go back to sleep (after trying to freeze of course). - some other thread found there was nothing to do very recently, and placed itself on the head of the queue in front of this thread. It must check again after placing itself there, so it can be deemed to be responsible for any pending work, and this thread can go back to sleep until woken. No code ever tests for busy threads any more. Only each thread itself cares if it is busy. So svc_thread_busy() is no longer needed. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: change service idle list to be an llistNeilBrown
With an llist we don't need to take a lock to add a thread to the list, though we still need a lock to remove it. That will go in the next patch. Unlike double-linked lists, a thread cannot reliably remove itself from the list. Only the first thread can be removed, and that can change asynchronously. So some care is needed. We already check if there is pending work to do, so we are unlikely to add ourselves to the idle list and then want to remove ourselves again. If we DO find something needs to be done after adding ourselves to the list, we simply wake up the first thread on the list. If that was us, we successfully removed ourselves and can continue. If it was some other thread, they will do the work that needs to be done. We can safely sleep until woken. We also remove the test on freezing() from rqst_should_sleep(). Instead we set TASK_FREEZABLE before scheduling. This makes is safe to schedule() when a freeze is pending. As we now loop waiting to be removed from the idle queue, this is a cleaner way to handle freezing. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: discard SP_CONGESTEDNeilBrown
We can tell if a pool is congested by checking if the idle list is empty. We don't need a separate flag. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: add list of idle threadsNeilBrown
Rather than searching a list of threads to find an idle one, having a list of idle threads allows an idle thread to be found immediately. This adds some spin_lock calls which is not ideal, but as the hold-time is tiny it is still faster than searching a list. A future patch will remove them using llist.h. This involves some subtlety and so is left to a separate patch. This removes the need for the RQ_BUSY flag. The rqst is "busy" precisely when it is not on the "idle" list. 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>
2023-10-16SUNRPC: integrate back-channel processing with svc_recv()NeilBrown
Using svc_recv() for (NFSv4.1) back-channel handling means we have just one mechanism for waking threads. Also change kthread_freezable_should_stop() in nfs4_callback_svc() to kthread_should_stop() as used elsewhere. kthread_freezable_should_stop() effectively adds a try_to_freeze() call, and svc_recv() already contains that at an appropriate place. Signed-off-by: NeilBrown <neilb@suse.de> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-10-16SUNRPC: Clean up bc_svc_process()Chuck Lever
The test robot complained that, in some build configurations, the @error variable in bc_svc_process's only caller is set but never used. This happens because dprintk() is the only consumer of that value. - Remove the dprintk() call sites in favor of the svc_process tracepoint - The @error variable and the return value of bc_svc_process() are now unused, so get rid of them. - The @serv parameter is set to rqstp->rq_serv by the only caller, and bc_svc_process() then uses it only to set rqstp->rq_serv. It can be removed. - Rename bc_svc_process() according to the convention that globally-visible RPC server functions have names that begin with "svc_"; and because it is globally-visible, give it a proper kdoc comment. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202308121314.HA8Rq2XG-lkp@intel.com/ Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-09-15SUNRPC: Silence compiler complaints about tautological comparisonsTrond Myklebust
On 64-bit systems, the compiler will complain that the comparison between SIZE_MAX and the 32-bit unsigned int 'len' is unnecessary. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-09-15Revert "SUNRPC: clean up integer overflow check"Anna Schumaker
This reverts commit e87cf8a28e7592bd19064e8181324ae26bc02932. This commit was added to silence a tautological comparison warning, but removing the 'len' value check before calling xdr_inline_decode() is really not what we want. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-31Merge tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "New Features: - Enable the NFS v4.2 READ_PLUS operation by default Stable Fixes: - NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info - NFS: Fix a potential data corruption Bugfixes: - Fix various READ_PLUS issues including: - smatch warnings - xdr size calculations - scratch buffer handling - 32bit / highmem xdr page handling - Fix checkpatch errors in file.c - Fix redundant readdir request after an EOF - Fix handling of COPY ERR_OFFLOAD_NO_REQ - Fix assignment of xprtdata.cred Cleanups: - Remove unused xprtrdma function declarations - Clean up an integer overflow check to avoid a warning - Clean up #includes in dns_resolve.c - Clean up nfs4_get_device_info so we don't pass a NULL pointer to __free_page() - Clean up sunrpc TCP socket timeout configuration - Guard against READDIR loops when entry names are too long - Use EXCHID4_FLAG_USE_PNFS_DS for DS servers" * tag 'nfs-for-6.6-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (22 commits) pNFS: Fix assignment of xprtdata.cred NFSv4.2: fix handling of COPY ERR_OFFLOAD_NO_REQ NFS: Guard against READDIR loop when entry names exceed MAXNAMELEN NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server NFS/pNFS: Set the connect timeout for the pNFS flexfiles driver SUNRPC: Don't override connect timeouts in rpc_clnt_add_xprt() SUNRPC: Allow specification of TCP client connect timeout at setup SUNRPC: Refactor and simplify connect timeout SUNRPC: Set the TCP_SYNCNT to match the socket timeout NFS: Fix a potential data corruption nfs: fix redundant readdir request after get eof nfs/blocklayout: Use the passed in gfp flags filemap: Fix errors in file.c NFSv4/pnfs: minor fix for cleanup path in nfs4_get_device_info NFS: Move common includes outside ifdef SUNRPC: clean up integer overflow check xprtrdma: Remove unused function declaration rpcrdma_bc_post_recv() NFS: Enable the READ_PLUS operation by default SUNRPC: kmap() the xdr pages during decode NFSv4.2: Rework scratch handling for READ_PLUS (again) ...
2023-08-29SUNRPC: Remove unused declaration rpc_modcount()Yue Haibing
These declarations are never implemented since the beginning of git history. Remove these, then merge the two #ifdef block for simplification. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: Remove unused declarationsYue Haibing
Commit c7d7ec8f043e ("SUNRPC: Remove svc_shutdown_net()") removed svc_close_net() implementation but left declaration in place. Remove it. Commit 1f11a034cdc4 ("SUNRPC new transport for the NFSv4.1 shared back channel") removed svc_sock_create()/svc_sock_destroy() but not the declarations. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: Remove return value of svc_pool_wake_idle_thread()NeilBrown
The returned value is not used (any more), so don't return it. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: Count ingress RPC messages per svc_poolChuck Lever
svc_xprt_enqueue() can be costly, since it involves selecting and waking up a process. More than one enqueue is done per incoming RPC. For example, svc_data_ready() enqueues, and so does svc_xprt_receive(). Also, if an RPC message requires more than one call to ->recvfrom() to receive it fully, each one of those calls does an enqueue. To get a sense of the average number of transport enqueue operations needed to process an incoming RPC message, re-use the "packets" pool stat. Track the number of complete RPC messages processed by each thread pool. Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: Deduplicate thread wake-up codeChuck Lever
Refactor: Extract the loop that finds an idle service thread from svc_xprt_enqueue() and svc_wake_up(). Both functions do just about the same thing. Note that svc_wake_up() currently does not hold the RCU read lock while waking the target thread. It indeed should hold the lock, just as svc_xprt_enqueue() does, to ensure the rqstp does not vanish during the wake-up. This patch adds the RCU lock for svc_wake_up(). Note that shrinking the pool thread count is rare, and calls to svc_wake_up() are also quite infrequent. In practice, this race is very unlikely to be hit, so we are not marking the lock fix for stable backport at this time. Reviewed-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: Add enum svc_auth_statusChuck Lever
In addition to the benefits of using an enum rather than a set of macros, we now have a named type that can improve static type checking of function return values. As part of this change, I removed a stale comment from svcauth.h; the return values from current implementations of the auth_ops::release method are all zero/negative errno, not the SVC_OK enum values as the old comment suggested. Suggested-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: change svc_xprt::xpt_flags bits to enumChuck Lever
When a sequence of numbers are needed for internal-use only, an enum is typically best. The sequence will inevitably need to be changed one day, and having an enum means the developer doesn't need to think about renumbering after insertion or deletion. Such patches will be easier to review. Suggested-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: change svc_rqst::rq_flags bits to enumNeilBrown
When a sequence of numbers are needed for internal-use only, an enum is typically best. The sequence will inevitably need to be changed one day, and having an enum means the developer doesn't need to think about renumbering after insertion or deletion. Such patches will be easier to review. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: change svc_pool::sp_flags bits to enumNeilBrown
When a sequence of numbers are needed for internal-use only, an enum is typically best. The sequence will inevitably need to be changed one day, and having an enum means the developer doesn't need to think about renumbering after insertion or deletion. Such patches will be easier to review. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-08-29SUNRPC: change cache_head.flags bits to enumNeilBrown
When a sequence of numbers are needed for internal-use only, an enum is typically best. The sequence will inevitably need to be changed one day, and having an enum means the developer doesn't need to think about renumbering after insertion or deletion. Such patches will be easier to review. Signed-off-by: NeilBrown <neilb@suse.de> 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>
2023-08-29nfsd: 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>