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2023-01-11NFSD: register/unregister of nfsd-client shrinker at nfsd startup/shutdown timeDai Ngo
Currently the nfsd-client shrinker is registered and unregistered at the time the nfsd module is loaded and unloaded. The problem with this is the shrinker is being registered before all of the relevant fields in nfsd_net are initialized when nfsd is started. This can lead to an oops when memory is low and the shrinker is called while nfsd is not running. This patch moves the register/unregister of nfsd-client shrinker from module load/unload time to nfsd startup/shutdown time. Fixes: 44df6f439a17 ("NFSD: add delegation reaper to react to low memory condition") Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-11NFSD: fix use-after-free in nfsd4_ssc_setup_dul()Xingyuan Mo
If signal_pending() returns true, schedule_timeout() will not be executed, causing the waiting task to remain in the wait queue. Fixed by adding a call to finish_wait(), which ensures that the waiting task will always be removed from the wait queue. Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.") Signed-off-by: Xingyuan Mo <hdthky0@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-07NFSD: Use set_bit(RQ_DROPME)Chuck Lever
The premise that "Once an svc thread is scheduled and executing an RPC, no other processes will touch svc_rqst::rq_flags" is false. svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd threads when determining which thread to wake up next. Fixes: 9315564747cb ("NFSD: Use only RQ_DROPME to signal the need to drop a reply") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-06Revert "SUNRPC: Use RMW bitops in single-threaded hot paths"Chuck Lever
The premise that "Once an svc thread is scheduled and executing an RPC, no other processes will touch svc_rqst::rq_flags" is false. svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd threads when determining which thread to wake up next. Found via KCSAN. Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-06nfsd: fix handling of cached open files in nfsd4_open codepathJeff Layton
Commit fb70bf124b05 ("NFSD: Instantiate a struct file when creating a regular NFSv4 file") added the ability to cache an open fd over a compound. There are a couple of problems with the way this currently works: It's racy, as a newly-created nfsd_file can end up with its PENDING bit cleared while the nf is hashed, and the nf_file pointer is still zeroed out. Other tasks can find it in this state and they expect to see a valid nf_file, and can oops if nf_file is NULL. Also, there is no guarantee that we'll end up creating a new nfsd_file if one is already in the hash. If an extant entry is in the hash with a valid nf_file, nfs4_get_vfs_file will clobber its nf_file pointer with the value of op_file and the old nf_file will leak. Fix both issues by making a new nfsd_file_acquirei_opened variant that takes an optional file pointer. If one is present when this is called, we'll take a new reference to it instead of trying to open the file. If the nfsd_file already has a valid nf_file, we'll just ignore the optional file and pass the nfsd_file back as-is. Also rework the tracepoints a bit to allow for an "opened" variant and don't try to avoid counting acquisitions in the case where we already have a cached open file. Fixes: fb70bf124b05 ("NFSD: Instantiate a struct file when creating a regular NFSv4 file") Cc: Trond Myklebust <trondmy@hammerspace.com> Reported-by: Stanislav Saner <ssaner@redhat.com> Reported-and-Tested-by: Ruben Vestergaard <rubenv@drcmr.dk> Reported-and-Tested-by: Torkil Svensgaard <torkil@drcmr.dk> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-01-02nfsd: fix handling of readdir in v4root vs. mount upcall timeoutJeff Layton
If v4 READDIR operation hits a mountpoint and gets back an error, then it will include that entry in the reply and set RDATTR_ERROR for it to the error. That's fine for "normal" exported filesystems, but on the v4root, we need to be more careful to only expose the existence of dentries that lead to exports. If the mountd upcall times out while checking to see whether a mountpoint on the v4root is exported, then we have no recourse other than to fail the whole operation. Cc: Steve Dickson <steved@redhat.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216777 Reported-by: JianHong Yin <yin-jianhong@163.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org>
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>
2022-12-14NFSD: fix use-after-free in __nfs42_ssc_open()Dai Ngo
Problem caused by source's vfsmount being unmounted but remains on the delayed unmount list. This happens when nfs42_ssc_open() return errors. Fixed by removing nfsd4_interssc_connect(), leave the vfsmount for the laundromat to unmount when idle time expires. We don't need to call nfs_do_sb_deactive when nfs42_ssc_open return errors since the file was not opened so nfs_server->active was not incremented. Same as in nfsd4_copy, if we fail to launch nfsd4_do_async_copy thread then there's no need to call nfs_do_sb_deactive Reported-by: Xingyuan Mo <hdthky0@gmail.com> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Tested-by: Xingyuan Mo <hdthky0@gmail.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-12nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failureDan Aloni
On error situation `clp->cl_cb_conn.cb_xprt` should not be given a reference to the xprt otherwise both client cleanup and the error handling path of the caller call to put it. Better to delay handing over the reference to a later branch. [ 72.530665] refcount_t: underflow; use-after-free. [ 72.531933] WARNING: CPU: 0 PID: 173 at lib/refcount.c:28 refcount_warn_saturate+0xcf/0x120 [ 72.533075] Modules linked in: nfsd(OE) nfsv4(OE) nfsv3(OE) nfs(OE) lockd(OE) compat_nfs_ssc(OE) nfs_acl(OE) rpcsec_gss_krb5(OE) auth_rpcgss(OE) rpcrdma(OE) dns_resolver fscache netfs grace rdma_cm iw_cm ib_cm sunrpc(OE) mlx5_ib mlx5_core mlxfw pci_hyperv_intf ib_uverbs ib_core xt_MASQUERADE nf_conntrack_netlink nft_counter xt_addrtype nft_compat br_netfilter bridge stp llc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set overlay nf_tables nfnetlink crct10dif_pclmul crc32_pclmul ghash_clmulni_intel xfs serio_raw virtio_net virtio_blk net_failover failover fuse [last unloaded: sunrpc] [ 72.540389] CPU: 0 PID: 173 Comm: kworker/u16:5 Tainted: G OE 5.15.82-dan #1 [ 72.541511] Hardware name: Red Hat KVM/RHEL-AV, BIOS 1.16.0-3.module+el8.7.0+1084+97b81f61 04/01/2014 [ 72.542717] Workqueue: nfsd4_callbacks nfsd4_run_cb_work [nfsd] [ 72.543575] RIP: 0010:refcount_warn_saturate+0xcf/0x120 [ 72.544299] Code: 55 00 0f 0b 5d e9 01 50 98 00 80 3d 75 9e 39 08 00 0f 85 74 ff ff ff 48 c7 c7 e8 d1 60 8e c6 05 61 9e 39 08 01 e8 f6 51 55 00 <0f> 0b 5d e9 d9 4f 98 00 80 3d 4b 9e 39 08 00 0f 85 4c ff ff ff 48 [ 72.546666] RSP: 0018:ffffb3f841157cf0 EFLAGS: 00010286 [ 72.547393] RAX: 0000000000000026 RBX: ffff89ac6231d478 RCX: 0000000000000000 [ 72.548324] RDX: ffff89adb7c2c2c0 RSI: ffff89adb7c205c0 RDI: ffff89adb7c205c0 [ 72.549271] RBP: ffffb3f841157cf0 R08: 0000000000000000 R09: c0000000ffefffff [ 72.550209] R10: 0000000000000001 R11: ffffb3f841157ad0 R12: ffff89ac6231d180 [ 72.551142] R13: ffff89ac6231d478 R14: ffff89ac40c06180 R15: ffff89ac6231d4b0 [ 72.552089] FS: 0000000000000000(0000) GS:ffff89adb7c00000(0000) knlGS:0000000000000000 [ 72.553175] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 72.553934] CR2: 0000563a310506a8 CR3: 0000000109a66000 CR4: 0000000000350ef0 [ 72.554874] Call Trace: [ 72.555278] <TASK> [ 72.555614] svc_xprt_put+0xaf/0xe0 [sunrpc] [ 72.556276] nfsd4_process_cb_update.isra.11+0xb7/0x410 [nfsd] [ 72.557087] ? update_load_avg+0x82/0x610 [ 72.557652] ? cpuacct_charge+0x60/0x70 [ 72.558212] ? dequeue_entity+0xdb/0x3e0 [ 72.558765] ? queued_spin_unlock+0x9/0x20 [ 72.559358] nfsd4_run_cb_work+0xfc/0x270 [nfsd] [ 72.560031] process_one_work+0x1df/0x390 [ 72.560600] worker_thread+0x37/0x3b0 [ 72.561644] ? process_one_work+0x390/0x390 [ 72.562247] kthread+0x12f/0x150 [ 72.562710] ? set_kthread_struct+0x50/0x50 [ 72.563309] ret_from_fork+0x22/0x30 [ 72.563818] </TASK> [ 72.564189] ---[ end trace 031117b1c72ec616 ]--- [ 72.566019] list_add corruption. next->prev should be prev (ffff89ac4977e538), but was ffff89ac4763e018. (next=ffff89ac4763e018). [ 72.567647] ------------[ cut here ]------------ Fixes: a4abc6b12eb1 ("nfsd: Fix svc_xprt refcnt leak when setup callback client failed") Cc: Xiyu Yang <xiyuyang19@fudan.edu.cn> Cc: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Dan Aloni <dan.aloni@vastdata.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-11nfsd: rework refcounting in filecacheJeff Layton
The filecache refcounting is a bit non-standard for something searchable by RCU, in that we maintain a sentinel reference while it's hashed. This in turn requires that we have to do things differently in the "put" depending on whether its hashed, which we believe to have led to races. There are other problems in here too. nfsd_file_close_inode_sync can end up freeing an nfsd_file while there are still outstanding references to it, and there are a number of subtle ToC/ToU races. Rework the code so that the refcount is what drives the lifecycle. When the refcount goes to zero, then unhash and rcu free the object. A task searching for a nfsd_file is allowed to bump its refcount, but only if it's not already 0. Ensure that we don't make any other changes to it until a reference is held. With this change, the LRU carries a reference. Take special care to deal with it when removing an entry from the list, and ensure that we only repurpose the nf_lru list_head when the refcount is 0 to ensure exclusive access to it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: Avoid clashing function prototypesKees Cook
When built with Control Flow Integrity, function prototypes between caller and function declaration must match. These mismatches are visible at compile time with the new -Wcast-function-type-strict in Clang[1]. There were 97 warnings produced by NFS. For example: fs/nfsd/nfs4xdr.c:2228:17: warning: cast from '__be32 (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, struct nfsd4_access *)') to 'nfsd4_dec' (aka 'unsigned int (*)(struct nfsd4_compoundargs *, void *)') converts to incompatible function type [-Wcast-function-type-strict] [OP_ACCESS] = (nfsd4_dec)nfsd4_decode_access, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The enc/dec callbacks were defined as passing "void *" as the second argument, but were being implicitly cast to a new type. Replace the argument with union nfsd4_op_u, and perform explicit member selection in the function body. There are no resulting binary differences. Changes were made mechanically using the following Coccinelle script, with minor by-hand fixes for members that didn't already match their existing argument name: @find@ identifier func; type T, opsT; identifier ops, N; @@ opsT ops[] = { [N] = (T) func, }; @already_void@ identifier find.func; identifier name; @@ func(..., -void +union nfsd4_op_u *name) { ... } @proto depends on !already_void@ identifier find.func; type T; identifier name; position p; @@ func@p(..., T name ) { ... } @script:python get_member@ type_name << proto.T; member; @@ coccinelle.member = cocci.make_ident(type_name.split("_", 1)[1].split(' ',1)[0]) @convert@ identifier find.func; type proto.T; identifier proto.name; position proto.p; identifier get_member.member; @@ func@p(..., - T name + union nfsd4_op_u *u ) { + T name = &u->member; ... } @cast@ identifier find.func; type T, opsT; identifier ops, N; @@ opsT ops[] = { [N] = - (T) func, }; Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Gustavo A. R. Silva <gustavoars@kernel.org> Cc: linux-nfs@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10SUNRPC: Fix crasher in unwrap_integ_data()Chuck Lever
If a zero length is passed to kmalloc() it returns 0x10, which is not a valid address. gss_verify_mic() subsequently crashes when it attempts to dereference that pointer. Instead of allocating this memory on every call based on an untrusted size value, use a piece of dynamically-allocated scratch memory that is always available. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10SUNRPC: Make the svc_authenticate tracepoint conditionalChuck Lever
Clean up: Simplify the tracepoint's only call site. Also, I noticed that when svc_authenticate() returns SVC_COMPLETE, it leaves rq_auth_stat set to an error value. That doesn't need to be recorded in the trace log. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
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>
2022-12-10SUNRPC: Clean up xdr_write_pages()Chuck Lever
Make it more evident how xdr_write_pages() updates the tail buffer by using the convention of naming the iov pointer variable "tail". I spent more than a couple of hours chasing through code to understand this, so someone is likely to find this useful later. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10SUNRPC: Don't leak netobj memory when gss_read_proxy_verf() failsChuck Lever
Fixes: 030d794bf498 ("SUNRPC: Use gssproxy upcall for server RPCGSS authentication.") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Cc: <stable@vger.kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10NFSD: add CB_RECALL_ANY tracepointsDai Ngo
Add tracepoints to trace start and end of CB_RECALL_ANY operation. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> [ cel: added show_rca_mask() macro ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: add delegation reaper to react to low memory conditionDai Ngo
The delegation reaper is called by nfsd memory shrinker's on the 'count' callback. It scans the client list and sends the courtesy CB_RECALL_ANY to the clients that hold delegations. To avoid flooding the clients with CB_RECALL_ANY requests, the delegation reaper sends only one CB_RECALL_ANY request to each client per 5 seconds. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> [ cel: moved definition of RCA4_TYPE_MASK_RDATA_DLG ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: add support for sending CB_RECALL_ANYDai Ngo
Add XDR encode and decode function for CB_RECALL_ANY. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: refactoring courtesy_client_reaper to a generic low memory shrinkerDai Ngo
Refactoring courtesy_client_reaper to generic low memory shrinker so it can be used for other purposes. Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10trace: Relocate event helper filesChuck Lever
Steven Rostedt says: > The include/trace/events/ directory should only hold files that > are to create events, not headers that hold helper functions. > > Can you please move them out of include/trace/events/ as that > directory is "special" in the creation of events. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Leon Romanovsky <leonro@nvidia.com> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2022-12-10NFSD: pass range end to vfs_fsync_range() instead of countBrian Foster
_nfsd_copy_file_range() calls vfs_fsync_range() with an offset and count (bytes written), but the former wants the start and end bytes of the range to sync. Fix it up. Fixes: eac0b17a77fb ("NFSD add vfs_fsync after async copy is done") Signed-off-by: Brian Foster <bfoster@redhat.com> Tested-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10lockd: fix file selection in nlmsvc_cancel_blockedJeff Layton
We currently do a lock_to_openmode call based on the arguments from the NLM_UNLOCK call, but that will always set the fl_type of the lock to F_UNLCK, and the O_RDONLY descriptor is always chosen. Fix it to use the file_lock from the block instead. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10lockd: ensure we use the correct file descriptor when unlockingJeff Layton
Shared locks are set on O_RDONLY descriptors and exclusive locks are set on O_WRONLY ones. nlmsvc_unlock however calls vfs_lock_file twice, once for each descriptor, but it doesn't reset fl_file. Ensure that it does. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10lockd: set missing fl_flags field when retrieving argsJeff Layton
Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: Use struct_size() helper in alloc_session()Xiu Jianfeng
Use struct_size() helper to simplify the code, no functional changes. Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10nfsd: return error if nfs4_setacl failsJeff Layton
With the addition of POSIX ACLs to struct nfsd_attrs, we no longer return an error if setting the ACL fails. Ensure we return the na_aclerr error on SETATTR if there is one. Fixes: c0cbe70742f4 ("NFSD: add posix ACLs to struct nfsd_attrs") Cc: Neil Brown <neilb@suse.de> Reported-by: Yongcheng Yang <yoyang@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10lockd: set other missing fields when unlocking filesTrond Myklebust
vfs_lock_file() expects the struct file_lock to be fully initialised by the caller. Re-exported NFSv3 has been seen to Oops if the fl_file field is NULL. Fixes: aec158242b87 ("lockd: set fl_owner when unlocking files") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216582 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10NFSD: Add an nfsd_file_fsync tracepointChuck Lever
Add a tracepoint to capture the number of filecache-triggered fsync calls and which files needed it. Also, record when an fsync triggers a write verifier reset. Examples: <...>-97 [007] 262.505611: nfsd_file_free: inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400 <...>-97 [007] 262.505612: nfsd_file_fsync: inode=0xffff888171e08140 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d2400 ret=0 <...>-97 [007] 262.505623: nfsd_file_free: inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00 <...>-97 [007] 262.505624: nfsd_file_fsync: inode=0xffff888171e08dc0 ref=0 flags=GC may=WRITE nf_file=0xffff8881373d1e00 ret=0 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-12-10sunrpc: svc: Remove an unused static function svc_ungetu32()Li zeming
The svc_ungetu32 function is not used, you could remove it. Signed-off-by: Li zeming <zeming@nfschina.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-12-10nfsd: fix up the filecache laundrette schedulingJeff Layton
We don't really care whether there are hashed entries when it comes to scheduling the laundrette. They might all be non-gc entries, after all. We only want to schedule it if there are entries on the LRU. Switch to using list_lru_count, and move the check into nfsd_file_gc_worker. The other callsite in nfsd_file_put doesn't need to count entries, since it only schedules the laundrette after adding an entry to the LRU. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28nfsd: reorganize filecache.cJeff Layton
In a coming patch, we're going to rework how the filecache refcounting works. Move some code around in the function to reduce the churn in the later patches, and rename some of the functions with (hopefully) clearer names: nfsd_file_flush becomes nfsd_file_fsync, and nfsd_file_unhash_and_dispose is renamed to nfsd_file_unhash_and_queue. Also, the nfsd_file_put_final tracepoint is renamed to nfsd_file_free, to better match the name of the function from which it's called. Signed-off-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28nfsd: remove the pages_flushed statistic from filecacheJeff Layton
We're counting mapping->nrpages, but not all of those are necessarily dirty. We don't really have a simple way to count just the dirty pages, so just remove this stat since it's not accurate. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-11-28MAINTAINERS: NFSD should be responsible for fs/exportfsChuck Lever
We recently received a patch for fs/exportfs/expfs.c, but there isn't a subsystem maintainer listed for fs/exportfs: Christian Brauner <brauner@kernel.org> (commit_signer:2/2=100%,authored:1/2=50%,added_lines:3/6=50%,removed_lines:2/6=33%) Al Viro <viro@zeniv.linux.org.uk> (commit_signer:1/2=50%,authored:1/2=50%,added_lines:3/6=50%,removed_lines:4/6=67%) Miklos Szeredi <mszeredi@redhat.com> (commit_signer:1/2=50%) Amir Goldstein <amir73il@gmail.com> (commit_signer:1/2=50%) linux-kernel@vger.kernel.org (open list) Neil says: > Looking at recent commits, patches come in through multiple > different trees. > nfsd certainly has an interest in expfs.c. The only other user is > name_to_handle/open_by_handle API. > I see it as primarily nfsd functionality which is useful enough to > be exported directly to user-space. > (It was created by me when I was nfsd maintainer - does that > count?) Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Acked-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Fix licensing header in filecache.cChuck Lever
Add a missing SPDX header. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Use rhashtable for managing nfs4_file objectsChuck Lever
fh_match() is costly, especially when filehandles are large (as is the case for NFSv4). It needs to be used sparingly when searching data structures. Unfortunately, with common workloads, I see multiple thousands of objects stored in file_hashtbl[], which has just 256 buckets, making its bucket hash chains quite lengthy. Walking long hash chains with the state_lock held blocks other activity that needs that lock. Sizable hash chains are a common occurrance once the server has handed out some delegations, for example -- IIUC, each delegated file is held open on the server by an nfs4_file object. To help mitigate the cost of searching with fh_match(), replace the nfs4_file hash table with an rhashtable, which can dynamically resize its bucket array to minimize hash chain length. The result of this modification is an improvement in the latency of NFSv4 operations, and the reduction of nfsd CPU utilization due to eliminating the cost of multiple calls to fh_match() and reducing the CPU cache misses incurred while walking long hash chains in the nfs4_file hash table. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Refactor find_file()Chuck Lever
find_file() is now the only caller of find_file_locked(), so just fold these two together. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Clean up find_or_add_file()Chuck Lever
Remove the call to find_file_locked() in insert_nfs4_file(). Tracing shows that over 99% of these calls return NULL. Thus it is not worth the expense of the extra bucket list traversal. insert_file() already deals correctly with the case where the item is already in the hash bucket. Since nfsd4_file_hash_insert() is now just a wrapper around insert_file(), move the meat of insert_file() into nfsd4_file_hash_insert() and get rid of it. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28NFSD: Add a nfsd4_file_hash_remove() helperChuck Lever
Refactor to relocate hash deletion operation to a helper function that is close to most other nfs4_file data structure operations. The "noinline" annotation will become useful in a moment when the hlist_del_rcu() is replaced with a more complex rhash remove operation. It also guarantees that hash remove operations can be traced with "-p function -l remove_nfs4_file_locked". This also simplifies the organization of forward declarations: the to-be-added rhashtable and its param structure will be defined /after/ put_nfs4_file(). Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Clean up nfsd4_init_file()Chuck Lever
Name this function more consistently. I'm going to use nfsd4_file_ and nfsd4_file_hash_ for these helpers. Change the @fh parameter to be const pointer for better type safety. Finally, move the hash insertion operation to the caller. This is typical for most other "init_object" type helpers, and it is where most of the other nfs4_file hash table operations are located. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Update file_hashtbl() helpersChuck Lever
Enable callers to use const pointers for type safety. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Use const pointers as parameters to fh_ helpersChuck Lever
Enable callers to use const pointers where they are able to. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28NFSD: Trace delegation revocationsChuck Lever
Delegation revocation is an exceptional event that is not otherwise visible externally (eg, no network traffic is emitted). Generate a trace record when it occurs so that revocation can be observed or other activity can be triggered. Example: nfsd-1104 [005] 1912.002544: nfsd_stid_revoke: client 633c9343:4e82788d stateid 00000003:00000001 ref=2 type=DELEG Trace infrastructure is provided for subsequent additional tracing related to nfs4_stid activity. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Trace stateids returned via DELEGRETURNChuck Lever
Handing out a delegation stateid is recorded with the nfsd_deleg_read tracepoint, but there isn't a matching tracepoint for recording when the stateid is returned. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Clean up nfs4_preprocess_stateid_op() call sitesChuck Lever
Remove the lame-duck dprintk()s around nfs4_preprocess_stateid_op() call sites. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28NFSD: Flesh out a documenting comment for filecache.cChuck Lever
Record what we've learned recently about the NFSD filecache in a documenting comment so our future selves don't forget what all this is for. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Add an NFSD_FILE_GC flag to enable nfsd_file garbage collectionChuck Lever
NFSv4 operations manage the lifetime of nfsd_file items they use by means of NFSv4 OPEN and CLOSE. Hence there's no need for them to be garbage collected. Introduce a mechanism to enable garbage collection for nfsd_file items used only by NFSv2/3 callers. Note that the change in nfsd_file_put() ensures that both CLOSE and DELEGRETURN will actually close out and free an nfsd_file on last reference of a non-garbage-collected file. Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=394 Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-11-28NFSD: Revert "NFSD: NFSv4 CLOSE should release an nfsd_file immediately"Chuck Lever
This reverts commit 5e138c4a750dc140d881dab4a8804b094bbc08d2. That commit attempted to make files available to other users as soon as all NFSv4 clients were done with them, rather than waiting until the filecache LRU had garbage collected them. It gets the reference counting wrong, for one thing. But it also misses that DELEGRETURN should release a file in the same fashion. In fact, any nfsd_file_put() on an file held open by an NFSv4 client needs potentially to release the file immediately... Clear the way for implementing that idea. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28NFSD: Pass the target nfsd_file to nfsd_commit()Chuck Lever
In a moment I'm going to introduce separate nfsd_file types, one of which is garbage-collected; the other, not. The garbage-collected variety is to be used by NFSv2 and v3, and the non-garbage-collected variety is to be used by NFSv4. nfsd_commit() is invoked by both NFSv3 and NFSv4 consumers. We want nfsd_commit() to find and use the correct variety of cached nfsd_file object for the NFS version that is in use. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de>
2022-11-28nfsd: don't call nfsd_file_put from client states seqfile displayJeff Layton
We had a report of this: BUG: sleeping function called from invalid context at fs/nfsd/filecache.c:440 ...with a stack trace showing nfsd_file_put being called from nfs4_show_open. This code has always tried to call fput while holding a spinlock, but we recently changed this to use the filecache, and that started triggering the might_sleep() in nfsd_file_put. states_start takes and holds the cl_lock while iterating over the client's states, and we can't sleep with that held. Have the various nfs4_show_* functions instead hold the fi_lock instead of taking a nfsd_file reference. Fixes: 78599c42ae3c ("nfsd4: add file to display list of client's opens") Link: https://bugzilla.redhat.com/show_bug.cgi?id=2138357 Reported-by: Zhi Li <yieli@redhat.com> Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>