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2024-11-18NFSD: Fix nfsd4_shutdown_copy()Chuck Lever
nfsd4_shutdown_copy() is just this: while ((copy = nfsd4_get_copy(clp)) != NULL) nfsd4_stop_copy(copy); nfsd4_get_copy() bumps @copy's reference count, preventing nfsd4_stop_copy() from releasing @copy. A while loop like this usually works by removing the first element of the list, but neither nfsd4_get_copy() nor nfsd4_stop_copy() alters the async_copies list. Best I can tell, then, is that nfsd4_shutdown_copy() continues to loop until other threads manage to remove all the items from this list. The spinning loop blocks shutdown until these items are gone. Possibly the reason we haven't seen this issue in the field is because client_has_state() prevents __destroy_client() from calling nfsd4_shutdown_copy() if there are any items on this list. In a subsequent patch I plan to remove that restriction. Fixes: e0639dc5805a ("NFSD introduce async copy feature") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Add a tracepoint to record canceled async COPY operationsChuck Lever
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make nfsd4_session->se_flags a boolJeff Layton
While this holds the flags from the CREATE_SESSION request, nothing ever consults them. The only flag used is NFS4_SESSION_DEAD. Make it a simple bool instead. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: remove nfsd4_session->se_bchannelJeff Layton
This field is written and is never consulted again. Remove it. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make use of warning provided by refcount_tNeilBrown
refcount_t, by design, checks for unwanted situations and provides warnings. It is rarely useful to have explicit warnings with refcount usage. In this case we have an explicit warning if a refcount_t reaches zero when decremented. Simply using refcount_dec() will provide a similar warning and also mark the refcount_t as saturated to avoid any possible use-after-free. This patch drops the warning and uses refcount_dec() instead of refcount_dec_and_test(). Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Don't fail OP_SETCLIENTID when there are too many clients.NeilBrown
Failing OP_SETCLIENTID or OP_EXCHANGE_ID should only happen if there is memory allocation failure. Putting a hard limit on the number of clients is not really helpful as it will either happen too early and prevent clients that the server can easily handle, or too late and allow clients when the server is swamped. The calculated limit is still useful for expiring courtesy clients where there are "too many" clients, but it shouldn't prevent the creation of active clients. Testing of lots of clients against small-mem servers reports repeated NFS4ERR_DELAY responses which doesn't seem helpful. There may have been reports of similar problems in production use. Also remove an outdated comment - we do use a slab cache. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: release svc_expkey/svc_export with rcu_workYang Erkun
The last reference for `cache_head` can be reduced to zero in `c_show` and `e_show`(using `rcu_read_lock` and `rcu_read_unlock`). Consequently, `svc_export_put` and `expkey_put` will be invoked, leading to two issues: 1. The `svc_export_put` will directly free ex_uuid. However, `e_show`/`c_show` will access `ex_uuid` after `cache_put`, which can trigger a use-after-free issue, shown below. ================================================================== BUG: KASAN: slab-use-after-free in svc_export_show+0x362/0x430 [nfsd] Read of size 1 at addr ff11000010fdc120 by task cat/870 CPU: 1 UID: 0 PID: 870 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x53/0x70 print_address_description.constprop.0+0x2c/0x3a0 print_report+0xb9/0x280 kasan_report+0xae/0xe0 svc_export_show+0x362/0x430 [nfsd] c_show+0x161/0x390 [sunrpc] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 proc_reg_read+0xe1/0x140 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Allocated by task 830: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 __kmalloc_node_track_caller_noprof+0x1bc/0x400 kmemdup_noprof+0x22/0x50 svc_export_parse+0x8a9/0xb80 [nfsd] cache_do_downcall+0x71/0xa0 [sunrpc] cache_write_procfs+0x8e/0xd0 [sunrpc] proc_reg_write+0xe1/0x140 vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 868: kasan_save_stack+0x20/0x40 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x37/0x50 kfree+0xf3/0x3e0 svc_export_put+0x87/0xb0 [nfsd] cache_purge+0x17f/0x1f0 [sunrpc] nfsd_destroy_serv+0x226/0x2d0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e 2. We cannot sleep while using `rcu_read_lock`/`rcu_read_unlock`. However, `svc_export_put`/`expkey_put` will call path_put, which subsequently triggers a sleeping operation due to the following `dput`. ============================= WARNING: suspicious RCU usage 5.10.0-dirty #141 Not tainted ----------------------------- ... Call Trace: dump_stack+0x9a/0xd0 ___might_sleep+0x231/0x240 dput+0x39/0x600 path_put+0x1b/0x30 svc_export_put+0x17/0x80 e_show+0x1c9/0x200 seq_read_iter+0x63f/0x7c0 seq_read+0x226/0x2d0 vfs_read+0x113/0x2c0 ksys_read+0xc9/0x170 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Fix these issues by using `rcu_work` to help release `svc_expkey`/`svc_export`. This approach allows for an asynchronous context to invoke `path_put` and also facilitates the freeing of `uuid/exp/key` after an RCU grace period. Fixes: 9ceddd9da134 ("knfsd: Allow lockless lookups of the exports") Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: make sure exp active before svc_export_showYang Erkun
The function `e_show` was called with protection from RCU. This only ensures that `exp` will not be freed. Therefore, the reference count for `exp` can drop to zero, which will trigger a refcount use-after-free warning when `exp_get` is called. To resolve this issue, use `cache_get_rcu` to ensure that `exp` remains active. ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 819 at lib/refcount.c:25 refcount_warn_saturate+0xb1/0x120 CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb1/0x120 ... Call Trace: <TASK> e_show+0x20b/0x230 [nfsd] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fixes: bf18f163e89c ("NFSD: Using exp_get for export getting") Cc: stable@vger.kernel.org # 4.20+ Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Cap the number of bytes copied by nfs4_reset_recoverydir()Chuck Lever
It's only current caller already length-checks the string, but let's be safe. Fixes: 0964a3d3f1aa ("[PATCH] knfsd: nfsd4 reboot dirname fix") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove unused values from nfsd4_encode_components_esc()Chuck Lever
Clean up. The computed value of @p is saved each time through the loop but is never used. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove unused results in nfsd4_encode_pathname4()Chuck Lever
Clean up. The result of "*p++" is saved, but is not used before it is overwritten. The result of xdr_encode_opaque() is saved each time through the loop but is never used. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Prevent NULL dereference in nfsd4_process_cb_update()Chuck Lever
@ses is initialized to NULL. If __nfsd4_find_backchannel() finds no available backchannel session, setup_callback_client() will try to dereference @ses and segfault. Fixes: dcbeaa68dbbd ("nfsd4: allow backchannel recovery") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove a never-true comparisonChuck Lever
fh_size is an unsigned int, thus it can never be less than 0. Fixes: d8b26071e65e ("NFSD: simplify struct nfsfh") Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Remove dead code in nfsd4_create_session()Chuck Lever
Clean up. AFAICT, there is no way to reach the out_free_conn label with @old set to a non-NULL value, so the expire_client(old) call is never reached and can be removed. Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: refine and rename NFSD_MAY_LOCKNeilBrown
NFSD_MAY_LOCK means a few different things. - it means that GSS is not required. - it means that with NFSEXP_NOAUTHNLM, authentication is not required - it means that OWNER_OVERRIDE is allowed. None of these are specific to locking, they are specific to the NLM protocol. So: - rename to NFSD_MAY_NLM - set NFSD_MAY_OWNER_OVERRIDE and NFSD_MAY_BYPASS_GSS in nlm_fopen() so that NFSD_MAY_NLM doesn't need to imply these. - move the test on NFSEXP_NOAUTHNLM out of nfsd_permission() and into fh_verify where other special-case tests on the MAY flags happen. nfsd_permission() can be called from other places than fh_verify(), but none of these will have NFSD_MAY_NLM. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18NFSD: Replace use of NFSD_MAY_LOCK in nfsd4_lock()Chuck Lever
NFSv4 LOCK operations should not avoid the set of authorization checks that apply to all other NFSv4 operations. Also, the "no_auth_nlm" export option should apply only to NLM LOCK requests. It's not necessary or sensible to apply it to NFSv4 LOCK operations. Instead, set no permission bits when calling fh_verify(). Subsequent stateid processing handles authorization checks. Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: replace call_rcu by kfree_rcu for simple kmem_cache_free callbackJulia Lawall
Since SLOB was removed and since commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"), it is not necessary to use call_rcu when the callback only performs kmem_cache_free. Use kfree_rcu() directly. The changes were made using Coccinelle. Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr> Reviewed-by: Jeff Layton <jlayton@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Fix NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOTPali Rohár
Currently NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT do not bypass only GSS, but bypass any method. This is a problem specially for NFS3 AUTH_NULL-only exports. The purpose of NFSD_MAY_BYPASS_GSS_ON_ROOT is described in RFC 2623, section 2.3.2, to allow mounting NFS2/3 GSS-only export without authentication. So few procedures which do not expose security risk used during mount time can be called also with AUTH_NONE or AUTH_SYS, to allow client mount operation to finish successfully. The problem with current implementation is that for AUTH_NULL-only exports, the NFSD_MAY_BYPASS_GSS_ON_ROOT is active also for NFS3 AUTH_UNIX mount attempts which confuse NFS3 clients, and make them think that AUTH_UNIX is enabled and is working. Linux NFS3 client never switches from AUTH_UNIX to AUTH_NONE on active mount, which makes the mount inaccessible. Fix the NFSD_MAY_BYPASS_GSS and NFSD_MAY_BYPASS_GSS_ON_ROOT implementation and really allow to bypass only exports which have enabled some real authentication (GSS, TLS, or any other). The result would be: For AUTH_NULL-only export if client attempts to do mount with AUTH_UNIX flavor then it will receive access errors, which instruct client that AUTH_UNIX flavor is not usable and will either try other auth flavor (AUTH_NULL if enabled) or fails mount procedure. Similarly if client attempt to do mount with AUTH_NULL flavor and only AUTH_UNIX flavor is enabled then the client will receive access error. This should fix problems with AUTH_NULL-only or AUTH_UNIX-only exports if client attempts to mount it with other auth flavor (e.g. with AUTH_NULL for AUTH_UNIX-only export, or with AUTH_UNIX for AUTH_NULL-only export). Signed-off-by: Pali Rohár <pali@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: Fill NFSv4.1 server implementation fields in OP_EXCHANGE_ID responsePali Rohár
NFSv4.1 OP_EXCHANGE_ID response from server may contain server implementation details (domain, name and build time) in optional nfs_impl_id4 field. Currently nfsd does not fill this field. Send these information in NFSv4.1 OP_EXCHANGE_ID response. Fill them with the same values as what is Linux NFSv4.1 client doing. Domain is hardcoded to "kernel.org", name is composed in the same way as "uname -srvm" output and build time is hardcoded to zeros. NFSv4.1 client and server implementation fields are useful for statistic purposes or for identifying type of clients and servers. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18nfsd: new tracepoint for after op_func in compound processingJeff Layton
Turn nfsd_compound_encode_err tracepoint into a class and add a new nfsd_compound_op_err tracepoint. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-18Merge tag 'vfs-6.13.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Fixup and improve NLM and kNFSD file lock callbacks Last year both GFS2 and OCFS2 had some work done to make their locking more robust when exported over NFS. Unfortunately, part of that work caused both NLM (for NFS v3 exports) and kNFSD (for NFSv4.1+ exports) to no longer send lock notifications to clients This in itself is not a huge problem because most NFS clients will still poll the server in order to acquire a conflicted lock It's important for NLM and kNFSD that they do not block their kernel threads inside filesystem's file_lock implementations because that can produce deadlocks. We used to make sure of this by only trusting that posix_lock_file() can correctly handle blocking lock calls asynchronously, so the lock managers would only setup their file_lock requests for async callbacks if the filesystem did not define its own lock() file operation However, when GFS2 and OCFS2 grew the capability to correctly handle blocking lock requests asynchronously, they started signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check for also trusting posix_lock_file() was inadvertently dropped, so now most filesystems no longer produce lock notifications when exported over NFS Fix this by using an fop_flag which greatly simplifies the problem and grooms the way for future uses by both filesystems and lock managers alike - Add a sysctl to delete the dentry when a file is removed instead of making it a negative dentry Commit 681ce8623567 ("vfs: Delete the associated dentry when deleting a file") introduced an unconditional deletion of the associated dentry when a file is removed. However, this led to performance regressions in specific benchmarks, such as ilebench.sum_operations/s, prompting a revert in commit 4a4be1ad3a6e ("Revert "vfs: Delete the associated dentry when deleting a file""). This reintroduces the concept conditionally through a sysctl - Expand the statmount() system call: * Report the filesystem subtype in a new fs_subtype field to e.g., report fuse filesystem subtypes * Report the superblock source in a new sb_source field * Add a new way to return filesystem specific mount options in an option array that returns filesystem specific mount options separated by zero bytes and unescaped. This allows caller's to retrieve filesystem specific mount options and immediately pass them to e.g., fsconfig() without having to unescape or split them * Report security (LSM) specific mount options in a separate security option array. We don't lump them together with filesystem specific mount options as security mount options are generic and most users aren't interested in them The format is the same as for the filesystem specific mount option array - Support relative paths in fsconfig()'s FSCONFIG_SET_STRING command - Optimize acl_permission_check() to avoid costly {g,u}id ownership checks if possible - Use smp_mb__after_spinlock() to avoid full smp_mb() in evict() - Add synchronous wakeup support for ep_poll_callback. Currently, epoll only uses wake_up() to wake up task. But sometimes there are epoll users which want to use the synchronous wakeup flag to give a hint to the scheduler, e.g., the Android binder driver. So add a wake_up_sync() define, and use wake_up_sync() when sync is true in ep_poll_callback() Fixes: - Fix kernel documentation for inode_insert5() and iget5_locked() - Annotate racy epoll check on file->f_ep - Make F_DUPFD_QUERY associative - Avoid filename buffer overrun in initramfs - Don't let statmount() return empty strings - Add a cond_resched() to dump_user_range() to avoid hogging the CPU - Don't query the device logical blocksize multiple times for hfsplus - Make filemap_read() check that the offset is positive or zero Cleanups: - Various typo fixes - Cleanup wbc_attach_fdatawrite_inode() - Add __releases annotation to wbc_attach_and_unlock_inode() - Add hugetlbfs tracepoints - Fix various vfs kernel doc parameters - Remove obsolete TODO comment from io_cancel() - Convert wbc_account_cgroup_owner() to take a folio - Fix comments for BANDWITH_INTERVAL and wb_domain_writeout_add() - Reorder struct posix_acl to save 8 bytes - Annotate struct posix_acl with __counted_by() - Replace one-element array with flexible array member in freevxfs - Use idiomatic atomic64_inc_return() in alloc_mnt_ns()" * tag 'vfs-6.13.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits) statmount: retrieve security mount options vfs: make evict() use smp_mb__after_spinlock instead of smp_mb statmount: add flag to retrieve unescaped options fs: add the ability for statmount() to report the sb_source writeback: wbc_attach_fdatawrite_inode out of line writeback: add a __releases annoation to wbc_attach_and_unlock_inode fs: add the ability for statmount() to report the fs_subtype fs: don't let statmount return empty strings fs:aio: Remove TODO comment suggesting hash or array usage in io_cancel() hfsplus: don't query the device logical block size multiple times freevxfs: Replace one-element array with flexible array member fs: optimize acl_permission_check() initramfs: avoid filename buffer overrun fs/writeback: convert wbc_account_cgroup_owner to take a folio acl: Annotate struct posix_acl with __counted_by() acl: Realign struct posix_acl to save 8 bytes epoll: Add synchronous wakeup support for ep_poll_callback coredump: add cond_resched() to dump_user_range mm/page-writeback.c: Fix comment of wb_domain_writeout_add() mm/page-writeback.c: Update comment for BANDWIDTH_INTERVAL ...
2024-11-11mm/list_lru: simplify the list_lru walk callback functionKairui Song
Now isolation no longer takes the list_lru global node lock, only use the per-cgroup lock instead. And this lock is inside the list_lru_one being walked, no longer needed to pass the lock explicitly. Link: https://lkml.kernel.org/r/20241104175257.60853-7-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-11nfsd: have nfsd4_deleg_getattr_conflict pass back write deleg pointerJeff Layton
Currently we pass back the size and whether it has been modified, but those just mirror values tracked inside the delegation. In a later patch, we'll need to get at the timestamps in the delegation too, so just pass back a reference to the write delegation, and use that to properly override values in the iattr. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop the nfsd4_fattr_args "size" fieldJeff Layton
We already have a slot for this in the kstat structure. Just overwrite that instead of keeping a copy. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop the ncf_cb_bmap fieldJeff Layton
This is always the same value, and in a later patch we're going to need to set bits in WORD2. We can simplify this code and save a little space in the delegation too. Just hardcode the bitmap in the callback encode function. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11nfsd: drop inode parameter from nfsd4_change_attribute()Jeff Layton
The inode that nfs4_open_delegation() passes to this function is wrong, which throws off the result. The inode will end up getting a directory-style change attr instead of a regular-file-style one. Fix up nfs4_delegation_stat() to fetch STATX_MODE, and then drop the inode parameter from nfsd4_change_attribute(), since it's no longer needed. Fixes: c5967721e106 ("NFSD: handle GETATTR conflict with write delegation") Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11NFSD: Remove unused function parameterChuck Lever
Clean up: Commit 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd") moved the fh_verify() call site out of nfsd_open(). That was the only user of nfsd_open's @rqstp parameter, so that parameter can be removed. Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11NFSD: Remove unnecessary posix_acl_entry pointer initializationThorsten Blum
The posix_acl_entry pointer pe is already initialized by the FOREACH_ACL_ENTRY() macro. Remove the unnecessary initialization. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-11NFSD: Prevent a potential integer overflowChuck Lever
If the tag length is >= U32_MAX - 3 then the "length + 4" addition can result in an integer overflow. Address this by splitting the decoding into several steps so that decode_cb_compound4res() does not have to perform arithmetic on the unsafe length value. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-09Merge tag 'nfsd-6.12-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fix from Chuck Lever: - Fix a v6.12-rc regression when exporting ext4 filesystems with NFSD * tag 'nfsd-6.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: NFSD: Fix READDIR on NFSv3 mounts of ext4 exports
2024-11-07NFSD: Fix READDIR on NFSv3 mounts of ext4 exportsChuck Lever
I noticed that recently, simple operations like "make" started failing on NFSv3 mounts of ext4 exports. Network capture shows that READDIRPLUS operated correctly but READDIR failed with NFS3ERR_INVAL. The vfs_llseek() call returned EINVAL when it is passed a non-zero starting directory cookie. I bisected to commit c689bdd3bffa ("nfsd: further centralize protocol version checks."). Turns out that nfsd3_proc_readdir() does not call fh_verify() before it calls nfsd_readdir(), so the new fhp->fh_64bit_cookies boolean is not set properly. This leaves the NFSD_MAY_64BIT_COOKIE unset when the directory is opened. For ext4, this causes the wrong "max file size" value to be used when sanity checking the incoming directory cookie (which is a seek offset value). The fhp->fh_64bit_cookies boolean is /always/ properly initialized after nfsd_open() returns. There doesn't seem to be a reason for the generic NFSD open helper to handle the f_mode fix-up for directories, so just move that to the one caller that tries to open an S_IFDIR with NFSD_MAY_64BIT_COOKIE. Suggested-by: NeilBrown <neilb@suse.de> Fixes: c689bdd3bffa ("nfsd: further centralize protocol version checks.") Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-11-02Merge tag 'nfsd-6.12-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Fix two async COPY bugs found during NFS bake-a-thon - Fix an svcrdma memory leak * tag 'nfsd-6.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: rpcrdma: Always release the rpcrdma_device's xa_array NFSD: Never decrement pending_async_copies on error NFSD: Initialize struct nfsd4_copy earlier
2024-10-30NFSD: Never decrement pending_async_copies on errorChuck Lever
The error flow in nfsd4_copy() calls cleanup_async_copy(), which already decrements nn->pending_async_copies. Reported-by: Olga Kornievskaia <okorniev@redhat.com> Fixes: aadc3bbea163 ("NFSD: Limit the number of concurrent async COPY operations") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-29NFSD: Initialize struct nfsd4_copy earlierChuck Lever
Ensure the refcount and async_copies fields are initialized early. cleanup_async_copy() will reference these fields if an error occurs in nfsd4_copy(). If they are not correctly initialized, at the very least, a refcount underflow occurs. Reported-by: Olga Kornievskaia <okorniev@redhat.com> Fixes: aadc3bbea163 ("NFSD: Limit the number of concurrent async COPY operations") Reviewed-by: Jeff Layton <jlayton@kernel.org> Tested-by: Olga Kornievskaia <okorniev@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-25Merge tag 'nfsd-6.12-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Fix a couple of use-after-free bugs * tag 'nfsd-6.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net nfsd: fix race between laundromat and free_stateid
2024-10-21nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_netYang Erkun
In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the function `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will release all resources related to the hashed `nfs4_client`. If the `nfsd_client_shrinker` is running concurrently, the `expire_client` function will first unhash this client and then destroy it. This can lead to the following warning. Additionally, numerous use-after-free errors may occur as well. nfsd_client_shrinker echo 0 > /proc/fs/nfsd/threads expire_client nfsd_shutdown_net unhash_client ... nfs4_state_shutdown_net /* won't wait shrinker exit */ /* cancel_work(&nn->nfsd_shrinker_work) * nfsd_file for this /* won't destroy unhashed client1 */ * client1 still alive nfs4_state_destroy_net */ nfsd_file_cache_shutdown /* trigger warning */ kmem_cache_destroy(nfsd_file_slab) kmem_cache_destroy(nfsd_file_mark_slab) /* release nfsd_file and mark */ __destroy_client ==================================================================== BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on __kmem_cache_shutdown() -------------------------------------------------------------------- CPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1 dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xac/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e ==================================================================== BUG nfsd_file_mark (Tainted: G B W ): Objects remaining nfsd_file_mark on __kmem_cache_shutdown() -------------------------------------------------------------------- dump_stack_lvl+0x53/0x70 slab_err+0xb0/0xf0 __kmem_cache_shutdown+0x15c/0x310 kmem_cache_destroy+0x66/0x160 nfsd_file_cache_shutdown+0xc8/0x210 [nfsd] nfsd_destroy_serv+0x251/0x2a0 [nfsd] nfsd_svc+0x125/0x1e0 [nfsd] write_threads+0x16a/0x2a0 [nfsd] nfsctl_transaction_write+0x74/0xa0 [nfsd] vfs_write+0x1a5/0x6d0 ksys_write+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e To resolve this issue, cancel `nfsd_shrinker_work` using synchronous mode in nfs4_state_shutdown_net. Fixes: 7c24fa225081 ("NFSD: replace delayed_work with work_struct for nfsd_client_shrinker") Signed-off-by: Yang Erkun <yangerkun@huaweicloud.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-18nfsd: fix race between laundromat and free_stateidOlga Kornievskaia
There is a race between laundromat handling of revoked delegations and a client sending free_stateid operation. Laundromat thread finds that delegation has expired and needs to be revoked so it marks the delegation stid revoked and it puts it on a reaper list but then it unlock the state lock and the actual delegation revocation happens without the lock. Once the stid is marked revoked a racing free_stateid processing thread does the following (1) it calls list_del_init() which removes it from the reaper list and (2) frees the delegation stid structure. The laundromat thread ends up not calling the revoke_delegation() function for this particular delegation but that means it will no release the lock lease that exists on the file. Now, a new open for this file comes in and ends up finding that lease list isn't empty and calls nfsd_breaker_owns_lease() which ends up trying to derefence a freed delegation stateid. Leading to the followint use-after-free KASAN warning: kernel: ================================================================== kernel: BUG: KASAN: slab-use-after-free in nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: Read of size 8 at addr ffff0000e73cd0c8 by task nfsd/6205 kernel: kernel: CPU: 2 UID: 0 PID: 6205 Comm: nfsd Kdump: loaded Not tainted 6.11.0-rc7+ #9 kernel: Hardware name: Apple Inc. Apple Virtualization Generic Platform, BIOS 2069.0.0.0.0 08/03/2024 kernel: Call trace: kernel: dump_backtrace+0x98/0x120 kernel: show_stack+0x1c/0x30 kernel: dump_stack_lvl+0x80/0xe8 kernel: print_address_description.constprop.0+0x84/0x390 kernel: print_report+0xa4/0x268 kernel: kasan_report+0xb4/0xf8 kernel: __asan_report_load8_noabort+0x1c/0x28 kernel: nfsd_breaker_owns_lease+0x140/0x160 [nfsd] kernel: nfsd_file_do_acquire+0xb3c/0x11d0 [nfsd] kernel: nfsd_file_acquire_opened+0x84/0x110 [nfsd] kernel: nfs4_get_vfs_file+0x634/0x958 [nfsd] kernel: nfsd4_process_open2+0xa40/0x1a40 [nfsd] kernel: nfsd4_open+0xa08/0xe80 [nfsd] kernel: nfsd4_proc_compound+0xb8c/0x2130 [nfsd] kernel: nfsd_dispatch+0x22c/0x718 [nfsd] kernel: svc_process_common+0x8e8/0x1960 [sunrpc] kernel: svc_process+0x3d4/0x7e0 [sunrpc] kernel: svc_handle_xprt+0x828/0xe10 [sunrpc] kernel: svc_recv+0x2cc/0x6a8 [sunrpc] kernel: nfsd+0x270/0x400 [nfsd] kernel: kthread+0x288/0x310 kernel: ret_from_fork+0x10/0x20 This patch proposes a fixed that's based on adding 2 new additional stid's sc_status values that help coordinate between the laundromat and other operations (nfsd4_free_stateid() and nfsd4_delegreturn()). First to make sure, that once the stid is marked revoked, it is not removed by the nfsd4_free_stateid(), the laundromat take a reference on the stateid. Then, coordinating whether the stid has been put on the cl_revoked list or we are processing FREE_STATEID and need to make sure to remove it from the list, each check that state and act accordingly. If laundromat has added to the cl_revoke list before the arrival of FREE_STATEID, then nfsd4_free_stateid() knows to remove it from the list. If nfsd4_free_stateid() finds that operations arrived before laundromat has placed it on cl_revoke list, it marks the state freed and then laundromat will no longer add it to the list. Also, for nfsd4_delegreturn() when looking for the specified stid, we need to access stid that are marked removed or freeable, it means the laundromat has started processing it but hasn't finished and this delegreturn needs to return nfserr_deleg_revoked and not nfserr_bad_stateid. The latter will not trigger a FREE_STATEID and the lack of it will leave this stid on the cl_revoked list indefinitely. Fixes: 2d4a532d385f ("nfsd: ensure that clp->cl_revoked list is protected by clp->cl_lock") CC: stable@vger.kernel.org Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-11Merge tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client fixes from Anna Schumaker: "Localio Bugfixes: - remove duplicated include in localio.c - fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put() - fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT - fix nfsd_file tracepoints to handle NULL rqstp pointers Other Bugfixes: - fix program selection loop in svc_process_common - fix integer overflow in decode_rc_list() - prevent NULL-pointer dereference in nfs42_complete_copies() - fix CB_RECALL performance issues when using a large number of delegations" * tag 'nfs-for-6.12-2' of git://git.linux-nfs.org/projects/anna/linux-nfs: NFS: remove revoked delegation from server's delegation list nfsd/localio: fix nfsd_file tracepoints to handle NULL rqstp nfs_common: fix Kconfig for NFS_COMMON_LOCALIO_SUPPORT nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put() NFSv4: Prevent NULL-pointer dereference in nfs42_complete_copies() SUNRPC: Fix integer overflow in decode_rc_list() sunrpc: fix prog selection loop in svc_process_common nfs: Remove duplicated include in localio.c
2024-10-10Merge tag 'nfsd-6.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fixes from Chuck Lever: - Fix NFSD bring-up / shutdown - Fix a UAF when releasing a stateid * tag 'nfsd-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: nfsd: fix possible badness in FREE_STATEID nfsd: nfsd_destroy_serv() must call svc_destroy() even if nfsd_startup_net() failed NFSD: Mark filecache "down" if init fails
2024-10-05nfsd: fix possible badness in FREE_STATEIDOlga Kornievskaia
When multiple FREE_STATEIDs are sent for the same delegation stateid, it can lead to a possible either use-after-free or counter refcount underflow errors. In nfsd4_free_stateid() under the client lock we find a delegation stateid, however the code drops the lock before calling nfs4_put_stid(), that allows another FREE_STATE to find the stateid again. The first one will proceed to then free the stateid which leads to either use-after-free or decrementing already zeroed counter. Fixes: 3f29cc82a84c ("nfsd: split sc_status out of sc_type") Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Reviewed-by: Benjamin Coddington <bcodding@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-10-04nfsd/localio: fix nfsd_file tracepoints to handle NULL rqstpMike Snitzer
Otherwise nfsd_file_acquire, nfsd_file_insert_err, and nfsd_file_cons_err will hit a NULL pointer when they are enabled and LOCALIO used. Example trace output (note xid is 0x0 and LOCALIO flag set): nfsd_file_acquire: xid=0x0 inode=0000000069a1b2e7 may_flags=WRITE|LOCALIO ref=1 nf_flags=HASHED|GC nf_may=WRITE nf_file=0000000070123234 status=0 Fixes: c63f0e48febf ("nfsd: add nfsd_file_acquire_local()") Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-10-03nfs_common: fix race in NFS calls to nfsd_file_put_local() and nfsd_serv_put()Mike Snitzer
Add nfs_to_nfsd_file_put_local() interface to fix race with nfsd module unload. Similarly, use RCU around nfs_open_local_fh()'s error path call to nfs_to->nfsd_serv_put(). Holding RCU ensures that NFS will safely _call and return_ from its nfs_to calls into the NFSD functions nfsd_file_put_local() and nfsd_serv_put(). Otherwise, if RCU isn't used then there is a narrow window when NFS's reference for the nfsd_file and nfsd_serv are dropped and the NFSD module could be unloaded, which could result in a crash from the return instruction for either nfs_to->nfsd_file_put_local() or nfs_to->nfsd_serv_put(). Reported-by: NeilBrown <neilb@suse.de> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-10-02inotify: Fix possible deadlock in fsnotify_destroy_markLizhi Xu
[Syzbot reported] WARNING: possible circular locking dependency detected 6.11.0-rc4-syzkaller-00019-gb311c1b497e5 #0 Not tainted ------------------------------------------------------ kswapd0/78 is trying to acquire lock: ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline] ffff88801b8d8930 (&group->mark_mutex){+.+.}-{3:3}, at: fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578 but task is already holding lock: ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:6841 [inline] ffffffff8ea2fd60 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0xbb4/0x35a0 mm/vmscan.c:7223 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: ... kmem_cache_alloc_noprof+0x3d/0x2a0 mm/slub.c:4044 inotify_new_watch fs/notify/inotify/inotify_user.c:599 [inline] inotify_update_watch fs/notify/inotify/inotify_user.c:647 [inline] __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:786 [inline] __se_sys_inotify_add_watch+0x72e/0x1070 fs/notify/inotify/inotify_user.c:729 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&group->mark_mutex){+.+.}-{3:3}: ... __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 fsnotify_group_lock include/linux/fsnotify_backend.h:270 [inline] fsnotify_destroy_mark+0x38/0x3c0 fs/notify/mark.c:578 fsnotify_destroy_marks+0x14a/0x660 fs/notify/mark.c:934 fsnotify_inoderemove include/linux/fsnotify.h:264 [inline] dentry_unlink_inode+0x2e0/0x430 fs/dcache.c:403 __dentry_kill+0x20d/0x630 fs/dcache.c:610 shrink_kill+0xa9/0x2c0 fs/dcache.c:1055 shrink_dentry_list+0x2c0/0x5b0 fs/dcache.c:1082 prune_dcache_sb+0x10f/0x180 fs/dcache.c:1163 super_cache_scan+0x34f/0x4b0 fs/super.c:221 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4815 shrink_many mm/vmscan.c:4876 [inline] lru_gen_shrink_node mm/vmscan.c:4954 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5934 kswapd_shrink_node mm/vmscan.c:6762 [inline] balance_pgdat mm/vmscan.c:6954 [inline] kswapd+0x1bcd/0x35a0 mm/vmscan.c:7223 [Analysis] The problem is that inotify_new_watch() is using GFP_KERNEL to allocate new watches under group->mark_mutex, however if dentry reclaim races with unlinking of an inode, it can end up dropping the last dentry reference for an unlinked inode resulting in removal of fsnotify mark from reclaim context which wants to acquire group->mark_mutex as well. This scenario shows that all notification groups are in principle prone to this kind of a deadlock (previously, we considered only fanotify and dnotify to be problematic for other reasons) so make sure all allocations under group->mark_mutex happen with GFP_NOFS. Reported-and-tested-by: syzbot+c679f13773f295d2da53@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c679f13773f295d2da53 Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20240927143642.2369508-1-lizhi.xu@windriver.com
2024-10-02Merge patch series "Fixup NLM and kNFSD file lock callbacks"Christian Brauner
Benjamin Coddington <bcodding@redhat.com> says: Last year both GFS2 and OCFS2 had some work done to make their locking more robust when exported over NFS. Unfortunately, part of that work caused both NLM (for NFS v3 exports) and kNFSD (for NFSv4.1+ exports) to no longer send lock notifications to clients. This in itself is not a huge problem because most NFS clients will still poll the server in order to acquire a conflicted lock, but now that I've noticed it I can't help but try to fix it because there are big advantages for setups that might depend on timely lock notifications, and we've supported that as a feature for a long time. Its important for NLM and kNFSD that they do not block their kernel threads inside filesystem's file_lock implementations because that can produce deadlocks. We used to make sure of this by only trusting that posix_lock_file() can correctly handle blocking lock calls asynchronously, so the lock managers would only setup their file_lock requests for async callbacks if the filesystem did not define its own lock() file operation. However, when GFS2 and OCFS2 grew the capability to correctly handle blocking lock requests asynchronously, they started signalling this behavior with EXPORT_OP_ASYNC_LOCK, and the check for also trusting posix_lock_file() was inadvertently dropped, so now most filesystems no longer produce lock notifications when exported over NFS. I tried to fix this by simply including the old check for lock(), but the resulting include mess and layering violations was more than I could accept. There's a much cleaner way presented here using an fop_flag, which while potentially flag-greedy, greatly simplifies the problem and grooms the way for future uses by both filesystems and lock managers alike. * patches from https://lore.kernel.org/r/cover.1726083391.git.bcodding@redhat.com: exportfs: Remove EXPORT_OP_ASYNC_LOCK NLM/NFSD: Fix lock notifications for async-capable filesystems gfs2/ocfs2: set FOP_ASYNC_LOCK fs: Introduce FOP_ASYNC_LOCK NFS: trace: show TIMEDOUT instead of 0x6e nfsd: use system_unbound_wq for nfsd_file_gc_worker() nfsd: count nfsd_file allocations nfsd: fix refcount leak when file is unhashed after being found nfsd: remove unneeded EEXIST error check in nfsd_do_file_acquire nfsd: add list_head nf_gc to struct nfsd_file Link: https://lore.kernel.org/r/cover.1726083391.git.bcodding@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-01NLM/NFSD: Fix lock notifications for async-capable filesystemsBenjamin Coddington
Instead of checking just the exportfs flag, use the new locks_can_async_lock() helper which allows NLM and NFSD to once again support lock notifications for all filesystems which use posix_lock_file(). Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Link: https://lore.kernel.org/r/865c40da44af67939e8eb560d17a26c9c50f23e0.1726083391.git.bcodding@redhat.com Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-09-23nfsd: implement server support for NFS_LOCALIO_PROGRAMMike Snitzer
The LOCALIO auxiliary RPC protocol consists of a single "UUID_IS_LOCAL" RPC method that allows the Linux NFS client to verify the local Linux NFS server can see the nonce (single-use UUID) the client generated and made available in nfs_common. The server expects this protocol to use the same transport as NFS and NFSACL for its RPCs. This protocol isn't part of an IETF standard, nor does it need to be considering it is Linux-to-Linux auxiliary RPC protocol that amounts to an implementation detail. The UUID_IS_LOCAL method encodes the client generated uuid_t in terms of the fixed UUID_SIZE (16 bytes). The fixed size opaque encode and decode XDR methods are used instead of the less efficient variable sized methods. The RPC program number for the NFS_LOCALIO_PROGRAM is 400122 (as assigned by IANA, see https://www.iana.org/assignments/rpc-program-numbers/ ): Linux Kernel Organization 400122 nfslocalio Signed-off-by: Mike Snitzer <snitzer@kernel.org> [neilb: factored out and simplified single localio protocol] Co-developed-by: NeilBrown <neilb@suse.de> Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfsd: add LOCALIO supportWeston Andros Adamson
Add server support for bypassing NFS for localhost reads, writes, and commits. This is only useful when both the client and server are running on the same host. If nfsd_open_local_fh() fails then the NFS client will both retry and fallback to normal network-based read, write and commit operations if localio is no longer supported. Care is taken to ensure the same NFS security mechanisms are used (authentication, etc) regardless of whether localio or regular NFS access is used. The auth_domain established as part of the traditional NFS client access to the NFS server is also used for localio. Store auth_domain for localio in nfsd_uuid_t and transfer it to the client if it is local to the server. Relative to containers, localio gives the client access to the network namespace the server has. This is required to allow the client to access the server's per-namespace nfsd_net struct. This commit also introduces the use of NFSD's percpu_ref to interlock nfsd_destroy_serv and nfsd_open_local_fh, to ensure nn->nfsd_serv is not destroyed while in use by nfsd_open_local_fh and other LOCALIO client code. CONFIG_NFS_LOCALIO enables NFS server support for LOCALIO. Signed-off-by: Weston Andros Adamson <dros@primarydata.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Co-developed-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Co-developed-by: NeilBrown <neilb@suse.de> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfs_common: prepare for the NFS client to use nfsd_file for LOCALIOMike Snitzer
The next commit will introduce nfsd_open_local_fh() which returns an nfsd_file structure. This commit exposes LOCALIO's required NFSD symbols to the NFS client: - Make nfsd_open_local_fh() symbol and other required NFSD symbols available to NFS in a global 'nfs_to' nfsd_localio_operations struct (global access suggested by Trond, nfsd_localio_operations suggested by NeilBrown). The next commit will also introduce nfsd_localio_ops_init() that init_nfsd() will call to initialize 'nfs_to'. - Introduce nfsd_file_file() that provides access to nfsd_file's backing file. Keeps nfsd_file structure opaque to NFS client (as suggested by Jeff Layton). - Introduce nfsd_file_put_local() that will put the reference to the nfsd_file's associated nn->nfsd_serv and then put the reference to the nfsd_file (as suggested by NeilBrown). Suggested-by: Trond Myklebust <trond.myklebust@hammerspace.com> # nfs_to Suggested-by: NeilBrown <neilb@suse.de> # nfsd_localio_operations Suggested-by: Jeff Layton <jlayton@kernel.org> # nfsd_file_file Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23SUNRPC: replace program list with program arrayNeilBrown
A service created with svc_create_pooled() can be given a linked list of programs and all of these will be served. Using a linked list makes it cumbersome when there are several programs that can be optionally selected with CONFIG settings. After this patch is applied, API consumers must use only svc_create_pooled() when creating an RPC service that listens for more than one RPC program. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Acked-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
2024-09-23nfsd: add nfsd_serv_try_get and nfsd_serv_putMike Snitzer
Introduce nfsd_serv_try_get and nfsd_serv_put and update the nfsd code to prevent nfsd_destroy_serv from destroying nn->nfsd_serv until any caller of nfsd_serv_try_get releases their reference using nfsd_serv_put. A percpu_ref is used to implement the interlock between nfsd_destroy_serv and any caller of nfsd_serv_try_get. This interlock is needed to properly wait for the completion of client initiated localio calls to nfsd (that are _not_ in the context of nfsd). Signed-off-by: Mike Snitzer <snitzer@kernel.org> Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>