kernel/linux.git/fs/nfsd/filecache.c, branch v6.18.22

Merge tag 'nfsd-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2025-10-06T20:22:21+00:00

Pull nfsd updates from Chuck Lever: "Mike Snitzer has prototyped a mechanism for disabling I/O caching in NFSD. This is introduced in v6.18 as an experimental feature. This enables scaling NFSD in /both/ directions: - NFS service can be supported on systems with small memory footprints, such as low-cost cloud instances - Large NFS workloads will be less likely to force the eviction of server-local activity, helping it avoid thrashing Jeff Layton contributed a number of fixes to the new attribute delegation implementation (based on a pending Internet RFC) that we hope will make attribute delegation reliable enough to enable by default, as it is on the Linux NFS client. The remaining patches in this pull request are clean-ups and minor optimizations. Many thanks to the contributors, reviewers, testers, and bug reporters who participated during the v6.18 NFSD development cycle" * tag 'nfsd-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (42 commits) nfsd: discard nfserr_dropit SUNRPC: Make RPCSEC_GSS_KRB5 select CRYPTO instead of depending on it NFSD: Add io_cache_{read,write} controls to debugfs NFSD: Do the grace period check in ->proc_layoutget nfsd: delete unnecessary NULL check in __fh_verify() NFSD: Allow layoutcommit during grace period NFSD: Disallow layoutget during grace period sunrpc: fix "occurence"->"occurrence" nfsd: Don't force CRYPTO_LIB_SHA256 to be built-in nfsd: nfserr_jukebox in nlm_fopen should lead to a retry NFSD: Reduce DRC bucket size NFSD: Delay adding new entries to LRU SUNRPC: Move the svc_rpcb_cleanup() call sites NFS: Remove rpcbind cleanup for NFSv4.0 callback nfsd: unregister with rpcbind when deleting a transport NFSD: Drop redundant conversion to bool sunrpc: eliminate return pointer in svc_tcp_sendmsg() sunrpc: fix pr_notice in svc_tcp_sendto() to show correct length nfsd: decouple the xprtsec policy check from check_nfsd_access() NFSD: Fix destination buffer size in nfsd4_ssc_setup_dul() ...

Merge tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2025-10-03T21:20:40+00:00

Pull NFS client updates from Anna Schumaker: "New Features: - Add a Kconfig option to redirect dfprintk() to the trace buffer - Enable use of the RWF_DONTCACHE flag on the NFS client - Add striped layout handling to pNFS flexfiles - Add proper localio handling for READ and WRITE O_DIRECT Bugfixes: - Handle NFS4ERR_GRACE errors during delegation recall - Fix NFSv4.1 backchannel max_resp_sz verification check - Fix mount hang after CREATE_SESSION failure - Fix d_parent->d_inode locking in nfs4_setup_readdir() Other Cleanups and Improvements: - Improvements to write handling tracepoints - Fix a few trivial spelling mistakes - Cleanups to the rpcbind cleanup call sites - Convert the SUNRPC xdr_buf to use a scratch folio instead of scratch page - Remove unused NFS_WBACK_BUSY() macro - Remove __GFP_NOWARN flags - Unexport rpc_malloc() and rpc_free()" * tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (46 commits) NFS: add basic STATX_DIOALIGN and STATX_DIO_READ_ALIGN support nfs/localio: add tracepoints for misaligned DIO READ and WRITE support nfs/localio: add proper O_DIRECT support for READ and WRITE nfs/localio: refactor iocb initialization nfs/localio: refactor iocb and iov_iter_bvec initialization nfs/localio: avoid issuing misaligned IO using O_DIRECT nfs/localio: make trace_nfs_local_open_fh more useful NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support sunrpc: unexport rpc_malloc() and rpc_free() NFSv4/flexfiles: Add support for striped layouts NFSv4/flexfiles: Update layout stats & error paths for striped layouts NFSv4/flexfiles: Write path updates for striped layouts NFSv4/flexfiles: Commit path updates for striped layouts NFSv4/flexfiles: Read path updates for striped layouts NFSv4/flexfiles: Update low level helper functions to be DS stripe aware. NFSv4/flexfiles: Add data structure support for striped layouts NFSv4/flexfiles: Use ds_commit_idx when marking a write commit NFSv4/flexfiles: Remove cred local variable dependency nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing NFS: Enable use of the RWF_DONTCACHE flag on the NFS client ...

NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support

2025-09-30T20:10:05+00:00

Use STATX_DIOALIGN and STATX_DIO_READ_ALIGN to get DIO alignment attributes from the underlying filesystem and store them in the associated nfsd_file. This is done when the nfsd_file is first opened for each regular file. Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Reviewed-by: NeilBrown Signed-off-by: Chuck Lever Acked-by: Chuck Lever Signed-off-by: Anna Schumaker

nfsd: discard nfsd_file_get_local()

2025-09-21T23:24:50+00:00

This interface was deprecated by commit e6f7e1487ab5 ("nfs_localio: simplify interface to nfsd for getting nfsd_file") and is now unused. So let's remove it. Signed-off-by: NeilBrown Reviewed-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

fs: replace use of system_unbound_wq with system_dfl_wq

2025-09-19T14:15:07+00:00

Currently if a user enqueue a work item using schedule_delayed_work() the used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to schedule_work() that is using system_wq and queue_work(), that makes use again of WORK_CPU_UNBOUND. This lack of consistentcy cannot be addressed without refactoring the API. system_unbound_wq should be the default workqueue so as not to enforce locality constraints for random work whenever it's not required. Adding system_dfl_wq to encourage its use when unbound work should be used. The old system_unbound_wq will be kept for a few release cycles. Suggested-by: Tejun Heo Signed-off-by: Marco Crivellari Link: https://lore.kernel.org/20250916082906.77439-2-marco.crivellari@suse.com Signed-off-by: Christian Brauner

NFSD: Clean up kdoc for nfsd_file_put_local()

2025-07-14T16:46:44+00:00

Sparse reports that the synopsis of nfsd_file_put_local() does not match its kdoc comment. Introduced by commit c25a89770d1f ("nfs_localio: change nfsd_file_put_local() to take a pointer to __rcu pointer") . Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

nfs_localio: change nfsd_file_put_local() to take a pointer to __rcu pointer

2025-05-28T21:17:14+00:00

Instead of calling xchg() and unrcu_pointer() before nfsd_file_put_local(), we now pass pointer to the __rcu pointer and call xchg() and unrcu_pointer() inside that function. Where unrcu_pointer() is currently called the internals of "struct nfsd_file" are not known and that causes older compilers such as gcc-8 to complain. In some cases we have a __kernel (aka normal) pointer not an __rcu pointer so we need to cast it to __rcu first. This is strictly a weakening so no information is lost. Somewhat surprisingly, this cast is accepted by gcc-8. This has the pleasing result that the cmpxchg() which sets ro_file and rw_file, and also the xchg() which clears them, are both now in the nfsd code. Reported-by: Pali Rohár Reported-by: Vincent Mailhol Fixes: 86e00412254a ("nfs: cache all open LOCALIO nfsd_file(s) in client") Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker

nfs_localio: always hold nfsd net ref with nfsd_file ref

2025-05-28T21:17:14+00:00

Having separate nfsd_file_put and nfsd_file_put_local in struct nfsd_localio_operations doesn't make much sense. The difference is that nfsd_file_put doesn't drop a reference to the nfs_net which is what keeps nfsd from shutting down. Currently, if nfsd tries to shutdown it will invalidate the files stored in the list from the nfs_uuid and this will drop all references to the nfsd net that the client holds. But the client could still hold some references to nfsd_files for active IO. So nfsd might think is has completely shut down local IO, but hasn't and has no way to wait for those active IO requests to complete. So this patch changes nfsd_file_get to nfsd_file_get_local and has it increase the ref count on the nfsd net and it replaces all calls to ->nfsd_put_file to ->nfsd_put_file_local. It also changes ->nfsd_open_local_fh to return with the refcount on the net elevated precisely when a valid nfsd_file is returned. This means that whenever the client holds a valid nfsd_file, there will be an associated count on the nfsd net, and so the count can only reach zero when all nfsd_files have been returned. nfs_local_file_put() is changed to call nfs_to_nfsd_file_put_local() instead of replacing calls to one with calls to the other because this will help a later patch which changes nfs_to_nfsd_file_put_local() to take an __rcu pointer while nfs_local_file_put() doesn't. Fixes: 86e00412254a ("nfs: cache all open LOCALIO nfsd_file(s) in client") Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker

nfsd: filecache: drop the list_lru lock during lock gc scans

2025-03-10T13:11:08+00:00

Under a high NFSv3 load with lots of different files being accessed, the LRU list of garbage-collectable files can become quite long. Asking list_lru_scan_node() to scan the whole list can result in a long period during which a spinlock is held, blocking the addition of new LRU items. So ask list_lru_scan_node() to scan only a few entries at a time, and repeat until the scan is complete. If the shrinker runs between two consecutive calls of list_lru_scan_node() it could invalidate the "remaining" counter which could lead to premature freeing. So add a spinlock to avoid that. Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: filecache: don't repeatedly add/remove files on the lru list

2025-03-10T13:11:07+00:00

There is no need to remove a file from the lru every time we access it, and then add it back. It is sufficient to set the REFERENCED flag every time we put the file. The order in the lru of REFERENCED files is largely irrelevant as they will all be moved to the end. With this patch, files are added only when they are allocated (if want_gc) and they are removed only by the list_lru_(shrink_)walk callback or when forcibly removing a file. This should reduce contention on the list_lru spinlock(s) and reduce memory traffic a little. Signed-off-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever