kernel/linux.git/net/sunrpc, branch master

Merge tag 'nfs-for-7.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2026-04-24T21:20:03+00:00

Pull NFS client updates from Trond Myklebust: "Bugfixes: - Fix handling of ENOSPC so that if we have to resend writes, they are written synchronously - SUNRPC RDMA transport fixes from Chuck - Several fixes for delegated timestamps in NFSv4.2 - Failure to obtain a directory delegation should not cause stat() to fail with NFSv4 - Rename was failing to update timestamps when a directory delegation is held on NFSv4 - Ensure we check rsize/wsize after crossing a NFSv4 filesystem boundary - NFSv4/pnfs: - If the server is down, retry the layout returns on reboot - Fallback to MDS could result in a short write being incorrectly logged Cleanups: - Use memcpy_and_pad in decode_fh" * tag 'nfs-for-7.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (21 commits) NFS: Fix RCU dereference of cl_xprt in nfs_compare_super_address NFS: remove redundant __private attribute from nfs_page_class NFSv4.2: fix CLONE/COPY attrs in presence of delegated attributes NFS: fix writeback in presence of errors nfs: use memcpy_and_pad in decode_fh NFSv4.1: Apply session size limits on clone path NFSv4: retry GETATTR if GET_DIR_DELEGATION failed NFS: fix RENAME attr in presence of directory delegations pnfs/flexfiles: validate ds_versions_cnt is non-zero NFS/blocklayout: print each device used for SCSI layouts xprtrdma: Post receive buffers after RPC completion xprtrdma: Scale receive batch size with credit window xprtrdma: Replace rpcrdma_mr_seg with xdr_buf cursor xprtrdma: Decouple frwr_wp_create from frwr_map xprtrdma: Close lost-wakeup race in xprt_rdma_alloc_slot xprtrdma: Avoid 250 ms delay on backlog wakeup xprtrdma: Close sendctx get/put race that can block a transport nfs: update inode ctime after removexattr operation nfs: fix utimensat() for atime with delegated timestamps NFS: improve "Server wrote zero bytes" error ...

Merge tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

2026-04-20T17:44:02+00:00

Pull nfsd updates from Chuck Lever: - filehandle signing to defend against filehandle-guessing attacks (Benjamin Coddington) The server now appends a SipHash-2-4 MAC to each filehandle when the new "sign_fh" export option is enabled. NFSD then verifies filehandles received from clients against the expected MAC; mismatches return NFS error STALE - convert the entire NLMv4 server-side XDR layer from hand-written C to xdrgen-generated code, spanning roughly thirty patches (Chuck Lever) XDR functions are generally boilerplate code and are easy to get wrong. The goals of this conversion are improved memory safety, lower maintenance burden, and groundwork for eventual Rust code generation for these functions. - improve pNFS block/SCSI layout robustness with two related changes (Dai Ngo) SCSI persistent reservation fencing is now tracked per client and per device via an xarray, to avoid both redundant preempt operations on devices already fenced and a potential NFSD deadlock when all nfsd threads are waiting for a layout return. - scalability and infrastructure improvements Sincere thanks to all contributors, reviewers, testers, and bug reporters who participated in the v7.1 NFSD development cycle. * tag 'nfsd-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (83 commits) NFSD: Docs: clean up pnfs server timeout docs nfsd: fix comment typo in nfsxdr nfsd: fix comment typo in nfs3xdr NFSD: convert callback RPC program to per-net namespace NFSD: use per-operation statidx for callback procedures svcrdma: Use contiguous pages for RDMA Read sink buffers SUNRPC: Add svc_rqst_page_release() helper SUNRPC: xdr.h: fix all kernel-doc warnings svcrdma: Factor out WR chain linking into helper svcrdma: Add Write chunk WRs to the RPC's Send WR chain svcrdma: Clean up use of rdma->sc_pd->device svcrdma: Clean up use of rdma->sc_pd->device in Receive paths svcrdma: Add fair queuing for Send Queue access SUNRPC: Optimize rq_respages allocation in svc_alloc_arg SUNRPC: Track consumed rq_pages entries svcrdma: preserve rq_next_page in svc_rdma_save_io_pages SUNRPC: Handle NULL entries in svc_rqst_release_pages SUNRPC: Allocate a separate Reply page array SUNRPC: Tighten bounds checking in svc_rqst_replace_page NFSD: Sign filehandles ...

xprtrdma: Post receive buffers after RPC completion

2026-04-13T19:05:01+00:00

rpcrdma_post_recvs() runs in CQ poll context and its cost falls on the latency-critical path between polling a Receive completion and waking the RPC consumer. Every cycle spent refilling the Receive Queue delays delivery of the reply to the NFS layer. Move the rpcrdma_post_recvs() call in rpcrdma_reply_handler() to after the RPC has been decoded and completed. The larger batch size from the preceding patch provides sufficient Receive Queue headroom to absorb the brief delay before buffers are replenished. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Scale receive batch size with credit window

2026-04-13T19:05:00+00:00

The fixed RPCRDMA_MAX_RECV_BATCH of 7 results in frequent small ib_post_recv batches during high-rate workloads. With a 128-slot credit window, receives are reposted every 7th completion, each batch incurring atomic serialization and a doorbell write. Replace the fixed batch constant with a per-endpoint value scaled to 25% of the negotiated credit window. For a typical 128-credit connection this raises the batch from 7 to 32, reducing doorbell frequency by roughly 4x and amortizing the per-batch atomic and MMIO costs over a larger group of receive WRs. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Replace rpcrdma_mr_seg with xdr_buf cursor

2026-04-13T19:04:58+00:00

The FRWR registration path converts data through three representations: xdr_buf -> rpcrdma_mr_seg[] -> scatterlist[] -> ib_map_mr_sg(). The rpcrdma_mr_seg intermediate is a relic of when multiple registration strategies existed (FMR, physical, FRWR). Only FRWR remains, so this indirection and the 6240-byte rl_segments[260] array embedded in each rpcrdma_req serve no purpose. Introduce struct rpcrdma_xdr_cursor to track position within an xdr_buf during iterative MR registration. Rewrite frwr_map to populate scatterlist entries directly from the xdr_buf regions (head kvec, page list, tail kvec). The boundary logic for non-SG_GAPS devices is simpler because the xdr_buf structure guarantees that page-region entries after the first start at offset 0, and that head/tail kvecs are separate regions that naturally break at MR boundaries. Fix a pre-existing bug in rpcrdma_encode_write_list where the write-pad statistics accumulator added mr->mr_length from the last data MR rather than the write-pad MR. The refactored code uses ep->re_write_pad_mr->mr_length. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Decouple frwr_wp_create from frwr_map

2026-04-13T18:56:27+00:00

frwr_wp_create is the only caller of frwr_map outside the encode path. It registers a single 4-byte write-pad region from a stack- local rpcrdma_mr_seg. Inlining the registration logic directly (sg_init_table + sg_set_page + ib_dma_map_sg + ib_map_mr_sg + IOVA mangle + reg_wr setup) eliminates the coupling that would otherwise complicate the removal of rpcrdma_mr_seg from frwr_map's interface. The inlined version adds a proper error-unwind ladder: on failure, the DMA mapping (if established) is released, ep->re_write_pad_mr is cleared, and the MR is returned to the transport free list. The old frwr_map-based code relied on rpcrdma_mrs_destroy at teardown to reclaim partially-initialized MRs. This is a one-time setup path; duplicating ~20 lines is a reasonable tradeoff for decoupling the write-pad registration from the data- path MR registration. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Close lost-wakeup race in xprt_rdma_alloc_slot

2026-04-13T18:56:20+00:00

xprt_rdma_alloc_slot() and xprt_rdma_free_slot() lack serialization between the buffer pool and the backlog queue. A buffer freed after rpcrdma_buffer_get() finds the pool empty but before rpc_sleep_on() places the task on the backlog is returned to the pool with no waiter to wake, leaving the task stuck on the backlog indefinitely. After joining the backlog, re-check the pool and route any recovered buffer through xprt_wake_up_backlog(), whose queue lock serializes with concurrent wakeups and avoids double-assignment of slots. Because xprt_rdma_free_slot() does not hold reserve_lock, the XPRT_CONGESTED double-check in xprt_throttle_congested() is ineffective: a task can join the backlog through that path after free_slot has already found it empty and cleared the bit. Avoid this by using xprt_add_backlog_noncongested(), which queues the task without setting XPRT_CONGESTED, so every allocation reaches xprt_rdma_alloc_slot() and its post-sleep re-check. Fixes: edb41e61a54e ("xprtrdma: Make rpc_rqst part of rpcrdma_req") Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Avoid 250 ms delay on backlog wakeup

2026-04-13T18:52:54+00:00

Commit a721035477fb ("SUNRPC/xprt: async tasks mustn't block waiting for memory") changed xprt_rdma_alloc_slot() to set tk_status to -ENOMEM so that call_reserveresult() would sleep HZ/4 before retrying. That rationale applies to xprt_dynamic_alloc_slot(), where an immediate retry under memory pressure wastes CPU, but not to the RDMA backlog path: a task woken from the backlog has a slot waiting for it, so the 250 ms rpc_delay adds latency without benefit. This also aligns the code with the existing kernel-doc for xprt_rdma_alloc_slot(), which already documented %-EAGAIN. Fixes: a721035477fb ("SUNRPC/xprt: async tasks mustn't block waiting for memory") Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

xprtrdma: Close sendctx get/put race that can block a transport

2026-04-13T18:52:49+00:00

rpcrdma_sendctx_get_locked() and rpcrdma_sendctx_put_locked() can race in a way that leaves XPRT_WRITE_SPACE set permanently, blocking all further sends on the transport: get_locked put_locked (Send completion) ---------- -------------------------- read rb_sc_tail -> ring full advance rb_sc_tail xprt_write_space(): test_bit(WRITE_SPACE) -> not set, return set_bit(WRITE_SPACE) return NULL (-EAGAIN) After the sender releases XPRT_LOCKED, the release path refuses to wake the next task because XPRT_WRITE_SPACE is set. The sender retries, finds XPRT_WRITE_SPACE still set, and sleeps on xprt_sending. No further Send completions arrive to clear the flag because no new Sends can be posted. With nconnect, the stalled transport's share of congestion credits are never returned, starving the remaining transports as well. Fixes: 05eb06d86685 ("xprtrdma: Fix occasional transport deadlock") Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

kernfs: pass struct ns_common instead of const void * for namespace tags

2026-04-09T12:36:52+00:00

kernfs has historically used const void * to pass around namespace tags used for directory-level namespace filtering. The only current user of this is sysfs network namespace tagging where struct net pointers are cast to void *. Replace all const void * namespace parameters with const struct ns_common * throughout the kernfs, sysfs, and kobject namespace layers. This includes the kobj_ns_type_operations callbacks, kobject_namespace(), and all sysfs/kernfs APIs that accept or return namespace tags. Passing struct ns_common is needed because various codepaths require access to the underlying namespace. A struct ns_common can always be converted back to the concrete namespace type (e.g., struct net) via container_of() or to_ns_common() in the reverse direction. This is a preparatory change for switching to ns_id-based directory iteration to prevent a KASLR pointer leak through the current use of raw namespace pointers as hash seeds and comparison keys. Signed-off-by: Christian Brauner