kernel/git/stable/linux.git/fs/nfs/flexfilelayout/flexfilelayoutdev.c, branch master

NFSv4/pnfs: key the data server cache on the NFS version

2026-08-20T22:18:20+00:00

nfs4_pnfs_ds_add() keys the per-net data server cache on the multipath address set alone, and struct nfs4_pnfs_ds records no version. That suffices for the files layout driver, which always connects with version 4, but flexfiles takes its version tuple from GETDEVICEINFO per device, and one address can legitimately serve both NFSv3 and NFSv4. Two deviceids on one address with different ds_versions[0].version therefore share a single nfs4_pnfs_ds, and whichever mirror connects first pins ds_clp to its own version. The other one is handed that client anyway, so it selects rpc_call_ops for a version the connection does not speak, and the mismatched sequence-slot handling dereferences NULL. Add the version to the cache key so the two cannot alias, giving each version its own nfs4_pnfs_ds and connection while both mirrors stay usable. Only the major version is compared, since that is what selects rpc_call_ops and rpc_ops; v4.0 and v4.1 keep sharing a client. The files layout driver passes the 4 it already hardcodes at connect time. Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Reported-by: Yuhao Jiang Assisted-by: Claude:claude-opus-5 Signed-off-by: Junrui Luo Signed-off-by: Trond Myklebust

NFSv4/flexfiles: support loosely coupled data servers

2026-08-17T16:02:08+00:00

A flexfiles storage device is tightly coupled to the MDS only when the decoded ds_versions[0].tightly_coupled flag is set (RFC 8435, sections 2.3 and 4.1). The client currently ignores that flag and treats every data server as tightly coupled, which breaks I/O to loosely coupled DSes. Two things force that assumption on an NFSv4.1+ DS: 1) nfs4_set_ds_client() always sets NFS_CS_PNFS on the new client, so EXCHANGE_ID is sent with EXCHGID4_FLAG_USE_PNFS_DS. 2) nfs4_init_ds_session() then calls is_ds_client() and returns -ENODEV if the reply does not carry EXCHGID4_FLAG_USE_PNFS_DS. A loosely coupled DS is just a normal NFS server and does not act in the pNFS DS role, so the client must not require it to advertise that role. Thread the ds_versions[0].tightly_coupled flag from the flexfiles driver down to the DS connect path. When it is false, skip both the NFS_CS_PNFS flag and the is_ds_client() check. The file layout driver always passes true because NFSv4.1 file layout data servers use the pNFS DS role. Signed-off-by: Jeuk Kim Signed-off-by: Trond Myklebust

pnfs/flexfiles: validate ds_versions_cnt is non-zero

2026-04-13T21:04:16+00:00

nfs4_ff_alloc_deviceid_node() reads version_count from XDR without checking it is non-zero. When a malicious NFS server sends a pNFS LAYOUTGET response with version_count=0, kcalloc(0, ...) returns ZERO_SIZE_PTR (0x10). The subsequent ds_versions[0] access in nfs4_ff_layout_ds_version() and other callers dereferences this invalid pointer, causing an out-of-bounds read. Add a check for version_count == 0 after parsing it from XDR, before the allocation. The OOB read was confirmed with KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] from accessing ZERO_SIZE_PTR. Fixes: d67ae825a59d ("pnfs/flexfiles: Add the FlexFile Layout Driver") Reported-by: Klaudia Kloc Reported-by: Dawid Moczadło Tested-by: Jenny Guanni Qu Signed-off-by: Jenny Guanni Qu Signed-off-by: Trond Myklebust

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

pnfs/flexfiles: Fix memory leak in nfs4_ff_alloc_deviceid_node()

2026-01-05T04:03:25+00:00

In nfs4_ff_alloc_deviceid_node(), if the allocation for ds_versions fails, the function jumps to the out_scratch label without freeing the already allocated dsaddrs list, leading to a memory leak. Fix this by jumping to the out_err_drain_dsaddrs label, which properly frees the dsaddrs list before cleaning up other resources. Fixes: d67ae825a59d6 ("pnfs/flexfiles: Add the FlexFile Layout Driver") Signed-off-by: Zilin Guan Signed-off-by: Trond Myklebust

NFSv4/flexfiles: Update low level helper functions to be DS stripe aware.

2025-09-26T19:35:02+00:00

Updates common helper functions to be dss_id aware. Most cases simply add a dss_id parameter. The has_available functions have been updated with a loop. Signed-off-by: Jonathan Curley Signed-off-by: Anna Schumaker

NFSv4/flexfiles: Add data structure support for striped layouts

2025-09-26T19:32:24+00:00

Adds a new struct nfs4_ff_layout_ds_stripe that represents a data server stripe within a layout. A new dynamically allocated array of this type has been added to nfs4_ff_layout_mirror and per stripe configuration information has been moved from the mirror type to the stripe based on the RFC. Signed-off-by: Jonathan Curley Signed-off-by: Anna Schumaker

NFS: Update the flexfilelayout driver to use xdr_set_scratch_folio()

2025-09-23T17:29:50+00:00

Signed-off-by: Anna Schumaker

pNFS/flexfiles: don't attempt pnfs on fatal DS errors

2025-07-22T12:10:17+00:00

When an applications get killed (SIGTERM/SIGINT) while pNFS client performs a connection to DS, client ends in an infinite loop of connect-disconnect. This source of the issue, it that flexfilelayoutdev#nfs4_ff_layout_prepare_ds gets an error on nfs4_pnfs_ds_connect with status ERESTARTSYS, which is set by rpc_signal_task, but the error is treated as transient, thus retried. The issue is reproducible with Ctrl+C the following script(there should be ~1000 files in a directory, client should must not have any connections to DSes): ``` echo 3 > /proc/sys/vm/drop_caches for i in * do head -1 $i done ``` The change aims to propagate the nfs4_ff_layout_prepare_ds error state to the caller that can decide whatever this is a retryable error or not. Signed-off-by: Tigran Mkrtchyan Link: https://lore.kernel.org/r/20250627071751.189663-1-tigran.mkrtchyan@desy.de Fixes: 260f32adb88d ("pNFS/flexfiles: Check the result of nfs4_pnfs_ds_connect") Signed-off-by: Trond Myklebust

NFS: always probe for LOCALIO support asynchronously

2025-05-28T21:17:13+00:00

It was reported that NFS client mounts of AWS Elastic File System (EFS) volumes is slow, this is because the AWS firewall disallows LOCALIO (because it doesn't consider the use of NFS_LOCALIO_PROGRAM valid), see: https://bugzilla.redhat.com/show_bug.cgi?id=2335129 Switch to performing the LOCALIO probe asynchronously to address the potential for the NFS LOCALIO protocol being disallowed and/or slowed by the remote server's response. While at it, fix nfs_local_probe_async() to always take/put a reference on the nfs_client that is using the LOCALIO protocol. Also, unexport the nfs_local_probe() symbol and make it private to fs/nfs/localio.c This change has the side-effect of initially issuing reads, writes and commits over the wire via SUNRPC until the LOCALIO probe completes. Suggested-by: Jeff Layton # to always probe async Fixes: 76d4cb6345da ("nfs: probe for LOCALIO when v4 client reconnects to server") Cc: stable@vger.kernel.org # 6.14+ Signed-off-by: Mike Snitzer Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker