Commit Graph

1398296 Commits

Author SHA1 Message Date
Chuck Lever
ad3cbbb0c1 NFSD: Clear TIME_DELEG in the suppattr_exclcreat bitmap
>From RFC 8881:

5.8.1.14. Attribute 75: suppattr_exclcreat

> The bit vector that would set all REQUIRED and RECOMMENDED
> attributes that are supported by the EXCLUSIVE4_1 method of file
> creation via the OPEN operation. The scope of this attribute
> applies to all objects with a matching fsid.

There's nothing in RFC 8881 that states that suppattr_exclcreat is
or is not allowed to contain bits for attributes that are clear in
the reported supported_attrs bitmask. But it doesn't make sense for
an NFS server to indicate that it /doesn't/ implement an attribute,
but then also indicate that clients /are/ allowed to set that
attribute using OPEN(create) with EXCLUSIVE4_1.

The FATTR4_WORD2_TIME_DELEG attributes are also not to be allowed
for OPEN(create) with EXCLUSIVE4_1. It doesn't make sense to set
a delegated timestamp on a new file.

Fixes: 7e13f4f8d2 ("nfsd: handle delegated timestamps in SETATTR")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-18 11:18:39 -05:00
Chuck Lever
27d17641ca NFSD: Clear SECLABEL in the suppattr_exclcreat bitmap
>From RFC 8881:

5.8.1.14. Attribute 75: suppattr_exclcreat

> The bit vector that would set all REQUIRED and RECOMMENDED
> attributes that are supported by the EXCLUSIVE4_1 method of file
> creation via the OPEN operation. The scope of this attribute
> applies to all objects with a matching fsid.

There's nothing in RFC 8881 that states that suppattr_exclcreat is
or is not allowed to contain bits for attributes that are clear in
the reported supported_attrs bitmask. But it doesn't make sense for
an NFS server to indicate that it /doesn't/ implement an attribute,
but then also indicate that clients /are/ allowed to set that
attribute using OPEN(create) with EXCLUSIVE4_1.

Ensure that the SECURITY_LABEL and ACL bits are not set in the
suppattr_exclcreat bitmask when they are also not set in the
supported_attrs bitmask.

Fixes: 8c18f2052e ("nfsd41: SUPPATTR_EXCLCREAT attribute")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-18 11:18:39 -05:00
Shardul Bankar
df8d829bba nfsd: fix memory leak in nfsd_create_serv error paths
When nfsd_create_serv() calls percpu_ref_init() to initialize
nn->nfsd_net_ref, it allocates both a percpu reference counter
and a percpu_ref_data structure (64 bytes). However, if the
function fails later due to svc_create_pooled() returning NULL
or svc_bind() returning an error, these allocations are not
cleaned up, resulting in a memory leak.

The leak manifests as:
- Unreferenced percpu allocation (8 bytes per CPU)
- Unreferenced percpu_ref_data structure (64 bytes)

Fix this by adding percpu_ref_exit() calls in both error paths
to properly clean up the percpu_ref_init() allocations.

This patch fixes the percpu_ref leak in nfsd_create_serv() seen
as an auxiliary leak in syzbot report 099461f8558eb0a1f4f3; the
prepare_creds() and vsock-related leaks in the same report
remain to be addressed separately.

Reported-by: syzbot+099461f8558eb0a1f4f3@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=099461f8558eb0a1f4f3
Fixes: 47e988147f ("nfsd: add nfsd_serv_try_get and nfsd_serv_put")
Signed-off-by: Shardul Bankar <shardul.b@mpiricsoftware.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-18 11:18:39 -05:00
Andy Shevchenko
ebae102897 nfsd: Mark variable __maybe_unused to avoid W=1 build break
Clang is not happy about set but (in some cases) unused variable:

fs/nfsd/export.c:1027:17: error: variable 'inode' set but not used [-Werror,-Wunused-but-set-variable]

since it's used as a parameter to dprintk() which might be configured
a no-op. To avoid uglifying code with the specific ifdeffery just mark
the variable __maybe_unused.

The commit [1], which introduced this behaviour, is quite old and hence
the Fixes tag points to the first of the Git era.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=0431923fb7a1 [1]
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-08 10:56:34 -05:00
Joshua Rogers
d1bea0ce35 svcrdma: bound check rq_pages index in inline path
svc_rdma_copy_inline_range indexed rqstp->rq_pages[rc_curpage] without
verifying rc_curpage stays within the allocated page array. Add guards
before the first use and after advancing to a new page.

Fixes: d7cc739726 ("svcrdma: support multiple Read chunks per RPC")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-08 10:51:26 -05:00
Joshua Rogers
94972027ab svcrdma: return 0 on success from svc_rdma_copy_inline_range
The function comment specifies 0 on success and -EINVAL on invalid
parameters. Make the tail return 0 after a successful copy loop.

Fixes: d7cc739726 ("svcrdma: support multiple Read chunks per RPC")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-08 10:51:26 -05:00
Joshua Rogers
a8ee9099f3 svcrdma: use rc_pageoff for memcpy byte offset
svc_rdma_copy_inline_range added rc_curpage (page index) to the page
base instead of the byte offset rc_pageoff. Use rc_pageoff so copies
land within the current page.

Found by ZeroPath (https://zeropath.com)

Fixes: 8e12258268 ("svcrdma: Move svc_rdma_read_info::ri_pageno to struct svc_rdma_recv_ctxt")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-08 10:51:26 -05:00
Joshua Rogers
d4b69a6186 SUNRPC: svcauth_gss: avoid NULL deref on zero length gss_token in gss_read_proxy_verf
A zero length gss_token results in pages == 0 and in_token->pages[0]
is NULL. The code unconditionally evaluates
page_address(in_token->pages[0]) for the initial memcpy, which can
dereference NULL even when the copy length is 0. Guard the first
memcpy so it only runs when length > 0.

Fixes: 5866efa8cb ("SUNRPC: Fix svcauth_gss_proxy_init()")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-08 10:51:26 -05:00
Bagas Sanjaya
df8c841dd9 NFSD: nfsd-io-modes: Separate lists
Sphinx reports htmldocs indentation warnings:

Documentation/filesystems/nfs/nfsd-io-modes.rst:58: ERROR: Unexpected indentation. [docutils]
Documentation/filesystems/nfs/nfsd-io-modes.rst:59: WARNING: Block quote ends without a blank line; unexpected unindent. [docutils]

These caused the lists to be shown as long running paragraphs merged
with their previous paragraphs.

Fix these by separating the lists with a blank line.

Fixes: fa8d4e6784 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-03 09:05:14 -05:00
Bagas Sanjaya
4fcf9952fb NFSD: nfsd-io-modes: Wrap shell snippets in literal code blocks
Sphinx reports htmldocs indentation warnings:

Documentation/filesystems/nfs/nfsd-io-modes.rst:29: ERROR: Unexpected indentation. [docutils]
Documentation/filesystems/nfs/nfsd-io-modes.rst:34: ERROR: Unexpected indentation. [docutils]

Fix these by wrapping shell snippets in literal code blocks.

Fixes: fa8d4e6784 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-03 09:05:14 -05:00
Bagas Sanjaya
21478b6eca NFSD: Add toctree entry for NFSD IO modes docs
Commit fa8d4e6784 ("NFSD: add
Documentation/filesystems/nfs/nfsd-io-modes.rst") adds documentation for
NFSD I/O modes, but it forgets to add toctree entry for it. Hence,
Sphinx reports:

Documentation/filesystems/nfs/nfsd-io-modes.rst: WARNING: document isn't included in any toctree [toc.not_included]

Add the entry.

Fixes: fa8d4e6784 ("NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20251202152506.7a2d2d41@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-03 09:05:14 -05:00
Mike Snitzer
fa8d4e6784 NFSD: add Documentation/filesystems/nfs/nfsd-io-modes.rst
This document details the NFSD IO modes that are configurable using
NFSD's experimental debugfs interfaces:

  /sys/kernel/debug/nfsd/io_cache_read
  /sys/kernel/debug/nfsd/io_cache_write

This document will evolve as NFSD's interfaces do (e.g. if/when NFSD's
debugfs interfaces are replaced with per-export controls).

Future updates will provide more specific guidance and howto
information to help others use and evaluate NFSD's IO modes:
BUFFERED, DONTCACHE and DIRECT.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-01 09:57:10 -05:00
Mike Snitzer
06c5c97293 NFSD: Implement NFSD_IO_DIRECT for NFS WRITE
When NFSD_IO_DIRECT is selected via the
/sys/kernel/debug/nfsd/io_cache_write experimental tunable, split
incoming unaligned NFS WRITE requests into a prefix, middle and
suffix segment, as needed. The middle segment is now DIO-aligned and
the prefix and/or suffix are unaligned. Synchronous buffered IO is
used for the unaligned segments, and IOCB_DIRECT is used for the
middle DIO-aligned extent.

Although IOCB_DIRECT avoids the use of the page cache, by itself it
doesn't guarantee data durability. For UNSTABLE WRITE requests,
durability is obtained by a subsequent NFS COMMIT request.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Co-developed-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-01 09:57:10 -05:00
Chuck Lever
e3e8e176ca NFSD: Make FILE_SYNC WRITEs comply with spec
Mike noted that when NFSD responds to an NFS_FILE_SYNC WRITE, it
does not also persist file time stamps. To wit, Section 18.32.3
of RFC 8881 mandates:

> The client specifies with the stable parameter the method of how
> the data is to be processed by the server. If stable is
> FILE_SYNC4, the server MUST commit the data written plus all file
> system metadata to stable storage before returning results. This
> corresponds to the NFSv2 protocol semantics. Any other behavior
> constitutes a protocol violation. If stable is DATA_SYNC4, then
> the server MUST commit all of the data to stable storage and
> enough of the metadata to retrieve the data before returning.

Commit 3f3503adb3 ("NFSD: Use vfs_iocb_iter_write()") replaced:

-		flags |= RWF_SYNC;

with:

+		kiocb.ki_flags |= IOCB_DSYNC;

which appears to be correct given:

	if (flags & RWF_SYNC)
		kiocb_flags |= IOCB_DSYNC;

in kiocb_set_rw_flags(). However the author of that commit did not
appreciate that the previous line in kiocb_set_rw_flags() results
in IOCB_SYNC also being set:

	kiocb_flags |= (__force int) (flags & RWF_SUPPORTED);

RWF_SUPPORTED contains RWF_SYNC, and RWF_SYNC is the same bit as
IOCB_SYNC. Reviewers at the time did not catch the omission.

Reported-by: Mike Snitzer <snitzer@kernel.org>
Closes: https://lore.kernel.org/linux-nfs/20251018005431.3403-1-cel@kernel.org/T/#t
Fixes: 3f3503adb3 ("NFSD: Use vfs_iocb_iter_write()")
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-12-01 09:57:10 -05:00
Dai Ngo
99f5aa14f0 NFSD: Add trace point for SCSI fencing operation.
Add trace point to print client IP address, net namespace number,
device name and status of SCSI pr_preempt command.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Dai Ngo
6f52063db9 NFSD: use correct reservation type in nfsd4_scsi_fence_client
The reservation type argument for the pr_preempt call should match the
one used in nfsd4_block_get_device_info_scsi.

Fixes: f99d4fbdae ("nfsd: add SCSI layout support")
Cc: stable@vger.kernel.org
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Chuck Lever
1c873a2fd1 xdrgen: Don't generate unnecessary semicolon
The Jinja2 templates add a semicolon at the end of every function.
The C language does not require this punctuation.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Chuck Lever
f7cb94fad4 xdrgen: Fix union declarations
Add a missing template file. This file is used when a union is
defined as a public API (ie, "pragma public <union name>;").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Olga Kornievskaia
14282cc3cf NFSD: don't start nfsd if sv_permsocks is empty
Previously, while trying to create a server instance, if no
listening sockets were present then default parameter udp
and tcp listeners were created. It's unclear what purpose
was of starting these listeners were and how this could have
been triggered by the userland setup. This patch proposed
to ensure the reverse that we never end in a situation where
no listener sockets are created and we are trying to create
nfsd threads.

The problem it solves is: when nfs.conf only has tcp=n (and
nothing else for the choice of transports), nfsdctl would
still start the server and create udp and tcp listeners.

Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Khushal Chitturi
b0f8e1f1f5 xdrgen: handle _XdrString in union encoder/decoder
Running xdrgen on xdrgen/tests/test.x fails when
generating encoder or decoder functions for union
members of type _XdrString. It was because _XdrString
does not have a spec attribute like _XdrBasic,
leading to AttributeError.

This patch updates emit_union_case_spec_definition
and emit_union_case_spec_decoder/encoder to handle
_XdrString by assigning type_name = "char *" and
avoiding referencing to spec.

Testing: Fixed xdrgen tool was run on originally failing
test file (tools/net/sunrpc/xdrgen/tests/test.x) and now
completes without AttributeError. Modified xdrgen tool was
also run against nfs4_1.x (Documentation/sunrpc/xdr/nfs4_1.x).
The output header file matches with nfs4_1.h
(include/linux/sunrpc/xdrgen/nfs4_1.h).
This validates the patch for all XDR input files currently
within the kernel.

Changes since v2:
- Moved the shebang to the first line
- Removed SPDX header to match style of current xdrgen files

Changes since v1:
- Corrected email address in Signed-off-by.
- Wrapped patch description lines to 72 characters.

Signed-off-by: Khushal Chitturi <kc9282016@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Chuck Lever
42ba5bd2e2 xdrgen: Fix the variable-length opaque field decoder template
Ensure that variable-length opaques are decoded into the named
field, and do not overwrite the structure itself.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Chuck Lever
3bd937b49a xdrgen: Make the xdrgen script location-independent
The @pythondir@ placeholder is meant for build-time substitution,
such as with autoconf. autoconf is not used in the kernel. Let's
replace that mechanism with one that better enables the xdrgen
script to be run from any directory.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Chuck Lever
75a9b40f3b xdrgen: Generalize/harden pathname construction
Use Python's built-in Path constructor to find the Jinja templates.
This provides better error checking, proper use of path component
separators, and more reliable location of the template files.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-25 09:09:42 -05:00
Jeff Layton
898f944652 lockd: don't allow locking on reexported NFSv2/3
Since commit 9254c8ae9b ("nfsd: disallow file locking and delegations
for NFSv4 reexport"), file locking when reexporting an NFS mount via
NFSv4 is expressly prohibited by nfsd. Do the same in lockd:

Add a new  nlmsvc_file_cannot_lock() helper that will test whether file
locking is allowed for a given file, and return nlm_lck_denied_nolocks
if it isn't.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-20 16:29:35 -05:00
Christoph Hellwig
f6dcad1d74 MAINTAINERS: add a nfsd blocklayout reviewer
Add a minimal entry for the block layout driver to make sure Christoph
who wrote the code gets Cced on all patches.  The actual maintenance
stays with the nfsd maintainer team.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-20 16:29:35 -05:00
Eric Biggers
78cd170d03 nfsd: Use MD5 library instead of crypto_shash
Update NFSD's support for "legacy client tracking" (which uses MD5) to
use the MD5 library instead of crypto_shash.  This has several benefits:

- Simpler code.  Notably, much of the error-handling code is no longer
  needed, since the library functions can't fail.

- Improved performance due to reduced overhead.  A microbenchmark of
  nfs4_make_rec_clidname() shows a speedup from 1455 cycles to 425.

- The MD5 code can now safely be built as a loadable module when nfsd is
  built as a loadable module.  (Previously, nfsd forced the MD5 code to
  built-in, presumably to work around the unreliability of the
  name-based loading.)  Thus select MD5 from the tristate option NFSD if
  NFSD_LEGACY_CLIENT_TRACKING, instead of from the bool option NFSD_V4.

- Fixes a bug where legacy client tracking was not supported on kernels
  booted with "fips=1", due to crypto_shash not allowing MD5 to be used.
  This particular use of MD5 is not for a cryptographic purpose, though,
  so it is acceptable even when fips=1 (see
  https://lore.kernel.org/r/dae495a93cbcc482f4ca23c3a0d9360a1fd8c3a8.camel@redhat.com/).

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-17 08:46:12 -05:00
NeilBrown
fceb8734e7 nfsd: stop pretending that we cache the SEQUENCE reply.
nfsd does not cache the reply to a SEQUENCE.  As the comment above
nfsd4_replay_cache_entry() says:

 * The sequence operation is not cached because we can use the slot and
 * session values.

The comment above nfsd4_cache_this() suggests otherwise.

 * The session reply cache only needs to cache replies that the client
 * actually asked us to.  But it's almost free for us to cache compounds
 * consisting of only a SEQUENCE op, so we may as well cache those too.
 * Also, the protocol doesn't give us a convenient response in the case
 * of a replay of a solo SEQUENCE op that wasn't cached

The code in nfsd4_store_cache_entry() makes it clear that only responses
beyond 'cstate.data_offset' are actually cached, and data_offset is set
at the end of nfsd4_encode_sequence() *after* the sequence response has
been encoded.

This patch simplifies code and removes the confusing comments.

- nfsd4_is_solo_sequence() is discarded as not-useful.
- nfsd4_cache_this() is now trivial so it too is discarded with the
  code placed in-line at the one call-site in nfsd4_store_cache_entry().
- nfsd4_enc_sequence_replay() is open-coded in to
  nfsd4_replay_cache_entry(), and then simplified to (hopefully) make
  the process of replaying a reply clearer.

Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-17 08:46:12 -05:00
Bagas Sanjaya
8320b75b2b NFS: nfsd-maintainer-entry-profile: Inline function name prefixes
Sphinx reports htmldocs warnings:

Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:185: ERROR: Unknown target name: "nfsd". [docutils]
Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:188: ERROR: Unknown target name: "nfsdn". [docutils]
Documentation/filesystems/nfs/nfsd-maintainer-entry-profile.rst:192: ERROR: Unknown target name: "nfsd4m". [docutils]

These are due to Sphinx confusing function name prefixes for external
link syntax. Fix the warnings by inlining the prefixes.

Fixes: 3a1ce35030 ("NFSD: Add a subsystem policy document")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20251117174218.29365f30@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-17 08:46:06 -05:00
Chuck Lever
3a1ce35030 NFSD: Add a subsystem policy document
Steer contributors to NFSD's patchworks instance, list our patch
submission preferences, and more. The new document is based on the
existing netdev and xfs subsystem policy documents.

This is an attempt to add transparency to the process of accepting
contributions to NFSD and getting them merged upstream.

Suggested-by: "Darrick J. Wong" <djwong@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: NeilBrown <neil@brown.name>
[ cel: Hand-edits to address review comments ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Jeff Layton
6b3b697d65 sunrpc: allocate a separate bvec array for socket sends
svc_tcp_sendmsg() calls xdr_buf_to_bvec() with the second slot of
rq_bvec as the start, but doesn't reduce the array length by one, which
could lead to an array overrun. Also, rq_bvec is always rq_maxpages in
length, which can be too short in some cases, since the TCP record
marker consumes a slot.

Fix both problems by adding a separate bvec array to the svc_sock that
is specifically for sending. For TCP, make this array one slot longer
than rq_maxpages, to account for the record marker. For UDP, only
allocate as large an array as we need since it's limited to 64k of
payload.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
ebd3330d1c SUNRPC: Improve "fragment too large" warning
Including the client IP address that generated the overrun traffic
seems like it would be helpful. The message now reads:

  kernel: svc: nfsd oversized RPC fragment (1064958 octets) from 100.64.0.11:45866

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
d686e64e93 NFSD: Implement NFSD_IO_DIRECT for NFS READ
Add an experimental option that forces NFS READ operations to use
direct I/O instead of reading through the NFS server's page cache.

There is already at least one other layer of read caching: the page
cache on NFS clients.

The server's page cache, in many cases, is unlikely to provide
additional benefit. Some benchmarks have demonstrated that the
server's page cache is actively detrimental for workloads whose
working set is larger than the server's available physical memory.

For instance, on small NFS servers, cached NFS file content can
squeeze out local memory consumers. For large sequential workloads,
an enormous amount of data flows into and out of the page cache
and is consumed by NFS clients exactly once -- caching that data
is expensive to do and totally valueless.

For now this is a hidden option that can be enabled on test
systems for benchmarking. In the longer term, this option might
be enabled persistently or per-export. When the exported file
system does not support direct I/O, NFSD falls back to using
either DONTCACHE or buffered I/O to fulfill NFS READ requests.

Suggested-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
d7de37d6d7 NFSD: Relocate the xdr_reserve_space_vec() call site
In order to detect when a direct READ is possible, we need the send
buffer's .page_len to be zero when there is nothing in the buffer's
.pages array yet.

However, when xdr_reserve_space_vec() extends the size of the
xdr_stream to accommodate a READ payload, it adds to the send
buffer's .page_len.

It should be safe to reserve the stream space /after/ the VFS read
operation completes. This is, for example, how an NFSv3 READ works:
the VFS read goes into the rq_bvec, and is then added to the send
xdr_stream later by svcxdr_encode_opaque_pages().

Now that xdr_reserve_space_vec() uses the number of bytes actually
read, the xdr_truncate_encode() call is no longer necessary.

Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Mike Snitzer
803bc849f0 NFSD: pass nfsd_file to nfsd_iter_read()
Prepare for nfsd_iter_read() to use the DIO alignment stored in
nfsd_file by passing the nfsd_file to nfsd_iter_read() rather than
just the file which is associaed with the nfsd_file.

This means nfsd4_encode_readv() now also needs the nfsd_file rather
than the file.  Instead of changing the file arg to be the nfsd_file,
we discard the file arg as the nfsd_file (and indeed the file) is
already available via the "read" argument.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Sergey Bashirov
cc6c40e09d NFSD/blocklayout: Support multiple extents per LAYOUTGET
Allow the pNFS server to respond with multiple extents to a LAYOUTGET
request, thereby avoiding unnecessary load on the server and improving
performance for the client. The number of LAYOUTGET requests is
significantly reduced for various file access patterns, including
random and parallel writes.

Additionally, this change allows the client to request layouts with the
loga_minlength value greater than the minimum possible length of a single
extent in XFS. We use this functionality to fix a livelock in the client.

Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Sergey Bashirov
0cd0d15d47 NFSD/blocklayout: Introduce layout content structure
Add a layout content structure instead of a single extent. The ability
to store and encode an array of extents is then used to implement support
for multiple extents per LAYOUTGET.

Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Sergey Bashirov
a1dce715c6 NFSD/blocklayout: Extract extent mapping from proc_layoutget
No changes in functionality. Split the proc_layoutget function to
create a helper function that maps single extent to the requested
range. This helper function is then used to implement support for
multiple extents per LAYOUTGET.

Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Sergey Bashirov
3524b021b0 NFSD/blocklayout: Fix minlength check in proc_layoutget
The extent returned by the file system may have a smaller offset than
the segment offset requested by the client. In this case, the minimum
segment length must be checked against the requested range. Otherwise,
the client may not be able to continue the read/write operation.

Fixes: 8650b8a058 ("nfsd: pNFS block layout driver")
Signed-off-by: Sergey Bashirov <sergeybashirov@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
566a414558 svcrdma: Increase the server's default RPC/RDMA credit grant
The range of commits from commit e3274026e2 ("SUNRPC: move all of
xprt handling into svc_xprt_handle()") to commit 15d39883ee
("SUNRPC: change the back-channel queue to lwq") enabled NFSD
performance to scale better as the number of nfsd threads is
increased. These commits were merged in v6.7.

Now that the nfsd thread count can scale to more threads, permit
individual clients to make more use of those threads. Increase the
RPC/RDMA per-connection credit grant from 64 to 128 -- same as the
Linux NFS client.

Simple single client fio-based benchmarking so far shows only
improvement, no regression.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
166274a245 NFSD: Update comment documenting unsupported fattr4 attributes
TIME_CREATE has been supported since commit e377a3e698 ("nfsd: Add
support for the birth time attribute").

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Matvey Kovalev
bfce8e4273 nfsd: delete unreachable confusing code in nfs4_open_delegation()
op_delegate_type is assigned OPEN_DELEGATE_NONE just before the if-block
where condition specifies it not be equal to OPEN_DELEGATE_NONE. Compiler
treats the block as unreachable and optimizes it out from the resulting
executable.

In that aspect commit d08d32e6e5 ("nfsd4: return delegation immediately
if lease fails") notably makes no difference.

Seems it's better to just drop this code instead of fiddling with memory
barriers or atomics.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Matvey Kovalev <matvey.kovalev@ispras.ru>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
ccd608e29b NFSD: Add array bounds-checking in nfsd_iter_read()
The *count parameter does not appear to be explicitly restricted
to being smaller than rsize, so it might be possible to overrun
the rq_bvec or rq_pages arrays.

Rather than overrunning these arrays (damage done!) and then WARNING
once, let's harden the loop so that it terminates before the end of
the arrays are reached. This should result in a short read, which is
OK -- clients recover by sending additional READ requests for the
remaining unread bytes.

Reported-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Jeff Layton
b5fc406bc7 nfsd: switch the default for NFSD_LEGACY_CLIENT_TRACKING to "n"
We added this Kconfig option a little over a year ago. Switch the
default to "n" in preparation for its eventual removal.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
NeilBrown
4552f4e3f2 nfsd: change nfs4_client_to_reclaim() to allocate data
The calling convention for nfs4_client_to_reclaim() is clumsy in that
the caller needs to free memory if the function fails.  It is much
cleaner if the function frees its own memory.

This patch changes nfs4_client_to_reclaim() to re-allocate the .data
fields to be stored in the newly allocated struct nfs4_client_reclaim,
and to free everything on failure.

__cld_pipe_inprogress_downcall() needs to allocate the data anyway to
copy it from user-space, so now that data is allocated twice.  I think
that is a small price to pay for a cleaner interface.

Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
NeilBrown
89bd77cf43 nfsd: move name lookup out of nfsd4_list_rec_dir()
nfsd4_list_rec_dir() is called with two different callbacks.
One of the callbacks uses vfs_rmdir() to remove the directory.
The other doesn't use the dentry at all, just the name.

As only one callback needs the dentry, this patch moves the lookup into
that callback.  This prepares of changes to how directory operations
are locked.

Signed-off-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Chuck Lever
bf94dea7fd svcrdma: Release transport resources synchronously
NFSD has always supported added network listeners. The new netlink
protocol now enables the removal of listeners.

Olga noticed that if an RDMA listener is removed and immediately
re-added, the deferred __svc_rdma_free() function might not have
run yet, so some or all of the old listener's RDMA resources
linger, which prevents a new listener on the same address from
being created.

Also, svc_xprt_free() does a module_put() just after calling
->xpo_free(). That means if there is deferred work going on, the
module could be unloaded before that work is even started,
resulting in a UAF.

Neil asks:
> What particular part of __svc_rdma_free() needs to run in order for a
> subsequent registration to succeed?
> Can that bit be run directory from svc_rdma_free() rather than be
> delayed?
> (I know almost nothing about rdma so forgive me if the answers to these
> questions seems obvious)

The reasons I can recall are:

 - Some of the transport tear-down work can sleep
 - Releasing a cm_id is tricky and can deadlock

We might be able to mitigate the second issue with judicious
application of transport reference counting.

Reported-by: Olga Kornievskaia <okorniev@redhat.com>
Closes: https://lore.kernel.org/linux-nfs/20250821204328.89218-1-okorniev@redhat.com/
Suggested-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2025-11-16 18:20:11 -05:00
Linus Torvalds
6a23ae0a96 Linux 6.18-rc6 2025-11-16 14:25:38 -08:00
Linus Torvalds
998ccc327b perf tools fixes for v6.18: 2nd batch
- Fix writing bpf_prog (infos|btfs)_cnt to data file, to not generate
   invalid perf.data files in some corner cases.
 
 - Fix 'perf top' segfault by ensuring libbfd is initialized. This is an
   opt-in feature due to license incompatibilities.
 
 - Fix segfault in 'perf lock' due to missing kernel map.
 
 - Fix 'perf lock contention' test.
 
 - Don't fail fast path detection if binutils-devel isn't available.
 
 - Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-fixes-for-v6.18-2-2025-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix writing bpf_prog (infos|btfs)_cnt to data file, to not generate
   invalid perf.data files in some corner cases.

 - Fix 'perf top' segfault by ensuring libbfd is initialized. This is an
   opt-in feature due to license incompatibilities.

 - Fix segfault in 'perf lock' due to missing kernel map.

 - Fix 'perf lock contention' test.

 - Don't fail fast path detection if binutils-devel isn't available.

 - Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason.

* tag 'perf-tools-fixes-for-v6.18-2-2025-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools:
  perf libbfd: Ensure libbfd is initialized prior to use
  perf test: Fix lock contention test
  perf lock: Fix segfault due to missing kernel map
  tools headers UAPI: Sync KVM's vmx.h with the kernel to pick SEAMCALL exit reason
  perf build: Don't fail fast path feature detection when binutils-devel is not available
  perf header: Write bpf_prog (infos|btfs)_cnt to data file
2025-11-16 13:45:03 -08:00
Linus Torvalds
7ba45f1504 7 hotfixes. 5 are cc:stable, 4 are against mm/.
All are singletons - please see the respective changelogs for details.
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Merge tag 'mm-hotfixes-stable-2025-11-16-10-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "7 hotfixes.  5 are cc:stable, 4 are against mm/

  All are singletons - please see the respective changelogs for details"

* tag 'mm-hotfixes-stable-2025-11-16-10-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm, swap: fix potential UAF issue for VMA readahead
  selftests/user_events: fix type cast for write_index packed member in perf_test
  lib/test_kho: check if KHO is enabled
  mm/huge_memory: fix folio split check for anon folios in swapcache
  MAINTAINERS: update David Hildenbrand's email address
  crash: fix crashkernel resource shrink
  mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb
2025-11-16 13:31:14 -08:00
Linus Torvalds
7254a2b522 firewire fixes for 6.18-rc6
This includes some fixes for bugs to generate topology map, newly
 introduced in v6.18 kernel.
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Merge tag 'firewire-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire fixes from Takashi Sakamoto:
 "This includes some fixes for the topology map, newly introduced in
  v6.18 kernel"

* tag 'firewire-fixes-6.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  firewire: core: fix to update generation field in topology map
  firewire: core: Initialize topology_map.lock
2025-11-16 07:08:28 -08:00