[GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[Anna Schumaker]

Hi Linus,

The following changes since commit 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7:

  Linux 6.19-rc6 (2026-01-18 15:42:45 -0800)

are available in the Git repository at:

  git://git.linux-nfs.org/projects/anna/linux-nfs.git tags/nfs-for-7.0-1

for you to fetch changes up to dd2fdc3504592d85e549c523b054898a036a6afe:

  SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path (2026-02-09 16:39:50 -0500)

----------------------------------------------------------------
NFS Client Updates for Linux 7.0

New Features:
 * Use an LRU list for returning unused delegations
 * Introduce a KConfig option to disable NFS v4.0 and make NFS v4.1 the default

Bugfixes:
 * NFS/localio: Handle short writes by retrying
 * NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
 * NFS/localio: use GFP_NOIO and non-memreclaim workqueue in nfs_local_commit
 * NFS/localio: remove -EAGAIN handling in nfs_local_doio()
 * pNFS: fix a missing wake up while waiting on NFS_LAYOUT_DRAIN
 * fs/nfs: Fix a readdir slow-start regression
 * SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path

Other Cleanups and Improvements:
  * A few other NFS/localio cleanups
  * Various other delegation handling cleanups from Christoph
  * Unify security_inode_listsecurity() calls
  * Improvements to NFSv4 lease handling
  * Clean up SUNRPC *_debug fields when CONFIG_SUNRPC_DEBUG is not set

Thanks,
Anna

----------------------------------------------------------------
Anna Schumaker (14):
      NFS: Move nfs40_call_sync_ops into nfs40proc.c
      NFS: Split out the nfs40_reboot_recovery_ops into nfs40client.c
      NFS: Split out the nfs40_nograce_recovery_ops into nfs40proc.c
      NFS: Split out the nfs40_state_renewal_ops into nfs40proc.c
      NFS: Split out the nfs40_mig_recovery_ops to nfs40proc.c
      NFS: Move the NFS v4.0 minor version ops into nfs40proc.c
      NFS: Make the various NFS v4.0 operations static again
      NFS: Move nfs40_shutdown_client into nfs40client.c
      NFS: Move nfs40_init_client into nfs40client.c
      NFS: Move NFS v4.0 pathdown recovery into nfs40client.c
      NFS: Pass a struct nfs_client to nfs4_init_sequence()
      NFS: Move sequence slot operations into minorversion operations
      NFS: Add a way to disable NFS v4.0 via KConfig
      NFS: Merge CONFIG_NFS_V4_1 with CONFIG_NFS_V4

Ben Dooks (1):
      sunrpc: rpc_debug and others are defined even if CONFIG_SUNRPC_DEBUG unset

Chen Ni (1):
      nfs: nfs4proc: Convert comma to semicolon

Chenguang Zhao (1):
      SUNRPC: Change list definition method

Christoph Hellwig (31):
      NFS: remove __nfs_client_for_each_server
      NFS: remove nfs_client_mark_return_unused_delegation_types
      NFS: remove nfs_client_mark_return_all_delegations
      NFS: remove the NULL inode check in nfs4_inode_return_delegation_on_close
      NFS: remove nfs_inode_detach_delegation
      NFS: remove nfs_start_delegation_return
      NFS: assert rcu_read_lock is held in nfs_start_delegation_return_locked
      NFS: drop the _locked postfix from nfs_start_delegation_return
      NFS: remove NFS_DELEGATION_INODE_FREEING
      NFS: open code nfs_delegation_need_return
      NFS: remove nfs_free_delegation
      NFS: rewrite nfs_delegations_present in terms of nr_active_delegations
      NFS: move delegation lookup into can_open_delegated
      NFS: return bool from nfs_detach_delegation{,_locked}
      NFS: move the deleg_cur check out of nfs_detach_delegation_locked
      NFS: simplify the detached delegation check in update_open_stateid
      NFS: take a delegation reference in nfs4_get_valid_delegation
      NFS: don't consume a delegation reference in nfs_end_delegation_return
      NFS: use refcount_inc_not_zero nfs_start_delegation_return
      NFS: use a local RCU critical section in nfs_start_delegation_return
      NFS: reformat nfs_mark_delegation_revoked
      NFS: add a separate delegation return list
      NFS: return delegations from the end of a LRU when over the watermark
      NFS: make nfs_mark_return_unreferenced_delegations less aggressive
      NFS: return void from nfs4_inode_make_writeable
      NFS: return void from ->return_delegation
      NFS: use bool for the issync argument to nfs_end_delegation_return
      NFS: remove the delegation == NULL check in nfs_end_delegation_return
      NFS: fold nfs_abort_delegation_return into nfs_end_delegation_return
      NFS: simplify error handling in nfs_end_delegation_return
      NFS: fix delayed delegation return handling

Daniel Hodges (1):
      SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path

Mike Snitzer (4):
      NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
      NFS/localio: use GFP_NOIO and non-memreclaim workqueue in nfs_local_commit
      NFS/localio: remove -EAGAIN handling in nfs_local_doio()
      NFS/localio: switch nfs_local_do_read and nfs_local_do_write to return void

Olga Kornievskaia (1):
      pNFS: fix a missing wake up while waiting on NFS_LAYOUT_DRAIN

Sagi Grimberg (1):
      fs/nfs: Fix readdir slow-start regression

Sergey Shtylyov (2):
      NFSv4: pass lease period in seconds to nfs4_set_lease_period()
      NFSv4: limit lease period in nfs4_set_lease_period()

Stephen Smalley (1):
      nfs: unify security_inode_listsecurity() calls

Trond Myklebust (2):
      NFS/localio: Handle short writes by retrying
      NFS/localio: Cleanup the nfs_local_pgio_done() parameters

 fs/nfs/Kconfig                 |  26 +-
 fs/nfs/Makefile                |   4 +-
 fs/nfs/callback.c              |  13 +-
 fs/nfs/callback.h              |   3 -
 fs/nfs/callback_proc.c         |  16 +-
 fs/nfs/callback_xdr.c          |  21 --
 fs/nfs/client.c                |  12 +-
 fs/nfs/delegation.c            | 594 +++++++++++++++---------------
 fs/nfs/delegation.h            |   9 +-
 fs/nfs/dir.c                   |   4 +-
 fs/nfs/fs_context.c            |   3 +-
 fs/nfs/internal.h              |  15 +-
 fs/nfs/localio.c               | 126 ++++---
 fs/nfs/netns.h                 |   4 +-
 fs/nfs/nfs3proc.c              |   3 +-
 fs/nfs/nfs40.h                 |  19 +
 fs/nfs/nfs40client.c           | 245 +++++++++++++
 fs/nfs/nfs40proc.c             | 395 ++++++++++++++++++++
 fs/nfs/nfs42proc.c             |  13 +-
 fs/nfs/nfs4_fs.h               |  86 +++--
 fs/nfs/nfs4client.c            | 193 +---------
 fs/nfs/nfs4proc.c              | 804 +++++++++--------------------------------
 fs/nfs/nfs4renewd.c            |  15 +-
 fs/nfs/nfs4session.c           |   4 -
 fs/nfs/nfs4session.h           |  23 --
 fs/nfs/nfs4state.c             |  93 +----
 fs/nfs/nfs4trace.c             |   2 -
 fs/nfs/nfs4trace.h             |  21 +-
 fs/nfs/nfs4xdr.c               | 109 ++----
 fs/nfs/pnfs.c                  |   3 +-
 fs/nfs/pnfs.h                  |   6 +-
 fs/nfs/proc.c                  |   3 +-
 fs/nfs/read.c                  |   4 +-
 fs/nfs/super.c                 |  30 +-
 fs/nfs/sysfs.c                 |  10 +-
 fs/nfs/write.c                 |   2 +-
 include/linux/nfs_fs_sb.h      |  10 +-
 include/linux/nfs_xdr.h        |   9 +-
 include/linux/sunrpc/debug.h   |   2 -
 net/sunrpc/auth_gss/auth_gss.c |   3 +
 net/sunrpc/backchannel_rqst.c  |   3 +-
 41 files changed, 1372 insertions(+), 1588 deletions(-)
 create mode 100644 fs/nfs/nfs40.h
 create mode 100644 fs/nfs/nfs40client.c
 create mode 100644 fs/nfs/nfs40proc.c

Re: [GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[pr-tracker-bot]

The pull request you sent on Thu, 12 Feb 2026 17:06:25 -0500:

> git://git.linux-nfs.org/projects/anna/linux-nfs.git tags/nfs-for-7.0-1

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/7449f86bafcdb588422bb14a4babfd285e723670

Thank you!

-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/prtracker.html

Re: [GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[Niklas Cassel]

On Thu, Feb 12, 2026 at 05:06:25PM -0500, Anna Schumaker wrote:
> Hi Linus,
> 
> The following changes since commit 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7:
> 
>   Linux 6.19-rc6 (2026-01-18 15:42:45 -0800)
> 
> are available in the Git repository at:
> 
>   git://git.linux-nfs.org/projects/anna/linux-nfs.git tags/nfs-for-7.0-1
> 
> for you to fetch changes up to dd2fdc3504592d85e549c523b054898a036a6afe:
> 
>   SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path (2026-02-09 16:39:50 -0500)
> 
> ----------------------------------------------------------------
> NFS Client Updates for Linux 7.0
> 
> New Features:
>  * Use an LRU list for returning unused delegations
>  * Introduce a KConfig option to disable NFS v4.0 and make NFS v4.1 the default
> 
> Bugfixes:
>  * NFS/localio: Handle short writes by retrying
>  * NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
>  * NFS/localio: use GFP_NOIO and non-memreclaim workqueue in nfs_local_commit
>  * NFS/localio: remove -EAGAIN handling in nfs_local_doio()
>  * pNFS: fix a missing wake up while waiting on NFS_LAYOUT_DRAIN
>  * fs/nfs: Fix a readdir slow-start regression
>  * SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path
> 
> Other Cleanups and Improvements:
>   * A few other NFS/localio cleanups
>   * Various other delegation handling cleanups from Christoph
>   * Unify security_inode_listsecurity() calls
>   * Improvements to NFSv4 lease handling
>   * Clean up SUNRPC *_debug fields when CONFIG_SUNRPC_DEBUG is not set
> 
> Thanks,
> Anna

Hello Anna,

This seems to break my setup:

[  103.402033] VFS: Unable to mount root fs via NFS.
[  103.402476] devtmpfs: mounted
[  103.406171] Freeing unused kernel memory: 4352K
[  103.406633] Run /sbin/init as init process
[  103.406993]   with arguments:
[  103.407253]     /sbin/init
[  103.407491]   with environment:
[  103.407767]     HOME=/
[  103.407976]     TERM=linux
[  103.408228] Run /etc/init as init process
[  103.408580]   with arguments:
[  103.408841]     /etc/init
[  103.409071]   with environment:
[  103.409346]     HOME=/
[  103.409553]     TERM=linux
[  103.409802] Run /bin/init as init process
[  103.410153]   with arguments:
[  103.410414]     /bin/init
[  103.410644]   with environment:
[  103.410920]     HOME=/
[  103.411128]     TERM=linux
[  103.411367] Run /bin/sh as init process
[  103.411703]   with arguments:
[  103.411963]     /bin/sh
[  103.412179]   with environment:
[  103.412454]     HOME=/
[  103.412662]     TERM=linux
[  103.412904] Kernel panic - not syncing: No working init found.  Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance.


Doing a git bisect results in:

commit 4e0269352534715915aae3fb84dd4d3bb3ff3738
Author: Anna Schumaker <anna.schumaker@oracle.com>
Date:   Fri Nov 21 14:53:50 2025 -0500

    NFS: Add a way to disable NFS v4.0 via KConfig

    I introduce NFS4_MIN_MINOR_VERSION as a parallel to
    NFS4_MAX_MINOR_VERSION to check if NFS v4.0 has been compiled in and
    return an appropriate error if not.



Before commit above my config has:
CONFIG_NFS_FS=y
CONFIG_NFS_V4=y
CONFIG_NFS_V4_1=y
CONFIG_NFS_V4_2=y

after commit above (with make olddefconfig), my config has:
CONFIG_NFS_FS=y
CONFIG_NFS_V4=y
# CONFIG_NFS_V4_0 is not set
CONFIG_NFS_V4_1=y
CONFIG_NFS_V4_2=y



My kernel command line has:
nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4


I notice that I am probably stupid who has the above, as I assumed that
it meant use the best NFS 4.x version supported by the kernel.


If I change it to:
nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4.2

The config:
CONFIG_NFS_FS=y
CONFIG_NFS_V4=y
# CONFIG_NFS_V4_0 is not set
CONFIG_NFS_V4_1=y
CONFIG_NFS_V4_2=y

successfully mounts my rootfs.


So AFAICT, it seems that nfsvers=4 actually means nfsvers=4.0

I am probably not the only person to who has "nfsvers=4" on the kernel
command line.



Possible solutions I can see:

If the intention is for commit 4e0269352534 ("NFS: Add a way to disable
NFS v4.0 via KConfig") to allow people to disable NFS 4.0, we could
change the new "config NFS_V4_0" to be either "default y".

or

Perhaps we could modify "nfsvers=4" to actually mean "use whatever highest
NFS 4.x version supported by the kernel", rather than use NFS 4.0 and only
4.0.



Kind regards,
Niklas

Re: [GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[Anna Schumaker]

On Mon, Feb 16, 2026, at 10:31 AM, Niklas Cassel wrote:
> On Thu, Feb 12, 2026 at 05:06:25PM -0500, Anna Schumaker wrote:
>> Hi Linus,
>> 
>> The following changes since commit 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7:
>> 
>>   Linux 6.19-rc6 (2026-01-18 15:42:45 -0800)
>> 
>> are available in the Git repository at:
>> 
>>   git://git.linux-nfs.org/projects/anna/linux-nfs.git tags/nfs-for-7.0-1
>> 
>> for you to fetch changes up to dd2fdc3504592d85e549c523b054898a036a6afe:
>> 
>>   SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path (2026-02-09 16:39:50 -0500)
>> 
>> ----------------------------------------------------------------
>> NFS Client Updates for Linux 7.0
>> 
>> New Features:
>>  * Use an LRU list for returning unused delegations
>>  * Introduce a KConfig option to disable NFS v4.0 and make NFS v4.1 the default
>> 
>> Bugfixes:
>>  * NFS/localio: Handle short writes by retrying
>>  * NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
>>  * NFS/localio: use GFP_NOIO and non-memreclaim workqueue in nfs_local_commit
>>  * NFS/localio: remove -EAGAIN handling in nfs_local_doio()
>>  * pNFS: fix a missing wake up while waiting on NFS_LAYOUT_DRAIN
>>  * fs/nfs: Fix a readdir slow-start regression
>>  * SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path
>> 
>> Other Cleanups and Improvements:
>>   * A few other NFS/localio cleanups
>>   * Various other delegation handling cleanups from Christoph
>>   * Unify security_inode_listsecurity() calls
>>   * Improvements to NFSv4 lease handling
>>   * Clean up SUNRPC *_debug fields when CONFIG_SUNRPC_DEBUG is not set
>> 
>> Thanks,
>> Anna
>
> Hello Anna,
>
> This seems to break my setup:
>
> [  103.402033] VFS: Unable to mount root fs via NFS.
> [  103.402476] devtmpfs: mounted
> [  103.406171] Freeing unused kernel memory: 4352K
> [  103.406633] Run /sbin/init as init process
> [  103.406993]   with arguments:
> [  103.407253]     /sbin/init
> [  103.407491]   with environment:
> [  103.407767]     HOME=/
> [  103.407976]     TERM=linux
> [  103.408228] Run /etc/init as init process
> [  103.408580]   with arguments:
> [  103.408841]     /etc/init
> [  103.409071]   with environment:
> [  103.409346]     HOME=/
> [  103.409553]     TERM=linux
> [  103.409802] Run /bin/init as init process
> [  103.410153]   with arguments:
> [  103.410414]     /bin/init
> [  103.410644]   with environment:
> [  103.410920]     HOME=/
> [  103.411128]     TERM=linux
> [  103.411367] Run /bin/sh as init process
> [  103.411703]   with arguments:
> [  103.411963]     /bin/sh
> [  103.412179]   with environment:
> [  103.412454]     HOME=/
> [  103.412662]     TERM=linux
> [  103.412904] Kernel panic - not syncing: No working init found.  Try 
> passing init= option to kernel. See Linux 
> Documentation/admin-guide/init.rst for guidance.
>
>
> Doing a git bisect results in:
>
> commit 4e0269352534715915aae3fb84dd4d3bb3ff3738
> Author: Anna Schumaker <anna.schumaker@oracle.com>
> Date:   Fri Nov 21 14:53:50 2025 -0500
>
>     NFS: Add a way to disable NFS v4.0 via KConfig
>
>     I introduce NFS4_MIN_MINOR_VERSION as a parallel to
>     NFS4_MAX_MINOR_VERSION to check if NFS v4.0 has been compiled in and
>     return an appropriate error if not.
>
>
>
> Before commit above my config has:
> CONFIG_NFS_FS=y
> CONFIG_NFS_V4=y
> CONFIG_NFS_V4_1=y
> CONFIG_NFS_V4_2=y
>
> after commit above (with make olddefconfig), my config has:
> CONFIG_NFS_FS=y
> CONFIG_NFS_V4=y
> # CONFIG_NFS_V4_0 is not set
> CONFIG_NFS_V4_1=y
> CONFIG_NFS_V4_2=y
>
>
>
> My kernel command line has:
> nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4
>
>
> I notice that I am probably stupid who has the above, as I assumed that
> it meant use the best NFS 4.x version supported by the kernel.
>
>
> If I change it to:
> nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4.2
>
> The config:
> CONFIG_NFS_FS=y
> CONFIG_NFS_V4=y
> # CONFIG_NFS_V4_0 is not set
> CONFIG_NFS_V4_1=y
> CONFIG_NFS_V4_2=y
>
> successfully mounts my rootfs.
>
>
> So AFAICT, it seems that nfsvers=4 actually means nfsvers=4.0
>
> I am probably not the only person to who has "nfsvers=4" on the kernel
> command line.
>
>
>
> Possible solutions I can see:
>
> If the intention is for commit 4e0269352534 ("NFS: Add a way to disable
> NFS v4.0 via KConfig") to allow people to disable NFS 4.0, we could
> change the new "config NFS_V4_0" to be either "default y".

This is what I intended, actually. I don't know how the missing "default y"
slipped through the cracks for this long. Thanks for pointing it out, I'll
get this fixed up!

Anna

>
> or
>
> Perhaps we could modify "nfsvers=4" to actually mean "use whatever highest
> NFS 4.x version supported by the kernel", rather than use NFS 4.0 and only
> 4.0.
>
>
>
> Kind regards,
> Niklas

Re: [GIT PULL] Please Pull NFS Client Updates for Linux 7.0

[Mike Snitzer]

On Wed, Feb 18, 2026 at 11:24:42AM -0500, Anna Schumaker wrote:
> 
> 
> On Mon, Feb 16, 2026, at 10:31 AM, Niklas Cassel wrote:
> > On Thu, Feb 12, 2026 at 05:06:25PM -0500, Anna Schumaker wrote:
> >> Hi Linus,
> >> 
> >> The following changes since commit 24d479d26b25bce5faea3ddd9fa8f3a6c3129ea7:
> >> 
> >>   Linux 6.19-rc6 (2026-01-18 15:42:45 -0800)
> >> 
> >> are available in the Git repository at:
> >> 
> >>   git://git.linux-nfs.org/projects/anna/linux-nfs.git tags/nfs-for-7.0-1
> >> 
> >> for you to fetch changes up to dd2fdc3504592d85e549c523b054898a036a6afe:
> >> 
> >>   SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path (2026-02-09 16:39:50 -0500)
> >> 
> >> ----------------------------------------------------------------
> >> NFS Client Updates for Linux 7.0
> >> 
> >> New Features:
> >>  * Use an LRU list for returning unused delegations
> >>  * Introduce a KConfig option to disable NFS v4.0 and make NFS v4.1 the default
> >> 
> >> Bugfixes:
> >>  * NFS/localio: Handle short writes by retrying
> >>  * NFS/localio: prevent direct reclaim recursion into NFS via nfs_writepages
> >>  * NFS/localio: use GFP_NOIO and non-memreclaim workqueue in nfs_local_commit
> >>  * NFS/localio: remove -EAGAIN handling in nfs_local_doio()
> >>  * pNFS: fix a missing wake up while waiting on NFS_LAYOUT_DRAIN
> >>  * fs/nfs: Fix a readdir slow-start regression
> >>  * SUNRPC: fix gss_auth kref leak in gss_alloc_msg error path
> >> 
> >> Other Cleanups and Improvements:
> >>   * A few other NFS/localio cleanups
> >>   * Various other delegation handling cleanups from Christoph
> >>   * Unify security_inode_listsecurity() calls
> >>   * Improvements to NFSv4 lease handling
> >>   * Clean up SUNRPC *_debug fields when CONFIG_SUNRPC_DEBUG is not set
> >> 
> >> Thanks,
> >> Anna
> >
> > Hello Anna,
> >
> > This seems to break my setup:
> >
> > [  103.402033] VFS: Unable to mount root fs via NFS.
> > [  103.402476] devtmpfs: mounted
> > [  103.406171] Freeing unused kernel memory: 4352K
> > [  103.406633] Run /sbin/init as init process
> > [  103.406993]   with arguments:
> > [  103.407253]     /sbin/init
> > [  103.407491]   with environment:
> > [  103.407767]     HOME=/
> > [  103.407976]     TERM=linux
> > [  103.408228] Run /etc/init as init process
> > [  103.408580]   with arguments:
> > [  103.408841]     /etc/init
> > [  103.409071]   with environment:
> > [  103.409346]     HOME=/
> > [  103.409553]     TERM=linux
> > [  103.409802] Run /bin/init as init process
> > [  103.410153]   with arguments:
> > [  103.410414]     /bin/init
> > [  103.410644]   with environment:
> > [  103.410920]     HOME=/
> > [  103.411128]     TERM=linux
> > [  103.411367] Run /bin/sh as init process
> > [  103.411703]   with arguments:
> > [  103.411963]     /bin/sh
> > [  103.412179]   with environment:
> > [  103.412454]     HOME=/
> > [  103.412662]     TERM=linux
> > [  103.412904] Kernel panic - not syncing: No working init found.  Try 
> > passing init= option to kernel. See Linux 
> > Documentation/admin-guide/init.rst for guidance.
> >
> >
> > Doing a git bisect results in:
> >
> > commit 4e0269352534715915aae3fb84dd4d3bb3ff3738
> > Author: Anna Schumaker <anna.schumaker@oracle.com>
> > Date:   Fri Nov 21 14:53:50 2025 -0500
> >
> >     NFS: Add a way to disable NFS v4.0 via KConfig
> >
> >     I introduce NFS4_MIN_MINOR_VERSION as a parallel to
> >     NFS4_MAX_MINOR_VERSION to check if NFS v4.0 has been compiled in and
> >     return an appropriate error if not.
> >
> >
> >
> > Before commit above my config has:
> > CONFIG_NFS_FS=y
> > CONFIG_NFS_V4=y
> > CONFIG_NFS_V4_1=y
> > CONFIG_NFS_V4_2=y
> >
> > after commit above (with make olddefconfig), my config has:
> > CONFIG_NFS_FS=y
> > CONFIG_NFS_V4=y
> > # CONFIG_NFS_V4_0 is not set
> > CONFIG_NFS_V4_1=y
> > CONFIG_NFS_V4_2=y
> >
> >
> >
> > My kernel command line has:
> > nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4
> >
> >
> > I notice that I am probably stupid who has the above, as I assumed that
> > it meant use the best NFS 4.x version supported by the kernel.
> >
> >
> > If I change it to:
> > nfsroot=192.168.1.10:/srv/nfs/rootfs,nfsvers=4.2
> >
> > The config:
> > CONFIG_NFS_FS=y
> > CONFIG_NFS_V4=y
> > # CONFIG_NFS_V4_0 is not set
> > CONFIG_NFS_V4_1=y
> > CONFIG_NFS_V4_2=y
> >
> > successfully mounts my rootfs.
> >
> >
> > So AFAICT, it seems that nfsvers=4 actually means nfsvers=4.0
> >
> > I am probably not the only person to who has "nfsvers=4" on the kernel
> > command line.
> >
> >
> >
> > Possible solutions I can see:
> >
> > If the intention is for commit 4e0269352534 ("NFS: Add a way to disable
> > NFS v4.0 via KConfig") to allow people to disable NFS 4.0, we could
> > change the new "config NFS_V4_0" to be either "default y".
> 
> This is what I intended, actually. I don't know how the missing "default y"
> slipped through the cracks for this long. Thanks for pointing it out, I'll
> get this fixed up!
> 
> Anna
> 
> >
> > or
> >
> > Perhaps we could modify "nfsvers=4" to actually mean "use whatever highest
> > NFS 4.x version supported by the kernel", rather than use NFS 4.0 and only
> > 4.0.

Another related problem I just encountered, when doing a bisect that
pivoted from 7.0-rc1 back down to 6.19, is that "make olddefconfig"
using the 7.0-rc1's .config as starting point against 6.19 kernel
results in:

# CONFIG_NFS_V4_1 is not set
# CONFIG_NFS_V4_2 is not set

CONFIG_PNFS_FLEXFILE_LAYOUT=m doesn't exist, etc.  So this change
seriously breaks NFS bisect-ability.

Feels like the new CONFIG_NFS_V4_0 control should be standalone and
CONFIG_NFS_V4_1 shouldn't be removed. But the devil is in the details
I'm sure...

Mike