nfsd: drop the nfsd_put helper

commit 64e6304169f1e1f078e7f0798033f80a7fb0ea46 upstream.

It's not safe to call nfsd_put once nfsd_last_thread has been called, as
that function will zero out the nn-

nfsd: drop the nfsd_put helper

commit 64e6304169f1e1f078e7f0798033f80a7fb0ea46 upstream.

It's not safe to call nfsd_put once nfsd_last_thread has been called, as
that function will zero out the nn->nfsd_serv pointer.

Drop the nfsd_put helper altogether and open-code the svc_put in its
callers instead. That allows us to not be reliant on the value of that
pointer when handling an error.

Fixes: 2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()")
Reported-by: Zhi Li <yieli@redhat.com>
Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Jeffrey Layton <jlayton@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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nfsd: call nfsd_last_thread() before final nfsd_put()

commit 2a501f55cd641eb4d3c16a2eab0d678693fac663 upstream.

If write_ports_addfd or write_ports_addxprt fail, they call nfsd_put()
without callin

nfsd: call nfsd_last_thread() before final nfsd_put()

commit 2a501f55cd641eb4d3c16a2eab0d678693fac663 upstream.

If write_ports_addfd or write_ports_addxprt fail, they call nfsd_put()
without calling nfsd_last_thread(). This leaves nn->nfsd_serv pointing
to a structure that has been freed.

So remove 'static' from nfsd_last_thread() and call it when the
nfsd_serv is about to be destroyed.

Fixes: ec52361df99b ("SUNRPC: stop using ->sv_nrthreads as a refcount")
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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nfsd: add a MODULE_DESCRIPTION

I got this today from modpost:

WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nfsd/nfsd.o

Add a module description.

Signed-off-by: Jeff Layton <jlayton@ke

nfsd: add a MODULE_DESCRIPTION

I got this today from modpost:

WARNING: modpost: missing MODULE_DESCRIPTION() in fs/nfsd/nfsd.o

Add a module description.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: Fix a thinko introduced by recent trace point changes

The fixed commit erroneously removed a call to nfsd_end_grace(),
which makes calls to write_v4_end_grace() a no-op.

Reported-by: kernel t

NFSD: Fix a thinko introduced by recent trace point changes

The fixed commit erroneously removed a call to nfsd_end_grace(),
which makes calls to write_v4_end_grace() a no-op.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202308241229.68396422-oliver.sang@intel.com
Fixes: 39d432fc7630 ("NFSD: trace nfsctl operations")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

nfsd: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-56-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

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NFSD: Distinguish per-net namespace initialization

I find the naming of nfsd_init_net() and nfsd_startup_net() to be
confusingly similar. Rename the namespace initialization and tear-
down ops and a

NFSD: Distinguish per-net namespace initialization

I find the naming of nfsd_init_net() and nfsd_startup_net() to be
confusingly similar. Rename the namespace initialization and tear-
down ops and add comments to distinguish their separate purposes.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net

Commit f5f9d4a314da ("nfsd: move reply cache initialization into nfsd
startup") moved the initialization of the reply cache

nfsd: move init of percpu reply_cache_stats counters back to nfsd_init_net

Commit f5f9d4a314da ("nfsd: move reply cache initialization into nfsd
startup") moved the initialization of the reply cache into nfsd startup,
but didn't account for the stats counters, which can be accessed before
nfsd is ever started. The result can be a NULL pointer dereference when
someone accesses /proc/fs/nfsd/reply_cache_stats while nfsd is still
shut down.

This is a regression and a user-triggerable oops in the right situation:

- non-x86_64 arch
- /proc/fs/nfsd is mounted in the namespace
- nfsd is not started in the namespace
- unprivileged user calls "cat /proc/fs/nfsd/reply_cache_stats"

Although this is easy to trigger on some arches (like aarch64), on
x86_64, calling this_cpu_ptr(NULL) evidently returns a pointer to the
fixed_percpu_data. That struct looks just enough like a newly
initialized percpu var to allow nfsd_reply_cache_stats_show to access
it without Oopsing.

Move the initialization of the per-net+per-cpu reply-cache counters
back into nfsd_init_net, while leaving the rest of the reply cache
allocations to be done at nfsd startup time.

Kudos to Eirik who did most of the legwork to track this down.

Cc: stable@vger.kernel.org # v6.3+
Fixes: f5f9d4a314da ("nfsd: move reply cache initialization into nfsd startup")
Reported-and-tested-by: Eirik Fuller <efuller@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2215429
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: trace nfsctl operations

Add trace log eye-catchers that record the arguments used to
configure NFSD. This helps when troubleshooting the NFSD
administrative interfaces.

These tracepoints can

NFSD: trace nfsctl operations

Add trace log eye-catchers that record the arguments used to
configure NFSD. This helps when troubleshooting the NFSD
administrative interfaces.

These tracepoints can capture NFSD start-up and shutdown times and
parameters, changes in lease time and thread count, and a request
to end the namespace's NFSv4 grace period, in addition to the set
of NFS versions that are enabled.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: Clean up nfsctl_transaction_write()

For easier readability, follow the common convention:

if (error)
handle_error;
continue_normally;

No behavior change is expected.

Reviewed-by: J

NFSD: Clean up nfsctl_transaction_write()

For easier readability, follow the common convention:

if (error)
handle_error;
continue_normally;

No behavior change is expected.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: Clean up nfsctl white-space damage

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

nfsd: fix double fget() bug in __write_ports_addfd()

The bug here is that you cannot rely on getting the same socket
from multiple calls to fget() because userspace can influence
that. This is a ki

nfsd: fix double fget() bug in __write_ports_addfd()

The bug here is that you cannot rely on getting the same socket
from multiple calls to fget() because userspace can influence
that. This is a kind of double fetch bug.

The fix is to delete the svc_alien_sock() function and instead do
the checking inside the svc_addsock() function.

Fixes: 3064639423c4 ("nfsd: check passed socket's net matches NFSd superblock's one")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: define exports_proc_ops with CONFIG_PROC_FS

gcc with W=1 and ! CONFIG_PROC_FS
fs/nfsd/nfsctl.c:161:30: error: ‘exports_proc_ops’
defined but not used [-Werror=unused-const-variable=]
161 |

nfsd: define exports_proc_ops with CONFIG_PROC_FS

gcc with W=1 and ! CONFIG_PROC_FS
fs/nfsd/nfsctl.c:161:30: error: ‘exports_proc_ops’
defined but not used [-Werror=unused-const-variable=]
161 | static const struct proc_ops exports_proc_ops = {
| ^~~~~~~~~~~~~~~~

The only use of exports_proc_ops is when CONFIG_PROC_FS
is defined, so its definition should be likewise conditional.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: Clean up nfsd_symlink()

The pointer dentry is assigned a value that is never read, the
assignment is redundant and can be removed.

Cleans up clang-scan warning:
fs/nfsd/nfsctl.c:1231:2: warni

NFSD: Clean up nfsd_symlink()

The pointer dentry is assigned a value that is never read, the
assignment is redundant and can be removed.

Cleans up clang-scan warning:
fs/nfsd/nfsctl.c:1231:2: warning: Value stored to 'dentry' is
never read [deadcode.DeadStores]
dentry = ERR_PTR(ret);

No need to initialize "int ret = -ENOMEM;" either.

These are vestiges of nfsd_mkdir(), from whence I copied
nfsd_symlink().

Reported-by: Colin Ian King <colin.i.king@gmail.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: Replace /proc/fs/nfsd/supported_krb5_enctypes with a symlink

Now that I've added a file under /proc/net/rpc that is managed by
the SunRPC's Kerberos mechanism, replace NFSD's
supported_krb5_en

NFSD: Replace /proc/fs/nfsd/supported_krb5_enctypes with a symlink

Now that I've added a file under /proc/net/rpc that is managed by
the SunRPC's Kerberos mechanism, replace NFSD's
supported_krb5_enctypes file with a symlink to the new SunRPC proc
file, which contains exactly the same content.

Remarkably, commit b0b0c0a26e84 ("nfsd: add proc file listing
kernel's gss_krb5 enctypes") added the nfsd_supported_krb5_enctypes
file in 2011, but this file has never been documented in nfsd(7).

Tested-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: move reply cache initialization into nfsd startup

There's no need to start the reply cache before nfsd is up and running,
and doing so means that we register a shrinker for every net namespace

nfsd: move reply cache initialization into nfsd startup

There's no need to start the reply cache before nfsd is up and running,
and doing so means that we register a shrinker for every net namespace
instead of just the ones where nfsd is running.

Move it to the per-net nfsd startup instead.

Reported-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: register/unregister of nfsd-client shrinker at nfsd startup/shutdown time

Currently the nfsd-client shrinker is registered and unregistered at
the time the nfsd module is loaded and unloaded.

NFSD: register/unregister of nfsd-client shrinker at nfsd startup/shutdown time

Currently the nfsd-client shrinker is registered and unregistered at
the time the nfsd module is loaded and unloaded. The problem with this
is the shrinker is being registered before all of the relevant fields
in nfsd_net are initialized when nfsd is started. This can lead to an
oops when memory is low and the shrinker is called while nfsd is not
running.

This patch moves the register/unregister of nfsd-client shrinker from
module load/unload time to nfsd startup/shutdown time.

Fixes: 44df6f439a17 ("NFSD: add delegation reaper to react to low memory condition")
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: allow disabling NFSv2 at compile time

rpc.nfsd stopped supporting NFSv2 a year ago. Take the next logical
step toward deprecating it and allow NFSv2 support to be compiled out.

Add a new CONF

nfsd: allow disabling NFSv2 at compile time

rpc.nfsd stopped supporting NFSv2 a year ago. Take the next logical
step toward deprecating it and allow NFSv2 support to be compiled out.

Add a new CONFIG_NFSD_V2 option that can be turned off and rework the
CONFIG_NFSD_V?_ACL option dependencies. Add a description that
discourages enabling it.

Also, change the description of CONFIG_NFSD to state that the always-on
version is now 3 instead of 2.

Finally, add an #ifdef around "case 2:" in __write_versions. When NFSv2
is disabled at compile time, this should make the kernel ignore attempts
to disable it at runtime, but still error out when trying to enable it.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: ignore requests to disable unsupported versions

The kernel currently errors out if you attempt to enable or disable a
version that it doesn't recognize. Change it to ignore attempts to
disable

nfsd: ignore requests to disable unsupported versions

The kernel currently errors out if you attempt to enable or disable a
version that it doesn't recognize. Change it to ignore attempts to
disable an unrecognized version. If we don't support it, then there is
no harm in doing so.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: unregister shrinker when nfsd_init_net() fails

syzbot is reporting UAF read at register_shrinker_prepared() [1], for
commit 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on
lo

NFSD: unregister shrinker when nfsd_init_net() fails

syzbot is reporting UAF read at register_shrinker_prepared() [1], for
commit 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on
low memory condition") missed that nfsd4_leases_net_shutdown() from
nfsd_exit_net() is called only when nfsd_init_net() succeeded.
If nfsd_init_net() fails due to nfsd_reply_cache_init() failure,
register_shrinker() from nfsd4_init_leases_net() has to be undone
before nfsd_init_net() returns.

Link: https://syzkaller.appspot.com/bug?extid=ff796f04613b4c84ad89 [1]
Reported-by: syzbot <syzbot+ff796f04613b4c84ad89@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 7746b32f467b3813 ("NFSD: add shrinker to reap courtesy clients on low memory condition")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: use DEFINE_SHOW_ATTRIBUTE to define nfsd_file_cache_stats_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-b

nfsd: use DEFINE_SHOW_ATTRIBUTE to define nfsd_file_cache_stats_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: use DEFINE_SHOW_ATTRIBUTE to define nfsd_reply_cache_stats_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

nfsd_net is converted from seq_file->file instead of seq_file->pri

nfsd: use DEFINE_SHOW_ATTRIBUTE to define nfsd_reply_cache_stats_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

nfsd_net is converted from seq_file->file instead of seq_file->private in
nfsd_reply_cache_stats_show().

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
[ cel: reduce line length ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: use DEFINE_SHOW_ATTRIBUTE to define export_features_fops and supported_enctypes_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

Signed-off-by: ChenXiaoSong <chenxiaosong2@hu

nfsd: use DEFINE_SHOW_ATTRIBUTE to define export_features_fops and supported_enctypes_fops

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
[ cel: reduce line length ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: add shrinker to reap courtesy clients on low memory condition

Add courtesy_client_reaper to react to low memory condition triggered
by the system memory shrinker.

The delayed_work for the cou

NFSD: add shrinker to reap courtesy clients on low memory condition

Add courtesy_client_reaper to react to low memory condition triggered
by the system memory shrinker.

The delayed_work for the courtesy_client_reaper is scheduled on
the shrinker's count callback using the laundry_wq.

The shrinker's scan callback is not used for expiring the courtesy
clients due to potential deadlocks.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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nfsd: silence extraneous printk on nfsd.ko insertion

This printk pops every time nfsd.ko gets plugged in. Most kmods don't do
that and this one is not very informative. Olaf's email address seems to

nfsd: silence extraneous printk on nfsd.ko insertion

This printk pops every time nfsd.ko gets plugged in. Most kmods don't do
that and this one is not very informative. Olaf's email address seems to
be defunct at this point anyway. Just drop it.

Cc: Olaf Kirch <okir@suse.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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NFSD: refactoring v4 specific code to a helper in nfs4state.c

This patch moves the v4 specific code from nfsd_init_net() to
nfsd4_init_leases_net() helper in nfs4state.c

Signed-off-by: Dai Ngo <dai

NFSD: refactoring v4 specific code to a helper in nfs4state.c

This patch moves the v4 specific code from nfsd_init_net() to
nfsd4_init_leases_net() helper in nfs4state.c

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

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