Commit Graph

3965 Commits

Author SHA1 Message Date
Linus Torvalds
f2f80ac809 nfsd-6.9 fixes:
- Address a slow memory leak with RPC-over-TCP
 - Prevent another NFS4ERR_DELAY loop during CREATE_SESSION
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Merge tag 'nfsd-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Address a slow memory leak with RPC-over-TCP

 - Prevent another NFS4ERR_DELAY loop during CREATE_SESSION

* tag 'nfsd-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  nfsd: hold a lighter-weight client reference over CB_RECALL_ANY
  SUNRPC: Fix a slow server-side memory leak with RPC-over-TCP
2024-04-06 09:37:50 -07:00
Jeff Layton
10396f4df8 nfsd: hold a lighter-weight client reference over CB_RECALL_ANY
Currently the CB_RECALL_ANY job takes a cl_rpc_users reference to the
client. While a callback job is technically an RPC that counter is
really more for client-driven RPCs, and this has the effect of
preventing the client from being unhashed until the callback completes.

If nfsd decides to send a CB_RECALL_ANY just as the client reboots, we
can end up in a situation where the callback can't complete on the (now
dead) callback channel, but the new client can't connect because the old
client can't be unhashed. This usually manifests as a NFS4ERR_DELAY
return on the CREATE_SESSION operation.

The job is only holding a reference to the client so it can clear a flag
after the RPC completes. Fix this by having CB_RECALL_ANY instead hold a
reference to the cl_nfsdfs.cl_ref. Typically we only take that sort of
reference when dealing with the nfsdfs info files, but it should work
appropriately here to ensure that the nfs4_client doesn't disappear.

Fixes: 44df6f439a ("NFSD: add delegation reaper to react to low memory condition")
Reported-by: Vladimir Benes <vbenes@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-05 14:05:35 -04:00
Linus Torvalds
d8e8fbec00 nfsd-6.9 fixes:
- Address three recently introduced regressions
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Merge tag 'nfsd-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd fixes from Chuck Lever:

 - Address three recently introduced regressions

* tag 'nfsd-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: CREATE_SESSION must never cache NFS4ERR_DELAY replies
  SUNRPC: Revert 561141dd49
  nfsd: Fix error cleanup path in nfsd_rename()
2024-03-28 14:35:32 -07:00
Chuck Lever
99dc2ef039 NFSD: CREATE_SESSION must never cache NFS4ERR_DELAY replies
There are one or two cases where CREATE_SESSION returns
NFS4ERR_DELAY in order to force the client to wait a bit and try
CREATE_SESSION again. However, after commit e4469c6cc6 ("NFSD: Fix
the NFSv4.1 CREATE_SESSION operation"), NFSD caches that response in
the CREATE_SESSION slot. Thus, when the client resends the
CREATE_SESSION, the server always returns the cached NFS4ERR_DELAY
response rather than actually executing the request and properly
recording its outcome. This blocks the client from making further
progress.

RFC 8881 Section 15.1.1.3 says:
> If NFS4ERR_DELAY is returned on an operation other than SEQUENCE
> that validly appears as the first operation of a request ... [t]he
> request can be retried in full without modification. In this case
> as well, the replier MUST avoid returning a response containing
> NFS4ERR_DELAY as the response to an initial operation of a request
> solely on the basis of its presence in the reply cache.

Neither the original NFSD code nor the discussion in section 18.36.4
refer explicitly to this important requirement, so I missed it.

Note also that not only must the server not cache NFS4ERR_DELAY, but
it has to not advance the CREATE_SESSION slot sequence number so
that it can properly recognize and accept the client's retry.

Reported-by: Dai Ngo <dai.ngo@oracle.com>
Fixes: e4469c6cc6 ("NFSD: Fix the NFSv4.1 CREATE_SESSION operation")
Tested-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-27 13:19:47 -04:00
Jan Kara
9fe6e9e7b5 nfsd: Fix error cleanup path in nfsd_rename()
Commit a8b0026847 ("rename(): avoid a deadlock in the case of parents
having no common ancestor") added an error bail out path. However this
path does not drop the remount protection that has been acquired. Fix
the cleanup path to properly drop the remount protection.

Fixes: a8b0026847 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-22 09:52:00 -04:00
Steven Rostedt (Google)
c759e60903 tracing: Remove __assign_str_len()
Now that __assign_str() gets the length from the __string() (and
__string_len()) macros, there's no reason to have a separate
__assign_str_len() macro as __assign_str() can get the length of the
string needed.

Also remove __assign_rel_str() although it had no users anyway.

Link: https://lore.kernel.org/linux-trace-kernel/20240223152206.0b650659@gandalf.local.home

Cc: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:33:05 -04:00
Steven Rostedt (Google)
9388a2aa45 NFSD: Fix nfsd_clid_class use of __string_len() macro
I'm working on restructuring the __string* macros so that it doesn't need
to recalculate the string twice. That is, it will save it off when
processing __string() and the __assign_str() will not need to do the work
again as it currently does.

Currently __string_len(item, src, len) doesn't actually use "src", but my
changes will require src to be correct as that is where the __assign_str()
will get its value from.

The event class nfsd_clid_class has:

  __string_len(name, name, clp->cl_name.len)

But the second "name" does not exist and causes my changes to fail to
build. That second parameter should be: clp->cl_name.data.

Link: https://lore.kernel.org/linux-trace-kernel/20240222122828.3d8d213c@gandalf.local.home

Cc: Neil Brown <neilb@suse.de>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: stable@vger.kernel.org
Fixes: d27b74a867 ("NFSD: Use new __string_len C macros for nfsd_clid_class")
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-03-18 10:17:41 -04:00
Linus Torvalds
cc4a875cf3 lsm/stable-6.9 PR 20240312
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Merge tag 'lsm-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull lsm updates from Paul Moore:

 - Promote IMA/EVM to a proper LSM

   This is the bulk of the diffstat, and the source of all the changes
   in the VFS code. Prior to the start of the LSM stacking work it was
   important that IMA/EVM were separate from the rest of the LSMs,
   complete with their own hooks, infrastructure, etc. as it was the
   only way to enable IMA/EVM at the same time as a LSM.

   However, now that the bulk of the LSM infrastructure supports
   multiple simultaneous LSMs, we can simplify things greatly by
   bringing IMA/EVM into the LSM infrastructure as proper LSMs. This is
   something I've wanted to see happen for quite some time and Roberto
   was kind enough to put in the work to make it happen.

 - Use the LSM hook default values to simplify the call_int_hook() macro

   Previously the call_int_hook() macro required callers to supply a
   default return value, despite a default value being specified when
   the LSM hook was defined.

   This simplifies the macro by using the defined default return value
   which makes life easier for callers and should also reduce the number
   of return value bugs in the future (we've had a few pop up recently,
   hence this work).

 - Use the KMEM_CACHE() macro instead of kmem_cache_create()

   The guidance appears to be to use the KMEM_CACHE() macro when
   possible and there is no reason why we can't use the macro, so let's
   use it.

 - Fix a number of comment typos in the LSM hook comment blocks

   Not much to say here, we fixed some questionable grammar decisions in
   the LSM hook comment blocks.

* tag 'lsm-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (28 commits)
  cred: Use KMEM_CACHE() instead of kmem_cache_create()
  lsm: use default hook return value in call_int_hook()
  lsm: fix typos in security/security.c comment headers
  integrity: Remove LSM
  ima: Make it independent from 'integrity' LSM
  evm: Make it independent from 'integrity' LSM
  evm: Move to LSM infrastructure
  ima: Move IMA-Appraisal to LSM infrastructure
  ima: Move to LSM infrastructure
  integrity: Move integrity_kernel_module_request() to IMA
  security: Introduce key_post_create_or_update hook
  security: Introduce inode_post_remove_acl hook
  security: Introduce inode_post_set_acl hook
  security: Introduce inode_post_create_tmpfile hook
  security: Introduce path_post_mknod hook
  security: Introduce file_release hook
  security: Introduce file_post_open hook
  security: Introduce inode_post_removexattr hook
  security: Introduce inode_post_setattr hook
  security: Align inode_setattr hook definition with EVM
  ...
2024-03-12 20:03:34 -07:00
Linus Torvalds
a01c9fe323 NFSD 6.9 Release Notes
The bulk of the patches for this release are optimizations, code
 clean-ups, and minor bug fixes.
 
 One new feature to mention is that NFSD administrators now have the
 ability to revoke NFSv4 open and lock state. NFSD's NFSv3 support
 has had this capability for some time.
 
 As always I am grateful to NFSD contributors, reviewers, and
 testers.
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Merge tag 'nfsd-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull nfsd updates from Chuck Lever:
 "The bulk of the patches for this release are optimizations, code
  clean-ups, and minor bug fixes.

  One new feature to mention is that NFSD administrators now have the
  ability to revoke NFSv4 open and lock state. NFSD's NFSv3 support has
  had this capability for some time.

  As always I am grateful to NFSD contributors, reviewers, and testers"

* tag 'nfsd-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (75 commits)
  NFSD: Clean up nfsd4_encode_replay()
  NFSD: send OP_CB_RECALL_ANY to clients when number of delegations reaches its limit
  NFSD: Document nfsd_setattr() fill-attributes behavior
  nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr()
  nfsd: Fix a regression in nfsd_setattr()
  NFSD: OP_CB_RECALL_ANY should recall both read and write delegations
  NFSD: handle GETATTR conflict with write delegation
  NFSD: add support for CB_GETATTR callback
  NFSD: Document the phases of CREATE_SESSION
  NFSD: Fix the NFSv4.1 CREATE_SESSION operation
  nfsd: clean up comments over nfs4_client definition
  svcrdma: Add Write chunk WRs to the RPC's Send WR chain
  svcrdma: Post WRs for Write chunks in svc_rdma_sendto()
  svcrdma: Post the Reply chunk and Send WR together
  svcrdma: Move write_info for Reply chunks into struct svc_rdma_send_ctxt
  svcrdma: Post Send WR chain
  svcrdma: Fix retry loop in svc_rdma_send()
  svcrdma: Prevent a UAF in svc_rdma_send()
  svcrdma: Fix SQ wake-ups
  svcrdma: Increase the per-transport rw_ctx count
  ...
2024-03-12 14:27:37 -07:00
Linus Torvalds
0c750012e8 vfs-6.9.file
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Merge tag 'vfs-6.9.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull file locking updates from Christian Brauner:
 "A few years ago struct file_lock_context was added to allow for
  separate lists to track different types of file locks instead of using
  a singly-linked list for all of them.

  Now leases no longer need to be tracked using struct file_lock.
  However, a lot of the infrastructure is identical for leases and locks
  so separating them isn't trivial.

  This splits a group of fields used by both file locks and leases into
  a new struct file_lock_core. The new core struct is embedded in struct
  file_lock. Coccinelle was used to convert a lot of the callers to deal
  with the move, with the remaining 25% or so converted by hand.

  Afterwards several internal functions in fs/locks.c are made to work
  with struct file_lock_core. Ultimately this allows to split struct
  file_lock into struct file_lock and struct file_lease. The file lease
  APIs are then converted to take struct file_lease"

* tag 'vfs-6.9.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (51 commits)
  filelock: fix deadlock detection in POSIX locking
  filelock: always define for_each_file_lock()
  smb: remove redundant check
  filelock: don't do security checks on nfsd setlease calls
  filelock: split leases out of struct file_lock
  filelock: remove temporary compatibility macros
  smb/server: adapt to breakup of struct file_lock
  smb/client: adapt to breakup of struct file_lock
  ocfs2: adapt to breakup of struct file_lock
  nfsd: adapt to breakup of struct file_lock
  nfs: adapt to breakup of struct file_lock
  lockd: adapt to breakup of struct file_lock
  fuse: adapt to breakup of struct file_lock
  gfs2: adapt to breakup of struct file_lock
  dlm: adapt to breakup of struct file_lock
  ceph: adapt to breakup of struct file_lock
  afs: adapt to breakup of struct file_lock
  9p: adapt to breakup of struct file_lock
  filelock: convert seqfile handling to use file_lock_core
  filelock: convert locks_translate_pid to take file_lock_core
  ...
2024-03-11 10:37:45 -07:00
Chuck Lever
9b350d3e34 NFSD: Clean up nfsd4_encode_replay()
Replace open-coded encoding logic with the use of conventional XDR
utility functions. Add a tracepoint to make replays observable in
field troubleshooting situations.

The WARN_ON is removed. A stack trace is of little use, as there is
only one call site for nfsd4_encode_replay(), and a buffer length
shortage here is unlikely.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-09 13:57:50 -05:00
Dai Ngo
bad4c585cc NFSD: send OP_CB_RECALL_ANY to clients when number of delegations reaches its limit
The NFS server should ask clients to voluntarily return unused
delegations when the number of granted delegations reaches the
max_delegations. This is so that the server can continue to
grant delegations for new requests.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-05 10:22:33 -05:00
Chuck Lever
7d5a352ccc NFSD: Document nfsd_setattr() fill-attributes behavior
Add an explanation to prevent the future removal of the fill-
attribute call sites in nfsd_setattr(). Some NFSv3 client
implementations don't behave correctly if wcc data is not present in
an NFSv3 SETATTR reply.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-05 10:22:33 -05:00
Trond Myklebust
24d92de918 nfsd: Fix NFSv3 atomicity bugs in nfsd_setattr()
The main point of the guarded SETATTR is to prevent races with other
WRITE and SETATTR calls. That requires that the check of the guard time
against the inode ctime be done after taking the inode lock.

Furthermore, we need to take into account the 32-bit nature of
timestamps in NFSv3, and the possibility that files may change at a
faster rate than once a second.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:33 -05:00
Trond Myklebust
6412e44c40 nfsd: Fix a regression in nfsd_setattr()
Commit bb4d53d66e ("NFSD: use (un)lock_inode instead of
fh_(un)lock for file operations") broke the NFSv3 pre/post op
attributes behaviour when doing a SETATTR rpc call by stripping out
the calls to fh_fill_pre_attrs() and fh_fill_post_attrs().

Fixes: bb4d53d66e ("NFSD: use (un)lock_inode instead of fh_(un)lock for file operations")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neilb@suse.de>
Message-ID: <20240216012451.22725-1-trondmy@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:33 -05:00
Dai Ngo
5826e09bf3 NFSD: OP_CB_RECALL_ANY should recall both read and write delegations
Add RCA4_TYPE_MASK_WDATA_DLG to ra_bmval bitmask of OP_CB_RECALL_ANY

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:32 -05:00
Dai Ngo
c5967721e1 NFSD: handle GETATTR conflict with write delegation
If the GETATTR request on a file that has write delegation in effect
and the request attributes include the change info and size attribute
then the request is handled as below:

Server sends CB_GETATTR to client to get the latest change info and file
size. If these values are the same as the server's cached values then
the GETATTR proceeds as normal.

If either the change info or file size is different from the server's
cached values, or the file was already marked as modified, then:

    . update time_modify and time_metadata into file's metadata
      with current time

    . encode GETATTR as normal except the file size is encoded with
      the value returned from CB_GETATTR

    . mark the file as modified

If the CB_GETATTR fails for any reasons, the delegation is recalled
and NFS4ERR_DELAY is returned for the GETATTR.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:32 -05:00
Dai Ngo
6487a13b5c NFSD: add support for CB_GETATTR callback
Includes:
   . CB_GETATTR proc for nfs4_cb_procedures[]
   . XDR encoding and decoding function for CB_GETATTR request/reply
   . add nfs4_cb_fattr to nfs4_delegation for sending CB_GETATTR
     and store file attributes from client's reply.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:31 -05:00
Chuck Lever
b910544a5a NFSD: Document the phases of CREATE_SESSION
As described in RFC 8881 Section 18.36.4, CREATE_SESSION can be
split into four phases. NFSD's implementation now does it like that
description.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:31 -05:00
Chuck Lever
e4469c6cc6 NFSD: Fix the NFSv4.1 CREATE_SESSION operation
RFC 8881 Section 18.36.4 discusses the implementation of the NFSv4.1
CREATE_SESSION operation. The section defines four phases of
operation.

Phase 2 processes the CREATE_SESSION sequence ID. As a separate
step, Phase 3 evaluates the CREATE_SESSION arguments.

The problem we are concerned with is when phase 2 is successful but
phase 3 fails. The spec language in this case is "No changes are
made to any client records on the server."

RFC 8881 Section 18.35.4 defines a "client record", and it does
/not/ contain any details related to the special CREATE_SESSION
slot. Therefore NFSD is incorrect to skip incrementing the
CREATE_SESSION sequence id when phase 3 (see Section 18.36.4) of
CREATE_SESSION processing fails. In other words, even though NFSD
happens to store the cs_slot in a client record, in terms of the
protocol the slot is logically separate from the client record.

Three complications:

1. The world has moved on since commit 86c3e16cc7 ("nfsd4: confirm
   only on succesful create_session") broke this. So we can't simply
   revert that commit.

2. NFSD's CREATE_SESSION implementation does not cleanly delineate
   the logic of phases 2 and 3. So this won't be a surgical fix.

3. Because of the way it currently handles the CREATE_SESSION slot
   sequence number, nfsd4_create_session() isn't caching error
   responses in the CREATE_SESSION slot. Instead of replaying the
   response cache in those cases, it's executing the transaction
   again.

Reorganize the CREATE_SESSION slot sequence number accounting. This
requires that error responses are appropriately cached in the
CREATE_SESSION slot (once it is found).

Reported-by: Connor Smith <connor.smith@hitachivantara.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218382
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:31 -05:00
Chen Hanxiao
f81040276a nfsd: clean up comments over nfs4_client definition
nfsd fault injection has been deprecated since
commit 9d60d93198 ("Deprecate nfsd fault injection")
and removed by
commit e56dc9e294 ("nfsd: remove fault injection code")

So remove the outdated parts about fault injection.

Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:30 -05:00
Kunwu Chan
649e58d593 nfsd: Simplify the allocation of slab caches in nfsd4_init_slabs
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Make the code cleaner and more readable.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:24 -05:00
Kunwu Chan
192d80cdcb nfsd: Simplify the allocation of slab caches in nfsd_drc_slab_create
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
And change cache name from 'nfsd_drc' to 'nfsd_cacherep'.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:24 -05:00
Kunwu Chan
2f74991a49 nfsd: Simplify the allocation of slab caches in nfsd_file_cache_init
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:23 -05:00
Kunwu Chan
10bcc2f1c8 nfsd: Simplify the allocation of slab caches in nfsd4_init_pnfs
commit 0a31bd5f2b ("KMEM_CACHE(): simplify slab cache creation")
introduces a new macro.
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:23 -05:00
NeilBrown
05eda6e757 nfsd: don't call locks_release_private() twice concurrently
It is possible for free_blocked_lock() to be called twice concurrently,
once from nfsd4_lock() and once from nfsd4_release_lockowner() calling
remove_blocked_locks().  This is why a kref was added.

It is perfectly safe for locks_delete_block() and kref_put() to be
called in parallel as they use locking or atomicity respectively as
protection.  However locks_release_private() has no locking.  It is
safe for it to be called twice sequentially, but not concurrently.

This patch moves that call from free_blocked_lock() where it could race
with itself, to free_nbl() where it cannot.  This will slightly delay
the freeing of private info or release of the owner - but not by much.
It is arguably more natural for this freeing to happen in free_nbl()
where the structure itself is freed.

This bug was found by code inspection - it has not been seen in practice.

Fixes: 47446d74f1 ("nfsd4: add refcount for nfsd4_blocked_lock")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:23 -05:00
NeilBrown
1e33e1414b nfsd: allow layout state to be admin-revoked.
When there is layout state on a filesystem that is being "unlocked" that
is now revoked, which involves closing the nfsd_file and releasing the
vfs lease.

To avoid races, ->ls_file can now be accessed either:
 - under ->fi_lock for the state's sc_file or
 - under rcu_read_lock() if nfsd_file_get() is used.
To support this, ->fence_client and nfsd4_cb_layout_fail() now take a
second argument being the nfsd_file.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:22 -05:00
NeilBrown
06efa66750 nfsd: allow delegation state ids to be revoked and then freed
Revoking state through 'unlock_filesystem' now revokes any delegation
states found.  When the stateids are then freed by the client, the
revoked stateids will be cleaned up correctly.

As there is already support for revoking delegations, we build on that
for admin-revoking.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:22 -05:00
NeilBrown
39657c7406 nfsd: allow open state ids to be revoked and then freed
Revoking state through 'unlock_filesystem' now revokes any open states
found.  When the stateids are then freed by the client, the revoked
stateids will be cleaned up correctly.

Possibly the related lock states should be revoked too, but a
subsequent patch will do that for all lock state on the superblock.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:21 -05:00
NeilBrown
1c13bf9f2e nfsd: allow lock state ids to be revoked and then freed
Revoking state through 'unlock_filesystem' now revokes any lock states
found.  When the stateids are then freed by the client, the revoked
stateids will be cleaned up correctly.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:21 -05:00
NeilBrown
d688d8585e nfsd: allow admin-revoked NFSv4.0 state to be freed.
For NFSv4.1 and later the client easily discovers if there is any
admin-revoked state and will then find and explicitly free it.

For NFSv4.0 there is no such mechanism.  The client can only find that
state is admin-revoked if it tries to use that state, and there is no
way for it to explicitly free the state.  So the server must hold on to
the stateid (at least) for an indefinite amount of time.  A
RELEASE_LOCKOWNER request might justify forgetting some of these
stateids, as would the whole clients lease lapsing, but these are not
reliable.

This patch takes two approaches.

Whenever a client uses an revoked stateid, that stateid is then
discarded and will not be recognised again.  This might confuse a client
which expect to get NFS4ERR_ADMIN_REVOKED consistently once it get it at
all, but should mostly work.  Hopefully one error will lead to other
resources being closed (e.g.  process exits), which will result in more
stateid being freed when a CLOSE attempt gets NFS4ERR_ADMIN_REVOKED.

Also, any admin-revoked stateids that have been that way for more than
one lease time are periodically revoke.

No actual freeing of state happens in this patch.  That will come in
future patches which handle the different sorts of revoked state.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:21 -05:00
NeilBrown
11b2cfbf6c nfsd: report in /proc/fs/nfsd/clients/*/states when state is admin-revoke
Add "admin-revoked" to the status information for any states that have
been admin-revoked.  This can be useful for confirming correct
behaviour.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:20 -05:00
NeilBrown
39e1be6471 nfsd: allow state with no file to appear in /proc/fs/nfsd/clients/*/states
Change the "show" functions to show some content even if a file cannot
be found.  This is the case for admin-revoked state.
This is primarily useful for debugging - to ensure states are being
removed eventually.

So change several seq_printf() to seq_puts().  Some of these are needed
to keep checkpatch happy.  Others were done for consistency.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:20 -05:00
NeilBrown
1ac3629bf0 nfsd: prepare for supporting admin-revocation of state
The NFSv4 protocol allows state to be revoked by the admin and has error
codes which allow this to be communicated to the client.

This patch
 - introduces a new state-id status SC_STATUS_ADMIN_REVOKED
   which can be set on open, lock, or delegation state.
 - reports NFS4ERR_ADMIN_REVOKED when these are accessed
 - introduces a per-client counter of these states and returns
   SEQ4_STATUS_ADMIN_STATE_REVOKED when the counter is not zero.
   Decrements this when freeing any admin-revoked state.
 - introduces stub code to find all interesting states for a given
   superblock so they can be revoked via the 'unlock_filesystem'
   file in /proc/fs/nfsd/
   No actual states are handled yet.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:19 -05:00
NeilBrown
3f29cc82a8 nfsd: split sc_status out of sc_type
sc_type identifies the type of a state - open, lock, deleg, layout - and
also the status of a state - closed or revoked.

This is a bit untidy and could get worse when "admin-revoked" states are
added.  So clean it up.

With this patch, the type is now all that is stored in sc_type.  This is
zero when the state is first added to ->cl_stateids (causing it to be
ignored), and is then set appropriately once it is fully initialised.
It is set under ->cl_lock to ensure atomicity w.r.t lookup.  It is now
never cleared.

sc_type is still a bit-set even though at most one bit is set.  This allows
lookup functions to be given a bitmap of acceptable types.

sc_type is now an unsigned short rather than char.  There is no value in
restricting to just 8 bits.

All the constants now start SC_TYPE_ matching the field in which they
are stored.  Keeping the existing names and ensuring clear separation
from non-type flags would have required something like
NFS4_STID_TYPE_CLOSED which is cumbersome.  The "NFS4" prefix is
redundant was they only appear in NFS4 code, so remove that and change
STID to SC to match the field.

The status is stored in a separate unsigned short named "sc_status".  It
has two flags: SC_STATUS_CLOSED and SC_STATUS_REVOKED.
CLOSED combines NFS4_CLOSED_STID, NFS4_CLOSED_DELEG_STID, and is used
for SC_TYPE_LOCK and SC_TYPE_LAYOUT instead of setting the sc_type to zero.
These flags are only ever set, never cleared.
For deleg stateids they are set under the global state_lock.
For open and lock stateids they are set under ->cl_lock.
For layout stateids they are set under ->ls_lock

nfs4_unhash_stid() has been removed, and we never set sc_type = 0.  This
was only used for LOCK and LAYOUT stids and they now use
SC_STATUS_CLOSED.

Also TRACE_DEFINE_NUM() calls for the various STID #define have been
removed because these things are not enums, and so that call is
incorrect.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:19 -05:00
NeilBrown
83e733161f nfsd: avoid race after unhash_delegation_locked()
NFS4_CLOSED_DELEG_STID and NFS4_REVOKED_DELEG_STID are similar in
purpose.
REVOKED is used for NFSv4.1 states which have been revoked because the
lease has expired.  CLOSED is used in other cases.
The difference has two practical effects.
1/ REVOKED states are on the ->cl_revoked list
2/ REVOKED states result in nfserr_deleg_revoked from
   nfsd4_verify_open_stid() and nfsd4_validate_stateid while
   CLOSED states result in nfserr_bad_stid.

Currently a state that is being revoked is first set to "CLOSED" in
unhash_delegation_locked(), then possibly to "REVOKED" in
revoke_delegation(), at which point it is added to the cl_revoked list.

It is possible that a stateid test could see the CLOSED state
which really should be REVOKED, and so return the wrong error code.  So
it is safest to remove this window of inconsistency.

With this patch, unhash_delegation_locked() always sets the state
correctly, and revoke_delegation() no longer changes the state.

Also remove a redundant test on minorversion when
NFS4_REVOKED_DELEG_STID is seen - it can only be seen when minorversion
is non-zero.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:19 -05:00
NeilBrown
c6540026df nfsd: don't call functions with side-effecting inside WARN_ON()
Code like:

    WARN_ON(foo())

looks like an assertion and might not be expected to have any side
effects.
When testing if a function with side-effects fails a construct like

    if (foo())
       WARN_ON(1);

makes the intent more obvious.

nfsd has several WARN_ON calls where the test has side effects, so it
would be good to change them.  These cases don't really need the
WARN_ON.  They have never failed in 8 years of usage so let's just
remove the WARN_ON wrapper.

Suggested-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:18 -05:00
NeilBrown
779457285a nfsd: hold ->cl_lock for hash_delegation_locked()
The protocol for creating a new state in nfsd is to allocate the state
leaving it largely uninitialised, add that state to the ->cl_stateids
idr so as to reserve a state-id, then complete initialisation of the
state and only set ->sc_type to non-zero once the state is fully
initialised.

If a state is found in the idr with ->sc_type == 0, it is ignored.
The ->cl_lock lock is used to avoid races - it is held while checking
sc_type during lookup, and held when a non-zero value is stored in
->sc_type.

... except... hash_delegation_locked() finalises the initialisation of a
delegation state, but does NOT hold ->cl_lock.

So this patch takes ->cl_lock at the appropriate time w.r.t other locks,
and so ensures there are no races (which are extremely unlikely in any
case).
As ->fi_lock is often taken when ->cl_lock is held, we need to take
->cl_lock first of those two.
Currently ->cl_lock and state_lock are never both taken at the same time.
We need both for this patch so an arbitrary choice is needed concerning
which to take first.  As state_lock is more global, it might be more
contended, so take it first.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:18 -05:00
NeilBrown
6b4ca49dc3 nfsd: remove stale comment in nfs4_show_deleg()
As we do now support write delegations, this comment is unhelpful and
misleading.

Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:17 -05:00
Chuck Lever
e3179e443c NFSD: Remove redundant cb_seq_status initialization
As far as I can see, setting cb_seq_status in nfsd4_init_cb() is
superfluous because it is set again in nfsd4_cb_prepare().

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:17 -05:00
Chuck Lever
84ebf02d75 NFSD: Remove BUG_ON in nfsd4_process_cb_update()
Don't kill the kworker thread, and don't panic while cl_lock is
held. There's no need for scorching the earth here.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:16 -05:00
Chuck Lever
112bdd597d NFSD: Replace comment with lockdep assertion
Convert a code comment into a real assertion.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:16 -05:00
Chuck Lever
627fb18302 NFSD: Remove unused @reason argument
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:15 -05:00
Chuck Lever
9a026aec88 NFSD: Add callback operation lifetime trace points
Help observe the flow of callback operations.

bc_shutdown() records exactly when the backchannel RPC client is
destroyed and cl_cb_client is replaced with NULL.

Examples include:

         nfsd-955   [004]   650.013997: nfsd_cb_queue:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u21:4-497   [004]   650.014050: nfsd_cb_seq_status:   task:00000001@00000001 sessionid=65b3c5b8:f541f749:00000001:00000000 tk_status=-107 seq_status=1
kworker/u21:4-497   [004]   650.014051: nfsd_cb_restart:      addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (first try)
kworker/u21:4-497   [004]   650.014066: nfsd_cb_queue:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff88810e39f400 (need restart)


kworker/u16:0-10    [006]   650.065750: nfsd_cb_start:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN
kworker/u16:0-10    [006]   650.065752: nfsd_cb_bc_update:    addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u16:0-10    [006]   650.065754: nfsd_cb_bc_shutdown:  addr=192.168.122.6:0 client 65b3c5b8:f541f749 cb=0xffff8881134b02f8 (first try)
kworker/u16:0-10    [006]   650.065810: nfsd_cb_new_state:    addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:15 -05:00
Chuck Lever
a7cdf065e1 NFSD: Rename nfsd_cb_state trace point
Make it clear where backchannel state is updated.

Example trace point output:

kworker/u16:0-10    [006]  2800.080404: nfsd_cb_new_state:    addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UP
         nfsd-940   [003]  2800.478368: nfsd_cb_new_state:    addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN
kworker/u16:0-10    [003]  2800.478828: nfsd_cb_new_state:    addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN

kworker/u16:0-10    [005]  2802.039724: nfsd_cb_start:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UP
kworker/u16:0-10    [005]  2810.611452: nfsd_cb_start:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=FAULT
kworker/u16:0-10    [005]  2810.616832: nfsd_cb_start:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=UNKNOWN
kworker/u16:0-10    [005]  2810.616931: nfsd_cb_start:        addr=192.168.122.6:0 client 65b3c5b8:f541f749 state=DOWN

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:14 -05:00
Chuck Lever
8626664c87 NFSD: Replace dprintks in nfsd4_cb_sequence_done()
Improve observability of backchannel session operation.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:14 -05:00
Chuck Lever
f52f1975b1 NFSD: Add nfsd_seq4_status trace event
Add a trace point that records SEQ4_STATUS flags returned in an
NFSv4.1 SEQUENCE response. SEQ4_STATUS flags report backchannel
issues and changes to lease state to clients. Knowing what the
server is reporting to clients is useful for debugging both
configuration and operational issues in real time.

For example, upcoming patches will enable server administrators to
revoke parts of a client's lease; that revocation is indicated to
the client when a subsequent SEQUENCE operation has one or more
SEQ4_STATUS flags that are set.

Sample trace records:

nfsd-927   [006]   615.581821: nfsd_seq4_status:     xid=0x095ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT
nfsd-927   [006]   615.588043: nfsd_seq4_status:     xid=0x0a5ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT
nfsd-928   [003]   615.588448: nfsd_seq4_status:     xid=0x0b5ded07 sessionid=65a032c3:b7845faf:00000001:00000000 status_flags=BACKCHANNEL_FAULT

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:13 -05:00
Chuck Lever
43b02dba11 NFSD: Retransmit callbacks after client reconnects
NFSv4.1 clients assume that if they disconnect, that will force the
server to resend pending callback operations once a fresh connection
has been established.

Turns out NFSD has not been resending after reconnect.

Fixes: 7ba6cad6c8 ("nfsd: New helper nfsd4_cb_sequence_done() for processing more cb errors")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:13 -05:00
Chuck Lever
c1ccfcf1a9 NFSD: Reschedule CB operations when backchannel rpc_clnt is shut down
As part of managing a client disconnect, NFSD closes down and
replaces the backchannel rpc_clnt.

If a callback operation is pending when the backchannel rpc_clnt is
shut down, currently nfsd4_run_cb_work() just discards that
callback. But there are multiple cases to deal with here:

 o The client's lease is getting destroyed. Throw the CB away.

 o The client disconnected. It might be forcing a retransmit of
   CB operations, or it could have disconnected for other reasons.
   Reschedule the CB so it is retransmitted when the client
   reconnects.

Since callback operations can now be rescheduled, ensure that
cb_ops->prepare can be called only once by moving the
cb_ops->prepare paragraph down to just before the rpc_call_async()
call.

Fixes: 2bbfed98a4 ("nfsd: Fix races between nfsd4_cb_release() and nfsd4_shutdown_callback()")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:12 -05:00
Chuck Lever
fe0e9580e2 NFSD: Convert the callback workqueue to use delayed_work
Normally, NFSv4 callback operations are supposed to be sent to the
client as soon as they are queued up.

In a moment, I will introduce a recovery path where the server has
to wait for the client to reconnect. We don't want a hard busy wait
here -- the callback should be requeued to try again in several
milliseconds.

For now, convert nfsd4_callback from struct work_struct to struct
delayed_work, and queue with a zero delay argument. This should
avoid behavior changes for current operation.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-03-01 09:12:12 -05:00