Jan Schunk reports that his small NFS servers suffer from memory
exhaustion after just a few days. A bisect shows that commit
e18e157bb5 ("SUNRPC: Send RPC message on TCP with a single
sock_sendmsg() call") is the first bad commit.
That commit assumed that sock_sendmsg() releases all the pages in
the underlying bio_vec array, but the reality is that it doesn't.
svc_xprt_release() releases the rqst's response pages, but the
record marker page fragment isn't one of those, so it is never
released.
This is a narrow fix that can be applied to stable kernels. A
more extensive fix is in the works.
Reported-by: Jan Schunk <scpcom@gmx.de>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218671
Fixes: e18e157bb5 ("SUNRPC: Send RPC message on TCP with a single sock_sendmsg() call")
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
Scott reports an occasional scatterlist BUG that is triggered by the
RFC 8009 Kunit test, then says:
> Looking through the git history of the auth_gss code, there are various
> places where static buffers were replaced by dynamically allocated ones
> because they're being used with scatterlists.
Reported-by: Scott Mayhew <smayhew@redhat.com>
Fixes: 561141dd49 ("SUNRPC: Use a static buffer for the checksum initialization vector")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Chain RDMA Writes that convey Write chunks onto the local Send
chain. This means all WRs for an RPC Reply are now posted with a
single ib_post_send() call, and there is a single Send completion
when all of these are done. That reduces both the per-transport
doorbell rate and completion rate.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor to eventually enable svcrdma to post the Write WRs for each
RPC response using the same ib_post_send() as the Send WR (ie, as a
single WR chain).
svc_rdma_result_payload (originally svc_rdma_read_payload) was added
so that the upper layer XDR encoder could identify a range of bytes
to be possibly conveyed by RDMA (if a Write chunk was provided by
the client).
The purpose of commit f6ad77590a ("svcrdma: Post RDMA Writes while
XDR encoding replies") was to post as much of the result payload
outside of svc_rdma_sendto() as possible because svc_rdma_sendto()
used to be called with the xpt_mutex held.
However, since commit ca4faf543a ("SUNRPC: Move xpt_mutex into
socket xpo_sendto methods"), the xpt_mutex is no longer held when
calling svc_rdma_sendto(). Thus, that benefit is no longer an issue.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reduce the doorbell and Send completion rates when sending RPC/RDMA
replies that have Reply chunks. NFS READDIR procedures typically
return their result in a Reply chunk, for example.
Instead of calling ib_post_send() to post the Write WRs for the
Reply chunk, and then calling it again to post the Send WR that
conveys the transport header, chain the Write WRs to the Send WR
and call ib_post_send() only once.
Thanks to the Send Queue completion ordering rules, when the Send
WR completes, that guarantees that Write WRs posted before it have
also completed successfully. Thus all Write WRs for the Reply chunk
can remain unsignaled. Instead of handling a Write completion and
then a Send completion, only the Send completion is seen, and it
handles clean up for both the Writes and the Send.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Since the RPC transaction's svc_rdma_send_ctxt will stay around for
the duration of the RDMA Write operation, the write_info structure
for the Reply chunk can reside in the request's svc_rdma_send_ctxt
instead of being allocated separately.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Eventually I'd like the server to post the reply's Send WR along
with any Write WRs using only a single call to ib_post_send(), in
order to reduce the NIC's doorbell rate.
To do this, add an anchor for a WR chain to svc_rdma_send_ctxt, and
refactor svc_rdma_send() to post this WR chain to the Send Queue. For
the moment, the posted chain will continue to contain a single Send
WR.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
In some error flow cases, svc_rdma_wc_send() releases @ctxt. Copy
the sc_cid field in @ctxt to a stack variable in order to guarantee
that the value is available after the ib_post_send() call.
In case the new comment looks a little strange, this will be done
with at least one more field in a subsequent patch.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Ensure there is a wake-up when increasing sc_sq_avail.
Likewise, if a wake-up is done, sc_sq_avail needs to be updated,
otherwise the wait_event() conditional is never going to be met.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
rdma_rw_mr_factor() returns the smallest number of MRs needed to
move a particular number of pages. svcrdma currently asks for the
number of MRs needed to move RPCSVC_MAXPAGES (a little over one
megabyte), as that is the number of pages in the largest r/wsize
the server supports.
This call assumes that the client's NIC can bundle a full one
megabyte payload in a single rdma_segment. In fact, most NICs cannot
handle a full megabyte with a single rkey / rdma_segment. Clients
will typically split even a single Read chunk into many segments.
The server needs one MR to read each rdma_segment in a Read chunk,
and thus each one needs an rw_ctx.
svcrdma has been vastly underestimating the number of rw_ctxs needed
to handle 64 RPC requests with large Read chunks using small
rdma_segments.
Unfortunately there doesn't seem to be a good way to estimate this
number without knowing the client NIC's capabilities. Even then,
the client RPC/RDMA implementation is still free to split a chunk
into smaller segments (for example, it might be using physical
registration, which needs an rdma_segment per page).
The best we can do for now is choose a number that will guarantee
forward progress in the worst case (one page per segment).
At some later point, we could add some mechanisms to make this
much less of a problem:
- Add a core API to add more rw_ctxs to an already-established QP
- svcrdma could treat rw_ctx exhaustion as a temporary error and
try again
- Limit the number of Reads in flight
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
rdma_create_qp() can modify cap.max_send_sges. Copy the new value
to the svcrdma transport so it is bound by the new limit instead
of the requested one.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Do as other ULPs already do: ensure there is an extra Receive WQE
reserved for the tear-down drain WR. I haven't heard reports of
problems but it can't hurt.
Note that rq_depth is used to compute the Send Queue depth as well,
so this fix should affect both the SQ and RQ.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Alex helps co-maintain the DLM code and did some recent work to fix up
how lockd and GFS2 work together. Add him as a Reviewer for file locking
changes.
Acked-by: Alexander Aring <aahringo@redhat.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
bc_close() and bc_destroy now do something, so the comments are
no longer correct. Commit 6221f1d9b6 ("SUNRPC: Fix backchannel
RPC soft lockups") should have removed these.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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>
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>
