When an open or lock stateid is hashed, we take an extra reference to
it. When we unhash it, we drop that reference. The code however does
not properly account for the case where we have two callers concurrently
trying to unhash the stateid. This can lead to list corruption and the
hash reference being put more than once.

Fix this by having unhash_ol_stateid use list_del_init on the st_perfile
list_head, and then testing to see if that list_head is empty before
releasing the hash reference. This means that some of the unhashing
wrappers now become bool return functions so we can test to see whether
the stateid was unhashed before we put the reference.
Reported-by: NAndrew W Elble <aweits@rit.edu>
Tested-by: NAndrew W Elble <aweits@rit.edu>
Reported-by: NAnna Schumaker <Anna.Schumaker@netapp.com>
Tested-by: NAnna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

`perf stat  -e sunrpc:svc_xprt_do_enqueue true` results in

Warning: unknown op '->'
Warning: [sunrpc:svc_xprt_do_enqueue] unknown op '->'

Similar warning for svc_handle_xprt as well.

Actually TP_printk() should never dereference an address saved in the ring
buffer that points somewhere in the kernel. There's no guarantee that that
object still exists (with the exception of static strings).

Therefore change all the arguments for TP_printk(), so that it references
values existing in the ring buffer only.

While doing that, also fix another possible bug when argument xprt could be
NULL and TP_fast_assign() tries to access it's elements.
Signed-off-by: NPratyush Anand <panand@redhat.com>
Reviewed-by: NJeff Layton <jeff.layton@primarydata.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fixes: 83a712e0 "sunrpc: add some tracepoints around ..."
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We can potentially have several nfs4_laundromat jobs running if there
are multiple namespaces running nfsd on the box. Those are effectively
separated from one another though, so I don't see any reason to
serialize them.

Also, create_singlethread_workqueue automatically adds the
WQ_MEM_RECLAIM flag. Since we run this job on a timer, it's not really
involved in any reclaim paths. I see no need for a rescuer thread.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

These messages, combined with the backtrace they trigger, makes it seem
like a serious problem, though a quick search shows distros marking
it as a "won't fix" non-issue when the problem is reported by users.

The backtrace is overkill, and only really manages to show that if
you follow the code path, you can't really avoid it with bootargs
or configuration settings in the container.

Given that, lets tone it down a bit and get rid of the WARN severity,
and the associated backtrace, so people aren't needlessly alarmed.

Also, lets drop the split printk line, since they are grep unfriendly.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fix kernel-doc warnings in fs/locks.c:

Warning(..//fs/locks.c:1577): No description found for parameter 'flags'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>

Jeff has been doing a lot of development (including much of the
state-locking rewrite just as one example) plus lots of review and other
miscellaneous nfsd work, so let's acknowledge the status quo.

I'll continue to be the one to send regular pull requests but Jeff will
should be available to cover there occasionally too.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Security label can be set in OPEN/CREATE request, nfsd should set
the bitmask in word2 if setting success.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

According to rfc5661 18.16.4,
"If EXCLUSIVE4_1 was used, the client determines the attributes
 used for the verifier by comparing attrset with cva_attrs.attrmask;"

So, EXCLUSIVE4_1 also needs those bitmask used to store the verifier.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The encode order should be as the bitmask defined order.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently we'll respond correctly to a request for either
FS_LAYOUT_TYPES or LAYOUT_TYPES, but not to a request for both
attributes simultaneously.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

After commit ae7095a7 (nfsd4: helper function for getting mounted_on
ino) we ignore the return value from get_parent_attributes().

Also, the following FATTR4_WORD2_LAYOUT_BLKSIZE uses stat.blksize, so to
avoid overwriting that, use an independent value for the parent's
attributes.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

(espect -> expect) and (no -> know)
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

NLM locks don't conflict with NFSv4 share reservations, so we're not
going to learn anything new by watiting for them.

They do conflict with NFSv4 locks and with delegations.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

export.h refers to the pnfs_layouttype enum, which is defined there.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Switch using list_head for cache_head in cache_detail,
it is useful of remove an cache_head entry directly from cache_detail.

v8, using hash list, not head list
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Nfsd has implement a site of seq_operations functions as sunrpc's cache.
Just exports sunrpc's codes, and remove nfsd's redundant codes.

v8, same as v6
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Cleanup.

Just store cache_detail in seq_file's private,
an allocated handle is redundant.

v8, same as v6.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

According to Christoph's advice, this patch introduce a new helper
nfsd4_cb_sequence_done() for processing more callback errors, following
the example of the client's nfs41_sequence_done().
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Commit 294ac32e "nfsd: protect clid and verifier generation with
client_lock" moved gen_confirm() to gen_clid().

After that commit, setclientid will return a bad reply with all-zero
verifier after copy_clid().
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If using clientid_counter, it seems possible that gen_confirm could
generate the same verifier for the same client in some situations.

Add a new counter for client confirm verifier to make sure gen_confirm
generates a different verifier on each call for the same clientid.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

v2, new helper nfs4_free_stateowner for freeing so_owner.data and sop
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Layout is a state resource, nfsd should check it too.

v2, drop unneeded updating in nfsd4_renew()
v3, fix compile error without CONFIG_NFSD_PNFS
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In later patches, we'll want to be able to allocate and free svc_rqst
structures without monkeying with the serv->sv_nrthreads refcount.

Factor those pieces out of their respective functions.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In later patches, we're going to need to allow code external to svc.c
to figure out what pool_mode is in use. Move these definitions into
svc.h to prepare for that.

Also, make the svc_pool_map object available and exported so that other
modules can peek in there to get insight into what pool mode is in use.
Likewise, export svc_pool_map_get/put function to make it safe to do so.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add an operation that will do setup of the service. In the case of a
classic thread-based service that means starting up threads. In the case
of a workqueue-based service, the setup will do something different.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirliey.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For now, all services use svc_xprt_do_enqueue, but once we add
workqueue-based service support, we'll need to do something different.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...not technically an operation, but it's more convenient and cleaner
to pass the module pointer in this struct.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Since we now have a container for holding svc_serv operations, move the
sv_function into it as well.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In later patches we'll need to abstract out more operations on a
per-service level, besides sv_shutdown and sv_function.

Declare a new svc_serv_ops struct to hold these operations, and move
sv_shutdown into this struct.
Signed-off-by: NShirley Ma <shirley.ma@oracle.com>
Acked-by: NJeff Layton <jlayton@primarydata.com>
Tested-by: NShirley Ma <shirley.ma@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Both commit 0380a3f3 ("svcrdma: Add a separate "max data segs"
macro for svcrdma") and commit 7e5be288 ("svcrdma: advertise
the correct max payload") are incorrect. This commit reverts both
changes, restoring the server's maximum payload size to 1MB.

Commit 7e5be288 based the server's maximum payload on the
_client's_ RPCRDMA_MAX_DATA_SEGS value. That was wrong.

Commit 0380a3f3 tried to fix this so that the client maximum
payload size could be raised without affecting the server, but
managed to confuse matters more on the server side.

More importantly, limiting the advertised maximum payload size was
meant to be a workaround, not the actual fix. We need to revisit

  https://bugzilla.linux-nfs.org/show_bug.cgi?id=270

A Linux client on a platform with 64KB pages can overrun and crash
an x86_64 NFS/RDMA server when the r/wsize is 1MB. An x86/64 Linux
client seems to work fine using 1MB reads and writes when the Linux
server's maximum payload size is restored to 1MB.

BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=270
Fixes: 0380a3f3 ("svcrdma: Add a separate "max data segs" macro")
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>