Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Remove the old nfsd_for_n_state function and move nfsd_find_client
higher up into the file to get rid of forward declaration. Remove
the struct nfsd_fault_inject_op arguments from the operations as
they are no longer needed by any of them.

Finally, remove the old "standard" get and set routines, which
also eliminates the client_mutex from this code.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...instead of relying on the client_mutex.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...instead of relying on the client_mutex.

Also, fix up the printk output that is generated when the file is read.
It currently says that it's reporting the number of open files, but
it's actually reporting the number of openowners.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...instead of relying on the client_mutex.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In a later patch, we'll want to collect the locks onto a list for later
destruction. If "func" is defined and "collect" is defined, then we'll
add the lock stateid to the list.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...which uses the client_lock for protection instead of client_mutex.
Also remove nfsd_forget_client as there are no more callers.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...that relies on the client_lock instead of client_mutex.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Add a new "get" routine for forget_clients that relies on the
client_lock instead of the client_mutex.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Now that we've added more granular locking in other places, it's time
to address the fault injection code. This code is currently quite
reliant on the client_mutex for protection. Start to change this by
adding a new set of fault injection op vectors.

For now they all use the legacy ones. In later patches we'll add new
routines that can deal with more granular locking.

Also, move some of the printk routines into the callers to make the
results of the operations more uniform.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The clid counter is a global counter currently. Move it to be a per-net
property so that it can be properly protected by the nn->client_lock
instead of relying on the client_mutex.

The verifier generator is also potentially racy if there are two
simultaneous callers. Generate the verifier when we generate the clid
value, so it's also created under the client_lock. With this, there's
no need to keep two counters as they'd always be in sync anyway, so
just use the clientid_counter for both.

As Trond points out, what would be best is to eventually move this
code to use IDR instead of the hash tables. That would also help ensure
uniqueness, but that's probably best done as a separate project.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

It's possible that we'll have an in-progress call on some of the clients
while a rogue EXCHANGE_ID or DESTROY_CLIENTID call comes in. Be sure to
try and mark the client expired first, so that the refcount is
respected.

This will only be a problem once the client_mutex is removed.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

After testing nfs4 lock, I restart the nfsd service, got messages as,

[ 5677.403419] nfsd: last server has exited, flushing export cache
[ 5677.463728] =============================================================================
[ 5677.463942] BUG nfsd4_files (Tainted: G    B      OE): Objects remaining in nfsd4_files on kmem_cache_close()
[ 5677.464055] -----------------------------------------------------------------------------

[ 5677.464203] INFO: Slab 0xffffea0000233400 objects=28 used=1 fp=0xffff880008cd3d98 flags=0x3ffc0000004080
[ 5677.464318] CPU: 0 PID: 3772 Comm: rmmod Tainted: G    B      OE 3.16.0-rc2+ #29
[ 5677.464420] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 5677.464538]  0000000000000000 0000000036af2c9f ffff88000ce97d68 ffffffff816eacfa
[ 5677.464643]  ffffea0000233400 ffff88000ce97e40 ffffffff811cda44 ffffffff00000020
[ 5677.464774]  ffff88000ce97e50 ffff88000ce97e00 656a624f00000008 616d657220737463
[ 5677.464875] Call Trace:
[ 5677.464925]  [<ffffffff816eacfa>] dump_stack+0x45/0x56
[ 5677.464983]  [<ffffffff811cda44>] slab_err+0xb4/0xe0
[ 5677.465040]  [<ffffffff811d0457>] ? __kmalloc+0x117/0x290
[ 5677.465099]  [<ffffffff81100eec>] ? on_each_cpu_cond+0xac/0xf0
[ 5677.465158]  [<ffffffff811d1bc0>] ? kmem_cache_close+0x110/0x2e0
[ 5677.465218]  [<ffffffff811d1be0>] kmem_cache_close+0x130/0x2e0
[ 5677.465279]  [<ffffffff8135a0c1>] ? kobject_cleanup+0x91/0x1b0
[ 5677.465338]  [<ffffffff811d22be>] __kmem_cache_shutdown+0xe/0x10
[ 5677.465399]  [<ffffffff8119bd28>] kmem_cache_destroy+0x48/0x100
[ 5677.465466]  [<ffffffffa05ef78d>] nfsd4_free_slabs+0x2d/0x50 [nfsd]
[ 5677.465530]  [<ffffffffa05fa987>] exit_nfsd+0x34/0x6ad [nfsd]
[ 5677.465589]  [<ffffffff81104ac2>] SyS_delete_module+0x162/0x200
[ 5677.465649]  [<ffffffff81013b69>] ? do_notify_resume+0x59/0x90
[ 5677.465759]  [<ffffffff816f2369>] system_call_fastpath+0x16/0x1b
[ 5677.465822] INFO: Object 0xffff880008cd0000 @offset=0
[ 5677.465882] INFO: Allocated in nfsd4_process_open1+0x61/0x350 [nfsd] age=7599 cpu=0 pid=3253
[ 5677.466115]  __slab_alloc+0x3b0/0x4b1
[ 5677.466166]  kmem_cache_alloc+0x1e4/0x240
[ 5677.466220]  nfsd4_process_open1+0x61/0x350 [nfsd]
[ 5677.466276]  nfsd4_open+0xee/0x860 [nfsd]
[ 5677.466329]  nfsd4_proc_compound+0x4d7/0x7f0 [nfsd]
[ 5677.466384]  nfsd_dispatch+0xbb/0x200 [nfsd]
[ 5677.466447]  svc_process_common+0x453/0x6f0 [sunrpc]
[ 5677.466506]  svc_process+0x103/0x170 [sunrpc]
[ 5677.466559]  nfsd+0x117/0x190 [nfsd]
[ 5677.466609]  kthread+0xd8/0xf0
[ 5677.466656]  ret_from_fork+0x7c/0xb0
[ 5677.466775] kmem_cache_destroy nfsd4_files: Slab cache still has objects
[ 5677.466839] CPU: 0 PID: 3772 Comm: rmmod Tainted: G    B      OE 3.16.0-rc2+ #29
[ 5677.466937] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013
[ 5677.467049]  0000000000000000 0000000036af2c9f ffff88000ce97eb0 ffffffff816eacfa
[ 5677.467150]  ffff880020bb2d00 ffff88000ce97ed0 ffffffff8119bdd9 0000000000000000
[ 5677.467250]  ffffffffa06065c0 ffff88000ce97ee0 ffffffffa05ef78d ffff88000ce97ef0
[ 5677.467351] Call Trace:
[ 5677.467397]  [<ffffffff816eacfa>] dump_stack+0x45/0x56
[ 5677.467454]  [<ffffffff8119bdd9>] kmem_cache_destroy+0xf9/0x100
[ 5677.467516]  [<ffffffffa05ef78d>] nfsd4_free_slabs+0x2d/0x50 [nfsd]
[ 5677.467579]  [<ffffffffa05fa987>] exit_nfsd+0x34/0x6ad [nfsd]
[ 5677.467639]  [<ffffffff81104ac2>] SyS_delete_module+0x162/0x200
[ 5677.467765]  [<ffffffff81013b69>] ? do_notify_resume+0x59/0x90
[ 5677.467826]  [<ffffffff816f2369>] system_call_fastpath+0x16/0x1b
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NJeff Layton <jlayton@primarydata.com>
Fixes: 11b9164a "nfsd: Add a struct nfs4_file field to struct nfs4_stid"
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If it fails, it means that the client is in use and so destroying it
would be bad. Currently, the client_mutex prevents this from happening
but once we remove it, we won't be able to do this.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

All the callers except for the fault injection code call it directly
afterward, and in the fault injection case it won't hurt to do so
anyway.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Currently, it's protected by the client_mutex. Move it so that the list
and the fields in the openowner are protected by the client_lock.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Ensure that the client lookup is done safely under the client_lock, so
we're not relying on the client_mutex.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...instead of relying on the client_mutex.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In particular, we want to ensure that the move_to_confirmed() is
protected by the nn->client_lock spin lock, so that we can use that when
looking up the clientid etc. instead of relying on the client_mutex.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...instead of relying on the client_mutex.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

For efficiency reasons, and because we want to use spin locks instead
of relying on the client_mutex.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The struct nfs_client is supposed to be invisible and unreferenced
before it gets here.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If we leave the client on the confirmed/unconfirmed tables, and leave
the sessions visible on the sessionid_hashtbl, then someone might
find them before we've had a chance to destroy them.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When we remove the client_mutex protection, we will need to ensure
that it can't be found by other threads while we're destroying it.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

A memory allocation failure could cause nfsd_startup_generic to fail, in
which case nfsd_users wouldn't be incorrectly left elevated.

After nfsd restarts nfsd_startup_generic will then succeed without doing
anything--the first consequence is likely nfs4_start_net finding a bad
laundry_wq and crashing.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Fixes: 4539f149 "nfsd: replace boolean nfsd_up flag by users counter"
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

...to better match other functions that deal with open/lock stateids.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

When we remove the client_mutex, we'll have a potential race between
FREE_STATEID and CLOSE.

The root of the problem is that we are walking the st_locks list,
dropping the spinlock and then trying to release the persistent
reference to the lockstateid. In between, a FREE_STATEID call can come
along and take the lock, find the stateid and then try to put the
reference. That leads to a double put.

Fix this by not releasing the cl_lock in order to release each lock
stateid. Use put_generic_stateid_locked to unhash them and gather them
onto a list, and free_ol_stateid_reaplist to free any that end up on the
list.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Releasing an openowner is a bit inefficient as it can potentially thrash
the cl_lock if you have a lot of stateids attached to it. Once we remove
the client_mutex, it'll also potentially be dangerous to do this.

Add some functions to make it easier to defer the part of putting a
generic stateid reference that needs to be done outside the cl_lock while
doing the parts that must be done while holding it under a single lock.

First we unhash each open stateid. Then we call
put_generic_stateid_locked which will put the reference to an
nfs4_ol_stateid. If it turns out to be the last reference, it'll go
ahead and remove the stid from the IDR tree and put it onto the reaplist
using the st_locks list_head.

Then, after dropping the lock we'll call free_ol_stateid_reaplist to
walk the list of stateids that are fully unhashed and ready to be freed,
and free each of them. This function can sleep, so it must be done
outside any spinlocks.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Once we remove the client_mutex, it'll be possible for the sc_type of a
lock stateid to change after it's found and checked, but before we can
go to destroy it. If that happens, we can end up putting the persistent
reference to the stateid more than once, and unhash it more than once.

Fix this by unhashing the lock stateid prior to dropping the cl_lock but
after finding it.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Reduce the cl_lock trashing in destroy_lockowner. Unhash all of the
lockstateids on the lockowner's list. Put the reference under the lock
and see if it was the last one. If so, then add it to a private list
to be destroyed after we drop the lock.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Once we remove the client_mutex, we'll need to properly protect
the stateowner reference counts using the cl_lock.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Do more within the main loop, and simplify the function a bit. Also,
there's no need to take a stateowner reference unless we're going to call
release_lockowner.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Preparation for removing the client_mutex.

Convert the open owner hash table into a per-client table and protect it
using the nfs4_client->cl_lock spin lock.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Once we remove client mutex protection, we'll need to ensure that
stateowner lookup and creation are atomic between concurrent compounds.
Ensure that alloc_init_lock_stateowner checks the hashtable under the
client_lock before adding a new element.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Once we remove client mutex protection, we'll need to ensure that
stateowner lookup and creation are atomic between concurrent compounds.
Ensure that alloc_init_open_stateowner checks the hashtable under the
client_lock before adding a new element.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Once we remove client_mutex protection, it'll be possible to have an
in-flight operation using an openstateid when a CLOSE call comes in.
If that happens, we can't just put the sc_file reference and clear its
pointer without risking an oops.

Fix this by ensuring that v4.0 CLOSE operations wait for the refcount
to drop before proceeding to do so.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>