Close an attack vector by moving the arrays of per-server methods to
read-only memory.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We want to use kthread_stop() in order to ensure the threads are
shut down before we tear down the nfs_callback_info in nfs_callback_down.
Tested-and-reviewed-by: NKinglong Mee <kinglongmee@gmail.com>
Reported-by: NKinglong Mee <kinglongmee@gmail.com>
Fixes: bb6aeba7 ("NFSv4.x: Switch to using svc_set_num_threads()...")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

As the comments for svc_set_num_threads() said,
" Destroying threads relies on the service threads filling in
rqstp->rq_task, which only the nfs ones do.  Assumes the serv
has been created using svc_create_pooled()."

If creating service through svc_create(), the svc_pool_map_put()
will be called in svc_destroy(), but the pool map isn't used.
So that, the reference of pool map will be drop, the next using
of pool map will get a zero npools.

[  137.992130] divide error: 0000 [#1] SMP
[  137.992148] Modules linked in: nfsd(E) nfsv4 nfs fscache fuse tun bridge stp llc ip_set nfnetlink vmw_vsock_vmci_transport vsock snd_seq_midi snd_seq_midi_event vmw_balloon coretemp crct10dif_pclmul crc32_pclmul ppdev ghash_clmulni_intel intel_rapl_perf joydev snd_ens1371 gameport snd_ac97_codec ac97_bus snd_seq snd_pcm snd_rawmidi snd_timer snd_seq_device snd soundcore parport_pc parport nfit acpi_cpufreq tpm_tis tpm_tis_core tpm vmw_vmci i2c_piix4 shpchp auth_rpcgss nfs_acl lockd(E) grace sunrpc(E) xfs libcrc32c vmwgfx drm_kms_helper ttm crc32c_intel drm e1000 mptspi scsi_transport_spi serio_raw mptscsih mptbase ata_generic pata_acpi [last unloaded: nfsd]
[  137.992336] CPU: 0 PID: 4514 Comm: rpc.nfsd Tainted: G            E   4.11.0-rc8+ #536
[  137.992777] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
[  137.993757] task: ffff955984101d00 task.stack: ffff9873c2604000
[  137.994231] RIP: 0010:svc_pool_for_cpu+0x2b/0x80 [sunrpc]
[  137.994768] RSP: 0018:ffff9873c2607c18 EFLAGS: 00010246
[  137.995227] RAX: 0000000000000000 RBX: ffff95598376f000 RCX: 0000000000000002
[  137.995673] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9559944aec00
[  137.996156] RBP: ffff9873c2607c18 R08: ffff9559944aec28 R09: 0000000000000000
[  137.996609] R10: 0000000001080002 R11: 0000000000000000 R12: ffff95598376f010
[  137.997063] R13: ffff95598376f018 R14: ffff9559944aec28 R15: ffff9559944aec00
[  137.997584] FS:  00007f755529eb40(0000) GS:ffff9559bb600000(0000) knlGS:0000000000000000
[  137.998048] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  137.998548] CR2: 000055f3aecd9660 CR3: 0000000084290000 CR4: 00000000001406f0
[  137.999052] Call Trace:
[  137.999517]  svc_xprt_do_enqueue+0xef/0x260 [sunrpc]
[  138.000028]  svc_xprt_received+0x47/0x90 [sunrpc]
[  138.000487]  svc_add_new_perm_xprt+0x76/0x90 [sunrpc]
[  138.000981]  svc_addsock+0x14b/0x200 [sunrpc]
[  138.001424]  ? recalc_sigpending+0x1b/0x50
[  138.001860]  ? __getnstimeofday64+0x41/0xd0
[  138.002346]  ? do_gettimeofday+0x29/0x90
[  138.002779]  write_ports+0x255/0x2c0 [nfsd]
[  138.003202]  ? _copy_from_user+0x4e/0x80
[  138.003676]  ? write_recoverydir+0x100/0x100 [nfsd]
[  138.004098]  nfsctl_transaction_write+0x48/0x80 [nfsd]
[  138.004544]  __vfs_write+0x37/0x160
[  138.004982]  ? selinux_file_permission+0xd7/0x110
[  138.005401]  ? security_file_permission+0x3b/0xc0
[  138.005865]  vfs_write+0xb5/0x1a0
[  138.006267]  SyS_write+0x55/0xc0
[  138.006654]  entry_SYSCALL_64_fastpath+0x1a/0xa9
[  138.007071] RIP: 0033:0x7f7554b9dc30
[  138.007437] RSP: 002b:00007ffc9f92c788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  138.007807] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f7554b9dc30
[  138.008168] RDX: 0000000000000002 RSI: 00005640cd536640 RDI: 0000000000000003
[  138.008573] RBP: 00007ffc9f92c780 R08: 0000000000000001 R09: 0000000000000002
[  138.008918] R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000004
[  138.009254] R13: 00005640cdbf77a0 R14: 00005640cdbf7720 R15: 00007ffc9f92c238
[  138.009610] Code: 0f 1f 44 00 00 48 8b 87 98 00 00 00 55 48 89 e5 48 83 78 08 00 74 10 8b 05 07 42 02 00 83 f8 01 74 40 83 f8 02 74 19 31 c0 31 d2 <f7> b7 88 00 00 00 5d 89 d0 48 c1 e0 07 48 03 87 90 00 00 00 c3
[  138.010664] RIP: svc_pool_for_cpu+0x2b/0x80 [sunrpc] RSP: ffff9873c2607c18
[  138.011061] ---[ end trace b3468224cafa7d11 ]---
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Fixes the following sparse warning:

fs/nfs/callback.c:235:21: warning: symbol 'nfs4_cb_sv_ops' was not
declared. Should it be static?
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

A correct bugfix introduced a harmless warning that shows up with gcc-7:

fs/nfs/callback.c: In function 'nfs_callback_up':
fs/nfs/callback.c:214:14: error: array subscript is outside array bounds [-Werror=array-bounds]

What happens here is that the 'minorversion == 0' check tells the
compiler that we assume minorversion can be something other than 0,
but when CONFIG_NFS_V4_1 is disabled that would be invalid and
result in an out-of-bounds access.

The added check for IS_ENABLED(CONFIG_NFS_V4_1) tells gcc that this
really can't happen, which makes the code slightly smaller and also
avoids the warning.

The bugfix that introduced the warning is marked for stable backports,
we want this one backported to the same releases.

Fixes: 98b0f80c ("NFSv4.x: Fix a refcount leak in nfs_callback_up_net")
Cc: stable@vger.kernel.org # v3.7+
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Add support for the kernel parameter nfs.callback_nr_threads to set
the number of threads that will be assigned to the callback channel.

Add support for the kernel parameter nfs.nfs.max_session_cb_slots
to set the maximum size of the callback channel slot table.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This will allow us to bump the number of callback threads at will.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Ensure that the nfs_callback_info[] array correctly tracks the
struct svc_serv.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Clean up.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

In order to manage the threads using svc_set_num_threads, we need to
fill in a few extra fields.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

On error, the callers expect us to return without bumping
nn->cb_users[].
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v3.7+

Forechannel transports get their own "bc_up" method to create an
endpoint for the backchannel service.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
[Anna Schumaker: Add forward declaration of struct net to xprt.h]
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The xprt created by svc_create_xprt have be added to serv->sv_permsocks.
So putting the xprt directly is useless.
Otherwise, there is a more svc_xprt_put after the xprt be freed.

v2, same as v1.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.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>

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>

A drop should really only be done when the frame is malformed or we have
reason to think that there is some sort of DoS going on. When we get an
RPC with bad auth, we should send back an error instead.

Cc: Andy Adamson <William.Adamson@netapp.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Chuck pointed out a problem that crept in with commit 6ffa30d3 (nfs:
don't call blocking operations while !TASK_RUNNING). Linux counts tasks
in uninterruptible sleep against the load average, so this caused the
system's load average to be pinned at at least 1 when there was a
NFSv4.1+ mount active.

Not a huge problem, but it's probably worth fixing before we get too
many complaints about it. This patch converts the code back to use
TASK_INTERRUPTIBLE sleep, simply has it flush any signals on each loop
iteration. In practice no one should really be signalling this thread at
all, so I think this is reasonably safe.

With this change, there's also no need to game the hung task watchdog so
we can also convert the schedule_timeout call back to a normal schedule.

Cc: <stable@vger.kernel.org>
Reported-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Tested-by: NChuck Lever <chuck.lever@oracle.com>
Fixes: commit 6ffa30d3 (“nfs: don't call blocking . . .”)
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Bruce reported seeing this warning pop when mounting using v4.1:

     ------------[ cut here ]------------
     WARNING: CPU: 1 PID: 1121 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()
    do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff810ff58f>] prepare_to_wait+0x2f/0x90
    Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer ppdev joydev snd virtio_console virtio_balloon pcspkr serio_raw parport_pc parport pvpanic floppy soundcore i2c_piix4 virtio_blk virtio_net qxl drm_kms_helper ttm drm virtio_pci virtio_ring ata_generic virtio pata_acpi
    CPU: 1 PID: 1121 Comm: nfsv4.1-svc Not tainted 3.19.0-rc4+ #25
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153950- 04/01/2014
     0000000000000000 000000004e5e3f73 ffff8800b998fb48 ffffffff8186ac78
     0000000000000000 ffff8800b998fba0 ffff8800b998fb88 ffffffff810ac9da
     ffff8800b998fb68 ffffffff81c923e7 00000000000004d9 0000000000000000
    Call Trace:
     [<ffffffff8186ac78>] dump_stack+0x4c/0x65
     [<ffffffff810ac9da>] warn_slowpath_common+0x8a/0xc0
     [<ffffffff810aca65>] warn_slowpath_fmt+0x55/0x70
     [<ffffffff810ff58f>] ? prepare_to_wait+0x2f/0x90
     [<ffffffff810ff58f>] ? prepare_to_wait+0x2f/0x90
     [<ffffffff810dd2ad>] __might_sleep+0xbd/0xd0
     [<ffffffff8124c973>] kmem_cache_alloc_trace+0x243/0x430
     [<ffffffff810d941e>] ? groups_alloc+0x3e/0x130
     [<ffffffff810d941e>] groups_alloc+0x3e/0x130
     [<ffffffffa0301b1e>] svcauth_unix_accept+0x16e/0x290 [sunrpc]
     [<ffffffffa0300571>] svc_authenticate+0xe1/0xf0 [sunrpc]
     [<ffffffffa02fc564>] svc_process_common+0x244/0x6a0 [sunrpc]
     [<ffffffffa02fd044>] bc_svc_process+0x1c4/0x260 [sunrpc]
     [<ffffffffa03d5478>] nfs41_callback_svc+0x128/0x1f0 [nfsv4]
     [<ffffffff810ff970>] ? wait_woken+0xc0/0xc0
     [<ffffffffa03d5350>] ? nfs4_callback_svc+0x60/0x60 [nfsv4]
     [<ffffffff810d45bf>] kthread+0x11f/0x140
     [<ffffffff810ea815>] ? local_clock+0x15/0x30
     [<ffffffff810d44a0>] ? kthread_create_on_node+0x250/0x250
     [<ffffffff81874bfc>] ret_from_fork+0x7c/0xb0
     [<ffffffff810d44a0>] ? kthread_create_on_node+0x250/0x250
    ---[ end trace 675220a11e30f4f2 ]---

nfs41_callback_svc does most of its work while in TASK_INTERRUPTIBLE,
which is just wrong. Fix that by finishing the wait immediately if we've
found that the list has something on it.

Also, we don't expect this kthread to accept signals, so we should be
using a TASK_UNINTERRUPTIBLE sleep instead. That however, opens us up
hung task warnings from the watchdog, so have the schedule_timeout
wake up every 60s if there's no callback activity.
Reported-by: N"J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This fixes an Oopsable race when starting up the callback server.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-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: NJ. Bruce Fields <bfields@redhat.com>

The current CB_COMPOUND handling code tries to compare the principal
name of the request with the cl_hostname in the client. This is not
guaranteed to ever work, particularly if the client happened to mount
a CNAME of the server or a non-fqdn.

Fix this by instead comparing the cr_principal string with the acceptor
name that we get from gssd. In the event that gssd didn't send one
down (i.e. it was too old), then we fall back to trying to use the
cl_hostname as we do today.
Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Use 'PTR_ERR_OR_ZERO()' rather than 'IS_ERR(...) ? PTR_ERR(...) : 0'.
Signed-off-by: NGeyslan G. Bem <geyslan@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Calling kthread_run with a single name parameter causes it to be handled
as a format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This enable NFSv4.2 support. To enable this code the
CONFIG_NFS_V4_2 Kconfig define needs to be set and
the -o v4.2 mount option need to be used.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The v4.1 callback thread has set_freezable() at the top, but it doesn't
ever try to freeze within the loop. Have it call try_to_freeze() at the
top of the loop. If a freeze event occurs, recheck kthread_should_stop()
after thawing.
Reported-by: NYanchuan Nian <ycnian@gmail.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

returning PTR_ERR(cb_info->task) just after we have set it to
NULL looks like a typo...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>

The current spaghetti code confuses some versions of gcc (and just
looks ugly as hell)! Clean up...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch also introduces refcount-aware nfs_callback_down_net() wrapper for
svc_shutdown_net().
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Usage coutner now increased only is the service was started sccessfully.
Even if service is running already, then goto is not required anymore, because
service creation and start will be skipped.
With this patch code looks clearer.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This is just a code move, which from my POW makes code looks better.
I.e. now on start we have 3 different stages:
1) Service creation.
2) Service per-net data allocation.
3) Service start.

Patch also renames goto label "out_err:" into "err_start:" to reflect new
changes.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

No need to assign transports backchannel server explicitly in
nfs41_callback_up() -  there is nfs_callback_bc_serv() function for this.
By using it, nfs4_callback_up() and nfs41_callback_up() can be called without
transport argument.

Note: service have to be passed to nfs_callback_bc_serv() instead of callback,
since callback link can be uninitialized.
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

v4:
1) Callback transport creation routine selection by version simlified.

This new function in now called before nfs_minorversion_callback_svc_setup()).

Also few small changes:
1) current network namespace in nfs_callback_up() was replaced by transport net.
2) svc_shutdown_net() was moved prior to callback usage counter decrement
(because in case of per-net data allocation faulure svc_shutdown_net() have to
be skipped).
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This function creates service if it's not exist, or increase usage counter of
the existent, and returns pointer to it.
Usage counter will be droppepd by svc_destroy() later in nfs_callback_up().
Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>