The fsid and chunk tree uuid are always located in the first page,
we don't need the to use write_extent_buffer.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

 __bdev' has never been used since
 0b86a832 (2008).
Signed-off-by: NDavid Sterba <dsterba@suse.com>

During the time, the function has been shrunk to the point that it just
calls find_extent_buffer, just passing the parameters.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We dereference fs_info several times, besides that post-mount functions
should never see a NULL fs_info.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The lock is held, we make the same lookup that previously failed with
EEXIST and we don't insert NULL pointers.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Originally, the eb and start were passed separately in case eb is NULL.
Since the readahead has been refactored in 4.6, this is not true anymore
and we can get rid of the parameter.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

'start' is not used since "btrfs: reada: Pass reada_extent into
__readahead_hook directly" (6e39dbe8).
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We can't touch the eb directly in case the function is called with a
non-zero error, so we can read the eb level when needed.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The helpers are not meant to be generic, the name is misleading. Convert
them to static inlines for type checking.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NDavid Sterba <dsterba@suse.com>

Fixes: ("btrfs: update btrfs_space_info's bytes_may_use timely")
Signed-off-by: NWang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

They're not even documented anywhere, letting users with no recourse but
to RTFS.  It's no big burden to output the bitfield as words.

Also, display unknown flags as hex.
Signed-off-by: NAdam Borowski <kilobyte@angband.pl>
Tested-by: NHolger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

My QEMU VM was seeing inexplicable I/O errors that I tracked down to
errors coming from the qcow2 virtual drive in the host system. The qcow2
file is a nocow file on my Btrfs drive, which QEMU opens with O_DIRECT.
Every once in awhile, pread() or pwrite() would return EEXIST, which
makes no sense. This turned out to be a bug in btrfs_get_extent().

Commit 8dff9c85 ("Btrfs: deal with duplciates during extent_map
insertion in btrfs_get_extent") fixed a case in btrfs_get_extent() where
two threads race on adding the same extent map to an inode's extent map
tree. However, if the added em is merged with an adjacent em in the
extent tree, then we'll end up with an existing extent that is not
identical to but instead encompasses the extent we tried to add. When we
call merge_extent_mapping() to find the nonoverlapping part of the new
em, the arithmetic overflows because there is no such thing. We then end
up trying to add a bogus em to the em_tree, which results in a EEXIST
that can bubble all the way up to userspace.

Fix it by extending the identical extent map special case.
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Tickets_id's name may result in some misunderstandings,  it just indicates
the next ticket will be handled and is not stored per ticket.

Fixes: ce129655 ("btrfs: introduce tickets_id to determine whether
asynchronous metadata reclaim work makes progress")
Signed-off-by: NWang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NWang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_map_block supports different types of mappings, which to a large
extent resemble block layer operations.  But they don't always do, and
currently btrfs dangerously overlays it's own flag over the block layer
flags.  This is just asking for a conflict, so introduce a different
map flags enum inside of btrfs instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Botched calculation of number of pages.  As the result,
we were dropping pieces when doing splice to pipe from
e.g. 9p.
Reported-by: NAlexei Starovoitov <ast@kernel.org>
Tested-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

While walking the list of lock_states, keep a reference on each
nfs4_lock_state to be checked, otherwise the lock state could be removed
while the check performs TEST_STATEID and possible FREE_STATEID.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the block size or cluster size is insane, reject the mount.  This
is important for security reasons (although we shouldn't be just
depending on this check).

Ref: http://www.securityfocus.com/archive/1/539661
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506Reported-by: NBorislav Petkov <bp@alien8.de>
Reported-by: NNikolay Borisov <kernel@kyup.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

With the new (in 4.9) option to use a virtually-mapped stack
(CONFIG_VMAP_STACK), stack buffers cannot be used as input/output for
the scatterlist crypto API because they may not be directly mappable to
struct page.  get_crypt_info() was using a stack buffer to hold the
output from the encryption operation used to derive the per-file key.
Fix it by using a heap buffer.

This bug could most easily be observed in a CONFIG_DEBUG_SG kernel
because this allowed the BUG in sg_set_buf() to be triggered.

Cc: stable@vger.kernel.org
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

With the new (in 4.9) option to use a virtually-mapped stack
(CONFIG_VMAP_STACK), stack buffers cannot be used as input/output for
the scatterlist crypto API because they may not be directly mappable to
struct page.  For short filenames, fname_encrypt() was encrypting a
stack buffer holding the padded filename.  Fix it by encrypting the
filename in-place in the output buffer, thereby making the temporary
buffer unnecessary.

This bug could most easily be observed in a CONFIG_DEBUG_SG kernel
because this allowed the BUG in sg_set_buf() to be triggered.

Cc: stable@vger.kernel.org
Signed-off-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Now that we're doing TEST_STATEID in nfs4_reclaim_open_state(), we can have
a NFS4ERR_OLD_STATEID returned from nfs41_open_expired() .  Instead of
marking state recovery as failed, mark the state for recovery again.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Ensure we test to see if the open stateid is actually set, before we
send a CLOSE.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the reply to a successful CLOSE call races with an OPEN to the same
file, we can end up scribbling over the stateid that represents the
new open state.
The race looks like:

  Client				Server
  ======				======

  CLOSE stateid A on file "foo"
					CLOSE stateid A, return stateid C
  OPEN file "foo"
					OPEN "foo", return stateid B
  Receive reply to OPEN
  Reset open state for "foo"
  Associate stateid B to "foo"

  Receive CLOSE for A
  Reset open state for "foo"
  Replace stateid B with C

The fix is to examine the argument of the CLOSE, and check for a match
with the current stateid "other" field. If the two do not match, then
the above race occurred, and we should just ignore the CLOSE.
Reported-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

We don't want to call nfs4_free_revoked_stateid() in the case where
the delegreturn was successful.
Reported-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The IOP_XATTR flag is set on sockfs because sockfs supports getting the
"system.sockprotoname" xattr.  Since commit 6c6ef9f2, this flag is checked for
setxattr support as well.  This is wrong on sockfs because security xattr
support there is supposed to be provided by security_inode_setsecurity.  The
smack security module relies on socket labels (xattrs).

Fix this by adding a security xattr handler on sockfs that returns
-EAGAIN, and by checking for -EAGAIN in setxattr.

We cannot simply check for -EOPNOTSUPP in setxattr because there are
filesystems that neither have direct security xattr support nor support
via security_inode_setsecurity.  A more proper fix might be to move the
call to security_inode_setsecurity into sockfs, but it's not clear to me
if that is safe: we would end up calling security_inode_post_setxattr after
that as well.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Without ".owner = THIS_MODULE" it is possible to crash the kernel
by unloading the Orangefs module while someone is reading debugfs
files.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>

If pos is at the beginning of a page and copied is zero then page is not
zeroed but is marked uptodate.

Fix by skipping everything except unlock/put of page if zero bytes were
copied.
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Fixes: 6b12c1b3 ("fuse: Implement write_begin/write_end callbacks")
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

A bugfix introduced a harmless gcc warning in nfs4_slot_seqid_in_use if
we enable -Wmaybe-uninitialized again:

  fs/nfs/nfs4session.c:203:54: error: 'cur_seq' may be used uninitialized in this function [-Werror=maybe-uninitialized]

gcc is not smart enough to conclude that the IS_ERR/PTR_ERR pair results
in a nonzero return value here.  Using PTR_ERR_OR_ZERO() instead makes
this clear to the compiler.

Fixes: e09c978a ("NFSv4.1: Fix Oopsable condition in server callback races")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It could be not possible to freeze coredumping task when it waits for
'core_state->startup' completion, because threads are frozen in
get_signal() before they got a chance to complete 'core_state->startup'.

Inability to freeze a task during suspend will cause suspend to fail.
Also CRIU uses cgroup freezer during dump operation.  So with an
unfreezable task the CRIU dump will fail because it waits for a
transition from 'FREEZING' to 'FROZEN' state which will never happen.

Use freezer_do_not_count() to tell freezer to ignore coredumping task
while it waits for core_state->startup completion.

Link: http://lkml.kernel.org/r/1475225434-3753-1-git-send-email-aryabinin@virtuozzo.comSigned-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following panic was caught when run ocfs2 disconfig single test
(block size 512 and cluster size 8192).  ocfs2_journal_dirty() return
-ENOSPC, that means credits were used up.

The total credit should include 3 times of "num_dx_leaves" from
ocfs2_dx_dir_rebalance(), because 2 times will be consumed in
ocfs2_dx_dir_transfer_leaf() and 1 time will be consumed in
ocfs2_dx_dir_new_cluster() -> __ocfs2_dx_dir_new_cluster() ->
ocfs2_dx_dir_format_cluster().  But only two times is included in
ocfs2_dx_dir_rebalance_credits(), fix it.

This can cause read-only fs(v4.1+) or panic for mainline linux depending
on mount option.

  ------------[ cut here ]------------
  kernel BUG at fs/ocfs2/journal.c:775!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: ocfs2 nfsd lockd grace nfs_acl auth_rpcgss sunrpc autofs4 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sd_mod sg ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i cxgb4 cxgb3i libcxgbi cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ppdev xen_kbdfront xen_netfront fb_sys_fops sysimgblt sysfillrect syscopyarea parport_pc parport acpi_cpufreq i2c_piix4 i2c_core pcspkr ext4 jbd2 mbcache xen_blkfront floppy pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod
  CPU: 2 PID: 10601 Comm: dd Not tainted 4.1.12-71.el6uek.bug24939243.x86_64 #2
  Hardware name: Xen HVM domU, BIOS 4.4.4OVM 02/11/2016
  task: ffff8800b6de6200 ti: ffff8800a7d48000 task.ti: ffff8800a7d48000
  RIP: ocfs2_journal_dirty+0xa7/0xb0 [ocfs2]
  RSP: 0018:ffff8800a7d4b6d8  EFLAGS: 00010286
  RAX: 00000000ffffffe4 RBX: 00000000814d0a9c RCX: 00000000000004f9
  RDX: ffffffffa008e990 RSI: ffffffffa008f1ee RDI: ffff8800622b6460
  RBP: ffff8800a7d4b6f8 R08: ffffffffa008f288 R09: ffff8800622b6460
  R10: 0000000000000000 R11: 0000000000000282 R12: 0000000002c8421e
  R13: ffff88006d0cad00 R14: ffff880092beef60 R15: 0000000000000070
  FS:  00007f9b83e92700(0000) GS:ffff8800be880000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fb2c0d1a000 CR3: 0000000008f80000 CR4: 00000000000406e0
  Call Trace:
    ocfs2_dx_dir_transfer_leaf+0x159/0x1a0 [ocfs2]
    ocfs2_dx_dir_rebalance+0xd9b/0xea0 [ocfs2]
    ocfs2_find_dir_space_dx+0xd3/0x300 [ocfs2]
    ocfs2_prepare_dx_dir_for_insert+0x219/0x450 [ocfs2]
    ocfs2_prepare_dir_for_insert+0x1d6/0x580 [ocfs2]
    ocfs2_mknod+0x5a2/0x1400 [ocfs2]
    ocfs2_create+0x73/0x180 [ocfs2]
    vfs_create+0xd8/0x100
    lookup_open+0x185/0x1c0
    do_last+0x36d/0x780
    path_openat+0x92/0x470
    do_filp_open+0x4a/0xa0
    do_sys_open+0x11a/0x230
    SyS_open+0x1e/0x20
    system_call_fastpath+0x12/0x71
  Code: 1d 3f 29 09 00 48 85 db 74 1f 48 8b 03 0f 1f 80 00 00 00 00 48 8b 7b 08 48 83 c3 10 4c 89 e6 ff d0 48 8b 03 48 85 c0 75 eb eb 90 <0f> 0b eb fe 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54
  RIP  ocfs2_journal_dirty+0xa7/0xb0 [ocfs2]
  ---[ end trace 91ac5312a6ee1288 ]---
  Kernel panic - not syncing: Fatal exception
  Kernel Offset: disabled

Link: http://lkml.kernel.org/r/1478248135-31963-1-git-send-email-junxiao.bi@oracle.comSigned-off-by: NJunxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

i_size check is a leftover from the horrors that used to play with
the page cache in that function.  With the switch to ->read_iter(),
it's neither needed nor correct - for gfs2 it ends up being buggy,
since i_size is not guaranteed to be correct until later (inside
->read_iter()).
Spotted-by: NAbhi Das <adas@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Splice read/write implementation changed recently. When using
generic_file_splice_read(), iov_iter with type == ITER_PIPE is
passed to filesystem's read_iter callback. But ceph_sync_read()
can't serve ITER_PIPE iov_iter correctly (ITER_PIPE iov_iter
expects pages from page cache).

Fixing ceph_sync_read() requires a big patch. So use default
splice read callback for now.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Fix the following warn:

fs/nfs/nfs4session.c: In function ‘nfs4_slot_seqid_in_use’:
fs/nfs/nfs4session.c:203:54: warning: ‘cur_seq’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (nfs4_slot_get_seqid(tbl, slotid, &cur_seq) == 0 &&
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
      cur_seq == seq_nr && test_bit(slotid, tbl->used_slots))
      ~~~~~~~~~~~~~~~~~
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

We used to check for a valid layout type id before verifying pNFS flags
as an indicator for if we are using pNFS.  This changed in 3132e49e
with the introduction of multiple layout types, since now we are passing
an array of ids instead of just one.  Since then, users have been seeing
a KERN_ERR printk show up whenever mounting NFS v4 without pNFS.  This
patch restores the original behavior of exiting set_pnfs_layoutdriver()
early if we aren't using pNFS.

Fixes 3132e49e ("pnfs: track multiple layout types in fsinfo
structure")
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

cl_rpcclient starts as ERR_PTR(-EINVAL), and connections like that
are floating freely through the system.  Most places check whether
pointer is valid before dereferencing it, but newly added code
in nfs_match_client does not.

Which causes crashes when more than one NFS mount point is present.
Signed-off-by: NPetr Vandrovec <petr@vandrovec.name>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

We recently refactored the Orangefs debugfs code.
The refactor seemed to trigger dan.carpenter@oracle.com's
static tester to find a possible double-free in the code.

While designing the fix we saw a condition under which the
buffer being freed could also be overflowed.

We also realized how to rebuild the related debugfs file's
"contents" (a string) without deleting and re-creating the file.

This fix should eliminate the possible double-free, the
potential overflow and improve code readability.
Signed-off-by: NMike Marshall <hubcap@omnibond.com>
Signed-off-by: NMartin Brandenburg <martin@omnibond.com>

When I push NFSv4.1 / RDMA hard, (xfstests generic/089, for example),
I get this crash on the server:

Oct 28 22:04:30 klimt kernel: general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Oct 28 22:04:30 klimt kernel: Modules linked in: cts rpcsec_gss_krb5 iTCO_wdt iTCO_vendor_support sb_edac edac_core x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm btrfs irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd xor pcspkr raid6_pq i2c_i801 i2c_smbus lpc_ich mfd_core sg mei_me mei ioatdma shpchp wmi ipmi_si ipmi_msghandler rpcrdma ib_ipoib rdma_ucm acpi_power_meter acpi_pad ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c mlx4_ib mlx4_en ib_core sr_mod cdrom sd_mod ast drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm crc32c_intel igb ahci libahci ptp mlx4_core pps_core dca libata i2c_algo_bit i2c_core dm_mirror dm_region_hash dm_log dm_mod
Oct 28 22:04:30 klimt kernel: CPU: 7 PID: 1558 Comm: nfsd Not tainted 4.9.0-rc2-00005-g82cd754 #8
Oct 28 22:04:30 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Oct 28 22:04:30 klimt kernel: task: ffff880835c3a100 task.stack: ffff8808420d8000
Oct 28 22:04:30 klimt kernel: RIP: 0010:[<ffffffffa05a759f>]  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP: 0018:ffff8808420dbce0  EFLAGS: 00010246
Oct 28 22:04:30 klimt kernel: RAX: ffff88084e6660f0 RBX: ffff88084e667020 RCX: 0000000000000000
Oct 28 22:04:30 klimt kernel: RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff88084e667020
Oct 28 22:04:30 klimt kernel: RBP: ffff8808420dbcf8 R08: 0000000000000001 R09: 0000000000000000
Oct 28 22:04:30 klimt kernel: R10: ffff880835c3a100 R11: ffff880835c3aca8 R12: 6b6b6b6b6b6b6b6b
Oct 28 22:04:30 klimt kernel: R13: ffff88084e6670d8 R14: ffff880835f546f0 R15: ffff880835f1c548
Oct 28 22:04:30 klimt kernel: FS:  0000000000000000(0000) GS:ffff88087bdc0000(0000) knlGS:0000000000000000
Oct 28 22:04:30 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 28 22:04:30 klimt kernel: CR2: 00007ff020389000 CR3: 0000000001c06000 CR4: 00000000001406e0
Oct 28 22:04:30 klimt kernel: Stack:
Oct 28 22:04:30 klimt kernel: ffff88084e667020 0000000000000000 ffff88084e6670d8 ffff8808420dbd20
Oct 28 22:04:30 klimt kernel: ffffffffa05ac80d ffff880835f54548 ffff88084e640008 ffff880835f545b0
Oct 28 22:04:30 klimt kernel: ffff8808420dbd70 ffffffffa059803d ffff880835f1c768 0000000000000870
Oct 28 22:04:30 klimt kernel: Call Trace:
Oct 28 22:04:30 klimt kernel: [<ffffffffa05ac80d>] nfsd4_free_stateid+0xfd/0x1b0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa059803d>] nfsd4_proc_compound+0x40d/0x690 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa0583114>] nfsd_dispatch+0xd4/0x1d0 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047bbf9>] svc_process_common+0x3d9/0x700 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa047ca64>] svc_process+0xf4/0x330 [sunrpc]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05827ca>] nfsd+0xfa/0x160 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffffa05826d0>] ? nfsd_destroy+0x170/0x170 [nfsd]
Oct 28 22:04:30 klimt kernel: [<ffffffff810b367b>] kthread+0x10b/0x120
Oct 28 22:04:30 klimt kernel: [<ffffffff810b3570>] ? kthread_stop+0x280/0x280
Oct 28 22:04:30 klimt kernel: [<ffffffff8174e8ba>] ret_from_fork+0x2a/0x40
Oct 28 22:04:30 klimt kernel: Code: c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 41 54 53 48 8b 87 b0 00 00 00 48 89 fb 4c 8b a0 98 00 00 00 <49> 8b 44 24 20 48 8d b8 80 03 00 00 e8 10 66 1a e1 48 89 df e8
Oct 28 22:04:30 klimt kernel: RIP  [<ffffffffa05a759f>] release_lock_stateid+0x1f/0x60 [nfsd]
Oct 28 22:04:30 klimt kernel: RSP <ffff8808420dbce0>
Oct 28 22:04:30 klimt kernel: ---[ end trace cf5d0b371973e167 ]---

Jeff Layton says:
> Hm...now that I look though, this is a little suspicious:
>
>    struct nfs4_openowner *oo = openowner(stp->st_openstp->st_stateowner);
>
> I wonder if it's possible for the openstateid to have already been
> destroyed at this point.
>
> We might be better off doing something like this to get the client pointer:
>
>    stp->st_stid.sc_client;
>
> ...which should be more direct and less dependent on other stateids
> staying valid.

With the suggested change, I am no longer able to reproduce the above oops.

v2: Fix unhash_lock_stateid() as well
Fix-suggested-by: NJeff Layton <jlayton@redhat.com>
Fixes: 42691398 ('nfsd: Fix race between FREE_STATEID and LOCK')
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>