commit 62e2a47cea upstream.
When the server is recalling a layout, we should ignore the count of
outstanding layoutget calls, since the server is expected to return
either NFS4ERR_RECALLCONFLICT or NFS4ERR_RETURNCONFLICT for as long as
the recall is outstanding.
Currently, we may end up livelocking, causing the layout to eventually
be forcibly revoked.
Fixes: bf0291dd22 ("pNFS: Ensure LAYOUTGET and LAYOUTRETURN are properly serialised")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 52cb7f8f17 ]
When exporting only one file system with fsid=0 on the server side, the
client alternately uses the ro/rw mount options to perform the mount
operation, and a new vfsmount is generated each time.
It can be reproduced as follows:
[root@localhost ~]# mount /dev/sda /mnt2
[root@localhost ~]# echo "/mnt2 *(rw,no_root_squash,fsid=0)" >/etc/exports
[root@localhost ~]# systemctl restart nfs-server
[root@localhost ~]# mount -t nfs -o ro,vers=4 127.0.0.1:/ /mnt/sdaa
[root@localhost ~]# mount -t nfs -o rw,vers=4 127.0.0.1:/ /mnt/sdaa
[root@localhost ~]# mount -t nfs -o ro,vers=4 127.0.0.1:/ /mnt/sdaa
[root@localhost ~]# mount -t nfs -o rw,vers=4 127.0.0.1:/ /mnt/sdaa
[root@localhost ~]# mount | grep nfs4
127.0.0.1:/ on /mnt/sdaa type nfs4 (ro,relatime,vers=4.2,rsize=1048576,...
127.0.0.1:/ on /mnt/sdaa type nfs4 (rw,relatime,vers=4.2,rsize=1048576,...
127.0.0.1:/ on /mnt/sdaa type nfs4 (ro,relatime,vers=4.2,rsize=1048576,...
127.0.0.1:/ on /mnt/sdaa type nfs4 (rw,relatime,vers=4.2,rsize=1048576,...
[root@localhost ~]#
We expected that after mounting with the ro option, using the rw option to
mount again would return EBUSY, but the actual situation was not the case.
As shown above, when mounting for the first time, a superblock with the ro
flag will be generated, and at the same time, in do_new_mount_fc -->
do_add_mount, it detects that the superblock corresponding to the current
target directory is inconsistent with the currently generated one
(path->mnt->mnt_sb != newmnt->mnt.mnt_sb), and a new vfsmount will be
generated.
When mounting with the rw option for the second time, since no matching
superblock can be found in the fs_supers list, a new superblock with the
rw flag will be generated again. The superblock in use (ro) is different
from the newly generated superblock (rw), and a new vfsmount will be
generated again.
When mounting with the ro option for the third time, the superblock (ro)
is found in fs_supers, the superblock in use (rw) is different from the
found superblock (ro), and a new vfsmount will be generated again.
We can switch between ro/rw through remount, and only one superblock needs
to be generated, thus avoiding the problem of repeated generation of
vfsmount caused by switching superblocks.
Furthermore, This can also resolve the issue described in the link.
Fixes: 275a5d24bf ("NFS: Error when mounting the same filesystem with different options")
Link: https://lore.kernel.org/all/20240604112636.236517-3-lilingfeng@huaweicloud.com/
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2fdb05dc09 ]
Yang Erkun reports that when two threads are opening files at the same
time, and are forced to abort before a reply is seen, then the call to
nfs_release_seqid() in nfs4_opendata_free() can result in a
use-after-free of the pointer to the defunct rpc task of the other
thread.
The fix is to ensure that if the RPC call is aborted before the call to
nfs_wait_on_sequence() is complete, then we must call nfs_release_seqid()
in nfs4_open_release() before the rpc_task is freed.
Reported-by: Yang Erkun <yangerkun@huawei.com>
Fixes: 24ac23ab88 ("NFSv4: Convert open() into an asynchronous RPC call")
Reviewed-by: Yang Erkun <yangerkun@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 867da60d46 ]
Multi-threaded buffered reads to the same file exposed significant
inode spinlock contention in nfs_clear_invalid_mapping().
Eliminate this spinlock contention by checking flags without locking,
instead using smp_rmb and smp_load_acquire accordingly, but then take
spinlock and double-check these inode flags.
Also refactor nfs_set_cache_invalid() slightly to use
smp_store_release() to pair with nfs_clear_invalid_mapping()'s
smp_load_acquire().
While this fix is beneficial for all multi-threaded buffered reads
issued by an NFS client, this issue was identified in the context of
surprisingly low LOCALIO performance with 4K multi-threaded buffered
read IO. This fix dramatically speeds up LOCALIO performance:
before: read: IOPS=1583k, BW=6182MiB/s (6482MB/s)(121GiB/20002msec)
after: read: IOPS=3046k, BW=11.6GiB/s (12.5GB/s)(232GiB/20001msec)
Fixes: 17dfeb9113 ("NFS: Fix races in nfs_revalidate_mapping")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3db63daabe ]
NFSv3 includes pre/post wcc attributes which allow the client to
determine if all changes to the file have been made by the client
itself, or if any might have been made by some other client.
If there are gaps in the pre/post ctime sequence it must be assumed that
some other client changed the file in that gap and the local cache must
be suspect. The next time the file is opened the cache should be
invalidated.
Since Commit 1c341b7775 ("NFS: Add deferred cache invalidation for
close-to-open consistency violations") in linux 5.3 the Linux client has
been triggering this invalidation. The chunk in nfs_update_inode() in
particularly triggers.
Unfortunately Linux NFS assumes that all replies will be processed in
the order sent, and will arrive in the order processed. This is not
true in general. Consequently Linux NFS might ignore the wcc info in a
WRITE reply because the reply is in response to a WRITE that was sent
before some other request for which a reply has already been seen. This
is detected by Linux using the gencount tests in nfs_inode_attr_cmp().
Also, when the gencount tests pass it is still possible that the request
were processed on the server in a different order, and a gap seen in
the ctime sequence might be filled in by a subsequent reply, so gaps
should not immediately trigger delayed invalidation.
The net result is that writing to a server and then reading the file
back can result in going to the server for the read rather than serving
it from cache - all because a couple of replies arrived out-of-order.
This is a performance regression over kernels before 5.3, though the
change in 5.3 is a correctness improvement.
This has been seen with Linux writing to a Netapp server which
occasionally re-orders requests. In testing the majority of requests
were in-order, but a few (maybe 2 or three at a time) could be
re-ordered.
This patch addresses the problem by recording any gaps seen in the
pre/post ctime sequence and not triggering invalidation until either
there are too many gaps to fit in the table, or until there are no more
active writes and the remaining gaps cannot be resolved.
We allocate a table of 16 gaps on demand. If the allocation fails we
revert to current behaviour which is of little cost as we are unlikely
to be able to cache the writes anyway.
In the table we store "start->end" pair when iversion is updated and
"end<-start" pairs pre/post pairs reported by the server. Usually these
exactly cancel out and so nothing is stored. When there are
out-of-order replies we do store gaps and these will eventually be
cancelled against later replies when this client is the only writer.
If the final write is out-of-order there may be one gap remaining when
the file is closed. This will be noticed and if there is precisely on
gap and if the iversion can be advanced to match it, then we do so.
This patch makes no attempt to handle directories correctly. The same
problem potentially exists in the out-of-order replies to create/unlink
requests can cause future lookup requires to be sent to the server
unnecessarily. A similar scheme using the same primitives could be used
to notice and handle out-of-order replies.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Stable-dep-of: 867da60d46 ("nfs: avoid i_lock contention in nfs_clear_invalid_mapping")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6e2a10343e ]
If a timeout is specified in the mount options, it currently applies to
both the NFS protocol and (with v3) the MOUNT protocol. This is
sensible when they both use the same underlying protocol, or those
protocols are compatible w.r.t timeouts as RDMA and TCP are.
However if, for example, NFS is using TCP and MOUNT is using UDP then
using the same timeout doesn't make much sense.
If you
mount -o vers=3,proto=tcp,mountproto=udp,timeo=600,retrans=5 \
server:/path /mountpoint
then the timeo=600 which was intended for the NFS/TCP request will
apply to the MOUNT/UDP requests with the result that there will only be
one request sent (because UDP has a maximum timeout of 60 seconds).
This is not what a reasonable person might expect.
This patch disables the sharing of timeout information in cases where
the underlying protocols are not compatible.
Fixes: c9301cb35b ("nfs: hornor timeo and retrans option when mounting NFSv3")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ef6010806 ]
After the delegation is returned to the NFS server remove it
from the server's delegations list to reduce the time it takes
to scan this list.
Network trace captured while running the below script shows the
time taken to service the CB_RECALL increases gradually due to
the overhead of traversing the delegation list in
nfs_delegation_find_inode_server.
The NFS server in this test is a Solaris server which issues
CB_RECALL when receiving the all-zero stateid in the SETATTR.
mount=/mnt/data
for i in $(seq 1 20)
do
echo $i
mkdir $mount/testtarfile$i
time tar -C $mount/testtarfile$i -xf 5000_files.tar
done
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6dbf1f341b ]
The math in "rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t)" could have an
integer overflow. Add bounds checking on rc_list->rcl_nrefcalls to fix
that.
Fixes: 4aece6a19c ("nfs41: cb_sequence xdr implementation")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8f6a7c9467 upstream.
Commit c77e22834a ("NFSv4: Fix a potential sleep while atomic in
nfs4_do_reclaim()") separate out the freeing of the state owners from
nfs4_purge_state_owners() and finish it outside the rcu lock.
However, the error path is omitted. As a result, the state owners in
"freeme" will not be released.
Fix it by adding freeing in the error path.
Fixes: c77e22834a ("NFSv4: Fix a potential sleep while atomic in nfs4_do_reclaim()")
Signed-off-by: Li Lingfeng <lilingfeng3@huawei.com>
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f92214e4c3 ]
If the call to nfs_delegation_grab_inode() fails, we will not have
dropped any locks that require us to rescan the list.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d72b796311 ]
Make sure that we clear the layout segments in cases where we see a
fatal error, and also in the case where the layout is invalid.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2fdbc20036 ]
If pnfsd_update_layout() is called on a file for which recovery has
failed it will enter a tight infinite loop.
NFS_LAYOUT_INVALID_STID will be set, nfs4_select_rw_stateid() will
return -EIO, and nfs4_schedule_stateid_recovery() will do nothing, so
nfs4_client_recover_expired_lease() will not wait. So the code will
loop indefinitely.
Break the loop by testing the validity of the open stateid at the top of
the loop.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a2214ed588 ]
A lot of places are setting a blank svc_stats in ->pg_stats and never
utilizing these stats. Remove all of these extra structs as we're not
reporting these stats anywhere.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4840c00003 ]
Previously in order to mark the communication with the DS server,
we tried to use NFS_CS_DS in cl_flags. However, this flag would
only be saved for the DS server and in case where DS equals MDS,
the client would not find a matching nfs_client in nfs_match_client
that represents the MDS (but is also a DS).
Instead, don't rely on the NFS_CS_DS but instead use NFS_CS_PNFS.
Fixes: 379e4adfdd ("NFSv4.1: fixup use EXCHGID4_FLAG_USE_PNFS_DS for DS server")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0c8c7c5597 ]
This is a slight variation on a patch previously proposed by Neil Brown
that never got merged.
Prior to commit 5ceb9d7fda ("NFS: Refactor nfs_lookup_revalidate()"),
any error from nfs_lookup_verify_inode() other than -ESTALE would result
in nfs_lookup_revalidate() returning that error (-ESTALE is mapped to
zero).
Since that commit, all errors result in nfs_lookup_revalidate()
returning zero, resulting in dentries being invalidated where they
previously were not (particularly in the case of -ERESTARTSYS).
Fix it by passing the actual error code to nfs_lookup_revalidate_done(),
and leaving the decision on whether to map the error code to zero or
one to nfs_lookup_revalidate_done().
A simple reproducer is to run the following python code in a
subdirectory of an NFS mount (not in the root of the NFS mount):
---8<---
import os
import multiprocessing
import time
if __name__=="__main__":
multiprocessing.set_start_method("spawn")
count = 0
while True:
try:
os.getcwd()
pool = multiprocessing.Pool(10)
pool.close()
pool.terminate()
count += 1
except Exception as e:
print(f"Failed after {count} iterations")
print(e)
break
---8<---
Prior to commit 5ceb9d7fda, the above code would run indefinitely.
After commit 5ceb9d7fda, it fails almost immediately with -ENOENT.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 134d0b3f24 ]
There is an inherent race where a symlink file may have been overriden
(by a different client) between lookup and readlink, resulting in a
spurious EIO error returned to userspace. Fix this by propagating back
ESTALE errors such that the vfs will retry the lookup/get_link (similar
to nfs4_file_open) at least once.
Cc: Dan Aloni <dan.aloni@vastdata.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aad11473f8 ]
We leak nfs_fattr and nfs4_label every time we set a security xattr.
Signed-off-by: Dmitry Mastykin <mastichi@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 54e7d59841 upstream.
Since commit 2282679fb2 ("mm: submit multipage write for SWP_FS_OPS
swap-space"), we can plug multiple pages then unplug them all together.
That means iov_iter_count(iter) could be way bigger than PAGE_SIZE, it
actually equals the size of iov_iter_npages(iter, INT_MAX).
Note this issue has nothing to do with large folios as we don't support
THP_SWPOUT to non-block devices.
[v-songbaohua@oppo.com: figure out the cause and correct the commit message]
Link: https://lkml.kernel.org/r/20240618065647.21791-1-21cnbao@gmail.com
Fixes: 2282679fb2 ("mm: submit multipage write for SWP_FS_OPS swap-space")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Closes: https://lore.kernel.org/linux-mm/20240617053201.GA16852@lst.de/
Reviewed-by: Martin Wege <martin.l.wege@gmail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Steve French <sfrench@samba.org>
Cc: Trond Myklebust <trondmy@kernel.org>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 99bc9f2eb3 ]
dentry->d_fsdata is set to NFS_FSDATA_BLOCKED while unlinking or
renaming-over a file to ensure that no open succeeds while the NFS
operation progressed on the server.
Setting dentry->d_fsdata to NFS_FSDATA_BLOCKED is done under ->d_lock
after checking the refcount is not elevated. Any attempt to open the
file (through that name) will go through lookp_open() which will take
->d_lock while incrementing the refcount, we can be sure that once the
new value is set, __nfs_lookup_revalidate() *will* see the new value and
will block.
We don't have any locking guarantee that when we set ->d_fsdata to NULL,
the wait_var_event() in __nfs_lookup_revalidate() will notice.
wait/wake primitives do NOT provide barriers to guarantee order. We
must use smp_load_acquire() in wait_var_event() to ensure we look at an
up-to-date value, and must use smp_store_release() before wake_up_var().
This patch adds those barrier functions and factors out
block_revalidate() and unblock_revalidate() far clarity.
There is also a hypothetical bug in that if memory allocation fails
(which never happens in practice) we might leave ->d_fsdata locked.
This patch adds the missing call to unblock_revalidate().
Reported-and-tested-by: Richard Kojedzinszky <richard+debian+bugreport@kojedz.in>
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1071501
Fixes: 3c59366c20 ("NFS: don't unhash dentry during unlink/rename")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28568c906c ]
In commit 4ca9f31a2b ("NFSv4.1 test and add 4.1 trunking transport"),
we introduce the ability to query the NFS server for possible trunking
locations of the existing filesystem. However, we never checked the
returned file system path for these alternative locations. According
to the RFC, the server can say that the filesystem currently known
under "fs_root" of fs_location also resides under these server
locations under the following "rootpath" pathname. The client cannot
handle trunking a filesystem that reside under different location
under different paths other than what the main path is. This patch
enforces the check that fs_root path and rootpath path in fs_location
reply is the same.
Fixes: 4ca9f31a2b ("NFSv4.1 test and add 4.1 trunking transport")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f06d1b10cb upstream.
Olga showed me a case where the client was sending multiple READ_PLUS
calls to the server in parallel, and the server replied
NFS4ERR_OPNOTSUPP to each. The client would fall back to READ for the
first reply, but fail to retry the other calls.
I fix this by removing the test for NFS_CAP_READ_PLUS in
nfs4_read_plus_not_supported(). This allows us to reschedule any
READ_PLUS call that has a NFS4ERR_OPNOTSUPP return value, even after the
capability has been cleared.
Reported-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: c567552612 ("NFS: Add READ_PLUS data segment support")
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3c0a2e0b0a upstream.
Shifting *signed int* typed constant 1 left by 31 bits causes undefined
behavior. Specify the correct *unsigned long* type by using 1UL instead.
Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.
Cc: stable@vger.kernel.org
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b322bf9e98 ]
With newer kernels that use fs_context for nfs mounts, remounts fail with
-EINVAL.
$ mount -t nfs -o nolock 10.0.0.1:/tmp/test /mnt/test/
$ mount -t nfs -o remount /mnt/test/
mount: mounting 10.0.0.1:/tmp/test on /mnt/test failed: Invalid argument
For remounts, the nfs server address and port are populated by
nfs_init_fs_context and later overwritten with 0x00 bytes by
nfs23_parse_monolithic. The remount then fails as the server address is
invalid.
Fix this by not overwriting nfs server info in nfs23_parse_monolithic if
we're doing a remount.
Fixes: f2aedb713c ("NFS: Add fs_context support.")
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 37ffe06537 ]
Dan Carpenter reports smatch warning for nfs4_try_migration() when a memory
allocation failure results in a zero return value. In this case, a
transient allocation failure error will likely be retried the next time the
server responds with NFS4ERR_MOVED.
We can fixup the smatch warning with a small refactor: attempt all three
allocations before testing and returning on a failure.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: c3ed222745 ("NFSv4: Fix free of uninitialized nfs4_label on referral lookup.")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3903902401 upstream.
The original implementation of nfsd used signals to stop threads during
shutdown.
In Linux 2.3.46pre5 nfsd gained the ability to shutdown threads
internally it if was asked to run "0" threads. After this user-space
transitioned to using "rpc.nfsd 0" to stop nfsd and sending signals to
threads was no longer an important part of the API.
In commit 3ebdbe5203 ("SUNRPC: discard svo_setup and rename
svc_set_num_threads_sync()") (v5.17-rc1~75^2~41) we finally removed the
use of signals for stopping threads, using kthread_stop() instead.
This patch makes the "obvious" next step and removes the ability to
signal nfsd threads - or any svc threads. nfsd stops allowing signals
and we don't check for their delivery any more.
This will allow for some simplification in later patches.
A change worth noting is in nfsd4_ssc_setup_dul(). There was previously
a signal_pending() check which would only succeed when the thread was
being shut down. It should really have tested kthread_should_stop() as
well. Now it just does the latter, not the former.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1548036ef1 ]
Now that we're exposing the rpc stats on a per-network namespace basis,
move this struct into struct nfs_net and use that to make sure only the
per-network namespace stats are exposed.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Stable-dep-of: 24457f1be2 ("nfs: Handle error of rpc_proc_register() in nfs_net_init().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d47151b79e ]
We're using nfs mounts inside of containers in production and noticed
that the nfs stats are not exposed in /proc. This is a problem for us
as we use these stats for monitoring, and have to do this awkward bind
mount from the main host into the container in order to get to these
states.
Add the rpc_proc_register call to the pernet operations entry and exit
points so these stats can be exposed inside of network namespaces.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Stable-dep-of: 24457f1be2 ("nfs: Handle error of rpc_proc_register() in nfs_net_init().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 17f46b803d ]
In production we have been hitting the following warning consistently
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 17 PID: 1800359 at lib/refcount.c:28 refcount_warn_saturate+0x9c/0xe0
Workqueue: nfsiod nfs_direct_write_schedule_work [nfs]
RIP: 0010:refcount_warn_saturate+0x9c/0xe0
PKRU: 55555554
Call Trace:
<TASK>
? __warn+0x9f/0x130
? refcount_warn_saturate+0x9c/0xe0
? report_bug+0xcc/0x150
? handle_bug+0x3d/0x70
? exc_invalid_op+0x16/0x40
? asm_exc_invalid_op+0x16/0x20
? refcount_warn_saturate+0x9c/0xe0
nfs_direct_write_schedule_work+0x237/0x250 [nfs]
process_one_work+0x12f/0x4a0
worker_thread+0x14e/0x3b0
? ZSTD_getCParams_internal+0x220/0x220
kthread+0xdc/0x120
? __btf_name_valid+0xa0/0xa0
ret_from_fork+0x1f/0x30
This is because we're completing the nfs_direct_request twice in a row.
The source of this is when we have our commit requests to submit, we
process them and send them off, and then in the completion path for the
commit requests we have
if (nfs_commit_end(cinfo.mds))
nfs_direct_write_complete(dreq);
However since we're submitting asynchronous requests we sometimes have
one that completes before we submit the next one, so we end up calling
complete on the nfs_direct_request twice.
The only other place we use nfs_generic_commit_list() is in
__nfs_commit_inode, which wraps this call in a
nfs_commit_begin();
nfs_commit_end();
Which is a common pattern for this style of completion handling, one
that is also repeated in the direct code with get_dreq()/put_dreq()
calls around where we process events as well as in the completion paths.
Fix this by using the same pattern for the commit requests.
Before with my 200 node rocksdb stress running this warning would pop
every 10ish minutes. With my patch the stress test has been running for
several hours without popping.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 719fcafe07 ]
We've been seeing the following panic in production
BUG: kernel NULL pointer dereference, address: 0000000000000065
PGD 2f485f067 P4D 2f485f067 PUD 2cc5d8067 PMD 0
RIP: 0010:ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
Call Trace:
<TASK>
? __die+0x78/0xc0
? page_fault_oops+0x286/0x380
? __rpc_execute+0x2c3/0x470 [sunrpc]
? rpc_new_task+0x42/0x1c0 [sunrpc]
? exc_page_fault+0x5d/0x110
? asm_exc_page_fault+0x22/0x30
? ff_layout_free_layoutreturn+0x110/0x110 [nfs_layout_flexfiles]
? ff_layout_cancel_io+0x3a/0x90 [nfs_layout_flexfiles]
? ff_layout_cancel_io+0x6f/0x90 [nfs_layout_flexfiles]
pnfs_mark_matching_lsegs_return+0x1b0/0x360 [nfsv4]
pnfs_error_mark_layout_for_return+0x9e/0x110 [nfsv4]
? ff_layout_send_layouterror+0x50/0x160 [nfs_layout_flexfiles]
nfs4_ff_layout_prepare_ds+0x11f/0x290 [nfs_layout_flexfiles]
ff_layout_pg_init_write+0xf0/0x1f0 [nfs_layout_flexfiles]
__nfs_pageio_add_request+0x154/0x6c0 [nfs]
nfs_pageio_add_request+0x26b/0x380 [nfs]
nfs_do_writepage+0x111/0x1e0 [nfs]
nfs_writepages_callback+0xf/0x30 [nfs]
write_cache_pages+0x17f/0x380
? nfs_pageio_init_write+0x50/0x50 [nfs]
? nfs_writepages+0x6d/0x210 [nfs]
? nfs_writepages+0x6d/0x210 [nfs]
nfs_writepages+0x125/0x210 [nfs]
do_writepages+0x67/0x220
? generic_perform_write+0x14b/0x210
filemap_fdatawrite_wbc+0x5b/0x80
file_write_and_wait_range+0x6d/0xc0
nfs_file_fsync+0x81/0x170 [nfs]
? nfs_file_mmap+0x60/0x60 [nfs]
__x64_sys_fsync+0x53/0x90
do_syscall_64+0x3d/0x90
entry_SYSCALL_64_after_hwframe+0x46/0xb0
Inspecting the core with drgn I was able to pull this
>>> prog.crashed_thread().stack_trace()[0]
#0 at 0xffffffffa079657a (ff_layout_cancel_io+0x3a/0x84) in ff_layout_cancel_io at fs/nfs/flexfilelayout/flexfilelayout.c:2021:27
>>> prog.crashed_thread().stack_trace()[0]['idx']
(u32)1
>>> prog.crashed_thread().stack_trace()[0]['flseg'].mirror_array[1].mirror_ds
(struct nfs4_ff_layout_ds *)0xffffffffffffffed
This is clear from the stack trace, we call nfs4_ff_layout_prepare_ds()
which could error out initializing the mirror_ds, and then we go to
clean it all up and our check is only for if (!mirror->mirror_ds). This
is inconsistent with the rest of the users of mirror_ds, which have
if (IS_ERR_OR_NULL(mirror_ds))
to keep from tripping over this exact scenario. Fix this up in
ff_layout_cancel_io() to make sure we don't panic when we get an error.
I also spot checked all the other instances of checking mirror_ds and we
appear to be doing the correct checks everywhere, only unconditionally
dereferencing mirror_ds when we know it would be valid.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Fixes: b739a5bd9d ("NFSv4/flexfiles: Cancel I/O if the layout is recalled or revoked")
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 698ad1a538 ]
The intent is to check if 'dest' is truncated or not. So, >= should be
used instead of >, because strlcat() returns the length of 'dest' and 'src'
excluding the trailing NULL.
Fixes: 56463e50d1 ("NFS: Use super.c for NFSROOT mount option parsing")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bcac8bff90 ]
Switch order of operations to avoid creating a short XDR buffer:
e.g., buflen = 12, old xdrlen = 12, new xdrlen = 20.
Having a short XDR buffer leads to lxa_maxcount be a few bytes
less than what is needed to retrieve the whole list when using
a buflen as returned by a call with size = 0:
buflen = listxattr(path, NULL, 0);
buf = malloc(buflen);
buflen = listxattr(path, buf, buflen);
For a file with one attribute (name = '123456'), the first call
with size = 0 will return buflen = 12 ('user.123456\x00').
The second call with size = 12, sends LISTXATTRS with
lxa_maxcount = 12 + 8 (cookie) + 4 (array count) = 24. The
XDR buffer needs 8 (cookie) + 4 (array count) + 4 (name count)
+ 6 (name len) + 2 (padding) + 4 (eof) = 28 which is 4 bytes
shorter than the lxa_maxcount provided in the call.
Fixes: 04a5da690e ("NFSv4.2: define limits and sizes for user xattr handling")
Signed-off-by: Jorge Mora <mora@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 251a658bbf ]
A call to listxattr() with a buffer size = 0 returns the actual
size of the buffer needed for a subsequent call. When size > 0,
nfs4_listxattr() does not return an error because either
generic_listxattr() or nfs4_listxattr_nfs4_label() consumes
exactly all the bytes then size is 0 when calling
nfs4_listxattr_nfs4_user() which then triggers the following
kernel BUG:
[ 99.403778] kernel BUG at mm/usercopy.c:102!
[ 99.404063] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
[ 99.408463] CPU: 0 PID: 3310 Comm: python3 Not tainted 6.6.0-61.fc40.aarch64 #1
[ 99.415827] Call trace:
[ 99.415985] usercopy_abort+0x70/0xa0
[ 99.416227] __check_heap_object+0x134/0x158
[ 99.416505] check_heap_object+0x150/0x188
[ 99.416696] __check_object_size.part.0+0x78/0x168
[ 99.416886] __check_object_size+0x28/0x40
[ 99.417078] listxattr+0x8c/0x120
[ 99.417252] path_listxattr+0x78/0xe0
[ 99.417476] __arm64_sys_listxattr+0x28/0x40
[ 99.417723] invoke_syscall+0x78/0x100
[ 99.417929] el0_svc_common.constprop.0+0x48/0xf0
[ 99.418186] do_el0_svc+0x24/0x38
[ 99.418376] el0_svc+0x3c/0x110
[ 99.418554] el0t_64_sync_handler+0x120/0x130
[ 99.418788] el0t_64_sync+0x194/0x198
[ 99.418994] Code: aa0003e3 d000a3e0 91310000 97f49bdb (d4210000)
Issue is reproduced when generic_listxattr() returns 'system.nfs4_acl',
thus calling lisxattr() with size = 16 will trigger the bug.
Add check on nfs4_listxattr() to return ERANGE error when it is
called with size > 0 and the return value is greater than size.
Fixes: 012a211abd ("NFSv4.2: hook in the user extended attribute handlers")
Signed-off-by: Jorge Mora <mora@netapp.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dcb779fcd4 ]
On most filesystems, there is no reason to delay reaping an nfsd_file
just because its underlying inode is still under writeback. nfsd just
relies on client activity or the local flusher threads to do writeback.
The main exception is NFS, which flushes all of its dirty data on last
close. Add a new EXPORT_OP_FLUSH_ON_CLOSE flag to allow filesystems to
signal that they do this, and only skip closing files under writeback on
such filesystems.
Also, remove a redundant NULL file pointer check in
nfsd_file_check_writeback, and clean up nfs's export op flag
definitions.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
[ cel: adjusted to apply to v6.1.y ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 247c01ff5f ]
Steven Rostedt says:
> The include/trace/events/ directory should only hold files that
> are to create events, not headers that hold helper functions.
>
> Can you please move them out of include/trace/events/ as that
> directory is "special" in the creation of events.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Stable-dep-of: 638593be55 ("NFSD: add CB_RECALL_ANY tracepoints")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
when AOP_WRITEPAGE_ACTIVATE is returned (as NFS does when it detects
congestion) it is important that the page is redirtied.
nfs_writepage_locked() doesn't do this, so files can become corrupted as
writes can be lost.
Note that this is not needed in v6.8 as AOP_WRITEPAGE_ACTIVATE cannot be
returned. It is needed for kernels v5.18..v6.7. From 6.3 onward the patch
is different as it needs to mention "folio", not "page".
Reported-and-tested-by: Jacek Tomaka <Jacek.Tomaka@poczta.fm>
Fixes: 6df25e5853 ("nfs: remove reliance on bdi congestion")
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8a6291bf3b ]
Instead of relying on the value of the 'bytes_left' field, we should
calculate the layout size based on the offset of the request that is
being written out.
Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fixes: 954998b60c ("NFS: Fix error handling for O_DIRECT write scheduling")
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 037e56a22f ]
Once the client has processed the CB_LAYOUTRECALL, but has not yet
successfully returned the layout, the server is supposed to switch to
returning NFS4ERR_RETURNCONFLICT. This patch ensures that we handle
that return value correctly.
Fixes: 183d9e7b11 ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1530827b90 ]
The error path for blocklayout's device lookup is missing a reference drop
for the case where a lookup finds the device, but the device is marked with
NFS_DEVICEID_UNAVAILABLE.
Fixes: b3dce6a2f0 ("pnfs/blocklayout: handle transient devices")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b4fa966f03 ]
Fscache has an optimisation by which reads from the cache are skipped
until we know that (a) there's data there to be read and (b) that data
isn't entirely covered by pages resident in the netfs pagecache. This is
done with two flags manipulated by fscache_note_page_release():
if (...
test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) &&
test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags))
clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags);
where the NO_DATA_TO_READ flag causes cachefiles_prepare_read() to
indicate that netfslib should download from the server or clear the page
instead.
The fscache_note_page_release() function is intended to be called from
->releasepage() - but that only gets called if PG_private or PG_private_2
is set - and currently the former is at the discretion of the network
filesystem and the latter is only set whilst a page is being written to
the cache, so sometimes we miss clearing the optimisation.
Fix this by following Willy's suggestion[1] and adding an address_space
flag, AS_RELEASE_ALWAYS, that causes filemap_release_folio() to always call
->release_folio() if it's set, even if PG_private or PG_private_2 aren't
set.
Note that this would require folio_test_private() and page_has_private() to
become more complicated. To avoid that, in the places[*] where these are
used to conditionalise calls to filemap_release_folio() and
try_to_release_page(), the tests are removed the those functions just
jumped to unconditionally and the test is performed there.
[*] There are some exceptions in vmscan.c where the check guards more than
just a call to the releaser. I've added a function, folio_needs_release()
to wrap all the checks for that.
AS_RELEASE_ALWAYS should be set if a non-NULL cookie is obtained from
fscache and cleared in ->evict_inode() before truncate_inode_pages_final()
is called.
Additionally, the FSCACHE_COOKIE_NO_DATA_TO_READ flag needs to be cleared
and the optimisation cancelled if a cachefiles object already contains data
when we open it.
[dwysocha@redhat.com: call folio_mapping() inside folio_needs_release()]
Link: 902c990e31
Link: https://lkml.kernel.org/r/20230628104852.3391651-3-dhowells@redhat.com
Fixes: 1f67e6d0b1 ("fscache: Provide a function to note the release of a page")
Fixes: 047487c947 ("cachefiles: Implement the I/O routines")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Reported-by: Rohith Surabattula <rohiths.msft@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: SeongJae Park <sj@kernel.org>
Cc: Daire Byrne <daire.byrne@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steve French <sfrench@samba.org>
Cc: Shyam Prasad N <nspmangalore@gmail.com>
Cc: Rohith Surabattula <rohiths.msft@gmail.com>
Cc: Dave Wysochanski <dwysocha@redhat.com>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 1898efcdbe ("block: update the stable_writes flag in bdev_add")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5cc7688bae ]
If the client is doing pnfs IO and Kerberos is configured and EXCHANGEID
successfully negotiated SP4_MACH_CRED and WRITE/COMMIT are on the
list of state protected operations, then we need to make sure to
choose the DS's rpc_client structure instead of the MDS's one.
Fixes: fb91fb0ee7 ("NFS: Move call to nfs4_state_protect_write() to nfs4_write_setup()")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6bd1a77dc7 ]
Currently when client sends an EXCHANGE_ID for a possible trunked
connection, for any error that happened, the trunk will be thrown
out. However, an NFS4ERR_DELAY is a transient error that should be
retried instead.
Fixes: e818bd085b ("NFSv4.1 remove xprt from xprt_switch if session trunking test fails")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f588d72bd9 upstream.
The Linux NFS server strips the SUID and SGID from the file mode
on ALLOCATE op.
Modify _nfs42_proc_fallocate to add NFS_INO_REVAL_FORCED to
nfs_set_cache_invalid's argument to force update of the file
mode suid/sgid bit.
Suggested-by: Trond Myklebust <trondmy@hammerspace.com>
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 379e4adfdd upstream.
This patches fixes commit 51d674a5e4 "NFSv4.1: use
EXCHGID4_FLAG_USE_PNFS_DS for DS server", purpose of that
commit was to mark EXCHANGE_ID to the DS with the appropriate
flag.
However, connection to MDS can return both EXCHGID4_FLAG_USE_PNFS_DS
and EXCHGID4_FLAG_USE_PNFS_MDS set but previous patch would only
remember the USE_PNFS_DS and for the 2nd EXCHANGE_ID send that
to the MDS.
Instead, just mark the pnfs path exclusively.
Fixes: 51d674a5e4 ("NFSv4.1: use EXCHGID4_FLAG_USE_PNFS_DS for DS server")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e1c6cfbb3b upstream.
Ensure that we check the layout pointer and validity after dereferencing
it in ff_layout_mirror_prepare_stats.
Fixes: 08e2e5bc6c ("pNFS/flexfiles: Clean up layoutstats")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f63955721a upstream.
We are not allowed to call pnfs_mark_matching_lsegs_return() without
also holding a reference to the layout header, since doing so could lead
to the reference count going to zero when we call
pnfs_layout_remove_lseg(). This again can lead to a hang when we get to
nfs4_evict_inode() and are unable to clear the layout pointer.
pnfs_layout_return_unused_byserver() is guilty of this behaviour, and
has been seen to trigger the refcount warning prior to a hang.
Fixes: b6d49ecd10 ("NFSv4: Fix a pNFS layout related use-after-free race when freeing the inode")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
