Commit Graph

518 Commits

Author SHA1 Message Date
Trond Myklebust
9fcd5960e8 NFS: Add a helper to return a pointer to the open context of a struct nfs_page
Add a helper for when we remove the explicit pointer to the open
context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:15 -04:00
Trond Myklebust
33344e0f7e pNFS: Add tracking to limit the number of pNFS retries
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
28b1d3f5a7 NFS: Remove unused argument from nfs_create_request()
All the callers of nfs_create_request() are now creating page group
heads, so we can remove the redundant 'last' page argument.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
6fbda89b25 NFS: Replace custom error reporting mechanism with generic one
Replace the NFS custom error reporting mechanism with the generic
mapping_set_error().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
22876f540b NFS: Don't call generic_error_remove_page() while holding locks
The NFS read code can trigger writeback while holding the page lock.
If an error then triggers a call to nfs_write_error_remove_page(),
we can deadlock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
14bebe3c90 NFS: Don't interrupt file writeout due to fatal errors
When flushing out dirty pages, the fact that we may hit fatal errors
is not a reason to stop writeback. Those errors are reported through
fsync(), not through the flush mechanism.

Fixes: a6598813a4 ("NFS: Don't write back further requests if there...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
302fad7bd5 NFS: Fix up documentation warnings
Fix up some compiler warnings about function parameters, etc not being
correctly described or formatted.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 15:14:21 -05:00
Trond Myklebust
875bc3fbf2 NFS: Ensure NFS writeback allocations don't recurse back into NFS.
All the allocations that we can hit in the NFS layer and sunrpc layers
themselves are already marked as GFP_NOFS, but we need to ensure that
any calls to generic kernel functionality do the right thing as well.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 15:14:20 -05:00
Trond Myklebust
df3accb849 NFS: Pass error information to the pgio error cleanup routine
Allow the caller to pass error information when cleaning up a failed
I/O request so that we can conditionally take action to cancel the
request altogether if the error turned out to be fatal.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-02-20 15:14:20 -05:00
Benjamin Coddington
d2ceb7e570 NFS: Don't use page_file_mapping after removing the page
If nfs_page_async_flush() removes the page from the mapping, then we can't
use page_file_mapping() on it as nfs_updatepate() is wont to do when
receiving an error.  Instead, push the mapping to the stack before the page
is possibly truncated.

Fixes: 8fc75bed96 ("NFS: Fix up return value on fatal errors in nfs_page_async_flush()")
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-02-12 15:56:28 -05:00
Trond Myklebust
8fc75bed96 NFS: Fix up return value on fatal errors in nfs_page_async_flush()
Ensure that we return the fatal error value that caused us to exit
nfs_page_async_flush().

Fixes: c373fff7bd ("NFSv4: Don't special case "launder"")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.12+
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-01-29 16:33:24 -05:00
Linus Torvalds
e6b9257280 NFS client updates for Linux 4.21
Note that there is a conflict with the rdma tree in this pull request, since
 we delete a file that has been changed in the rdma tree.  Hopefully that's
 easy enough to resolve!
 
 We also were unable to track down a maintainer for Neil Brown's changes to
 the generic cred code that are prerequisites to his RPC cred cleanup patches.
 We've been asking around for several months without any response, so
 hopefully it's okay to include those patches in this pull request.
 
 Stable bugfixes:
 - xprtrdma: Yet another double DMA-unmap # v4.20
 
 Features:
 - Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG
 - Per-xprt rdma receive workqueues
 - Drop support for FMR memory registration
 - Make port= mount option optional for RDMA mounts
 
 Other bugfixes and cleanups:
 - Remove unused nfs4_xdev_fs_type declaration
 - Fix comments for behavior that has changed
 - Remove generic RPC credentials by switching to 'struct cred'
 - Fix crossing mountpoints with different auth flavors
 - Various xprtrdma fixes from testing and auditing the close code
 - Fixes for disconnect issues when using xprtrdma with krb5
 - Clean up and improve xprtrdma trace points
 - Fix NFS v4.2 async copy reboot recovery
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlwtO50ACgkQ18tUv7Cl
 QOtZWQ//e5Hhp2TnQZ6U+99YKedjwBHP6psH3GKSEdeHSNdlSpZ5ckgHxvMb9TBa
 6t4ecgv5P/uYLIePQ0u2ubUFc9+TlyGi7Iacx13/YhK7kihGHDPnZhfl0QbYixV7
 rwa9bFcKmOrXs8ld+Hw3P2UL22G1gMf/LHDhPNshbW7LFZmcshKz+mKTk70kwkq9
 v7tFC59p6GwV8Sr2YI2NXn2fOWsUS00sQfgj2jceJYJ8PsNa+wHYF4wPj2IY5NsE
 D5Oq2kLPbytBhCllOHgopNZaf4qb5BfqhVETyc1O+kDF3BZKUhQ1PoDi2FPinaHM
 5/d8hS+5fr3eMBsQrPWQLXYjWQFUXnkQQJvU3Bo52AIgomsk/8uBq3FvH7XmFcBd
 C8sgnuUAkAS8feMes8GCS50BTxclnGuYGdyFJyCRXoG9Kn9rMrw9EKitky6EVq0v
 NmXhW79jK84a3yDXVlAIpZ8Y9BU/HQ3GviGX8lQEdZU9YiYRzDIHvpMFwzMgqaBi
 XvLbr8PlLOm8GZokThS8QYT/G2Wu6IwfUq/AufVjVD4+HiL3duKKfWSGAvcm6aAa
 GoRF6UG+OmjWlzKojtRc1dI+sy22Fzh+DW+Mx6tuf/b/66wkmYnW7eKcV4rt6Tm5
 /JEhvTMo9q7elL/4FgCoMCcdoc5eXqQyXRXrQiOU7YHLzn2aWU0=
 =DvVW
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - xprtrdma: Yet another double DMA-unmap # v4.20

  Features:
   - Allow some /proc/sys/sunrpc entries without CONFIG_SUNRPC_DEBUG
   - Per-xprt rdma receive workqueues
   - Drop support for FMR memory registration
   - Make port= mount option optional for RDMA mounts

  Other bugfixes and cleanups:
   - Remove unused nfs4_xdev_fs_type declaration
   - Fix comments for behavior that has changed
   - Remove generic RPC credentials by switching to 'struct cred'
   - Fix crossing mountpoints with different auth flavors
   - Various xprtrdma fixes from testing and auditing the close code
   - Fixes for disconnect issues when using xprtrdma with krb5
   - Clean up and improve xprtrdma trace points
   - Fix NFS v4.2 async copy reboot recovery"

* tag 'nfs-for-4.21-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (63 commits)
  sunrpc: convert to DEFINE_SHOW_ATTRIBUTE
  sunrpc: Add xprt after nfs4_test_session_trunk()
  sunrpc: convert unnecessary GFP_ATOMIC to GFP_NOFS
  sunrpc: handle ENOMEM in rpcb_getport_async
  NFS: remove unnecessary test for IS_ERR(cred)
  xprtrdma: Prevent leak of rpcrdma_rep objects
  NFSv4.2 fix async copy reboot recovery
  xprtrdma: Don't leak freed MRs
  xprtrdma: Add documenting comment for rpcrdma_buffer_destroy
  xprtrdma: Replace outdated comment for rpcrdma_ep_post
  xprtrdma: Update comments in frwr_op_send
  SUNRPC: Fix some kernel doc complaints
  SUNRPC: Simplify defining common RPC trace events
  NFS: Fix NFSv4 symbolic trace point output
  xprtrdma: Trace mapping, alloc, and dereg failures
  xprtrdma: Add trace points for calls to transport switch methods
  xprtrdma: Relocate the xprtrdma_mr_map trace points
  xprtrdma: Clean up of xprtrdma chunk trace points
  xprtrdma: Remove unused fields from rpcrdma_ia
  xprtrdma: Cull dprintk() call sites
  ...
2019-01-02 16:35:23 -08:00
Arun KS
ca79b0c211 mm: convert totalram_pages and totalhigh_pages variables to atomic
totalram_pages and totalhigh_pages are made static inline function.

Main motivation was that managed_page_count_lock handling was complicating
things.  It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.

[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS <arunks@codeaurora.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:47 -08:00
NeilBrown
a52458b48a NFS/NFSD/SUNRPC: replace generic creds with 'struct cred'.
SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.

Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:46 -05:00
NeilBrown
ddf529eeed NFS: move credential expiry tracking out of SUNRPC into NFS.
NFS needs to know when a credential is about to expire so that
it can modify write-back behaviour to finish the write inside the
expiry time.
It currently uses functions in SUNRPC code which make use of a
fairly complex callback scheme and flags in the generic credientials.

As I am working to discard the generic credentials, this has to change.

This patch moves the logic into NFS, in part by finding and caching
the low-level credential in the open_context.  We then make direct
cred-api calls on that.

This makes the code much simpler and removes a dependency on generic
rpc credentials.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-12-19 13:52:45 -05:00
Trond Myklebust
7be7b3ca16 NFS: Ensure we immediately start writeback on rescheduled writes
If the writes are being rescheduled due to a pNFS error, then we really
want to immediately start a new flush. The O_DIRECT code already does
this, so we only need to worry about buffered writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-07-26 16:25:25 -04:00
Anna Schumaker
e9ae1ee2b2 NFS: Move call to nfs4_state_protect() to nfs4_commit_setup()
Rather than doing this in the generic NFS client code.  Let's put this
with the other v4 stuff so it's all in one place.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-05-31 15:02:16 -04:00
Anna Schumaker
fb91fb0ee7 NFS: Move call to nfs4_state_protect_write() to nfs4_write_setup()
This doesn't really need to be in the generic NFS client code, and I
think it makes more sense to keep the v4 code in one place.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2018-05-31 15:02:16 -04:00
Linus Torvalds
a1bf4c7da6 NFS client updates for Linux 4.17
Stable bugfixes:
 - xprtrdma: Fix corner cases when handling device removal # v4.12+
 - xprtrdma: Fix latency regression on NUMA NFS/RDMA clients # v4.15+
 
 Features:
 - New sunrpc tracepoint for RPC pings
 - Finer grained NFSv4 attribute checking
 - Don't unnecessarily return NFS v4 delegations
 
 Other bugfixes and cleanups:
 - Several other small NFSoRDMA cleanups
 - Improvements to the sunrpc RTT measurements
 - A few sunrpc tracepoint cleanups
 - Various fixes for NFS v4 lock notifications
 - Various sunrpc and NFS v4 XDR encoding cleanups
 - Switch to the ida_simple API
 - Fix NFSv4.1 exclusive create
 - Forget acl cache after setattr operation
 - Don't advance the nfs_entry readdir cookie if xdr decoding fails
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEEnZ5MQTpR7cLU7KEp18tUv7ClQOsFAlrNG1IACgkQ18tUv7Cl
 QOvotw//fQoUgQ/AOJGlZo/4ws2mGJN3dfwwKM8xYOnHaxppOYubZRHwvswK8d22
 +XR/Q6IVbUxI3mJluv1L0d9CJT06s3c9CO90McIJbk4CWihGP19bNIY4JiPlzrbv
 4FDiyOvMBej2UXbHX5EzKj0srxyBoEVf3iUAIa6DaHi3c6EIUo6fP3d2eRNJStqd
 WMyZs+nqr2W9biyClxntT7l/Sk+o+4I7M3Oo9pjjS+PiePYdaMrL5T1kPeHaJshF
 GMGXkbvVdqpDRiXX84R9+2/nuSiA15eEnaR94UNvs84oLR3qob3ZhxhudqFdSPrX
 RS6E7m34gY/EaQm/wbB26PZm+3jHd4Pqm5SKLbyFfoCmG6oMwBvXNRJZas1DFaHM
 CMOECvfAr6kixVLkAN0MNQ2Ku/FuJ52OLP1dRLmxsblocnhEPujc6RSz6Ju/v3a0
 adbpmJMA2IoSGgXMu3g1VGnjHfMj7ZmjtpigXVvlcUqQGCL7t4ngh23cpeTQeJ76
 bMwSHUQu18NbmtJjBTE+PIm7mdCrpQD7ZuOPWpK62zxLYUnnv7nm75m84DrDru7d
 XAmrCmdUJNrVWQs6BAtCXgO4PZ6xNGLosb0xTQXTAQYftc+DRJ9SW/VGc0Mp1L9m
 0G0iz++b8cy4Pih5UCDJcCkpjCIvHLcn72zn1kbufWqG3xr2koc=
 =IlWo
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

Pull NFS client updates from Anna Schumaker:
 "Stable bugfixes:
   - xprtrdma: Fix corner cases when handling device removal # v4.12+
   - xprtrdma: Fix latency regression on NUMA NFS/RDMA clients # v4.15+

  Features:
   - New sunrpc tracepoint for RPC pings
   - Finer grained NFSv4 attribute checking
   - Don't unnecessarily return NFS v4 delegations

  Other bugfixes and cleanups:
   - Several other small NFSoRDMA cleanups
   - Improvements to the sunrpc RTT measurements
   - A few sunrpc tracepoint cleanups
   - Various fixes for NFS v4 lock notifications
   - Various sunrpc and NFS v4 XDR encoding cleanups
   - Switch to the ida_simple API
   - Fix NFSv4.1 exclusive create
   - Forget acl cache after setattr operation
   - Don't advance the nfs_entry readdir cookie if xdr decoding fails"

* tag 'nfs-for-4.17-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (47 commits)
  NFS: advance nfs_entry cookie only after decoding completes successfully
  NFSv3/acl: forget acl cache after setattr
  NFSv4.1: Fix exclusive create
  NFSv4: Declare the size up to date after it was set.
  nfs: Use ida_simple API
  NFSv4: Fix the nfs_inode_set_delegation() arguments
  NFSv4: Clean up CB_GETATTR encoding
  NFSv4: Don't ask for attributes when ACCESS is protected by a delegation
  NFSv4: Add a helper to encode/decode struct timespec
  NFSv4: Clean up encode_attrs
  NFSv4; Clean up XDR encoding of type bitmap4
  NFSv4: Allow GFP_NOIO sleeps in decode_attr_owner/decode_attr_group
  SUNRPC: Add a helper for encoding opaque data inline
  SUNRPC: Add helpers for decoding opaque and string types
  NFSv4: Ignore change attribute invalidations if we hold a delegation
  NFS: More fine grained attribute tracking
  NFS: Don't force unnecessary cache invalidation in nfs_update_inode()
  NFS: Don't redirty the attribute cache in nfs_wcc_update_inode()
  NFS: Don't force a revalidation of all attributes if change is missing
  NFS: Convert NFS_INO_INVALID flags to unsigned long
  ...
2018-04-12 12:55:50 -07:00
Trond Myklebust
f6cdfa6dd6 NFSv4: Declare the size up to date after it was set.
When we've changed the file size, then ensure we declare it to be
up to date in the inode attributes.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Trond Myklebust
16e1437517 NFS: More fine grained attribute tracking
Currently, if the NFS_INO_INVALID_ATTR flag is set, for instance by
a call to nfs_post_op_update_inode_locked(), then it will not be cleared
until all the attributes have been revalidated. This means, for instance,
that NFSv4 writes will always force a full attribute revalidation.

Track the ctime, mtime, size and change attribute separately from the
other attributes so that we can have nfs_post_op_update_inode_locked()
set them correctly, and later have the cache consistency bitmask be
able to clear them.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2018-04-10 16:06:22 -04:00
Linus Torvalds
ce6eba3dba Merge branch 'sched-wait-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull wait_var_event updates from Ingo Molnar:
 "This introduces the new wait_var_event() API, which is a more flexible
  waiting primitive than wait_on_atomic_t().

  All wait_on_atomic_t() users are migrated over to the new API and
  wait_on_atomic_t() is removed. The migration fixes one bug and should
  result in no functional changes for the other usecases"

* 'sched-wait-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/wait: Improve __var_waitqueue() code generation
  sched/wait: Remove the wait_on_atomic_t() API
  sched/wait, arch/mips: Fix and convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/ocfs2: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/fscache: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/btrfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, fs/afs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, drivers/media: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait, drivers/drm: Convert wait_on_atomic_t() usage to the new wait_var_event() API
  sched/wait: Introduce wait_var_event()
2018-04-02 16:50:39 -07:00
Peter Zijlstra
723c921e7d sched/wait, fs/nfs: Convert wait_on_atomic_t() usage to the new wait_var_event() API
The old wait_on_atomic_t() is going to get removed, use the more
flexible wait_var_event() API instead.

No change in functionality.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: Linus 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: Ingo Molnar <mingo@kernel.org>
2018-03-20 08:23:21 +01:00
Trond Myklebust
c4f24df942 NFS: Fix unstable write completion
We do want to respect the FLUSH_SYNC argument to nfs_commit_inode() to
ensure that all outstanding COMMIT requests to the inode in question are
complete. Currently we may exit early from both nfs_commit_inode() and
nfs_write_inode() even if there are COMMIT requests in flight, or unstable
writes on the commit list.

In order to get the right semantics w.r.t. sync_inode(), we don't need
to have nfs_commit_inode() reset the inode dirty flags when called from
nfs_wb_page() and/or nfs_wb_all(). We just need to ensure that
nfs_write_inode() leaves them in the right state if there are outstanding
commits, or stable pages.

Reported-by: Scott Mayhew <smayhew@redhat.com>
Fixes: dc4fd9ab01 ("nfs: don't wait on commit in nfs_commit_inode()...")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-03-08 12:56:32 -05:00
Linus Torvalds
efd52b5d36 NFS client updates for Linux 4.16
Highlights include:
 
 Stable bugfixes:
 - Fix breakages in the nfsstat utility due to the inclusion of the NFSv4
   LOOKUPP operation.
 - Fix a NULL pointer dereference in nfs_idmap_prepare_pipe_upcall() due to
   nfs_idmap_legacy_upcall() being called without an 'aux' parameter.
 - Fix a refcount leak in the standard O_DIRECT error path.
 - Fix a refcount leak in the pNFS O_DIRECT fallback to MDS path.
 - Fix CPU latency issues with nfs_commit_release_pages()
 - Fix the LAYOUTUNAVAILABLE error case in the file layout type.
 - NFS: Fix a race between mmap() and O_DIRECT
 
 Features:
 - Support the statx() mask and query flags to enable optimisations when
   the user is requesting only attributes that are already up to date in
   the inode cache, or is specifying the AT_STATX_DONT_SYNC flag.
 - Add a module alias for the SCSI pNFS layout type.
 
 Bugfixes:
 - Automounting when resolving a NFSv4 referral should preserve the RDMA
   transport protocol settings.
 - Various other RDMA bugfixes from Chuck.
 - pNFS block layout fixes.
 - Always set NFS_LOCK_LOST when a lock is lost.
 -----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJacHcyAAoJEGcL54qWCgDy5WcP/Aw7GIAVZ+n5B+EIFVvEaWlC
 C++eA8vej433ezKRj8IExeCX1C8OKrQZ4iQ3nqIg0mVVQS/Qk+469OhYP9jDagA+
 tDZeOs3lbl1EUhUWT+GNxw8bZqKGn9fYzcWFjiYeFTjrcfLYfZTW50V0tofjgmlR
 3nQmpPx/56rXE9ZO/EW66HRZWauw7a0hg3/5Ft+F5csqIb3yQOlW8Osp3WClzGBF
 to4lS8/IwHvCn3qWAMuivRaMJDxeKrmoJNQh9Kw1Mw3+vurGAjmKo1a153qKPz4N
 7wjeP+o3ujc/P7WsJLCIgQRimzSm9FZXMqEVmz07+cIhGbERt2yy0RbHev8bpa+U
 3IMj70K9ciPuMZwrAtRAeZL+o9gxlUGUXvTaDUgo4DFgBw9Q5CnMnFn6a725l4h0
 nSZsE+bR8d4l/yEjf77SbTrk7atMLfUG1XnKH20i1CUjtd4CaLLzjn81TlbQrfuI
 XaFdJUUt63dPTIbhPEk7wHFcITkGZiyXhcepgbaXLiDH/3gyZmqTYzJ2EH14sOC5
 NaTueE3ASTiFChvG7jvc89HJN5SN5W11PyzI+GHezx9VkFnPZM3/q2V7oEX2aSld
 tkRlDMO4dVmpAA4LVAAarDr0a8ZsJQOdb+yLn21pbmKNAs1vol7tMfJe57ykEV6v
 WNAgtKJLtZE0Lh1UyEq0
 =5Vv2
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable bugfixes:

   - Fix breakages in the nfsstat utility due to the inclusion of the
     NFSv4 LOOKUPP operation

   - Fix a NULL pointer dereference in nfs_idmap_prepare_pipe_upcall()
     due to nfs_idmap_legacy_upcall() being called without an 'aux'
     parameter

   - Fix a refcount leak in the standard O_DIRECT error path

   - Fix a refcount leak in the pNFS O_DIRECT fallback to MDS path

   - Fix CPU latency issues with nfs_commit_release_pages()

   - Fix the LAYOUTUNAVAILABLE error case in the file layout type

   - NFS: Fix a race between mmap() and O_DIRECT

  Features:

   - Support the statx() mask and query flags to enable optimisations
     when the user is requesting only attributes that are already up to
     date in the inode cache, or is specifying the AT_STATX_DONT_SYNC
     flag

   - Add a module alias for the SCSI pNFS layout type

  Bugfixes:

   - Automounting when resolving a NFSv4 referral should preserve the
     RDMA transport protocol settings

   - Various other RDMA bugfixes from Chuck

   - pNFS block layout fixes

   - Always set NFS_LOCK_LOST when a lock is lost"

* tag 'nfs-for-4.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (69 commits)
  NFS: Fix a race between mmap() and O_DIRECT
  NFS: Remove a redundant call to unmap_mapping_range()
  pnfs/blocklayout: Ensure disk address in block device map
  pnfs/blocklayout: pnfs_block_dev_map uses bytes, not sectors
  lockd: Fix server refcounting
  SUNRPC: Fix null rpc_clnt dereference in rpc_task_queued tracepoint
  SUNRPC: Micro-optimize __rpc_execute
  SUNRPC: task_run_action should display tk_callback
  sunrpc: Format RPC events consistently for display
  SUNRPC: Trace xprt_timer events
  xprtrdma: Correct some documenting comments
  xprtrdma: Fix "bytes registered" accounting
  xprtrdma: Instrument allocation/release of rpcrdma_req/rep objects
  xprtrdma: Add trace points to instrument QP and CQ access upcalls
  xprtrdma: Add trace points in the client-side backchannel code paths
  xprtrdma: Add trace points for connect events
  xprtrdma: Add trace points to instrument MR allocation and recovery
  xprtrdma: Add trace points to instrument memory invalidation
  xprtrdma: Add trace points in reply decoder path
  xprtrdma: Add trace points to instrument memory registration
  ..
2018-01-30 19:03:48 -08:00
Linus Torvalds
a4b7fd7d34 inode->i_version rework for v4.16
-----BEGIN PGP SIGNATURE-----
 
 iQIcBAABAgAGBQJabwjlAAoJEAAOaEEZVoIVeEEP/R84kZJjlZV/vNmFFvY46jM+
 0hpMHXRNym+nW1Du1CKNkesEUAY8ACAQIyzJh63Q72341QTDdz3+asHwPYRNOqdC
 PgryidPieojkNKQg+h7dmoKYlYh1xiCicvn66Q5PFb9B0lH36twekOK4X1qqJj8Z
 breRmRoFLka9looMSuYgwbErts023fmASalvGum6T0ZM/7F9hUj4O3OsQtKTLUNM
 VQ+gLJTQrUqrgzvWUwq3WTMa9YAaKP4oad8nsglNSpiVLG7WtURr5HokW9hAziqL
 k99Y+K2ni1wZJlNGJAyV7PyEG2ieI5Xn+LzM2RM+SndD1QHF2QXACmSTDYfL51k5
 G2RsKeTZvQPtX4qx9+vnCp/4oV6JduvCaq2Mt8SQb9nYZxKjs85TNLrARJv+85eQ
 zP0OTxlH1Gfu3j36n3cny4XemyMYYF4hCFYfRPqTGst37fgLBtfIfUSQ6jedoCK2
 Xcyb6ukGXMh6If/A7DSy91hvSSPrWSH7TPPsbfLy6o+wUOtpAGR4eXVlEuAiXrzc
 gnoAz85oIMUQae66LrdrPk1NyE59qOb24g/yU5gyRBSpi2+/aoboNCKaD73tgs/C
 XIMwGXLYmqkcud7IBQF0tHHiM+jsEkbSM4LUqRXSnqMdwNnS18Z4Q+JKqpdP0cii
 eRdenDvUfu8Gu1Y9vWBv
 =iihN
 -----END PGP SIGNATURE-----

Merge tag 'iversion-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull inode->i_version rework from Jeff Layton:
 "This pile of patches is a rework of the inode->i_version field. We
  have traditionally incremented that field on every inode data or
  metadata change. Typically this increment needs to be logged on disk
  even when nothing else has changed, which is rather expensive.

  It turns out though that none of the consumers of that field actually
  require this behavior. The only real requirement for all of them is
  that it be different iff the inode has changed since the last time the
  field was checked.

  Given that, we can optimize away most of the i_version increments and
  avoid dirtying inode metadata when the only change is to the i_version
  and no one is querying it. Queries of the i_version field are rather
  rare, so we can help write performance under many common workloads.

  This patch series converts existing accesses of the i_version field to
  a new API, and then converts all of the in-kernel filesystems to use
  it. The last patch in the series then converts the backend
  implementation to a scheme that optimizes away a large portion of the
  metadata updates when no one is looking at it.

  In my own testing this series significantly helps performance with
  small I/O sizes. I also got this email for Christmas this year from
  the kernel test robot (a 244% r/w bandwidth improvement with XFS over
  DAX, with 4k writes):

    https://lkml.org/lkml/2017/12/25/8

  A few of the earlier patches in this pile are also flowing to you via
  other trees (mm, integrity, and nfsd trees in particular)".

* tag 'iversion-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: (22 commits)
  fs: handle inode->i_version more efficiently
  btrfs: only dirty the inode in btrfs_update_time if something was changed
  xfs: avoid setting XFS_ILOG_CORE if i_version doesn't need incrementing
  fs: only set S_VERSION when updating times if necessary
  IMA: switch IMA over to new i_version API
  xfs: convert to new i_version API
  ufs: use new i_version API
  ocfs2: convert to new i_version API
  nfsd: convert to new i_version API
  nfs: convert to new i_version API
  ext4: convert to new i_version API
  ext2: convert to new i_version API
  exofs: switch to new i_version API
  btrfs: convert to new i_version API
  afs: convert to new i_version API
  affs: convert to new i_version API
  fat: convert to new i_version API
  fs: don't take the i_lock in inode_inc_iversion
  fs: new API for handling inode->i_version
  ntfs: remove i_version handling
  ...
2018-01-29 13:33:53 -08:00
Jeff Layton
1eb5d98f16 nfs: convert to new i_version API
For NFS, we just use the "raw" API since the i_version is mostly
managed by the server. The exception there is when the client
holds a write delegation, but we only need to bump it once
there anyway to handle CB_GETATTR.

Tested-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2018-01-29 06:42:21 -05:00
Trond Myklebust
7f1bda447c NFS: Add a cond_resched() to nfs_commit_release_pages()
The commit list can get very large, and so we need a cond_resched()
in nfs_commit_release_pages() in order to ensure we don't hog the CPU
for excessive periods of time.

Reported-by: Mike Galbraith <efault@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2018-01-14 23:06:28 -05:00
Scott Mayhew
dc4fd9ab01 nfs: don't wait on commit in nfs_commit_inode() if there were no commit requests
If there were no commit requests, then nfs_commit_inode() should not
wait on the commit or mark the inode dirty, otherwise the following
BUG_ON can be triggered:

[ 1917.130762] kernel BUG at fs/inode.c:578!
[ 1917.130766] Oops: Exception in kernel mode, sig: 5 [#1]
[ 1917.130768] SMP NR_CPUS=2048 NUMA pSeries
[ 1917.130772] Modules linked in: iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi blocklayoutdriver rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache sunrpc sg nx_crypto pseries_rng ip_tables xfs libcrc32c sd_mod crc_t10dif crct10dif_generic crct10dif_common ibmvscsi scsi_transport_srp ibmveth scsi_tgt dm_mirror dm_region_hash dm_log dm_mod
[ 1917.130805] CPU: 2 PID: 14923 Comm: umount.nfs4 Tainted: G               ------------ T 3.10.0-768.el7.ppc64 #1
[ 1917.130810] task: c0000005ecd88040 ti: c00000004cea0000 task.ti: c00000004cea0000
[ 1917.130813] NIP: c000000000354178 LR: c000000000354160 CTR: c00000000012db80
[ 1917.130816] REGS: c00000004cea3720 TRAP: 0700   Tainted: G               ------------ T  (3.10.0-768.el7.ppc64)
[ 1917.130820] MSR: 8000000100029032 <SF,EE,ME,IR,DR,RI>  CR: 22002822  XER: 20000000
[ 1917.130828] CFAR: c00000000011f594 SOFTE: 1
GPR00: c000000000354160 c00000004cea39a0 c0000000014c4700 c0000000018cc750
GPR04: 000000000000c750 80c0000000000000 0600000000000000 04eeb76bea749a03
GPR08: 0000000000000034 c0000000018cc758 0000000000000001 d000000005e619e8
GPR12: c00000000012db80 c000000007b31200 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR24: 0000000000000000 c000000000dfc3ec 0000000000000000 c0000005eefc02c0
GPR28: d0000000079dbd50 c0000005b94a02c0 c0000005b94a0250 c0000005b94a01c8
[ 1917.130867] NIP [c000000000354178] .evict+0x1c8/0x350
[ 1917.130871] LR [c000000000354160] .evict+0x1b0/0x350
[ 1917.130873] Call Trace:
[ 1917.130876] [c00000004cea39a0] [c000000000354160] .evict+0x1b0/0x350 (unreliable)
[ 1917.130880] [c00000004cea3a30] [c0000000003558cc] .evict_inodes+0x13c/0x270
[ 1917.130884] [c00000004cea3af0] [c000000000327d20] .kill_anon_super+0x70/0x1e0
[ 1917.130896] [c00000004cea3b80] [d000000005e43e30] .nfs_kill_super+0x20/0x60 [nfs]
[ 1917.130900] [c00000004cea3c00] [c000000000328a20] .deactivate_locked_super+0xa0/0x1b0
[ 1917.130903] [c00000004cea3c80] [c00000000035ba54] .cleanup_mnt+0xd4/0x180
[ 1917.130907] [c00000004cea3d10] [c000000000119034] .task_work_run+0x114/0x150
[ 1917.130912] [c00000004cea3db0] [c00000000001ba6c] .do_notify_resume+0xcc/0x100
[ 1917.130916] [c00000004cea3e30] [c00000000000a7b0] .ret_from_except_lite+0x5c/0x60
[ 1917.130919] Instruction dump:
[ 1917.130921] 7fc3f378 486734b5 60000000 387f00a0 38800003 4bdcb365 60000000 e95f00a0
[ 1917.130927] 694a0060 7d4a0074 794ad182 694a0001 <0b0a0000> 892d02a4 2f890000 40de0134

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org # 4.5+
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-12-15 14:31:50 -05:00
Markus Elfring
0671d8f108 nfs/write: Use common error handling code in nfs_lock_and_join_requests()
Add a jump target so that a bit of exception handling can be better reused
at the end of this function.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2017-11-17 16:43:50 -05:00
NeilBrown
bf4b490597 NFS: various changes relating to reporting IO errors.
1/ remove 'start' and 'end' args from nfs_file_fsync_commit().
   They aren't used.

2/ Make nfs_context_set_write_error() a "static inline" in internal.h
   so we can...

3/ Use nfs_context_set_write_error() instead of mapping_set_error()
   if nfs_pageio_add_request() fails before sending any request.
   NFS generally keeps errors in the open_context, not the mapping,
   so this is more consistent.

4/ If filemap_write_and_write_range() reports any error, still
   check ctx->error.  The value in ctx->error is likely to be
   more useful.  As part of this, NFS_CONTEXT_ERROR_WRITE is
   cleared slightly earlier, before nfs_file_fsync_commit() is called,
   rather than at the start of that function.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-11 22:28:56 -04:00
Chuck Lever
8224b2734a NFS: Add static NFS I/O tracepoints
Tools like tcpdump and rpcdebug can be very useful. But there are
plenty of environments where they are difficult or impossible to
use. For example, we've had customers report I/O failures during
workloads so heavy that collecting network traffic or enabling
RPC debugging are themselves onerous.

The kernel's static tracepoints are lightweight (less likely to
introduce timing changes) and efficient (the trace data is compact).
They also work in scenarios where capturing network traffic is not
possible due to lack of hardware support (some InfiniBand HCAs) or
where data or network privacy is a concern.

Introduce tracepoints that show when an NFS READ, WRITE, or COMMIT
is initiated, and when it completes. Record the arguments and
results of each operation, which are not shown by existing sunrpc
module's tracepoints.

For instance, the recorded offset and count can be used to match an
"initiate" event to a "done" event. If an NFS READ result returns
fewer bytes than requested or zero, seeing the EOF flag can be
probative. Seeing an NFS4ERR_BAD_STATEID result is also indication
of a particular class of problems. The timing information attached
to each event record can often be useful as well.

Usage example:

[root@manet tmp]# trace-cmd record -e nfs:*initiate* -e nfs:*done
/sys/kernel/debug/tracing/events/nfs/*initiate*/filter
/sys/kernel/debug/tracing/events/nfs/*done/filter
Hit Ctrl^C to stop recording
^CKernel buffer statistics:
  Note: "entries" are the entries left in the kernel ring buffer and are not
        recorded in the trace data. They should all be zero.

CPU: 0
entries: 0
overrun: 0
commit overrun: 0
bytes: 3680
oldest event ts:    78.367422
now ts:   100.124419
dropped events: 0
read events: 74

... and so on.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-11 22:20:38 -04:00
Trond Myklebust
1bd5d6d08e NFS: Count the bytes of skipped subrequests in nfs_lock_and_join_requests()
If we skip a subrequest due to a zero refcount, we should still count
the byte range that it covered so that we accurately reconstruct the
original request size.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 16:43:09 -04:00
Trond Myklebust
8b77484f2b NFS: Don't hold the group lock when calling nfs_release_request()
That can deadlock if this is the last reference since
nfs_page_group_destroy() calls nfs_page_group_sync_on_bit().
Note that even if the page was removed from the subpage list,
the req->wb_head could still be pointing to the old head.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 15:36:40 -04:00
Trond Myklebust
5d2a9d9dac NFS: Remove pnfs_generic_transfer_commit_list()
It's pretty much a duplicate of nfs_scan_commit_list() that also
clears the PG_COMMIT_TO_DS flag.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 12:51:40 -04:00
Trond Myklebust
137da553db NFS: nfs_lock_and_join_requests and nfs_scan_commit_list can deadlock
Since the commit list is not ordered, it is possible for nfs_scan_commit_list
to hold a request that nfs_lock_and_join_requests() is waiting for, while
at the same time trying to grab a request that nfs_lock_and_join_requests
already holds.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-09 12:28:01 -04:00
NeilBrown
237f8306c3 NFS: don't expect errors from mempool_alloc().
Commit fbe77c30e9 ("NFS: move rw_mode to nfs_pageio_header")
reintroduced some pointless code that commit 518662e0fc ("NFS: fix
usage of mempools.") had recently removed.

Remove it again.

Cc: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-09-06 12:31:15 -04:00
Trond Myklebust
7af7a5963c Merge branch 'bugfixes' 2017-08-20 13:04:12 -04:00
Trond Myklebust
3bde7afdab NFS: Remove unused parameter gfp_flags from nfs_pageio_init()
Now that the mirror allocation has been moved, the parameter can go.
Also remove the redundant symbol export.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-20 11:35:33 -04:00
Trond Myklebust
2ce209c42c NFS: Wait for requests that are locked on the commit list
If a request is on the commit list, but is locked, we will currently skip
it, which can lead to livelocking when the commit count doesn't reduce
to zero.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:48 -04:00
Trond Myklebust
4b9bb25b36 NFS: Switch to using mapping->private_lock for page writeback lookups.
Switch from using the inode->i_lock for this to avoid contention with
other metadata manipulation.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:48 -04:00
Trond Myklebust
5cb953d4b1 NFS: Use an atomic_long_t to count the number of commits
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:48 -04:00
Trond Myklebust
a6b6d5b85a NFS: Use an atomic_long_t to count the number of requests
Rather than forcing us to take the inode->i_lock just in order to bump
the number.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
e824f99ada NFSv4: Use a mutex to protect the per-inode commit lists
The commit lists can get very large, so using the inode->i_lock can
end up affecting general metadata performance.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
b30d2f04c3 NFS: Refactor nfs_page_find_head_request()
Split out the 2 cases so that we can treat the locking differently.
The issue is that the locking in the pageswapcache cache is highly
linked to the commit list locking.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
bd37d6fce1 NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()
Hide the locking from nfs_lock_and_join_requests() so that we can
separate out the requirements for swapcache pages.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
7e8a30f8b4 NFS: Fix up nfs_page_group_covers_page()
Fix up the test in nfs_page_group_covers_page(). The simplest implementation
is to check that we have a set of intersecting or contiguous subrequests
that connect page offset 0 to nfs_page_length(req->wb_page).

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
1344b7ea17 NFS: Remove unused parameter from nfs_page_group_lock()
nfs_page_group_lock() is now always called with the 'nonblock'
parameter set to 'false'.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
902a4c0046 NFS: Remove nfs_page_group_clear_bits()
At this point, we only expect ever to potentially see PG_REMOVE and
PG_TEARDOWN being set on the subrequests.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00
Trond Myklebust
5b2b5187fa NFS: Fix nfs_page_group_destroy() and nfs_lock_and_join_requests() race cases
Since nfs_page_group_destroy() does not take any locks on the requests
to be freed, we need to ensure that we don't inadvertently free the
request in nfs_destroy_unlinked_subrequests() while the last reference
is being released elsewhere.

Do this by:

1) Taking a reference to the request unless it is already being freed
2) Checking (under the page group lock) if PG_TEARDOWN is already set before
   freeing an unreferenced request in nfs_destroy_unlinked_subrequests()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-08-15 11:54:47 -04:00