Current behaviour: every time a v3 operation is re-sent to the server
we update (double) the timeout. There is no distinction between whether
or not the previous timer had expired before the re-sent happened.

Here's the scenario:
1. Client sends a v3 operation
2. Server RST-s the connection (prior to the timeout) (eg., connection
is immediately reset)
3. Client re-sends a v3 operation but the timeout is now 120sec.

As a result, an application sees 2mins pause before a retry in case
server again does not reply.

Instead, this patch proposes to keep track off when the minor timeout
should happen and if it didn't, then don't update the new timeout.
Value is updated based on the previous value to make timeouts
predictable.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The NFS_CONTEXT_ERROR_WRITE flag (as well as the check of said flag) was
removed by commit 6fbda89b.  The absence of an error check allows
writes to be continually queued up for a server that may no longer be
able to handle them.  Fix it by adding an error check using the generic
error reporting functions.

Fixes: 6fbda89b ("NFS: Replace custom error reporting mechanism with generic one")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs_wb_all() calls filemap_write_and_wait(), which uses
filemap_check_errors() to determine the error to return.
filemap_check_errors() only looks at the mapping->flags and will
therefore only return either -ENOSPC or -EIO.  To ensure that the
correct error is returned on close(), nfs{,4}_file_flush() should call
filemap_check_wb_err() which looks at the errseq value in
mapping->wb_err without consuming it.

Fixes: 6fbda89b ("NFS: Replace custom error reporting mechanism with
generic one")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Caches should be small enough to discard them inline, so do that
instead of using a work queue.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The variable result is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

It looks like this "else" is just a typo.  It turns off nconnect for
NFSv4.0 even though it works for every other version.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

commit 0688e64b ("NFS: Allow signal interruption of NFS4ERR_DELAYed operations")
introduces nfs4_delay_interruptible which also needs an _unsafe version to
avoid the following call trace for the same reason explained in
commit 416ad3c9 ("freezer: add unsafe versions of freezable helpers for NFS")

CPU: 4 PID: 3968 Comm: rm Tainted: G W 5.8.0-rc4 #1
Hardware name: Marvell OcteonTX CN96XX board (DT)
Call trace:
dump_backtrace+0x0/0x1dc
show_stack+0x20/0x30
dump_stack+0xdc/0x150
debug_check_no_locks_held+0x98/0xa0
nfs4_delay_interruptible+0xd8/0x120
nfs4_handle_exception+0x130/0x170
nfs4_proc_rmdir+0x8c/0x220
nfs_rmdir+0xa4/0x360
vfs_rmdir.part.0+0x6c/0x1b0
do_rmdir+0x18c/0x210
__arm64_sys_unlinkat+0x64/0x7c
el0_svc_common.constprop.0+0x7c/0x110
do_el0_svc+0x24/0xa0
el0_sync_handler+0x13c/0x1b8
el0_sync+0x158/0x180
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Better to unregister the file system before destroying the kmem_cache
cache of the inodes, so that the inodes are freed before we are trying
to destroy it. Otherwise, kmem_cache yells that some objects are live.
Signed-off-by: Dan Aloni <dan@kernelim.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Implement client side caching for NFSv4.2 extended attributes. The cache
is a per-inode hashtable, with name/value entries. There is one special
entry for the listxattr cache.

NFS inodes have a pointer to a cache structure. The cache structure is
allocated on demand, freed when the cache is invalidated.

Memory shrinkers keep the size in check. Large entries (> PAGE_SIZE)
are collected by a separate shrinker, and freed more aggressively
than others.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Now that all the lower level code is there to make the RPC calls, hook
it in to the xattr handlers and the listxattr entry point, to make them
available.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Implement the extended attribute procedures for NFSv4.2 extended
attribute support (RFC 8276).
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Make the buf_to_pages_noslab function available to the rest of the NFS
code. Rename it to nfs4_buf_to_pages_noslab to be consistent.

This will be used later in the NFSv4.2 xattr code.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Define the NFS_INO_INVALID_XATTR flag, to be used for the NFSv4.2 xattr
cache, and use it where appropriate.

No functional change as yet.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Until now, change attributes in change_info form were only returned by
directory operations. However, they are also used for the RFC 8276
extended attribute operations, which work on both directories
and regular files.  Modify update_changeattr to deal:

* Rename it to nfs4_update_changeattr and make it non-static.
* Don't always use INO_INVALID_DATA, this isn't needed for a
  directory that only had its extended attributes changed by us.
* Existing callers now always pass in INO_INVALID_DATA.

For the current callers of this function, behavior is unchanged.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

RFC 8276 defines separate ACCESS bits for extended attribute checking.
Query them in nfs_do_access and opendata.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

The only consumer of nfs_access_get_cached_rcu and nfs_access_cached
calls these static functions in order to first try RCU access, and
then locked access.

Combine them in to a single function, and call that. Make this function
available to the rest of the NFS code.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Define the argument and response structures that will be used for
RFC 8276 extended attribute RPC calls, and implement the necessary
functions to encode/decode the extended attribute operations.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Query the server for extended attribute support, and record it
as the NFS_CAP_XATTR flag in the server capabilities.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Set limits for extended attributes (attribute value size and listxattr
buffer size), based on the fs-independent limits (XATTR_*_MAX).

Define the maximum XDR sizes for the RFC 8276 XATTR operations.
In the case of operations that carry a larger payload (SETXATTR,
GETXATTR, LISTXATTR), these exclude that payload, which is added
as separate pages, like other operations do.

Define, much like for read and write operations, the maximum overhead
sizes for get/set/listxattr, and use them to limit the maximum payload
size for those operations, in combination with the channel attributes.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Add client-side only definitions for user extended
attributes (RFC8276). These are the access bits
as used by the client code, and the CLNT procedure
number definition.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Pull in the commit that is common to both the NFS client and server xattr
implementation from git://git.linux-nfs.org/projects/cel/cel-2.6.git nfsd-5.9
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Add definitions for the new operations, errors and flags as defined
in RFC 8276 (File System Extended Attributes in NFSv4).
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Make sure we specify the layout segment range when calculating the
mirror count. In theory, that number could depend on the range to
which we're writing.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Both nfs_pageio_reset_read_mds() and nfs_pageio_reset_write_mds()
do call pnfs_generic_pg_cleanup() for us.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

If the application uses the AT_STATX_DONT_SYNC flag after doing readdir(),
then we should still mark the parent inode as seeing a readdirplus hit.
That ensures that we continue to use readdirplus in the 'ls -l' type
of workflow to do fast lookups of the dentries.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Pull Xtensa fixes from Max Filippov:

 - fix __sync_fetch_and_{and,or}_4 declarations to avoid build warning

 - update *pos in cpuinfo_op.next to avoid runtime warning

 - use for_each_set_bit in xtensa_pmu_irq_handler instead of open-coding
   it

* tag 'xtensa-20200712' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: simplify xtensa_pmu_irq_handler
  xtensa: update *pos in cpuinfo_op.next
  xtensa: fix __sync_fetch_and_{and,or}_4 declarations

Pull io_uring fixes from Jens Axboe:
 "Two late fixes again:

   - Fix missing msg_name assignment in certain cases (Pavel)

   - Correct a previous fix for full coverage (Pavel)"

* tag 'io_uring-5.8-2020-07-12' of git://git.kernel.dk/linux-block:
  io_uring: fix not initialised work->flags
  io_uring: fix missing msg_name assignment

Pull btrfs fixes from David Sterba:
 "Two refcounting fixes and one prepartory patch for upcoming splice
  cleanup:

   - fix double put of block group with nodatacow

   - fix missing block group put when remounting with discard=async

   - explicitly set splice callback (no functional change), to ease
     integrating splice cleanup patches"

* tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: wire up iter_file_splice_write
  btrfs: fix double put of block group with nocow
  btrfs: discard: add missing put when grabbing block group from unused list

59960b9d ("io_uring: fix lazy work init") tried to fix missing
io_req_init_async(), but left out work.flags and hash. Do it earlier.

Fixes: 7cdaf587 ("io_uring: avoid whole io_wq_work copy for requests completed inline")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Ensure to set msg.msg_name for the async portion of send/recvmsg,
as the header copy will copy to/from it.

Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull RISC-V fixes from Palmer Dabbelt:
 "I have a few KGDB-related fixes. They're mostly fixes for build
  warnings, but there's also:

   - Support for the qSupported and qXfer packets, which are necessary
     to pass around GDB XML information which we need for the RISC-V GDB
     port to fully function.

   - Users can now select STRICT_KERNEL_RWX instead of forcing it on"

* tag 'riscv-for-linus-5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Avoid kgdb.h including gdb_xml.h to solve unused-const-variable warning
  kgdb: Move the extern declaration kgdb_has_hit_break() to generic kgdb.h
  riscv: Fix "no previous prototype" compile warning in kgdb.c file
  riscv: enable the Kconfig prompt of STRICT_KERNEL_RWX
  kgdb: enable arch to support XML packet.

Pull SCSI fixes from James Bottomley:
 "Five small fixes, four in driver and one in the SCSI Parallel
  transport, which fixes an incredibly old bug so I suspect no-one has
  actually used the functionality it fixes"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: dh: Add Fujitsu device to devinfo and dh lists
  scsi: mpt3sas: Fix error returns in BRM_status_show
  scsi: mpt3sas: Fix unlock imbalance
  scsi: iscsi: Change iSCSI workqueue max_active back to 1
  scsi: scsi_transport_spi: Fix function pointer check

Pull xen fix from Juergen Gross:
 "Just one fix of a recent patch (double free in an error path)"

* tag 'for-linus-5.8b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/xenbus: Fix a double free in xenbus_map_ring_pv()

Pull powerpc fix from Michael Ellerman:
 "One fix for a crash/soft lockup on Power8, caused by the exception
  rework we did in v5.7.

  Thanks to Paul Menzel and Nicholas Piggin"

* tag 'powerpc-5.8-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/exception: Fix 0x1500 interrupt handler crash

Pull libnvdimm fix from Dan Williams:
 "A one-line Fix for key ring search permissions to address a regression
  from -rc1"

* tag 'libnvdimm-fix-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm/security: Fix key lookup permissions

Pull cifs fixes from Steve French:
 "Four cifs/smb3 fixes: the three for stable fix problems found recently
  with change notification including a reference count leak"

* tag '5.8-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal module version number
  cifs: fix reference leak for tlink
  smb3: fix unneeded error message on change notify
  cifs: remove the retry in cifs_poxis_lock_set
  smb3: fix access denied on change notify request to some servers

Pull coding style terminology documentation from Dan Williams:
 "The discussion has tapered off as well as the incoming ack, review,
  and sign-off tags. I did not see a reason to wait for the next merge
  window"

* tag 'inclusive-terminology' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/linux:
  CodingStyle: Inclusive Terminology

Pull networking fixes from David Miller:

 1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking
    BPF programs, from Maciej Żenczykowski.

 2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu
    Mariappan.

 3) Slay memory leak in nl80211 bss color attribute parsing code, from
    Luca Coelho.

 4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin.

 5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric
    Dumazet.

 6) xsk code dips too deeply into DMA mapping implementation internals.
    Add dma_need_sync and use it. From Christoph Hellwig

 7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko.

 8) Check for disallowed attributes when loading flow dissector BPF
    programs. From Lorenz Bauer.

 9) Correct packet injection to L3 tunnel devices via AF_PACKET, from
    Jason A. Donenfeld.

10) Don't advertise checksum offload on ipa devices that don't support
    it. From Alex Elder.

11) Resolve several issues in TCP MD5 signature support. Missing memory
    barriers, bogus options emitted when using syncookies, and failure
    to allow md5 key changes in established states. All from Eric
    Dumazet.

12) Fix interface leak in hsr code, from Taehee Yoo.

13) VF reset fixes in hns3 driver, from Huazhong Tan.

14) Make loopback work again with ipv6 anycast, from David Ahern.

15) Fix TX starvation under high load in fec driver, from Tobias
    Waldekranz.

16) MLD2 payload lengths not checked properly in bridge multicast code,
    from Linus Lüssing.

17) Packet scheduler code that wants to find the inner protocol
    currently only works for one level of VLAN encapsulation. Allow
    Q-in-Q situations to work properly here, from Toke
    Høiland-Jørgensen.

18) Fix route leak in l2tp, from Xin Long.

19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport
    support and various protocols. From Martin KaFai Lau.

20) Fix socket cgroup v2 reference counting in some situations, from
    Cong Wang.

21) Cure memory leak in mlx5 connection tracking offload support, from
    Eli Britstein.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits)
  mlxsw: pci: Fix use-after-free in case of failed devlink reload
  mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON()
  net: macb: fix call to pm_runtime in the suspend/resume functions
  net: macb: fix macb_suspend() by removing call to netif_carrier_off()
  net: macb: fix macb_get/set_wol() when moving to phylink
  net: macb: mark device wake capable when "magic-packet" property present
  net: macb: fix wakeup test in runtime suspend/resume routines
  bnxt_en: fix NULL dereference in case SR-IOV configuration fails
  libbpf: Fix libbpf hashmap on (I)LP32 architectures
  net/mlx5e: CT: Fix memory leak in cleanup
  net/mlx5e: Fix port buffers cell size value
  net/mlx5e: Fix 50G per lane indication
  net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash
  net/mlx5e: Fix VXLAN configuration restore after function reload
  net/mlx5e: Fix usage of rcu-protected pointer
  net/mxl5e: Verify that rpriv is not NULL
  net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode
  net/mlx5: Fix eeprom support for SFP module
  cgroup: Fix sock_cgroup_data on big-endian.
  selftests: bpf: Fix detach from sockmap tests
  ...