This reverts commit 4e379d36.

This commit opens up a race between the recovery code and the open code.
Reported-by: Olga Kornievskaia <aglo@umich.edu>
Cc: stable@vger.kernel # v4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If we have an OPEN_DOWNGRADE and CLOSE race with one another, we want
to ensure that the layout is forgotten by the client, so that we
start afresh with a new layoutget.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

The helper pnfs_roc() has already verified that we have no delegations,
and no further open files, hence no outstanding I/O and it has marked
all the return-on-close lsegs as being invalid.
Furthermore, it sets the NFS_LAYOUT_RETURN bit, thus serialising the
close/delegreturn with all future layoutget calls on this inode.

The checks in pnfs_roc_drain() for valid layout segments are therefore
redundant: those cannot exist until another layoutget completes.
The other check for whether or not NFS_LAYOUT_RETURN is set, actually
causes a hang, since we already know that we hold that flag.

To fix, we therefore strip out all the functionality in pnfs_roc_drain()
except the retrieval of the barrier state, and then rename the function
accordingly.
Reported-by: Christoph Hellwig <hch@infradead.org>
Fixes: 5c4a79fb ("Don't prevent layoutgets when doing return-on-close")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

generic_file_write_iter() will already do an fsync on our behalf
if the file descriptor is O_SYNC or the file is marked as IS_SYNC.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 7b0ce60c ("SUNRPC: Drop double-underscores from rpc_cmp_addr{4|6}()")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Chuck reports seeing cases where a GETATTR that happens to race
with an asynchronous WRITE is overriding the file size, despite
the attribute barrier being set by the writeback code.

The culprit turns out to be the check in nfs_ctime_need_update(),
which sees that the ctime is newer than the cached ctime, and
assumes that it is safe to override the attribute barrier.
This patch removes that override, and ensures that attribute
barriers are always respected.
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: a08a8cd3 ("NFS: Add attribute update barriers to NFS writebacks")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

* layoutfixes:
  NFSv4.1/pnfs: Remove redundant wakeup in pnfs_send_layoutreturn()
  NFSv4.1/pnfs: Remove redundant check in pnfs_layoutgets_blocked()
  NFSv4.1/pnfs: Remove redundant lo->plh_block_lgets in layoutreturn
  NFSv4.1/pnfs: Don't prevent layoutgets when doing return-on-close
  NFSv4.1/pnfs: Fix serialisation of layout return and layoutget
  NFSv4.1/pnfs: Remove redundant checks in pnfs_layoutgets_blocked()
  pNFS: Tighten up locking around DS commit buckets

* bugfixes:
  SUNRPC: Fix a thinko in xs_connect()
  NFSv4.1/pNFS: Fix borken function _same_data_server_addrs_locked()
  NFS: nfs_set_pgio_error sometimes misses errors

NFS: NFS over RDMA Client Side Changes

These patches improve both client performance and scalability, most notably
by increasing the maixmum allowed rsize and wsize and by increasing the number
of RDMA "credits".  There are also several bugfixes, such as correcting how
WRITE compounds are encoded and fixing large NFS symlink operations.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

And call nfs_file_clear_open_context() directly.  This makes it obvious
that nfs_file_release() will always return 0.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

All nfs_write_inode() does is pass its arguments to
nfs_commit_unstable_pages().  Let's cut out the middle man and have
nfs_write_pages() do the work directly.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

All these functions do is call nfs41_ping_server() without adding
anything.  Let's remove them and give nfs41_ping_server() a better name
instead.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

The idmap_init() and idmap_quit() functions only exist to call the
_keyring() version.  Let's just call the keyring() functions directly.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

They already exist and do the exact same thing.  Let's save ourselves
several lines of code!
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

This function is to help determine if two sockaddrs are really the same
socket.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

I'm planning on using these functions inside the client, so remove the
underscores to make it feel like I'm using a public interface.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs_readdir_xdr_to_array() uses both a cache array and an array of
pages, so I rename these functions to make it clearer how the code
works.  nfs_readdir_large_page() becomes nfs_readdir_alloc_pages()
because this function has absolutely nothing to do with setting up a
large page.  nfs_readdir_free_pagearray() becomes
nfs_readdir_free_pages() to stay consistent with the new alloc_pages()
function.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

This variable is initialized to NULL and is never modified before being
passed to nfs_readdir_free_large_page().  But that's okay, because
nfs_readdir_free_large_page() only seems to exist as a way of calling
nfs_readdir_free_pagearray() without this parameter.  Let's simplify by
removing pages_ptr and nfs_readdir_free_pagearray().
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We already know that pg_lseg is NULL here.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We generally want to read and write to a block device that's used by
the pNFS block layout client (and even if it's read only the server
has no way of telling us).  Add FMODE_WRITE to the mode argument
so that we don't incorrectly tell the block driver that we want a
read-only open.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Instead of overwriting kernel memory reject too long signatures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We need to replace the __be32 with a void pointer to do proper arithmentics
on the virtual addresses so that we can get the right page pointers.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We need to include the first u32 for the number of entries.  Add a helper
for the calculation instead of opencoding it so that it's in one place.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

---Steps to Reproduce--
<nfs-server>
# cat /etc/exports
/nfs/referal  *(rw,insecure,no_subtree_check,no_root_squash,crossmnt)
/nfs/old      *(ro,insecure,subtree_check,root_squash,crossmnt)

<nfs-client>
# mount -t nfs nfs-server:/nfs/ /mnt/
# ll /mnt/*/

<nfs-server>
# cat /etc/exports
/nfs/referal   *(rw,insecure,no_subtree_check,no_root_squash,crossmnt,refer=/nfs/old/@nfs-server)
/nfs/old       *(ro,insecure,subtree_check,root_squash,crossmnt)
# service nfs restart

<nfs-client>
# ll /mnt/*/    --->>>>> oops here

[ 5123.102925] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 5123.103363] IP: [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.103752] PGD 587b9067 PUD 3cbf5067 PMD 0
[ 5123.104131] Oops: 0000 [#1]
[ 5123.104529] Modules linked in: nfsv4(OE) nfs(OE) fscache(E) nfsd(OE) xfs libcrc32c iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi coretemp crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev vmw_balloon parport_pc parport i2c_piix4 shpchp auth_rpcgss nfs_acl vmw_vmci lockd grace sunrpc vmwgfx drm_kms_helper ttm drm mptspi serio_raw scsi_transport_spi e1000 mptscsih mptbase ata_generic pata_acpi [last unloaded: nfsd]
[ 5123.105887] CPU: 0 PID: 15853 Comm: ::1-manager Tainted: G           OE   4.2.0-rc6+ #214
[ 5123.106358] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/20/2014
[ 5123.106860] task: ffff88007620f300 ti: ffff88005877c000 task.ti: ffff88005877c000
[ 5123.107363] RIP: 0010:[<ffffffffa03ed38b>]  [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.107909] RSP: 0018:ffff88005877fdb8  EFLAGS: 00010246
[ 5123.108435] RAX: ffff880053f3bc00 RBX: ffff88006ce6c908 RCX: ffff880053a0d240
[ 5123.108968] RDX: ffffea0000e6d940 RSI: ffff8800399a0000 RDI: ffff88006ce6c908
[ 5123.109503] RBP: ffff88005877fe28 R08: ffffffff81c708a0 R09: 0000000000000000
[ 5123.110045] R10: 00000000000001a2 R11: ffff88003ba7f5c8 R12: ffff880054c55800
[ 5123.110618] R13: 0000000000000000 R14: ffff880053a0d240 R15: ffff880053a0d240
[ 5123.111169] FS:  0000000000000000(0000) GS:ffffffff81c27000(0000) knlGS:0000000000000000
[ 5123.111726] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5123.112286] CR2: 0000000000000000 CR3: 0000000054cac000 CR4: 00000000001406f0
[ 5123.112888] Stack:
[ 5123.113458]  ffffea0000e6d940 ffff8800399a0000 00000000000167d0 0000000000000000
[ 5123.114049]  0000000000000000 0000000000000000 0000000000000000 00000000a7ec82c6
[ 5123.114662]  ffff88005877fe18 ffffea0000e6d940 ffff8800399a0000 ffff880054c55800
[ 5123.115264] Call Trace:
[ 5123.115868]  [<ffffffffa03fb44b>] nfs4_try_migration+0xbb/0x220 [nfsv4]
[ 5123.116487]  [<ffffffffa03fcb3b>] nfs4_run_state_manager+0x4ab/0x7b0 [nfsv4]
[ 5123.117104]  [<ffffffffa03fc690>] ? nfs4_do_reclaim+0x510/0x510 [nfsv4]
[ 5123.117813]  [<ffffffff810a4527>] kthread+0xd7/0xf0
[ 5123.118456]  [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160
[ 5123.119108]  [<ffffffff816d9cdf>] ret_from_fork+0x3f/0x70
[ 5123.119723]  [<ffffffff810a4450>] ? kthread_worker_fn+0x160/0x160
[ 5123.120329] Code: 4c 8b 6a 58 74 17 eb 52 48 8d 55 a8 89 c6 4c 89 e7 e8 4a b5 ff ff 8b 45 b0 85 c0 74 1c 4c 89 f9 48 8b 55 90 48 8b 75 98 48 89 df <41> ff 55 00 3d e8 d8 ff ff 41 89 c6 74 cf 48 8b 4d c8 65 48 33
[ 5123.121643] RIP  [<ffffffffa03ed38b>] nfs4_proc_get_locations+0x9b/0x120 [nfsv4]
[ 5123.122308]  RSP <ffff88005877fdb8>
[ 5123.122942] CR2: 0000000000000000

Fixes: ec011fe8 ("NFS: Introduce a vector of migration recovery ops")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

It is rather pointless to test the value of transport->inet after
calling xs_reset_transport(), since it will always be zero, and
so we will never see any exponential back off behaviour.
Also don't force early connections for SOFTCONN tasks. If the server
disconnects us, we should respect the exponential backoff.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

- Switch back to using list_for_each_entry(). Fixes an incorrect test
  for list NULL termination.
- Do not assume that lists are sorted.
- Finally, consider an existing entry to match if it consists of a subset
  of the addresses in the new entry.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We should ensure that we always set the pgio_header's error field
if a READ or WRITE RPC call returns an error. The current code depends
on 'hdr->good_bytes' always being initialised to a large value, which
is not always done correctly by callers.
When this happens, applications may end up missing important errors.

Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

pnfs_clear_layoutreturn_waitbit() should already be calling
rpc_wake_up(&NFS_SERVER(ino)->roc_rpcwaitq) for us.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

layoutget now should already be serialised w.r.t. layout returns
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

The NFS_LAYOUT_RETURN bit already suffices to ensure that layoutget
is blocked.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If there is an outstanding return-on-close, then we just want new
layoutget requests to wait rather than fail.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We should always test for outstanding layout returns, whether or not
pnfs_should_retry_layoutget() is true.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If there are no valid layout segments, then we should already have
checked in pnfs_update_layout() whether or not this is the first
layoutget.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

I'm not aware of any bugreports around this issue, but the locking
around the pnfs_commit_bucket is inconsistent at best. This patch
tightens it up by ensuring that the 'bucket->committing' list is always
changed atomically w.r.t. the 'bucket->clseg' layout segment tracking.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

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

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

It is unusual to combine the open flags O_RDONLY and O_EXCL, but
it appears that libre-office does just that.

[pid  3250] stat("/home/USER/.config", {st_mode=S_IFDIR|0700, st_size=8192, ...}) = 0
[pid  3250] open("/home/USER/.config/libreoffice/4-suse/user/extensions/buildid", O_RDONLY|O_EXCL <unfinished ...>

NFSv4 takes O_EXCL as a sign that a setattr command should be sent,
probably to reset the timestamps.

When it was an O_RDONLY open, the SETATTR command does not
identify any actual attributes to change.
If no delegation was provided to the open, the SETATTR uses the
all-zeros stateid and the request is accepted (at least by the
Linux NFS server - no harm, no foul).

If a read-delegation was provided, this is used in the SETATTR
request, and a Netapp filer will justifiably claim
NFS4ERR_BAD_STATEID, which the Linux client takes as a sign
to retry - indefinitely.

So only treat O_EXCL specially if O_CREAT was also given.
Signed-off-by: NeilBrown <neilb@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Commit 1d3d4437 "vmscan: per-node deferred work" have made
register_shrinker can return an intergater error.

If register_shrinker() fail, the later unregister_shrinker() will
 cause a NULL pointer access.

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

The current limit of 32 bytes artificially limits the name string that
we end up stuffing into NFSv4.x client ID blobs. If you have multiple
hosts with long hostnames that only differ near the end, then this can
cause NFSv4 client ID collisions.

Linux nodenames are actually limited to __NEW_UTS_LEN bytes (64), so use
that as the limit instead. Also, use XDR_QUADLEN to specify the slack
length, just for clarity and in case someone in the future changes this
to something not evenly divisible by 4.
Reported-by: Michael Skralivetsky <michael.skralivetsky@primarydata.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Prevent a potential deadlock.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>