These routines are used by server and client code, so having them in a
separate header would be best.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The fscache code will currently bleat a "non-unique superblock keys"
warning even if the user is mounting without the 'fsc' option.

There should be no reason to even initialise the superblock cache cookie
unless we're planning on using fscache for something, so ensure that we
check for the NFS_OPTION_FSCACHE flag before calling into the fscache
code.
Reported-by: NPaweł Sikora <pawel.sikora@agmk.net>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: David Howells <dhowells@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide a stub nfs_fscache_wait_on_invalidate() function for when
CONFIG_NFS_FSCACHE=n lest the following error appear:

  fs/nfs/inode.c: In function 'nfs_invalidate_mapping':
  fs/nfs/inode.c:887:2: error: implicit declaration of function 'nfs_fscache_wait_on_invalidate' [-Werror=implicit-function-declaration]
  cc1: some warnings being treated as errors
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Reported-by: NVineet Gupta <Vineet.Gupta1@synopsys.com>
Reported-by: NBorislav Petkov <bp@alien8.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

nfs4_file_open() should open files for fscaching.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

nfs_migrate_page() does not wait for FS-Cache to finish with a page, probably
leading to the following bad-page-state:

 BUG: Bad page state in process python-bin  pfn:17d39b
 page:ffffea00053649e8 flags:004000000000100c count:0 mapcount:0 mapping:(null)
index:38686 (Tainted: G    B      ---------------- )
 Pid: 31053, comm: python-bin Tainted: G    B      ----------------
2.6.32-71.24.1.el6.x86_64 #1
 Call Trace:
 [<ffffffff8111bfe7>] bad_page+0x107/0x160
 [<ffffffff8111ee69>] free_hot_cold_page+0x1c9/0x220
 [<ffffffff8111ef19>] __pagevec_free+0x59/0xb0
 [<ffffffff8104b988>] ? flush_tlb_others_ipi+0x128/0x130
 [<ffffffff8112230c>] release_pages+0x21c/0x250
 [<ffffffff8115b92a>] ? remove_migration_pte+0x28a/0x2b0
 [<ffffffff8115f3f8>] ? mem_cgroup_get_reclaim_stat_from_page+0x18/0x70
 [<ffffffff81122687>] ____pagevec_lru_add+0x167/0x180
 [<ffffffff811226f8>] __lru_cache_add+0x58/0x70
 [<ffffffff81122731>] lru_cache_add_lru+0x21/0x40
 [<ffffffff81123f49>] putback_lru_page+0x69/0x100
 [<ffffffff8115c0bd>] migrate_pages+0x13d/0x5d0
 [<ffffffff81122687>] ? ____pagevec_lru_add+0x167/0x180
 [<ffffffff81152ab0>] ? compaction_alloc+0x0/0x370
 [<ffffffff8115255c>] compact_zone+0x4cc/0x600
 [<ffffffff8111cfac>] ? get_page_from_freelist+0x15c/0x820
 [<ffffffff810672f4>] ? check_preempt_wakeup+0x1c4/0x3c0
 [<ffffffff8115290e>] compact_zone_order+0x7e/0xb0
 [<ffffffff81152a49>] try_to_compact_pages+0x109/0x170
 [<ffffffff8111e94d>] __alloc_pages_nodemask+0x5ed/0x850
 [<ffffffff814c9136>] ? thread_return+0x4e/0x778
 [<ffffffff81150d43>] alloc_pages_vma+0x93/0x150
 [<ffffffff81167ea5>] do_huge_pmd_anonymous_page+0x135/0x340
 [<ffffffff814cb6f6>] ? rwsem_down_read_failed+0x26/0x30
 [<ffffffff81136755>] handle_mm_fault+0x245/0x2b0
 [<ffffffff814ce383>] do_page_fault+0x123/0x3a0
 [<ffffffff814cbdf5>] page_fault+0x25/0x30

nfs_migrate_page() calls nfs_fscache_release_page() which doesn't actually wait
- even if __GFP_WAIT is set.  The reason that doesn't wait is that
fscache_maybe_release_page() might deadlock the allocator as the work threads
writing to the cache may all end up sleeping on memory allocation.

However, I wonder if that is actually a problem.  There are a number of things
I can do to deal with this:

 (1) Make nfs_migrate_page() wait.

 (2) Make fscache_maybe_release_page() honour the __GFP_WAIT flag.

 (3) Set a timeout around the wait.

 (4) Make nfs_migrate_page() return an error if the page is still busy.

For the moment, I'll select (2) and (4).
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJeff Layton <jlayton@redhat.com>

Use the new FS-Cache invalidation facility from NFS to deal with foreign
changes being detected on the server rather than attempting to retire the old
cookie and get a new one.

The problem with the old method was that NFS did not wait for all outstanding
storage and retrieval ops on the cache to complete.  There was no automatic
wait between the calls to ->readpages() and calls to invalidate_inode_pages2()
as the latter can only wait on locked pages that have been added to the
pagecache (which they haven't yet on entry to ->readpages()).

This was leading to oopses like the one below when an outstanding read got cut
off from its cookie by a premature release.

BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8
IP: [<ffffffffa0075118>] __fscache_read_or_alloc_pages+0x1dd/0x315 [fscache]
PGD 15889067 PUD 15890067 PMD 0
Oops: 0000 [#1] SMP
CPU 0
Modules linked in: cachefiles nfs fscache auth_rpcgss nfs_acl lockd sunrpc

Pid: 4544, comm: tar Not tainted 3.1.0-rc4-fsdevel+ #1064                  /DG965RY
RIP: 0010:[<ffffffffa0075118>]  [<ffffffffa0075118>] __fscache_read_or_alloc_pages+0x1dd/0x315 [fscache]
RSP: 0018:ffff8800158799e8  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800070d41e0 RCX: ffff8800083dc1b0
RDX: 0000000000000000 RSI: ffff880015879960 RDI: ffff88003e627b90
RBP: ffff880015879a28 R08: 0000000000000002 R09: 0000000000000002
R10: 0000000000000001 R11: ffff880015879950 R12: ffff880015879aa4
R13: 0000000000000000 R14: ffff8800083dc158 R15: ffff880015879be8
FS:  00007f671e9d87c0(0000) GS:ffff88003bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000000000a8 CR3: 000000001587f000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process tar (pid: 4544, threadinfo ffff880015878000, task ffff880015875040)
Stack:
 ffffffffa00b1759 ffff8800070dc158 ffff8800000213da ffff88002a286508
 ffff880015879aa4 ffff880015879be8 0000000000000001 ffff88002a2866e8
 ffff880015879a88 ffffffffa00b20be 00000000000200da ffff880015875040
Call Trace:
 [<ffffffffa00b1759>] ? nfs_fscache_wait_bit+0xd/0xd [nfs]
 [<ffffffffa00b20be>] __nfs_readpages_from_fscache+0x7e/0x13f [nfs]
 [<ffffffff81095fe7>] ? __alloc_pages_nodemask+0x156/0x662
 [<ffffffffa0098763>] nfs_readpages+0xee/0x187 [nfs]
 [<ffffffff81098a5e>] __do_page_cache_readahead+0x1be/0x267
 [<ffffffff81098942>] ? __do_page_cache_readahead+0xa2/0x267
 [<ffffffff81098d7b>] ra_submit+0x1c/0x20
 [<ffffffff8109900a>] ondemand_readahead+0x28b/0x29a
 [<ffffffff810990ce>] page_cache_sync_readahead+0x38/0x3a
 [<ffffffff81091d8a>] generic_file_aio_read+0x2ab/0x67e
 [<ffffffffa008cfbe>] nfs_file_read+0xa4/0xc9 [nfs]
 [<ffffffff810c22c4>] do_sync_read+0xba/0xfa
 [<ffffffff810a62c9>] ? might_fault+0x4e/0x9e
 [<ffffffff81177a47>] ? security_file_permission+0x7b/0x84
 [<ffffffff810c25dd>] ? rw_verify_area+0xab/0xc8
 [<ffffffff810c29a4>] vfs_read+0xaa/0x13a
 [<ffffffff810c2a79>] sys_read+0x45/0x6c
 [<ffffffff813ac37b>] system_call_fastpath+0x16/0x1b
Reported-by: NMark Moseley <moseleymark@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

But the kernel decided to call it "origin" instead.  Fix most of the
sites.
Acked-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The writeback code is already capable of passing errors back to user space
by means of the open_context->error. In the case of ENOSPC, Neil Brown
is reporting seeing 2 errors being returned.

Neil writes:

"e.g. if /mnt2/ if an nfs mounted filesystem that has no space then

strace dd if=/dev/zero conv=fsync >> /mnt2/afile count=1

reported Input/output error and the relevant parts of the strace output are:

write(1, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 512) = 512
fsync(1)                                = -1 EIO (Input/output error)
close(1)                                = -1 ENOSPC (No space left on device)"

Neil then shows that the duplication of error messages appears to be due to
the use of the PageError() mechanism, which causes filemap_fdatawait_range
to return the extra EIO. The regression was introduced by
commit 7b281ee0 (NFS: fsync() must exit
with an error if page writeback failed).

Fix this by removing the call to SetPageError(), and just relying on
open_context->error reporting the ENOSPC back to fsync().
Reported-by: NNeil Brown <neilb@suse.de>
Tested-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [3.6+]

If an RPC call is interrupted, assume that the server hasn't processed
the RPC call so that the next time we use the slot, we know that if we
get a NFS4ERR_SEQ_MISORDERED or NFS4ERR_SEQ_FALSE_RETRY, we just have
to bump the sequence number.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Shave a few bytes off the slot table size by moving the RPC timestamp
into the sequence results.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the server returns NFS4ERR_SEQ_MISORDERED, it could be a sign
that the slot was retired at some point. Retry the attempt after
reinitialising the slot sequence number to 1.

Also add a handler for NFS4ERR_SEQ_FALSE_RETRY. Just bump the slot
sequence number and retry...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the inode has no links, then we should force a new lookup.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It is almost always wrong for NFS to call drop_nlink() after removing a
file. What we really want is to mark the inode's attributes for
revalidation, and we want to ensure that the VFS drops it if we're
reasonably sure that this is the final unlink().
Do the former using the usual cache validity flags, and the latter
by testing if inode->i_nlink == 1, and clearing it in that case.

This also fixes the following warning reported by Neil Brown and
Jeff Layton (among others).

[634155.004438] WARNING:
at /home/abuild/rpmbuild/BUILD/kernel-desktop-3.5.0/lin [634155.004442]
Hardware name: Latitude E6510 [634155.004577]  crc_itu_t crc32c_intel
snd_hwdep snd_pcm snd_timer snd soundcor [634155.004609] Pid: 13402, comm:
bash Tainted: G        W    3.5.0-36-desktop # [634155.004611] Call Trace:
[634155.004630]  [<ffffffff8100444a>] dump_trace+0xaa/0x2b0
[634155.004641]  [<ffffffff815a23dc>] dump_stack+0x69/0x6f
[634155.004653]  [<ffffffff81041a0b>] warn_slowpath_common+0x7b/0xc0
[634155.004662]  [<ffffffff811832e4>] drop_nlink+0x34/0x40
[634155.004687]  [<ffffffffa05bb6c3>] nfs_dentry_iput+0x33/0x70 [nfs]
[634155.004714]  [<ffffffff8118049e>] dput+0x12e/0x230
[634155.004726]  [<ffffffff8116b230>] __fput+0x170/0x230
[634155.004735]  [<ffffffff81167c0f>] filp_close+0x5f/0x90
[634155.004743]  [<ffffffff81167cd7>] sys_close+0x97/0x100
[634155.004754]  [<ffffffff815c3b39>] system_call_fastpath+0x16/0x1b
[634155.004767]  [<00007f2a73a0d110>] 0x7f2a73a0d10f
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [3.3+]

There is no need to cache stale inodes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This list was designed to store struct nfs4_client in the client side.
But nfs4_client was obsolete and has been removed from the source code.
So remove the unused list.
Signed-off-by: NYanchuan Nian <ycnian@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove duplicate function declaration in internal.h
Signed-off-by: NYanchuan Nian <ycnian@gmail.com>
[Trond: Added nfs_pageio_init_read, which suffered from the same problem]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In rare circumstances, nfs_clone_server() of a v2 or v3 server can get
an error between setting server->destory (to nfs_destroy_server), and
calling nfs_start_lockd (which will set server->nlm_host).

If this happens, nfs_clone_server will call nfs_free_server which
will call nfs_destroy_server and thence nlmclnt_done(NULL).  This
causes the NULL to be dereferenced.

So add a guard to only call nlmclnt_done() if ->nlm_host is not NULL.

The other guards there are irrelevant as nlm_host can only be non-NULL
if one of these flags are set - so remove those tests.  (Thanks to Trond
for this suggestion).

This is suitable for any stable kernel since 2.6.25.

Cc: stable@vger.kernel.org
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently, when an RPCSEC_GSS context has expired or is non-existent
and the users (Kerberos) credentials have also expired or are non-existent,
the client receives the -EKEYEXPIRED error and tries to refresh the context
forever.  If an application is performing I/O, or other work against the share,
the application hangs, and the user is not prompted to refresh/establish their
credentials. This can result in a denial of service for other users.

Users are expected to manage their Kerberos credential lifetimes to mitigate
this issue.

Move the -EKEYEXPIRED handling into the RPC layer. Try tk_cred_retry number
of times to refresh the gss_context, and then return -EACCES to the application.
Signed-off-by: NAndy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The NFS DIO code will dirty pages that catch read responses in order to
handle the case where someone is doing DIO reads into an mmapped buffer.
The existing code doesn't really do the right thing though since it
doesn't take into account the case where we might be attempting to read
past the EOF.

Fix the logic in that code to only dirty pages that ended up receiving
data from the read. Note too that it really doesn't matter if
NFS_IOHDR_ERROR is set or not. All that matters is if the page was
altered by the read.

Cc: Fred Isaman <iisaman@netapp.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Eryu provided a test program that would segfault when attempting to read
past the EOF on file that was opened O_DIRECT. The buffer given to the
read() call was on the stack, and when he attempted to read past it it
would scribble over the rest of the stack page.

If we hit the end of the file on a DIO READ request, then we don't want
to zero out the rest of the buffer. These aren't pagecache pages after
all, and there's no guarantee that the buffers that were passed in
represent entire pages.

Cc: <stable@vger.kernel.org> # v3.5+
Cc: Fred Isaman <iisaman@netapp.com>
Reported-by: NEryu Guan <eguan@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the server sends us a target that looks like an outlier, but
is lower than the existing target, then respect it anyway.
However defer actually updating the generation counter until
we get a target that doesn't look like an outlier.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Most (all) NFS4ERR_BADSLOT errors are due to the client failing to
respect the server's sr_highest_slotid limit. This mainly happens
due to reordered RPC requests.
The way to handle it is simply to drop the slot that we're using,
and retry using the new highest_slotid limits.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Jian reported that the following sequence would leave "testfile" with
corrupt data:

    # mount localhost:/export /mnt/nfs/ -o vers=3
    # echo abc > /mnt/nfs/testfile; echo def >> /export/testfile; echo ghi >> /mnt/nfs/testfile
    # cat -v /export/testfile
    abc
    ^@^@^@^@ghi

While there's no locking involved here, the operations are serialized,
so CTO should prevent corruption.

The first write to the file is fine and writes 4 bytes. The file is then
extended on the server. When it's reopened a GETATTR is issued and the
size change is noticed. This causes NFS_INO_INVALID_DATA to be set on
the file. Because the file is opened for write only,
nfs_want_read_modify_write() returns 0 to nfs_write_begin().
nfs_updatepage then calls nfs_write_pageuptodate() to see if it should
extend the nfs_page to cover the whole page. NFS_INO_INVALID_DATA is
still set on the file at that point, but that flag is ignored and
nfs_pageuptodate erroneously extends the write to cover the whole page,
with the write done on the server side filled in with zeroes.

This patch just has that function check for NFS_INO_INVALID_DATA in
addition to NFS_INO_REVAL_PAGECACHE. This fixes the bug, but looking
over the code, I wonder if we might have a similar bug in
nfs_revalidate_size(). The difference between those two flags is very
subtle, so it seems like we ought to be checking for
NFS_INO_INVALID_DATA in most of the places that we look for
NFS_INO_REVAL_PAGECACHE.

I believe this is regression introduced by commit 8d197a56. The code
did check for NFS_INO_INVALID_DATA prior to that patch.

Original bug report is here:

    https://bugzilla.redhat.com/show_bug.cgi?id=885743

Cc: <stable@vger.kernel.org> # 3.5+
Reported-by: NJian Li <jiali@redhat.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Commit 1f1ea6c2 "NFSv4: Fix buffer overflow checking in
__nfs4_get_acl_uncached" accidently dropped the checking for too small
result buffer length.

If someone uses getxattr on "system.nfs4_acl" on an NFSv4 mount
supporting ACLs, the ACL has not been cached and the buffer suplied is
too short, we still copy the complete ACL, resulting in kernel and user
space memory corruption.
Signed-off-by: NSven Wegener <sven.wegener@stealer.net>
Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Look for sudden changes in the first and second derivatives in order
to eliminate outlier changes to target_highest_slotid (which are
due to out-of-order RPC replies).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently, we see a lot of bouncing for the value of highest_used_slotid
due to the fact that slots are getting freed, instead of getting instantly
transmitted to the next waiting task.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We want to preserve the rpc_task priority for things like writebacks,
that may have differing levels of urgency.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

All it does is pass its arguments through to another function.  Let's
cut out the middleman...
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Privileged rpc calls are those that are run by the state recovery thread,
in cases where we're trying to recover the system after a server reboot
or a network partition. In those cases, we want to fence off all other
rpc calls (see nfs4_begin_drain_session()) so that they don't end up
using stateids or clientids that are in the process of being recovered.

Prior to this patch, we had to set up special callback functions in
order to declare an rpc call as being privileged.
By adding a new field to the sequence arguments, this patch simplifies
things considerably, and allows us to declare the rpc call as privileged
before it is run.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It is more important to preserve the task priority behaviour, which ensures
that things like reclaim writes take precedence over background and kupdate
writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Move all the sleep-and-exit cases into a single section of code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We shouldn't need to pass the 'cache_reply' parameter if we
initialise the sequence_args/sequence_res in the caller.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Nobody calls nfs4_setup_sequence or nfs41_setup_sequence without
also calling rpc_call_start() on success. This commit therefore
folds the rpc_call_start call into nfs41_setup_sequence().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

There is no point in using nfs4_setup_sequence or nfs4_sequence_done
in pure NFSv4.1 functions. We already know that those have sessions...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If the server requests a lower target_highest_slotid, then ensure
that we ping it with at least one RPC call containing an
appropriate SEQUENCE op. This ensures that the server won't need to
send a recall callback in order to shrink the slot table.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This means that we end up statically allocating 128 bytes for the
bitmap on each slot table.
For a server that supports 1MB write and read I/O sizes this means
that we can completely fill the maximum 1GB TCP send/receive
windows.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up. Gather NFSv4.1 slot definitions in fs/nfs/nfs4session.h.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv4.1 session management is getting complex enough to deserve
a separate file.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs4_wait_clnt_recover and nfs4_client_recover_expired_lease are both
generic state related functions. As such, they belong in nfs4state.c,
and not nfs4proc.c
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Coalesce nfs4_check_drain_bc_complete and nfs4_check_drain_fc_complete
into a single function that can be called when the slot table is known
to be empty, then change nfs4_callback_free_slot() and nfs4_free_slot()
to use it.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>