By sleeping on a new NFS Unlock-On-Close waitqueue, rpc tasks may wait for
a lock context's iocounter to reach zero.  The rpc waitqueue is only woken
when the open_context has the NFS_CONTEXT_UNLOCK flag set in order to
mitigate spurious wake-ups for any iocounter reaching zero.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Let's try to have it in a cacheline in nfs4_proc_pgio_rpc_prepare().
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Since commit 00bfa30a ("NFS: Create a common pgio_alloc and
pgio_release function"), nfs_pgarray_set() has only a single caller.  Let's
open code it.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Prevent a deadlock that can occur if we wait on allocations
that try to write back our pages.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Fixes: 00bfa30a ("NFS: Create a common pgio_alloc and pgio_release...")
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit a7d42ddb ("nfs: add mirroring
support to pgio layer") moved pg_cleanup out of the path when there was
non-sequental I/O that needed to be flushed.  The result is that for
layouts that have more than one layout segment per file, the pg_lseg is not
cleared, so we can end up hitting the WARN_ON_ONCE(req_start >= seg_end) in
pnfs_generic_pg_test since the pg_lseg will be pointing to that
previously-flushed layout segment.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Fixes: a7d42ddb ("nfs: add mirroring support to pgio layer")
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It now has only one field and is only used in one structure.
So replaced it in that structure by the field it contains.
Signed-off-by: NNeilBrown <neilb@suse.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

this field is not used in any important way and probably should
have been removed by

Commit: 8003d3c4 ("nfs4: treat lock owners as opaque values")

which removed the pid argument from nfs4_get_lock_state.

Except in unusual and uninteresting cases, two threads with the same
->tgid will have the same ->files pointer, so keeping them both
for comparison brings no benefit.
Acked-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

After using the offset of the swap entry as the key of the swap cache,
the page_index() becomes exactly same as page_file_index().  So the
page_file_index() is removed and the callers are changed to use
page_index() instead.

Link: http://lkml.kernel.org/r/1473270649-27229-2-git-send-email-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Copy will use this to set up a commit request for a generic range.  I
don't want to allocate a new pagecache entry for the file, so I needed
to change parts of the commit path to handle requests with a null
wb_page.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The use of wait_on_atomic_t() for waiting on I/O to complete before
unlocking allows us to git rid of the NFS_IO_INPROGRESS flag, and thus the
nfs_iocounter's flags member, and finally the nfs_iocounter altogether.
The count of I/O is moved to the lock context, and the counter
increment/decrement functions become simple enough to open-code.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
[Trond: Fix up conflict with existing function nfs_wait_atomic_killable()]
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If two processes share the same credentials and NFSv4 open stateid, then
allow them both to dirty the same page, even if their nfs_open_context
differs.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

In case we fail during setting things up for read/write IO, set
pg_error in IO descriptor and do the cleanup in nfs_pageio_add_request,
where we clean up all pages that are still hanging around on the IO
descriptor.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we fail to set up things before sending anything over wire,
we need to clean up the reqs that are still attached to the
IO descriptor.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

For ERESTARTSYS/EIO/EROFS/ENOSPC/E2BIG in layoutget, we
should just bail out instead of hiding the error and
retrying inband IO.

Change all the call sites to pop the error all the way up.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Jan Stancek reported that I wrecked things for him by fixing things for
Vladimir :/

His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which
should not be possible, however my previous patch made this possible by
unconditionally checking signal_pending().

We cannot use current->state as was done previously, because the
instruction after the store to that variable it can be changed.  We must
instead pass the initial state along and use that.

Fixes: 68985633 ("sched/wait: Fix signal handling in bit wait helpers")
Reported-by: NJan Stancek <jstancek@redhat.com>
Reported-by: NChris Mason <clm@fb.com>
Tested-by: NJan Stancek <jstancek@redhat.com>
Tested-by: NVladimir Murzin <vladimir.murzin@arm.com>
Tested-by: NChris Mason <clm@fb.com>
Reviewed-by: NPaul Turner <pjt@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: tglx@linutronix.de
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: hpa@zytor.com
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We really want sizeof(struct page *) instead. Otherwise we limit
maximum IO size to 64 pages rather than 512 pages on a 64bit system.

Fixes 2e11f829(nfs: cap request size to fit a kmalloced page array).

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Fixes: 2e11f829 ("nfs: cap request size to fit a kmalloced page array")
Signed-off-by: NTrond 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: NTrond Myklebust <trond.myklebust@primarydata.com>

Recoalescing does not affect whether or not we've already sent off
I/O, and doing so means that we end up sending a bunch of synchronous
for cases where we actually need to be using unstable writes.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the function exits early, then we must put those requests that were
not processed back onto the &mirror->pg_list so they can be cleaned up
by nfs_pgio_error().

Fixes: a7d42ddb ("nfs: add mirroring support to pgio layer")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Before rpc_run_task(), tk_pid is uninitiated as 0 always.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NYijing Wang <wangyijing@huawei.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This was only ever set to nfs_writeback_release_common(), a function
which is completely empty.  Let's just drop this function pointer and
simplify the code a bit.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

that's the bulk of filesystem drivers dealing with inodes of their own
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Let it return current nfs_pgio_mirror in use depending on pg_mirror_count.
For read, we always use pg_mirrors[0], so this effectively gives us freedom
to use pg_mirror_idx to track the actual mirror to read from through out the
IO stack.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <loghyr@primarydata.com>

so that we don't reset desc->pg_mirror_idx for read unnecessarily.
Remove WARN_ON_ONCE from __nfs_pageio_add_request to allow LD to
set pg_mirror_idx for read where pg_mirror_count is always 1.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <loghyr@primarydata.com>

This patch adds mirrored write support to the pgio layer. The default
is to use one mirror, but pgio callers may define callbacks to change
this to any value up to the (arbitrarily selected) limit of 16.

The basic idea is to break out members of nfs_pageio_descriptor that cannot
be shared between mirrored DSes and put them in a new structure.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>

Add a new operation to nfs_pageio_ops that is called on nfs_pageio_complete.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>

so that flexfile layout client can pass in DS credential instead of
using user cred, which will be done in the next patch.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NTom Haynes <Thomas.Haynes@primarydata.com>

Signed-off-by: NTom Haynes <loghyr@primarydata.com>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

Recent work in the pgio layer made it possible for there to be more than one
request per page. This caused a subtle change in commit behavior, because
write.c:nfs_commit_unstable_pages compares the number of *pages* waiting for
writeback against the number of requests on a commit list to choose when to
send a COMMIT in a non-blocking flush.

This is probably hard to hit in normal operation - you have to be using
rsize/wsize < PAGE_SIZE, or pnfs with lots of boundaries that are not page
aligned to have a noticeable change in behavior.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It is OK for pageused == pagecount in the loop, as long as we don't add
another entry to the *pages array. Move the test so that it only triggers
in that case.
Reported-by: NSteve Dickson <SteveD@redhat.com>
Fixes: bba5c188 (nfs: disallow duplicate pages in pgio page vectors)
Cc: Weston Andros Adamson <dros@primarydata.com>
Cc: stable@vger.kernel.org # 3.16.x
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

SteveD reports the following Oops:
 RIP: 0010:[<ffffffffa053461d>]  [<ffffffffa053461d>] __put_nfs_open_context+0x1d/0x100 [nfs]
 RSP: 0018:ffff880fed687b90  EFLAGS: 00010286
 RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000006
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
 RBP: ffff880fed687bc0 R08: 0000000000000092 R09: 000000000000047a
 R10: 0000000000000000 R11: ffff880fed6878d6 R12: ffff880fed687d20
 R13: ffff880fed687d20 R14: 0000000000000070 R15: ffffea000aa33ec0
 FS:  00007fce290f0740(0000) GS:ffff8807ffc60000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000070 CR3: 00000007f2e79000 CR4: 00000000000007e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  0000000000000000 ffff880036c5e510 ffff880fed687d20 ffff880fed687d20
  ffff880036c5e200 ffffea000aa33ec0 ffff880fed687bd0 ffffffffa0534710
  ffff880fed687be8 ffffffffa053d5f0 ffff880036c5e200 ffff880fed687c08
 Call Trace:
  [<ffffffffa0534710>] put_nfs_open_context+0x10/0x20 [nfs]
  [<ffffffffa053d5f0>] nfs_pgio_data_destroy+0x20/0x40 [nfs]
  [<ffffffffa053d672>] nfs_pgio_error+0x22/0x40 [nfs]
  [<ffffffffa053d8f4>] nfs_generic_pgio+0x74/0x2e0 [nfs]
  [<ffffffffa06b18c3>] pnfs_generic_pg_writepages+0x63/0x210 [nfsv4]
  [<ffffffffa053d579>] nfs_pageio_doio+0x19/0x50 [nfs]
  [<ffffffffa053eb84>] nfs_pageio_complete+0x24/0x30 [nfs]
  [<ffffffffa053cb25>] nfs_direct_write_schedule_iovec+0x115/0x1f0 [nfs]
  [<ffffffffa053675f>] ? nfs_get_lock_context+0x4f/0x120 [nfs]
  [<ffffffffa053d252>] nfs_file_direct_write+0x262/0x420 [nfs]
  [<ffffffffa0532d91>] nfs_file_write+0x131/0x1d0 [nfs]
  [<ffffffffa0532c60>] ? nfs_need_sync_write.isra.17+0x40/0x40 [nfs]
  [<ffffffff812127b8>] do_io_submit+0x3b8/0x840
  [<ffffffff81212c50>] SyS_io_submit+0x10/0x20
  [<ffffffff81610f29>] system_call_fastpath+0x16/0x1b

This is due to the calls to nfs_pgio_error() in nfs_generic_pgio(), which
happen before the nfs_pgio_header's open context is referenced in
nfs_pgio_rpcsetup().
Reported-by: NSteve Dickson <SteveD@redhat.com>
Cc: stable@vger.kernel.org # 3.16.x
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

pNFS servers may return arbitrarily large layouts.  Trim back the I/O size
to one that we can at least allocate the page array for.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If a SIGKILL is sent to a task waiting in __nfs_iocounter_wait,
it will busy-wait or soft lockup in its while loop.
nfs_wait_bit_killable won't sleep, and the loop won't exit on
the error return.

Stop the busy-wait by breaking out of the loop when
nfs_wait_bit_killable returns an error.
Signed-off-by: NDavid Jeffery <djeffery@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Commit 6094f838
"nfs: allow coalescing of subpage requests" got rid of the requirement
that requests cover whole pages, but it made some incorrect assumptions.

It turns out that callers of this interface can map adjacent requests
(by file position as seen by req_offset + req->wb_bytes) to different pages,
even when they could share a page. An example is the direct I/O interface -
iov_iter_get_pages_alloc may return one segment with a partial page filled
and the next segment (which is adjacent in the file position) starts with a
new page.
Reported-by: NToralf Förster <toralf.foerster@gmx.de>
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Adjacent requests that share the same page are allowed, but should only
use one entry in the page vector. This avoids overruning the page
vector - it is sized based on how many bytes there are, not by
request count.

This fixes issues that manifest as "Redzone overwritten" bugs (the
vector overrun) and hangs waiting on page read / write, as it waits on
the same page more than once.

This also adds bounds checking to the page vector with a graceful failure
(WARN_ON_ONCE and pgio error returned to application).
Reported-by: NToralf Förster <toralf.foerster@gmx.de>
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>