Commit Graph

346 Commits

Author SHA1 Message Date
Linus Torvalds d1e1cda862 NFS client updates for Linux 3.16
Highlights include:
 
 - Massive cleanup of the NFS read/write code by Anna and Dros
 - Support multiple NFS read/write requests per page in order to deal with
   non-page aligned pNFS striping. Also cleans up the r/wsize < page size
   code nicely.
 - stable fix for ensuring inode is declared uptodate only after all the
   attributes have been checked.
 - stable fix for a kernel Oops when remounting
 - NFS over RDMA client fixes
 - move the pNFS files layout driver into its own subdirectory
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Merge tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

   - massive cleanup of the NFS read/write code by Anna and Dros
   - support multiple NFS read/write requests per page in order to deal
     with non-page aligned pNFS striping.  Also cleans up the r/wsize <
     page size code nicely.
   - stable fix for ensuring inode is declared uptodate only after all
     the attributes have been checked.
   - stable fix for a kernel Oops when remounting
   - NFS over RDMA client fixes
   - move the pNFS files layout driver into its own subdirectory"

* tag 'nfs-for-3.16-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (79 commits)
  NFS: populate ->net in mount data when remounting
  pnfs: fix lockup caused by pnfs_generic_pg_test
  NFSv4.1: Fix typo in dprintk
  NFSv4.1: Comment is now wrong and redundant to code
  NFS: Use raw_write_seqcount_begin/end int nfs4_reclaim_open_state
  xprtrdma: Disconnect on registration failure
  xprtrdma: Remove BUG_ON() call sites
  xprtrdma: Avoid deadlock when credit window is reset
  SUNRPC: Move congestion window constants to header file
  xprtrdma: Reset connection timeout after successful reconnect
  xprtrdma: Use macros for reconnection timeout constants
  xprtrdma: Allocate missing pagelist
  xprtrdma: Remove Tavor MTU setting
  xprtrdma: Ensure ia->ri_id->qp is not NULL when reconnecting
  xprtrdma: Reduce the number of hardway buffer allocations
  xprtrdma: Limit work done by completion handler
  xprtrmda: Reduce calls to ib_poll_cq() in completion handlers
  xprtrmda: Reduce lock contention in completion handlers
  xprtrdma: Split the completion queue
  xprtrdma: Make rpcrdma_ep_destroy() return void
  ...
2014-06-10 15:02:42 -07:00
Weston Andros Adamson d72ddcbab6 nfs: page group support in nfs_mark_uptodate
Change how nfs_mark_uptodate checks to see if writes cover a whole page.

This patch should have no effect yet since all page groups currently
have one request, but will come into play when pg_test functions are
modified to split pages into sub-page regions.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:46 -04:00
Weston Andros Adamson 20633f042f nfs: page group syncing in write path
Operations that modify state for a whole page must be syncronized across
all requests within a page group. In the write path, this is calling
end_page_writeback and removing the head request from an inode.
Both of these operations should not be called until all requests
in a page group have reached the point where they would call them.

This patch should have no effect yet since all page groups currently
have one request, but will come into play when pg_test functions are
modified to split pages into sub-page regions.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:45 -04:00
Weston Andros Adamson 2bfc6e566d nfs: add support for multiple nfs reqs per page
Add "page groups" - a circular list of nfs requests (struct nfs_page)
that all reference the same page. This gives nfs read and write paths
the ability to account for sub-page regions independently.  This
somewhat follows the design of struct buffer_head's sub-page
accounting.

Only "head" requests are ever added/removed from the inode list in
the buffered write path. "head" and "sub" requests are treated the
same through the read path and the rest of the write/commit path.
Requests are given an extra reference across the life of the list.

Page groups are never rejoined after being split. If the read/write
request fails and the client falls back to another path (ie revert
to MDS in PNFS case), the already split requests are pushed through
the recoalescing code again, which may split them further and then
coalesce them into properly sized requests on the wire. Fragmentation
shouldn't be a problem with the current design, because we flush all
requests in page group when a non-contiguous request is added, so
the only time resplitting should occur is on a resend of a read or
write.

This patch lays the groundwork for sub-page splitting, but does not
actually do any splitting. For now all page groups have one request
as pg_test functions don't yet split pages. There are several related
patches that are needed support multiple requests per page group.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:44 -04:00
Weston Andros Adamson 8c8f1ac109 nfs: remove unused arg from nfs_create_request
@inode is passed but not used.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:43 -04:00
Anna Schumaker 41d8d5b7a5 NFS: Create a common nfs_pageio_ops struct
At this point the read and write structures look identical, so combine
them into something shared by both.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:41 -04:00
Anna Schumaker cf485fcd68 NFS: Create a common generic_pg_pgios()
What we have here is two functions that look identical.  Let's share
some more code!

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:41 -04:00
Anna Schumaker c3766276f2 NFS: Create a common multiple_pgios() function
Once again, these two functions look identical in the read and write
case.  Time to combine them together!

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:40 -04:00
Anna Schumaker 1ed26f3300 NFS: Create a common initiate_pgio() function
Most of this code is the same for both the read and write paths, so
combine everything and use the rw_ops when necessary.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-29 11:11:40 -04:00
Anna Schumaker ef2c488c07 NFS: Create a generic_pgio function
These functions are almost identical on both the read and write side.
FLUSH_COND_STABLE will never be set for the read path, so leaving it in
the generic code won't hurt anything.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:41:12 -04:00
Anna Schumaker 844c9e691d NFS: Create a common pgio_error function
At this point, the read and write versions of this function look
identical so both should use the same function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:41:04 -04:00
Anna Schumaker ce59515c14 NFS: Create a common rpcsetup function for reads and writes
Write adds a little bit of code dealing with flush flags, but since
"how" will always be 0 when reading we can share the code.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:40:56 -04:00
Anna Schumaker 6f92fa4581 NFS: Create a common rpc_call_ops struct
The read and write paths set up this struct in exactly the same way, so
create a single shared struct.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:40:43 -04:00
Anna Schumaker 0eecb2145c NFS: Create a common nfs_pgio_result_common function
Combining these functions will let me make a single nfs_rw_common_ops
struct (see the next patch).

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:40:36 -04:00
Anna Schumaker a4cdda5911 NFS: Create a common pgio_rpc_prepare function
The read and write paths do exactly the same thing for the rpc_prepare
rpc_op.  This patch combines them together into a single function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:40:28 -04:00
Anna Schumaker 4a0de55c56 NFS: Create a common rw_header_alloc and rw_header_free function
I create a new struct nfs_rw_ops to decide the differences between reads
and writes.  This struct will be set when initializing a new
nfs_pgio_descriptor, and then passed on to the nfs_rw_header when a new
header is allocated.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:40:04 -04:00
Anna Schumaker 00bfa30abe NFS: Create a common pgio_alloc and pgio_release function
These functions are identical for the read and write paths so they can
be combined.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:39:55 -04:00
Anna Schumaker f79d06f544 NFS: Move the write verifier into the nfs_pgio_header
The header had a pointer to the verifier that was set from the old write
data struct.  We don't need to keep the pointer around now that we have
shared structures.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:39:38 -04:00
Anna Schumaker c0752cdfbb NFS: Create a common read and write header struct
The only difference is the write verifier field, but we can keep that
for a little bit longer.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:12:55 -04:00
Anna Schumaker 9c7e1b3d50 NFS: Create a common read and write data struct
At this point, the only difference between nfs_read_data and
nfs_write_data is the write verifier.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:12:47 -04:00
Anna Schumaker 9137bdf3d2 NFS: Create a common results structure for reads and writes
Reads and writes have very similar results.  This patch combines the two
structs together with comments to show where the differing fields are
used.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:12:43 -04:00
Anna Schumaker 3c6b899c49 NFS: Create a common argument structure for reads and writes
Reads and writes have very similar arguments.  This patch combines them
together and documents the few fields used only by write.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 18:12:02 -04:00
Christoph Hellwig a20c93e316 nfs: remove ->write_pageio_init from rpc ops
The write_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_write based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-05-28 17:48:38 -04:00
Peter Zijlstra 4e857c58ef arch: Mass conversion of smp_mb__*()
Mostly scripted conversion of the smp_mb__* barriers.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18 14:20:48 +02:00
Trond Myklebust 1f2edbe3fe NFS: Don't ignore suid/sgid bit changes after a successful write
If we suspect that the server may have cleared the suid/sgid bit,
then mark the inode for revalidation.

Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-04-15 23:24:43 -04:00
Jeff Layton 4db72b40fd nfs: add memory barriers around NFS_INO_INVALID_DATA and NFS_INO_INVALIDATING
If the setting of NFS_INO_INVALIDATING gets reordered to before the
clearing of NFS_INO_INVALID_DATA, then another task may hit a race
window where both appear to be clear, even though the inode's pages are
still in need of invalidation. Fix this by adding the appropriate memory
barriers.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-28 14:48:18 -05:00
Jeff Layton d529ef83c3 NFS: fix the handling of NFS_INO_INVALID_DATA flag in nfs_revalidate_mapping
There is a possible race in how the nfs_invalidate_mapping function is
handled.  Currently, we go and invalidate the pages in the file and then
clear NFS_INO_INVALID_DATA.

The problem is that it's possible for a stale page to creep into the
mapping after the page was invalidated (i.e., via readahead). If another
writer comes along and sets the flag after that happens but before
invalidate_inode_pages2 returns then we could clear the flag
without the cache having been properly invalidated.

So, we must clear the flag first and then invalidate the pages. Doing
this however, opens another race:

It's possible to have two concurrent read() calls that end up in
nfs_revalidate_mapping at the same time. The first one clears the
NFS_INO_INVALID_DATA flag and then goes to call nfs_invalidate_mapping.

Just before calling that though, the other task races in, checks the
flag and finds it cleared. At that point, it trusts that the mapping is
good and gets the lock on the page, allowing the read() to be satisfied
from the cache even though the data is no longer valid.

These effects are easily manifested by running diotest3 from the LTP
test suite on NFS. That program does a series of DIO writes and buffered
reads. The operations are serialized and page-aligned but the existing
code fails the test since it occasionally allows a read to come out of
the cache incorrectly. While mixing direct and buffered I/O isn't
recommended, I believe it's possible to hit this in other ways that just
use buffered I/O, though that situation is much harder to reproduce.

The problem is that the checking/clearing of that flag and the
invalidation of the mapping really need to be atomic. Fix this by
serializing concurrent invalidations with a bitlock.

At the same time, we also need to allow other places that check
NFS_INO_INVALID_DATA to check whether we might be in the middle of
invalidating the file, so fix up a couple of places that do that
to look for the new NFS_INO_INVALIDATING flag.

Doing this requires us to be careful not to set the bitlock
unnecessarily, so this code only does that if it believes it will
be doing an invalidation.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-27 15:35:56 -05:00
Scott Mayhew 263b4509ec nfs: always make sure page is up-to-date before extending a write to cover the entire page
We should always make sure the cached page is up-to-date when we're
determining whether we can extend a write to cover the full page -- even
if we've received a write delegation from the server.

Commit c7559663 added logic to skip this check if we have a write
delegation, which can lead to data corruption such as the following
scenario if client B receives a write delegation from the NFS server:

Client A:
    # echo 123456789 > /mnt/file

Client B:
    # echo abcdefghi >> /mnt/file
    # cat /mnt/file
    0�D0�abcdefghi

Just because we hold a write delegation doesn't mean that we've read in
the entire page contents.

Cc: <stable@vger.kernel.org> # v3.11+
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-17 15:37:15 -05:00
Niels de Vos 1e8968c5b0 NFS: dprintk() should not print negative fileids and inode numbers
A fileid in NFS is a uint64. There are some occurrences where dprintk()
outputs a signed fileid. This leads to confusion and more difficult to
read debugging (negative fileids matching positive inode numbers).

Signed-off-by: Niels de Vos <ndevos@redhat.com>
CC: Santosh Pradhan <spradhan@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-01-05 15:51:23 -05:00
Al Viro 6de1472f1a nfs: use %p[dD] instead of open-coded (and often racy) equivalents
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:50 -04:00
Trond Myklebust 0f1d260550 NFS: Don't check lock owner compatibility in writes unless file is locked
If we're doing buffered writes, and there is no file locking involved,
then we don't have to worry about whether or not the lock owner information
is identical.
By relaxing this check, we ensure that fork()ed child processes can write
to a page without having to first sync dirty data that was written
by the parent to disk.

Reported-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Quentin Barnes <qbarnes@gmail.com>
2013-09-05 18:11:42 -04:00
Weston Andros Adamson 8c21c62c44 nfs4.1: Add SP4_MACH_CRED write and commit support
WRITE and COMMIT can use the machine credential.

If WRITE is supported and COMMIT is not, make all (mach cred) writes FILE_SYNC4.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-05 10:50:45 -04:00
NeilBrown ef1820f9be NFSv4: Don't try to recover NFSv4 locks when they are lost.
When an NFSv4 client loses contact with the server it can lose any
locks that it holds.

Currently when it reconnects to the server it simply tries to reclaim
those locks.  This might succeed even though some other client has
held and released a lock in the mean time.  So the first client might
think the file is unchanged, but it isn't.  This isn't good.

If, when recovery happens, the locks cannot be claimed because some
other client still holds the lock, then we get a message in the kernel
logs, but the client can still write.  So two clients can both think
they have a lock and can both write at the same time.  This is equally
not good.

There was a patch a while ago
  http://comments.gmane.org/gmane.linux.nfs/41917

which tried to address some of this, but it didn't seem to go
anywhere.  That patch would also send a signal to the process.  That
might be useful but for now this patch just causes writes to fail.

For NFSv4 (unlike v2/v3) there is a strong link between the lock and
the write request so we can fairly easily fail any IO of the lock is
gone.  While some applications might not expect this, it is still
safer than allowing the write to succeed.

Because this is a fairly big change in behaviour a module parameter,
"recover_locks", is introduced which defaults to true (the current
behaviour) but can be set to "false" to tell the client not to try to
recover things that were lost.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-04 12:26:32 -04:00
Andy Adamson dc24826bfc NFS avoid expired credential keys for buffered writes
We must avoid buffering a WRITE that is using a credential key (e.g. a GSS
context key) that is about to expire or has expired.  We currently will
paint ourselves into a corner by returning success to the applciation
for such a buffered WRITE, only to discover that we do not have permission when
we attempt to flush the WRITE (and potentially associated COMMIT) to disk.

Use the RPC layer credential key timeout and expire routines which use a
a watermark, gss_key_expire_timeo. We test the key in nfs_file_write.

If a WRITE is using a credential with a key that will expire within
watermark seconds, flush the inode in nfs_write_end and send only
NFS_FILE_SYNC WRITEs by adding nfs_ctx_key_to_expire to nfs_need_sync_write.
Note that this results in single page NFS_FILE_SYNC WRITEs.

Signed-off-by: Andy Adamson <andros@netapp.com>
[Trond: removed a pr_warn_ratelimited() for now]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-09-03 15:25:09 -04:00
Trond Myklebust f4ce1299b3 NFS: Add event tracing for generic NFS events
Add tracepoints for inode attribute updates, attribute revalidation,
writeback start/end fsync start/end, attribute change start/end,
permission check start/end.

The intention is to enable performance tracing using 'perf'as well as
improving debugging.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-22 08:58:17 -04:00
Scott Mayhew c7559663e4 NFS: Allow nfs_updatepage to extend a write under additional circumstances
Currently nfs_updatepage allows a write to be extended to cover a full
page only if we don't have a byte range lock lock on the file... but if
we have a write delegation on the file or if we have the whole file
locked for writing then we should be allowed to extend the write as
well.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
[Trond: fix up call to nfs_have_delegation()]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-07-09 19:32:50 -04:00
Trond Myklebust c58c844187 NFS: Don't accept more reads/writes if the open context recovery failed
If the state recovery failed, we want to ensure that the application
doesn't try to use the same file descriptor for more reads or writes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-03-25 12:04:10 -04:00
Trond Myklebust 6db6dd7d3f NFS: Ensure that we free the rpc_task after read and write cleanups are done
This patch ensures that we free the rpc_task after the cleanup callbacks
are done in order to avoid a deadlock problem that can be triggered if
the callback needs to wait for another workqueue item to complete.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Weston Andros Adamson <dros@netapp.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org [>= 3.5]
2013-01-04 12:59:10 -05:00
David Howells 8c209ce721 NFS: nfs_migrate_page() does not wait for FS-Cache to finish with a page
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: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
2012-12-20 22:12:03 +00:00
Trond Myklebust ada8e20d04 NFS: Don't use SetPageError in the NFS writeback code
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 7b281ee026 (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: Neil Brown <neilb@suse.de>
Tested-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org [3.6+]
2012-12-15 17:12:14 -05:00
Trond Myklebust 7ce0171d4f Merge branch 'bugfixes' into nfs-for-next 2012-12-11 09:16:26 -05:00
Jeff Layton 81d9bce530 nfs: don't extend writes to cover entire page if pagecache is invalid
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 8d197a568. 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: Jian Li <jiali@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-12-11 09:14:51 -05:00
Yanchuan Nian 4c10021008 nfs: Fix wrong slab cache in nfs_commit_mempool
The slab cache in nfs_commit_mempool is wrong, and I think it is just a slip.
I tested it on a x86-32 machine, the size of nfs_write_header is 544, and
the size of nfs_commit_data is 408, so it works fine. It is also true that
sizeof(struct nfs_write_header) > sizeof(struct nfs_commit_data) on other
platforms in my opinoin. Just fix it.

Signed-off-by: Yanchuan Nian <ycnian@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-25 11:59:33 -05:00
Trond Myklebust deed85e760 NFS: Remove BUG_ON() calls from the generic writeback code
...and ensure that we set the return value for nfs_page_async_flush()
to zero! (Reported-by: Dros Adamson)

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-11-04 14:43:39 -05:00
Trond Myklebust 05990d1bf2 NFS: Fix fdatasync/fsync() when confronted with a server reboot
If the server reboots before it can commit the unstable writes to disk,
then nfs_commit_release_pages() will detect this when it compares the
verifier returned by COMMIT to the one returned by WRITE. When this
happens, the client needs to resend those writes in order to guarantee
that they make it to stable storage.

This patch adds a signalling mechanism to notify fsync() that it
needs to retry all writes before it can exit.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:05 -04:00
Trond Myklebust 2a369153c8 NFS: Clean up helper function nfs4_select_rw_stateid()
We want to be able to pass on the information that the page was not
dirtied under a lock. Instead of adding a flag parameter, do this
by passing a pointer to a 'struct nfs_lock_owner' that may be NULL.

Also reuse this structure in struct nfs_lock_context to carry the
fl_owner_t and pid_t.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-09-28 16:03:04 -04:00
Jeff Layton 3dd4765fce nfs: tear down caches in nfs_init_writepagecache when allocation fails
...and ensure that we tear down the nfs_commit_data cache too when
unloading the module.

Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2012-08-02 17:36:07 -04:00
Linus Torvalds ac694dbdbc Merge branch 'akpm' (Andrew's patch-bomb)
Merge Andrew's second set of patches:
 - MM
 - a few random fixes
 - a couple of RTC leftovers

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits)
  rtc/rtc-88pm80x: remove unneed devm_kfree
  rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails
  mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
  tmpfs: distribute interleave better across nodes
  mm: remove redundant initialization
  mm: warn if pg_data_t isn't initialized with zero
  mips: zero out pg_data_t when it's allocated
  memcg: gix memory accounting scalability in shrink_page_list
  mm/sparse: remove index_init_lock
  mm/sparse: more checks on mem_section number
  mm/sparse: optimize sparse_index_alloc
  memcg: add mem_cgroup_from_css() helper
  memcg: further prevent OOM with too many dirty pages
  memcg: prevent OOM with too many dirty pages
  mm: mmu_notifier: fix freed page still mapped in secondary MMU
  mm: memcg: only check anon swapin page charges for swap cache
  mm: memcg: only check swap cache pages for repeated charging
  mm: memcg: split swapin charge function into private and public part
  mm: memcg: remove needless !mm fixup to init_mm when charging
  mm: memcg: remove unneeded shmem charge type
  ...
2012-07-31 19:25:39 -07:00
Mel Gorman 192e501b04 nfs: prevent page allocator recursions with swap over NFS.
GFP_NOFS is _more_ permissive than GFP_NOIO in that it will initiate IO,
just not of any filesystem data.

The problem is that previously NOFS was correct because that avoids
recursion into the NFS code.  With swap-over-NFS, it is no longer correct
as swap IO can lead to this recursion.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:48 -07:00
Mel Gorman 29418aa4bd nfs: disable data cache revalidation for swapfiles
The VM does not like PG_private set on PG_swapcache pages.  As suggested
by Trond in http://lkml.org/lkml/2006/8/25/348, this patch disables NFS
data cache revalidation on swap files.  as it does not make sense to have
other clients change the file while it is being used as swap.  This avoids
setting PG_private on swap pages, since there ought to be no further races
with invalidate_inode_pages2() to deal with.

Since we cannot set PG_private we cannot use page->private which is
already used by PG_swapcache pages to store the nfs_page.  Thus augment
the new nfs_page_find_request logic.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 18:42:47 -07:00