fail-nth interface is only created in /proc/self/task/<current-tid>/.
This change also adds it in /proc/<pid>/.

This makes shell based tool a bit simpler.

	$ bash -c "builtin echo 100 > /proc/self/fail-nth && exec ls /"

Link: http://lkml.kernel.org/r/1491490561-10485-6-git-send-email-akinobu.mita@gmail.comSigned-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The fail-nth file is created with 0666 and the access is permitted if
and only if the task is current.

This file is owned by the currnet user.  So we can create it with 0644
and allow the owner to write it.  This enables to watch the status of
task->fail_nth from another processes.

[akinobu.mita@gmail.com: don't convert unsigned type value as signed int]
  Link: http://lkml.kernel.org/r/1492444483-9239-1-git-send-email-akinobu.mita@gmail.com
[akinobu.mita@gmail.com: avoid unwanted data race to task->fail_nth]
  Link: http://lkml.kernel.org/r/1499962492-8931-1-git-send-email-akinobu.mita@gmail.com
Link: http://lkml.kernel.org/r/1491490561-10485-5-git-send-email-akinobu.mita@gmail.comSigned-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Acked-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The read interface for fail-nth looks a bit odd.  Read from this file
returns "NYYYY..." or "YYYYY..." (this makes me surprise when cat this
file).  Because there is no EOF condition.  The first character
indicates current->fail_nth is zero or not, and then current->fail_nth
is reset to zero.

Just returning task->fail_nth value is more natural to understand.

Link: http://lkml.kernel.org/r/1491490561-10485-4-git-send-email-akinobu.mita@gmail.comSigned-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The value written to fail-nth file is parsed as 0-based.  Parsing as
one-based is more natural to understand and it enables to cancel the
previous setup by simply writing '0'.

This change also converts task->fail_nth from signed to unsigned int.

Link: http://lkml.kernel.org/r/1491490561-10485-3-git-send-email-akinobu.mita@gmail.comSigned-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Automatically detect the number base to use when writing to fail-nth
file instead of always parsing as a decimal number.

Link: http://lkml.kernel.org/r/1491490561-10485-2-git-send-email-akinobu.mita@gmail.comSigned-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With blk_status_t conversion (that are now present in master),
bio_readpage_error() may return 1 as now ->submit_bio_hook() may not set
%ret if it runs without problems.

This fixes that unexpected return value by changing
btrfs_check_repairable() to return a bool instead of updating %ret, and
patch is applicable to both codebases with and without blk_status_t.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

As the function uses the non-failing bio allocation, we can remove error
handling from the callers as well.
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We've started using cloned bios more in 4.13, there are some specifics
regarding the iteration.  Filipe found [1] that the raid56 iterated a
cloned bio using bio_for_each_segment_all, which is incorrect. The
cloned bios have wrong bi_vcnt and this could lead to silent
corruptions.  This patch adds assertions to all remaining
bio_for_each_segment_all cases.

[1] https://patchwork.kernel.org/patch/9838535/Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

In the iomap implementations of SEEK_HOLE and SEEK_DATA, make sure we
return -ENXIO for negative offsets.
Inspired-by: NMateusz S <muttdini@gmail.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

This reverts commit 50e0bdbe.

The new XFS_QMOPT_NOLOCK isn't used at all, and conditional locking based
on a flag is always the wrong thing to do - we should be having helpers
that can be called without the lock instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The comment mentioned the wrong lock.  Also add an ASSERT to assert
this locking precondition.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

"perf lock" shows fairly heavy contention for the bit waitqueue locks
when doing an I/O heavy workload.
Use a bit to tell whether or not there has been contention for a lock
so that we can optimise away the bit waitqueue options in those cases.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This support for opening files on NFS by file handle, both through the
open_by_handle syscall, and for re-exporting NFS (for example using a
different version).  The support is very basic for now, as each open by
handle will have to do an NFSv4 open operation on the wire.  In the
future this will hopefully be mitigated by an open file cache, as well
as various optimizations in NFS for this specific case.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
[hch: incorporated various changes, resplit the patches, new changelog]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This will be needed in order to implement the get_parent export op
for nfsd.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

This helper will allow to find an existing NFS inode by the file handle
and fattr.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
[hch: split from a larger patch]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

It's a trival change but follows knfsd export document that asks
for d_splice_alias during lookup.
Signed-off-by: NPeng Tao <tao.peng@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Return size of COPY is u64 but it was assigned to an "int" status.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Transparent State Migration copies a client's lease state from the
server where a filesystem used to reside to the server where it now
resides. When an NFSv4.1 client first contacts that destination
server, it uses EXCHANGE_ID to detect trunking relationships.

The lease that was copied there is returned to that client, but the
destination server sets EXCHGID4_FLAG_CONFIRMED_R when replying to
the client. This is because the lease was confirmed on the source
server (before it was copied).

When CONFIRMED_R is set, the client throws away the sequence ID
returned by the server. During a Transparent State Migration, however
there's no other way for the client to know what sequence ID to use
with a lease that's been migrated.

Therefore, the client must save and use the contrived slot sequence
value returned by the destination server even when CONFIRMED_R is
set.

Note that some servers always return a seqid of 1 after a migration.
Reported-by: NXuan Qi <xuan.qi@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NXuan Qi <xuan.qi@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Transparent State Migration copies a client's lease state from the
server where a filesystem used to reside to the server where it now
resides. When an NFSv4.1 client first contacts that destination
server, it uses EXCHANGE_ID to detect trunking relationships.

The lease that was copied there is returned to that client, but the
destination server sets EXCHGID4_FLAG_CONFIRMED_R when replying to
the client. This is because the lease was confirmed on the source
server (before it was copied).

Normally, when CONFIRMED_R is set, a client purges the lease and
creates a new one. However, that throws away the entire benefit of
Transparent State Migration.

Therefore, the client must not purge that lease when it is possible
that Transparent State Migration has occurred.
Reported-by: NXuan Qi <xuan.qi@oracle.com>
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NXuan Qi <xuan.qi@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If an NFS server returns a filehandle that we have previously
seen, and reports a different type, then nfs_refresh_inode()
will log a warning and return an error.

nfs_fhget() does not check for this error and may return an
inode with a different type than the one that the server
reported.

This is likely to cause confusion, and is one way that
->open_context() could return a directory inode as discussed
in the previous patch.

So if nfs_refresh_inode() returns and error, return that error
from nfs_fhget() to avoid the confusion propagating.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

A confused server could return a filehandle for an
NFSv4 OPEN request, which it previously returned for a directory.
So the inode returned by  ->open_context() in nfs_atomic_open()
could conceivably be a directory inode.

This has particular implications for the call to
nfs_file_set_open_context() in nfs_finish_open().
If that is called on a directory inode, then the nfs_open_context
that gets stored in the filp->private_data will be linked to
nfs_inode->open_files.

When the directory is closed, nfs_closedir() will (ultimately)
free the ->private_data, but not unlink it from nfs_inode->open_files
(because it doesn't expect an nfs_open_context there).

Subsequently the memory could get used for something else and eventually
if the ->open_files list is walked, the walker will fall off the end and
crash.

So: change nfs_finish_open() to only call nfs_file_set_open_context()
for regular-file inodes.

This failure mode has been seen in a production setting (unknown NFS
server implementation).  The kernel was v3.0 and the specific sequence
seen would not affect more recent kernels, but I think a risk is still
present, and caution is wise.
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Since commit bafc9b75 ("vfs: More precise tests in d_invalidate")
in v3.18, a return of '0' from ->d_revalidate() will cause the dentry
to be invalidated even if it has filesystems mounted on or it or on a
descendant.  The mounted filesystem is unmounted.

This means we need to be careful not to return 0 unless the directory
referred to truly is invalid.  So -ESTALE or -ENOENT should invalidate
the directory.  Other errors such a -EPERM or -ERESTARTSYS should be
returned from ->d_revalidate() so they are propagated to the caller.

A particular problem can be demonstrated by:

1/ mount an NFS filesystem using NFSv3 on /mnt
2/ mount any other filesystem on /mnt/foo
3/ ls /mnt/foo
4/ turn off network, or otherwise make the server unable to respond
5/ ls /mnt/foo &
6/ cat /proc/$!/stack # note that nfs_lookup_revalidate is in the call stack
7/ kill -9 $! # this results in -ERESTARTSYS being returned
8/ observe that /mnt/foo has been unmounted.

This patch changes nfs_lookup_revalidate() to only treat
  -ESTALE from nfs_lookup_verify_inode() and
  -ESTALE or -ENOENT from ->lookup()
as indicating an invalid inode.  Other errors are returned.

Also nfs_check_inode_attributes() is changed to return -ESTALE rather
than -EIO.  This is consistent with the error returned in similar
circumstances from nfs_update_inode().

As this bug allows any user to unmount a filesystem mounted on an NFS
filesystem, this fix is suitable for stable kernels.

Fixes: bafc9b75 ("vfs: More precise tests in d_invalidate")
Cc: stable@vger.kernel.org (v3.18+)
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Upon receiving a stateid error such as BAD_STATEID, the client
should retry the operation against the MDS before deciding to
do stateid recovery.

Previously, the code would initiate state recovery and it could
lead to a race in a state manager that could chose an incorrect
recovery method which would lead to the EIO failure for the
application.
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit fabbbee0 "PNFS fix fallback to MDS if got error on
commit to DS" moved the pnfs_set_lo_fail() to unhandled errors
which was not correct and lead to a kernel oops on umount.

Instead, fix the original EACCESS on commit to DS error by
getting the new layout and re-doing the IO.

Fixes: fabbbee0 ("PNFS fix fallback to MDS if got error on commit to DS")
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Cc: stable@vger.kernel.org # v4.12
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Static checkers have gotten clever enough to complain that "id_long" is
uninitialized on the failure path.  It's harmless, but simple to fix.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

nfs_show_stats() was incorrectly reading statistics for bytes when printing that
for fsc. It caused files like /proc/self/mountstats to report incorrect fsc
statistics for NFS mounts.
Signed-off-by: NTuo Chen Peng <tpeng@nvidia.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Commit 8ef9b0b9 open-coded nfs_pgarray_set(), and left out the
initialization of the nfs_page_array's npages.  This mistake didn't show up
until testing with block layouts, and there shows that all pNFS reads
return -EIO.

Fixes: 8ef9b0b9 ("NFS: move nfs_pgarray_set() to open code")
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org # 4.12
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Now that the writes will schedule a commit on their own, we don't
need nfs_write_inode() to schedule one if there are outstanding
writes, and we're being called in non-blocking mode.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the page cache is being flushed, then we want to ensure that we
do start a commit once the pages are done being flushed.
If we just wait until all I/O is done to that file, we can end up
livelocking until the balance_dirty_pages() mechanism puts its
foot down and forces I/O to stop.
So instead we do more or less the same thing that O_DIRECT does,
and set up a counter to tell us when the flush is done,
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Remove the 'layout_private' fields that were only used by the pNFS OSD
layout driver.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

An interrupted rename will leave the old dentry behind if the rename
succeeds.  Fix this by forcing a lookup the next time through
->d_revalidate.

A previous attempt at solving this problem took the approach to complete
the work of the rename asynchronously, however that approach was wrong
since it would allow the d_move() to occur after the directory's i_mutex
had been dropped by the original process.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

NFS uses some int, and unsigned int :1, and bool as flags in structs and
args.  Assert the preference for uniformly replacing these with the bool
type.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

The current code worked okay for getdents(), but getdents64() expects
the d_type field to get filled out properly in the stat structure.
Setting this field fixes xfstests generic/401.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

nfsd4_ops contains function pointers, and marking it as constant avoids
it being able to be used as an attach vector for code injections.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>

struct svc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

pc_count is the only writeable memeber of struct svc_procinfo, which is
a good candidate to be const-ified as it contains function pointers.

This patch moves it into out out struct svc_procinfo, and into a
separate writable array that is pointed to by struct svc_version.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Pass union nfsd4_op_u to the op_func callbacks instead of using unsafe
function pointer casts.

It also adds two missing structures to struct nfsd4_op.u to facilitate
this.
Signed-off-by: NChristoph Hellwig <hch@lst.de>