The NFS_INO_REVAL_FORCED flag now really only has meaning for the
case when we've just been handed a delegation for a file that was already
cached, and we're unsure about that cache.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It can be made static.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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

Consolidate the open-coded checking of NFS_I(inode)->cache_validity
into a couple of helper functions.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we're holding a delegation, we can skip sending the close-to-open
GETATTR until we're returning that delegation.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When looking at whether or not our dcache is valid, we really don't care
about the general state of the directory attribute cache. Instead, we
we only care about the state of the change attribute.

This fixes a performance issue when the client is responsible for
changing the directory contents; a number of NFSv4 operations will
atomically update the directory change attribute, but may not return
all the other attributes.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We should only care about checking the attributes if the page cache
is marked as dubious (using NFS_INO_REVAL_PAGECACHE) and the
NFS_INO_REVAL_FORCED flag is set.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the use called stat() on an 'ls -l' workload, and the attribute
cache was successfully revalidate by READDIRPLUS, then we want to
report that back so that the readdir code continues to use
readdirplus.
Reviewed-by: NBenjamin Coddington <bcodding@redhat.com>
Tested-by: NBenjamin Coddington <bcodding@redhat.com>
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>

An open file description (struct file) in a given process can be
associated with two different lock owners.

It can have a Posix lock owner which will be different in each process
that has a fd on the file.
It can have a Flock owner which will be the same in all processes.

When searching for a lock stateid to use, we need to consider both of these
owners

So add a new "flock_owner" to the "nfs_open_context" (of which there
is one for each open file description).

This flock_owner does not need to be reference-counted as there is a
1-1 relation between 'struct file' and nfs open contexts,
and it will never be part of a list of contexts.  So there is no need
for a 'flock_context' - just the owner is enough.

The io_count included in the (Posix) lock_context provides no
guarantee that all read-aheads that could use the state have
completed, so not supporting it for flock locks in not a serious
problem.  Synchronization between flock and read-ahead can be added
later if needed.

When creating an open_context for a non-openning create call, we don't have
a 'struct file' to pass in, so the lock context gets initialized with
a NULL owner, but this will never be used.

The flock_owner is not used at all in this patch, that will come later.
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>

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>

The NFS_INO_REVAL_FORCED flag needs to be set if we just got a delegation,
and we see that there might still be some ambiguity as to whether or not
our attribute or data cache are valid.
In practice, this means that a call to nfs_check_inode_attributes() will
have noticed a discrepancy between cached attributes and measured ones,
so let's move the setting of NFS_INO_REVAL_FORCED to there.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

A LAYOUTCOMMIT then subsequent GETATTR may both return the same attributes,
and in that case NFS_INO_INVALID_ATTR is never set on the second pass
through nfs_update_inode().  The existing check to skip the clearing of
NFS_INO_INVALID_ATTR if a LAYOUTCOMMIT is outstanding does not help in this
case (see commit 10b7e9ad: "pNFS: Don't mark the inode as revalidated
if a LAYOUTCOMMIT is outstanding").  We know that if a LAYOUTCOMMIT is
outstanding then attributes will need upating, so always set
NFS_INO_INVALID_ATTR.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

We know that the attributes will need updating if there is still a
LAYOUTCOMMIT outstanding.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When retrieving stat() information, NFS unfortunately does require us to
sync writes to disk in order to ensure that mtime and ctime are up to
date. However we shouldn't have to ensure that those writes are persisted.

Relaxing that requirement does mean that we may see an mtime/ctime change
if the server reboots and forces us to replay all writes.

The exception to this rule are pNFS clients that are required to send
layoutcommit, however that is dealt with by the call to pnfs_sync_inode()
in _nfs_revalidate_inode().
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

A file that is open for O_DIRECT is by definition not obeying
close-to-open cache consistency semantics, so let's not cache
the attributes too aggressively either.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

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

If we need to update the cached attributes, then we'd better make
sure that we also layoutcommit first. Otherwise, the server may have stale
attributes.

Prior to this patch, the revalidation code tried to "fix" this problem by
simply disabling attributes that would be affected by the layoutcommit.
That approach breaks nfs_writeback_check_extend(), leading to a file size
corruption.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we don't set the mode correctly in nfs_init_locked(), then there is
potential for a race with a second call to nfs_fhget that will cause
inode aliasing.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Unless the user is using file locking, we must assume close-to-open
cache consistency when the file is open for writing. Adjust the
caching algorithm so that it does not clear the cache on out-of-order
writes and/or attribute revalidations.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If there were outstanding writes then chalk up the unexpected change
attribute on the server to them.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

use d_alloc_parallel() for sillyunlink/lookup exclusion and
explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() -
a reader) for rmdir/sillyunlink one.

That ought to make lookup/readdir/!O_CREAT atomic_open really
parallel on NFS.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

NFS may be used as lower layer of overlayfs and accessing f_path.dentry can
lead to a crash.

Fix by replacing direct access of file->f_path.dentry with the
file_dentry() accessor, which will always return a native object.

Fixes: 4bacc9c9 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>
Tested-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: <stable@vger.kernel.org> # v4.2
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>

Just call inode_dio_wait directly instead of through a pointless wrapper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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 a NFSv4 client uses the cache_consistency_bitmask in order to
request only information about the change attribute, timestamps and
size, then it has not revalidated all attributes, and hence the
attribute timeout timestamp should not be updated.
Reported-by: NDonald Buczek <buczek@molgen.mpg.de>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

When we fail to queue a read page to IO descriptor,
we need to clean it up otherwise it is hanging around
preventing nfs module from being removed.

When we fail to queue a write page to IO descriptor,
we need to clean it up and also save the failure status
to open context. Then at file close, we can try to write
pages back again and drop the page if it fails to writeback
in .launder_page, which will be done in the next patch.
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>

based upon the corresponding patch from Neil's March patchset,
again with kmap-related horrors removed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If we pass in an empty nfs_fattr struct to nfs_update_inode, it will
(correctly) not update any of the attributes, but it then clears the
NFS_INO_INVALID_ATTR flag, which indicates that the attributes are
up to date. Don't clear the flag if the fattr struct has no valid
attrs to apply.
Reviewed-by: NSteve French <steve.french@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we get no post-op attributes back from a SETATTR operation, then no
attributes will of course be updated during the call to
nfs_update_inode.

We know however that the attributes are invalid at that point, since we
just changed some of them. At the very least, the ctime will be bogus.
If we get no post-op attributes back on the call, mark the attrcache
invalid to reflect that fact.
Reviewed-by: NSteve French <steve.french@primarydata.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

This reverts commit f895c53f.

This commit causes a NFSv4 regression in that close()+unlink() can end
up failing. The reason is that we no longer have a guarantee that the
CLOSE has completed on the server, meaning that the subsequent call to
REMOVE may fail with NFS4ERR_FILE_OPEN if the server implements Windows
unlink() semantics.
Reported-by: N&lt;Olga Kornievskaia <aglo@umich.edu>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If there is no cached data, then there is no need to track the file
change attribute on close.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Set rlimit for NFS's files is useless right now.
For local process's rlimit, it should be checked by nfs client.

The same, CIFS also call inode_change_ok checking rlimit at its client
in cifs_setattr_nounix() and cifs_setattr_unix().

v3, fix bad using of error
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If the ctime or mtime or change attribute have changed because
of an operation we initiated, we should make sure that we force
an attribute update. However we do not want to mark the page cache
for revalidation.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org # v4.0+

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

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

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