mm: make read_cache_page synchronous

Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

mm: make read_cache_page synchronous

Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.

I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd. All depending on whether the filler is async and/or can return
with a !uptodate page.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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NFS: Fix directory caching problem - with test case and patch.

Try running this script in an NFS mounted directory (Client relatively
recent - 2.6.18 has the problem as does 2.6.20).

NFS: Fix directory caching problem - with test case and patch.

Try running this script in an NFS mounted directory (Client relatively
recent - 2.6.18 has the problem as does 2.6.20).

------------------------------------------------------
#!/bin/bash
#
# This script will produce the following errormessage from tar:
#
# tar: newdir/innerdir/innerfile: file changed as we read it

# create dirs
rm -rf nfstest
mkdir -p nfstest/dir/innerdir

# create files (should not be empty)
echo "Hello World!" >nfstest/dir/file
echo "Hello World!" >nfstest/dir/innerdir/innerfile

# problem only happens if we sleep before chmod
sleep 1

# change file modes
chmod -R a+r nfstest

# rename dir
mv nfstest/dir nfstest/newdir

# tar it
tar -cf nfstest/nfstest.tar -C nfstest newdir

# restore old dir name
mv nfstest/newdir nfstest/dir
--------------------------------------------------------

What happens:

The 'chmod -R' does a readdir_plus in each directory and the results
get cached in the page cache. It then updates the ctime on each file
by one second. When this happens, the post-op attributes are used to
update the ctime stored on the client to match the value in the kernel.

The 'mv' calls shrink_dcache_parent on the directory tree which
flushes all the dentries (so a new lookup will be required) but
doesn't flush the inodes or pagecache.

The 'tar' does a readdir on each directory, but (in the case of
'innerdir' at least) satisfies it from the pagecache and uses the
READDIRPLUS data to update all the inodes. In the case of
'innerdir/innerfile', the ctime is out of date.

'tar' then calls 'lstat' on innerdir/innerfile getting an old ctime.
It then opens the file (triggering a GETATTR), reads the content, and
then calls fstat to see if anything has changed. It finds that ctime
has changed and so complains.

The problem seems to be that the cache readdirplus info is kept around
for too long.

My patch below discards pagecache data for directories when
dentry_iput is called on them. This effectively removes the symptom
which convinces me that I correctly understand the problem. However
I'm not convinced that is a proper solution, as there could easily be
other races that trigger the same problem without being affected by
this 'fix'.

One possibility would be to require that readdirplus pagecache data be
only used *once* to instantiate an inode. Somehow it should then be
invalidated so that if the dentry subsequently disappears, it will
cause a new request to the server to fill in the stat data.

Another possibility is to compare the cache_change_attribute on the
inode with something similar for the readdirplus info and reject the
info from readdirplus if it is too old.

I haven't tried to implement these and would value other opinions
before I do.

Thanks,
NeilBrown


Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Set meaningful value for fattr->time_start in readdirplus results.

Don't use uninitialsed value for fattr->time_start in readdirplus results.

The 'fattr' structure filled in by

NFS: Set meaningful value for fattr->time_start in readdirplus results.

Don't use uninitialsed value for fattr->time_start in readdirplus results.

The 'fattr' structure filled in by nfs3_decode_direct does not get a
value for ->time_start set.
Thus if an entry is for an inode that we already have in cache,
when nfs_readdir_lookup calls nfs_fhget, it will call nfs_refresh_inode
and may update the inode with out-of-date information.

Directories are read a page at a time, so each page could have a
different timestamp that "should" be used to set the time_start for
the fattr for info in that page. However storing the timestamp per
page is awkward. (We could stick in the first 4 bytes and only read 4092
bytes, but that is a bigger code change than I am interested it).

This patch ignores the readdir_plus attributes if a readdir finds the
information already in cache, and otherwise sets ->time_start to the time
the readdir request was sent to the server.

It might be nice to store - in the directory inode - the time stamp for
the earliest readdir request that is still in the page cache, so that we
don't ignore attribute data that we don't have to. This patch doesn't do
that.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Fix an Oops in nfs_setattr()

It looks like nfs_setattr() and nfs_rename() also need to test whether the
target is a regular file before calling nfs_wb_all()...

Signed-off-b

NFS: Fix an Oops in nfs_setattr()

It looks like nfs_setattr() and nfs_rename() also need to test whether the
target is a regular file before calling nfs_wb_all()...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Merge branch 'master' of /home/trondmy/kernel/linux-2.6/

Conflicts:

net/sunrpc/auth_gss/gss_krb5_crypto.c
net/sunrpc/auth_gss/gss_spkm3_token.c
net/s

Merge branch 'master' of /home/trondmy/kernel/linux-2.6/

Conflicts:

net/sunrpc/auth_gss/gss_krb5_crypto.c
net/sunrpc/auth_gss/gss_spkm3_token.c
net/sunrpc/clnt.c

Merge with mainline and fix conflicts.

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[PATCH] mark struct inode_operations const 2

Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing

[PATCH] mark struct inode_operations const 2

Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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NFS: Dont clobber more uptodate values in nfs_set_verifier()

nfs_lookup_revalidate and friends are not serialised, so it is currently
quite possible for the dentry to be revalidated, and

NFS: Dont clobber more uptodate values in nfs_set_verifier()

nfs_lookup_revalidate and friends are not serialised, so it is currently
quite possible for the dentry to be revalidated, and then have the
updated verifier replaced with an older value by another process.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Also use readdir info to revalidate positive dentries

If the fileid of the cached dentry fails to match that returned by
the readdir call, then we should also d_drop. Try to take in

NFS: Also use readdir info to revalidate positive dentries

If the fileid of the cached dentry fails to match that returned by
the readdir call, then we should also d_drop. Try to take into account the
fact that on NFSv4, readdir may return the "mounted_on_fileid" by looking
for submounts.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Fix a readdir/lookup inefficiency.

Make sure that nfs_readdir_lookup() handles negative dentries correctly.
If d_lookup() returns a negative dentry, then we need to d_drop() that

NFS: Fix a readdir/lookup inefficiency.

Make sure that nfs_readdir_lookup() handles negative dentries correctly.
If d_lookup() returns a negative dentry, then we need to d_drop() that
since readdir shows that it should be positive.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Fix up "rm -rf"...

When a file is being scheduled for deletion by means of the sillyrename
mechanism, it makes sense to start out writeback of the dirty data as
soon as possible

NFS: Fix up "rm -rf"...

When a file is being scheduled for deletion by means of the sillyrename
mechanism, it makes sense to start out writeback of the dirty data as
soon as possible in order to ensure that the delete can occur. Examples of
cases where this is an issue include "rm -rf", which will busy-wait until
the file is closed, and the sillyrename completes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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[PATCH] NFS: Fix races in nfs_revalidate_mapping()

Prevent the call to invalidate_inode_pages2() from racing with file writes
by taking the inode->i_mutex across the page cache flush and

[PATCH] NFS: Fix races in nfs_revalidate_mapping()

Prevent the call to invalidate_inode_pages2() from racing with file writes
by taking the inode->i_mutex across the page cache flush and invalidate.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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[PATCH] nfs: change uses of f_{dentry,vfsmnt} to use f_path

Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the nfs
client code.

Signed-off-by: Josef "Jeff" S

[PATCH] nfs: change uses of f_{dentry,vfsmnt} to use f_path

Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the nfs
client code.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] NFS: Cache invalidation fixup

If someone has renamed a directory on the server, triggering the d_move
code in d_materialise_unique(), then we need to invalidate the cached
di

[PATCH] NFS: Cache invalidation fixup

If someone has renamed a directory on the server, triggering the d_move
code in d_materialise_unique(), then we need to invalidate the cached
directory information in the source parent directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] VFS: Make d_materialise_unique() enforce directory uniqueness

If the caller tries to instantiate a directory using an inode that already
has a dentry alias, then we attempt to re

[PATCH] VFS: Make d_materialise_unique() enforce directory uniqueness

If the caller tries to instantiate a directory using an inode that already
has a dentry alias, then we attempt to rename the existing dentry instead
of instantiating a new one. Fail with an ELOOP error if the rename would
affect one of our parent directories.

This behaviour is needed in order to avoid issues such as

http://bugzilla.kernel.org/show_bug.cgi?id=7178

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] xdr annotations: NFS readdir entries

on-the-wire data is big-endian

[in large part pulled from Alexey's patch]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

[PATCH] xdr annotations: NFS readdir entries

on-the-wire data is big-endian

[in large part pulled from Alexey's patch]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] NFS: fix minor bug in new NFS symlink code

The original code confused a zero return code from pagevec_add() as success.

Test plan:
None.

Signed-off-by: Chuck Le

[PATCH] NFS: fix minor bug in new NFS symlink code

The original code confused a zero return code from pagevec_add() as success.

Test plan:
None.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] NFS: Deal with failure of invalidate_inode_pages2()

If invalidate_inode_pages2() fails, then it should in principle just be
because the current process was signalled. In that ca

[PATCH] NFS: Deal with failure of invalidate_inode_pages2()

If invalidate_inode_pages2() fails, then it should in principle just be
because the current process was signalled. In that case, we just want to
ensure that the inode's page cache remains marked as invalid.

Also add a helper to allow the O_DIRECT code to simply mark the page cache as
invalid once it is finished writing, instead of calling
invalidate_inode_pages2() itself.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] r/o bind mounts: monitor zeroing of i_nlink

Some filesystems, instead of simply decrementing i_nlink, simply zero it
during an unlink operation. We need to catch these in additi

[PATCH] r/o bind mounts: monitor zeroing of i_nlink

Some filesystems, instead of simply decrementing i_nlink, simply zero it
during an unlink operation. We need to catch these in addition to the
decrement operations.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] r/o bind mounts: unlink: monitor i_nlink

When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.

[PATCH] r/o bind mounts: unlink: monitor i_nlink

When a filesystem decrements i_nlink to zero, it means that a write must be
performed in order to drop the inode from the filesystem.

We're shortly going to have keep filesystems from being remounted r/o between
the time that this i_nlink decrement and that write occurs.

So, add a little helper function to do the decrements. We'll tie into it in a
bit to note when i_nlink hits zero.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

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[PATCH] Allow file systems to manually d_move() inside of ->rename()

Some file systems want to manually d_move() the dentries involved in a
rename. We can do this by making use of the F

[PATCH] Allow file systems to manually d_move() inside of ->rename()

Some file systems want to manually d_move() the dentries involved in a
rename. We can do this by making use of the FS_ODD_RENAME flag if we just
have nfs_rename() unconditionally do the d_move(). While there, we rename
the flag to be more descriptive.

OCFS2 uses this to protect that part of the rename operation with a cluster
lock.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>

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NFS: nfs_lookup - don't hash dentry when optimising away the lookup

If the open intents tell us that a given lookup is going to result in a,
exclusive create, we currently optimize away

NFS: nfs_lookup - don't hash dentry when optimising away the lookup

If the open intents tell us that a given lookup is going to result in a,
exclusive create, we currently optimize away the lookup call itself. The
reason is that the lookup would not be atomic with the create RPC call, so
why do it in the first place?

A problem occurs, however, if the VFS aborts the exclusive create operation
after the lookup, but before the call to create the file/directory: in this
case we will end up with a hashed negative dentry in the dcache that has
never been looked up.
Fix this by only actually hashing the dentry once the create operation has
been successfully completed.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Use cached page as buffer for NFS symlink requests

Now that we have a copy of the symlink path in the page cache, we can pass
a struct page down to the XDR routines instead of a str

NFS: Use cached page as buffer for NFS symlink requests

Now that we have a copy of the symlink path in the page cache, we can pass
a struct page down to the XDR routines instead of a string buffer.

Test plan:
Connectathon, all NFS versions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: copy symlinks into page cache before sending NFS SYMLINK request

Currently the NFS client does not cache symlinks it creates. They get
cached only when the NFS client reads them ba

NFS: copy symlinks into page cache before sending NFS SYMLINK request

Currently the NFS client does not cache symlinks it creates. They get
cached only when the NFS client reads them back from the server.

Copy the symlink into the page cache before sending it.

Test plan:
Connectathon, all NFS versions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: Fix double d_drop in nfs_instantiate() error path

If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning. But some callers already do a

NFS: Fix double d_drop in nfs_instantiate() error path

If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning. But some callers already do a d_drop in the case
of an error return. Make certain we do only one d_drop in all error paths.

This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API. To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.

Test plan:
Connectathon, all versions of NFS.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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NFS: remove a no-longer-needed error check in nfs_symlink()

In the early days of NFS, there was no duplicate reply cache on the server.
Thus retransmitted non-idempotent requests often f

NFS: remove a no-longer-needed error check in nfs_symlink()

In the early days of NFS, there was no duplicate reply cache on the server.
Thus retransmitted non-idempotent requests often found that the request had
already completed on the server. To avoid passing an unanticipated return
code to unsuspecting applications, NFS clients would often shunt error
codes that implied the request had been retried but already completed.

Thanks to NFS over TCP, duplicate reply caches on the server, and network
performance and reliability improvements, it is safe to remove such checks.

Test plan:
None.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

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