Commit graph

174 commits

Author SHA1 Message Date
Trond Myklebust
e4eff1a622 SUNRPC: Clean up the sillyrename code
Fix a couple of bugs:
 - Don't rely on the parent dentry still being valid when the call completes.
   Fixes a race with shrink_dcache_for_umount_subtree()

 - Don't remove the file if the filehandle has been labelled as stale.

Fix a couple of inefficiencies
 - Remove the global list of sillyrenamed files. Instead we can cache the
   sillyrename information in the dentry->d_fsdata
 - Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:21:39 -04:00
Trond Myklebust
3062c532ad NFS: Use dentry->d_time to store the parent directory verifier.
This will free up the d_fsdata field for other use.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:21:39 -04:00
Trond Myklebust
a50f7951a3 NFS: Fix an Oops in the nfs_access_cache_shrinker()
The nfs_access_cache_shrinker may race with nfs_access_zap_cache().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:25 -04:00
Jeff Layton
83d93f2229 NFS: Use GFP_HIGHUSER for page allocation in nfs_symlink()
nfs_symlink() allocates a GFP_KERNEL page for the pagecache. Most
pagecache pages are allocated using GFP_HIGHUSER, and there's no reason
not to do that in nfs_symlink() as well.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2007-07-10 23:40:25 -04:00
Trond Myklebust
a0356862bc NFS: Fix nfs_reval_fsid()
We don't need to revalidate the fsid on the root directory. It suffices to
revalidate it on the current directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:24 -04:00
Trond Myklebust
ad389da79f NFSv4: Ensure asynchronous open() calls always pin the mountpoint
A number of race conditions may currently ensue if the user presses ^C
and then unmounts the partition while an asynchronous open() is in
progress.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:24 -04:00
Alexey Dobriyan
e8edc6e03a Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 09:18:19 -07:00
Trond Myklebust
10afec9081 NFS: Fix some 'sparse' warnings...
- fs/nfs/dir.c:610:8: warning: symbol 'nfs_llseek_dir' was not declared.
   Should it be static?
 - fs/nfs/dir.c:636:5: warning: symbol 'nfs_fsync_dir' was not declared.
   Should it be static?
 - fs/nfs/write.c:925:19: warning: symbol 'req' shadows an earlier one
 - fs/nfs/write.c:61:6: warning: symbol 'nfs_commit_rcu_free' was not
   declared. Should it be static?
 - fs/nfs/nfs4proc.c:793:5: warning: symbol 'nfs4_recover_expired_lease'
   was not declared. Should it be static?

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-05-14 19:33:46 -04:00
Jesper Juhl
7a13e93228 NFS: Kill the obsolete NFS_PARANOIA
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-05-09 17:58:01 -04:00
Trond Myklebust
e70c490810 NFS: Remove redundant check in nfs_check_verifier()
The check for nfs_attribute_timeout(dir) in nfs_check_verifier is
redundant: nfs_lookup_revalidate() will already call nfs_revalidate_inode()
on the parent dir when necessary.

The only case where this is not done is the case of a negative dentry. Fix
this case by moving up the revalidation code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-05-09 17:57:59 -04:00
Trond Myklebust
e62c2bba1f NFS: Fix a jiffie wraparound issue
dentry verifiers are always set to the parent directory's
cache_change_attribute. There is no reason to be testing for anything other
than equality when we're trying to find out if the dentry has been checked
since the last time the directory was modified.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-05-09 17:57:58 -04:00
Nick Piggin
6fe6900e1e 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>
2007-05-07 12:12:51 -07:00
Neil Brown
83672d392f 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>
2007-04-30 22:17:19 -07:00
Neil Brown
1f4eab7e7c 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>
2007-04-30 22:17:18 -07:00
Trond Myklebust
e1552e1998 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>
2007-04-14 21:46:47 -07:00
Trond Myklebust
d9bc125caf 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.
2007-02-12 22:43:25 -08:00
Arjan van de Ven
92e1d5be91 [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>
2007-02-12 09:48:46 -08:00
Trond Myklebust
c79ba787c1 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>
2007-02-03 15:35:05 -08:00
Trond Myklebust
ef75c7974b 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>
2007-02-03 15:35:04 -08:00
Trond Myklebust
df1d5d23d3 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>
2007-02-03 15:35:04 -08:00
Trond Myklebust
ccfeb50623 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>
2007-02-03 15:35:04 -08:00
Trond Myklebust
717d44e849 [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>
2007-01-24 12:31:06 -08:00
Josef "Jeff" Sipek
01cce933d8 [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>
2006-12-08 08:28:41 -08:00
Trond Myklebust
fc22617e45 [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>
2006-10-21 13:35:06 -07:00
Trond Myklebust
9eaef27b36 [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>
2006-10-21 13:35:06 -07:00
Al Viro
0dbb4c6799 [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>
2006-10-20 10:26:40 -07:00
Chuck Lever
39cf8a1374 [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>
2006-10-20 10:26:39 -07:00
Trond Myklebust
cd9ae2b6a7 [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>
2006-10-20 10:26:39 -07:00
Dave Hansen
ce71ec3684 [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>
2006-10-01 00:39:30 -07:00
Dave Hansen
9a53c3a783 [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>
2006-10-01 00:39:30 -07:00
Mark Fasheh
349457ccf2 [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>
2006-09-24 13:50:45 -07:00
Trond Myklebust
fd6840714d 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>
2006-09-22 23:25:01 -04:00
Chuck Lever
94a6d75320 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>
2006-09-22 23:24:53 -04:00
Chuck Lever
873101b337 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>
2006-09-22 23:24:53 -04:00
Chuck Lever
4f390c152b 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>
2006-09-22 23:24:52 -04:00
Chuck Lever
d3db90e270 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>
2006-09-22 23:24:52 -04:00
David Howells
54ceac4515 NFS: Share NFS superblocks per-protocol per-server per-FSID
The attached patch makes NFS share superblocks between mounts from the same
server and FSID over the same protocol.

It does this by creating each superblock with a false root and returning the
real root dentry in the vfsmount presented by get_sb(). The root dentry set
starts off as an anonymous dentry if we don't already have the dentry for its
inode, otherwise it simply returns the dentry we already have.

We may thus end up with several trees of dentries in the superblock, and if at
some later point one of anonymous tree roots is discovered by normal filesystem
activity to be located in another tree within the superblock, the anonymous
root is named and materialises attached to the second tree at the appropriate
point.

Why do it this way? Why not pass an extra argument to the mount() syscall to
indicate the subpath and then pathwalk from the server root to the desired
directory? You can't guarantee this will work for two reasons:

 (1) The root and intervening nodes may not be accessible to the client.

     With NFS2 and NFS3, for instance, mountd is called on the server to get
     the filehandle for the tip of a path. mountd won't give us handles for
     anything we don't have permission to access, and so we can't set up NFS
     inodes for such nodes, and so can't easily set up dentries (we'd have to
     have ghost inodes or something).

     With this patch we don't actually create dentries until we get handles
     from the server that we can use to set up their inodes, and we don't
     actually bind them into the tree until we know for sure where they go.

 (2) Inaccessible symbolic links.

     If we're asked to mount two exports from the server, eg:

	mount warthog:/warthog/aaa/xxx /mmm
	mount warthog:/warthog/bbb/yyy /nnn

     We may not be able to access anything nearer the root than xxx and yyy,
     but we may find out later that /mmm/www/yyy, say, is actually the same
     directory as the one mounted on /nnn. What we might then find out, for
     example, is that /warthog/bbb was actually a symbolic link to
     /warthog/aaa/xxx/www, but we can't actually determine that by talking to
     the server until /warthog is made available by NFS.

     This would lead to having constructed an errneous dentry tree which we
     can't easily fix. We can end up with a dentry marked as a directory when
     it should actually be a symlink, or we could end up with an apparently
     hardlinked directory.

     With this patch we need not make assumptions about the type of a dentry
     for which we can't retrieve information, nor need we assume we know its
     place in the grand scheme of things until we actually see that place.

This patch reduces the possibility of aliasing in the inode and page caches for
inodes that may be accessed by more than one NFS export. It also reduces the
number of superblocks required for NFS where there are many NFS exports being
used from a server (home directory server + autofs for example).

This in turn makes it simpler to do local caching of network filesystems, as it
can then be guaranteed that there won't be links from multiple inodes in
separate superblocks to the same cache file.

Obviously, cache aliasing between different levels of NFS protocol could still
be a problem, but at least that gives us another key to use when indexing the
cache.

This patch makes the following changes:

 (1) The server record construction/destruction has been abstracted out into
     its own set of functions to make things easier to get right.  These have
     been moved into fs/nfs/client.c.

     All the code in fs/nfs/client.c has to do with the management of
     connections to servers, and doesn't touch superblocks in any way; the
     remaining code in fs/nfs/super.c has to do with VFS superblock management.

 (2) The sequence of events undertaken by NFS mount is now reordered:

     (a) A volume representation (struct nfs_server) is allocated.

     (b) A server representation (struct nfs_client) is acquired.  This may be
     	 allocated or shared, and is keyed on server address, port and NFS
     	 version.

     (c) If allocated, the client representation is initialised.  The state
     	 member variable of nfs_client is used to prevent a race during
     	 initialisation from two mounts.

     (d) For NFS4 a simple pathwalk is performed, walking from FH to FH to find
     	 the root filehandle for the mount (fs/nfs/getroot.c).  For NFS2/3 we
     	 are given the root FH in advance.

     (e) The volume FSID is probed for on the root FH.

     (f) The volume representation is initialised from the FSINFO record
     	 retrieved on the root FH.

     (g) sget() is called to acquire a superblock.  This may be allocated or
     	 shared, keyed on client pointer and FSID.

     (h) If allocated, the superblock is initialised.

     (i) If the superblock is shared, then the new nfs_server record is
     	 discarded.

     (j) The root dentry for this mount is looked up from the root FH.

     (k) The root dentry for this mount is assigned to the vfsmount.

 (3) nfs_readdir_lookup() creates dentries for each of the entries readdir()
     returns; this function now attaches disconnected trees from alternate
     roots that happen to be discovered attached to a directory being read (in
     the same way nfs_lookup() is made to do for lookup ops).

     The new d_materialise_unique() function is now used to do this, thus
     permitting the whole thing to be done under one set of locks, and thus
     avoiding any race between mount and lookup operations on the same
     directory.

 (4) The client management code uses a new debug facility: NFSDBG_CLIENT which
     is set by echoing 1024 to /proc/net/sunrpc/nfs_debug.

 (5) Clone mounts are now called xdev mounts.

 (6) Use the dentry passed to the statfs() op as the handle for retrieving fs
     statistics rather than the root dentry of the superblock (which is now a
     dummy).

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:37 -04:00
David Howells
8fa5c000d7 NFS: Move rpc_ops from nfs_server to nfs_client
Move the rpc_ops from the nfs_server struct to the nfs_client struct as they're
common to all server records of a particular NFS protocol version.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:35 -04:00
Trond Myklebust
979df72e6f NFS: Add an ACCESS cache memory shrinker
A pinned inode may in theory end up filling memory with cached ACCESS
calls. This patch ensures that the VM may shrink away the cache in these
particular cases.
The shrinker works by iterating through the list of inodes on the global
nfs_access_lru_list, and removing the least recently used access
cache entry until it is done (or until the entire cache is empty).

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:29 -04:00
Trond Myklebust
cfcea3e8c6 NFS: Add a global LRU list for the ACCESS cache
...in order to allow the addition of a memory shrinker.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:29 -04:00
Trond Myklebust
1c3c07e9f6 NFS: Add a new ACCESS rpc call cache to the linux nfs client
The current access cache only allows one entry at a time to be cached for each
inode. Add a per-inode red-black tree in order to allow more than one to
be cached at a time.

Should significantly cut down the time spent in path traversal for shared
directories such as ${PATH}, /usr/share, etc.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-09-22 23:24:28 -04:00
Trond Myklebust
4e0641a7ad NFS: Optimise away an excessive GETATTR call when a file is symlinked
In the case when compiling via a symlink tree, we want to ensure that the
close-to-open GETATTR call is applied only to the final file, and not to
the symlink.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-07-05 13:17:13 -04:00
Trond Myklebust
55a975937d NFS: Ensure the client submounts, when it crosses a server mountpoint.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-06-09 09:34:19 -04:00
Trond Myklebust
44b11874ff NFS: Separate metadata and page cache revalidation mechanisms
Separate out the function of revalidating the inode metadata, and
revalidating the mapping. The former may be called by lookup(),
and only really needs to check that permissions, ctime, etc haven't changed
whereas the latter needs only done when we want to read data from the page
cache, and may need to sync and then invalidate the mapping.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-06-09 09:34:09 -04:00
Carsten Otte
7451c4f0ee NFS: remove needless check in nfs_opendir()
Local variable res was initialized to 0 - no check needed here.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-04-19 13:06:37 -04:00
Arjan van de Ven
4b6f5d20b0 [PATCH] Make most file operations structs in fs/ const
This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28 09:16:06 -08:00
Trond Myklebust
03f28e3a20 NFS: Make nfs_fhget() return appropriate error values
Currently it returns NULL, which usually gets interpreted as ENOMEM. In
fact it can mean a host of issues.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-03-20 13:44:48 -05:00
Chuck Lever
1e7cb3dc12 NFS: directory trace messages
Reuse NFSDBG_DIRCACHE and NFSDBG_LOOKUPCACHE to provide additional
diagnostic messages that trace the operation of the NFS client's
directory behavior.  A few new messages are now generated when NFSDBG_VFS
is active, as well, to trace normal VFS activity.  This compromise
provides better trace debugging for those who use pre-built kernels,
without adding a lot of extra noise to the standard debug settings.

Test-plan:
Enable NFS trace debugging with flags 1, 2, or 4.  You should be able to
see different types of trace messages with each flag setting.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-03-20 13:44:24 -05:00
Chuck Lever
91d5b47023 NFS: add I/O performance counters
Invoke the byte and event counter macros where we want to count bytes and
events.

Clean-up: fix a possible NULL dereference in nfs_lock, and simplify
nfs_file_open.

Test-plan:
fsx and iozone on UP and SMP systems, with and without pre-emption.  Watch
for memory overwrite bugs, and performance loss (significantly more CPU
required per op).

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-03-20 13:44:14 -05:00
Jes Sorensen
1b1dcc1b57 [PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.

Modified-by: Ingo Molnar <mingo@elte.hu>

(finished the conversion)

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2006-01-09 15:59:24 -08:00
Trond Myklebust
24174119c7 NFSv4: Ensure that we return the delegation on the target of a rename too.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2006-01-06 14:58:50 -05:00
Trond Myklebust
5ba7cc4801 NFS: Fix post-op attribute revalidation...
- Missing nfs_mark_for_revalidate in nfs_proc_link()
  - Missing nfs_mark_for_revalidate in nfs_rename()

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-12-03 15:20:17 -05:00
Trond Myklebust
34ea818846 NFSv4: Return any delegations before sillyrenaming the file
I missed this one... Any form of rename will result in a delegation
 recall, so it is more efficient to return the one we hold before
 trying the rename.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-11-04 15:35:02 -05:00
Trond Myklebust
cf80955614 NFS: Ensure that nfs_link() instantiates the dentry correctly
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-27 22:12:42 -04:00
Chuck Lever
0c70b50150 NFS: nfs_lookup doesn't need to revalidate the parent directory's inode
nfs_lookup() used to consult a lookup cache before trying an actual wire
 lookup operation.  The lookup cache would be invalid, of course, if the
 parent directory's mtime had changed, so nfs_lookup performed an inode
 revalidation on the parent.

 Since nfs_lookup() doesn't use a cache anymore, the revalidation is no
 longer necessary.  There are cases where it will generate a lot of
 unnecessary GETATTR traffic.

 See http://bugzilla.linux-nfs.org/show_bug.cgi?id=9

 Test-plan:
 Use lndir and "rm -rf" and watch for excess GETATTR traffic or application
 level errors.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-27 22:12:40 -04:00
Trond Myklebust
0e574af1be NFS: Cleanup initialisation of struct nfs_fattr
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-27 22:12:38 -04:00
Trond Myklebust
6fe43f9e37 NFS: Fix rename of directory onto empty directory
If someone tries to rename a directory onto an empty directory, we
 currently fail and return EBUSY.
 This patch ensures that we try the rename if both source and target
 are directories, and that we fail with a correct error of EISDIR if
 the source is not a directory.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-18 14:20:22 -07:00
Trond Myklebust
cae7a073a4 NFSv4: Return delegation upon rename or removal of file.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-18 14:20:19 -07:00
Trond Myklebust
6f926b5ba7 [NFS]: Check that the server returns a valid regular file to our OPEN request
Since it appears that some servers don't...

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-18 14:20:18 -07:00
Trond Myklebust
02a913a73b NFSv4: Eliminate nfsv4 open race...
Make NFSv4 return the fully initialized file pointer with the
 stateid that it created in the lookup w/intent.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-10-18 14:20:17 -07:00
Trond Myklebust
9aa48b7e27 NFS: Don't expose internal READDIR errors to userspace
Fixes a condition whereby the kernel is returning the non-POSIX error
 EBADCOOKIE to userspace.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-09-23 12:38:01 -04:00
Trond Myklebust
20509f1bc5 NFS: Drop inode after rename
When doing a rename on top of an existing file that is not in use,
 the inode of the overwritten file will remain in the icache.

 The fix is to decrement i_nlink of the overwritten inode, like we
 do for unlink, rmdir etc already.

 Problem diagnosed by Olaf Kirch. This patch is a slight variation
 on his fix.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-09-23 12:37:58 -04:00
Steve Dickson
01c314a0c0 [PATCH] NFSv4: unbalanced BKL in nfs_atomic_lookup()
Added missing unlock_kernel() to NFSv4 atomic lookup.

Signed-off-by: Steve Dickson <steved@redhat.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>
2005-08-19 18:44:56 -07:00
Chuck Lever
dc59250c6e [PATCH] NFS: Introduce the use of inode->i_lock to protect fields in nfsi
Down the road we want to eliminate the use of the global kernel lock entirely
from the NFS client.  To do this, we need to protect the fields in the
nfs_inode structure adequately.  Start by serializing updates to the
"cache_validity" field.

Note this change addresses an SMP hang found by njw@osdl.org, where processes
deadlock because nfs_end_data_update and nfs_revalidate_mapping update the
"cache_validity" field without proper serialization.

Test plan:
 Millions of fsx ops on SMP clients.  Run Nick Wilson's breaknfs program on
 large SMP clients.

Signed-off-by: Chuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18 12:53:57 -07:00
Chuck Lever
412d582ec1 [PATCH] NFS: use atomic bitops to manipulate flags in nfsi->flags
Introduce atomic bitops to manipulate the bits in the nfs_inode structure's
"flags" field.

Using bitops means we can use a generic wait_on_bit call instead of an ad hoc
locking scheme in fs/nfs/inode.c, so we can remove the "nfs_i_wait" field from
nfs_inode at the same time.

The other new flags field will continue to use bitmask and logic AND and OR.
This permits several flags to be set at the same time efficiently.  The
following patch adds a spin lock to protect these flags, and this spin lock
will later cover other fields in the nfs_inode structure, amortizing the cost
of using this type of serialization.

Test plan:
 Millions of fsx ops on SMP clients.

Signed-off-by: Chuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18 12:53:56 -07:00
Chuck Lever
5529680981 [PATCH] NFS: split nfsi->flags into two fields
Certain bits in nfsi->flags can be manipulated with atomic bitops, and some
are better manipulated via logical bitmask operations.

This patch splits the flags field into two.  The next patch introduces atomic
bitops for one of the fields.

Test plan:
 Millions of fsx ops on SMP clients.

Signed-off-by: Chuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18 12:53:56 -07:00
Trond Myklebust
f0dd2136da [PATCH] NFS: Clean up readdir changes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:34 -04:00
Olivier Galibert
00a9264227 [PATCH] NFS: Hide NFS server-generated readdir cookies from userland
NFSv3 currently returns the unsigned 64-bit cookie directly to
 userspace. The following patch causes the kernel to generate
 loff_t offsets for the benefit of userland.
 The current server-generated READDIR cookie is cached in the
 nfs_open_context instead of in filp->f_pos, so we still end up work
 correctly under directory insertions/deletion.

 Signed-off-by: Olivier Galibert <galibert@pobox.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:33 -04:00
Andreas Gruenbacher
b7fa0554cf [PATCH] NFS: Add support for NFSv3 ACLs
This adds acl support fo nfs clients via the NFSACL protocol extension, by
 implementing the getxattr, listxattr, setxattr, and removexattr iops for the
 system.posix_acl_access and system.posix_acl_default attributes.  This patch
 implements a dumb version that uses no caching (and thus adds some overhead).
 (Another patch in this patchset adds caching as well.)

 Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
 Acked-by: Olaf Kirch <okir@suse.de>
 Signed-off-by: Andrew Morton <akpm@osdl.org>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:24 -04:00
J. Bruce Fields
6b3b5496d7 [PATCH] NFSv4: Add {get,set,list}xattr methods for nfs4
Add {get,set,list}xattr methods for nfs4.  The new methods are no-ops, to be
 used by subsequent ACL patch.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:10 -04:00
Trond Myklebust
a656db9987 [PATCH] NFS: Remove unused NFS inode field readdir_timestamp.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:07 -04:00
Trond Myklebust
4ce79717ce [PATCH] NFS: Header file cleanup...
- Move NFSv4 state definitions into a private header file.
 - Clean up gunk in nfs_fs.h

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2005-06-22 16:07:06 -04:00
Trond Myklebust
1d6757fbff [PATCH] NFS: Fix lookup intent handling
We should never apply a lookup intent to anything other than the last
path component in an open(), create() or access() call.

Introduce the helper nfs_lookup_check_intent() which always returns
zero if LOOKUP_CONTINUE or LOOKUP_PARENT are set, and returns the
intent flags if we're on the last component of the lookup.
By doing so, we fix a bug in open(O_EXCL), where we may end up
optimizing away a real lookup of the parent directory.

Problem noticed by Linda Dunaphant <linda.dunaphant@ccur.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-07 15:53:47 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00