A later patch will need to perform a lookup using an
alternate client with a different security flavor.
This patch adds support for doing that on NFS v4.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Some filesystems (such as ext4) can return the same cookie value for
multiple files.  If we try to start a readdir with one of these cookies,
the server will return the first file found with a cookie of the same
value.  This can cause the client to enter an infinite loop.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs_opendir() created a context that held much more information than we
need for a readdir.  This patch introduces a slimmed-down
nfs_open_dir_context that contains only the cookie and the cred used for
RPC operations.  The new context will eventually be used to help detect
readdir loops.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we're doing a search by readdir cookie, we need to ensure that the
resulting f_pos is updated. To do so, we need to update the
desc->current_index, in the same way that we do in the search by
file offset case.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.

Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.

Have ->d_release() free it when dentry goes away.

Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Make NFS use the new d_automount() dentry operation rather than abusing
follow_link() on directories.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Commit c0204fd2 (NFS: Clean up
nfs4_proc_create()) broke NFSv3 exclusive open by removing the code
that passes the O_EXCL flag down to nfs3_proc_create(). This patch
reverts that offending hunk from the original commit.
Reported-by: NNick Bowler <nbowler@elliptictech.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org    [2.6.37]
Tested-by: NNick Bowler <nbowler@elliptictech.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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

vm_map_ram() is not available on NOMMU platforms, and causes trouble
on incoherrent architectures such as ARM when we access the page data
through both the direct and the virtual mapping.

The alternative is to use the direct mapping to access page data
for the case when we are not crossing a page boundary, but to copy
the data into a linear scratch buffer when we are accessing data
that spans page boundaries.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Cc: stable@kernel.org  [2.6.37]

Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

dcache_lock no longer protects anything. remove it.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.

This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

This patch make nfsv4 use the generic xattr handling code
to get the nfsv4 acl. This will help us to add richacl
support to nfsv4 in later patches
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We want to skip VFS applying mode for NFS. So set MS_POSIXACL always
and selectively use umask. Ideally we would want to use umask only
when we don't have inheritable ACEs set. But NFS currently don't
allow to send umask to the server. So this is best what we can do
and this is consistent with NFSv3
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Use ERR_CAST() intead of wierd-looking cast.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean up.

The pointer returned by ->decode_dirent() is no longer used as a
pointer.  The only call site (xdr_decode() in fs/nfs/dir.c) simply
extracts the errno value encoded in the pointer.  Replace the
returned pointer with a standard integer errno return value.

Also, pass the "server" argument as part of the nfs_entry instead of
as a separate parameter.  It's faster to derive "server" in
nfs_readdir_xdr_to_array() since we already have the directory's inode
handy.  "server" ought to be invariant for a set of entries in the
same directory, right?

The legacy versions of decode_dirent() don't use "server" anyway, so
it's wasted work for them to derive and pass "server" for each entry.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Tested-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

No functional changes, but clarify the code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we're searching for a specific cookie, and it isn't found in the page
cache, we should try an uncached_readdir(). To do so, we return EBADCOOKIE,
but we don't set desc->eof.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to ensure that the entries in the nfs_cache_array get cleared
when the page is removed from the page cache. To do so, we use the
freepage address_space operation.

Change nfs_readdir_clear_array to use kmap_atomic(), so that the
function can be safely called from all contexts.

Finally, modify the cache_page_release helper to call
nfs_readdir_clear_array directly, when dealing with an anonymous
page from 'uncached_readdir'.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We need to use the cookie from the previous array entry, not the
actual cookie that we are searching for (except for the case of
uncached_readdir).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

When comparing filehandles in the helper nfs_same_file(), we should not be
using 'strncmp()': filehandles are not null terminated strings.

Instead, we should just use the existing helper nfs_compare_fh().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Store the dirent->d_type in the struct nfs_cache_array_entry so that we
can use it in getdents() calls.

This fixes a regression with the new readdir code.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

It looks as if the array size calculation in MAX_READDIR_ARRAY does not
take the alignment of struct nfs_cache_array_entry into account.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We should ignore the errors from the filldir callback, and just interpret
them as meaning we should exit, however we should definitely pass back
ENOMEM errors.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently, uncached_readdir() is broken because if fails to handle
the results from nfs_readdir_xdr_to_array() correctly.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

nfs_do_filldir() must always free desc->page when it is done, otherwise
we end up leaking the page.

Also remove unused variable 'dentry'.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Some servers are known to be buggy w.r.t. this. Deal with them...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Strings allocated via kmemdup() in nfs_readdir_make_qstr() are
referenced from the nfs_cache_array which is stored in a page cache
page. Kmemleak does not scan such pages and it reports several false
positives. This patch annotates the string->name pointer so that
kmemleak does not consider it a real leak.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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

Fix up the issue that array->eof_index needs to be able to be set
even if array->size == 0.

Ensure that we catch all important memory allocation error conditions
and/or kmap() failures.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This reverts commit 80e60639.

This change requires further fixes to ensure that the open doesn't
succeed if the lookup later results in a regular file being created.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clones an existing reference to inode; caller must already hold one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Also some clean ups.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.

To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files.  Without readdir plus, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user    | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys     | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access  | 3         | 1         | 1         | 4         | 31
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 104       | 1,003     | 10,003    | 100,003   | 1,000,003
readdir | 2         | 16        | 158       | 1,575     | 15,749
total   | 111       | 1,021     | 10,163    | 101,583   | 1,015,784

With readdir plus enabled, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user    | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys     | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access  | 3         | 1         | 1         | 1         | 7
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 4         | 3         | 3         | 3         | 3
readdir | 6         | 62        | 630       | 6,300     | 62,993
total   | 15        | 67        | 635       | 6,305     | 63,004

Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Check if the decoded entry has the eof bit set when returning from xdr_decode
with an error.  If it does, we should set the eof bits in the array before
returning.  This should keep us from looping when we expect more data but the
server doesn't give us anything new.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>