- In setxattr if we are setting a posix acl convert uids and gids from
  the current user namespace into the initial user namespace, before
  the xattrs are passed to the underlying filesystem.

  Untranslatable uids and gids are represented as -1 which
  posix_acl_from_xattr will represent as INVALID_UID or INVALID_GID.
  posix_acl_valid will fail if an acl from userspace has any
  INVALID_UID or INVALID_GID values.  In net this guarantees that
  untranslatable posix acls will not be stored by filesystems.

- In getxattr if we are reading a posix acl convert uids and gids from
  the initial user namespace into the current user namespace.

  Uids and gids that can not be tranlsated into the current user namespace
  will be represented as -1.

- Replace e_id in struct posix_acl_entry with an anymouns union of
  e_uid and e_gid.  For the short term retain the e_id field
  until all of the users are converted.

- Don't set struct posix_acl.e_id in the cases where the acl type
  does not use e_id.  Greatly reducing the use of ACL_UNDEFINED_ID.

- Rework the ordering checks in posix_acl_valid so that I use kuid_t
  and kgid_t types throughout the code, and so that I don't need
  arithmetic on uid and gid types.

Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

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

the only potentially subtle thing here: get_cached_acl()
is never called with the second argument other than
ACL_TYPE_{ACCESS,DEFAULT}.  IOW, that return ERR_PTR(-EINVAL)
in there might as well be BUG().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

again, that's what all callers pass to it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... seeing that this is what all callers pass to it anyway.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... so that &inode->i_mode could be passed to it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

so we can pass &inode->i_mode to it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

made static; no callers left outside of posix_acl.c.  posix_acl_clone() also
has lost all external callers and became static...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

new helper: posix_acl_create(&acl, gfp, mode_p).  Replaces acl with
modified clone, on failure releases acl and replaces with NULL.
Returns 0 or -ve on error.  All callers of posix_acl_create_masq()
switched.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

new helper: posix_acl_chmod(&acl, gfp, mode).  Replaces acl with modified
clone or with NULL if that has failed; returns 0 or -ve on error.  All
callers of posix_acl_chmod_masq() switched to that - they'd been doing
exactly the same thing.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

nfsacl_encode() allocates memory in certain cases.  This of course
is not guaranteed to work.

Since commit 9f06c719 "SUNRPC: New xdr_streams XDR encoder API", the
kernel's XDR encoders can't return a result indicating possibly a
failure, so a memory allocation failure in nfsacl_encode() has become
fatal (ie, the XDR code Oopses) in some cases.

However, the allocated memory is a tiny fixed amount, on the order
of 40-50 bytes.  We can easily use a stack-allocated buffer for
this, with only a wee bit of nose-holding.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This simple implementation just checks for no ACLs on the inode, and
if so, then the rcu-walk may proceed, otherwise fail it.

This could easily be extended to put acls under RCU and check them
under seqlock, if need be. But this implementation is enough to show
the rcu-walk aware permissions code for path lookups is working, and
will handle cases where there are no ACLs or ACLs in just the final
element.

This patch implicity converts tmpfs to rcu-aware permission check.
Subsequent patches onvert ext*, xfs, and, btrfs. Each of these uses
acl/permission code in a different way, so convert them all to provide
templates and proof of concept.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

This is required for cluster filesystems which want to use
cached ACLs so that they can invalidate the cache when
required.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>

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

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

helpers: get_cached_acl(inode, type), set_cached_acl(inode, type, acl),
forget_cached_acl(inode, type).

ubifs/xattr.c needed includes reordered, the rest is a plain switchover.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

 - added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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!