The fattrs used in the NFSv3 getacl/setacl calls are not being properly
initialized. This occasionally causes nfs_update_inode to fall into
NFSv4 specific codepaths when handling post-op attrs from these calls.

Thanks to Cai Qian for noticing the spurious NFSv4 messages in debug
output from a v3 mount...
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

...and ensure that we obey the NFS_INO_INVALID_ACL flag when retrieving the
acls.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The lower level routines in fs/nfs/proc.c, fs/nfs/nfs3proc.c and
fs/nfs/nfs4proc.c should already be dealing with the revalidation issues.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix two errors in the client-side acl cache: First, when nfs3_proc_getacl
requests only the default acl of a file and the access acl is not cached
already, a NULL access acl entry is cached instead of ERR_PTR(-EAGAIN)
("not cached").

Second, update the cached acls in nfs3_proc_setacls: nfs_refresh_inode does
not always invalidate the cached acls, and when it does not, the cached acls
get out of sync.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clean-up: replace rpc_call() helper with direct call to rpc_call_sync.

This makes NFSv2 and NFSv3 synchronous calls more computationally
efficient, and reduces stack consumption in functions that used to
invoke rpc_call more than once.

Test plan:
Compile kernel with CONFIG_NFS enabled.  Connectathon on NFS version 2,
version 3, and version 4 mount points.
Signed-off-by: NChuck Lever <cel@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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: NChuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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: NChuck Lever <cel@netapp.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Looks like it sneaked back with the NFS ACL merge..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 Initialize the inode cache values correctly.
 Clean up __nfs3_forget_cached_acls()
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 Attach acls to inodes in the icache to avoid unnecessary GETACL RPC
 round-trips.  As long as the client doesn't retrieve any acls itself, only the
 default acls of exiting directories and the default and access acls of new
 directories will end up in the cache, which preserves some memory compared to
 always caching the access and default acl of all files.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Acked-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 NFSv3 has no concept of a umask on the server side: The client applies
 the umask locally, and sends the effective permissions to the server.
 This behavior is wrong when files are created in a directory that has a
 default ACL.  In this case, the umask is supposed to be ignored, and
 only the default ACL determines the file's effective permissions.

 Usually its the server's task to conditionally apply the umask.  But
 since the server knows nothing about the umask, we have to do it on the
 client side.  This patch tries to fetch the parent directory's default
 ACL before creating a new file, computes the appropriate create mode to
 send to the server, and finally sets the new file's access and default
 acl appropriately.

 Many thanks to Buck Huppmann <buchk@pobox.com> for sending the initial
 version of this patch, as well as for arguing why we need this change.
Signed-off-by: NAndreas Gruenbacher <agruen@suse.de>
Acked-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

 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: NAndreas Gruenbacher <agruen@suse.de>
Acked-by: NOlaf Kirch <okir@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>