kAFS can be given certain network errors (EADDRNOTAVAIL, EHOSTDOWN and
ERFKILL) that it doesn't handle in its server/address rotation algorithms.
They cause the probing and rotation to abort immediately rather than
rotating.

Fix this by:

 (1) Abstracting out the error prioritisation from the VL and FS rotation
     algorithms into a common function and expand usage into the server
     probing code.

     When multiple errors are available, this code selects the one we'd
     prefer to return.

 (2) Add handling for EADDRNOTAVAIL, EHOSTDOWN and ERFKILL.

Fixes: 0fafdc9f888b ("afs: Fix file locking")
Fixes: 0338747d8454 ("afs: Probe multiple fileservers simultaneously")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The AFS abort code space is shared across all services, so there's no need
for separate abort_to_error translators for each service.

Consolidate them into a single function and remove the function pointers
for them.

Signed-off-by: David Howells <dhowells@redhat.com>

Move the protocol description header file into net/rxrpc/ and rename it to
protocol.h.  It's no longer necessary to expose it as packets are no longer
exposed to kernel services (such as AFS) that use the facility.

The abort codes are transferred to the UAPI header instead as we pass these
back to userspace and also to kernel services.

Signed-off-by: David Howells <dhowells@redhat.com>

When we are given an invalid operation ID, we should abort that with
RXGEN_OPCODE rather than RX_INVALID_OPERATION.

Also map RXGEN_OPCODE to -ENOTSUPP.

Signed-off-by: David Howells <dhowells@redhat.com>

This should cover the set emitted by viced and the volume server.

Signed-off-by: Nathaniel Wesley Filardo <nwf@cs.jhu.edu>
Signed-off-by: David Howells <dhowells@redhat.com>

Authentication error abort codes should be translated to appropriate
Linux error codes, rather than all being translated to EREMOTEIO - which
indicates that the server had internal problems.

Additionally, a server shouldn't be marked unavailable and the next
server tried if an authentication error occurs.  This will quickly make
all the servers unavailable to the client.  Instead the error should be
returned straight to the user.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Implement file locking for AFS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Make some miscellaneous changes to the AFS filesystem:

 (1) Assert RCU barriers on module exit to make sure RCU has finished with
     callbacks in this module.

 (2) Correctly handle the AFS server returning a zero-length read.

 (3) Split out data zapping calls into one function (afs_zap_data).

 (4) Rename some afs_file_*() functions to afs_*() where they apply to
     non-regular files too.

 (5) Be consistent about the presentation of volume ID:vnode ID in debugging
     output.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add support for the create, link, symlink, unlink, mkdir, rmdir and
rename VFS operations to the in-kernel AFS filesystem.

Also:

 (1) Fix dentry and inode revalidation.  d_revalidate should only look at
     state of the dentry.  Revalidation of the contents of an inode pointed to
     by a dentry is now separate.

 (2) Fix afs_lookup() to hash negative dentries as well as positive ones.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make the in-kernel AFS filesystem use AF_RXRPC instead of the old RxRPC code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>