At the moment, afs_break_callbacks calls afs_break_one_callback() for each
separate FID it was given, and the latter looks up the volume individually
for each one.

However, this is inefficient if two or more FIDs have the same vid as we
could reuse the volume.  This is complicated by cell aliasing whereby we
may have multiple cells sharing a volume and can therefore have multiple
callback interests for any particular volume ID.

At the moment afs_break_one_callback() scans the entire list of volumes
we're getting from a server and breaks the appropriate callback in every
matching volume, regardless of cell.  This scan is done for every FID.

Optimise callback breaking by the following means:

 (1) Sort the FID list by vid so that all FIDs belonging to the same volume
     are clumped together.

     This is done through the use of an indirection table as we cannot do
     an insertion sort on the afs_callback_break array as we decode FIDs
     into it as we subsequently also have to decode callback info into it
     that corresponds by array index only.

     We also don't really want to bubblesort afterwards if we can avoid it.

 (2) Sort the server->cb_interests array by vid so that all the matching
     volumes are grouped together.  This permits the scan to stop after
     finding a record that has a higher vid.

 (3) When breaking FIDs, we try to keep server->cb_break_lock as long as
     possible, caching the start point in the array for that volume group
     as long as possible.

     It might make sense to add another layer in that list and have a
     refcounted volume ID anchor that has the matching interests attached
     to it rather than being in the list.  This would allow the lock to be
     dropped without losing the cursor.
Signed-off-by: David Howells <dhowells@redhat.com>

Alter the dynroot mount so that cells created by manipulation of
/proc/fs/afs/cells and /proc/fs/afs/rootcell and by specification of a root
cell as a module parameter will cause directories for those cells to be
created in the dynamic root superblock for the network namespace[*].

To this end:

 (1) Only one dynamic root superblock is now created per network namespace
     and this is shared between all attempts to mount it.  This makes it
     easier to find the superblock to modify.

 (2) When a dynamic root superblock is created, the list of cells is walked
     and directories created for each cell already defined.

 (3) When a new cell is added, if a dynamic root superblock exists, a
     directory is created for it.

 (4) When a cell is destroyed, the directory is removed.

 (5) These directories are created by calling lookup_one_len() on the root
     dir which automatically creates them if they don't exist.

[*] Inasmuch as network namespaces are currently supported here.
Signed-off-by: David Howells <dhowells@redhat.com>

Remove the restriction on DNS lookup upcalls that prevents ipv6 addresses
from being looked up.
Signed-off-by: David Howells <dhowells@redhat.com>

Show all of a server's addresses in /proc/fs/afs/servers, placing the
second plus addresses on padded lines of their own.  The current address is
marked with a star.
Signed-off-by: David Howells <dhowells@redhat.com>

The AFS filesystem depends at the moment on /proc for configuration and
also presents information that way - however, this causes a compilation
failure if procfs is disabled.

Fix it so that the procfs bits aren't compiled in if procfs is disabled.

This means that you can't configure the AFS filesystem directly, but it is
still usable provided that an up-to-date keyutils is installed to look up
cells by SRV or AFSDB DNS records.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>

Make calculation of the size of the inline name in struct proc_dir_entry
automatic, rather than having to manually encode the numbers and failing to
allow for lockdep.

Require a minimum inline name size of 33+1 to allow for names that look
like two hex numbers with a dash between.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

backmerge AFS fixes that went into mainline and deal with
the conflict in fs/afs/fsclient.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Implement network namespacing within AFS, but don't yet let mounts occur
outside the init namespace.  An additional patch will be required propagate
the network namespace across automounts.
Signed-off-by: David Howells <dhowells@redhat.com>

The afs_net::ws_cell member is sometimes used under RCU conditions from
within an seq-readlock.  It isn't, however, marked __rcu and it isn't set
using the proper RCU barrier-imposing functions.

Fix this by annotating it with __rcu and using appropriate barriers to
make sure accesses are correctly ordered.

Without this, the code can produce the following warning:

>> fs/afs/proc.c:151:24: sparse: incompatible types in comparison expression (different address spaces)

Fixes: f044c884 ("afs: Lay the groundwork for supporting network namespaces")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>

Sparse doesn't appear able to handle the conditionally-taken locks in
xdr_decode_AFSFetchStatus(), even though the lock and unlock are both
contingent on the same unvarying function argument.

Deal with this by interpolating a wrapper function that takes the lock if
needed and calls xdr_decode_AFSFetchStatus() on two separate branches, one
with the lock held and one without.

This allows Sparse to work out the locking.
Signed-off-by: David Howells <dhowells@redhat.com>

Provide two extra functions, proc_create_net_data_write() and
proc_create_net_single_write() that act like their non-write versions but
also set a write method in the proc_dir_entry struct.

An internal simple write function is provided that will copy its buffer and
hand it to the pde->write() method if available (or give an error if not).
The buffer may be modified by the write method.
Signed-off-by: David Howells <dhowells@redhat.com>

Rearrange fs/afs/proc.c to get rid of all the remaining predeclarations.
Signed-off-by: David Howells <dhowells@redhat.com>

Rearrange fs/afs/proc.c to move the show routines up to the top of each
block so the order is show, iteration, ops, file ops, fops.
Signed-off-by: David Howells <dhowells@redhat.com>

Rearrange fs/afs/proc.c by moving fops and open functions down so as to
remove predeclarations.
Signed-off-by: David Howells <dhowells@redhat.com>

In fs/afs/proc.c, move functions that create and remove /proc files to the
end of the source file as a first stage in getting rid of all the forward
declarations.
Signed-off-by: David Howells <dhowells@redhat.com>

Fixes: 2cd1f0dd ("isdn: replace ->proc_fops with ->proc_show")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This makes Alexey happy and Al groan.  Based on a patch from
Alexey Dobriyan.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Just set up the show callback in the tty_operations, and use
proc_create_single_data to create the file without additional
boilerplace code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Just set up the show callback in the tty_operations, and use
proc_create_single_data to create the file without additional
boilerplace code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

The driver proc file hasn't been writeable for a long time, so this is
just dead code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

And switch to proc_create_single_data.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And remove proc boilerplate code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.

Also don't bother handling proc_create* failures - the driver works
perfectly fine without the proc files, and the cleanup will handle
missing files gracefully.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use proc private data directly instead of doing a detour
through seq->private and private state.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And remove proc boilerplate code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use proc private data directly instead of doing a detour
through seq->private.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use proc private data directly instead of doing a detour
through seq->private.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use proc private data directly instead of doing a detour
through seq->private.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use proc private data directly instead of doing a detour
through seq->private.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And stop trying to get a reference on the submodule, procfs code deals
with release after an unloaded module and thus removed proc entry.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

And stop messing with try_module_get on THIS_MODULE, which doesn't make
any sense here.
Signed-off-by: Christoph Hellwig <hch@lst.de>

And use the root resource directly from the proc private data.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Unwind the registration loop into individual calls.  Switch to use
proc_create_single where applicable.

Also don't bother handling proc_create* failures - the driver works
perfectly fine without the proc files, and the cleanup will handle
missing files gracefully.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.

Also don't bother handling proc_create* failures - the driver works
perfectly fine without the proc files, and the cleanup will handle
missing files gracefully.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_single.

Also don't bother handling proc_create* failures - the driver works
perfectly fine without the proc files, and the cleanup will handle
missing files gracefully.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>