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>

Variant of proc_create_data that directly take a seq_file show
callback and deals with network namespaces in ->open and ->release.
All callers of proc_create + single_open_net converted over, and
single_{open,release}_net are removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>

This helper deals with single_{open,release}_net internals and thus
belongs here.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Just use the address family from the proc private data instead of copying
it into per-file data.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Remove a couple indirections to make the code look like most other
protocols.
Signed-off-by: Christoph Hellwig <hch@lst.de>

The code should be using the pid namespace from the procfs mount
instead of trying to look it up during open.
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Pass the hashtable to the proc private data instead of copying
it into the per-file private data.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Remove the pointless ping_seq_afinfo indirection and make the code look
like most other protocols.
Signed-off-by: Christoph Hellwig <hch@lst.de>