Our UC-KLEE tool found a kernel memory leak of 512 bytes (on x86_64) for
each call to gssp_accept_sec_context_upcall()
(net/sunrpc/auth_gss/gss_rpc_upcall.c). Since it appears that this call
can be triggered by remote connections (at least, from a cursory a
glance at the call chain), it may be exploitable to cause kernel memory
exhaustion. We found the bug in kernel 3.16.3, but it appears to date
back to commit 9dfd87da (2013-08-20).

The gssp_accept_sec_context_upcall() function performs a pair of calls
to gssp_alloc_receive_pages() and gssp_free_receive_pages().  The first
allocates memory for arg->pages.  The second then frees the pages
pointed to by the arg->pages array, but not the array itself.
Reported-by: David A. Ramos <daramos@stanford.edu>
Fixes: 9dfd87da ("rpc: fix huge kmalloc's in gss-proxy”)
Signed-off-by: David A. Ramos <daramos@stanford.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Includes of pnfs.h in export.c and fcntl.c also bring in xdr4.h, which
won't build without CONFIG_NFSD_V3, breaking non-V3 builds.  Ifdef-out
most of pnfs.h in that case.
Reported-by: Bas Peters <baspeters93@gmail.com>
Reported-by: Jim Davis <jim.epost@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 9cf514cc "nfsd: implement pNFS operations"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

We're supposed to be testing that the fh_fsid's match but because the
parenthesis are in the wrong place, then we only check the first
byte.

Fixes: 9558f250 ('nfsd: add fh_fsid_match helper')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The code seems to work.  The protocol looks stable.  The kernel's
version defaults can be overridden by rpc.nfsd arguments.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Add a small shim between core nfsd and filesystems to translate the
somewhat cumbersome pNFS data structures and semantics to something
more palatable for Linux filesystems.

Thanks to Rick McNeal for the old prototype pNFS blocklayout server
code, which gave a lot of inspiration to this version even if no
code is left from it.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Add three methods to allow exporting pnfs block layout volumes:

 - get_uuid: get a filesystem unique signature exposed to clients
 - map_blocks: map and if nessecary allocate blocks for a layout
 - commit_blocks: commit blocks in a layout once the client is done with them

For now we stick the external pnfs block layout interfaces into s_export_op to
avoid mixing them up with the internal interface between the NFS server and
the layout drivers.  Once we've fully internalized the latter interface we
can redecide if these methods should stay in s_export_ops.
Signed-off-by: Christoph Hellwig <hch@lst.de>

For now just a few simple events to trace the layout stateid lifetime, but
these already were enough to find several bugs in the Linux client layout
stateid handling.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Add support to issue layout recalls to clients.  For now we only support
full-file recalls to get a simple and stable implementation.  This allows
to embedd a nfsd4_callback structure in the layout_state and thus avoid
any memory allocations under spinlocks during a recall.  For normal
use cases that do not intent to share a single file between multiple
clients this implementation is fully sufficient.

To ensure layouts are recalled on local filesystem access each layout
state registers a new FL_LAYOUT lease with the kernel file locking code,
which filesystems that support pNFS exports that require recalls need
to break on conflicting access patterns.

The XDR code is based on the old pNFS server implementation by
Andy Adamson, Benny Halevy, Boaz Harrosh, Dean Hildebrand, Fred Isaman,
Marc Eshel, Mike Sager and Ricardo Labiaga.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Add support for the GETDEVICEINFO, LAYOUTGET, LAYOUTCOMMIT and
LAYOUTRETURN NFSv4.1 operations, as well as backing code to manage
outstanding layouts and devices.

Layout management is very straight forward, with a nfs4_layout_stateid
structure that extends nfs4_stid to manage layout stateids as the
top-level structure.  It is linked into the nfs4_file and nfs4_client
structures like the other stateids, and contains a linked list of
layouts that hang of the stateid.  The actual layout operations are
implemented in layout drivers that are not part of this commit, but
will be added later.

The worst part of this commit is the management of the pNFS device IDs,
which suffers from a specification that is not sanely implementable due
to the fact that the device-IDs are global and not bound to an export,
and have a small enough size so that we can't store the fsid portion of
a file handle, and must never be reused.  As we still do need perform all
export authentication and validation checks on a device ID passed to
GETDEVICEINFO we are caught between a rock and a hard place.  To work
around this issue we add a new hash that maps from a 64-bit integer to a
fsid so that we can look up the export to authenticate against it,
a 32-bit integer as a generation that we can bump when changing the device,
and a currently unused 32-bit integer that could be used in the future
to handle more than a single device per export.  Entries in this hash
table are never deleted as we can't reuse the ids anyway, and would have
a severe lifetime problem anyway as Linux export structures are temporary
structures that can go away under load.

Parts of the XDR data, structures and marshaling/unmarshaling code, as
well as many concepts are derived from the old pNFS server implementation
from Andy Adamson, Benny Halevy, Dean Hildebrand, Marc Eshel, Fred Isaman,
Mike Sager, Ricardo Labiaga and many others.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Add a helper to check that the fsid parts of two file handles match.
Signed-off-by: Christoph Hellwig <hch@lst.de>

The pnfs code will need it too.  Also remove the nfsd_ prefix to match the
other filehandle helpers in that file.
Signed-off-by: Christoph Hellwig <hch@lst.de>

This (ab-)uses the file locking code to allow filesystems to recall
outstanding pNFS layouts on a file.  This new lease type is similar but
not quite the same as FL_DELEG.  A FL_LAYOUT lease can always be granted,
an a per-filesystem lock (XFS iolock for the initial implementation)
ensures not FL_LAYOUT leases granted when we would need to recall them.

Also included are changes that allow multiple outstanding read
leases of different types on the same file as long as they have a
differnt owner.  This wasn't a problem until now as nfsd never set
FL_LEASE leases, and no one else used FL_DELEG leases, but given that
nfsd will also issues FL_LAYOUT leases we will have to handle it now.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Just like for other lock types we should allow different owners to have
a read lease on a file.  Currently this can't happen, but with the addition
of pNFS layout leases we'll need this feature.
Signed-off-by: Christoph Hellwig <hch@lst.de>

This gives us a nice upper bound for later use in nfѕd.
Signed-off-by: Christoph Hellwig <hch@lst.de>

Christoph's block pnfs patches have some minor dependencies on these
lock patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The BKL is completely out of the picture in the lockd and sunrpc code
these days. Update the antiquated comments that refer to it.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Someone with a weird time_t happened to notice this, it shouldn't really
manifest till 2038.  It may not be our ownly year-2038 problem.
Reported-by: Aaron Pace <Aaron.Pace@alcatel-lucent.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Jeff Layton <jlayton@primarydata.com>

We have each of the locks_remove_* variants doing this individually.
Have the caller do it instead, and have locks_remove_flock and
locks_remove_lease just assume that it's a valid pointer.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>

This makes things a bit more efficient in the cifs and ceph lock
pushing code.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Now that we use standard list_heads for tracking leases, we can have
lm_change take a pointer to the lease to be modified instead of a
double pointer.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Nothing uses it anymore. Also add a forward declaration for struct
file_lock to silence some compiler warnings that the removal triggers.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

There is only a single call site for each of these functions, and the
caller takes the i_lock prior to calling them and drops it just
afterward. Move the spinlocking into the functions instead.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

The current scheme of using the i_flock list is really difficult to
manage. There is also a legitimate desire for a per-inode spinlock to
manage these lists that isn't the i_lock.

Start conversion to a new scheme to eventually replace the old i_flock
list with a new "file_lock_context" object.

We start by adding a new i_flctx to struct inode. For now, it lives in
parallel with i_flock list, but will eventually replace it. The idea is
to allocate a structure to sit in that pointer and act as a locus for
all things file locking.

We allocate a file_lock_context for an inode when the first lock is
added to it, and it's only freed when the inode is freed. We use the
i_lock to protect the assignment, but afterward it should mostly be
accessed locklessly.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

...instead of open-coding it and removing flock locks directly. This
helps consolidate the flock lock removal logic into a single spot.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>

...that we can use to queue file_locks to per-ctx list_heads. Go ahead
and convert locks_delete_lock and locks_dispose_list to use it instead
of the fl_block list.
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>

Pull fuse fixes from Miklos Szeredi:
 "This fixes a regression in the latest fuse update plus a fix for a
  rather theoretical memory ordering issue"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: add memory barrier to INIT
  fuse: fix LOOKUP vs INIT compat handling

Pull fbdev fixes from Tomi Valkeinen:
 - broadsheetfb: fix memory leak
 - simplefb: fix build failure on sparc

* tag 'fbdev-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
  fbdev/broadsheetfb: fix memory leak
  simplefb: Fix build failure on Sparc

Pull MMC bugfix from Ulf Hansson:
 "Fix sdhci regulator regression for Qualcomm and Nvidia boards"

* tag 'mmc-v3.19-4' of git://git.linaro.org/people/ulf.hansson/mmc:
  mmc: sdhci: Set SDHCI_POWER_ON with external vmmc

Pull m68k fixlet from Geert Uytterhoeven.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Wire up execveat

Pull powerpc fixes from Michael Ellerman:
 "A few powerpc fixes"

* tag 'powerpc-3.19-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc: Work around gcc bug in current_thread_info()
  cxl: Fix issues when unmapping contexts
  powernv: Fix OPAL tracepoint code