When starting to read or write with a layout segment, check that the
range matches our request.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Move the pNFS commit related operations into a separate structure
that can be carried by the pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Lift filelayout_search_commit_reqs() into the generic pnfs/nfs code,
and add support for commit arrays.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Enable adding and lookup of per-layout segment commits in filelayout
and flexfilelayout.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Ensure that both the file and flexfiles layout types clean up when
freeing the layout segments.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Add a pNFS callback to allow the O_DIRECT code to release the DS
commitinfo when freeing the dreq.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we have multiple layout segments with different lists of mirrored
data, we need to track the commits on a per layout segment basis.
This patch adds a list to support this tracking in struct
pnfs_ds_commit_info.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we receive a CB_RECALL_ANY that asks us to return flexfiles
layouts, we iterate through all the layouts and look at whether or
not there are active open file descriptors that might need them
for I/O. If there are no such descriptors, we return the layouts.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the cred assigned to the layout that we're updating differs from
the one used to retrieve the new layout segment, then we need to
update the layout plh_lc_cred field.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If the attempt to do pNFS fails, then record what action we
take to recover (resend, reset to pnfs or reset to mds).
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If a LAYOUTRETURN receives a reply of NFS4ERR_OLD_STATEID then assume we've
missed an update, and just bump the stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Both close and delegreturn have identical code to handle pNFS
return-on-close. This patch refactors that code and places it
in pnfs.c
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Add a helper for when we remove the explicit pointer to the open
context.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If we notice that a DS may be down, we should attempt to read from the
other mirrors first before we go back to retry the dead DS.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

If a bulk layout recall or a metadata server reboot coincides with a
umount, then holding a reference to an inode is unsafe unless we
also hold a reference to the super block.

Fixes: fd9a8d71 ("NFSv4.1: Fix bulk recall and destroy of layouts")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

SUNRPC has two sorts of credentials, both of which appear as
"struct rpc_cred".
There are "generic credentials" which are supplied by clients
such as NFS and passed in 'struct rpc_message' to indicate
which user should be used to authorize the request, and there
are low-level credentials such as AUTH_NULL, AUTH_UNIX, AUTH_GSS
which describe the credential to be sent over the wires.

This patch replaces all the generic credentials by 'struct cred'
pointers - the credential structure used throughout Linux.

For machine credentials, there is a special 'struct cred *' pointer
which is statically allocated and recognized where needed as
having a special meaning.  A look-up of a low-level cred will
map this to a machine credential.
Signed-off-by: NNeilBrown <neilb@suse.com>
Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

For the 'files' and 'flexfiles' layout types, we do not expect the reply
to be any larger than 4k. The block and scsi layout types are a little more
greedy, so we keep allocating the maximum response size for now.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

When we update the layout stateid in nfs4_layoutreturn_refresh_stateid, we
should also update the range in order to let the server know we're actually
returning everything.

Fixes: 16c278dbfa63 ("pnfs: Fix handling of NFS4ERR_OLD_STATEID replies...")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the server tells us that out layoutreturn raced with another layout
update, then we must ensure that the new layout segments are not in use
before we resend with an updated layout stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

If the layout was invalidated due to a reboot, then don't try to send
a layoutreturn for it.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

The flag was not always being cleared after LAYOUTGET on OPEN.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Move the actual freeing of the struct nfs4_layoutget into fs/nfs/pnfs.c
where it can be reused by the layoutget on open code.
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

This triggers when have no pre-existing inode to attach to.
The preexisting case is saved for later.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

They work better in the new alloc_init function.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

Driver can set flag to allow LAYOUTGET to be sent with OPEN.
Signed-off-by: NFred Isaman <fred.isaman@gmail.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>

PNFS block/SCSI layouts should gracefully handle cases where block devices
are not available when a layout is retrieved, or the block devices are
removed while the client holds a layout.

While setting up a layout segment, keep a record of an unavailable or
un-parsable block device in cache with a flag so that subsequent layouts do
not spam the server with GETDEVINFO.  We can reuse the current
NFS_DEVICEID_UNAVAILABLE handling with one variation: instead of reusing
the device, we will discard it and send a fresh GETDEVINFO after the
timeout, since the lookup and validation of the device occurs within the
GETDEVINFO response handling.

A lookup of a layout segment that references an unavailable device will
return a segment with the NFS_LSEG_UNAVAILABLE flag set.  This will allow
the pgio layer to mark the layout with the appropriate fail bit, which
forces subsequent IO to the MDS, and prevents spamming the server with
LAYOUTGET, LAYOUTRETURN.

Finally, when IO to a block device fails, look up the block device(s)
referenced by the pgio header, and mark them as unavailable.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If there's an error doing I/O to block device, and the client resends the
I/O to the MDS, the MDS must recall the layout from the client before
processing the I/O.  Let's preempt that exchange by returning the layout
before falling back to the MDS when there's an error.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If our layoutreturn on close operation returns an NFS4ERR_OLD_STATEID,
then try to update the stateid and retry. We know that there should
be no further LAYOUTGET requests being launched.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable pnfs_layout_hdr.plh_refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
Suggested-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NDavid Windsor <dwindsor@gmail.com>
Reviewed-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

atomic_t variables are currently used to implement reference
counters with the following properties:
 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable nfs4_pnfs_ds.ds_count is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
Suggested-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NDavid Windsor <dwindsor@gmail.com>
Reviewed-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Now that we no longer hold the inode->i_lock when manipulating the
commit lists, it is safe to call pnfs_put_lseg() again.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It's possible and acceptable for NFS to attempt to add requests beyond the
range of the current pgio->pg_lseg, a case which should be caught and
limited by the pg_test operation.  However, the current handling of this
case replaces pgio->pg_lseg with a new layout segment (after a WARN) within
that pg_test operation.  That will cause all the previously added requests
to be submitted with this new layout segment, which may not be valid for
those requests.

Fix this problem by only returning zero for the number of bytes to coalesce
from pg_test for this case which allows any previously added requests to
complete on the current layout segment.  The check for requests starting
out of range of the layout segment moves to pg_init, so that the
replacement of pgio->pg_lseg will be done when the next request is added.
Signed-off-by: NBenjamin Coddington <bcodding@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

If we have a layout segment cached in pgio->pg_lseg, we should check it
for validity before reusing it in a new RPC request. Otherwise, if we
recoalesce, we can end up looping forever.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

encode_layoutreturn and encode_layoutcommit are now unused. Let's
remove them.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

The nfs4_pnfs_ds_connect path can call rpc_create which can fail or it
can wait on another context to reach the same failure.

This checks that the rpc_create succeeded and returns the error to the
caller.

When an error is returned, both the files and flexfiles layouts will return
NULL from _prepare_ds(). The flexfiles layout will also return the layout
with the error NFS4ERR_NXIO.
Signed-off-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>

Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Add a callback to allow the flexfiles layout driver to initialise the
layout private payload.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>