If the underlying filesystem supports multiple layout types, then there
is little reason not to advertise that fact to clients and let them
choose what type to use.

Turn the ex_layout_type field into a bitfield. For each supported
layout type, we set a bit in that field. When the client requests a
layout, ensure that the bit for that layout type is set. When the
client requests attributes, send back a list of supported types.
Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
Reviewed-by: NWeston Andros Adamson <dros@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Have a simple flex file server where the mds (NFSv4.1 or NFSv4.2)
is also the ds (NFSv3). I.e., the metadata and the data file are
the exact same file.

This will allow testing of the flex file client.

Simply add the "pnfs" export option to your export
in /etc/exports and mount from a client that supports
flex files.
Signed-off-by: NTom Haynes <loghyr@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Move the existing static function to an inline helper, and call it.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

This is a simple extension to the block layout driver to use SCSI
persistent reservations for access control and fencing, as well as
SCSI VPD pages for device identification.

For this we need to pass the nfs4_client to the proc_getdeviceinfo method
to generate the reservation key, and add a new fence_client method
to allow for fence actions in the layout driver.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Split the config symbols into a generic pNFS one, which is invisible
and gets selected by the layout drivers, and one for the block layout
driver.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Have the CB_LAYOUTRECALL code treat NFS4_OK and NFS4ERR_DELAY returns
equivalently. Change the code to periodically resend CB_LAYOUTRECALLS
until the ls_layouts list is empty or the client returns a different
error code.

If we go for two lease periods without the list being emptied or the
client sending a hard error, then we give up and clean out the list
anyway.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Tested-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

We do need to serialize layout stateid morphing operations, but we
currently hold the ls_mutex across a layout recall which is pretty
ugly. It's also unnecessary -- once we've bumped the seqid and
copied it, we don't need to serialize the rest of the CB_LAYOUTRECALL
vs. anything else. Just drop the mutex once the copy is done.

This was causing a "workqueue leaked lock or atomic" warning and an
occasional deadlock.

There's more work to be done here but this fixes the immediate
regression.

Fixes: cc8a5532 "nfsd: serialize layout stateid morphing operations"
Cc: stable@vger.kernel.org
Reported-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

The nfsd4_callback_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Bruce points out that the increment of the seqid in stateids is not
serialized in any way, so it's possible for racing calls to bump it
twice and end up sending the same stateid. While we don't have any
reports of this problem it _is_ theoretically possible, and could lead
to spurious state recovery by the client.

In the current code, update_stateid is always followed by a memcpy of
that stateid, so we can combine the two operations. For better
atomicity, we add a spinlock to the nfs4_stid and hold that when bumping
the seqid and copying the stateid.
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

In order to allow the client to make a sane determination of what
happened with racing LAYOUTGET/LAYOUTRETURN/CB_LAYOUTRECALL calls, we
must ensure that the seqids return accurately represent the order of
operations. The simplest way to do that is to ensure that operations on
a single stateid are serialized.

This patch adds a mutex to the layout stateid, and locks it when
checking the layout stateid's seqid. The mutex is held over the entire
operation and released after the seqid is bumped.

Note that in the case of CB_LAYOUTRECALL we must move the increment of
the seqid and setting into a new cb "prepare" operation. The lease
infrastructure will call the lm_break callback with a spinlock held, so
and we can't take the mutex in that codepath.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NJeff Layton <jeff.layton@primarydata.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

If nfsd4_layout_setlease fails, nfsd will not put ls->ls_file.

Fix commit c5c707f9 "nfsd: implement pNFS layout recalls".
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Turns out sending out layouts to any client is a bad idea if they
can't get at the storage device, so require explicit admin action
to enable pNFS.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

With return layout as, (seg is return layout, lo is record layout)
seg->offset <= lo->offset and layout_end(seg) < layout_end(lo),
nfsd should update lo's offset to seg's end,
and,
seg->offset > lo->offset and layout_end(seg) >= layout_end(lo),
nfsd should update lo's end to seg's offset.

Fixes: 9cf514cc ("nfsd: implement pNFS operations")
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

According to RFC5661:
" When lr_returntype is LAYOUTRETURN4_FSID, the current filehandle is used
   to identify the file system and all layouts matching the client ID,
   the fsid of the file system, lora_layout_type, and lora_iomode are
   returned.  When lr_returntype is LAYOUTRETURN4_ALL, all layouts
   matching the client ID, lora_layout_type, and lora_iomode are
   returned and the current filehandle is not used. "

When returning client layouts, always check layout type.
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

31ef83dc "nfsd: add trace events" had a typo that dropped a trace
event and replaced it by an incorrect recursive call to
nfsd4_cb_layout_fail.  133d5582 "Subject: nfsd: don't recursively
call nfsd4_cb_layout_fail" fixed the crash, this restores the
tracepoint.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

Due to a merge error when creating c5c707f9 ("nfsd: implement pNFS
layout recalls"), we recursively call nfsd4_cb_layout_fail from itself,
leading to stack overflows.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Fixes:  c5c707f9 ("nfsd: implement pNFS layout recalls")
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
---
 fs/nfsd/nfs4layouts.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c
index 3c1bfa1..1028a06 100644
--- a/fs/nfsd/nfs4layouts.c
+++ b/fs/nfsd/nfs4layouts.c
@@ -587,8 +587,6 @@ nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)

 	rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));

-	nfsd4_cb_layout_fail(ls);
-
 	printk(KERN_WARNING
 		"nfsd: client %s failed to respond to layout recall. "
 		"  Fencing..\n", addr_str);
--
1.9.1

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: NChristoph 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: NChristoph 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: NChristoph 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: NChristoph Hellwig <hch@lst.de>