Ignore replication or auth frag data if it indicates an MDS that is not
active.  This can happen if the MDS shuts down and the client has stale
data about the namespace distribution across the MDS cluster.  If that's
the case, fall back to directing the request based on the auth cap (which
should always be accurate).
Signed-off-by: NSage Weil <sage@newdream.net>

Associate request with sessions that aren't yep open.  This makes the
debugfs mdsc request list more informative.
Signed-off-by: NSage Weil <sage@newdream.net>

The r_mds field is redundant, since we can find the same information at
r_session->s_mds, and when r_session is NULL then r_mds is meaningless.
Signed-off-by: NSage Weil <sage@newdream.net>

This implements the DIRLAYOUTHASH protocol feature, which passes the dir
layout over the wire from the MDS.  This gives the client knowledge
of the correct hash function to use for mapping dentries among dir
fragments.

Note that if this feature is _not_ present on the client but is on the
MDS, the client may misdirect requests.  This will result in a forward
and degrade performance.  It may also result in inaccurate NFS filehandle
generation, which will prevent fh resolution when the inode is not present
in the client cache and the parent directories have been fragmented.
Signed-off-by: NSage Weil <sage@newdream.net>

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: NNick Piggin <npiggin@kernel.dk>

Previously the kernel client incorrectly assumed everything was a directory.
Signed-off-by: NHerb Shiu <herb_shiu@tcloudcomputing.com>
Acked-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

MDS requests can be rebuilt and resent in non-process context, but were
filling in uid/gid from current_fsuid/gid.  Put that information in the
request struct on request setup.

This fixes incorrect (and root) uid/gid getting set for requests that
are forwarded between MDSs, usually due to metadata migrations.
Signed-off-by: NSage Weil <sage@newdream.net>

Switch from using the BKL explicitly to the new lock_flocks() interface.
Eventually this will turn into a spinlock.
Signed-off-by: NSage Weil <sage@newdream.net>

When the lock_kernel() turns into lock_flocks() and a spinlock, we won't
be able to do allocations with the lock held.  Preallocate space without
the lock, and retry if the lock state changes out from underneath us.
Signed-off-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph.  This
is mostly a matter of moving files around.  However, a few key pieces
of the interface change as well:

 - ceph_client becomes ceph_fs_client and ceph_client, where the latter
   captures the mon and osd clients, and the fs_client gets the mds client
   and file system specific pieces.
 - Mount option parsing and debugfs setup is correspondingly broken into
   two pieces.
 - The mon client gets a generic handler callback for otherwise unknown
   messages (mds map, in this case).
 - The basic supported/required feature bits can be expanded (and are by
   ceph_fs_client).

No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.
Signed-off-by: NSage Weil <sage@newdream.net>

Fix the reconnect encoding to encode the cap record when the MDS does not
have the FLOCK capability (i.e., pre v0.22).
Signed-off-by: NSage Weil <sage@newdream.net>

We are in a position to return an error; do that instead.
Signed-off-by: NSage Weil <sage@newdream.net>

When making a request in the virtual snapdir or a snapped portion of the
namespace, we should choose the MDS based on the first nonsnap parent (and
its caps).  If that is not the best place, we will get forward hints to
find the right MDS in the cluster.  This fixes ESTALE errors when using
the .snap directory and namespace with multiple MDSs.
Signed-off-by: NSage Weil <sage@newdream.net>

The use of a completion when waiting for session shutdown during umount is
inappropriate, given the complexity of the condition.  For multiple MDS's,
this resulted in the umount thread spinning, often preventing the session
close message from being processed in some cases.

Switch to a waitqueue and defined a condition helper.  This cleans things
up nicely.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

Implement flock inode operation to support advisory file locking.  All
lock/unlock operations are synchronous with the MDS.  Lock state is
sent when reconnecting to a recovering MDS to restore the shared lock
state.
Signed-off-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Encode either old or v2 encoding of client_reconnect message, depending on
whether the peer has the FLOCK feature bit.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NGreg Farnum <gregf@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

When we get a cap EXPORT message, make sure we are connected to all export
targets to ensure we can handle the matching IMPORT.
Signed-off-by: NSage Weil <sage@newdream.net>

If an MDS we are talking to may have failed, we need to open sessions to
its potential export targets to ensure that any in-progress migration that
may have involved some of our caps is properly handled.
Signed-off-by: NSage Weil <sage@newdream.net>

There are a few cases where we need to open sessions with a given mds's
potential export targets.
Signed-off-by: NSage Weil <sage@newdream.net>

Caps related accounting is now being done per mds client instead
of just being global. This prepares ground work for a later revision
of the caps preallocated reservation list.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

No functional change, aside from more useful debug output.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>

This fixes an issue triggered by running concurrent syncs. One of the syncs
would go through while the other would just hang indefinitely. In any case, we
never actually want to wake a single waiter, so the *_all functions should
be used.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

Strip the cap and dentry releases from replayed messages.  They can
cause the shared state to get out of sync because they were generated
(with the request message) earlier, and no longer reflect the current
client state.
Signed-off-by: NSage Weil <sage@newdream.net>

Replayed rename operations (after an mds failure/recovery) were broken
because the request paths were regenerated from the dentry names, which
get mangled when d_move() is called.

Instead, resend the previous request message when replaying completed
operations.  Just make sure the REPLAY flag is set and the target ino is
filled in.

This fixes problems with workloads doing renames when the MDS restarts,
where the rename operation appears to succeed, but on mds restart then
fails (leading to client confusion, app breakage, etc.).
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes a race between handle_reply finishing an mds request, signalling
completion, and then dropping the request structing and its dentry+inode
refs, and pre_umount function waiting for requests to finish before
letting the vfs tear down the dcache.  If umount was delayed waiting for
mds requests, we could race and BUG in shrink_dcache_for_umount_subtree
because of a slow dput.

This delays umount until the msgr queue flushes, which means handle_reply
will exit and will have dropped the ceph_mds_request struct.  I'm assuming
the VFS has already ensured that its calls have all completed and those
request refs have thus been dropped as well (I haven't seen that race, at
least).
Signed-off-by: NSage Weil <sage@newdream.net>

If we have enough memory to allocate a new cap release message, do so, so
that we can send a partial release message immediately.  This keeps us from
making the MDS wait when the cap release it needs is in a partially full
release message.

If we fail because of ENOMEM, oh well, they'll just have to wait a bit
longer.
Signed-off-by: NSage Weil <sage@newdream.net>

If we get an IMPORT that give us a cap, but we don't have the inode, queue
a release (and try to send it immediately) so that the MDS doesn't get
stuck waiting for us.
Signed-off-by: NSage Weil <sage@newdream.net>

If the client revokes a lease with a higher seq than what we have, keep
the mds's seq, so that it honors our release.  Otherwise, we can hang
indefinitely.
Signed-off-by: NSage Weil <sage@newdream.net>

If an mds request is aborted (timeout, SIGKILL), it is left registered to
keep our state in sync with the mds.  If we get a forward notification,
though, we know the request didn't succeed and we can unregister it
safely.  We were trying to resend it, but then bailing out (and not
unregistering) in __do_request.
Signed-off-by: NSage Weil <sage@newdream.net>

The lease code includes a mask in the CEPH_LOCK_* namespace, but that
namespace is changing, and only one mask (formerly _DN == 1) is used, so
hard code for that value for now.

If we ever extend this code to handle leases over different data types we
can extend it accordingly.
Signed-off-by: NSage Weil <sage@newdream.net>

The underlying problem is that many mds requests can't be restarted.  For
example, a restarted create() would return -EEXIST if the original request
succeeds.  However, we do not want a hung MDS to hang the client too.  So,
use the _killable wait_for_completion variants to abort on SIGKILL but
nothing else.
Signed-off-by: NSage Weil <sage@newdream.net>

The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NSage Weil <sage@newdream.net>

This is essential, as for the rados block device we'll need
to run in different contexts that would need flags that
are other than GFP_NOFS.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

We invalidate I_COMPLETE and dentry leases in two places: on aborted mds
request and on request replay.  Use common helper to avoid duplicate code.
Signed-off-by: NSage Weil <sage@newdream.net>

Signed-off-by: NSage Weil <sage@newdream.net>