We used to use i_head_snapc to keep track of which snapc the current epoch
of dirty data was dirtied under.  It is used by queue_cap_snap to set up
the cap_snap.  However, since we queue cap snaps for any dirty caps, not
just for dirty file data, we need to keep a valid i_head_snapc anytime
we have dirty|flushing caps.  This fixes a NULL pointer deref in
queue_cap_snap when writing back dirty caps without data (e.g.,
snaptest-authwb.sh).
Signed-off-by: Sage Weil <sage@newdream.net>

Fix argument order.  We want to move the item to the end of the list, not
change the position of the head.
Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>

If we hold the EXCL cap, we cannot trust the dir stats from the MDS (num
files, subdirs) and must not incorrectly conclude that the directory is
empty.  If we do, we get can bad results from lookup (bad ENOENT) and
bad readdir results.
Signed-off-by: Sage Weil <sage@newdream.net>

This allows code outside of the mm core to safely manipulate page state
and not worry about the other accounting. Not using these routines means
that some code will lose track of the accounting and we get bugs. This
has happened once already.
Signed-off-by: Michael Rubin <mrubin@google.com>
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>

When a realm is updated, we need to queue writeback on inodes in that
realm _and_ its children.  Otherwise, if the inode gets cowed on the
server, we can get a hang later due to out-of-sync cap/snap state.
Signed-off-by: Sage Weil <sage@newdream.net>

When we snapshot dirty metadata that needs to be written back to the MDS,
include dirty xattr metadata.  Make the capsnap reference the encoded
xattr blob so that it will be written back in the FLUSHSNAP op.

Also fix the capsnap creation guard to include dirty auth or file bits,
not just tests specific to dirty file data or file writes in progress
(this fixes auth metadata writeback).
Signed-off-by: Sage Weil <sage@newdream.net>

We should include the xattr metadata blob in the cap update message any
time we are flushing dirty state, NOT just when we are also dropping the
cap.  This fixes async xattr writeback.

Also, clean up the code slightly to avoid duplicating the bit test.
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>

Generalize the current statfs synchronous requests, and support pool_ops.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

Normally, if the Fb cap bit is being revoked, we queue an async writeback.
If there is no dirty data but we still hold the cap, this leaves the
client sitting around doing nothing until the cap timeouts expire and the
cap is released on its own (as it would have been without the revocation).

Instead, only queue writeback if the bit is actually used (i.e., we have
dirty data).  If not, we can reply to the revocation immediately.
Signed-off-by: Sage Weil <sage@newdream.net>

Actually apply the mount option to the mount_args struct.
Signed-off-by: Sage Weil <sage@newdream.net>

This makes checkpatch happy.
Signed-off-by: Sage Weil <sage@newdream.net>

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

Define the MDS operations and data types for doing file advisory locking
with the MDS.
Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

This informs the server that we will accept v2 client_caps format and v2
client_reconnect format messages.
Signed-off-by: Greg Farnum <gregf@hq.newdream.net>
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>

Add support for v2 encoding of MClientCaps, which includes a flock blob.
Signed-off-by: Sage Weil <sage@newdream.net>

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

The pool info contains a vector for snap_info_t, not snap ids.  This fixes
the broken decoding, which would declare teh update corrupt when a pool
snapshot was created.
Signed-off-by: Sage Weil <sage@newdream.net>

The ->sync_fs() super op only needs to wait if wait is true.  Otherwise,
just get some dirty cap writeback started.
Signed-off-by: Sage Weil <sage@newdream.net>

Well, this Shouldn't Happen, so it would be helpful to know the caller when
it does.
Signed-off-by: Sage Weil <sage@newdream.net>

Include the crush_ruleset in the error message.
Signed-off-by: Sage Weil <sage@newdream.net>

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

Define ROLLBACK op, IFLOCK inode lock (for advisory file locking).
Signed-off-by: Sage Weil <sage@newdream.net>

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

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

Specify the supported/required feature bits in super.h client code instead
of using the definitions from the shared kernel/userspace headers (which
will go away shortly).
Signed-off-by: Sage Weil <sage@newdream.net>

Specify the fsid mount option in hex, not via the major/minor u64 hackery we had
before.
Signed-off-by: Sage Weil <sage@newdream.net>

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

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

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

Setting it elsewhere is unnecessary and more fragile.
Signed-off-by: Sage 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: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

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

Mainly fixing minor issues reported by sparse.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>