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>
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>
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>
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>
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>
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>
If we have a capsnap but no auth cap (e.g. because it is migrating to
another mds), bail out and do nothing for now. Do NOT remove the capsnap
from the flush list.
Signed-off-by: Sage Weil <sage@newdream.net>
The caps revocation should either initiate writeback, invalidateion, or
call check_caps to ack or do the dirty work. The primary question is
whether we can get away with only checking the auth cap or whether all
caps need to be checked.
The old code was doing...something else. At the very least, revocations
from non-auth MDSs could break by triggering the "check auth cap only"
case.
Signed-off-by: Sage Weil <sage@newdream.net>
If the file mode is marked as "lazy," perform cached/buffered reads when
the caps permit it. Adjust the rdcache_gen and invalidation logic
accordingly so that we manage our cache based on the FILE_CACHE -or-
FILE_LAZYIO cap bits.
Signed-off-by: Sage Weil <sage@newdream.net>
If we have marked a file as "lazy" (using the ceph ioctl), perform buffered
writes when the MDS caps allow it.
Signed-off-by: Sage Weil <sage@newdream.net>
Allow an application to mark a file descriptor for lazy file consistency
semantics, allowing buffered reads and writes when multiple clients are
accessing the same file.
Signed-off-by: Sage Weil <sage@newdream.net>
Also clean up the file flags -> file mode -> wanted caps functions while
we're at it. This resyncs this file with userspace.
Signed-off-by: Sage 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: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
When we embed a dentry lease release notification in a request, invalidate
our lease so we don't think we still have it. Otherwise we can get all
sorts of incorrect client behavior when multiple clients are interacting
with the same part of the namespace.
Signed-off-by: Sage Weil <sage@newdream.net>
Free the ceph_pg_mapping structs when they are removed from the pg_temp
rbtree. Also fix a leak in the __insert_pg_mapping() error path.
Signed-off-by: Sage Weil <sage@newdream.net>
We need to set the d_release dop for snapdir and snapped dentries so that
the ceph_dentry_info struct gets released. We also use the dcache to
cache readdir results when possible, which only works if we know when
dentries are dropped from the cache. Since we don't use the dcache for
readdir in the hidden snapdir, avoid that case in ceph_dentry_release.
Signed-off-by: Sage Weil <sage@newdream.net>
We should always go to the MDS for readdir on the hidden snapdir. The
set of snapshots can change at any time; the client can't trust its cache
for that.
Signed-off-by: Sage 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: Sage 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: Sage Weil <sage@newdream.net>
The buffer was too small. Make it bigger, use snprintf(), put brackets
around the ipv6 address to avoid mixing it up with the :port, and use the
ever-so-handy %pI[46] formats.
Signed-off-by: Sage Weil <sage@newdream.net>
A message can be on a queue (pending or sent), or out_msg (sending), or
both. We were assuming that if it's not on a queue it couldn't be out_msg,
but that was false in the case of lossy connections like the OSD. Fix
ceph_con_revoke() to treat these cases independently. Also, fix the
out_kvec_is_message check to only trigger if we are currently sending
_this_ message.
This fixes a GPF in tcp_sendpage, triggered by OSD restarts.
Signed-off-by: Sage Weil <sage@newdream.net>
We need to increase the total and used counters when allocating a new cap
in the non-reserved (cap import) case.
Signed-off-by: Sage Weil <sage@newdream.net>
We can drop caps with an mds request. Ensure we only drop unused AND
clean caps, since the MDS doesn't support cap writeback in that context,
nor do we track it. If caps are dirty, and the MDS needs them back, we
it will revoke and we will flush in the normal fashion.
This fixes a possibly loss of metadata.
Signed-off-by: Sage Weil <sage@newdream.net>
We may not recurse for CHOOSE_LEAF if we start with a leaf node. When
that happens, the out2 vector needs to be filled in with the result.
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>
Handle a splice_dentry failure (due to a d_materialize_unique error)
without crashing. (Also, report the error code.)
Signed-off-by: Sage Weil <sage@newdream.net>
If the incremental osdmap has a new crush map, advance the position after
decoding so that we can parse the rest of the osdmap properly.
Signed-off-by: Sage Weil <sage@newdream.net>
We need to properly initialize skip, as not all alloc_msg op instances
set it.
Also, BUG if someone says skip but also allocates a message.
Signed-off-by: Sage 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: Sage 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: Sage Weil <sage@newdream.net>
bdi_seq is an atomic_long_t but we're using ATOMIC_INIT, which causes
build failures on ia64. This patch fixes it to use ATOMIC_LONG_INIT.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>
We were setting f_namelen in kstatfs to PATH_MAX instead of NAME_MAX.
That disagrees with ceph_lookup behavior (which checks against NAME_MAX),
and also makes the pjd posix test suite spit out ugly errors because with
can't clean up its temporary files.
Signed-off-by: Sage Weil <sage@newdream.net>
We misused list_move_tail() to order the dentry in d_subdirs.
This will screw up the d_subdirs order.
This bug can be reliably reproduced by:
1. mount ceph fs.
2. on ceph fs, git clone git://ceph.newdream.net/git/ceph.git
3. Run autogen.sh in ceph directory.
(Note: Errors only occur at the first time you run autogen.sh.)
Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: clean up on forwarded aborted mds request
ceph: fix leak of osd authorizer
ceph: close out mds, osd connections before stopping auth
ceph: make lease code DN specific
fs/ceph: Use ERR_CAST
ceph: renew auth tickets before they expire
ceph: do not resend mon requests on auth ticket renewal
ceph: removed duplicated #includes
ceph: avoid possible null dereference
ceph: make mds requests killable, not interruptible
sched: add wait_for_completion_killable_timeout
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: Sage Weil <sage@newdream.net>
The auth module (part of the mon_client) is needed to free any
ceph_authorizer(s) used by the mds and osd connections. Flush the msgr
workqueue before stopping monc to ensure that the destroy_authorizer
auth op is available when those connections are closed out.
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>
Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more
clear what is the purpose of the operation, which otherwise looks like a
no-op.
In the case of fs/ceph/inode.c, ERR_CAST is not needed, because the type of
the returned value is the same as the type of the enclosing function.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
type T;
T x;
identifier f;
@@
T f (...) { <+...
- ERR_PTR(PTR_ERR(x))
+ x
...+> }
@@
expression x;
@@
- ERR_PTR(PTR_ERR(x))
+ ERR_CAST(x)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Sage Weil <sage@newdream.net>
We were only requesting renewal after our tickets expire; do so before
that. Most of the low-level logic for this was already there; just use
it.
Signed-off-by: Sage Weil <sage@newdream.net>
We only want to send pending mon requests when we successfully
authenticate. If we are already authenticated, like when we renew our
ticket, there is no need to resend pending requests.
Signed-off-by: Sage Weil <sage@newdream.net>
fs/ceph/auth.c: linux/slab.h is included more than once.
fs/ceph/super.h: linux/slab.h is included more than once.
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Sage Weil <sage@newdream.net>
ac->ops may be null; use protocol id in error message instead.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (59 commits)
ceph: reuse mon subscribe message instead of allocated anew
ceph: avoid resending queued message to monitor
ceph: Storage class should be before const qualifier
ceph: all allocation functions should get gfp_mask
ceph: specify max_bytes on readdir replies
ceph: cleanup pool op strings
ceph: Use kzalloc
ceph: use common helper for aborted dir request invalidation
ceph: cope with out of order (unsafe after safe) mds reply
ceph: save peer feature bits in connection structure
ceph: resync headers with userland
ceph: use ceph. prefix for virtual xattrs
ceph: throw out dirty caps metadata, data on session teardown
ceph: attempt mds reconnect if mds closes our session
ceph: clean up send_mds_reconnect interface
ceph: wait for mds OPEN reply to indicate reconnect success
ceph: only send cap releases when mds is OPEN|HUNG
ceph: dicard cap releases on mds restart
ceph: make mon client statfs handling more generic
ceph: drop src address(es) from message header [new protocol feature]
...
Use the same message, allocated during startup. No need to reallocate a
new one each time around (and potentially ENOMEM).
Signed-off-by: Sage Weil <sage@newdream.net>
Now that the last user passing a NULL file pointer is gone we can remove
the redundant dentry argument and associated hacks inside vfs_fsynmc_range.
The next step will be removig the dentry argument from ->fsync, but given
the luck with the last round of method prototype changes I'd rather
defer this until after the main merge window.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The auth_reply handler will (re)send any pending requests. For the
initial mon authenticate phase, that's correct, but when a auth ticket
renewal races with an in-flight request, we may resend a request message
that is already in flight. Avoid this by revoking the message before
sending it.
We should also avoid resending requests at all during ticket renewal; that
will come soon.
Signed-off-by: Sage 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: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Sage 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: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Specify max bytes in request to bound size of reply. Add associated
mount option with default value of 512 KB.
Signed-off-by: Sage Weil <sage@newdream.net>
Use kzalloc rather than the combination of kmalloc and memset.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression x,size,flags;
statement S;
@@
-x = kmalloc(size,flags);
+x = kzalloc(size,flags);
if (x == NULL) S
-memset(x, 0, size);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Sage 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: Sage Weil <sage@newdream.net>
The remove_session_caps() helper is called when an MDS closes out our
session (either normally, or as a result of a failed reconnect), and when
we tear down state for umount. If we remove the last cap, and there are
no cap migrations in progress, then there is little hope of us flushing
out that data to the mds (without heroic efforts to reconnect and flush).
So, to avoid leaving inodes pinned (due to dirty state) and crashing after
umount, throw out dirty caps state and unpin the inodes. Print a warning
to the console so we know something was lost.
NOTE: Although we drop wrbuffer refs, we don't actually mark pages clean;
maybe a truncate should be queued?
Signed-off-by: Sage Weil <sage@newdream.net>
Currently, if our session is closed (due to a timeout, or explicit close,
or whatever), we just sit there doing nothing unless/until the MDS
restarts, at which point we try to reconnect.
Change client to attempt an immediate reconnect if our session is closed.
Note that currently the MDS doesn't support this, and our attempt will
fail. We'll get a session CLOSE, our caps and dirty cap state will be
dropped, and the client will be free to attempt to reconnect. That's
clearly not as nice as a successful reconnect, but it at least allows us
to try to carry on, and in the future the MDS will support a reconnect
and we will fare better.
Signed-off-by: Sage Weil <sage@newdream.net>
Pass a ceph_mds_session, since the caller has it.
Remove the dead code for sending empty reconnects. It used to be used
when the MDS contacted _us_ to solicit a reconnect, and we could reply
saying "go away, I have no session." Now we only send reconnects based
on the mds map, and only when we do in fact have an open session.
Signed-off-by: Sage Weil <sage@newdream.net>
We used to infer reconnect success by watching the MDS state, essentially
assuming that hearing nothing meant things were ok. That wasn't
particularly reliable. Instead, the MDS replies with an explicit OPEN
message to indicate success.
Strictly speaking, this is a protocol change, but it is a backwards
compatible one that does not break new clients + old servers or old
clients + new servers. At least not yet.
Drop unused @all argument from kick_requests while we're at it.
Signed-off-by: Sage Weil <sage@newdream.net>
On OPENING we shouldn't have any caps (or releases).
On CLOSING, we should wait until we succeed (and throw it all out), or
don't (and are OPEN again).
On RECONNECTING we can wait until we are OPEN.
Signed-off-by: Sage Weil <sage@newdream.net>
If the MDS restarts, the expire caps state is no longer shared, and can be
thrown out. Caps state will be rebuilt on the MDS during the reconnect
process that follows. Zero out any release messages and adjust the
release counter accordingly.
Signed-off-by: Sage Weil <sage@newdream.net>
This is being done so that we could reuse the statfs
infrastructure with other requests that return values.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
The CEPH_FEATURE_NOSRCADDR protocol feature avoids putting the full source
address in each message header (twice). This patch switches the client to
the new scheme, and _requires_ this feature on the server. The server
will support both the old and new schemes. That means an old client will
work with a new server, but a new client will not work with an old server.
Signed-off-by: Sage Weil <sage@newdream.net>
The bdi_setup_and_register() helper doesn't help us since we bdi_init() in
create_client() and bdi_register() only when sget() succeeds.
Signed-off-by: Sage Weil <sage@newdream.net>
We want to assign an offset when the dentry goes from null to linked, which
is always done by splice_dentry(). Notably, we should NOT assign an
offset when a dentry is first created and is still null.
BUG if we try to splice a non-null dentry (we shouldn't).
Signed-off-by: Sage Weil <sage@newdream.net>
If the version hasn't changed, don't rebuild the index.
Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
If we use the xattr_blob, clear the pointer so we don't release the memory
at the bottom of the fuction.
Reported-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Simplify messenger locking, and close race between ceph_con_close() setting
the CLOSED bit and con_work() checking the bit, then taking the mutex.
Signed-off-by: Sage Weil <sage@newdream.net>
d_obtain_alias() doesn't return NULL, it returns an ERR_PTR().
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
We only need to pass in front_len. Callers can attach any other payload
pieces (middle, data) as they see fit.
Signed-off-by: Sage Weil <sage@newdream.net>
Returning ERR_PTR(-ENOMEM) is useless extra work. Return NULL on failure
instead, and fix up the callers (about half of which were wrong anyway).
Signed-off-by: Sage Weil <sage@newdream.net>
Since we don't need to maintain large pools of messages, we can just
use the standard mempool_t. We maintain a msgpool 'wrapper' because we
need the mempool_t* in the alloc function, and mempool gives us only
pool_data.
Signed-off-by: Sage Weil <sage@newdream.net>
ceph_sb_to_client and ceph_client are really identical, we need to dump
one; while function ceph_client is confusing with "struct ceph_client",
ceph_sb_to_client's definition is more clear; so we'd better switch all
call to ceph_sb_to_client.
-static inline struct ceph_client *ceph_client(struct super_block *sb)
-{
- return sb->s_fs_info;
-}
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
This would only trigger if we bailed out before resetting r_con_filling_msg
because the server reply was corrupt (oversized).
Signed-off-by: Sage Weil <sage@newdream.net>
"xattr" is never NULL here. We took care of that in the previous
if statement block.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Following Nick Piggin patches in btrfs, pagecache pages should be
allocated with __page_cache_alloc, so they obey pagecache memory
policies.
Also, using add_to_page_cache_lru instead of using a private
pagevec where applicable.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
If we abort a request, we return to caller, but the request may still
complete. And if we hold the dir FILE_EXCL bit, we may not release a
lease when sending a request. A simple un-tar, control-c, un-tar again
will reproduce the bug (manifested as a 'Cannot open: File exists').
Ensure we invalidate affected dentry leases (as well dir I_COMPLETE) so
we don't have valid (but incorrect) leases. Do the same, consistently, at
other sites where I_COMPLETE is similarly cleared.
Signed-off-by: Sage Weil <sage@newdream.net>
When we abort requests we need to prevent fill_trace et al from doing
anything that relies on locks held by the VFS caller. This fixes a race
between the reply handler and the abort code, ensuring that continue
holding the dir mutex until the reply handler completes.
Signed-off-by: Sage Weil <sage@newdream.net>
