The snap_seq field in an rbd_image_header structure held the value
from the rbd image header when it was last refreshed.  We now
maintain this value in the snapc->seq field.  So get rid of the
other one.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

In rbd_header_add_snap() there is code to set snapc->seq to the
just-added snapshot id.  This is the only remnant left of the
use of that field for recording which snapshot an rbd_dev was
associated with.  That functionality is no longer supported,
so get rid of that final bit of code.

Doing so means we never actually set snapc->seq any more.  On the
server, the snapshot context's sequence value represents the highest
snapshot id ever issued for a particular rbd image.  So we'll make
it have that meaning here as well.  To do so, set this value
whenever the rbd header is (re-)read.  That way it will always be
consistent with the rest of the snapshot context we maintain.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

In rbd_header_set_snap(), there is logic to make the snap context's
seq field get set to a particular snapshot id, or 0 if there is no
snapshot for the rbd image.

This seems to be an artifact of how the current snapshot id for an
rbd_dev was recorded before the rbd_dev->snap_id field began to be
used for that purpose.

There's no need to update the value of snapc->seq here any more, so
stop doing it.  Tidy up a few local variables in that function
while we're at it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

In what appears to be an artifact of a different way of encoding
whether an rbd image maps a snapshot, __rbd_refresh_header() has
code that arranges to update the seq value in an rbd image's
snapshot context to point to the first entry in its snapshot
array if that's where it was pointing initially.

We now use rbd_dev->snap_id to record the snapshot id--using the
special value CEPH_NOSNAP to indicate the rbd_dev is not mapping a
snapshot at all.

There is therefore no need to check for this case, nor to update the
seq value, in __rbd_refresh_header().  Just preserve the seq value
that rbd_read_header() provides (which, at the moment, is nothing).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Previously the original header version was sent. Now, we update it
when the header changes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>

This prevents a race between requests with a given snap context and
header updates that free it. The osd client was already expecting the
snap context to be reference counted, since it get()s it in
ceph_osdc_build_request and put()s it when the request completes.

Also remove the second down_read()/up_read() on header_rwsem in
rbd_do_request, which wasn't actually preventing this race or
protecting any other data.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>

The image may have been resized.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>

If an image was mapped to a snapshot, the size of the head version
would be shown. Protect capacity with header_rwsem, since it may
change.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>

Snapshots cannot be resized, and the new capacity of head should not
be reflected by the snapshot.
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

When a snapshot is deleted, the OSD will return ENOENT when reading
from it. This is normally interpreted as a hole by rbd, which will
return zeroes. To minimize the time in which this can happen, stop
requests early when we are notified that our snapshot no longer
exists.

[elder@inktank.com: updated __rbd_init_snaps_header() logic]
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

This is a trivial fix for the debug output, as it is inconsistent
with the function name so may confuse people when debugging.

[elder@inktank.com: switched to use __func__]
Signed-off-by: Jiaju Zhang <jjzhang@suse.de>
Reviewed-by: Alex Elder <elder@inktank.com>

We re-run the loop but we don't re-set the attrs pointer back to NULL.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Reviewed-by: Alex Elder <elder@inktank.com>

We exponentially back off when we encounter connection errors.  If several
errors accumulate, we will eventually wait ages before even trying to
reconnect.

Fix this by resetting the backoff counter after a successful negotiation/
connection with the remote node.  Fixes ceph issue #2802.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

Take the con mutex while we are initiating a ceph open.  This is necessary
because the may have previously been in use and then closed, which could
result in a racing workqueue running con_work().
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>

When we detect a mds session reset, close the old ceph_connection before
reopening it.  This ensures we clean up the old socket properly and keep
the ceph_connection state correct.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

Previously, we were opportunistically initializing the bio_iter if it
appeared to be uninitialized in the middle of the read path.  The problem
is that a sequence like:

 - start reading message
 - initialize bio_iter
 - read half a message
 - messenger fault, reconnect
 - restart reading message
 - ** bio_iter now non-NULL, not reinitialized **
 - read past end of bio, crash

Instead, initialize the bio_iter unconditionally when we allocate/claim
the message for read.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

The linger op registration (i.e., watch) modifies the object state.  As
such, the OSD will reply with success if it has already applied without
doing the associated side-effects (setting up the watch session state).
If we lose the ACK and resubmit, we will see success but the watch will not
be correctly registered and we won't get notifies.

To fix this, always resubmit the linger op with a new tid.  We accomplish
this by re-registering as a linger (i.e., 'registered') if we are not yet
registered.  Then the second loop will treat this just like a normal
case of re-registering.

This mirrors a similar fix on the userland ceph.git, commit 5dd68b95, and
ceph bug #2796.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

Hold the mutex while twiddling all of the state bits to avoid possible
races.  While we're here, make not of why we cannot close the socket
directly.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

We need to set error_msg to something useful before calling ceph_fault();
do so here for try_{read,write}().  This is more informative than

libceph: osd0 192.168.106.220:6801 (null)
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

The server side recently added support for tuning some magic
crush variables. Decode these variables if they are present, or use the
default values if they are not present.

Corresponds to ceph.git commit 89af369c25f274fe62ef730e5e8aad0c54f1e5a5.
Signed-off-by: caleb miles <caleb.miles@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

This is simply cleanup that will keep things more closely synced with the
userland code.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>

Several functions include a num_reply parameter, but it is never
used.  Just get rid of it everywhere--it seems to be something
that never got fully implemented.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Use the name "ceph_opts" consistently (rather than just "opt") for
pointers to a ceph_options structure.

Change the few spots that don't use "rbd_opts" for a rbd_options
pointer to match the rest.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Rename variables named "obj" which represent object names so they're
consistently named "object_name".

Rename the "cls" and "method" parameters in rbd_req_sync_exec()
to be "class_name" and "method_name", and make similar changes
to the names of local variables in that function representing
the lengths of those names.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

An rbd image is not a single object, but a logical construct made up
of an aggregation of objects.

Rename some fields in struct rbd_dev, in hopes of reinforcing this.
    obj         --> image_name
    obj_len     --> image_name_len
    obj_md_name --> header_name
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Most variables that represent a struct rbd_device are named
"rbd_dev", but in some cases "dev" is used instead.  Change all the
"dev" references so they use "rbd_dev" consistently, to make it
clear from the name that we're working with an RBD device (as
opposed to, for example, a struct device).  Similarly, change the
name of the "dev" field in struct rbd_notify_info to be "rbd_dev".
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is no need to impose a small limit the length of the snapshot
name recorded for an rbd image in a struct rbd_dev.  Remove the
limitation by allocating space for the snapshot name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is no need to impose a small limit the length of the rbd image
name recorded in a struct rbd_dev.  Remove the limitation by
allocating space for the image name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is no need to impose a small limit the length of the header
name recorded for an rbd image in a struct rbd_dev.  Remove the
limitation by allocating space for the header name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is no need to impose a small limit the length of the object
prefix recorded for an rbd image in a struct rbd_image_header.
Remove the limitation by allocating space for the object prefix
dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is no need to impose a small limit the length of the pool name
recorded for an rbd image in a struct rbd_device.  Remove the
limitation by allocating space for the pool name ynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Add an entry under /sys/bus/rbd/devices/<N>/ named "pool_id" that
provides the id for the pool the rbd image is assocatied with.  This
is in addition to the pool name already provided.

Rename the "poolid" field in struct rbd_device  to be "pool_id".

Update the documentation to reflect the addition of this new entry.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Each rbd image has a name that forms the basis of all data objects
backing the device.  Old (format 1) images refer to this name as the
"block name," while new (format 2) images use the term "object
prefix" for this.

Change the field name in the in-core rbd image header structure to
reflect the more modern usage.  We intentionally keep the the name
"block_name" in the on-disk definition for format 1 image headers.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

Define a new function dup_token(), to be used during argument
parsing for making dynamically-allocated copies of tokens being
parsed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

This adds a new utility routine which will return a dynamically-
allocated buffer containing a string that has been decoded from ceph
over-the-wire format.  It also returns the length of the string
if the address of a size variable is supplied to receive it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

In rbd_req_sync_notify_ack(), a local variable was needlessly being
used to hold a null pointer.  Just pass NULL instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

There is a BUG_ON() call that doesn't account for the single byte
structure version at the start of an encoded filepath in
ceph_encode_filepath().  Fix that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

d_parent is never NULL, and IS_ROOT() is the proper way to check for a
(non-self-referential) parent.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>

Add an atomic variable 'stopping' as flag in struct ceph_messenger,
set this flag to 1 in function ceph_destroy_client(), and add the condition code
in function ceph_data_ready() to test the flag value, if true(1), just return.
Signed-off-by: Guanjun He <gjhe@suse.com>
Reviewed-by: Sage Weil <sage@inktank.com>

In ancient times, the messenger could both initiate and accept connections.
An artifact if that was data structures to store/process an incoming
ceph_msg_connect request and send an outgoing ceph_msg_connect_reply.
Sadly, the negotiation code was referencing those structures and ignoring
important information (like the peer's connect_seq) from the correct ones.

Among other things, this fixes tight reconnect loops where the server sends
RETRY_SESSION and we (the client) retries with the same connect_seq as last
time.  This bug pretty easily triggered by injecting socket failures on the
MDS and running some fs workload like workunits/direct_io/test_sync_io.
Signed-off-by: Sage Weil <sage@inktank.com>