Commit Graph

323422 Commits

Author SHA1 Message Date
Alex Elder
4fb5d67139 rbd: add warning messages for missing arguments
Tell the user (via dmesg) what was wrong with the arguments provided
via /sys/bus/rbd/add.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
2013-01-17 14:10:21 -06:00
Alex Elder
06ecc6cbf7 rbd: define and use rbd_warn()
Define a new function rbd_warn() that produces a boilerplate warning
message, identifying in the resulting message the affected rbd
device in the best way available.  Use it in a few places that now
use pr_warning().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:09:29 -06:00
Alex Elder
dd5f049dbd ceph: define ceph_encode_8_safe()
It's kind of a silly macro, but ceph_encode_8_safe() is the only one
missing from an otherwise pretty complete set.  It's not used, but
neither are a couple of the others in this set.

While in there, insert some whitespace to tidy up the alignment of
the line-terminating backslashes in some of the macro definitions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
2013-01-17 14:09:08 -06:00
Alex Elder
4caf35f9ec rbd: use kmemdup()
This replaces two kmalloc()/memcpy() combinations with a single
call to kmemdup().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:09:00 -06:00
Alex Elder
979ed480a2 rbd: kill rbd_spec->image_id_len
There is no real benefit to keeping the length of an image id, so
get rid of it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:08:54 -06:00
Alex Elder
69e7a02f63 rbd: kill rbd_spec->image_name_len
There may have been a benefit to hanging on to the length of an
image name before, but there is really none now.  The only time it's
used is when probing for rbd images, so we can just compute the
length then.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:08:46 -06:00
Alex Elder
c66c6e0c0b rbd: document rbd_spec structure
I promised Josh I would document whether there were any restrictions
needed for accessing fields of an rbd_spec structure.  This adds a
big block of comments that documents the structure and how it is
used--including the fact that we don't attempt to synchronize access
to it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:07:50 -06:00
Alex Elder
c3acb18196 libceph: reformat __reset_osd()
Reformat __reset_osd() into three distinct blocks of code
handling the three return cases.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2013-01-17 14:07:44 -06:00
Sage Weil
7d7c1f6136 crush: avoid recursion if we have already collided
This saves us some cycles, but does not affect the placement result at
all.

This corresponds to ceph.git commit 4abb53d4f.

Signed-off-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:39 -06:00
Jim Schutt
1604f488ac libceph: for chooseleaf rules, retry CRUSH map descent from root if leaf is failed
Add libceph support for a new CRUSH tunable recently added to Ceph servers.

Consider the CRUSH rule
  step chooseleaf firstn 0 type <node_type>

This rule means that <n> replicas will be chosen in a manner such that
each chosen leaf's branch will contain a unique instance of <node_type>.

When an object is re-replicated after a leaf failure, if the CRUSH map uses
a chooseleaf rule the remapped replica ends up under the <node_type> bucket
that held the failed leaf.  This causes uneven data distribution across the
storage cluster, to the point that when all the leaves but one fail under a
particular <node_type> bucket, that remaining leaf holds all the data from
its failed peers.

This behavior also limits the number of peers that can participate in the
re-replication of the data held by the failed leaf, which increases the
time required to re-replicate after a failure.

For a chooseleaf CRUSH rule, the tree descent has two steps: call them the
inner and outer descents.

If the tree descent down to <node_type> is the outer descent, and the descent
from <node_type> down to a leaf is the inner descent, the issue is that a
down leaf is detected on the inner descent, so only the inner descent is
retried.

In order to disperse re-replicated data as widely as possible across a
storage cluster after a failure, we want to retry the outer descent. So,
fix up crush_choose() to allow the inner descent to return immediately on
choosing a failed leaf.  Wire this up as a new CRUSH tunable.

Note that after this change, for a chooseleaf rule, if the primary OSD
in a placement group has failed, choosing a replacement may result in
one of the other OSDs in the PG colliding with the new primary.  This
requires that OSD's data for that PG to need moving as well.  This
seems unavoidable but should be relatively rare.

This corresponds to ceph.git commit 88f218181a9e6d2292e2697fc93797d0f6d6e5dc.

Signed-off-by: Jim Schutt <jaschut@sandia.gov>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:39 -06:00
Yan, Zheng
390306c38d ceph: check mds_wanted for imported cap
The MDS may have incorrect wanted caps after importing caps. So the
client should check the value mds has and send cap update if necessary.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
66f58691c5 ceph: allocate cap_release message when receiving cap import
When client wants to release an imported cap, it's possible there
is no reserved cap_release message in corresponding mds session.
so __queue_cap_release causes kernel panic.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
395c312b9c ceph: allow revoking duplicated caps issued by non-auth MDS
Allow revoking duplicated caps issued by non-auth MDS if these caps
are also issued by auth MDS.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:38 -06:00
Yan, Zheng
8a92a119b2 ceph: move dirty inode to migrating list when clearing auth caps
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:37 -06:00
Yan, Zheng
a41bad1a9b ceph: re-calculate truncate_size for strip object
Otherwise osd may truncate the object to larger size.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:37 -06:00
Sam Lang
6e8575faa8 ceph: Check for created flag in response from mds
The mds now sends back a created inode if the create request
performed the create.  If the file already existed, no inode is
returned in the reply.  This allows ceph to set the created flag
in atomic_open so that permissions are properly checked in the case
that the file wasn't created by the create call to the mds.

To ensure compability with previous kernels, a feature for sending
back the inode in the create reply was added, so that the mds will
only send back the inode if the client indicates it supports the
feature.

Signed-off-by: Sam Lang <sam.lang@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:36 -06:00
Sam Lang
79aec9844d ceph: Check for err on mds request in atomic_open
The error returned by ceph_mdsc_do_request includes errors sending the
request, errors on timeout, or any errors coming from the mds.  If
ceph_mdsc_do_request returns an error, the reply struct will most likely
be bogus.  We need to bail out and propogate the error instead of
overwriting it.

Signed-off-by: Sam Lang <sam.lang@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-01-17 12:42:36 -06:00
Sage Weil
0fa6ebc600 libceph: fix protocol feature mismatch failure path
We should not set con->state to CLOSED here; that happens in
ceph_fault() in the caller, where it first asserts that the state
is not yet CLOSED.  Avoids a BUG when the features don't match.

Since the fail_protocol() has become a trivial wrapper, replace
calls to it with direct calls to reset_connection().

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-27 20:27:04 -06:00
Alex Elder
122070a2ff libceph: WARN, don't BUG on unexpected connection states
A number of assertions in the ceph messenger are implemented with
BUG_ON(), killing the system if connection's state doesn't match
what's expected.  At this point our state model is (evidently) not
well understood enough for these assertions to trigger a BUG().
Convert all BUG_ON(con->state...) calls to be WARN_ON(con->state...)
so we learn about these issues without killing the machine.

We now recognize that a connection fault can occur due to a socket
closure at any time, regardless of the state of the connection.  So
there is really nothing we can assert about the state of the
connection at that point so eliminate that assertion.

Reported-by: Ugis <ugis22@gmail.com>
Tested-by: Ugis <ugis22@gmail.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-27 20:27:04 -06:00
Alex Elder
e6d50f67a6 libceph: always reset osds when kicking
When ceph_osdc_handle_map() is called to process a new osd map,
kick_requests() is called to ensure all affected requests are
updated if necessary to reflect changes in the osd map.  This
happens in two cases:  whenever an incremental map update is
processed; and when a full map update (or the last one if there is
more than one) gets processed.

In the former case, the kick_requests() call is followed immediately
by a call to reset_changed_osds() to ensure any connections to osds
affected by the map change are reset.  But for full map updates
this isn't done.

Both cases should be doing this osd reset.

Rather than duplicating the reset_changed_osds() call, move it into
the end of kick_requests().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-27 20:27:04 -06:00
Alex Elder
ab60b16d3c libceph: move linger requests sooner in kick_requests()
The kick_requests() function is called by ceph_osdc_handle_map()
when an osd map change has been indicated.  Its purpose is to
re-queue any request whose target osd is different from what it
was when it was originally sent.

It is structured as two loops, one for incomplete but registered
requests, and a second for handling completed linger requests.
As a special case, in the first loop if a request marked to linger
has not yet completed, it is moved from the request list to the
linger list.  This is as a quick and dirty way to have the second
loop handle sending the request along with all the other linger
requests.

Because of the way it's done now, however, this quick and dirty
solution can result in these incomplete linger requests never
getting re-sent as desired.  The problem lies in the fact that
the second loop only arranges for a linger request to be sent
if it appears its target osd has changed.  This is the proper
handling for *completed* linger requests (it avoids issuing
the same linger request twice to the same osd).

But although the linger requests added to the list in the first loop
may have been sent, they have not yet completed, so they need to be
re-sent regardless of whether their target osd has changed.

The first required fix is we need to avoid calling __map_request()
on any incomplete linger request.  Otherwise the subsequent
__map_request() call in the second loop will find the target osd
has not changed and will therefore not re-send the request.

Second, we need to be sure that a sent but incomplete linger request
gets re-sent.  If the target osd is the same with the new osd map as
it was when the request was originally sent, this won't happen.
This can be fixed through careful handling when we move these
requests from the request list to the linger list, by unregistering
the request *before* it is registered as a linger request.  This
works because a side-effect of unregistering the request is to make
the request's r_osd pointer be NULL, and *that* will ensure the
second loop actually re-sends the linger request.

Processing of such a request is done at that point, so continue with
the next one once it's been moved.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-27 20:27:04 -06:00
Alex Elder
c3e946ce72 rbd: get rid of rbd_{get,put}_dev()
The functions rbd_get_dev() and rbd_put_dev() are trivial wrappers
that add no value, and their existence suggests they may do more
than what they do.

Get rid of them.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
2012-12-20 10:56:44 -06:00
Alex Elder
c89ce05e0c libceph: register request before unregister linger
In kick_requests(), we need to register the request before we
unregister the linger request.  Otherwise the unregister will
reset the request's osd pointer to NULL.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20 10:56:39 -06:00
Alex Elder
a978fa20fb libceph: don't use rb_init_node() in ceph_osdc_alloc_request()
The red-black node in the ceph osd request structure is initialized
in ceph_osdc_alloc_request() using rbd_init_node().  We do need to
initialize this, because in __unregister_request() we call
RB_EMPTY_NODE(), which expects the node it's checking to have
been initialized.  But rb_init_node() is apparently overkill, and
may in fact be on its way out.  So use RB_CLEAR_NODE() instead.

For a little more background, see this commit:
    4c199a93 rbtree: empty nodes have no color"

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20 10:56:33 -06:00
Alex Elder
3ee5234df6 libceph: init event->node in ceph_osdc_create_event()
The red-black node node in the ceph osd event structure is not
initialized in create_osdc_create_event().  Because this node can
be the subject of a RB_EMPTY_NODE() call later on, we should ensure
the node is initialized properly for that.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20 10:56:28 -06:00
Alex Elder
f407731d12 libceph: init osd->o_node in create_osd()
The red-black node node in the ceph osd structure is not initialized
in create_osd().  Because this node can be the subject of a
RB_EMPTY_NODE() call later on, we should ensure the node is
initialized properly for that.  Add a call to RB_CLEAR_NODE()
initialize it.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20 10:56:21 -06:00
Alex Elder
28362986f8 libceph: report connection fault with warning
When a connection's socket disconnects, or if there's a protocol
error of some kind on the connection, a fault is signaled and
the connection is reset (closed and reopened, basically).  We
currently get an error message on the log whenever this occurs.

A ceph connection will attempt to reestablish a socket connection
repeatedly if a fault occurs.  This means that these error messages
will get repeatedly added to the log, which is undesirable.

Change the error message to be a warning, so they don't get
logged by default.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-20 10:56:13 -06:00
Alex Elder
7bb21d68c5 libceph: socket can close in any connection state
A connection's socket can close for any reason, independent of the
state of the connection (and without irrespective of the connection
mutex).  As a result, the connectino can be in pretty much any state
at the time its socket is closed.

Handle those other cases at the top of con_work().  Pull this whole
block of code into a separate function to reduce the clutter.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 12:07:32 -06:00
Alex Elder
b8f5c6edca rbd: don't use ENOTSUPP
ENOTSUPP is not a standard errno (it shows up as "Unknown error 524"
in an error message).  This is what was getting produced when the
the local rbd code does not implement features required by a
discovered rbd image.

Change the error code returned in this case to ENXIO.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 12:07:32 -06:00
Alex Elder
61c7403562 rbd: remove linger unconditionally
In __unregister_linger_request(), the request is being removed
from the osd client's req_linger list only when the request
has a non-null osd pointer.  It should be done whether or not
the request currently has an osd.

This is most likely a non-issue because I believe the request
will always have an osd when this function is called.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 12:07:31 -06:00
Alex Elder
2fd82b9e92 rbd: get rid of RBD_MAX_SEG_NAME_LEN
RBD_MAX_SEG_NAME_LEN represents the maximum length of an rbd object
name (i.e., one of the objects providing storage backing an rbd
image).

Another symbol, MAX_OBJ_NAME_SIZE, is used in the osd client code to
define the maximum length of any object name in an osd request.

Right now they disagree, with RBD_MAX_SEG_NAME_LEN being too big.

There's no real benefit at this point to defining the rbd object
name length limit separate from any other object name, so just
get rid of RBD_MAX_SEG_NAME_LEN and use MAX_OBJ_NAME_SIZE in its
place.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 08:37:29 -06:00
Alex Elder
685a7555ca libceph: avoid using freed osd in __kick_osd_requests()
If an osd has no requests and no linger requests, __reset_osd()
will just remove it with a call to __remove_osd().  That drops
a reference to the osd, and therefore the osd may have been free
by the time __reset_osd() returns.  That function offers no
indication this may have occurred, and as a result the osd will
continue to be used even when it's no longer valid.

Change__reset_osd() so it returns an error (ENODEV) when it
deletes the osd being reset.  And change __kick_osd_requests() so it
returns immediately (before referencing osd again) if __reset_osd()
returns *any* error.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 08:37:23 -06:00
Alex Elder
7d5f24812b ceph: don't reference req after put
In __unregister_request(), there is a call to list_del_init()
referencing a request that was the subject of a call to
ceph_osdc_put_request() on the previous line.  This is not
safe, because the request structure could have been freed
by the time we reach the list_del_init().

Fix this by reversing the order of these lines.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>
2012-12-17 08:37:19 -06:00
Alex Elder
42382b709b rbd: do not allow remove of mounted-on image
There is no check in rbd_remove() to see if anybody holds open the
image being removed.  That's not cool.

Add a simple open count that goes up and down with opens and closes
(releases) of the device, and don't allow an rbd image to be removed
if the count is non-zero.

Protect the updates of the open count value with ctl_mutex to ensure
the underlying rbd device doesn't get removed while concurrently
being opened.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2012-12-17 08:36:59 -06:00
David Zafman
8884d53dd6 libceph: Unlock unprocessed pages in start_read() error path
Function start_read() can get an error before processing all pages.
It must not only release the remaining pages, but unlock them too.

This fixes http://tracker.newdream.net/issues/3370

Signed-off-by: David Zafman <david.zafman@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:09 -06:00
Yan, Zheng
0e5e1774a9 ceph: call handle_cap_grant() for cap import message
If client sends cap message that requests new max size during
exporting caps, the exporting MDS will drop the message quietly.
So the client may wait for the reply that updates the max size
forever. call handle_cap_grant() for cap import message can
avoid this issue.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng
a85f50b6ef ceph: Fix __ceph_do_pending_vmtruncate
we should set i_truncate_pending to 0 after page cache is truncated
to i_truncate_size

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng
0685235ffd ceph: Don't add dirty inode to dirty list if caps is in migration
Add dirty inode to cap_dirty_migrating list instead, this can avoid
ceph_flush_dirty_caps() entering infinite loop.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:08 -06:00
Yan, Zheng
ed75ec2cd1 ceph: Fix infinite loop in __wake_requests
__wake_requests() will enter infinite loop if we use it to wake
requests in the session->s_waiting list. __wake_requests() deletes
requests from the list and __do_request() adds requests back to
the list.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:07 -06:00
Yan, Zheng
5e62ad3015 ceph: Don't update i_max_size when handling non-auth cap
The cap from non-auth mds doesn't have a meaningful max_size value.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-12-13 08:13:07 -06:00
Joe Perches
d2cc4dde92 bdi_register: add __printf verification, fix arg mismatch
__printf is useful to verify format and arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:07 -06:00
Sage Weil
83aff95eb9 libceph: remove 'osdtimeout' option
This would reset a connection with any OSD that had an outstanding
request that was taking more than N seconds.  The idea was that if the
OSD was buggy, the client could compensate by resending the request.

In reality, this only served to hide server bugs, and we haven't
actually seen such a bug in quite a while.  Moreover, the userspace
client code never did this.

More importantly, often the request is taking a long time because the
OSD is trying to recover, or overloaded, and killing the connection
and retrying would only make the situation worse by giving the OSD
more work to do.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:06 -06:00
Cyril Roelandt
cfc84c9f73 ceph: fix dentry reference leak in ceph_encode_fh().
dput() was not called in the error path.

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-12-13 08:13:06 -06:00
Sage Weil
22cddde104 ceph: Fix i_size update race
ceph_aio_write() has an optimization that marks cap EPH_CAP_FILE_WR
dirty before data is copied to page cache and inode size is updated.
If ceph_check_caps() flushes the dirty cap before the inode size is
updated, MDS can miss the new inode size. The fix is move
ceph_{get,put}_cap_refs() into ceph_write_{begin,end}() and call
__ceph_mark_dirty_caps() after inode size is updated.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-11-05 11:07:23 -08:00
Yan, Zheng
4d1d0534f5 ceph: Hold caps_list_lock when adjusting caps_{use, total}_count
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
2012-11-04 03:08:24 -08:00
Alex Elder
9e15b77d9a rbd: get additional info in parent spec
When a layered rbd image has a parent, that parent is identified
only by its pool id, image id, and snapshot id.  Images that have
been mapped also record *names* for those three id's.

Add code to look up these names for parent images so they match
mapped images more closely.  Skip doing this for an image if it
already has its pool name defined (this will be the case for images
mapped by the user).

It is possible that an the name of a parent image can't be
determined, even if the image id is valid.  If this occurs it
does not preclude correct operation, so don't treat this as
an error.

On the other hand, defined pools will always have both an id and a
name.   And any snapshot of an image identified as a parent for a
clone image will exist, and will have a name (if not it indicates
some other internal error).  So treat failure to get these bits
of information as errors.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder
72afc71ffc libceph: define ceph_pg_pool_name_by_id()
Define and export function ceph_pg_pool_name_by_id() to supply
the name of a pg pool whose id is given.  This will be used by
the next patch.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder
86b00e0da6 rbd: get parent spec for version 2 images
Add support for getting the the information identifying the parent
image for rbd images that have them.  The child image holds a
reference to its parent image specification structure.  Create a new
entry "parent" in /sys/bus/rbd/image/N/ to report the identifying
information for the parent image, if any.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder
a92ffdf8a9 rbd: allow null image name
Format 2 parent images are partially identified by their image id,
but it may not be possible to determine their image name.  The name
is not strictly needed for correct operation, so we won't be
treating it as an error if we don't know it.  Handle this case
gracefully in rbd_name_show().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00
Alex Elder
2c0d0a10ea rbd: allow null image name
We will know the image id for format 2 parent images, but won't
initially know its image name.  Avoid making the query for an image
id in rbd_dev_image_id() if it's already known.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-11-01 07:55:42 -05:00