Commit Graph

48 Commits

Author SHA1 Message Date
Markus Armbruster 84d18f065f Use error_is_set() only when necessary
error_is_set(&var) is the same as var != NULL, but it takes
whole-program analysis to figure that out.  Unnecessarily hard for
optimizers, static checkers, and human readers.  Dumb it down to
obvious.

Gets rid of several dozen Coverity false positives.

Note that the obvious form is already used in many places.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-02-17 11:57:23 -05:00
Stefan Hajnoczi e04fb07fd1 rbd: switch from pipe to QEMUBH completion notification
rbd callbacks are called from non-QEMU threads.  Up until now a pipe was
used to signal completion back to the QEMU iothread.

The pipe writer code handles EAGAIN using select(2).  The select(2) API
is not scalable since fd_set size is static.  FD_SET() can write beyond
the end of fd_set if the file descriptor number is too high.  (QEMU's
main loop uses poll(2) to avoid this issue with select(2).)

Since the pipe itself is quite clumsy to use and QEMUBH is now
thread-safe, just schedule a BH from the rbd callback function.  This
way we can simplify I/O completion in addition to eliminating the
potential FD_SET() crash when file descriptor numbers become too high.

Crash scenario: QEMU already has 1024 file descriptors open.  Hotplug an
rbd drive and get the pipe writer to take the select(2) code path.

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Tested-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-01-22 12:07:16 +01:00
Peter Crosthwaite 87ea75d5e1 qemu-option: Remove qemu_opts_create_nofail
This is a boiler-plate _nofail variant of qemu_opts_create. Remove and
use error_abort in call sites.

null/0 arguments needs to be added for the id and fail_if_exists fields
in affected callsites due to argument inconsistency between the normal and
no_fail variants.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-06 15:02:30 -05:00
Stefan Hajnoczi 9e6337d081 rbd: avoid qemu_rbd_snap_list() memory leaks
When there are no snapshots qemu_rbd_snap_list() returns 0 and the
snapshot table pointer is NULL.  Don't forget to free the snaps buffer
we allocated for librbd rbd_snap_list().

When the function succeeds don't forget to free the snaps buffer after
calling rbd_snap_list_end().

Cc: qemu-stable@nongnu.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 16:22:00 +02:00
Benoît Canet 030be32184 block: introduce BlockDriver.bdrv_needs_filename to enable some drivers.
Some drivers will have driver specifics options but no filename.
This new bool allow the block layer to treat them correctly.

The .bdrv_needs_filename is set in drivers not having .bdrv_parse_filename and
not having .bdrv_open.

The first exception to this rule will be the quorum driver.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-25 16:21:28 +02:00
Max Reitz d5124c00d8 bdrv: Use "Error" for creating images
Add an Error ** parameter to BlockDriver.bdrv_create to allow more
specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:48 +02:00
Max Reitz 015a1036a7 bdrv: Use "Error" for opening images
Add an Error ** parameter to BlockDriver.bdrv_open and
BlockDriver.bdrv_file_open to allow more specific error messages.

Signed-off-by: Max Reitz <mreitz@redhat.com>
2013-09-12 10:12:47 +02:00
Wenchao Xia a89d89d3e6 snapshot: distinguish id and name in snapshot delete
Snapshot creation actually already distinguish id and name since it take
a structured parameter *sn, but delete can't. Later an accurate delete
is needed in qmp_transaction abort and blockdev-snapshot-delete-sync,
so change its prototype. Also *errp is added to tip error, but return
value is kepted to let caller check what kind of error happens. Existing
caller for it are savevm, delvm and qemu-img, they are not impacted by
introducing a new function bdrv_snapshot_delete_by_id_or_name(), which
check the return value and do the operation again.

Before this patch:
  For qcow2, it search id first then name to find the one to delete.
  For rbd, it search name.
  For sheepdog, it does nothing.

After this patch:
  For qcow2, logic is the same by call it twice in caller.
  For rbd, it always fails in delete with id, but still search for name
in second try, no change to user.

Some code for *errp is based on Pavel's patch.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-09-12 10:12:47 +02:00
Stefan Hajnoczi f2e5dca46b aio: drop io_flush argument
The .io_flush() handler no longer exists and has no users.  Drop the
io_flush argument to aio_set_fd_handler() and related functions.

The AioFlushEventNotifierHandler and AioFlushHandler typedefs are no
longer used and are dropped too.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19 15:52:19 +02:00
Stefan Hajnoczi 5d289cc724 block/rbd: drop qemu_rbd_aio_flush_cb()
.io_flush() is no longer called so drop qemu_rbd_aio_flush_cb().
qemu_aio_count is unused now so drop it too.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-19 15:52:19 +02:00
Peter Lieven 3ac216270a block: change default of .has_zero_init to 0
.has_zero_init defaults to 1 for all formats and protocols.

this is a dangerous default since this means that all
new added drivers need to manually overwrite it to 0 if
they do not ensure that a device is zero initialized
after bdrv_create().

if a driver needs to explicitly set this value to
1 its easier to verify the correctness in the review process.

during review of the existing drivers it turned out
that ssh and gluster had a wrong default of 1.
both protocols support host_devices as backend
which are not by default zero initialized. this
wrong assumption will lead to possible corruption
if qemu-img convert is used to write to such a backend.

vpc and vmdk also defaulted to 1 altough they support
fixed respectively flat extends. this has to be addresses
in separate patches. both formats as well as the mentioned
ssh and gluster are turned to the default of 0 with this
patch for safety.

a similar problem with the wrong default existed for
iscsi most likely because the driver developer did
oversee the default value of 1.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28 13:52:35 +02:00
Kevin Wolf c3ca988d2b rbd: Fix use after free in rbd_open()
Commit a9ccedc3 frees the QemuOpts for the driver-specific options
immediately, even though it still needs the filename string that is
contained there. This doesn't work. Move the deletion of the QemuOpts to
the end of the function where its content isn't needed any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-26 13:26:28 +02:00
Kevin Wolf 56d1b4d21d block: Remove filename parameter from .bdrv_file_open()
It is unused now in all block drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22 11:34:35 +02:00
Kevin Wolf a9ccedc3da rbd: Use bdrv_open options instead of filename
This is only to convert the internal interface that is used for passing
the "filename" to be parsed, but converting to actual fine grained
options is left for another day, as it doesn't look trivial.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2013-04-22 10:27:59 +02:00
Josh Durgin dc7588c1eb rbd: add an asynchronous flush
The existing bdrv_co_flush_to_disk implementation uses rbd_flush(),
which is sychronous and causes the main qemu thread to block until it
is complete. This results in unresponsiveness and extra latency for
the guest.

Fix this by using an asynchronous version of flush.  This was added to
librbd with a special #define to indicate its presence, since it will
be backported to stable versions. Thus, there is no need to check the
version of librbd.

Implement this as bdrv_aio_flush, since it matches other aio functions
in the rbd block driver, and leave out bdrv_co_flush_to_disk when the
asynchronous version is available.

Reported-by: Oliver Francke <oliver@filoo.de>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-04-15 10:18:05 +02:00
Liu Yuan d43731c758 rbd: fix compile error
Commit 787e4a85 [block: Add options QDict to bdrv_file_open() prototypes] didn't
update rbd.c accordingly.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-03-25 09:51:43 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Paolo Bonzini 737e150e89 block: move include files to include/block/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:31 +01:00
Stefan Priebe 473c7f0255 rbd: Fix race between aio completition and aio cancel
This one fixes a race which qemu had also in iscsi block driver
between cancellation and io completition.

qemu_rbd_aio_cancel was not synchronously waiting for the end of
the command.

To archieve this it introduces a new status flag which uses
-EINPROGRESS.

Signed-off-by: Stefan Priebe <s.priebe@profihost.ag>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-12-11 11:05:11 +01:00
Stefan Priebe 08448d5195 use int64_t for return values from rbd instead of int
rbd / rados tends to return pretty often length of writes
or discarded blocks. These values might be bigger than int.

The steps to reproduce are:

  mkfs.xfs -f a whole device bigger than int in bytes. mkfs.xfs sends
  a discard. Important is that you use scsi-hd and set
  discard_granularity=512. Otherwise rbd disabled discard support.

Signed-off-by: Stefan Priebe <s.priebe@profihost.ag>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-21 09:43:23 +01:00
Stefan Hajnoczi d7331bed11 aio: rename AIOPool to AIOCBInfo
Now that AIOPool no longer keeps a freelist, it isn't really a "pool"
anymore.  Rename it to AIOCBInfo and make it const since it no longer
needs to be modified.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-11-14 18:19:21 +01:00
Jeff Cody 39c9fb9565 block: do not parse BDRV_O_CACHE_WB in block drivers
Block drivers should ignore BDRV_O_CACHE_WB in .bdrv_open flags,
and in the bs->open_flags.

This patch removes the code, leaving the behaviour behind as if
BDRV_O_CACHE_WB was set.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-09-24 15:15:11 +02:00
Anthony Liguori 23797df3d9 Merge remote-tracking branch 'mjt/mjt-iov2' into staging
* mjt/mjt-iov2:
  rewrite iov_send_recv() and move it to iov.c
  cleanup qemu_co_sendv(), qemu_co_recvv() and friends
  export iov_send_recv() and use it in iov_send() and iov_recv()
  rename qemu_sendv to iov_send, change proto and move declarations to iov.h
  change qemu_iovec_to_buf() to match other to,from_buf functions
  consolidate qemu_iovec_copy() and qemu_iovec_concat() and make them consistent
  allow qemu_iovec_from_buffer() to specify offset from which to start copying
  consolidate qemu_iovec_memset{,_skip}() into single function and use existing iov_memset()
  rewrite iov_* functions
  change iov_* function prototypes to be more appropriate
  virtio-serial-bus: use correct lengths in control_out() message

Conflicts:
	tests/Makefile

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-07-09 12:35:06 -05:00
Josh Durgin b11f38fcdf rbd: hook up cache options
Writeback caching was added in Ceph 0.46, and writethrough will be in
0.47. These are controlled by general config options, so there's no
need to check for librbd version.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-06-15 14:03:42 +02:00
Michael Tokarev d5e6b1619c change qemu_iovec_to_buf() to match other to,from_buf functions
It now allows specifying offset within qiov to start from and
amount of bytes to copy.  Actual implementation is just a call
to iov_to_buf().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Michael Tokarev 03396148bc allow qemu_iovec_from_buffer() to specify offset from which to start copying
Similar to
 qemu_iovec_memset(QEMUIOVector *qiov, size_t offset,
                   int c, size_t bytes);
the new prototype is:
 qemu_iovec_from_buf(QEMUIOVector *qiov, size_t offset,
                     const void *buf, size_t bytes);

The processing starts at offset bytes within qiov.

This way, we may copy a bounce buffer directly to
a middle of qiov.

This is exactly the same function as iov_from_buf() from
iov.c, so use the existing implementation and rename it
to qemu_iovec_from_buf() to be shorter and to match the
utility function.

As with utility implementation, we now assert that the
offset is inside actual iovec.  Nothing changed for
current callers, because `offset' parameter is new.

While at it, stop using "bounce-qiov" in block/qcow2.c
and copy decrypted data directly from cluster_data
instead of recreating a temp qiov for doing that.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2012-06-11 23:12:11 +04:00
Josh Durgin 787f31330e rbd: add discard support
Change the write flag to an operation type in RBDAIOCB, and make the
buffer optional since discard doesn't use it.

Discard is first included in librbd 0.1.2 (which is in Ceph 0.46).
If librbd is too old, leave out qemu_rbd_aio_discard entirely,
so the old behavior is preserved.

Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-02 18:41:42 +02:00
Paolo Bonzini bafbd6a1c6 aio: remove process_queue callback and qemu_aio_process_queue
Both unused after the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-19 16:37:53 +02:00
Gregory Farnum bd60324706 rbd: wire up snapshot removal and rollback functionality
Signed-off-by: Greg Farnum <gregory.farnum@dreamhost.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-01-26 11:39:03 +01:00
Paolo Bonzini 6b620ca3b0 prepare for future GPLv2+ relicensing
All files under GPLv2 will get GPLv2+ changes starting tomorrow.
event_notifier.c and exec-obsolete.h were only ever touched by Red Hat
employees and can be relicensed now.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-01-13 10:55:56 -06:00
Josh Durgin b9c532903f rbd: always set out parameter in qemu_rbd_snap_list
The caller expects psn_tab to be NULL when there are no snapshots or
an error occurs. This results in calling g_free on an invalid address.

Reported-by: Oliver Francke <Oliver@filoo.de>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:08 +01:00
Paolo Bonzini 91977c2e5f block: qemu_aio_get does not return NULL
Initially done with the following semantic patch:

@ rule1 @
expression E;
statement S;
@@
  E = qemu_aio_get (...);
(
- if (E == NULL) { ... }
|
- if (E)
    { <... S ...> }
)

which however missed occurrences in linux-aio.c and posix-aio-compat.c.
Those were done by hand.

The change in vdi_aio_setup's caller was also done by hand.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:08 +01:00
Kevin Wolf c68b89acd6 block: Rename bdrv_co_flush to bdrv_co_flush_to_disk
There are two different types of flush that you can do: Flushing one level up
to the OS (i.e. writing data to the host page cache) or flushing it all the way
down to the disk. The existing functions flush to the disk, reflect this in the
function name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-11-11 14:02:59 +01:00
Paolo Bonzini 8b94ff8573 block: change flush to co_flush
Since coroutine operation is now mandatory, convert all bdrv_flush
implementations to coroutines.  For qcow2, this means taking the lock.
Other implementations are simpler and just forward bdrv_flush to the
underlying protocol, so they can avoid the lock.

The bdrv_flush callback is then unused and can be eliminated.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-21 17:34:14 +02:00
Sage Weil 16a06b2430 rbd: allow escaping in config string
The config string is variously delimited by =, @, and /, depending on the
field.  Allow these characters to be escaped by preceeding them with \.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-20 14:34:17 +02:00
Sage Weil 7a3f5fe9af rbd: call flush, if available
librbd recently added async writeback and flush support.  If the new
rbd_flush() call is available, call it.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-20 12:27:44 +02:00
Sage Weil 9e1fbcde57 rbd: update comment heading
Properly document the configuration string syntax and semantics.  Remove
(out of date) details about the librbd implementation.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-20 12:27:44 +02:00
Sage Weil f9fe18ec77 rbd: ignore failures when reading from default conf location
If we are reading from the default config location, ignore any failures.
It is perfectly legal for the user to specify exactly the options they need
and to not rely on any config file.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-20 12:27:44 +02:00
Sage Weil eb93d5d990 rbd: fix leak in qemu_rbd_open failure paths
Fix leak of s->snap in failure path.  Simplify error paths for the whole
function.

Reported-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:21 +02:00
Sage Weil dfe80b071b rbd: clean up, fix style
No assignment in condition.  Remove duplicate ret > 0 check.

Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:21 +02:00
Sage Weil 7c7e9df023 rbd: allow client id to be specified in config string
Allow the client id to be specified in the config string via 'id=' so that
users can control who they authenticate as.  Currently they are stuck with
the default ('admin').  This is necessary for anyone using authentication
in their environment.

Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-09-12 15:17:20 +02:00
Anthony Liguori 7267c0947d Use glib memory allocation and free functions
qemu_malloc/qemu_free no longer exist after this commit.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-08-20 23:01:08 -05:00
Stefan Weil 7bf4162a80 block/rbd: Remove unused local variable
Variable 'snap' is assigned a value that is never used.
Remove snap and the related code.

Cc: Christian Brunner <chb@muc.de>
Cc: Josh Durgin <josh.durgin@dreamhost.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Reviewed-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-14 10:01:19 +02:00
Josh Durgin 30cdc48cc8 rbd: Add bdrv_truncate implementation
Reviewed-by: Christian Brunner <chb@muc.de>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 11:56:40 +02:00
Josh Durgin 51a135287a rbd: check return values when scheduling aio
If scheduling fails, the number of outstanding I/Os must be correct,
or there will be a hang when waiting for everything to be flushed.

Reviewed-by: Christian Brunner <chb@muc.de>
Reported-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 11:56:40 +02:00
Josh Durgin fab5cf592c rbd: allow configuration of rados from the rbd filename
The new format is rbd:pool/image[@snapshot][:option1=value1[:option2=value2...]]
Each option is used to configure rados, and may be any Ceph option, or "conf".
The "conf" option specifies a Ceph configuration file to read.

This allows rbd volumes from more than one Ceph cluster to be used by
specifying different monitor addresses, as well as having different
logging levels or locations for different volumes.

Reviewed-by: Christian Brunner <chb@muc.de>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 11:56:40 +02:00
Josh Durgin ad32e9c003 rbd: use the higher level librbd instead of just librados
librbd stacks on top of librados to provide access
to rbd images.

Using librbd simplifies the qemu code, and allows
qemu to use new versions of the rbd format
with few (if any) changes.

Reviewed-by: Christian Brunner <chb@muc.de>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-06-08 11:56:39 +02:00
Christian Brunner f27aaf4b53 ceph/rbd block driver for qemu-kvm
RBD is an block driver for the distributed file system Ceph
(http://ceph.newdream.net/). This driver uses librados (which is part
of the Ceph server) for direct access to the Ceph object store and is
running entirely in userspace (Yehuda also wrote a driver for the
linux kernel, that can be used to access rbd volumes as a block
device).

Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Christian Brunner <chb@muc.de>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-14 15:44:21 +01:00