Somehow, I missed this little item in Documentation/atomic_ops.txt:
*** WARNING: atomic_read() and atomic_set() DO NOT IMPLY BARRIERS! ***
Create and use some helper functions that include the proper memory
barriers for manipulating the done field.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This commit:
bc7a62ee5 rbd: prevent open for image being removed
added checking for removing rbd before allowing an open, and used
the same request spinlock for protecting that and updating the open
count as is used for the request queue.
However it used the non-irq protected version of the spinlocks.
Fix that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is a check in the completion path for osd requests that
ensures the number of pages allocated is enough to hold the amount
of incoming data expected.
For bio requests coming from rbd the "number of pages" is not really
meaningful (although total length would be). So stop requiring that
nr_pages be supplied for bio requests. This is done by checking
whether the pages pointer is null before checking the value of
nr_pages.
Note that this value is passed on to the messenger, but there it's
only used for debugging--it's never used for validation.
While here, change another spot that used r_pages in a debug message
inappropriately, and also invalidate the r_con_filling_msg pointer
after dropping a reference to it.
This resolves:
http://tracker.ceph.com/issues/3875
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Currently, if the OSD client finds an osd request has had a bio list
attached to it, it drops a reference to it (or rather, to the first
entry on that list) when the request is released.
The code that added that reference (i.e., the rbd client) is
therefore required to take an extra reference to that first bio
structure.
The osd client doesn't really do anything with the bio pointer other
than transfer it from the osd request structure to outgoing (for
writes) and ingoing (for reads) messages. So it really isn't the
right place to be taking or dropping references.
Furthermore, the rbd client already holds references to all bio
structures it passes to the osd client, and holds them until the
request is completed. So there's no need for this extra reference
whatsoever.
So remove the bio_put() call in ceph_osdc_release_request(), as
well as its matching bio_get() call in rbd_osd_req_create().
This change could lead to a crash if old libceph.ko was used with
new rbd.ko. Add a compatibility check at rbd initialization time to
avoid this possibilty.
This resolves:
http://tracker.ceph.com/issues/3798 and
http://tracker.ceph.com/issues/3799
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An open request for a mapped rbd image can arrive while removal of
that mapping is underway. We need to prevent such an open request
from succeeding. (It appears that Maciej Galkiewicz ran into this
problem.)
Define and use a "removing" flag to indicate a mapping is getting
removed. Set it in the remove path after verifying nothing holds
the device open. And check it in the open path before allowing the
open to proceed. Acquire the rbd device's lock around each of these
spots to avoid any races accessing the flags and open_count fields.
This addresses:
http://tracker.newdream.net/issues/3427
Reported-by: Maciej Galkiewicz <maciejgalkiewicz@ragnarson.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a new rbd device flags field, manipulated using bit
operations. Replace the use of the current "exists" flag with a bit
in this new "flags" field. Add a little commentary about the
"exists" flag, which does not need to be manipulated atomically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When we register an osd request to linger, it means that request
will stay around (under control of the osd client) until we've
unregistered it. We do that for an rbd image's header object, and
we keep a pointer to the object request associated with it.
Keep a reference to the watch object request for as long as it is
registered to linger. Drop it again after we've removed the linger
registration.
This resolves:
http://tracker.ceph.com/issues/3937
(Note: this originally came about because the osd client was
issuing a callback more than once. But that behavior will be
changing soon, documented in tracker issue 3967.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Switch to keeping track of the object request pointer rather than
the osd request used to watch the rbd image header object.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Move the code that unregisters an rbd device's lingering header
object watch request into rbd_dev_header_watch_sync(), so it
occurs in the same function that originally sets up that request.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Get rid rbd_req_sync_exec() because it is no longer used. That
eliminates the last use of rbd_req_sync_op(), so get rid of that
too. And finally, that leaves rbd_do_request() unreferenced, so get
rid of that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reimplement synchronous object method calls using the new request
tracking code. Use the name rbd_obj_method_sync()
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When we receive notification of a change to an rbd image's header
object we need to refresh our information about the image (its
size and snapshot context). Once we have refreshed our rbd image
we need to acknowledge the notification.
This acknowledgement was previously done synchronously, but there's
really no need to wait for it to complete.
Change it so the caller doesn't wait for the notify acknowledgement
request to complete. And change the name to reflect it's no longer
synchronous.
This resolves:
http://tracker.newdream.net/issues/3877
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Get rid rbd_req_sync_notify_ack() because it is no longer used.
As a result rbd_simple_req_cb() becomes unreferenced, so get rid
of that too.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Use the new object request tracking mechanism for handling a
notify_ack request.
Move the callback function below the definition of this so we don't
have to do a pre-declaration.
This resolves:
http://tracker.newdream.net/issues/3754
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Implement a new function to set up or tear down a watch event
for an mapped rbd image header using the new request code.
Create a new object request type "nodata" to handle this. And
define rbd_osd_trivial_callback() which simply marks a request done.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Delete rbd_req_sync_read() is no longer used, so get rid of it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reimplement the synchronous read operation used for reading a
version 1 header using the new request tracking code. Name the
resulting function rbd_obj_read_sync() to better reflect that
it's a full object operation, not an object request. To do this,
implement a new OBJ_REQUEST_PAGES object request type.
This implements a new mechanism to allow the caller to wait for
completion for an rbd_obj_request by calling rbd_obj_request_wait().
This partially resolves:
http://tracker.newdream.net/issues/3755
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The two remaining callers of rbd_do_request() always pass a null
collection pointer, so the "coll" and "coll_index" parameters are
not needed. There is no other use of that data structure, so it
can be eliminated.
Deleting them means there is no need to allocate a rbd_request
structure for the callback function. And since that's the only use
of *that* structure, it too can be eliminated.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Now that the request function has been replaced by one using the new
request management data structures the old one can go away.
Deleting it makes rbd_dev_do_request() no longer needed, and
deleting that makes other functions unneeded, and so on.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch fully implements the new request tracking code for rbd
I/O requests.
Each I/O request to an rbd image will get an rbd_image_request
structure allocated to track it. This provides access to all
information about the original request, as well as access to the
set of one or more object requests that are initiated as a result
of the image request.
An rbd_obj_request structure defines a request sent to a single osd
object (possibly) as part of an rbd image request. An rbd object
request refers to a ceph_osd_request structure built up to represent
the request; for now it will contain a single osd operation. It
also provides space to hold the result status and the version of the
object when the osd request completes.
An rbd_obj_request structure can also stand on its own. This will
be used for reading the version 1 header object, for issuing
acknowledgements to event notifications, and for making object
method calls.
All rbd object requests now complete asynchronously with respect
to the osd client--they supply a common callback routine.
This resolves:
http://tracker.newdream.net/issues/3741
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
When an rbd image is initially mapped a watch event is registered so
we can do something if the header object changes.
The code that does this currently loops if initiating the watch
request results in an ERANGE error. The osds will never return
ERANGE, so there's no reason to do this loop, so get rid of it.
This resolves:
http://tracker.newdream.net/issues/3860
Note that the problem this loop was intended to solve is a race
between collecting image header information and setting up the watch
on the header object. The real fix for that problem is described
here:
http://tracker.newdream.net/issues/3871
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The return type of rbd_get_num_segments() is int, but the values it
operates on are u64. Although it's not likely, there's no guarantee
the result won't exceed what can be respresented in an int. The
function is already designed to return -ERANGE on error, so just add
this possible overflow as another reason to return that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
A few very minor changes to the rbd code:
- RBD_MAX_OPT_LEN is unused, so get rid of it
- Consolidate rbd options definitions
- Make rbd_segment_name() return pointer to const char
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Dan Mick <dan.mick@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Alex Elder