Commit Graph

96 Commits

Author SHA1 Message Date
Alex Elder ed63f4fd9a rbd: drop rbd_header_from_disk() gfp_flags parameter
The function rbd_header_from_disk() is only called in one spot, and
it passes GFP_KERNEL as its value for the gfp_flags parameter.

Just drop that parameter and substitute GFP_KERNEL everywhere within
that function it had been used.  (If we find we need the parameter
again in the future it's easy enough to add back again.)

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:50 -07:00
Alex Elder 9a5d690b08 rbd: snapc is unused in rbd_req_sync_read()
The "snapc" parameter to in rbd_req_sync_read() is not used, so
get rid of it.

Reported-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:49 -07:00
Alex Elder de71a2970d rbd: rename rbd_device->id
The "id" field of an rbd device structure represents the unique
client-local device id mapped to the underlying rbd image.  Each rbd
image will have another id--the image id--and each snapshot has its
own id as well.  The simple name "id" no longer conveys the
information one might like to have.

Rename the device "id" field in struct rbd_dev to be "dev_id" to
make it a little more obvious what we're dealing with without having
to think more about context.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:49 -07:00
Alex Elder 8e94af8e2b rbd: encapsulate header validity test
If an rbd image header is read and it doesn't begin with the
expected magic information, a warning is displayed.  This is
a fairly simple test, but it could be extended at some point.
Fix the comparison so it actually looks at the "text" field
rather than the front of the structure.

In any case, encapsulate the validity test in its own function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:48 -07:00
Alex Elder bd919d45aa rbd: clean up a few dout() calls
There was a dout() call in rbd_do_request() that was reporting
the reporting the offset as the length and vice versa.  While
fixing that I did a quick scan of other dout() calls and fixed
a couple of other minor things.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:46 -07:00
Alex Elder a059329056 rbd: simplify __rbd_remove_all_snaps()
This just replaces a while loop with list_for_each_entry_safe()
in __rbd_remove_all_snaps().

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:45 -07:00
Alex Elder a66f8c97a3 rbd: drop extra header_rwsem init
In commit c666601a there was inadvertently added an extra
initialization of rbd_dev->header_rwsem.  This gets rid of the
duplicate.

Reported-by: Guangliang Zhao <gzhao@suse.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
2012-07-30 18:15:45 -07:00
Alex Elder 9e15dc735a rbd: kill rbd_image_header->snap_seq
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>
2012-07-30 18:15:44 -07:00
Alex Elder 505cbb9bed rbd: set snapc->seq only when refreshing header
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>
2012-07-30 18:15:43 -07:00
Alex Elder 78dc447d3c rbd: preserve snapc->seq in rbd_header_set_snap()
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>
2012-07-30 18:15:42 -07:00
Alex Elder 75fe9e1981 rbd: don't use snapc->seq that way
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>
2012-07-30 18:15:41 -07:00
Josh Durgin a71b891bc7 rbd: send header version when notifying
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>
2012-07-30 18:15:40 -07:00
Josh Durgin d1d2564654 rbd: use reference counting for the snap context
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>
2012-07-30 18:15:40 -07:00
Josh Durgin 93a24e084d rbd: set image size when header is updated
The image may have been resized.

Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
2012-07-30 18:15:39 -07:00
Josh Durgin a51aa0c042 rbd: expose the correct size of the device in sysfs
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>
2012-07-30 18:15:38 -07:00
Josh Durgin 474ef7ce83 rbd: only reset capacity when pointing to head
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>
2012-07-30 18:15:37 -07:00
Josh Durgin e88a36ec96 rbd: return errors for mapped but deleted snapshot
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>
2012-07-30 18:15:36 -07:00
Alex Elder d1f57ea663 rbd: kill num_reply parameters
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>
2012-07-30 09:30:09 -07:00
Alex Elder 43ae470112 rbd: option symbol renames
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>
2012-07-30 09:30:08 -07:00
Alex Elder aded07ea9f rbd: more symbol renames
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>
2012-07-30 09:30:07 -07:00
Alex Elder 0bed54dc9a rbd: rename some fields in struct rbd_dev
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>
2012-07-30 09:30:06 -07:00
Alex Elder 0ce1a79413 rbd: use rbd_dev consistently
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>
2012-07-30 09:30:05 -07:00
Alex Elder 820a5f3e94 rbd: dynamically allocate snapshot name
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>
2012-07-30 09:30:04 -07:00
Alex Elder bf3e5ae112 rbd: dynamically allocate image name
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>
2012-07-30 09:30:04 -07:00
Alex Elder cb8627c76d rbd: dynamically allocate image header name
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>
2012-07-30 09:30:03 -07:00