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>
Define constant symbols related to the rbd format 2 object names.
This begins to bring this version of the "rbd_types.h" header
more in line with the current user-space version of that file.
Complete reconciliation of differences will be done at some
point later, as a separate task.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In the on-disk image header structure there is a field "block_name"
which represents what we now call the "object prefix" for an rbd
image. Rename this field "object_prefix" to be consistent with
modern usage.
This appears to be the only remaining vestige of the use of "block"
in symbols that represent objects in the rbd code.
This addresses http://tracker.newdream.net/issues/1761
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Dan Mick <dan.mick@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>
Here is another set of small code tidy-ups:
- Define SECTOR_SHIFT and SECTOR_SIZE, and use these symbolic
names throughout. Tell the blk_queue system our physical
block size, in the (unlikely) event we want to use something
other than the default.
- Delete the definition of struct rbd_info, which is never used.
- Move the definition of dev_to_rbd() down in its source file,
just above where it gets first used, and change its name to
dev_to_rbd_dev().
- Replace an open-coded operation in rbd_dev_release() to use
dev_to_rbd_dev() instead.
- Calculate the segment size for a given rbd_device just once in
rbd_init_disk().
- Use the '%zd' conversion specifier in rbd_snap_size_show(),
since the value formatted is a size_t.
- Switch to the '%llu' conversion specifier in rbd_snap_id_show().
since the value formatted is unsigned.
Signed-off-by: Alex Elder <elder@dreamhost.com>
The rados block device (rbd), based on osdblk, creates a block device
that is backed by objects stored in the Ceph distributed object storage
cluster. Each device consists of a single metadata object and data
striped over many data objects.
The rbd driver supports read-only snapshots.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Alex Elder