kernel/git/stable/linux-stable.git/drivers/block/rbd.c, branch linux-5.5.y

rbd: work around -Wuninitialized warning

2020-02-24T07:38:44+00:00

[ Upstream commit a55e601b2f02df5db7070e9a37bd655c9c576a52 ] gcc -O3 warns about a dummy variable that is passed down into rbd_img_fill_nodata without being initialized: drivers/block/rbd.c: In function 'rbd_img_fill_nodata': drivers/block/rbd.c:2573:13: error: 'dummy' is used uninitialized in this function [-Werror=uninitialized] fctx->iter = *fctx->pos; Since this is a dummy, I assume the warning is harmless, but it's better to initialize it anyway and avoid the warning. Fixes: mmtom ("init/Kconfig: enable -O3 for all arches") Signed-off-by: Arnd Bergmann Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin

libceph, rbd, ceph: convert to use the new mount API

2019-11-27T21:28:37+00:00

Convert the ceph filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. [ Numerous string handling, leak and regression fixes; rbd conversion was particularly broken and had to be redone almost from scratch. ] Signed-off-by: David Howells Signed-off-by: Jeff Layton Signed-off-by: Ilya Dryomov

rbd: ask for a weaker incompat mask for read-only mappings

2019-11-25T10:44:03+00:00

For a read-only mapping, ask for a set of features that make the image only unwritable rather than both unreadable and unwritable by a client that doesn't understand them. As of today, the difference between them for krbd is journaling (JOURNALING) and live migration (MIGRATING). get_features method supports read_only parameter since hammer, ceph.git commit 6176ec5fde2a ("librbd: differentiate between R/O vs R/W RBD features"). Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: don't query snapshot features

2019-11-25T10:44:03+00:00

Since infernalis, ceph.git commit 281f87f9ee52 ("cls_rbd: get_features on snapshots returns HEAD image features"), querying and checking that is pointless. Userspace support for manipulating image features after image creation came also in infernalis, so a snapshot with a different set of features wasn't ever possible. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: remove snapshot existence validation code

2019-11-25T10:44:03+00:00

RBD_DEV_FLAG_EXISTS check in rbd_queue_workfn() is racy and leads to inconsistent behaviour. If the object (or its snapshot) isn't there, the OSD returns ENOENT. A read submitted before the snapshot removal notification is processed would be zero-filled and ended with status OK, while future reads would be failed with IOERR. It also doesn't handle a case when an image that is mapped read-only is removed. On top of this, because watch is no longer established for read-only mappings, we no longer get notifications, so rbd_exists_validate() is effectively dead code. While failing requests rather than returning zeros is a good thing, RBD_DEV_FLAG_EXISTS is not it. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: don't establish watch for read-only mappings

2019-11-25T10:44:03+00:00

With exclusive lock out of the way, watch is the only thing left that prevents a read-only mapping from being used with read-only OSD caps. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: don't acquire exclusive lock for read-only mappings

2019-11-25T10:44:03+00:00

A read-only mapping should be usable with read-only OSD caps, so neither the header lock nor the object map lock can be acquired. Unfortunately, this means that images mapped read-only lose the advantage of the object map. Snapshots, however, can take advantage of the object map without any exclusionary locks, so if the object map is desired, snapshot the image and map the snapshot instead of the image. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: disallow read-write partitions on images mapped read-only

2019-11-25T10:44:03+00:00

If an image is mapped read-only, don't allow setting its partition(s) to read-write via BLKROSET: with the previous patch all writes to such images are failed anyway. If an image is mapped read-write, its partition(s) can be set to read-only (and back to read-write) as before. Note that at the rbd level the image will remain writeable: anything sent down by the block layer will be executed, including any write from internal kernel users. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: treat images mapped read-only seriously

2019-11-25T10:44:02+00:00

Even though -o ro/-o read_only/--read-only options are very old, we have never really treated them seriously (on par with snapshots). As a first step, fail writes to images mapped read-only just like we do for snapshots. We need this check in rbd because the block layer basically ignores read-only setting, see commit a32e236eb93e ("Partially revert "block: fail op_is_write() requests to read-only partitions""). Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang

rbd: introduce RBD_DEV_FLAG_READONLY

2019-11-25T10:44:02+00:00

rbd_dev->opts is not available for parent images, making checking rbd_dev->opts->read_only in various places (rbd_dev_image_probe(), need_exclusive_lock(), use_object_map() in the following patches) harder than it needs to be. Keeping rbd_dev_image_probe() in mind, move the initialization in do_rbd_add() up. snap_id isn't filled in at that point, so replace rbd_is_snap() with a snap_name comparison. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Reviewed-by: Dongsheng Yang