user/sven/linux.git/drivers/block/rbd.c, branch v5.9.2

rbd: require global CAP_SYS_ADMIN for mapping and unmapping

2020-09-07T11:14:30Z

It turns out that currently we rely only on sysfs attribute permissions: $ ll /sys/bus/rbd/{add*,remove*} --w------- 1 root root 4096 Sep 3 20:37 /sys/bus/rbd/add --w------- 1 root root 4096 Sep 3 20:37 /sys/bus/rbd/add_single_major --w------- 1 root root 4096 Sep 3 20:37 /sys/bus/rbd/remove --w------- 1 root root 4096 Sep 3 20:38 /sys/bus/rbd/remove_single_major This means that images can be mapped and unmapped (i.e. block devices can be created and deleted) by a UID 0 process even after it drops all privileges or by any process with CAP_DAC_OVERRIDE in its user namespace as long as UID 0 is mapped into that user namespace. Be consistent with other virtual block devices (loop, nbd, dm, md, etc) and require CAP_SYS_ADMIN in the initial user namespace for mapping and unmapping, and also for dumping the configuration string and refreshing the image header. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

treewide: Remove uninitialized_var() usage

2020-07-16T19:35:15Z

Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var$([^$]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook

libceph: move away from global osd_req_flags

2020-06-16T14:01:53Z

osd_req_flags is overly general and doesn't suit its only user (read_from_replica option) well: - applying osd_req_flags in account_request() affects all OSD requests, including linger (i.e. watch and notify). However, linger requests should always go to the primary even though some of them are reads (e.g. notify has side effects but it is a read because it doesn't result in mutation on the OSDs). - calls to class methods that are reads are allowed to go to the replica, but most such calls issued for "rbd map" and/or exclusive lock transitions are requested to be resent to the primary via EAGAIN, doubling the latency. Get rid of global osd_req_flags and set read_from_replica flag only on specific OSD requests instead. Fixes: 8ad44d5e0d1e ("libceph: read_from_replica option") Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

rbd: compression_hint option

2020-06-01T21:32:35Z

Allow hinting to bluestore if the data should/should not be compressed. The default is to not hint (compression_hint=none). Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

libceph: support for alloc hint flags

2020-06-01T21:32:35Z

Allow indicating future I/O pattern via flags. This is supported since Kraken (and bluestore persists flags together with expected_object_size and expected_write_size). Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

rbd: don't mess with a page vector in rbd_notify_op_lock()

2020-04-13T06:55:49Z

rbd_notify_op_lock() isn't interested in a notify reply. Instead of accepting that page vector just to free it, have watch-notify code take care of it. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

rbd: don't test rbd_dev->opts in rbd_dev_image_release()

2020-04-13T06:55:49Z

rbd_dev->opts is used to distinguish between the image that is being mapped and a parent. However, because we no longer establish watch for read-only mappings, this test is imprecise and results in unnecessary rbd_unregister_watch() calls. Make it consistent with need_watch in rbd_dev_image_probe(). Fixes: b9ef2b8858a0 ("rbd: don't establish watch for read-only mappings") Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

rbd: call rbd_dev_unprobe() after unwatching and flushing notifies

2020-04-13T06:55:49Z

rbd_dev_unprobe() is supposed to undo most of rbd_dev_image_probe(), including rbd_dev_header_info(), which means that rbd_dev_header_info() isn't supposed to be called after rbd_dev_unprobe(). However, rbd_dev_image_release() calls rbd_dev_unprobe() before rbd_unregister_watch(). This is racy because a header update notify can sneak in: "rbd unmap" thread ceph-watch-notify worker rbd_dev_image_release() rbd_dev_unprobe() free and zero out header rbd_watch_cb() rbd_dev_refresh() rbd_dev_header_info() read in header The same goes for "rbd map" because rbd_dev_image_probe() calls rbd_dev_unprobe() on errors. In both cases this results in a memory leak. Fixes: fd22aef8b47c ("rbd: move rbd_unregister_watch() call into rbd_dev_image_release()") Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

rbd: avoid a deadlock on header_rwsem when flushing notifies

2020-04-13T06:55:49Z

rbd_unregister_watch() flushes notifies and therefore cannot be called under header_rwsem because a header update notify takes header_rwsem to synchronize with "rbd map". If mapping an image fails after the watch is established and a header update notify sneaks in, we deadlock when erroring out from rbd_dev_image_probe(). Move watch registration and unregistration out of the critical section. The only reason they were put there was to make header_rwsem management slightly more obvious. Fixes: 811c66887746 ("rbd: fix rbd map vs notify races") Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman