kernel/linux.git/drivers/block/rbd.c, branch v4.14.263

rbd: require global CAP_SYS_ADMIN for mapping and unmapping

2020-09-23T08:46:30+00:00

commit f44d04e696feaf13d192d942c4f14ad2e117065a upstream. 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 Signed-off-by: Greg Kroah-Hartman

block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into

2020-09-09T17:03:12+00:00

commit 233bde21aa43516baa013ef7ac33f3427056db3e upstream. It happens often while I'm preparing a patch for a block driver that I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT available for this driver? Do I have to introduce definitions of these constants before I can use these constants? To avoid this confusion, move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the header file such that these become available for all block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h header file conditional to avoid that including that header file after causes the compiler to complain about a SECTOR_SIZE redefinition. Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have not been removed from uapi header files nor from NAND drivers in which these constants are used for another purpose than converting block layer offsets and sizes into a number of sectors. Cc: David S. Miller Cc: Mike Snitzer Cc: Dan Williams Cc: Minchan Kim Cc: Nitin Gupta Reviewed-by: Sergey Senozhatsky Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Martin K. Petersen Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

rbd: call rbd_dev_unprobe() after unwatching and flushing notifies

2020-04-24T06:01:16+00:00

[ Upstream commit 952c48b0ed18919bff7528501e9a3fff8a24f8cd ] 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 Signed-off-by: Sasha Levin

rbd: avoid a deadlock on header_rwsem when flushing notifies

2020-04-24T06:01:14+00:00

[ Upstream commit 0e4e1de5b63fa423b13593337a27fd2d2b0bcf77 ] 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 Signed-off-by: Sasha Levin

rbd: don't return 0 on unmap if RBD_DEV_FLAG_REMOVING is set

2019-01-16T21:07:12+00:00

commit 85f5a4d666fd9be73856ed16bb36c5af5b406b29 upstream. There is a window between when RBD_DEV_FLAG_REMOVING is set and when the device is removed from rbd_dev_list. During this window, we set "already" and return 0. Returning 0 from write(2) can confuse userspace tools because 0 indicates that nothing was written. In particular, "rbd unmap" will retry the write multiple times a second: 10:28:05.463299 write(4, "0", 1) = 0 10:28:05.463509 write(4, "0", 1) = 0 10:28:05.463720 write(4, "0", 1) = 0 10:28:05.463942 write(4, "0", 1) = 0 10:28:05.464155 write(4, "0", 1) = 0 Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Tested-by: Dongsheng Yang Signed-off-by: Greg Kroah-Hartman

rbd: flush rbd_dev->watch_dwork after watch is unregistered

2018-07-03T09:25:03+00:00

commit 23edca864951250af845a11da86bb3ea63522ed2 upstream. There is a problem if we are going to unmap a rbd device and the watch_dwork is going to queue delayed work for watch: unmap Thread watch Thread timer do_rbd_remove cancel_tasks_sync(rbd_dev) queue_delayed_work for watch destroy_workqueue(rbd_dev->task_wq) drain_workqueue(wq) destroy other resources in wq call_timer_fn __queue_work() Then the delayed work escape the cancel_tasks_sync() and destroy_workqueue() and we will get an user-after-free call trace: BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI Modules linked in: CPU: 7 PID: 0 Comm: swapper/7 Tainted: G OE 4.17.0-rc6+ #13 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__queue_work+0x6a/0x3b0 RSP: 0018:ffff9427df1c3e90 EFLAGS: 00010086 RAX: ffff9427deca8400 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff9427deca8400 RSI: ffff9427df1c3e50 RDI: 0000000000000000 RBP: ffff942783e39e00 R08: ffff9427deca8400 R09: ffff9427df1c3f00 R10: 0000000000000004 R11: 0000000000000005 R12: ffff9427cfb85970 R13: 0000000000002000 R14: 000000000001eca0 R15: 0000000000000007 FS: 0000000000000000(0000) GS:ffff9427df1c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000004c900a005 CR4: 00000000000206e0 Call Trace: ? __queue_work+0x3b0/0x3b0 call_timer_fn+0x2d/0x130 run_timer_softirq+0x16e/0x430 ? tick_sched_timer+0x37/0x70 __do_softirq+0xd2/0x280 irq_exit+0xd5/0xe0 smp_apic_timer_interrupt+0x6c/0x130 apic_timer_interrupt+0xf/0x20 [ Move rbd_dev->watch_dwork cancellation so that rbd_reregister_watch() either bails out early because the watch is UNREGISTERED at that point or just gets cancelled. ] Cc: stable@vger.kernel.org Fixes: 99d1694310df ("rbd: retry watch re-registration periodically") Signed-off-by: Dongsheng Yang Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

rbd: whitelist RBD_FEATURE_OPERATIONS feature bit

2018-02-22T14:42:28+00:00

commit e573427a440fd67d3f522357d7ac901d59281948 upstream. This feature bit restricts older clients from performing certain maintenance operations against an image (e.g. clone, snap create). krbd does not perform maintenance operations. Cc: stable@vger.kernel.org Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Signed-off-by: Greg Kroah-Hartman

rbd: set max_segments to USHRT_MAX

2018-01-17T08:45:23+00:00

commit 21acdf45f4958135940f0b4767185cf911d4b010 upstream. Commit d3834fefcfe5 ("rbd: bump queue_max_segments") bumped max_segments (unsigned short) to max_hw_sectors (unsigned int). max_hw_sectors is set to the number of 512-byte sectors in an object and overflows unsigned short for 32M (largest possible) objects, making the block layer resort to handing us single segment (i.e. single page or even smaller) bios in that case. Fixes: d3834fefcfe5 ("rbd: bump queue_max_segments") Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman

rbd: reacquire lock should update lock owner client id

2018-01-17T08:45:23+00:00

commit edd8ca8015800b354453b891d38960f3a474b7e4 upstream. Otherwise, future operations on this RBD using exclusive-lock are going to require the lock from a non-existent client id. Fixes: 14bb211d324d ("rbd: support updating the lock cookie without releasing the lock") Link: http://tracker.ceph.com/issues/19929 Signed-off-by: Florian Margaine [idryomov@gmail.com: rbd_set_owner_cid() call, __rbd_lock() helper] Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman

rbd: use GFP_NOIO for parent stat and data requests

2017-11-09T08:32:53+00:00

rbd_img_obj_exists_submit() and rbd_img_obj_parent_read_full() are on the writeback path for cloned images -- we attempt a stat on the parent object to see if it exists and potentially read it in to call copyup. GFP_NOIO should be used instead of GFP_KERNEL here. Cc: stable@vger.kernel.org Link: http://tracker.ceph.com/issues/22014 Signed-off-by: Ilya Dryomov Reviewed-by: David Disseldorp