linux-stable.git/drivers/block/rbd.c, branch linux-4.9.y

rbd: require global CAP_SYS_ADMIN for mapping and unmapping

2020-09-23T06:46:12+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

2020-09-12T09:47:36+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: don't return 0 on unmap if RBD_DEV_FLAG_REMOVING is set

2019-01-16T21:12:32+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

2018-07-03T09:23:16+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: silence bogus -Wmaybe-uninitialized warning

2018-02-25T10:05:54+00:00

commit d4c2269b3d5d06a8ea434b1841fbcaec336ed396 upstream.

drivers/block/rbd.c: In function ‘rbd_watch_cb’:
drivers/block/rbd.c:3690:5: error: ‘struct_v’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/block/rbd.c:3759:5: note: ‘struct_v’ was declared here

Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

rbd: set max_segments to USHRT_MAX

2018-01-17T08:38:54+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: use GFP_NOIO for parent stat and data requests

2017-11-15T14:53:20+00:00

commit 1e37f2f84680fa7f8394fd444b6928e334495ccc upstream.

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.

Link: http://tracker.ceph.com/issues/22014
Signed-off-by: Ilya Dryomov 
Reviewed-by: David Disseldorp 
Signed-off-by: Greg Kroah-Hartman

rbd: don't retry watch reregistration if header object is gone

2016-10-15T21:22:09+00:00

If the header object gets deleted (perhaps along with the entire pool),
there is no point in attempting to reregister the watch.  Treat this
the same as blacklisting: fail all pending and new I/Os requiring the
lock.

Signed-off-by: Ilya Dryomov

rbd: don't wait for the lock forever if blacklisted

2016-10-15T21:21:56+00:00

-EBLACKLISTED from __rbd_register_watch() means that our ceph_client
got blacklisted - we won't be able to restore the watch and reacquire
the lock.  Wake up and fail all outstanding requests waiting for the
lock and arrange for all new requests that require the lock to fail
immediately.

Signed-off-by: Ilya Dryomov 
Tested-by: Mike Christie

Merge tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client

2016-10-10T20:52:05+00:00

Pull Ceph updates from Ilya Dryomov:
 "The big ticket item here is support for rbd exclusive-lock feature,
  with maintenance operations offloaded to userspace (Douglas Fuller,
  Mike Christie and myself). Another block device bullet is a series
  fixing up layering error paths (myself).

  On the filesystem side, we've got patches that improve our handling of
  buffered vs dio write races (Neil Brown) and a few assorted fixes from
  Zheng. Also included a couple of random cleanups and a minor CRUSH
  update"

* tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client: (39 commits)
  crush: remove redundant local variable
  crush: don't normalize input of crush_ln iteratively
  libceph: ceph_build_auth() doesn't need ceph_auth_build_hello()
  libceph: use CEPH_AUTH_UNKNOWN in ceph_auth_build_hello()
  ceph: fix description for rsize and rasize mount options
  rbd: use kmalloc_array() in rbd_header_from_disk()
  ceph: use list_move instead of list_del/list_add
  ceph: handle CEPH_SESSION_REJECT message
  ceph: avoid accessing / when mounting a subpath
  ceph: fix mandatory flock check
  ceph: remove warning when ceph_releasepage() is called on dirty page
  ceph: ignore error from invalidate_inode_pages2_range() in direct write
  ceph: fix error handling of start_read()
  rbd: add rbd_obj_request_error() helper
  rbd: img_data requests don't own their page array
  rbd: don't call rbd_osd_req_format_read() for !img_data requests
  rbd: rework rbd_img_obj_exists_submit() error paths
  rbd: don't crash or leak on errors in rbd_img_obj_parent_read_full_callback()
  rbd: move bumping img_request refcount into rbd_obj_request_submit()
  rbd: mark the original request as done if stat request fails
  ...