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  1. 05 6月, 2013 1 次提交
  3. 08 5月, 2013 1 次提交
  5. 07 5月, 2013 1 次提交
  7. 19 4月, 2013 1 次提交
    • R
      xen-block: implement indirect descriptors · 402b27f9
      由 Roger Pau Monne 提交于 
      Indirect descriptors introduce a new block operation
(BLKIF_OP_INDIRECT) that passes grant references instead of segments
in the request. This grant references are filled with arrays of
blkif_request_segment_aligned, this way we can send more segments in a
request.

The proposed implementation sets the maximum number of indirect grefs
(frames filled with blkif_request_segment_aligned) to 256 in the
backend and 32 in the frontend. The value in the frontend has been
chosen experimentally, and the backend value has been set to a sane
value that allows expanding the maximum number of indirect descriptors
in the frontend if needed.

The migration code has changed from the previous implementation, in
which we simply remapped the segments on the shared ring. Now the
maximum number of segments allowed in a request can change depending
on the backend, so we have to requeue all the requests in the ring and
in the queue and split the bios in them if they are bigger than the
new maximum number of segments.

[v2: Fixed minor comments by Konrad.
[v1: Added padding to make the indirect request 64bit aligned.
 Added some BUGs, comments; fixed number of indirect pages in
 blkif_get_x86_{32/64}_req. Added description about the indirect operation
 in blkif.h]
Signed-off-by: NRoger Pau Monné <roger.pau@citrix.com>
[v3: Fixed spaces and tabs mix ups]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      402b27f9
  9. 18 4月, 2013 6 次提交
  11. 08 4月, 2013 1 次提交
    • J
      Revert "loop: cleanup partitions when detaching loop device" · c2fccc1c
      由 Jens Axboe 提交于 
      This reverts commit 8761a3dc.

There are situations where the destruction path is called
with the bdev->bd_mutex already held, which then deadlocks in
loop_clr_fd(). The normal partition cleanup does a trylock()
on the mutex, but it'd be nice to have a more bullet proof
method in loop. So punt this more involved fix to the next
merge window, and just back out this buggy fix for now.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      c2fccc1c
  13. 04 4月, 2013 4 次提交
  15. 02 4月, 2013 1 次提交
    • A
      loop: prevent bdev freeing while device in use · c1681bf8
      由 Anatol Pomozov 提交于 
      struct block_device lifecycle is defined by its inode (see fs/block_dev.c) -
block_device allocated first time we access /dev/loopXX and deallocated on
bdev_destroy_inode. When we create the device "losetup /dev/loopXX afile"
we want that block_device stay alive until we destroy the loop device
with "losetup -d".

But because we do not hold /dev/loopXX inode its counter goes 0, and
inode/bdev can be destroyed at any moment. Usually it happens at memory
pressure or when user drops inode cache (like in the test below). When later in
loop_clr_fd() we want to use bdev we have use-after-free error with following
stack:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000280
  bd_set_size+0x10/0xa0
  loop_clr_fd+0x1f8/0x420 [loop]
  lo_ioctl+0x200/0x7e0 [loop]
  lo_compat_ioctl+0x47/0xe0 [loop]
  compat_blkdev_ioctl+0x341/0x1290
  do_filp_open+0x42/0xa0
  compat_sys_ioctl+0xc1/0xf20
  do_sys_open+0x16e/0x1d0
  sysenter_dispatch+0x7/0x1a

To prevent use-after-free we need to grab the device in loop_set_fd()
and put it later in loop_clr_fd().

The issue is reprodusible on current Linus head and v3.3. Here is the test:

  dd if=/dev/zero of=loop.file bs=1M count=1
  while [ true ]; do
    losetup /dev/loop0 loop.file
    echo 2 > /proc/sys/vm/drop_caches
    losetup -d /dev/loop0
  done

[ Doing bdgrab/bput in loop_set_fd/loop_clr_fd is safe, because every
  time we call loop_set_fd() we check that loop_device->lo_state is
  Lo_unbound and set it to Lo_bound If somebody will try to set_fd again
  it will get EBUSY.  And if we try to loop_clr_fd() on unbound loop
  device we'll get ENXIO.

  loop_set_fd/loop_clr_fd (and any other loop ioctl) is called under
  loop_device->lo_ctl_mutex. ]
Signed-off-by: NAnatol Pomozov <anatol.pomozov@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c1681bf8
  17. 30 3月, 2013 1 次提交
    • A
      rbd: don't zero-fill non-image object requests · 6e2a4505
      由 Alex Elder 提交于 
      A result of ENOENT from a read request for an object that's part of
an rbd image indicates that there is a hole in that portion of the
image.  Similarly, a short read for such an object indicates that
the remainder of the read should be interpreted a full read with
zeros filling out the end of the request.

This behavior is not correct for objects that are not backing rbd
image data.  Currently rbd_img_obj_request_callback() assumes it
should be done for all objects.

Change rbd_img_obj_request_callback() so it only does this zeroing
for image objects.  Encapsulate that special handling in its own
function.  Add an assertion that the image object request is a bio
request, since we assume that (and we currently don't support any
other types).

This resolves a problem identified here:
    http://tracker.ceph.com/issues/4559

The regression was introduced by bf0d5f50.
Reported-by: NDan van der Ster <dan@vanderster.com>
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-off-by: NSage Weil <sage@inktank.com>
      6e2a4505
  19. 29 3月, 2013 1 次提交
  21. 28 3月, 2013 1 次提交
  23. 27 3月, 2013 2 次提交
  25. 26 3月, 2013 1 次提交
  27. 23 3月, 2013 3 次提交
  29. 22 3月, 2013 2 次提交
  31. 20 3月, 2013 3 次提交
  33. 19 3月, 2013 4 次提交
  35. 16 3月, 2013 2 次提交
  37. 12 3月, 2013 4 次提交