linux-stable.git/drivers/block, branch v5.4.13

xen/blkback: Avoid unmapping unmapped grant pages

2020-01-09T09:20:07+00:00

[ Upstream commit f9bd84a8a845d82f9b5a081a7ae68c98a11d2e84 ]

For each I/O request, blkback first maps the foreign pages for the
request to its local pages.  If an allocation of a local page for the
mapping fails, it should unmap every mapping already made for the
request.

However, blkback's handling mechanism for the allocation failure does
not mark the remaining foreign pages as unmapped.  Therefore, the unmap
function merely tries to unmap every valid grant page for the request,
including the pages not mapped due to the allocation failure.  On a
system that fails the allocation frequently, this problem leads to
following kernel crash.

  [  372.012538] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
  [  372.012546] IP: [] gnttab_unmap_refs.part.7+0x1c/0x40
  [  372.012557] PGD 16f3e9067 PUD 16426e067 PMD 0
  [  372.012562] Oops: 0002 [#1] SMP
  [  372.012566] Modules linked in: act_police sch_ingress cls_u32
  ...
  [  372.012746] Call Trace:
  [  372.012752]  [] gnttab_unmap_refs+0x34/0x40
  [  372.012759]  [] xen_blkbk_unmap+0x83/0x150 [xen_blkback]
  ...
  [  372.012802]  [] dispatch_rw_block_io+0x970/0x980 [xen_blkback]
  ...
  Decompressing Linux... Parsing ELF... done.
  Booting the kernel.
  [    0.000000] Initializing cgroup subsys cpuset

This commit fixes this problem by marking the grant pages of the given
request that didn't mapped due to the allocation failure as invalid.

Fixes: c6cc142dac52 ("xen-blkback: use balloon pages for all mappings")

Reviewed-by: David Woodhouse 
Reviewed-by: Maximilian Heyne 
Reviewed-by: Paul Durrant 
Reviewed-by: Roger Pau Monné 
Signed-off-by: SeongJae Park 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

xen-blkback: prevent premature module unload

2020-01-09T09:19:51+00:00

[ Upstream commit fa2ac657f9783f0891b2935490afe9a7fd29d3fa ]

Objects allocated by xen_blkif_alloc come from the 'blkif_cache' kmem
cache. This cache is destoyed when xen-blkif is unloaded so it is
necessary to wait for the deferred free routine used for such objects to
complete. This necessity was missed in commit 14855954f636 "xen-blkback:
allow module to be cleanly unloaded". This patch fixes the problem by
taking/releasing extra module references in xen_blkif_alloc/free()
respectively.

Signed-off-by: Paul Durrant 
Reviewed-by: Roger Pau Monné 
Signed-off-by: Juergen Gross 
Signed-off-by: Sasha Levin

nbd: fix shutdown and recv work deadlock v2

2019-12-31T15:46:34+00:00

commit 1c05839aa973cfae8c3db964a21f9c0eef8fcc21 upstream.

This fixes a regression added with:

commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4
Author: Mike Christie 
Date:   Sun Aug 4 14:10:06 2019 -0500

    nbd: fix max number of supported devs

where we can deadlock during device shutdown. The problem occurs if
the recv_work's nbd_config_put occurs after nbd_start_device_ioctl has
returned and the userspace app has droppped its reference via closing
the device and running nbd_release. The recv_work nbd_config_put call
would then drop the refcount to zero and try to destroy the config which
would try to do destroy_workqueue from the recv work.

This patch just has nbd_start_device_ioctl do a flush_workqueue when it
wakes so we know after the ioctl returns running works have exited. This
also fixes a possible race where we could try to reuse the device while
old recv_works are still running.

Cc: stable@vger.kernel.org
Fixes: e9e006f5fcf2 ("nbd: fix max number of supported devs")
Signed-off-by: Mike Christie 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: fix no-unmap write-zeroes request behavior

2019-12-31T15:44:31+00:00

[ Upstream commit efcfec579f6139528c9e6925eca2bc4a36da65c6 ]

Currently, if the loop device receives a WRITE_ZEROES request, it asks
the underlying filesystem to punch out the range.  This behavior is
correct if unmapping is allowed.  However, a NOUNMAP request means that
the caller doesn't want us to free the storage backing the range, so
punching out the range is incorrect behavior.

To satisfy a NOUNMAP | WRITE_ZEROES request, loop should ask the
underlying filesystem to FALLOC_FL_ZERO_RANGE, which is (according to
the fallocate documentation) required to ensure that the entire range is
backed by real storage, which suffices for our purposes.

Fixes: 19372e2769179dd ("loop: implement REQ_OP_WRITE_ZEROES")
Signed-off-by: Darrick J. Wong 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

nbd: prevent memory leak

2019-11-29T09:09:47+00:00

commit 03bf73c315edca28f47451913177e14cd040a216 upstream.

In nbd_add_socket when krealloc succeeds, if nsock's allocation fail the
reallocted memory is leak. The correct behaviour should be assigning the
reallocted memory to config->socks right after success.

Reviewed-by: Josef Bacik 
Signed-off-by: Navid Emamdoost 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'for-linus-20191121' of git://git.kernel.dk/linux-block

2019-11-21T20:04:50+00:00

Pull block fix from Jens Axboe:
 "Just a single fix for an issue in nbd introduced in this cycle"

* tag 'for-linus-20191121' of git://git.kernel.dk/linux-block:
  nbd:fix memory leak in nbd_get_socket()

nbd:fix memory leak in nbd_get_socket()

2019-11-19T16:23:26+00:00

Before returning NULL, put the sock first.

Cc: stable@vger.kernel.org
Fixes: cf1b2326b734 ("nbd: verify socket is supported during setup")
Reviewed-by: Josef Bacik 
Reviewed-by: Mike Christie 
Signed-off-by: Sun Ke 
Signed-off-by: Jens Axboe

Merge tag 'for-linus-20191115' of git://git.kernel.dk/linux-block

2019-11-15T21:02:34+00:00

Pull block fixes from Jens Axboe:
 "A few fixes that should make it into this release. This contains:

   - io_uring:
        - The timeout command assumes sequence == 0 means that we want
          one completion, but this kind of overloading is unfortunate as
          it prevents users from doing a pure time based wait. Since
          this operation was introduced in this cycle, let's correct it
          now, while we can. (me)
        - One-liner to fix an issue with dependent links and fixed
          buffer reads. The actual IO completed fine, but the link got
          severed since we stored the wrong expected value. (me)
        - Add TIMEOUT to list of opcodes that don't need a file. (Pavel)

   - rsxx missing workqueue destry calls. Old bug. (Chuhong)

   - Fix blk-iocost active list check (Jiufei)

   - Fix impossible-to-hit overflow merge condition, that still hit some
     folks very rarely (Junichi)

   - Fix bfq hang issue from 5.3. This didn't get marked for stable, but
     will go into stable post this merge (Paolo)"

* tag 'for-linus-20191115' of git://git.kernel.dk/linux-block:
  rsxx: add missed destroy_workqueue calls in remove
  iocost: check active_list of all the ancestors in iocg_activate()
  block, bfq: deschedule empty bfq_queues not referred by any process
  io_uring: ensure registered buffer import returns the IO length
  io_uring: Fix getting file for timeout
  block: check bi_size overflow before merge
  io_uring: make timeout sequence == 0 mean no sequence

rsxx: add missed destroy_workqueue calls in remove

2019-11-14T20:59:49+00:00

The driver misses calling destroy_workqueue in remove like what is done
when probe fails.
Add the missed calls to fix it.

Signed-off-by: Chuhong Yuan 
Signed-off-by: Jens Axboe

rbd: silence bogus uninitialized warning in rbd_object_map_update_finish()

2019-11-14T18:00:53+00:00

Some versions of gcc (so far 6.3 and 7.4) throw a warning:

  drivers/block/rbd.c: In function 'rbd_object_map_callback':
  drivers/block/rbd.c:2124:21: warning: 'current_state' may be used uninitialized in this function [-Wmaybe-uninitialized]
        (current_state == OBJECT_EXISTS && state == OBJECT_EXISTS_CLEAN))
  drivers/block/rbd.c:2092:23: note: 'current_state' was declared here
    u8 state, new_state, current_state;
                          ^~~~~~~~~~~~~

It's bogus because all current_state accesses are guarded by
has_current_state.

Reported-by: kbuild test robot 
Signed-off-by: Ilya Dryomov 
Reviewed-by: Dongsheng Yang