linux-toradex.git/drivers, branch v3.12.47

rbd: fix copyup completion race

2015-08-25T14:57:11+00:00

commit 2761713d35e370fd640b5781109f753066b746c4 upstream.

For write/discard obj_requests that involved a copyup method call, the
opcode of the first op is CEPH_OSD_OP_CALL and the ->callback is
rbd_img_obj_copyup_callback().  The latter frees copyup pages, sets
->xferred and delegates to rbd_img_obj_callback(), the "normal" image
object callback, for reporting to block layer and putting refs.

rbd_osd_req_callback() however treats CEPH_OSD_OP_CALL as a trivial op,
which means obj_request is marked done in rbd_osd_trivial_callback(),
*before* ->callback is invoked and rbd_img_obj_copyup_callback() has
a chance to run.  Marking obj_request done essentially means giving
rbd_img_obj_callback() a license to end it at any moment, so if another
obj_request from the same img_request is being completed concurrently,
rbd_img_obj_end_request() may very well be called on such prematurally
marked done request:


handle_reply()
  rbd_osd_req_callback()
    rbd_osd_trivial_callback()
    rbd_obj_request_complete()
    rbd_img_obj_copyup_callback()
    rbd_img_obj_callback()
                                    
                                    handle_reply()
                                      rbd_osd_req_callback()
                                        rbd_osd_trivial_callback()
      for_each_obj_request(obj_request->img_request) {
        rbd_img_obj_end_request(obj_request-1/2)
        rbd_img_obj_end_request(obj_request-2/2) <--
      }

Calling rbd_img_obj_end_request() on such a request leads to trouble,
in particular because its ->xfferred is 0.  We report 0 to the block
layer with blk_update_request(), get back 1 for "this request has more
data in flight" and then trip on

    rbd_assert(more ^ (which == img_request->obj_request_count));

with rhs (which == ...) being 1 because rbd_img_obj_end_request() has
been called for both requests and lhs (more) being 1 because we haven't
got a chance to set ->xfferred in rbd_img_obj_copyup_callback() yet.

To fix this, leverage that rbd wants to call class methods in only two
cases: one is a generic method call wrapper (obj_request is standalone)
and the other is a copyup (obj_request is part of an img_request).  So
make a dedicated handler for CEPH_OSD_OP_CALL and directly invoke
rbd_img_obj_copyup_callback() from it if obj_request is part of an
img_request, similar to how CEPH_OSD_OP_READ handler invokes
rbd_img_obj_request_read_callback().

Since rbd_img_obj_copyup_callback() is now being called from the OSD
request callback (only), it is renamed to rbd_osd_copyup_callback().

Cc: Alex Elder 
Signed-off-by: Ilya Dryomov 
Reviewed-by: Alex Elder 
[idryomov@gmail.com: backport to < 3.18: context]
Signed-off-by: Jiri Slaby

EDAC, ppc4xx: Access mci->csrows array elements properly

2015-08-25T14:57:10+00:00

commit 5c16179b550b9fd8114637a56b153c9768ea06a5 upstream.

The commit

  de3910eb79ac ("edac: change the mem allocation scheme to
		 make Documentation/kobject.txt happy")

changed the memory allocation for the csrows member. But ppc4xx_edac was
forgotten in the patch. Fix it.

Signed-off-by: Michael Walle 
Cc: linux-edac 
Cc: Mauro Carvalho Chehab 
Link: http://lkml.kernel.org/r/1437469253-8611-1-git-send-email-michael@walle.cc
Signed-off-by: Borislav Petkov 
Signed-off-by: Jiri Slaby

dm thin metadata: delete btrees when releasing metadata snapshot

2015-08-25T14:57:09+00:00

commit 7f518ad0a212e2a6fd68630e176af1de395070a7 upstream.

The device details and mapping trees were just being decremented
before.  Now btree_del() is called to do a deep delete.

Signed-off-by: Joe Thornber 
Signed-off-by: Mike Snitzer 
Signed-off-by: Jiri Slaby

xen-blkfront: don't add indirect pages to list when !feature_persistent

2015-08-25T14:57:08+00:00

commit 7b0767502b5db11cb1f0daef2d01f6d71b1192dc upstream.

We should consider info->feature_persistent when adding indirect page to list
info->indirect_pages, else the BUG_ON() in blkif_free() would be triggered.

When we are using persistent grants the indirect_pages list
should always be empty because blkfront has pre-allocated enough
persistent pages to fill all requests on the ring.

Acked-by: Roger Pau Monné 
Signed-off-by: Bob Liu 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Jiri Slaby

md/bitmap: return an error when bitmap superblock is corrupt.

2015-08-25T14:57:05+00:00

commit b97e92574c0bf335db1cd2ec491d8ff5cd5d0b49 upstream
    Use separate bitmaps for each nodes in the cluster

bitmap_read_sb() validates the bitmap superblock that it reads in.
If it finds an inconsistency like a bad magic number or out-of-range
version number, it prints an error and returns, but it incorrectly
returns zero, so the array is still assembled with the (invalid) bitmap.

This means it could try to use a bitmap with a new version number which
it therefore does not understand.

This bug was introduced in 3.5 and fix as part of a larger patch in 4.1.
So the patch is suitable for any -stable kernel in that range.

Fixes: 27581e5ae01f ("md/bitmap: centralise allocation of bitmap file pages.")
Signed-off-by: NeilBrown 
Reported-by: GuoQing Jiang

md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies

2015-08-25T14:56:56+00:00

commit 423f04d63cf421ea436bcc5be02543d549ce4b28 upstream.

raid1_end_read_request() assumes that the In_sync bits are consistent
with the ->degaded count.
raid1_spare_active updates the In_sync bit before the ->degraded count
and so exposes an inconsistency, as does error()
So extend the spinlock in raid1_spare_active() and error() to hide those
inconsistencies.

This should probably be part of
  Commit: 34cab6f42003 ("md/raid1: fix test for 'was read error from
  last working device'.")
as it addresses the same issue.  It fixes the same bug and should go
to -stable for same reasons.

Fixes: 76073054c95b ("md/raid1: clean up read_balance.")
Signed-off-by: NeilBrown 
Signed-off-by: Jiri Slaby

iscsi-target: Fix iscsit_start_kthreads failure OOPs

2015-08-25T14:56:54+00:00

commit e54198657b65625085834847ab6271087323ffea upstream.

This patch fixes a regression introduced with the following commit
in v4.0-rc1 code, where a iscsit_start_kthreads() failure triggers
a NULL pointer dereference OOPs:

    commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca
    Author: Nicholas Bellinger 
    Date:   Thu Feb 26 22:19:15 2015 -0800

        iscsi-target: Convert iscsi_thread_set usage to kthread.h

To address this bug, move iscsit_start_kthreads() immediately
preceeding the transmit of last login response, before signaling
a successful transition into full-feature-phase within existing
iscsi_target_do_tx_login_io() logic.

This ensures that no target-side resource allocation failures can
occur after the final login response has been successfully sent.

Also, it adds a iscsi_conn->rx_login_comp to allow the RX thread
to sleep to prevent other socket related failures until the final
iscsi_post_login_handler() call is able to complete.

Cc: Sagi Grimberg 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Jiri Slaby

crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer

2015-08-25T14:56:53+00:00

commit f898c522f0e9ac9f3177d0762b76e2ab2d2cf9c0 upstream.

This patch removes a bogus BUG_ON in the ablkcipher path that
triggers when the destination buffer is different from the source
buffer and is scattered.

Signed-off-by: Herbert Xu 
Signed-off-by: Jiri Slaby

md: use kzalloc() when bitmap is disabled

2015-08-19T06:36:51+00:00

commit b6878d9e03043695dbf3fa1caa6dfc09db225b16 upstream.

In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a
mdu_bitmap_file_t called "file".

5769         file = kmalloc(sizeof(*file), GFP_NOIO);
5770         if (!file)
5771                 return -ENOMEM;

This structure is copied to user space at the end of the function.

5786         if (err == 0 &&
5787             copy_to_user(arg, file, sizeof(*file)))
5788                 err = -EFAULT

But if bitmap is disabled only the first byte of "file" is initialized
with zero, so it's possible to read some bytes (up to 4095) of kernel
space memory from user space. This is an information leak.

5775         /* bitmap disabled, zero the first byte and copy out */
5776         if (!mddev->bitmap_info.file)
5777                 file->pathname[0] = '\0';

Signed-off-by: Benjamin Randazzo 
Signed-off-by: NeilBrown 
Signed-off-by: Jiri Slaby

ipmi: fix timeout calculation when bmc is disconnected

2015-08-19T06:36:51+00:00

commit e21404dc0ac7ac971c1e36274b48bb460463f4e5 upstream.

Loading ipmi_si module while bmc is disconnected, we found the timeout
is longer than 5 secs.  Actually it takes about 3 mins and 20
secs.(HZ=250)

error message as below:
  Dec 12 19:08:59 linux kernel: IPMI BT: timeout in RD_WAIT [ ] 1 retries left
  Dec 12 19:08:59 linux kernel: BT: write 4 bytes seq=0x01 03 18 00 01
  [...]
  Dec 12 19:12:19 linux kernel: IPMI BT: timeout in RD_WAIT [ ]
  Dec 12 19:12:19 linux kernel: failed 2 retries, sending error response
  Dec 12 19:12:19 linux kernel: IPMI: BT reset (takes 5 secs)
  Dec 12 19:12:19 linux kernel: IPMI BT: flag reset [ ]

Function wait_for_msg_done() use schedule_timeout_uninterruptible(1) to
sleep 1 tick, so we should subtract jiffies_to_usecs(1) instead of 100
usecs from timeout.

Reported-by: Hu Shiyuan 
Signed-off-by: Xie XiuQi 
Signed-off-by: Corey Minyard 
Signed-off-by: Linus Torvalds 
Signed-off-by: Jiri Slaby