linux.git/drivers/block, branch v3.10.100

xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing)

2015-11-09T18:12:58+00:00

commit a54c8f0f2d7df525ff997e2afe71866a1a013064 upstream.

xen-blkfront will crash if the check to talk_to_blkback()
in blkback_changed()(XenbusStateInitWait) returns an error.
The driver data is freed and info is set to NULL. Later during
the close process via talk_to_blkback's call to xenbus_dev_fatal()
the null pointer is passed to and dereference in blkfront_closing.

Signed-off-by: Cathy Avery 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

rbd: prevent kernel stack blow up on rbd map

2015-11-09T18:12:58+00:00

commit 6d69bb536bac0d403d83db1ca841444981b280cd upstream.

Mapping an image with a long parent chain (e.g. image foo, whose parent
is bar, whose parent is baz, etc) currently leads to a kernel stack
overflow, due to the following recursion in the reply path:

  rbd_osd_req_callback()
    rbd_obj_request_complete()
      rbd_img_obj_callback()
        rbd_img_parent_read_callback()
          rbd_obj_request_complete()
            ...

Limit the parent chain to 16 images, which is ~5K worth of stack.  When
the above recursion is eliminated, this limit can be lifted.

Fixes: http://tracker.ceph.com/issues/12538

Signed-off-by: Ilya Dryomov 
Reviewed-by: Josh Durgin 
[idryomov@gmail.com: backport to 3.10: rbd_dev->opts, context]
Signed-off-by: Greg Kroah-Hartman

rbd: don't leak parent_spec in rbd_dev_probe_parent()

2015-11-09T18:12:58+00:00

commit 1f2c6651f69c14d0d3a9cfbda44ea101b02160ba upstream.

Currently we leak parent_spec and trigger a "parent reference
underflow" warning if rbd_dev_create() in rbd_dev_probe_parent() fails.
The problem is we take the !parent out_err branch and that only drops
refcounts; parent_spec that would've been freed had we called
rbd_dev_unparent() remains and triggers rbd_warn() in
rbd_dev_parent_put() - at that point we have parent_spec != NULL and
parent_ref == 0, so counter ends up being -1 after the decrement.

Redo rbd_dev_probe_parent() to fix this.

Signed-off-by: Ilya Dryomov 
[idryomov@gmail.com: backport to < 4.2: rbd_dev->opts]
Reviewed-by: Alex Elder 
Signed-off-by: Greg Kroah-Hartman

rbd: require stable pages if message data CRCs are enabled

2015-11-09T18:12:58+00:00

commit bae818ee1577c27356093901a0ea48f672eda514 upstream.

rbd requires stable pages, as it performs a crc of the page data before
they are send to the OSDs.

But since kernel 3.9 (patch 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0
"mm: only enforce stable page writes if the backing device requires
it") it is not assumed anymore that block devices require stable pages.

This patch sets the necessary flag to get stable pages back for rbd.

In a ceph installation that provides multiple ext4 formatted rbd
devices "bad crc" messages appeared regularly (ca 1 message every 1-2
minutes on every OSD that provided the data for the rbd) in the
OSD-logs before this patch. After this patch this messages are pretty
much gone (only ca 1-2 / month / OSD).

Signed-off-by: Ronny Hegewald 
[idryomov@gmail.com: require stable pages only in crc case, changelog]
[idryomov@gmail.com: backport to 3.9-3.17: context]
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

rbd: fix double free on rbd_dev->header_name

2015-10-27T00:44:51+00:00

commit 3ebe138ac642a195c7f2efdb918f464734421fd6 upstream.

If rbd_dev_image_probe() in rbd_dev_probe_parent() fails, header_name
is freed twice: once in rbd_dev_probe_parent() and then in its caller
rbd_dev_image_probe() (rbd_dev_image_probe() is called recursively to
handle parent images).

rbd_dev_probe_parent() is responsible for probing the parent, so it
shouldn't muck with clone's fields.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Alex Elder 
Signed-off-by: Greg Kroah-Hartman

rbd: fix copyup completion race

2015-08-17T03:51:39+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 
Signed-off-by: Greg Kroah-Hartman

rbd: use GFP_NOIO in rbd_obj_request_create()

2015-08-03T16:29:47+00:00

commit 5a60e87603c4c533492c515b7f62578189b03c9c upstream.

rbd_obj_request_create() is called on the main I/O path, so we need to
use GFP_NOIO to make sure allocation doesn't blow back on us.  Not all
callers need this, but I'm still hardcoding the flag inside rather than
making it a parameter because a) this is going to stable, and b) those
callers shouldn't really use rbd_obj_request_create() and will be fixed
in the future.

More memory allocation fixes will follow.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Alex Elder 
Signed-off-by: Greg Kroah-Hartman

rbd: end I/O the entire obj_request on error

2015-05-13T12:15:41+00:00

commit 082a75dad84d79d1c15ea9e50f31cb4bb4fa7fd6 upstream.

When we end I/O struct request with error, we need to pass
obj_request->length as @nr_bytes so that the entire obj_request worth
of bytes is completed.  Otherwise block layer ends up confused and we
trip on

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

in rbd_img_obj_callback() due to more being true no matter what.  We
already do it in most cases but we are missing some, in particular
those where we don't even get a chance to submit any obj_requests, due
to an early -ENOMEM for example.

A number of obj_request->xferred assignments seem to be redundant but
I haven't touched any of obj_request->xferred stuff to keep this small
and isolated.

Cc: Alex Elder 
Reported-by: Shawn Edwards 
Reviewed-by: Sage Weil 
Signed-off-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman

nbd: fix possible memory leak

2015-04-19T08:10:47+00:00

commit ff6b8090e26ef7649ef0cc6b42389141ef48b0cf upstream.

we have already allocated memory for nbd_dev, but we were not
releasing that memory and just returning the error value.

Signed-off-by: Sudip Mukherjee 
Acked-by: Paul Clements 
Signed-off-by: Markus Pargmann 
Signed-off-by: Greg Kroah-Hartman

rbd: drop an unsafe assertion

2015-02-27T01:48:49+00:00

commit 638c323c4d1f8eaf25224946e21ce8818f1bcee1 upstream.

Olivier Bonvalet reported having repeated crashes due to a failed
assertion he was hitting in rbd_img_obj_callback():

    Assertion failure in rbd_img_obj_callback() at line 2165:
	rbd_assert(which >= img_request->next_completion);

With a lot of help from Olivier with reproducing the problem
we were able to determine the object and image requests had
already been completed (and often freed) at the point the
assertion failed.

There was a great deal of discussion on the ceph-devel mailing list
about this.  The problem only arose when there were two (or more)
object requests in an image request, and the problem was always
seen when the second request was being completed.

The problem is due to a race in the window between setting the
"done" flag on an object request and checking the image request's
next completion value.  When the first object request completes, it
checks to see if its successor request is marked "done", and if
so, that request is also completed.  In the process, the image
request's next_completion value is updated to reflect that both
the first and second requests are completed.  By the time the
second request is able to check the next_completion value, it
has been set to a value *greater* than its own "which" value,
which caused an assertion to fail.

Fix this problem by skipping over any completion processing
unless the completing object request is the next one expected.
Test only for inequality (not >=), and eliminate the bad
assertion.

Tested-by: Olivier Bonvalet 
Signed-off-by: Alex Elder 
Reviewed-by: Sage Weil 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Greg Kroah-Hartman