Pull Ceph updates from Sage Weil:
 "There is the long-awaited discard support for RBD (Guangliang Zhao,
  Josh Durgin), a pile of RBD bug fixes that didn't belong in late -rc's
  (Ilya Dryomov, Li RongQing), a pile of fs/ceph bug fixes and
  performance and debugging improvements (Yan, Zheng, John Spray), and a
  smattering of cleanups (Chao Yu, Fabian Frederick, Joe Perches)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (40 commits)
  ceph: fix divide-by-zero in __validate_layout()
  rbd: rbd workqueues need a resque worker
  libceph: ceph-msgr workqueue needs a resque worker
  ceph: fix bool assignments
  libceph: separate multiple ops with commas in debugfs output
  libceph: sync osd op definitions in rados.h
  libceph: remove redundant declaration
  ceph: additional debugfs output
  ceph: export ceph_session_state_name function
  ceph: include the initial ACL in create/mkdir/mknod MDS requests
  ceph: use pagelist to present MDS request data
  libceph: reference counting pagelist
  ceph: fix llistxattr on symlink
  ceph: send client metadata to MDS
  ceph: remove redundant code for max file size verification
  ceph: remove redundant io_iter_advance()
  ceph: move ceph_find_inode() outside the s_mutex
  ceph: request xattrs if xattr_version is zero
  rbd: set the remaining discard properties to enable support
  rbd: use helpers to handle discard for layered images correctly
  ...

Pull pivot_root() fix from Andy Lutomirski.

Prevent a leak of unreachable mounts.

* 'CVE-2014-7970' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux:
  mnt: Prevent pivot_root from creating a loop in the mount tree

Andy Lutomirski recently demonstrated that when chroot is used to set
the root path below the path for the new ``root'' passed to pivot_root
the pivot_root system call succeeds and leaks mounts.

In examining the code I see that starting with a new root that is
below the current root in the mount tree will result in a loop in the
mount tree after the mounts are detached and then reattached to one
another.  Resulting in all kinds of ugliness including a leak of that
mounts involved in the leak of the mount loop.

Prevent this problem by ensuring that the new mount is reachable from
the current root of the mount tree.

[Added stable cc.  Fixes CVE-2014-7970.  --Andy]

Cc: stable@vger.kernel.org
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Reviewed-by: NAndy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/87bnpmihks.fsf@x220.int.ebiederm.orgSigned-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>

The 'stripe_unit' field is 64 bits, casting it to 32 bits can result zero.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Need to use WQ_MEM_RECLAIM for our workqueues to prevent I/O lockups
under memory pressure - we sit on the memory reclaim path.

Cc: stable@vger.kernel.org # 3.17, needs backporting for 3.16
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>
Tested-by: NMicha Krause <micha@krausam.de>
Reviewed-by: NSage Weil <sage@redhat.com>

Commit f363e45f ("net/ceph: make ceph_msgr_wq non-reentrant")
effectively removed WQ_MEM_RECLAIM flag from ceph_msgr_wq.  This is
wrong - libceph is very much a memory reclaim path, so restore it.

Cc: stable@vger.kernel.org # needs backporting for < 3.12
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>
Tested-by: NMicha Krause <micha@krausam.de>
Reviewed-by: NSage Weil <sage@redhat.com>

Fix some coccinelle warnings:
fs/ceph/caps.c:2400:6-10: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2401:6-15: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2402:6-17: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2403:6-22: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2404:6-22: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2405:6-19: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2440:4-20: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2469:3-16: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2490:2-18: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2519:3-7: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2549:3-12: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2575:2-6: WARNING: Assignment of bool to 0/1
fs/ceph/caps.c:2589:3-7: WARNING: Assignment of bool to 0/1
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>

For requests with multiple ops, separate ops with commas instead of \t,
which is a field separator here.
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Bring in missing osd ops and strings, use macros to eliminate multiple
points of maintenance.
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

ceph_release_page_vector was defined twice in libceph.h
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Signed-off-by: NIlya Dryomov <idryomov@redhat.com>

MDS session state and client global ID is
useful instrumentation when testing.
Signed-off-by: NJohn Spray <john.spray@redhat.com>

...so that it can be used from the ceph debugfs
code when dumping session info.
Signed-off-by: NJohn Spray <john.spray@redhat.com>

Current code set new file/directory's initial ACL in a non-atomic
manner.
Client first sends request to MDS to create new file/directory, then set
the initial ACL after the new file/directory is successfully created.

The fix is include the initial ACL in create/mkdir/mknod MDS requests.
So MDS can handle creating file/directory and setting the initial ACL in
one request.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Current code uses page array to present MDS request data. Pages in the
array are allocated/freed by caller of ceph_mdsc_do_request(). If request
is interrupted, the pages can be freed while they are still being used by
the request message.

The fix is use pagelist to present MDS request data. Pagelist is
reference counted.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

this allow pagelist to present data that may be sent multiple times.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

only regular file and directory have vxattrs.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Implement version 2 of CEPH_MSG_CLIENT_SESSION syntax,
which includes additional client metadata to allow
the MDS to report on clients by user-sensible names
like hostname.
Signed-off-by: NJohn Spray <john.spray@redhat.com>
Reviewed-by: NYan, Zheng <zyan@redhat.com>

Both ceph_update_writeable_page and ceph_setattr will verify file size
with max size ceph supported.
There are two caller for ceph_update_writeable_page, ceph_write_begin and
ceph_page_mkwrite. For ceph_write_begin, we have already verified the size in
generic_write_checks of ceph_write_iter; for ceph_page_mkwrite, we have no
chance to change file size when mmap. Likewise we have already verified the size
in inode_change_ok when we call ceph_setattr.
So let's remove the redundant code for max file size verification.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Reviewed-by: NYan, Zheng <zyan@redhat.com>

ceph_sync_read and generic_file_read_iter() have already advanced the
IO iterator.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_find_inode() may wait on freeing inode, using it inside the s_mutex
may cause deadlock. (the freeing inode is waiting for OSD read reply, but
dispatch thread is blocked by the s_mutex)
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Following sequence of events can happen.
  - Client releases an inode, queues cap release message.
  - A 'lookup' reply brings the same inode back, but the reply
    doesn't contain xattrs because MDS didn't receive the cap release
    message and thought client already has up-to-data xattrs.

The fix is force sending a getattr request to MDS if xattrs_version
is 0. The getattr mask is set to CEPH_STAT_CAP_XATTR, so MDS knows client
does not have xattr.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

max_discard_sectors must be set for the queue to support discard.
Operations implementing discard for rbd zero data, so report that.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Only allocate two osd ops for discard requests, since the
preallocation hint is only added for regular writes.  Use
rbd_img_obj_request_fill() to recreate the original write or discard
osd operations, isolating that logic to one place, and change the
assert in rbd_osd_req_create_copyup() to accept discard requests as
well.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

rbd_img_request_fill() creates a ceph_osd_request and has logic for
adding the appropriate osd ops to it based on the request type and
image properties.

For layered images, the original rbd_obj_request is resent with a
copyup operation in front, using a new ceph_osd_request. The logic for
adding the original operations should be the same as when first
sending them, so move it to a helper function.

op_type only needs to be checked once, so create a helper for that as
well and call it outside the loop in rbd_img_request_fill().
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Discard requests are a form of write, so they should go through the
same process as plain write requests and trigger copy-on-write for
layered images.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Discard may try to delete an object from a non-layered image that does not exist.
If this occurs, the image already has no data in that range, so change the
result to success.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Discards take a reference to the snapshot context of an image when
they are created.  This reference needs to be cleaned up when the
request is done just as it is for regular writes.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

In rbd_img_request_fill() the image size is only checked to determine
whether we can truncate an object instead of zeroing it for discard
requests. Take rbd_dev->header_rwsem while reading the image size, and
move this read into the discard check, so that non-discard ops don't
need to take the semaphore in this function.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

This patch add the discard support for rbd driver.

There are three types operation in the driver:
1. The objects would be removed if they completely contained
   within the discard range.
2. The objects would be truncated if they partly contained within
   the discard range, and align with their boundary.
3. Others would be zeroed.

A discard request from blkdev_issue_discard() is defined which
REQ_WRITE and REQ_DISCARD both marked and no data, so we must
check the REQ_DISCARD first when getting the request type.

This resolve:
	http://tracker.ceph.com/issues/190

[ Ilya Dryomov: This is incomplete and somewhat buggy, see follow up
  commits by Josh Durgin for refinements and fixes which weren't
  folded in to preserve authorship. ]
Signed-off-by: NGuangliang Zhao <lucienchao@gmail.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

It could only handle the read and write operations now,
extend it for the coming discard support.
Signed-off-by: NGuangliang Zhao <lucienchao@gmail.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

It need to copyup the parent's content when layered writing,
but an entire object write would overwrite it, so skip it.
Signed-off-by: NGuangliang Zhao <lucienchao@gmail.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

To clarify the conditions and make it easier to add new ones.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>

These fields may both change while the image is mapped if a snapshot
is created or deleted or the image is resized.  They are guarded by
rbd_dev->header_rwsem, so hold that while reading them, and store a
local copy to refer to outside of the critical section. The local copy
will stay consistent since the snapshot context is reference counted,
and the mapping size is just a u64. This prevents torn loads from
giving us inconsistent values.

Move reading header.snapc into the caller of rbd_img_request_create()
so that we only need to take the semaphore once. The read-only caller,
rbd_parent_request_create() can just pass NULL for snapc, since the
snapshot context is only relevant for writes.
Signed-off-by: NJosh Durgin <josh.durgin@inktank.com>

Trying to map an image out of a pool for which we don't have an 'x'
permission bit fails with -ERANGE from ceph_extract_encoded_string()
due to an unsigned vs signed bug.  Fix it and get rid of the -EINVAL
sink, thus propagating rbd::get_id cls method errors.  (I've seen
a bunch of unexplained -ERANGE reports, I bet this is it).
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

queue_work() doesn't "fail to queue", it returns false if work was
already on a queue, which can't happen here since we allocate
event_work right before we queue it.  So don't bother at all.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

we may corrupt waiting list if a request in the waiting list is kicked.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Use the more common pr_warn.

Other miscellanea:

o Coalesce formats
o Realign arguments
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>

So the recovering MDS does not need to fetch these ununsed inodes during
cache rejoin. This may reduce MDS recovery time.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

If the state variable is krealloced successfully, map->osd_state will be
freed, once following two reallocation failed, and exit the function
without resetting map->osd_state, map->osd_state become a wild pointer.

fix it by resetting them after krealloc successfully.
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>