Add support for the format change of MClientReply/MclientCaps.
Also add code that denies access to inodes with pool_ns layouts.

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

Cap message from MDS can update i_size. In that case, we don't
hold i_mutex. So it's unsafe to directly access inode->i_size
while holding i_mutex.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

The variant pagep will still get the invalid page point, although ceph
fails in function ceph_update_writeable_page.

To fix this issue, Assigne the page to pagep until there is no failure
in function ceph_update_writeable_page.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
Signed-off-by: Yan, Zheng <zyan@redhat.com>

ceph_update_writeable_page() unlocks the page on errors, so
page_mkwrite() should not unlock the page again.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

There are many places which use mapping_gfp_mask to restrict a more
generic gfp mask which would be used for allocations which are not
directly related to the page cache but they are performed in the same
context.

Let's introduce a helper function which makes the restriction explicit and
easier to track.  This patch doesn't introduce any functional changes.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull Ceph update from Sage Weil:
 "There are a few fixes for snapshot behavior with CephFS and support
  for the new keepalive protocol from Zheng, a libceph fix that affects
  both RBD and CephFS, a few bug fixes and cleanups for RBD from Ilya,
  and several small fixes and cleanups from Jianpeng and others"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: improve readahead for file holes
  ceph: get inode size for each append write
  libceph: check data_len in ->alloc_msg()
  libceph: use keepalive2 to verify the mon session is alive
  rbd: plug rbd_dev->header.object_prefix memory leak
  rbd: fix double free on rbd_dev->header_name
  libceph: set 'exists' flag for newly up osd
  ceph: cleanup use of ceph_msg_get
  ceph: no need to get parent inode in ceph_open
  ceph: remove the useless judgement
  ceph: remove redundant test of head->safe and silence static analysis warnings
  ceph: fix queuing inode to mdsdir's snaprealm
  libceph: rename con_work() to ceph_con_workfn()
  libceph: Avoid holding the zero page on ceph_msgr_slab_init errors
  libceph: remove the unused macro AES_KEY_SIZE
  ceph: invalidate dirty pages after forced umount
  ceph: EIO all operations after forced umount

With two exceptions (drm/qxl and drm/radeon) all vm_operations_struct
structs should be constant.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When readahead encounters file holes, osd reply returns error -ENOENT,
finish_read() skips adding pages to the the page cache. So readahead
does not work for file holes. The fix is adding zero pages to the
page cache when -ENOENT is returned.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

After forced umount, ceph_writepages_start() skips flushing dirty
pages. To make sure inode's reference count get dropped to zero,
we need to invalidate dirty pages.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

This patch makes try_get_cap_refs() and __do_request() check
if the file system was forced umount, and return -EIO if it was.
This patch also adds a helper function to drops dirty caps and
wakes up blocking operation.

Signed-off-by: Yan, Zheng <zyan@redhat.com>