ceph: handle partial result from get_user_pages
ceph: handle partial result from get_user_pages

The get_user_pages() helper can return fewer than the requested pages.
Error out in that case, and clean up the partial result.

Signed-off-by: Henry C Chang <8ea7691fbcfbc0c50d0799098007c03792365f76@tcloudcomputing.com>
Signed-off-by: Sage Weil <6dd34506bbd5e58221bbb3e4732d97c91f02277b@newdream.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs