LU-16637 llite: call truncate_inode_pages() in inode lock

LU-16637 llite: call truncate_inode_pages() in inode lock

In some cases vvp_prune()->truncate_inode_pages() is get called
without IO context, we need protect it with inode lock as well.

So we add ll_inode_info::lli_inode_lock_owner and set it according to
vfs lock rules (Documentation/filesystems/Locking or
Documentation/filesystems/locking.rst), so before calling
truncate_inode_pages(), we'd lock the inode if it's not locked in
vfs.

Lustre-commit: 51d62f2122fee14fbb3ff8333b5a830e1181e4e5
Lustre-change: https://review.whamcloud.com/50857

Fixes: ef9be34478 ("LU-16637 llite: call truncate_inode_pages() under inode lock")
Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I84d7d999a49325810062a9a7337e184d35467820
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51643
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>