>On Thu, Jul 11, 2013 at 3:53 PM, majianpeng <[email protected]> wrote: >>>On Thu, Jul 11, 2013 at 9:17 AM, majianpeng <[email protected]> wrote: >>>> Although, mmap-write of ceph update the time of file using >>>> file_update_time.Because it don't mark the relative cap so the time >>>> can't save. >>> >>>I think cephfs' mmap IO support is still broken. mmap IO does not respect >>>ceph capabilities at all. It's possible that the kclient has no Fw cap when >>>ceph_page_mkwrite is called. >>> >>>Yan, Zheng >>> >>> >> Hi Yan, >> For the read of mmap, i think we also add cap-check. >> And i think we can rewrite the filemap_fault ect ceph_filemap_fault. >> In ceph_filemap_fault, most code from filemap_fault, we only add cap-check >> for read-operation. >> How about this or can you suggest anthor method? >> > >This doesn't work. if a file is opened by multiple clients, the MDS >doesn't issue Fcb caps to the client. >If we add cap check to filemap_fault and page_mkwrite, they can block >forever. To make mmap IO work >properly, I think the only solution is introducing a new cache >coherence protocol for mmap IO > Thanks your suggestion. Unless we get the Fcb cap, we can do the mmap-io.How about this? Because the cap can change,so we can using Fx to lock the file, so cap can't change.
> >> Thanks! >> Jianpeng Ma
