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    SubjectRe: [PATCH] update ctime and mtime for mmaped write
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    > > Inspired by Peter Staubach's patch and the resulting comments.
    > >
    > >
    >
    > An updated version of the original patch was submitted to LKML
    > yesterday... :-)

    Strange coincidence :)

    > > file = vma->vm_file;
    > > start = vma->vm_end;
    > > + mapping_update_time(file);
    > > if ((flags & MS_SYNC) && file &&
    > > (vma->vm_flags & VM_SHARED)) {
    > > get_file(file);
    > >
    >
    > It seems to me that this might lead to file times being updated for
    > non-MAP_SHARED mappings.

    In theory no, because the COW-ed pages become anonymous and are not
    part of the original mapping any more.

    > > +int set_page_dirty_mapping(struct page *page);
    > >
    >
    > This aspect of the design seems intrusive to me. I didn't see a strong
    > reason to introduce new versions of many of the routines just to handle
    > these semantics. What motivated this part of your design? Why the new
    > _mapping versions of routines?

    Because there's no way to know inside the set_page_dirty() functions
    if the dirtying comes from a memory mapping or from a modification
    through a normal write(). And they have different semantics, for
    write() the modification times are updated immediately.

    Thanks,
    Miklos
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