I don't think that I quite follow the logic. The dirtying from write()The problems will start, when you have a file that is both mapped andPerhaps I didn't understand what page_mapped() does, but it does seem toBecause there's no way to know inside the set_page_dirty() functions+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?
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.
have the right semantics as far as I could see.
modified with write(). Then the dirying from the write() will set the
flag, and that will have undesirable consequences.
will set the flag, but then the mtime will get updated and the flag will
be cleared by the hook in file_update_time(). Right?
Take this example:
fd = open()
addr = mmap(.., fd)
The file times will be updated in write(), but with your patch, the
bit in the mapping will also be set.
Then in msync() the file times will be updated again, which is wrong,
since the memory was _not_ modified through the mapping.