Messages in this thread |  | | Date | Thu, 22 Feb 2007 15:14:57 -0500 | From | Peter Staubach <> | Subject | Re: [PATCH] update ctime and mtime for mmaped write |
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Miklos Szeredi wrote: >>>> Why is the flag checked in __fput()? >>>> >>>> >>> It's because of this bit in the standard: >>> >>> If there is no such call and if the underlying file is modified >>> as a result of a write reference, then these fields shall be >>> marked for update at some time after the write reference. >>> >>> It could be done in munmap/mremap, but it seemed more difficult to >>> track down all the places where the vma is removed. But yes, that may >>> be a nicer solution. >>> >> It seems to me that, with this support, a file, which is mmap'd, >> modified, but never msync'd or munmap'd, will never get its mtime >> updated. Or did I miss that? >> >> I also don't see how an mmap'd block device will get its mtime >> updated either. >> > > __fput() will be called when there are no more references to 'file', > then it will update the time if the flag is set. This applies to > regular files as well as devices. > >
I suspect that you will find that, for a block device, the wrong inode gets updated. That's where the bd_inode_update_time() portion of my proposed patch came from.
> But I've moved the check from __fput to remove_vma() in the next > revision of the patch, which would give slightly nicer semantics, and > be equally conforming.
This still does not address the situation where a file is 'permanently' mmap'd, does it?
Thanx...
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