ebiederm@xmission.com (Eric W. Biederman) wrote:

Andrew Morton [off-list ref] writes:

quoted

ebiederm@xmission.com (Eric W. Biederman) wrote:

quoted

I can't imagine it being useful to guys like oracle without MAP_SHARED
support....

MAP_SHARED is supported.  I haven't tested it much though.

Given that none of the standard kernel idioms to prevent races in
this kind of code are present, I would be very surprised if it
was not racy.

- inode->i_sem is not taken to protect inode->i_size.

OK, I'll fix that up.

- After successfully allocating a page, a test is not made to see if
  another process with the same mapping has allocated the page first.

In this case, add_to_page_cache() in hugetlb_prefault() will return -EEXIST,
and the page which lost the race will be freed again.

Uh, but we don't establish a pte against the page which got there first. 
I'll fix that up too.  Thanks.
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