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    mm: consistent truncate and invalidate loops · b85e0eff
    Hugh Dickins 提交于
    Make the pagevec_lookup loops in truncate_inode_pages_range(),
    invalidate_mapping_pages() and invalidate_inode_pages2_range() more
    consistent with each other.
    
    They were relying upon page->index of an unlocked page, but apologizing
    for it: accept it, embrace it, add comments and WARN_ONs, and simplify the
    index handling.
    
    invalidate_inode_pages2_range() had special handling for a wrapped
    page->index + 1 = 0 case; but MAX_LFS_FILESIZE doesn't let us anywhere
    near there, and a corrupt page->index in the radix_tree could cause more
    trouble than that would catch.  Remove that wrapped handling.
    
    invalidate_inode_pages2_range() uses min() to limit the pagevec_lookup
    when near the end of the range: copy that into the other two, although
    it's less useful than you might think (it limits the use of the buffer,
    rather than the indices looked up).
    Signed-off-by: NHugh Dickins <hughd@google.com>
    Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
    b85e0eff
filemap.c 69.4 KB