block_invalidatepage — invalidate part or all of a buffer-backed page
void block_invalidatepage ( | struct page * page, |
| unsigned int offset, | |
unsigned int length); |
struct page * pagethe page which is affected
unsigned int offsetstart of the range to invalidate
unsigned int lengthlength of the range to invalidate
block_invalidatepage is called when all or part of the page has become
invalidated by a truncate operation.
block_invalidatepage does not have to release all buffers, but it must
ensure that no dirty buffer is left outside offset and that no I/O
is underway against any of the blocks which are outside the truncation
point. Because the caller is about to free (and possibly reuse) those
blocks on-disk.