On Fri, May 27, 2016 at 12:06 PM, Vitaly Wool <vitalywool@xxxxxxxxx> wrote:
> This patch fixes erroneous z3fold header access in a HEADLESS page
> in reclaim function, and changes one remaining direct
> handle-to-buddy conversion to use the appropriate helper.
>
> Signed-off-by: Vitaly Wool <vitalywool@xxxxxxxxx>
Reviewed-by: Dan Streetman <ddstreet@xxxxxxxx>
> ---
> mm/z3fold.c | 24 ++++++++++++++----------
> 1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index 34917d5..8f9e89c 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -412,7 +412,7 @@ static void z3fold_free(struct z3fold_pool *pool,
> unsigned long handle)
> /* HEADLESS page stored */
> bud = HEADLESS;
> } else {
> - bud = (handle - zhdr->first_num) & BUDDY_MASK;
> + bud = handle_to_buddy(handle);
> switch (bud) {
> case FIRST:
> @@ -572,15 +572,19 @@ next:
> pool->pages_nr--;
> spin_unlock(&pool->lock);
> return 0;
> - } else if (zhdr->first_chunks != 0 &&
> - zhdr->last_chunks != 0 && zhdr->middle_chunks !=
> 0) {
> - /* Full, add to buddied list */
> - list_add(&zhdr->buddy, &pool->buddied);
> - } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
> - z3fold_compact_page(zhdr);
> - /* add to unbuddied list */
> - freechunks = num_free_chunks(zhdr);
> - list_add(&zhdr->buddy,
> &pool->unbuddied[freechunks]);
> + } else if (!test_bit(PAGE_HEADLESS, &page->private)) {
> + if (zhdr->first_chunks != 0 &&
> + zhdr->last_chunks != 0 &&
> + zhdr->middle_chunks != 0) {
> + /* Full, add to buddied list */
> + list_add(&zhdr->buddy, &pool->buddied);
> + } else {
> + z3fold_compact_page(zhdr);
> + /* add to unbuddied list */
> + freechunks = num_free_chunks(zhdr);
> + list_add(&zhdr->buddy,
> + &pool->unbuddied[freechunks]);
> + }
> }
> /* add to beginning of LRU */
> --
> 2.5.0
>
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