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| author | Jongseok Kim <ks77sj@gmail.com> | 2018-09-05 09:21:47 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2018-09-11 08:03:16 +1000 |
| commit | 4f353ce03bbf769f0356eb9e9a2ca21466794f18 (patch) | |
| tree | 5008f22b7fdcf1a57552f9dcac9717a5cc51adbf | |
| parent | 99c3f5c159ec3f48efd4ea80d4cd96a5f6e0f9d0 (diff) | |
| download | linux-4f353ce03bbf769f0356eb9e9a2ca21466794f18.tar.gz linux-4f353ce03bbf769f0356eb9e9a2ca21466794f18.tar.xz | |
mm/z3fold.c: fix wrong handling of headless pages
During the processing of headless pages in z3fold_reclaim_page(), there
was a problem that the zhdr pointed to another page or a page was already
released in z3fold_free(). So, the wrong page is encoded in headless, or
test_bit does not work properly in z3fold_reclaim_page(). This patch
fixed these problems.
Link: http://lkml.kernel.org/r/1530853846-30215-1-git-send-email-ks77sj@gmail.com
Signed-off-by: Jongseok Kim <ks77sj@gmail.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
| -rw-r--r-- | mm/z3fold.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/mm/z3fold.c b/mm/z3fold.c index 4b366d181f35..201a8ac6342e 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -746,6 +746,9 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle) } if (bud == HEADLESS) { + if (test_bit(UNDER_RECLAIM, &page->private)) + return; + spin_lock(&pool->lock); list_del(&page->lru); spin_unlock(&pool->lock); @@ -836,20 +839,20 @@ static int z3fold_reclaim_page(struct z3fold_pool *pool, unsigned int retries) } list_for_each_prev(pos, &pool->lru) { page = list_entry(pos, struct page, lru); + zhdr = page_address(page); if (test_bit(PAGE_HEADLESS, &page->private)) /* candidate found */ break; - zhdr = page_address(page); if (!z3fold_page_trylock(zhdr)) continue; /* can't evict at this point */ kref_get(&zhdr->refcount); list_del_init(&zhdr->buddy); zhdr->cpu = -1; - set_bit(UNDER_RECLAIM, &page->private); break; } + set_bit(UNDER_RECLAIM, &page->private); list_del_init(&page->lru); spin_unlock(&pool->lock); @@ -898,6 +901,7 @@ next: if (test_bit(PAGE_HEADLESS, &page->private)) { if (ret == 0) { free_z3fold_page(page); + atomic64_dec(&pool->pages_nr); return 0; } spin_lock(&pool->lock); |