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authorMikulas Patocka <mpatocka@redhat.com>2023-10-31 19:12:54 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-11-28 17:15:01 +0000
commite93ac6410de384421f6aca7fc1da4c4cd8e243ad (patch)
tree7660a06737cc1a09f5b00a5e9b975fe52d274588
parent369f7c467211d0edabf587c7e452dc2b8f5f0bec (diff)
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dm crypt: account large pages in cc->n_allocated_pages
commit 9793c269da6cd339757de6ba5b2c8681b54c99af upstream. The commit 5054e778fcd9c ("dm crypt: allocate compound pages if possible") changed dm-crypt to use compound pages to improve performance. Unfortunately, there was an oversight: the allocation of compound pages was not accounted at all. Normal pages are accounted in a percpu counter cc->n_allocated_pages and dm-crypt is limited to allocate at most 2% of memory. Because compound pages were not accounted at all, dm-crypt could allocate memory over the 2% limit. Fix this by adding the accounting of compound pages, so that memory consumption of dm-crypt is properly limited. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Fixes: 5054e778fcd9c ("dm crypt: allocate compound pages if possible") Cc: stable@vger.kernel.org # v6.5+ Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/md/dm-crypt.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index dc0463bf3c2c..0fadb656a215 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1700,11 +1700,17 @@ retry:
order = min(order, remaining_order);
while (order > 0) {
+ if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) +
+ (1 << order) > dm_crypt_pages_per_client))
+ goto decrease_order;
pages = alloc_pages(gfp_mask
| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
order);
- if (likely(pages != NULL))
+ if (likely(pages != NULL)) {
+ percpu_counter_add(&cc->n_allocated_pages, 1 << order);
goto have_pages;
+ }
+decrease_order:
order--;
}
@@ -1742,10 +1748,13 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
bio_for_each_folio_all(fi, clone) {
- if (folio_test_large(fi.folio))
+ if (folio_test_large(fi.folio)) {
+ percpu_counter_sub(&cc->n_allocated_pages,
+ 1 << folio_order(fi.folio));
folio_put(fi.folio);
- else
+ } else {
mempool_free(&fi.folio->page, &cc->page_pool);
+ }
}
}
}