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authorMikulas Patocka <mpatocka@redhat.com>2023-10-31 19:12:54 +0100
committerMike Snitzer <snitzer@kernel.org>2023-10-31 14:25:06 -0400
commit9793c269da6cd339757de6ba5b2c8681b54c99af (patch)
tree6c71b9965930e7307d5431500ae3627dbaad1e3b /drivers/md
parent070bb43ab01e891db1b742d4ddd7291c7f8d7022 (diff)
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dm crypt: account large pages in cc->n_allocated_pages
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>
Diffstat (limited to 'drivers/md')
-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 4b5c54d0c51a..37dcc113baa1 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1692,11 +1692,17 @@ 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--;
}
@@ -1734,10 +1740,13 @@ 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);
+ }
}
}
}