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authorMiaohe Lin <linmiaohe@huawei.com>2021-06-30 18:52:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-06-30 20:47:31 -0700
commit46b76f2e09dc35f70aca2f4349eb0d158f53fe93 (patch)
tree5e9f3a7fb3da7b6415d3a20f9608693871a02568
parentae34af1f11d0a6ae849b7605d15df9798dab7b46 (diff)
downloadlinux-46b76f2e09dc35f70aca2f4349eb0d158f53fe93.tar.bz2
mm/zswap.c: fix two bugs in zswap_writeback_entry()
In the ZSWAP_SWAPCACHE_FAIL and ZSWAP_SWAPCACHE_EXIST case, we forgot to call zpool_unmap_handle() when zpool can't sleep. And we might sleep in zswap_get_swap_cache_page() while zpool can't sleep. To fix all of these, zpool_unmap_handle() should be done before zswap_get_swap_cache_page() when zpool can't sleep. Link: https://lkml.kernel.org/r/20210522092242.3233191-4-linmiaohe@huawei.com Fixes: fc6697a89f56 ("mm/zswap: add the flag can_sleep_mapped") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Seth Jennings <sjenning@redhat.com> Cc: Tian Tao <tiantao6@hisilicon.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/zswap.c17
1 files changed, 7 insertions, 10 deletions
diff --git a/mm/zswap.c b/mm/zswap.c
index c27ce9f2cdf8..7944e3e57e78 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -967,6 +967,13 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
spin_unlock(&tree->lock);
BUG_ON(offset != entry->offset);
+ src = (u8 *)zhdr + sizeof(struct zswap_header);
+ if (!zpool_can_sleep_mapped(pool)) {
+ memcpy(tmp, src, entry->length);
+ src = tmp;
+ zpool_unmap_handle(pool, handle);
+ }
+
/* try to allocate swap cache page */
switch (zswap_get_swap_cache_page(swpentry, &page)) {
case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */
@@ -982,17 +989,7 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
case ZSWAP_SWAPCACHE_NEW: /* page is locked */
/* decompress */
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
-
dlen = PAGE_SIZE;
- src = (u8 *)zhdr + sizeof(struct zswap_header);
-
- if (!zpool_can_sleep_mapped(pool)) {
-
- memcpy(tmp, src, entry->length);
- src = tmp;
-
- zpool_unmap_handle(pool, handle);
- }
mutex_lock(acomp_ctx->mutex);
sg_init_one(&input, src, entry->length);