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| author | Miaohe Lin <linmiaohe@huawei.com> | 2021-06-30 18:52:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-06-30 20:47:31 -0700 |
| commit | 46b76f2e09dc35f70aca2f4349eb0d158f53fe93 (patch) | |
| tree | 5e9f3a7fb3da7b6415d3a20f9608693871a02568 /mm | |
| parent | ae34af1f11d0a6ae849b7605d15df9798dab7b46 (diff) | |
| download | lwn-46b76f2e09dc35f70aca2f4349eb0d158f53fe93.tar.gz lwn-46b76f2e09dc35f70aca2f4349eb0d158f53fe93.zip | |
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/zswap.c | 17 |
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); |