staging: zcache: fix possible sleep under lock
authorSeth Jennings <sjenning@linux.vnet.ibm.com>
Mon, 22 Aug 2011 19:30:38 +0000 (14:30 -0500)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 23 Aug 2011 21:49:33 +0000 (14:49 -0700)
zcache_new_pool() calls kmalloc() with GFP_KERNEL which has
__GFP_WAIT set.  However, zcache_new_pool() gets called on
a stack that holds the swap_lock spinlock, leading to a
possible sleep-with-lock situation. The lock is obtained
in enable_swap_info().

The patch replaces GFP_KERNEL with GFP_ATOMIC.

v2: replace with GFP_ATOMIC, not GFP_IOFS

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/staging/zcache/zcache-main.c

index 855a5bb56a47d8e591873b05e6be15ec6f4f6ee0..cdf0128fb55c98e9907a6fe4d3686472629edd1a 100644 (file)
@@ -1668,7 +1668,7 @@ static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
        if (cli == NULL)
                goto out;
        atomic_inc(&cli->refcount);
-       pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL);
+       pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC);
        if (pool == NULL) {
                pr_info("zcache: pool creation failed: out of memory\n");
                goto out;