[PATCH 3.11 181/208] dm bufio: initialize read-only module parameters
Luis Henriques
luis.henriques at canonical.com
Thu Dec 19 11:54:39 UTC 2013
3.11.10.2 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Mikulas Patocka <mpatocka at redhat.com>
commit 4cb57ab4a2e61978f3a9b7d4f53988f30d61c27f upstream.
Some module parameters in dm-bufio are read-only. These parameters
inform the user about memory consumption. They are not supposed to be
changed by the user.
However, despite being read-only, these parameters can be set on
modprobe or insmod command line, for example:
modprobe dm-bufio current_allocated_bytes=12345
The kernel doesn't expect that these variables can be non-zero at module
initialization and if the user sets them, it results in BUG.
This patch initializes the variables in the module init routine, so that
user-supplied values are ignored.
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
drivers/md/dm-bufio.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 5227e07..dcb867c 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1703,6 +1703,11 @@ static int __init dm_bufio_init(void)
{
__u64 mem;
+ dm_bufio_allocated_kmem_cache = 0;
+ dm_bufio_allocated_get_free_pages = 0;
+ dm_bufio_allocated_vmalloc = 0;
+ dm_bufio_current_allocated = 0;
+
memset(&dm_bufio_caches, 0, sizeof dm_bufio_caches);
memset(&dm_bufio_cache_names, 0, sizeof dm_bufio_cache_names);
--
1.8.3.2
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