[Cluster-devel] [PATCHv2 RESEND v5.10-rc2 03/13] fs: dlm: add get buffer error handling

[Alexander Aring <aahringo@redhat.com>]

This patch adds an error handling to the get buffer functionality if the
user is requesting a buffer length which is more than possible of
the internal buffer allocator. This should never happen because specific
handling decided by compile time, but will warn if somebody forget about
to handle this limitation right.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/lowcomms.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 77382c2ce6da..620eca3979d5 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -1352,6 +1352,12 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
 	struct writequeue_entry *e;
 	int offset = 0;
 
+	if (len > LOWCOMMS_MAX_TX_BUFFER_LEN) {
+		BUILD_BUG_ON(PAGE_SIZE < LOWCOMMS_MAX_TX_BUFFER_LEN);
+		log_print("failed to allocate a buffer of size %d", len);
+		return NULL;
+	}
+
 	con = nodeid2con(nodeid, allocation);
 	if (!con)
 		return NULL;
-- 
2.26.2