[PATCH] ocfs2: Alloc at least a page for the DLM hash
The OCFS2 DLM allocates a number of pages for a hash to lookup locks.
There was a bug where a PAGE_SIZE bigger than the hash size (eg, 64K
pages) would result in zero pages allocated.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 0378ddb..4fc1be3 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -37,8 +37,12 @@
#define DLM_THREAD_SHUFFLE_INTERVAL 5 // flush everything every 5 passes
#define DLM_THREAD_MS 200 // flush at least every 200 ms
-#define DLM_HASH_SIZE (1 << 14)
-#define DLM_HASH_PAGES (DLM_HASH_SIZE / PAGE_SIZE)
+#define DLM_HASH_SIZE_DEFAULT (1 << 14)
+#if DLM_HASH_SIZE_DEFAULT < PAGE_SIZE
+# define DLM_HASH_PAGES 1
+#else
+# define DLM_HASH_PAGES (DLM_HASH_SIZE_DEFAULT / PAGE_SIZE)
+#endif
#define DLM_BUCKETS_PER_PAGE (PAGE_SIZE / sizeof(struct hlist_head))
#define DLM_HASH_BUCKETS (DLM_HASH_PAGES * DLM_BUCKETS_PER_PAGE)
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 80b8cce..a074ec6 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -67,6 +67,9 @@
for (i = 0; i < pages; i++)
if (!(vec[i] = (void *)__get_free_page(GFP_KERNEL)))
goto out_free;
+
+ mlog(0, "Allocated DLM hash pagevec; %d pages (%lu expected), %Zd buckets per page\n",
+ pages, DLM_HASH_PAGES, DLM_BUCKETS_PER_PAGE);
return vec;
out_free:
dlm_free_pagevec(vec, i);