libglusterfs: add gf_get_mem_type()

gfapi needs to provide a function towards applications to free memory
that it allocated. Depending on how the application is compiled/linked,
it could use a different memory allocator than Gluster itself. Therefore
it is not safe for gfapi to request applications to free memory with
'standard' free().

Examples for this are Gluster allocated structures with GF_CALLOC() when
memory accounting is enabled (the default). Some gfapi functions use
malloc() to allocate memory as a workaround, but the free() from the
jemalloc implementation should not be combined with the malloc() from
glibc.

Change-Id: I626cd1a60abf8965f9263290f4045d1f69fc2093
BUG: 1344714
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/15108
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: soumya k <skoduri@redhat.com>
Reviewed-by: jiffin tony Thottan <jthottan@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/libglusterfs/src/mem-pool.c b/libglusterfs/src/mem-pool.c
index 93a1415a75a..5f2851033ec 100644
--- a/libglusterfs/src/mem-pool.c
+++ b/libglusterfs/src/mem-pool.c
@@ -338,6 +338,27 @@ free:
 }
 
 
+/* Based on the mem-type that is used for the allocation, GF_FREE can be
+ * called, or something more intelligent for the structure can be done.
+ */
+int
+gf_get_mem_type (void *ptr)
+{
+        struct mem_acct   *mem_acct;
+        struct mem_header *header = NULL;
+
+        if (!ptr || !THIS->ctx->mem_acct_enable)
+                return 0;
+
+        header = (struct mem_header *) (ptr - GF_MEM_HEADER_SIZE);
+
+        /* Possible corruption, assert here */
+        GF_ASSERT (GF_MEM_HEADER_MAGIC == header->magic);
+
+        return header->type;
+}
+
+
 
 struct mem_pool *
 mem_pool_new_fn (unsigned long sizeof_type,