gfapi: redesign the public interface for upcall consumers

The glfs_callback_arg and glfs_callback_inode_arg were allocated by
gfapi, and expected to be free()'d by the application. However it is not
reasonable to expect that applications use the same memory allocator to
as the compiled libgfapi.so. For instance, it is possible that gfapi
uses glibc malloc/free, and an application like NFS-Ganesha the versions
from jemalloc. Mismatching of the malloc() and free() functions causes
segmentation faults at best.

In order to prevent problems like this in the future, the API for
applications that consume upcalls has been remodeled. Any of the
structures that gfapi allocates, should be free'd with glfs_free(). The
members of the structures can not be accessed directly anymore, each
has its own function to access now.

Correcting the naming of the functions, structures and constants is a
continuation of commit 2775dc64101ed37c8d9809bf9852dbf0746ee2b6. These
new improvements not only have correct prefixes for the functions and
structures, the naming also reflects more to the upcall framework and
does not use "callback" anymore.

Cherry picked from commit 4721188a154acd9a0a4c096d8d73e97f3bf1b2a9:
> Change-Id: I2b8bd5a0a82036d2abea1a217f5e5975a1d4fe93
> BUG: 1344714
> Signed-off-by: Niels de Vos <ndevos@redhat.com>
> Reviewed-on: http://review.gluster.org/14701
> Smoke: Gluster Build System <jenkins@build.gluster.org>
> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
> Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
> Reviewed-by: soumya k <skoduri@redhat.com>
> Reviewed-by: jiffin tony Thottan <jthottan@redhat.com>

Once difference with the version of this change in other branches is
that leases are not included in glusterfs-3.7. Hence there is a little
change that drops the handling of GF_UPCALL_RECALL_LEASE.

In addition, this backport contains commit 2775dc6410:
> libgfapi/upcall : prepend "glfs_" to callback_arg, callback_inode_arg
> Reviewed-on: http://review.gluster.org/14702

Change-Id: I2b8bd5a0a82036d2abea1a217f5e5975a1d4fe93
BUG: 1347715
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/15602
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Kaushal M <kaushal@redhat.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/api/src/glfs.c b/api/src/glfs.c
index 1fc1a30ac4c..096e6aec2cf 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -1281,3 +1281,107 @@ invalid_fs:
 }
 
 GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_ipc, 3.7.0);
+
+
+void
+pub_glfs_free (void *ptr)
+{
+        int mem_type = 0;
+
+        mem_type = gf_get_mem_type (ptr);
+
+        switch (mem_type) {
+        case glfs_mt_upcall_entry_t:
+        {
+                struct glfs_upcall *to_free = ptr;
+
+                if (to_free->event)
+                        to_free->free_event (to_free->event);
+
+                GF_FREE (ptr);
+                break;
+        }
+        default:
+                GF_FREE (ptr);
+        }
+}
+
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_free, 3.7.16);
+
+
+struct glfs*
+pub_glfs_upcall_get_fs (struct glfs_upcall *arg)
+{
+        return arg->fs;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_fs, 3.7.16);
+
+enum glfs_upcall_reason
+pub_glfs_upcall_get_reason (struct glfs_upcall *arg)
+{
+        return arg->reason;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_reason, 3.7.16);
+
+void*
+pub_glfs_upcall_get_event (struct glfs_upcall *arg)
+{
+        return arg->event;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_event, 3.7.16);
+
+struct glfs_object*
+pub_glfs_upcall_inode_get_object (struct glfs_upcall_inode *arg)
+{
+        return arg->object;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_object, 3.7.16);
+
+uint64_t
+pub_glfs_upcall_inode_get_flags (struct glfs_upcall_inode *arg)
+{
+        return arg->flags;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_flags, 3.7.16);
+
+struct stat*
+pub_glfs_upcall_inode_get_stat (struct glfs_upcall_inode *arg)
+{
+        return &arg->buf;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_stat, 3.7.16);
+
+uint64_t
+pub_glfs_upcall_inode_get_expire (struct glfs_upcall_inode *arg)
+{
+        return arg->expire_time_attr;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_expire, 3.7.16);
+
+struct glfs_object*
+pub_glfs_upcall_inode_get_pobject (struct glfs_upcall_inode *arg)
+{
+        return arg->p_object;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_pobject, 3.7.16);
+
+struct stat*
+pub_glfs_upcall_inode_get_pstat (struct glfs_upcall_inode *arg)
+{
+        return &arg->p_buf;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_pstat, 3.7.16);
+
+struct glfs_object*
+pub_glfs_upcall_inode_get_oldpobject (struct glfs_upcall_inode *arg)
+{
+        return arg->oldp_object;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_oldpobject, 3.7.16);
+
+struct stat*
+pub_glfs_upcall_inode_get_oldpstat (struct glfs_upcall_inode *arg)
+{
+        return &arg->oldp_buf;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_get_oldpstat, 3.7.16);