gfapi: Bug fixes in leases processing code-path

This patch fixes below issues in gfapi lease code-path
* 'glfs_setfsleasid' should allow NULL input to be
   able to reset leaseid
* Applications should be allowed to (un)register for
  upcall notifications of type GLFS_EVENT_LEASE_RECALL
* APIs added to read contents of GLFS_EVENT_LEASE_RECALL
  argument which is of type "struct glfs_upcall_lease"

This is backport of below mainline path -
https://review.gluster.org/#/c/glusterfs/+/21391

Change-Id: I3320ddf235cc82fad561e13b9457ebd64db6c76b
updates: #350
Signed-off-by: Soumya Koduri <skoduri@redhat.com>

6 files changed, 69 insertions, 29 deletions

diff --git a/api/src/gfapi.aliases b/api/src/gfapi.aliases
index 74053b9af6a..fd4f437ccc3 100644
--- a/api/src/gfapi.aliases
+++ b/api/src/gfapi.aliases
@@ -174,3 +174,5 @@ _pub_glfs_setfsleaseid _glfs_setfsleaseid$GFAPI_4.0.0
 _pub_glfs_file_lock _glfs_file_lock$GFAPI_4.0.0
 _pub_glfs_lease _glfs_lease$GFAPI_4.0.0
 _pub_glfs_h_lease _glfs_h_lease$GFAPI_4.0.0
+_pub_glfs_upcall_lease_get_object _glfs_upcall_lease_get_object$GFAPI_4.1.6
+_pub_glfs_upcall_lease_get_lease_type _glfs_upcall_lease_get_lease_type$GFAPI_4.1.6
diff --git a/api/src/gfapi.map b/api/src/gfapi.map
index 4984479c57a..6dd907d2122 100644
--- a/api/src/gfapi.map
+++ b/api/src/gfapi.map
@@ -228,3 +228,8 @@ GFAPI_4.0.0 {
                 glfs_lease;
                 glfs_h_lease;
 } GFAPI_3.13.0;
+
+GFAPI_4.1.6 {
+                glfs_upcall_lease_get_object;
+                glfs_upcall_lease_get_lease_type;
+} GFAPI_4.0.0;
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index f243999c0c8..50f32fae6f6 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -4841,7 +4841,7 @@ glfs_recall_lease_upcall (struct glfs *fs,
 
         up_lease_arg->lease_type = recall_lease->lease_type;
 
-        up_arg->reason = GF_UPCALL_RECALL_LEASE;
+        up_arg->reason = GLFS_UPCALL_RECALL_LEASE;
         up_arg->event = up_lease_arg;
         up_arg->free_event = glfs_free_upcall_lease;
 
diff --git a/api/src/glfs-handles.h b/api/src/glfs-handles.h
index 58ef85a9f47..6dfb027a9a4 100644
--- a/api/src/glfs-handles.h
+++ b/api/src/glfs-handles.h
@@ -337,6 +337,26 @@ struct glfs_object *
 glfs_h_find_handle (struct glfs *fs, unsigned char *handle,
                     int len) __THROW
         GFAPI_PUBLIC(glfs_h_lease, 4.0.0);
+
+/* Functions for getting details about the glfs_upcall_lease
+ *
+ * None of the pointers returned by the below functions should be free()'d,
+ * glfs_free()'d or glfs_h_close()'d by the application.
+ *
+ * Releasing of the structures is done by passing the glfs_upcall pointer
+ * to glfs_free().
+ */
+struct glfs_upcall_lease;
+typedef struct glfs_upcall_lease glfs_upcall_lease_t;
+
+glfs_object_t *
+glfs_upcall_lease_get_object(glfs_upcall_lease_t *arg) __THROW
+    GFAPI_PUBLIC(glfs_upcall_lease_get_object, 4.1.6);
+
+uint32_t
+glfs_upcall_lease_get_lease_type(glfs_upcall_lease_t *arg) __THROW
+    GFAPI_PUBLIC(glfs_upcall_lease_get_lease_type, 4.1.6);
+
 __END_DECLS
 
 #endif /* !_GLFS_HANDLES_H */
diff --git a/api/src/glfs.c b/api/src/glfs.c
index cc84842f286..508191ec8b1 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -576,14 +576,17 @@ pub_glfs_setfsleaseid (glfs_leaseid_t leaseid)
         int           ret     = -1;
         char         *gleaseid = NULL;
 
-        GF_VALIDATE_OR_GOTO (THIS->name, leaseid, out);
-
         gleaseid = gf_leaseid_get();
         if (gleaseid) {
-                memcpy (gleaseid, leaseid, LEASE_ID_SIZE);
+                if (leaseid)
+                        memcpy(gleaseid, leaseid, LEASE_ID_SIZE);
+                else /* reset leaseid */
+                        memset(gleaseid, 0, LEASE_ID_SIZE);
                 ret = 0;
         }
-out:
+        if (ret)
+                gf_log("glfs", GF_LOG_ERROR, "failed to set leaseid: %s",
+                       strerror(errno));
         return ret;
 }
 
@@ -1566,22 +1569,20 @@ pub_glfs_upcall_inode_get_oldpstat (struct glfs_upcall_inode *arg)
 }
 GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_inode_get_oldpstat, 3.7.16);
 
-
-/*struct glfs_object*
-pub_glfs_upcall_lease_get_object (struct glfs_upcall_recall_inode *arg)
+struct glfs_object *
+pub_glfs_upcall_lease_get_object(struct glfs_upcall_lease *arg)
 {
         return arg->object;
 }
 
-GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_lease_get_object, 4.0.0);
-*/
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_lease_get_object, 4.1.6);
 
 uint32_t
 pub_glfs_upcall_lease_get_lease_type (struct glfs_upcall_lease *arg)
 {
         return arg->lease_type;
 }
-GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_lease_get_lease_type, 4.0.0);
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_upcall_lease_get_lease_type, 4.1.6);
 
 /* definitions of the GLFS_SYSRQ_* chars are in glfs.h */
 static struct glfs_sysrq_help {
@@ -1647,7 +1648,8 @@ pub_glfs_upcall_register (struct glfs *fs, uint32_t event_list,
         int ret = 0;
 
         /* list of supported upcall events */
-        uint32_t up_events = GLFS_EVENT_INODE_INVALIDATE;
+        uint32_t up_events = (GLFS_EVENT_INODE_INVALIDATE |
+                              GLFS_EVENT_RECALL_LEASE);
 
         DECLARE_OLD_THIS;
         __GLFS_ENTRY_VALIDATE_FS (fs, invalid_fs);
@@ -1666,18 +1668,20 @@ pub_glfs_upcall_register (struct glfs *fs, uint32_t event_list,
                 goto out;
         }
 
-        /* incase other thread does unregister */
-        pthread_mutex_lock (&fs->mutex);
+        /* in case other thread does unregister */
+        pthread_mutex_lock(&fs->mutex);
         {
                 if (event_list & GLFS_EVENT_INODE_INVALIDATE) {
                         /* @todo: Check if features.cache-invalidation is
                          * enabled.
                          */
-                        fs->upcall_events |=  GF_UPCALL_CACHE_INVALIDATION;
-                        ret |= GF_UPCALL_CACHE_INVALIDATION;
-                } else if (event_list & GLFS_EVENT_INODE_INVALIDATE) {
-                        fs->upcall_events |=  GF_UPCALL_RECALL_LEASE;
-                        ret |= GF_UPCALL_RECALL_LEASE;
+                        fs->upcall_events |= GF_UPCALL_CACHE_INVALIDATION;
+                        ret |= GLFS_EVENT_INODE_INVALIDATE;
+                }
+                if (event_list & GLFS_EVENT_RECALL_LEASE) {
+                        /* @todo: Check if features.leases is enabled */
+                        fs->upcall_events |= GF_UPCALL_RECALL_LEASE;
+                        ret |= GLFS_EVENT_RECALL_LEASE;
                 }
                 /* Override cbk function if existing */
                 fs->up_cbk = cbk;
@@ -1700,7 +1704,8 @@ pub_glfs_upcall_unregister (struct glfs *fs, uint32_t event_list)
 {
         int ret = 0;
         /* list of supported upcall events */
-        uint32_t up_events = GLFS_EVENT_INODE_INVALIDATE;
+        uint32_t up_events = (GLFS_EVENT_INODE_INVALIDATE |
+                              GLFS_EVENT_RECALL_LEASE);
 
         DECLARE_OLD_THIS;
         __GLFS_ENTRY_VALIDATE_FS (fs, invalid_fs);
@@ -1719,10 +1724,12 @@ pub_glfs_upcall_unregister (struct glfs *fs, uint32_t event_list)
 
         pthread_mutex_lock (&fs->mutex);
         {
-                if (event_list & GLFS_EVENT_INODE_INVALIDATE) {
-                        fs->upcall_events &=  ~GF_UPCALL_CACHE_INVALIDATION;
-                        ret |= GF_UPCALL_CACHE_INVALIDATION;
-                }
+                /* We already checked if event_list contains list of supported
+                 * upcall events. No other specific checks needed as of now for
+                 * unregister */
+                fs->upcall_events &= ~(event_list);
+                ret |= ((event_list == GLFS_EVENT_ANY) ?
+                         up_events : event_list);
 
                 /* If there are no upcall events registered, reset cbk */
                 if (fs->upcall_events == 0) {
diff --git a/api/src/glfs.h b/api/src/glfs.h
index 16eae642906..dd6142757d6 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -960,7 +960,8 @@ glfs_upcall_get_fs (struct glfs_upcall *arg) __THROW
 
 enum glfs_upcall_reason {
         GLFS_UPCALL_EVENT_NULL = 0,
-        GLFS_UPCALL_INODE_INVALIDATE,    /* invalidate cache entry */
+        GLFS_UPCALL_INODE_INVALIDATE, /* invalidate cache entry */
+        GLFS_UPCALL_RECALL_LEASE,     /* recall lease */
 };
 
 enum glfs_upcall_reason
@@ -980,6 +981,7 @@ glfs_upcall_get_reason (struct glfs_upcall *arg) __THROW
  *      ==========================================================
  *      GLFS_UPCALL_EVENT_NULL       -    NULL
  *      GLFS_UPCALL_INODE_INVALIDATE -    struct glfs_upcall_inode
+ *      GLFS_UPCALL_RECALL_LEASE     -    struct glfs_upcall_lease
  *
  * After processing upcall event, glfs_free() should be called on the
  * glfs_upcall.
@@ -1012,8 +1014,9 @@ typedef void (*glfs_upcall_cbk) (struct glfs_upcall *up_arg, void *data);
 /*
  * List of upcall events supported by gluster/gfapi
  */
-#define GLFS_EVENT_INODE_INVALIDATE    0x00000001 /* invalidate cache entry */
-#define GLFS_EVENT_ANY                 0xffffffff /* for all the above events */
+#define GLFS_EVENT_INODE_INVALIDATE 0x00000001 /* invalidate cache entry */
+#define GLFS_EVENT_RECALL_LEASE 0x00000002     /* Recall lease */
+#define GLFS_EVENT_ANY 0xffffffff              /* for all the above events */
 
 /*
  * SYNOPSIS
@@ -1037,7 +1040,8 @@ typedef void (*glfs_upcall_cbk) (struct glfs_upcall *up_arg, void *data);
  *
  * @event_list: List of upcall events to be registered.
  *              Current available values are:
- *               - GFAPI_UPCALL_INODE_INVALIDATE
+ *               - GLFS_EVENT_INODE_INVALIDATE
+ *               - GLFS_EVENT_RECALL_LEASE
  *
  * @cbk: The cbk routine to be invoked incase of any upcall received
  * @data: Any opaque pointer provided by caller which shall be using while
@@ -1071,7 +1075,8 @@ glfs_upcall_register (struct glfs *fs, uint32_t event_list,
  *
  * @event_list: List of upcall events to be unregistered.
  *              Current available values are:
- *               - GFAPI_UPCALL_INODE_INVALIDATE
+ *               - GLFS_EVENT_INODE_INVALIDATE
+ *               - GLFS_EVENT_RECALL_LEASE
  * RETURN VALUE:
  * >0: SUCCESS (value contains the events successfully unregistered)
  * -1: FAILURE
@@ -1082,6 +1087,7 @@ glfs_upcall_unregister (struct glfs *fs, uint32_t event_list) __THROW
 
 /* Lease Types */
 enum glfs_lease_types {
+        GLFS_LEASE_NONE = 0,
         GLFS_RD_LEASE = 1,
         GLFS_RW_LEASE = 2,
 };