gfapi: set lkowner in glfd

We need a provision to be able to set lkowner (which is
used to distinguish locks maintained by server) in gfapi.
Since the same lk_owner need to be used to be able to
flush the lock while closing the fd, store the lkowner
in the glfd structure itself.

A new API has been added to be able to set lkowner in glfd.

This is backport of below mainline fix -
 https://review.gluster.org/#/c/18429
 https://review.gluster.org/#/c/18522/

Change-Id: I67591d6b9a89c20b9617d52616513ff9e6c06b47
BUG: 1501955
Signed-off-by: Soumya Koduri <skoduri@redhat.com>

5 files changed, 86 insertions, 0 deletions

diff --git a/api/src/gfapi.aliases b/api/src/gfapi.aliases
index d1bf2b22faa..8be7aa33943 100644
--- a/api/src/gfapi.aliases
+++ b/api/src/gfapi.aliases
@@ -157,3 +157,4 @@ _pub_glfs_upcall_inode_get_oldpstat _glfs_upcall_inode_get_oldpstat$GFAPI_3.7.16
 _pub_glfs_realpath _glfs_realpath$GFAPI_3.7.17
 
 _pub_glfs_sysrq _glfs_sysrq$GFAPI_3.10.0
+_pub_glfs_fd_set_lkowner _glfs_fd_set_lkowner$GFAPI_3.10.7
diff --git a/api/src/gfapi.map b/api/src/gfapi.map
index 48a6d90e922..9e6a0e3d9b3 100644
--- a/api/src/gfapi.map
+++ b/api/src/gfapi.map
@@ -198,3 +198,8 @@ GFAPI_3.10.0 {
 	global:
 		glfs_sysrq;
 } GFAPI_3.7.17;
+
+GFAPI_3.10.7 {
+	global:
+		glfs_fd_set_lkowner;
+} GFAPI_3.10.0;
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index a56c000f724..b721b96885a 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -267,6 +267,12 @@ pub_glfs_close (struct glfs_fd *glfd)
 		goto out;
 	}
 
+        if (glfd->lk_owner.len != 0) {
+                ret = syncopctx_setfslkowner (&glfd->lk_owner);
+                if (ret)
+                        goto out;
+        }
+
 	ret = syncop_flush (subvol, fd, NULL, NULL);
         DECODE_SYNCOP_ERR (ret);
 out:
@@ -4263,6 +4269,14 @@ pub_glfs_posix_lock (struct glfs_fd *glfd, int cmd, struct flock *flock)
 
 	gf_flock_from_flock (&gf_flock, flock);
 	gf_flock_from_flock (&saved_flock, flock);
+
+        if (glfd->lk_owner.len != 0) {
+                ret = syncopctx_setfslkowner (&glfd->lk_owner);
+
+                if (ret)
+                        goto out;
+        }
+
 	ret = syncop_lk (subvol, fd, cmd, &gf_flock, NULL, NULL);
         DECODE_SYNCOP_ERR (ret);
 	gf_flock_to_flock (&gf_flock, flock);
@@ -4285,6 +4299,43 @@ invalid_fs:
 
 GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_posix_lock, 3.4.0);
 
+int
+pub_glfs_fd_set_lkowner (glfs_fd_t *glfd, void *data, int len)
+{
+        int ret = -1;
+
+        DECLARE_OLD_THIS;
+        __GLFS_ENTRY_VALIDATE_FD (glfd, invalid_fs);
+
+        if (!GF_REF_GET (glfd)) {
+                goto invalid_fs;
+        }
+
+        GF_VALIDATE_OR_GOTO (THIS->name, data, out);
+
+        if ((len <= 0) || (len > GFAPI_MAX_LOCK_OWNER_LEN)) {
+                errno = EINVAL;
+                gf_msg (THIS->name, GF_LOG_ERROR, errno,
+                        LG_MSG_INVALID_ARG,
+                        "Invalid lk_owner len (%d)", len);
+                goto out;
+        }
+
+        glfd->lk_owner.len = len;
+
+        memcpy (glfd->lk_owner.data, data, len);
+
+        ret = 0;
+out:
+        if (glfd)
+                GF_REF_PUT (glfd);
+
+        __GLFS_EXIT_FS;
+
+invalid_fs:
+        return ret;
+}
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_fd_set_lkowner, 3.10.7);
 
 struct glfs_fd *
 pub_glfs_dup (struct glfs_fd *glfd)
diff --git a/api/src/glfs-internal.h b/api/src/glfs-internal.h
index a42822420ea..f0a0eadaafa 100644
--- a/api/src/glfs-internal.h
+++ b/api/src/glfs-internal.h
@@ -215,6 +215,7 @@ struct glfs_fd {
 	struct list_head   entries;
 	gf_dirent_t       *next;
 	struct dirent     *readdirbuf;
+        gf_lkowner_t       lk_owner;
 };
 
 /* glfs object handle introduced for the alternate gfapi implementation based
diff --git a/api/src/glfs.h b/api/src/glfs.h
index 397bb878434..a5f6e460934 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -795,6 +795,34 @@ int glfs_sysrq (glfs_t *fs, char sysrq) __THROW
 int glfs_ipc (glfs_fd_t *fd, int cmd) __THROW
         GFAPI_PUBLIC(glfs_ipc, 3.7.0);
 
+#define GFAPI_MAX_LOCK_OWNER_LEN 255
+
+/*
+ *
+ * DESCRIPTION
+ *
+ * This API allows application to set lk_owner on a fd.
+ * A glfd can be associated with only single lk_owner. In case if there
+ * is need to set another lk_owner, applications can make use of
+ * 'glfs_dup' to get duplicate glfd and set new lk_owner on that second
+ * glfd.
+ *
+ * Also its not recommended to override or clear lk_owner value as the
+ * same shall be used to flush any outstanding locks while closing the fd.
+ *
+ * PARAMETERS
+ *
+ * INPUT:
+ * @glfd: GFAPI file descriptor
+ * @len: Size of lk_owner buffer. Max value can be GFAPI_MAX_LOCK_OWNER_LEN
+ * @data: lk_owner data buffer.
+ *
+ * OUTPUT:
+ * 0: SUCCESS
+ * -1: FAILURE
+ */
+int glfs_fd_set_lkowner (glfs_fd_t *glfd, void *data, int len);
+        GFAPI_PUBLIC(glfs_fd_set_lkowner, 3.10.7);
 __END_DECLS
 
 #endif /* !_GLFS_H */