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: 1501956
Signed-off-by: Soumya Koduri <skoduri@redhat.com>

5 files changed, 87 insertions, 1 deletions

diff --git a/api/src/gfapi.aliases b/api/src/gfapi.aliases
index b0facb717b3..85e8448982d 100644
--- a/api/src/gfapi.aliases
+++ b/api/src/gfapi.aliases
@@ -156,6 +156,7 @@ _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
 
 _pub_glfs_xreaddirplus_r _glfs_xreaddirplus_r$GFAPI_3.11.0
 _pub_glfs_xreaddirplus_r_get_stat _glfs_xreaddirplus_r_get_stat$GFAPI_3.11.0
diff --git a/api/src/gfapi.map b/api/src/gfapi.map
index 7f19e1ee4f9..88673007d25 100644
--- a/api/src/gfapi.map
+++ b/api/src/gfapi.map
@@ -198,12 +198,17 @@ GFAPI_3.10.0 {
 		glfs_sysrq;
 } GFAPI_3.7.17;
 
+GFAPI_3.10.7 {
+	global:
+		glfs_fd_set_lkowner;
+} GFAPI_3.10.0;
+
 GFAPI_3.11.0 {
 		glfs_xreaddirplus_r;
 		glfs_xreaddirplus_r_get_stat;
 		glfs_xreaddirplus_r_get_object;
                 glfs_object_copy;
-} GFAPI_3.10.0;
+} GFAPI_3.10.7;
 
 GFAPI_PRIVATE_3.12.0 {
 	global:
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index c8ddeea196e..7fb86fc859f 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:
@@ -4272,6 +4278,14 @@ 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);
@@ -4294,6 +4308,43 @@ 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 180981830d7..c94fcd9078d 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 5420a1dde66..ec3258d083a 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -855,6 +855,34 @@ glfs_xreaddirplus_r (struct glfs_fd *glfd, uint32_t flags,
                      struct dirent *ext, struct dirent **res);
         GFAPI_PUBLIC(glfs_xreaddirplus_r, 3.11.0);
 
+#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 */