libgfapi : anonymous fd support

      backport of http://review.gluster.org/#/c/9971/

Anonymous fd's are floating fd assigned to a glusterfs client
without a explicit file open. Here either it will create a new
anonymous fd or existing anonymous fd in the client stack for
requested file.The anonymous fd's are mainly used for IO's.
This patch introduces two api's glfs_h_anonymous_read and
glfs_h_anonymous_write which performs read and write respectively

cherry-picked as fa0ad231745846918b2625d0e1a89c0a5c3c24dc
>Change-Id: Id646f2220e8387b2f8bb244c848dc1db6761444f
>BUG: 1204651
>Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
>Reviewed-by: Niels de Vos <ndevos@redhat.com>
>Reviewed-on: http://review.gluster.org/9971
>Tested-by: Gluster Build System <jenkins@build.gluster.com>
>Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>

Change-Id: I6b01d88f92ad045e48debee23aa79f4517c6bdc2
BUG: 1218857
Signed-off-by: Jiffin Tony Thottan <jthottan@redhat.com>
Reviewed-on: http://review.gluster.org/10635
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/api/src/glfs-handleops.c b/api/src/glfs-handleops.c
index 4a544f7c905..2793e1cb118 100644
--- a/api/src/glfs-handleops.c
+++ b/api/src/glfs-handleops.c
@@ -1962,3 +1962,51 @@ pub_glfs_h_acl_set (struct glfs *fs, struct glfs_object *object,
 #endif
 GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_h_acl_set, 3.7.0);
 GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_h_acl_get, 3.7.0);
+
+/* The API to perform read using anonymous fd */
+ssize_t
+pub_glfs_h_anonymous_read (struct glfs *fs, struct glfs_object *object,
+                           const void *buf, size_t count, off_t offset)
+{
+        struct iovec    iov     = {0, };
+        ssize_t         ret     = 0;
+
+        /* validate in args */
+        if ((fs == NULL) || (object == NULL)) {
+                errno = EINVAL;
+                return -1;
+        }
+
+        iov.iov_base = (void *) buf;
+        iov.iov_len = count;
+
+        ret = glfs_anonymous_preadv (fs, object, &iov, 1, offset, 0);
+
+        return ret;
+}
+
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_h_anonymous_read, 3.7.0);
+
+/* The API to perform write using anonymous fd */
+ssize_t
+pub_glfs_h_anonymous_write (struct glfs *fs, struct glfs_object *object,
+                            const void *buf, size_t count, off_t offset)
+{
+        struct iovec iov        = {0, };
+        ssize_t      ret        = 0;
+
+        /* validate in args */
+        if ((fs == NULL) || (object == NULL)) {
+                errno = EINVAL;
+                return -1;
+        }
+
+        iov.iov_base = (void *) buf;
+        iov.iov_len = count;
+
+        ret = glfs_anonymous_pwritev (fs, object, &iov, 1, offset, 0);
+
+        return ret;
+}
+
+GFAPI_SYMVER_PUBLIC_DEFAULT(glfs_h_anonymous_write, 3.7.0);