consolidate code for #ifdef HAVE_LINKAT usage

sys_link() now does

ifdef HAVE_LINKAT
        linkat (...)
else
        link (...)
endif

Use sys_link() in all places where we previously had the
conditional behavior.

Change-Id: I8bce5ac1175efd2ba7ab4bb5b372f6d1e0365d28
BUG: 764655
Signed-off-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: http://review.gluster.org/6633
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Xavier Hernandez <xhernandez@datalab.es>
Reviewed-by: Anand Avati <avati@redhat.com>

4 files changed, 20 insertions, 58 deletions

diff --git a/libglusterfs/src/syscall.c b/libglusterfs/src/syscall.c
index 117fa209e21..d1b9ef84c96 100644
--- a/libglusterfs/src/syscall.c
+++ b/libglusterfs/src/syscall.c
@@ -121,7 +121,13 @@ int
 sys_link (const char *oldpath, const char *newpath)
 {
 #ifdef HAVE_LINKAT
-        /* see HAVE_LINKAT in xlators/storage/posix/src/posix.c */
+	/*
+	 * On most systems (Linux being the notable exception), link(2)
+	 * first resolves symlinks. If the target is a directory or
+	 * is nonexistent, it will fail. linkat(2) operates on the
+	 * symlink instead of its target when the AT_SYMLINK_FOLLOW
+	 * flag is not supplied.
+	 */
         return linkat (AT_FDCWD, oldpath, AT_FDCWD, newpath, 0);
 #else
         return link (oldpath, newpath);
diff --git a/xlators/features/index/src/index.c b/xlators/features/index/src/index.c
index 4ba72c02234..db592719b57 100644
--- a/xlators/features/index/src/index.c
+++ b/xlators/features/index/src/index.c
@@ -16,6 +16,7 @@
 #include "options.h"
 #include "glusterfs3-xdr.h"
 #include "syncop.h"
+#include "syscall.h"
 
 #define XATTROP_SUBDIR "xattrop"
 #define BASE_INDICES_HOLDER_SUBDIR "base_indices_holder"
@@ -407,13 +408,8 @@ sync_base_indices (void *index_priv)
                     snprintf (base_index_path, PATH_MAX, "%s/%s",
                               base_indices_holder, entry->d_name);
 
-#ifdef HAVE_LINKAT
-                    /* see HAVE_LINKAT in xlators/storage/posix/src/posix.c */
-                    ret = linkat (AT_FDCWD, xattrop_index_path,
-                                  AT_FDCWD, base_index_path, 0);
-#else
-                    ret = link (xattrop_index_path, base_index_path);
-#endif
+                    ret = sys_link (xattrop_index_path, base_index_path);
+
                     if (ret && errno != EEXIST)
                         goto out;
 
@@ -549,12 +545,8 @@ index_add (xlator_t *this, uuid_t gfid, const char *subdir)
         index_get_index (priv, index);
         make_index_path (priv->index_basepath, subdir,
                          index, index_path, sizeof (index_path));
-#ifdef HAVE_LINKAT
-        /* see HAVE_LINKAT in xlators/storage/posix/src/posix.c */
-        ret = linkat (AT_FDCWD, index_path, AT_FDCWD, gfid_path, 0);
-#else
-        ret = link (index_path, gfid_path);
-#endif
+
+        ret = sys_link (index_path, gfid_path);
         if (!ret || (errno == EEXIST))  {
                 ret = 0;
                 index_created = 1;
@@ -587,12 +579,7 @@ index_add (xlator_t *this, uuid_t gfid, const char *subdir)
         if (fd >= 0)
                 close (fd);
 
-#ifdef HAVE_LINKAT
-        /* see HAVE_LINKAT in xlators/storage/posix/src/posix.c */
-        ret = linkat (AT_FDCWD, index_path, AT_FDCWD, gfid_path, 0);
-#else
-        ret = link (index_path, gfid_path);
-#endif
+        ret = sys_link (index_path, gfid_path);
         if (ret && (errno != EEXIST)) {
                 gf_log (this->name, GF_LOG_ERROR, "%s: Not able to "
                         "add to index (%s)", uuid_utoa (gfid),
@@ -606,12 +593,7 @@ index_add (xlator_t *this, uuid_t gfid, const char *subdir)
                  make_index_path (priv->index_basepath,
                                   GF_BASE_INDICES_HOLDER_GFID,
                                   index, base_path, sizeof (base_path));
-#ifdef HAVE_LINKAT
-                 /* see HAVE_LINKAT in xlators/storage/posix/src/posix.c */
-                 ret = linkat (AT_FDCWD, index_path, AT_FDCWD, base_path, 0);
-#else
-                 ret = link (index_path, base_path);
-#endif
+                 ret = sys_link (index_path, base_path);
                  if (ret)
                          goto out;
         }
diff --git a/xlators/storage/posix/src/posix-handle.c b/xlators/storage/posix/src/posix-handle.c
index 1d8e986314f..613709fc8f1 100644
--- a/xlators/storage/posix/src/posix-handle.c
+++ b/xlators/storage/posix/src/posix-handle.c
@@ -701,16 +701,8 @@ posix_handle_hard (xlator_t *this, const char *oldpath, uuid_t gfid, struct stat
                         return -1;
                 }
 
-#ifdef HAVE_LINKAT
-                /*
-                 * Use linkat if the target may be a symlink to a directory
-                 * or without an existing target. See comment about linkat()
-                 * usage in posix_link() in posix.c for details
-                 */
-                ret = linkat (AT_FDCWD, oldpath, AT_FDCWD, newpath, 0);
-#else
-                ret = link (oldpath, newpath);
-#endif
+                ret = sys_link (oldpath, newpath);
+
                 if (ret) {
                         gf_log (this->name, GF_LOG_WARNING,
                                 "link %s -> %s failed (%s)",
@@ -882,16 +874,7 @@ posix_create_link_if_gfid_exists (xlator_t *this, uuid_t gfid,
         MAKE_HANDLE_PATH (newpath, this, gfid, NULL);
         ret = lstat (newpath, &stbuf);
         if (!ret) {
-#ifdef HAVE_LINKAT
-                /*
-                 * Use linkat if the target may be a symlink to a directory
-                 * or without an existing target. See comment about linkat()
-                 * usage in posix_link() in posix.c for details
-                 */
-                ret = linkat (AT_FDCWD, newpath, AT_FDCWD, real_path, 0);
-#else
-                ret = link (newpath, real_path);
-#endif
+                ret = sys_link (newpath, real_path);
         }
 
         return ret;
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index dc4af1b92f9..83b689d061b 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -1930,18 +1930,9 @@ posix_link (call_frame_t *frame, xlator_t *this,
                 goto out;
         }
 
-#ifdef HAVE_LINKAT
-	/*
-	 * On most systems (Linux being the notable exception), link(2)
-	 * first resolves symlinks. If the target is a directory or
-	 * is nonexistent, it will fail. linkat(2) operates on the
-	 * symlink instead of its target when the AT_SYMLINK_FOLLOW
-	 * flag is not supplied.
-	 */
-        op_ret = linkat (AT_FDCWD, real_oldpath, AT_FDCWD, real_newpath, 0);
-#else
-        op_ret = link (real_oldpath, real_newpath);
-#endif
+
+        op_ret = sys_link (real_oldpath, real_newpath);
+
         if (op_ret == -1) {
                 op_errno = errno;
                 gf_log (this->name, GF_LOG_ERROR,