1 files changed, 124 insertions, 0 deletions
diff --git a/xlators/features/metadisp/src/metadisp-stat.c b/xlators/features/metadisp/src/metadisp-stat.c
new file mode 100644
index 00000000000..b06d0dbcddd
--- /dev/null
+++ b/xlators/features/metadisp/src/metadisp-stat.c
@@ -0,0 +1,124 @@
+#include "metadisp.h"
+#include <glusterfs/call-stub.h>
+
+/**
+ * The stat flow in METADISP is complicated because we must
+ * do ensure a few things:
+ *    1. stat, on the path within the metadata layer,
+ *       MUST get the backend FD of the data layer.
+ *        --- we wind to the metadata layer, then the data layer.
+ *
+ *    2. the metadata layer MUST be able to ask the data
+ *       layer for stat information.
+ *        --- this is 'syncop-internal-from-posix'
+ *
+ *    3. when the metadata exists BUT the data is missing,
+ *       we MUST mark the backend file as bad and heal it.
+ */
+
+int32_t
+metadisp_stat_backend_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
+                          int32_t op_ret, int32_t op_errno, struct iatt *buf,
+                          dict_t *xdata)
+{
+    METADISP_TRACE("got backend stat results %d %d", op_ret, op_errno);
+    if (op_errno == ENOENT) {
+        STACK_UNWIND_STRICT(open, frame, -1, ENODATA, NULL, NULL);
+        return 0;
+    }
+    STACK_UNWIND_STRICT(stat, frame, op_ret, op_errno, buf, xdata);
+    return 0;
+}
+
+int32_t
+metadisp_stat_resume(call_frame_t *frame, xlator_t *this, loc_t *loc,
+                     dict_t *xdata)
+{
+    METADISP_TRACE("winding stat to path %s", loc->path);
+    if (gf_uuid_is_null(loc->gfid)) {
+        METADISP_TRACE("bad object, sending EUCLEAN");
+        STACK_UNWIND_STRICT(open, frame, -1, EUCLEAN, NULL, NULL);
+        return 0;
+    }
+
+    STACK_WIND(frame, metadisp_stat_backend_cbk, SECOND_CHILD(this),
+               SECOND_CHILD(this)->fops->stat, loc, xdata);
+    return 0;
+}
+
+int32_t
+metadisp_stat_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
+                  int32_t op_ret, int32_t op_errno, struct iatt *buf,
+                  dict_t *xdata)
+{
+    call_stub_t *stub = NULL;
+
+    METADISP_TRACE("got stat results %d %d", op_ret, op_errno);
+
+    if (cookie) {
+        stub = cookie;
+    }
+
+    if (op_ret != 0) {
+        goto unwind;
+    }
+
+    // only use the stub for the files
+    if (!IA_ISREG(buf->ia_type)) {
+        goto unwind;
+    }
+
+    if (stub->poison) {
+        call_stub_destroy(stub);
+        stub = NULL;
+        return 0;
+    }
+
+    call_resume(stub);
+    return 0;
+
+unwind:
+    if (stub) {
+        call_stub_destroy(stub);
+    }
+    STACK_UNWIND_STRICT(stat, frame, op_ret, op_errno, buf, xdata);
+    return 0;
+}
+
+int32_t
+metadisp_stat(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata)
+{
+    call_stub_t *stub = NULL;
+    int32_t ret = 0;
+    loc_t backend_loc = {
+        0,
+    };
+    METADISP_FILTER_ROOT(stat, loc, xdata);
+
+    if (build_backend_loc(loc->gfid, loc, &backend_loc)) {
+        goto unwind;
+    }
+
+    if (dict_get_int32(xdata, "syncop-internal-from-posix", &ret) == 0) {
+        // if we've just been sent a stat from posix, then we know
+        // that we must send down a stat for a file to the second child.
+        //
+        // that means we can skip the stat for the first child and just
+        // send to the data disk.
+        METADISP_TRACE("got syncop-internal-from-posix");
+        STACK_WIND(frame, default_stat_cbk, DATA_CHILD(this),
+                   DATA_CHILD(this)->fops->stat, &backend_loc, xdata);
+        return 0;
+    }
+
+    // we do not know if the request is for a file, folder, etc. wind
+    // to first child to find out.
+    stub = fop_stat_stub(frame, metadisp_stat_resume, &backend_loc, xdata);
+    METADISP_TRACE("winding stat to first child %s", loc->path);
+    STACK_WIND_COOKIE(frame, metadisp_stat_cbk, stub, METADATA_CHILD(this),
+                      METADATA_CHILD(this)->fops->stat, loc, xdata);
+    return 0;
+unwind:
+    STACK_UNWIND_STRICT(stat, frame, -1, EINVAL, NULL, NULL);
+    return 0;
+}