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-rw-r--r--xlators/features/metadisp/src/metadisp-stat.c124
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 0000000..b06d0db
--- /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;
+}