From: Matt Benjamin <mbenjamin@redhat.com>
Date: Tue, 11 Jul 2017 23:30:12 +0000 (-0400)
Subject: rgw_file: permit dirent offset computation
X-Git-Tag: v12.1.2~225^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e121fd04d652d4b6949c96b93a24b1032a1e9575;p=ceph.git

rgw_file: permit dirent offset computation

The new dirent chunking feature in nfs-ganesha 2.5 includes an
optimization inspired by RGW NFS, and avoids invalidating modified
dirs when the underlying FSAL can project the offset of a
name in it's parent directory, independent of other entries (e.g.,
if offset is a stable hash).

Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>
---

diff --git a/src/include/rados/rgw_file.h b/src/include/rados/rgw_file.h
index add86df471de..95ca603c9653 100644
--- a/src/include/rados/rgw_file.h
+++ b/src/include/rados/rgw_file.h
@@ -27,7 +27,7 @@ extern "C" {
 
 #define LIBRGW_FILE_VER_MAJOR 1
 #define LIBRGW_FILE_VER_MINOR 1
-#define LIBRGW_FILE_VER_EXTRA 3
+#define LIBRGW_FILE_VER_EXTRA 4
 
 #define LIBRGW_FILE_VERSION(maj, min, extra) ((maj << 16) + (min << 8) + extra)
 #define LIBRGW_FILE_VERSION_CODE LIBRGW_FILE_VERSION(LIBRGW_FILE_VER_MAJOR, LIBRGW_FILE_VER_MINOR, LIBRGW_FILE_VER_EXTRA)
@@ -217,6 +217,14 @@ int rgw_readdir(struct rgw_fs *rgw_fs,
 		rgw_readdir_cb rcb, void *cb_arg, bool *eof,
 		uint32_t flags);
 
+/* project offset of dirent name */
+#define RGW_DIRENT_OFFSET_FLAG_NONE 0x0000
+
+int rgw_dirent_offset(struct rgw_fs *rgw_fs,
+		      struct rgw_file_handle *parent_fh,
+		      const char *name, int64_t *offset,
+		      uint32_t flags);
+
 /*
    get unix attributes for object
 */
diff --git a/src/rgw/rgw_file.cc b/src/rgw/rgw_file.cc
index ca8a5c4b4b87..344c29bb4196 100644
--- a/src/rgw/rgw_file.cc
+++ b/src/rgw/rgw_file.cc
@@ -1796,6 +1796,22 @@ int rgw_readdir(struct rgw_fs *rgw_fs,
   return rc;
 }
 
+/* project offset of dirent name */
+int rgw_dirent_offset(struct rgw_fs *rgw_fs,
+		      struct rgw_file_handle *parent_fh,
+		      const char *name, int64_t *offset,
+		      uint32_t flags)
+{
+  RGWFileHandle* parent = get_rgwfh(parent_fh);
+  if ((! parent)) {
+    /* bad parent */
+    return -EINVAL;
+  }
+  std::string sname{name};
+  int rc = parent->offset_of(sname, offset, flags);
+  return rc;
+}
+
 /*
    read data from file
 */
diff --git a/src/rgw/rgw_file.h b/src/rgw/rgw_file.h
index b93b59284093..374e55200a11 100644
--- a/src/rgw/rgw_file.h
+++ b/src/rgw/rgw_file.h
@@ -504,6 +504,14 @@ namespace rgw {
       return nullptr;
     }
 
+    int offset_of(const std::string& name, int64_t *offset, uint32_t flags) {
+      if (unlikely(! is_dir())) {
+	return -EINVAL;
+      }
+      *offset = XXH64(name.c_str(), name.length(), fh_key::seed);
+      return 0;
+    }
+
     bool is_open() const { return flags & FLAG_OPEN; }
     bool is_root() const { return flags & FLAG_ROOT; }
     bool is_bucket() const { return flags & FLAG_BUCKET; }