1 files changed, 182 insertions, 0 deletions
diff --git a/src/os/filestore/chain_xattr.h b/src/os/filestore/chain_xattr.h
new file mode 100644
index 000000000..25f75cfaa
--- /dev/null
+++ b/src/os/filestore/chain_xattr.h
@@ -0,0 +1,182 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef __CEPH_OSD_CHAIN_XATTR_H
+#define __CEPH_OSD_CHAIN_XATTR_H
+
+#include "include/compat.h"
+#include <errno.h>
+#include <stdio.h>
+#include "os_xattr.h"
+#include "include/ceph_assert.h"
+#include "include/buffer_fwd.h"
+
+#if defined(__linux__)
+#include <linux/limits.h>
+#define CHAIN_XATTR_MAX_NAME_LEN ((XATTR_NAME_MAX + 1) / 2)
+#elif defined(__APPLE__)
+#include <sys/xattr.h>
+#define CHAIN_XATTR_MAX_NAME_LEN ((XATTR_MAXNAMELEN + 1) / 2)
+#else
+#define CHAIN_XATTR_MAX_NAME_LEN  128
+#endif
+
+#define CHAIN_XATTR_MAX_BLOCK_LEN 2048
+
+/*
+ * XFS will only inline xattrs < 255 bytes, so for xattrs that are
+ * likely to fit in the inode, stripe over short xattrs.
+ */
+#define CHAIN_XATTR_SHORT_BLOCK_LEN 250
+#define CHAIN_XATTR_SHORT_LEN_THRESHOLD 1000
+
+// wrappers to hide annoying errno handling.
+
+inline int sys_fgetxattr(int fd, const char *name, void *val, size_t size)
+{
+  int r = ::ceph_os_fgetxattr(fd, name, val, size);
+  return (r < 0 ? -errno : r);
+}
+inline int sys_getxattr(const char *fn, const char *name, void *val, size_t size)
+{
+  int r = ::ceph_os_getxattr(fn, name, val, size);
+  return (r < 0 ? -errno : r);
+}
+
+inline int sys_setxattr(const char *fn, const char *name, const void *val, size_t size)
+{
+  int r = ::ceph_os_setxattr(fn, name, val, size);
+  return (r < 0 ? -errno : r);
+}
+inline int sys_fsetxattr(int fd, const char *name, const void *val, size_t size)
+{
+  int r = ::ceph_os_fsetxattr(fd, name, val, size);
+  return (r < 0 ? -errno : r);
+}
+
+inline int sys_listxattr(const char *fn, char *names, size_t len)
+{
+  int r = ::ceph_os_listxattr(fn, names, len);
+  return (r < 0 ? -errno : r);
+}
+inline int sys_flistxattr(int fd, char *names, size_t len)
+{
+  int r = ::ceph_os_flistxattr(fd, names, len);
+  return (r < 0 ? -errno : r);
+}
+
+inline int sys_removexattr(const char *fn, const char *name)
+{
+  int r = ::ceph_os_removexattr(fn, name);
+  return (r < 0 ? -errno : r);
+}
+inline int sys_fremovexattr(int fd, const char *name)
+{
+  int r = ::ceph_os_fremovexattr(fd, name);
+  return (r < 0 ? -errno : r);
+}
+
+
+// wrappers to chain large values across multiple xattrs
+
+int chain_getxattr(const char *fn, const char *name, void *val, size_t size);
+int chain_getxattr_buf(const char *fn, const char *name, ceph::buffer::ptr *bp);
+int chain_fgetxattr(int fd, const char *name, void *val, size_t size);
+
+int get_xattr_block_size(size_t size);
+void get_raw_xattr_name(const char *name, int i, char *raw_name, int raw_len);
+
+template <bool skip_chain_cleanup=false, bool ensure_single_attr=false>
+int chain_setxattr(
+  const char *fn, const char *name, const void *val, size_t size)
+{
+  int i = 0, pos = 0;
+  char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
+  int ret = 0;
+  size_t max_chunk_size =
+    ensure_single_attr ? size : get_xattr_block_size(size);
+
+  static_assert(
+    !skip_chain_cleanup || ensure_single_attr,
+    "skip_chain_cleanup must imply ensure_single_attr");
+
+  do {
+    size_t chunk_size = (size < max_chunk_size ? size : max_chunk_size);
+    get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
+    size -= chunk_size;
+
+    int r = sys_setxattr(fn, raw_name, (char *)val + pos, chunk_size);
+    if (r < 0) {
+      ret = r;
+      break;
+    }
+    pos  += chunk_size;
+    ret = pos;
+    i++;
+    ceph_assert(size == 0 || !ensure_single_attr);
+  } while (size);
+
+  if (ret >= 0 && !skip_chain_cleanup) {
+    int r;
+    do {
+      get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
+      r = sys_removexattr(fn, raw_name);
+      if (r < 0 && r != -ENODATA)
+	ret = r;
+      i++;
+    } while (r != -ENODATA);
+  }
+
+  return ret;
+}
+
+template <bool skip_chain_cleanup=false, bool ensure_single_attr=false>
+int chain_fsetxattr(
+  int fd, const char *name, const void *val, size_t size)
+{
+  int i = 0, pos = 0;
+  char raw_name[CHAIN_XATTR_MAX_NAME_LEN * 2 + 16];
+  int ret = 0;
+  size_t max_chunk_size =
+    ensure_single_attr ? size : get_xattr_block_size(size);
+
+  static_assert(
+    !skip_chain_cleanup || ensure_single_attr,
+    "skip_chain_cleanup must imply ensure_single_attr");
+
+  do {
+    size_t chunk_size = (size < max_chunk_size ? size : max_chunk_size);
+    get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
+    size -= chunk_size;
+
+    int r = sys_fsetxattr(fd, raw_name, (char *)val + pos, chunk_size);
+    if (r < 0) {
+      ret = r;
+      break;
+    }
+    pos  += chunk_size;
+    ret = pos;
+    i++;
+    ceph_assert(size == 0 || !ensure_single_attr);
+  } while (size);
+
+  if (ret >= 0 && !skip_chain_cleanup) {
+    int r;
+    do {
+      get_raw_xattr_name(name, i, raw_name, sizeof(raw_name));
+      r = sys_fremovexattr(fd, raw_name);
+      if (r < 0 && r != -ENODATA)
+	ret = r;
+      i++;
+    } while (r != -ENODATA);
+  }
+
+  return ret;
+}
+
+int chain_listxattr(const char *fn, char *names, size_t len);
+int chain_flistxattr(int fd, char *names, size_t len);
+int chain_removexattr(const char *fn, const char *name);
+int chain_fremovexattr(int fd, const char *name);
+
+#endif