os/fs: add simple FS abstraction layer

- open by handle
- xfs allocation hint

Signed-off-by: Sage Weil <sage@redhat.com>

configure.ac

@@ -954,6 +954,11 @@ AC_CHECK_HEADERS([ \
 	utime.h \
 ])
 
+# name_to_handle_at
+AC_CHECK_FUNC([name_to_handle_at],
+	[AC_DEFINE([HAVE_NAME_TO_HANDLE_AT], [], [name_to_handle_at exists])],
+	[])
+
 # sync_file_range
 AC_CHECK_FUNC([sync_file_range],
 	[AC_DEFINE([HAVE_SYNC_FILE_RANGE], [], [sync_file_range(2) is supported])],

src/os/Makefile.am

@@ -7,6 +7,8 @@ if ENABLE_SERVER
 
 libos_la_SOURCES = \
 	os/chain_xattr.cc \
+	os/fs/FS.cc \
+	os/fs/XFS.cc \
 	os/DBObjectMap.cc \
 	os/GenericObjectMap.cc \
 	os/FileJournal.cc \
@@ -54,6 +56,8 @@ noinst_HEADERS += \
 	os/FileJournal.h \
 	os/FileStore.h \
 	os/FDCache.h \
+	os/fs/FS.h \
+	os/fs/XFS.h \
 	os/GenericFileStoreBackend.h \
 	os/HashIndex.h \
 	os/IndexManager.h \

src/os/fs/FS.cc

@@ -0,0 +1,105 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/vfs.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "FS.h"
+
+#include "XFS.h"
+
+#include "acconfig.h"
+
+// ---------------
+
+FS *FS::create(uint64_t f_type)
+{
+  switch (f_type) {
+#ifdef HAVE_LIBXFS
+  case XFS_SUPER_MAGIC:
+    return new XFS;
+#endif
+  default:
+    return new FS;
+  }
+}
+
+FS *FS::create_by_fd(int fd)
+{
+  struct statfs st;
+  ::fstatfs(fd, &st);
+  return create(st.f_type);
+}
+
+// ---------------
+
+int FS::set_alloc_hint(int fd, uint64_t hint)
+{
+  return 0;  // no-op
+}
+
+#ifdef HAVE_NAME_TO_HANDLE_AT
+int FS::get_handle(int fd, std::string *h)
+{
+  char buf[sizeof(struct file_handle) + MAX_HANDLE_SZ];
+  struct file_handle *fh = (struct file_handle *)buf;
+  int mount_id;
+
+  fh->handle_bytes = MAX_HANDLE_SZ;
+  int r = name_to_handle_at(fd, "", fh, &mount_id, AT_EMPTY_PATH);
+  if (r < 0) {
+    return -errno;
+  }
+  *h = std::string(buf, fh->handle_bytes + sizeof(struct file_handle));
+  return 0;
+}
+
+int FS::open_handle(int mount_fd, const std::string& h, int flags)
+{
+  if (h.length() < sizeof(struct file_handle)) {
+    return -EINVAL;
+  }
+  struct file_handle *fh = (struct file_handle *)h.data();
+  if (fh->handle_bytes > h.length()) {
+    return -ERANGE;
+  }
+  int fd = open_by_handle_at(mount_fd, fh, flags);
+  if (fd < 0)
+    return -errno;
+  return fd;
+}
+
+#else // HAVE_NAME_TO_HANDLE_AT
+
+int FS::get_handle(int fd, std::string *h)
+{
+  return -EOPNOTSUPP;
+}
+
+int FS::open_handle(int mount_fd, const std::string& h)
+{
+  return -EOPNOTSUPP;
+}
+
+#endif // HAVE_NAME_TO_HANDLE_AT
+
+int FS::copy_file_range(int to_fd, uint64_t to_offset,
+			int from_fd,
+			uint64_t from_offset, uint64_t from_len)
+{
+  assert(0 == "write me");
+}

src/os/fs/FS.h

@@ -0,0 +1,43 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_OS_FS_H
+#define CEPH_OS_FS_H
+
+#include <string>
+
+#include "include/types.h"
+
+class FS {
+public:
+  virtual ~FS() { }
+
+  static FS *create(uint64_t f_type);
+  static FS *create_by_fd(int fd);
+
+  virtual const char *get_name() {
+    return "generic";
+  }
+
+  virtual int set_alloc_hint(int fd, uint64_t hint);
+
+  virtual int get_handle(int fd, std::string *h);
+  virtual int open_handle(int mount_fd, const std::string& h, int flags);
+
+  virtual int copy_file_range(int to_fd, uint64_t to_offset,
+			      int from_fd,
+			      uint64_t from_offset, uint64_t from_len);
+};
+
+#endif

src/os/fs/XFS.cc

@@ -0,0 +1,55 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#include "XFS.h"
+
+#include <xfs/xfs.h>
+
+int XFS::set_alloc_hint(int fd, uint64_t val)
+{
+  struct fsxattr fsx;
+  struct stat sb;
+  int ret;
+
+  if (fstat(fd, &sb) < 0) {
+    ret = -errno;
+    return ret;
+  }
+  if (!S_ISREG(sb.st_mode)) {
+    return -EINVAL;
+  }
+
+  if (ioctl(fd, XFS_IOC_FSGETXATTR, &fsx) < 0) {
+    ret = -errno;
+    return ret;
+  }
+
+  // already set?
+  if ((fsx.fsx_xflags & XFS_XFLAG_EXTSIZE) && fsx.fsx_extsize == val)
+    return 0;
+
+  // xfs won't change extent size if any extents are allocated
+  if (fsx.fsx_nextents != 0)
+    return 0;
+
+  fsx.fsx_xflags |= XFS_XFLAG_EXTSIZE;
+  fsx.fsx_extsize = val;
+
+  if (ioctl(fd, XFS_IOC_FSSETXATTR, &fsx) < 0) {
+    ret = -errno;
+    return ret;
+  }
+
+  return 0;
+}

src/os/fs/XFS.h

@@ -0,0 +1,31 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Red Hat
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_OS_XFS_H
+#define CEPH_OS_XFS_H
+
+#include "FS.h"
+
+# ifndef XFS_SUPER_MAGIC
+static const __SWORD_TYPE XFS_SUPER_MAGIC(0x58465342);
+# endif
+
+class XFS : public FS {
+  const char *get_name() {
+    return "xfs";
+  }
+  int set_alloc_hint(int fd, uint64_t hint);
+};
+
+#endif