initial code repo

[stor4nfv.git] / src / ceph / src / os / fs / FS.cc

diff --git a/src/ceph/src/os/fs/FS.cc b/src/ceph/src/os/fs/FS.cc
new file mode 100644 (file)
index 0000000..d15a6bf
--- /dev/null
+++ b/src/ceph/src/os/fs/FS.cc
@@ -0,0 +1,187 @@
+// -*- 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/stat.h>
+#include <fcntl.h>
+
+// from include/linux/falloc.h:
+#ifndef FALLOC_FL_PUNCH_HOLE
+# define FALLOC_FL_PUNCH_HOLE 0x2
+#endif
+
+#include "FS.h"
+
+#include "acconfig.h"
+
+#ifdef HAVE_LIBXFS
+#include "XFS.h"
+#endif
+
+#if defined(DARWIN) || defined(__FreeBSD__)
+#include <sys/mount.h>
+#else
+#include <sys/vfs.h>
+#endif
+#include "include/compat.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, int flags)
+{
+  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");
+}
+
+int FS::zero(int fd, uint64_t offset, uint64_t length)
+{
+  int r;
+
+  /*
+
+    From the fallocate(2) man page:
+
+       Specifying the FALLOC_FL_PUNCH_HOLE flag (available since Linux 2.6.38)
+       in mode deallocates space (i.e., creates a  hole)  in  the  byte  range
+       starting  at offset and continuing for len bytes.  Within the specified
+       range, partial filesystem  blocks  are  zeroed,  and  whole  filesystem
+       blocks  are removed from the file.  After a successful call, subsequent
+       reads from this range will return zeroes.
+
+       The FALLOC_FL_PUNCH_HOLE flag must be ORed with FALLOC_FL_KEEP_SIZE  in
+       mode;  in  other words, even when punching off the end of the file, the
+       file size (as reported by stat(2)) does not change.
+
+       Not all  filesystems  support  FALLOC_FL_PUNCH_HOLE;  if  a  filesystem
+       doesn't  support the operation, an error is returned.  The operation is
+       supported on at least the following filesystems:
+
+       *  XFS (since Linux 2.6.38)
+
+       *  ext4 (since Linux 3.0)
+
+       *  Btrfs (since Linux 3.7)
+
+       *  tmpfs (since Linux 3.5)
+
+   So: we only do this is PUNCH_HOLE *and* KEEP_SIZE are defined.
+
+  */
+#if !defined(DARWIN) && !defined(__FreeBSD__)
+# ifdef CEPH_HAVE_FALLOCATE
+#  ifdef FALLOC_FL_KEEP_SIZE
+  // first try fallocate
+  r = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, offset, length);
+  if (r < 0) {
+    r = -errno;
+  }
+  if (r != -EOPNOTSUPP) {
+    goto out;  // a real error
+  }
+  // if that failed (-EOPNOTSUPP), fall back to writing zeros.
+#  endif
+# endif
+#endif
+
+  {
+    // fall back to writing zeros
+    bufferlist bl;
+    bl.append_zero(length);
+    r = ::lseek64(fd, offset, SEEK_SET);
+    if (r < 0) {
+      r = -errno;
+      goto out;
+    }
+    r = bl.write_fd(fd);
+  }
+
+ out:
+  return r;
+}
+
+// ---------------
+