X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Fkrbd.cc;fp=src%2Fceph%2Fsrc%2Fkrbd.cc;h=4f8b671b429acc35cd0b45df0f10413774b08406;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git

diff --git a/src/ceph/src/krbd.cc b/src/ceph/src/krbd.cc
new file mode 100644
index 0000000..4f8b671
--- /dev/null
+++ b/src/ceph/src/krbd.cc
@@ -0,0 +1,766 @@
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2014 Inktank Storage, Inc.
+ *
+ * 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 <fcntl.h>
+#include <iostream>
+#include <map>
+#include <poll.h>
+#include <sstream>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "auth/KeyRing.h"
+#include "common/errno.h"
+#include "common/Formatter.h"
+#include "common/module.h"
+#include "common/run_cmd.h"
+#include "common/safe_io.h"
+#include "common/secret.h"
+#include "common/TextTable.h"
+#include "include/assert.h"
+#include "include/stringify.h"
+#include "include/krbd.h"
+#include "mon/MonMap.h"
+
+#include <blkid/blkid.h>
+#include <libudev.h>
+
+using namespace std;
+
+const static int POLL_TIMEOUT=120000;
+
+struct krbd_ctx {
+  CephContext *cct;
+  struct udev *udev;
+};
+
+static string get_kernel_rbd_name(const char *id)
+{
+  return string("/dev/rbd") + id;
+}
+
+static int sysfs_write_rbd(const char *which, const string& buf)
+{
+  const string s = string("/sys/bus/rbd/") + which;
+  const string t = s + "_single_major";
+  int fd;
+  int r;
+
+  /*
+   * 'add' and 'add_single_major' interfaces are identical, but if rbd
+   * kernel module is new enough and is configured to use single-major
+   * scheme, 'add' is disabled in order to prevent old userspace from
+   * doing weird things at unmap time.
+   *
+   * Same goes for 'remove' vs 'remove_single_major'.
+   */
+  fd = open(t.c_str(), O_WRONLY);
+  if (fd < 0) {
+    if (errno == ENOENT) {
+      fd = open(s.c_str(), O_WRONLY);
+      if (fd < 0)
+        return -errno;
+    } else {
+      return -errno;
+    }
+  }
+
+  r = safe_write(fd, buf.c_str(), buf.size());
+
+  close(fd);
+  return r;
+}
+
+static int sysfs_write_rbd_add(const string& buf)
+{
+  return sysfs_write_rbd("add", buf);
+}
+
+static int sysfs_write_rbd_remove(const string& buf)
+{
+  return sysfs_write_rbd("remove", buf);
+}
+
+static int have_minor_attr(void)
+{
+  /*
+   * 'minor' attribute was added as part of single_major merge, which
+   * exposed the 'single_major' parameter.  'minor' is always present,
+   * regardless of whether single-major scheme is turned on or not.
+   *
+   * (Something like ver >= KERNEL_VERSION(3, 14, 0) is a no-go because
+   * this has to work with rbd.ko backported to various kernels.)
+   */
+  return access("/sys/module/rbd/parameters/single_major", F_OK) == 0;
+}
+
+static int build_map_buf(CephContext *cct, const char *pool, const char *image,
+                         const char *snap, const char *options, string *pbuf)
+{
+  ostringstream oss;
+  int r;
+
+  MonMap monmap;
+  r = monmap.build_initial(cct, cerr);
+  if (r < 0)
+    return r;
+
+  list<entity_addr_t> mon_addr;
+  monmap.list_addrs(mon_addr);
+
+  for (const auto &p : mon_addr) {
+    if (oss.tellp() > 0) {
+      oss << ",";
+    }
+    oss << p.get_sockaddr();
+  }
+
+  oss << " name=" << cct->_conf->name.get_id();
+
+  KeyRing keyring;
+  if (cct->_conf->auth_client_required != "none") {
+    r = keyring.from_ceph_context(cct);
+    if (r == -ENOENT && !(cct->_conf->keyfile.length() ||
+                          cct->_conf->key.length()))
+      r = 0;
+    if (r < 0) {
+      cerr << "rbd: failed to get secret" << std::endl;
+      return r;
+    }
+  }
+
+  CryptoKey secret;
+  string key_name = string("client.") + cct->_conf->name.get_id();
+  if (keyring.get_secret(cct->_conf->name, secret)) {
+    string secret_str;
+    secret.encode_base64(secret_str);
+
+    r = set_kernel_secret(secret_str.c_str(), key_name.c_str());
+    if (r >= 0) {
+      if (r == 0)
+        cerr << "rbd: warning: secret has length 0" << std::endl;
+      oss << ",key=" << key_name;
+    } else if (r == -ENODEV || r == -ENOSYS) {
+      // running against older kernel; fall back to secret= in options
+      oss << ",secret=" << secret_str;
+    } else {
+      cerr << "rbd: failed to add secret '" << key_name << "' to kernel"
+           << std::endl;
+      return r;
+    }
+  } else if (is_kernel_secret(key_name.c_str())) {
+    oss << ",key=" << key_name;
+  }
+
+  if (strcmp(options, "") != 0)
+    oss << "," << options;
+
+  oss << " " << pool << " " << image << " " << snap;
+
+  *pbuf = oss.str();
+  return 0;
+}
+
+static int wait_for_udev_add(struct udev_monitor *mon, const char *pool,
+                             const char *image, const char *snap,
+                             string *pname)
+{
+  struct udev_device *bus_dev = NULL;
+
+  /*
+   * Catch /sys/devices/rbd/<id>/ and wait for the corresponding
+   * block device to show up.  This is necessary because rbd devices
+   * and block devices aren't linked together in our sysfs layout.
+   */
+  for (;;) {
+    struct pollfd fds[1];
+    struct udev_device *dev;
+
+    fds[0].fd = udev_monitor_get_fd(mon);
+    fds[0].events = POLLIN;
+    if (poll(fds, 1, POLL_TIMEOUT) < 0)
+      return -errno;
+
+    dev = udev_monitor_receive_device(mon);
+    if (!dev)
+      continue;
+
+    if (strcmp(udev_device_get_action(dev), "add") != 0)
+      goto next;
+
+    if (!bus_dev) {
+      if (strcmp(udev_device_get_subsystem(dev), "rbd") == 0) {
+        const char *this_pool = udev_device_get_sysattr_value(dev, "pool");
+        const char *this_image = udev_device_get_sysattr_value(dev, "name");
+        const char *this_snap = udev_device_get_sysattr_value(dev,
+                                                              "current_snap");
+
+        if (this_pool && strcmp(this_pool, pool) == 0 &&
+            this_image && strcmp(this_image, image) == 0 &&
+            this_snap && strcmp(this_snap, snap) == 0) {
+          bus_dev = dev;
+          continue;
+        }
+      }
+    } else {
+      if (strcmp(udev_device_get_subsystem(dev), "block") == 0) {
+        const char *major = udev_device_get_sysattr_value(bus_dev, "major");
+        const char *minor = udev_device_get_sysattr_value(bus_dev, "minor");
+        const char *this_major = udev_device_get_property_value(dev, "MAJOR");
+        const char *this_minor = udev_device_get_property_value(dev, "MINOR");
+
+        assert(!minor ^ have_minor_attr());
+
+        if (strcmp(this_major, major) == 0 &&
+            (!minor || strcmp(this_minor, minor) == 0)) {
+          string name = get_kernel_rbd_name(udev_device_get_sysname(bus_dev));
+
+          assert(strcmp(udev_device_get_devnode(dev), name.c_str()) == 0);
+          *pname = name;
+
+          udev_device_unref(dev);
+          udev_device_unref(bus_dev);
+          break;
+        }
+      }
+    }
+
+  next:
+    udev_device_unref(dev);
+  }
+
+  return 0;
+}
+
+static int do_map(struct udev *udev, const char *pool, const char *image,
+                  const char *snap, const string& buf, string *pname)
+{
+  struct udev_monitor *mon;
+  int r;
+
+  mon = udev_monitor_new_from_netlink(udev, "udev");
+  if (!mon)
+    return -ENOMEM;
+
+  r = udev_monitor_filter_add_match_subsystem_devtype(mon, "rbd", NULL);
+  if (r < 0)
+    goto out_mon;
+
+  r = udev_monitor_filter_add_match_subsystem_devtype(mon, "block", "disk");
+  if (r < 0)
+    goto out_mon;
+
+  r = udev_monitor_enable_receiving(mon);
+  if (r < 0)
+    goto out_mon;
+
+  r = sysfs_write_rbd_add(buf);
+  if (r < 0) {
+    cerr << "rbd: sysfs write failed" << std::endl;
+    goto out_mon;
+  }
+
+  r = wait_for_udev_add(mon, pool, image, snap, pname);
+  if (r < 0) {
+    cerr << "rbd: wait failed" << std::endl;
+    goto out_mon;
+  }
+
+out_mon:
+  udev_monitor_unref(mon);
+  return r;
+}
+
+static int map_image(struct krbd_ctx *ctx, const char *pool, const char *image,
+                     const char *snap, const char *options, string *pname)
+{
+  string buf;
+  int r;
+
+  if (strcmp(snap, "") == 0)
+    snap = "-";
+
+  r = build_map_buf(ctx->cct, pool, image, snap, options, &buf);
+  if (r < 0)
+    return r;
+
+  /*
+   * Modprobe rbd kernel module.  If it supports single-major device
+   * number allocation scheme, make sure it's turned on.
+   */
+  if (access("/sys/bus/rbd", F_OK) != 0) {
+    const char *module_options = NULL;
+    if (module_has_param("rbd", "single_major"))
+      module_options = "single_major=Y";
+
+    r = module_load("rbd", module_options);
+    if (r) {
+      cerr << "rbd: failed to load rbd kernel module (" << r << ")"
+           << std::endl;
+      /*
+       * Ignore the error: modprobe failing doesn't necessarily prevent
+       * from working.
+       */
+    }
+  }
+
+  return do_map(ctx->udev, pool, image, snap, buf, pname);
+}
+
+static int devno_to_krbd_id(struct udev *udev, dev_t devno, string *pid)
+{
+  struct udev_enumerate *enm;
+  struct udev_list_entry *l;
+  struct udev_device *dev;
+  int r;
+
+  enm = udev_enumerate_new(udev);
+  if (!enm)
+    return -ENOMEM;
+
+  r = udev_enumerate_add_match_subsystem(enm, "rbd");
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_add_match_sysattr(enm, "major",
+                                       stringify(major(devno)).c_str());
+  if (r < 0)
+    goto out_enm;
+
+  if (have_minor_attr()) {
+    r = udev_enumerate_add_match_sysattr(enm, "minor",
+                                         stringify(minor(devno)).c_str());
+    if (r < 0)
+      goto out_enm;
+  }
+
+  r = udev_enumerate_scan_devices(enm);
+  if (r < 0)
+    goto out_enm;
+
+  l = udev_enumerate_get_list_entry(enm);
+  if (!l) {
+    r = -ENOENT;
+    goto out_enm;
+  }
+
+  /* make sure there is only one match */
+  assert(!udev_list_entry_get_next(l));
+
+  dev = udev_device_new_from_syspath(udev, udev_list_entry_get_name(l));
+  if (!dev) {
+    r = -ENOMEM;
+    goto out_enm;
+  }
+
+  *pid = udev_device_get_sysname(dev);
+
+  udev_device_unref(dev);
+out_enm:
+  udev_enumerate_unref(enm);
+  return r;
+}
+
+static int spec_to_devno_and_krbd_id(struct udev *udev, const char *pool,
+                                     const char *image, const char *snap,
+                                     dev_t *pdevno, string *pid)
+{
+  struct udev_enumerate *enm;
+  struct udev_list_entry *l;
+  struct udev_device *dev;
+  unsigned int maj, min = 0;
+  string err;
+  int r;
+
+  enm = udev_enumerate_new(udev);
+  if (!enm)
+    return -ENOMEM;
+
+  r = udev_enumerate_add_match_subsystem(enm, "rbd");
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_add_match_sysattr(enm, "pool", pool);
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_add_match_sysattr(enm, "name", image);
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_add_match_sysattr(enm, "current_snap", snap);
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_scan_devices(enm);
+  if (r < 0)
+    goto out_enm;
+
+  l = udev_enumerate_get_list_entry(enm);
+  if (!l) {
+    r = -ENOENT;
+    goto out_enm;
+  }
+
+  dev = udev_device_new_from_syspath(udev, udev_list_entry_get_name(l));
+  if (!dev) {
+    r = -ENOMEM;
+    goto out_enm;
+  }
+
+  maj = strict_strtoll(udev_device_get_sysattr_value(dev, "major"), 10, &err);
+  if (!err.empty()) {
+    cerr << "rbd: couldn't parse major: " << err << std::endl;
+    r = -EINVAL;
+    goto out_dev;
+  }
+  if (have_minor_attr()) {
+    min = strict_strtoll(udev_device_get_sysattr_value(dev, "minor"), 10, &err);
+    if (!err.empty()) {
+      cerr << "rbd: couldn't parse minor: " << err << std::endl;
+      r = -EINVAL;
+      goto out_dev;
+    }
+  }
+
+  /*
+   * If an image is mapped more than once don't bother trying to unmap
+   * all devices - let users run unmap the same number of times they
+   * ran map.
+   */
+  if (udev_list_entry_get_next(l))
+    cerr << "rbd: " << pool << "/" << image << "@" << snap
+         << ": mapped more than once, unmapping "
+         << get_kernel_rbd_name(udev_device_get_sysname(dev))
+         << " only" << std::endl;
+
+  *pdevno = makedev(maj, min);
+  *pid = udev_device_get_sysname(dev);
+
+out_dev:
+  udev_device_unref(dev);
+out_enm:
+  udev_enumerate_unref(enm);
+  return r;
+}
+
+static string build_unmap_buf(const string& id, const char *options)
+{
+  string buf(id);
+  if (strcmp(options, "") != 0) {
+    buf += " ";
+    buf += options;
+  }
+  return buf;
+}
+
+static int wait_for_udev_remove(struct udev_monitor *mon, dev_t devno)
+{
+  for (;;) {
+    struct pollfd fds[1];
+    struct udev_device *dev;
+
+    fds[0].fd = udev_monitor_get_fd(mon);
+    fds[0].events = POLLIN;
+    if (poll(fds, 1, POLL_TIMEOUT) < 0)
+      return -errno;
+
+    dev = udev_monitor_receive_device(mon);
+    if (!dev)
+      continue;
+
+    if (strcmp(udev_device_get_action(dev), "remove") == 0 &&
+        udev_device_get_devnum(dev) == devno) {
+      udev_device_unref(dev);
+      break;
+    }
+
+    udev_device_unref(dev);
+  }
+
+  return 0;
+}
+
+static int do_unmap(struct udev *udev, dev_t devno, const string& buf)
+{
+  struct udev_monitor *mon;
+  int r;
+
+  mon = udev_monitor_new_from_netlink(udev, "udev");
+  if (!mon)
+    return -ENOMEM;
+
+  r = udev_monitor_filter_add_match_subsystem_devtype(mon, "block", "disk");
+  if (r < 0)
+    goto out_mon;
+
+  r = udev_monitor_enable_receiving(mon);
+  if (r < 0)
+    goto out_mon;
+
+  /*
+   * On final device close(), kernel sends a block change event, in
+   * response to which udev apparently runs blkid on the device.  This
+   * makes unmap fail with EBUSY, if issued right after final close().
+   * Try to circumvent this with a retry before turning to udev.
+   */
+  for (int tries = 0; ; tries++) {
+    r = sysfs_write_rbd_remove(buf);
+    if (r >= 0) {
+      break;
+    } else if (r == -EBUSY && tries < 2) {
+      if (!tries) {
+        usleep(250 * 1000);
+      } else {
+        /*
+         * libudev does not provide the "wait until the queue is empty"
+         * API or the sufficient amount of primitives to build it from.
+         */
+        string err = run_cmd("udevadm", "settle", "--timeout", "10", NULL);
+        if (!err.empty())
+          cerr << "rbd: " << err << std::endl;
+      }
+    } else {
+      cerr << "rbd: sysfs write failed" << std::endl;
+      goto out_mon;
+    }
+  }
+
+  r = wait_for_udev_remove(mon, devno);
+  if (r < 0) {
+    cerr << "rbd: wait failed" << std::endl;
+    goto out_mon;
+  }
+
+out_mon:
+  udev_monitor_unref(mon);
+  return r;
+}
+
+static int unmap_image(struct krbd_ctx *ctx, const char *devnode,
+                       const char *options)
+{
+  struct stat sb;
+  dev_t wholedevno = 0;
+  string id;
+  int r;
+
+  if (stat(devnode, &sb) < 0 || !S_ISBLK(sb.st_mode)) {
+    cerr << "rbd: '" << devnode << "' is not a block device" << std::endl;
+    return -EINVAL;
+  }
+
+  r = blkid_devno_to_wholedisk(sb.st_rdev, NULL, 0, &wholedevno);
+  if (r < 0) {
+    cerr << "rbd: couldn't compute wholedevno: " << cpp_strerror(r)
+         << std::endl;
+    /*
+     * Ignore the error: we are given whole disks most of the time, and
+     * if it turns out this is a partition we will fail later anyway.
+     */
+    wholedevno = sb.st_rdev;
+  }
+
+  r = devno_to_krbd_id(ctx->udev, wholedevno, &id);
+  if (r < 0) {
+    if (r == -ENOENT) {
+      cerr << "rbd: '" << devnode << "' is not an rbd device" << std::endl;
+      r = -EINVAL;
+    }
+    return r;
+  }
+
+  return do_unmap(ctx->udev, wholedevno, build_unmap_buf(id, options));
+}
+
+static int unmap_image(struct krbd_ctx *ctx, const char *pool,
+                       const char *image, const char *snap,
+                       const char *options)
+{
+  dev_t devno = 0;
+  string id;
+  int r;
+
+  if (!snap)
+    snap = "-";
+
+  r = spec_to_devno_and_krbd_id(ctx->udev, pool, image, snap, &devno, &id);
+  if (r < 0) {
+    if (r == -ENOENT) {
+      cerr << "rbd: " << pool << "/" << image << "@" << snap
+           << ": not a mapped image or snapshot" << std::endl;
+      r = -EINVAL;
+    }
+    return r;
+  }
+
+  return do_unmap(ctx->udev, devno, build_unmap_buf(id, options));
+}
+
+static bool dump_one_image(Formatter *f, TextTable *tbl,
+                           struct udev_device *dev)
+{
+  const char *id = udev_device_get_sysname(dev);
+  const char *pool = udev_device_get_sysattr_value(dev, "pool");
+  const char *image = udev_device_get_sysattr_value(dev, "name");
+  const char *snap = udev_device_get_sysattr_value(dev, "current_snap");
+  string kname = get_kernel_rbd_name(id);
+
+  if (!pool || !image || !snap)
+    return false;
+
+  if (f) {
+    f->open_object_section(id);
+    f->dump_string("pool", pool);
+    f->dump_string("name", image);
+    f->dump_string("snap", snap);
+    f->dump_string("device", kname);
+    f->close_section();
+  } else {
+    *tbl << id << pool << image << snap << kname << TextTable::endrow;
+  }
+
+  return true;
+}
+
+static int do_dump(struct udev *udev, Formatter *f, TextTable *tbl)
+{
+  struct udev_enumerate *enm;
+  struct udev_list_entry *l;
+  bool have_output = false;
+  int r;
+
+  enm = udev_enumerate_new(udev);
+  if (!enm)
+    return -ENOMEM;
+
+  r = udev_enumerate_add_match_subsystem(enm, "rbd");
+  if (r < 0)
+    goto out_enm;
+
+  r = udev_enumerate_scan_devices(enm);
+  if (r < 0)
+    goto out_enm;
+
+  udev_list_entry_foreach(l, udev_enumerate_get_list_entry(enm)) {
+    struct udev_device *dev;
+
+    dev = udev_device_new_from_syspath(udev, udev_list_entry_get_name(l));
+    if (dev) {
+      have_output |= dump_one_image(f, tbl, dev);
+      udev_device_unref(dev);
+    }
+  }
+
+  r = have_output;
+out_enm:
+  udev_enumerate_unref(enm);
+  return r;
+}
+
+int dump_images(struct krbd_ctx *ctx, Formatter *f)
+{
+  TextTable tbl;
+  int r;
+
+  if (f) {
+    f->open_object_section("devices");
+  } else {
+    tbl.define_column("id", TextTable::LEFT, TextTable::LEFT);
+    tbl.define_column("pool", TextTable::LEFT, TextTable::LEFT);
+    tbl.define_column("image", TextTable::LEFT, TextTable::LEFT);
+    tbl.define_column("snap", TextTable::LEFT, TextTable::LEFT);
+    tbl.define_column("device", TextTable::LEFT, TextTable::LEFT);
+  }
+
+  r = do_dump(ctx->udev, f, &tbl);
+
+  if (f) {
+    f->close_section();
+    f->flush(cout);
+  } else {
+    if (r > 0)
+      cout << tbl;
+  }
+
+  return r;
+}
+
+extern "C" int krbd_create_from_context(rados_config_t cct,
+                                        struct krbd_ctx **pctx)
+{
+  struct krbd_ctx *ctx = new struct krbd_ctx();
+
+  ctx->cct = reinterpret_cast<CephContext *>(cct);
+  ctx->udev = udev_new();
+  if (!ctx->udev) {
+    delete ctx;
+    return -ENOMEM;
+  }
+
+  *pctx = ctx;
+  return 0;
+}
+
+extern "C" void krbd_destroy(struct krbd_ctx *ctx)
+{
+  if (!ctx)
+    return;
+
+  udev_unref(ctx->udev);
+
+  delete ctx;
+}
+
+extern "C" int krbd_map(struct krbd_ctx *ctx, const char *pool,
+                        const char *image, const char *snap,
+                        const char *options, char **pdevnode)
+{
+  string name;
+  char *devnode;
+  int r;
+
+  r = map_image(ctx, pool, image, snap, options, &name);
+  if (r < 0)
+    return r;
+
+  devnode = strdup(name.c_str());
+  if (!devnode)
+    return -ENOMEM;
+
+  *pdevnode = devnode;
+  return r;
+}
+
+extern "C" int krbd_unmap(struct krbd_ctx *ctx, const char *devnode,
+                          const char *options)
+{
+  return unmap_image(ctx, devnode, options);
+}
+
+extern "C" int krbd_unmap_by_spec(struct krbd_ctx *ctx, const char *pool,
+                                  const char *image, const char *snap,
+                                  const char *options)
+{
+  return unmap_image(ctx, pool, image, snap, options);
+}
+
+int krbd_showmapped(struct krbd_ctx *ctx, Formatter *f)
+{
+  return dump_images(ctx, f);
+}