filestore: tolerate missing current/

We remove it anyway.  If it's missing entirely, just continue and roll
back to the latest snap_ when the user passes --osd-use-stale-snap.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
index 79d254bd8a5105548f14636deabc8ae692e38c7b..8eb5bd4da5ca41c585bddc5b3262e2b4e7f1e70e 100644 (file)
--- a/src/os/FileStore.cc
+++ b/src/os/FileStore.cc
@@ -1486,6 +1486,7 @@ int FileStore::mount()
       dout(0) << "mount WARNING: not btrfs, store may be in inconsistent state" << dendl;
     } else {
       char s[PATH_MAX];
+      uint64_t curr_seq = 0;
 
       if (m_osd_rollback_to_cluster_snap.length()) {
        derr << TEXT_RED
@@ -1496,13 +1497,16 @@ int FileStore::mount()
        snprintf(s, sizeof(s), "%s/" CLUSTER_SNAP_ITEM, basedir.c_str(),
                 m_osd_rollback_to_cluster_snap.c_str());
       } else {
-       uint64_t curr_seq;
        {
          int fd = read_op_seq(current_op_seq_fn.c_str(), &curr_seq);
-         assert(fd >= 0);
-         TEMP_FAILURE_RETRY(::close(fd));
+         if (fd >= 0) {
+           TEMP_FAILURE_RETRY(::close(fd));
+         }
        }
-       dout(10) << " current/ seq was " << curr_seq << dendl;
+       if (curr_seq)
+         dout(10) << " current/ seq was " << curr_seq << dendl;
+       else
+         dout(10) << " current/ missing entirely (unusual, but okay)" << dendl;
 
        uint64_t cp = snaps.back();
        dout(10) << " most recent snap from " << snaps << " is " << cp << dendl;
@@ -1510,7 +1514,7 @@ int FileStore::mount()
        if (cp != curr_seq) {
          if (!m_osd_use_stale_snap) { 
            derr << TEXT_RED
-                << " ** ERROR: current volume data version is not equal to snapshotted version\n"
+                << " ** ERROR: current/ volume data version is not equal to snapshotted version\n"
                 << "           which can lead to data inconsistency. \n"
                 << "           Current version " << curr_seq << ", last snap " << cp << "\n"
                 << "           Startup with snapshotted version can be forced using the\n"
@@ -1529,24 +1533,27 @@ int FileStore::mount()
        snprintf(s, sizeof(s), "%s/" COMMIT_SNAP_ITEM, basedir.c_str(), (long long unsigned)cp);
       }
 
-      // drop current
       btrfs_ioctl_vol_args vol_args;
       vol_args.fd = 0;
       strcpy(vol_args.name, "current");
-      ret = ::ioctl(basedir_fd,
+
+      // drop current?
+      if (curr_seq > 0) {
+       ret = ::ioctl(basedir_fd,
                      BTRFS_IOC_SNAP_DESTROY,
                      &vol_args);
-      if (ret) {
-       ret = errno;
-       derr << "FileStore::mount: error removing old current subvol: "
-            << cpp_strerror(ret) << dendl;
-       char s[PATH_MAX];
-       snprintf(s, sizeof(s), "%s/current.remove.me.%d", basedir.c_str(), rand());
-       if (::rename(current_fn.c_str(), s)) {
-         ret = -errno;
-         derr << "FileStore::mount: error renaming old current subvol: "
+       if (ret) {
+         ret = errno;
+         derr << "FileStore::mount: error removing old current subvol: "
               << cpp_strerror(ret) << dendl;
-         goto close_basedir_fd;
+         char s[PATH_MAX];
+         snprintf(s, sizeof(s), "%s/current.remove.me.%d", basedir.c_str(), rand());
+         if (::rename(current_fn.c_str(), s)) {
+           ret = -errno;
+           derr << "FileStore::mount: error renaming old current subvol: "
+                << cpp_strerror(ret) << dendl;
+           goto close_basedir_fd;
+         }
        }
       }