fuse_remount.h

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#ifndef CVMFS_FUSE_REMOUNT_H_
#define CVMFS_FUSE_REMOUNT_H_

#include <pthread.h>

#include <ctime>

#include "crypto/hash.h"
#include "duplex_fuse.h"
#include "fence.h"
#include "fuse_evict.h"
#include "util/atomic.h"
#include "util/single_copy.h"

namespace cvmfs {
struct InodeGenerationInfo;
}
class MountPoint;

class FuseRemounter : SingleCopy {
 public:
  enum Status {
    kStatusUp2Date = 0,
    kStatusDraining,
    kStatusMaintenance,
    kStatusFailGeneral,
    kStatusFailNoSpace,
  };

  FuseRemounter(MountPoint *mountpoint,
                cvmfs::InodeGenerationInfo *inode_generation_info,
                void **fuse_channel_or_session,
                bool fuse_notify_invalidation);
  ~FuseRemounter();
  void Spawn();

  Status Check();
  Status CheckSynchronously();
  Status ChangeRoot(const shash::Any &root_hash);
  void TryFinish(const shash::Any &root_hash = shash::Any());
  void EnterMaintenanceMode();
  bool IsCaching() {
    return (atomic_read32(&maintenance_mode_) == 0) &&
           (atomic_read32(&drainout_mode_) == 0);
  }
  bool IsInDrainoutMode() { return atomic_read32(&drainout_mode_) == 2; }
  bool IsInMaintenanceMode() { return atomic_read32(&maintenance_mode_) == 1; }

  Fence *fence() { return fence_; }
  time_t catalogs_valid_until() { return catalogs_valid_until_; }

  void InvalidateDentry(uint64_t parent_ino, const NameString &name) {
    invalidator_->InvalidateDentry(parent_ino, name);
  }

 private:
  static void *MainRemountTrigger(void *data);

  bool HasRemountTrigger() { return pipe_remount_trigger_[0] >= 0; }
  void SetAlarm(int timeout);

  bool EnterCriticalSection() {
    return atomic_cas32(&critical_section_, 0, 1);
  }
  void LeaveCriticalSection() { atomic_dec32(&critical_section_); /* 1 -> 0 */ }

  void SetOfflineMode(bool value);

  MountPoint *mountpoint_;  
  cvmfs::InodeGenerationInfo *inode_generation_info_;  
  FuseInvalidator *invalidator_;
  FuseInvalidator::Handle invalidator_handle_;
  Fence *fence_;
  Fence fence_maintenance_;
  pthread_t thread_remount_trigger_;
  int pipe_remount_trigger_[2];
  bool offline_mode_;
  time_t catalogs_valid_until_;
  atomic_int32 drainout_mode_;
  atomic_int32 maintenance_mode_;
  atomic_int32 critical_section_;
};  // class FuseRemounter

#endif  // CVMFS_FUSE_REMOUNT_H_