fixed logics for grabbing new tape correctly

tapebackup/utils/tapemanager.py

@@ -33,7 +33,7 @@ class TapeManager:
     def __init__(self, dbsession):
         self.changer_device = '/dev/sg4'
         self.tape_drive_device = '/dev/sg3'
-        self.mkltfs_binary = '/usr/local/bin/mkltfs '
+        self.mkltfs_binary = '/usr/local/bin/mkltfs'
         # canonical mount "/usr/local/bin/ltfs /mnt/tape/ -o devname=/dev/sg3"
         self.mountpoint = None
         self.mountpoint_base = "/srv_mount_dont_go_here/tapes/"
@@ -57,9 +57,8 @@ class TapeManager:
         return label, is_data_tape
 
     def disk_usage(self):
-        if self.mountcheck():
-            self.mountpoint = mountpoint = self.mountpoint_base + self.drives[0][self.PRIMARY_VOLUME_TAG]
-        else:
+        if not self.mountcheck():
+            self.mountpoint = None
             self.df = 0
             return
         total, used, free = shutil.disk_usage(self.mountpoint)
@@ -75,17 +74,24 @@ class TapeManager:
         self.df = really_free
 
     def mountcheck(self):
-        self.mountpoint = self.mountpoint_base + self.drives[0][self.PRIMARY_VOLUME_TAG]
-        if os.path.ismount(self.mountpoint):
+        if self.drives[0].get(self.PRIMARY_VOLUME_TAG):
+            mountpoint = self.mountpoint_base + self.drives[0][self.PRIMARY_VOLUME_TAG]
+        else:
+            self.mountpoint = None
+            return False
+        if os.path.ismount(mountpoint):
             log.info("Tape %s is mounted to %s" % (self.drives[0][self.PRIMARY_VOLUME_TAG], mountpoint))
+            self.mountpoint = mountpoint
             return True
         else:
+            self.mountpoint = None
             return False
 
     # return true for successful mount, false for unsuccessful
     def mount(self):
         if self.drive_state != DriveState.data_tape_inside:
             raise Exception("Trying to mount without data tape inside")
+        # NOTE: caution, don't try to have here "self.mountpoint", it's illegal
         mountpoint = self.mountpoint_base + self.drives[0][self.PRIMARY_VOLUME_TAG]
         mkdir_completed = subprocess.run(["mkdir", "-p", "-v", mountpoint], capture_output=True, shell=False)
         if mkdir_completed.returncode != 0:
@@ -103,7 +109,11 @@ class TapeManager:
     def format(self):
         if self.drive_state != DriveState.data_tape_inside:
             raise Exception("Trying to mount without data tape inside")
-        mkltfs_completed = subprocess.run([self.mkltfs_binary, self.tape_drive_device], capture_output=True, shell=False)
+        vol_name = self.drives[0][self.PRIMARY_VOLUME_TAG]
+        mkltfs_completed = subprocess.run([self.mkltfs_binary,
+                                           '-d', self.tape_drive_device,
+                                           '-n', self.drives[0][self.PRIMARY_VOLUME_TAG],
+                                           '--syslogtrace'], capture_output=True, shell=False)
         return True if mkltfs_completed.returncode == 0 else False
 
     def finalize_tape(self):
@@ -114,7 +124,7 @@ class TapeManager:
             # Also checksumming process seems to take more time that rsync itself.
             tape = self.identify_tape()
             tape.state = models.TapeState.finalized
-            pathlib.touch(self.mountpoint + "/finalized.txt")
+            pathlib.Path(self.mountpoint + "/finalized.txt").touch()
             log.info("Finalized")
             self.eject_current_tape_to_empty_magazine_slot()
             log.info("Ejected to magazine")
@@ -146,8 +156,8 @@ class TapeManager:
     # tape rotation mechanism
     def eject_current_tape_to_empty_magazine_slot(self):
         if self.mountcheck():
-            mountpoint = "/srv_mount_dont_go_here/tapes/" + self.drives[0][self.PRIMARY_VOLUME_TAG]
-            umount_completed = subprocess.run([self.umount_command, mountpoint], capture_output=True, shell=False)
+            log.info("Tape is mounted; need to unmount first")
+            umount_completed = subprocess.run([self.umount_command, self.mountpoint], capture_output=True, shell=False)
             if umount_completed.returncode:
                 raise Exception("Failed to unmount => can not move tape. Try again when tape is not used.")
             else:
@@ -159,6 +169,7 @@ class TapeManager:
             raise Exception("No available slots in magazine; it's critical to have exactly 35 tapes in magazines!")
         else:
             self.eject_to(empty_slot)
+            self.scan()
 
     # Scan for data tape slots
     def scan_drives(self, device, element_address_assignment):
@@ -285,6 +296,8 @@ class TapeManager:
             log.info("Tape is already in drive")
             return
         device = SCSI(init_device(self.changer_device))
+        if self.drives[0]['full']:
+            self.eject_current_tape_to_empty_magazine_slot()
         device.movemedium(self.robot[0]['element_address'], slot, self.drives[0]['element_address'])
         log.info("Moving tape from slot %d to drive", slot)
         return
@@ -296,6 +309,7 @@ class TapeManager:
             raise Exception("Drive is empty; nothing to eject.")
         # umount is **obligatory**, otherwise it hangs to death
         movemedium = device.movemedium(self.robot[0]['element_address'], self.drives[0]['element_address'], slot)
+        log.info("Moved tape from %d to slot %d", self.drives[0]['element_address'], slot)
         return movemedium
 
     def get_drive_state(self):