#define _AFS_VOL_VOLUME_INLINE_H 1
#include "volume.h"
+#include "partition.h"
+
+#ifdef AFS_DEMAND_ATTACH_FS
+# include "lock.h"
+#endif
+
/**
* tell caller whether the given program type represents a salvaging
* program.
switch(type) {
case salvager:
case salvageServer:
+ case volumeSalvager:
return 1;
default:
return 0;
}
}
+/**
+ * tells caller whether or not we need to lock the entire partition when
+ * attaching a volume.
+ *
+ * @return whether or not we need to lock the partition
+ * @retval 0 no, we do not
+ * @retval 1 yes, we do
+ *
+ * @note for DAFS, always returns 0, since we use per-header locks instead
+ */
+static_inline int
+VRequiresPartLock(void)
+{
+#ifdef AFS_DEMAND_ATTACH_FS
+ return 0;
+#else
+ switch (programType) {
+ case volumeServer:
+ case volumeUtility:
+ return 1;
+ default:
+ return 0;
+ }
+#endif /* AFS_DEMAND_ATTACH_FS */
+}
+
+/**
+ * tells caller whether or not we need to check out a volume from the
+ * fileserver before we can use it.
+ *
+ * @param[in] mode the mode of attachment for the volume
+ *
+ * @return whether or not we need to check out the volume from the fileserver
+ * @retval 0 no, we can just use the volume
+ * @retval 1 yes, we must check out the volume before use
+ */
+static_inline int
+VMustCheckoutVolume(int mode)
+{
+ if (VCanUseFSSYNC() && mode != V_SECRETLY && mode != V_PEEK) {
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * tells caller whether we should check the inUse field in the volume
+ * header when attaching a volume.
+ *
+ * If we check inUse, that generally means we will salvage the volume
+ * (or put it in an error state) if we detect that another program
+ * claims to be using the volume when we try to attach. We don't always
+ * want to do that, since sometimes we know that the volume may be in
+ * use by another program, e.g. when we are attaching with V_PEEK, and
+ * we don't care.
+ *
+ * @param mode the mode of attachment for the volume
+ *
+ * @return whether or not we should check inUse
+ * @retval 0 no, we should not check inUse
+ * @retval 1 yes, we should check inUse
+ */
+static_inline int
+VShouldCheckInUse(int mode)
+{
+ if (VCanUnsafeAttach()) {
+ return 0;
+ }
+ if (programType == fileServer) {
+ return 1;
+ }
+ if (VMustCheckoutVolume(mode)) {
+ /* assume we checked out the volume from the fileserver, so inUse
+ * should not be set */
+ return 1;
+ }
+ return 0;
+}
+
+#ifdef AFS_DEMAND_ATTACH_FS
+/**
+ * acquire a non-blocking disk lock for a particular volume id.
+ *
+ * @param[in] volid the volume ID to lock
+ * @param[in] dp the partition on which 'volid' resides
+ * @param[in] locktype READ_LOCK or WRITE_LOCK
+ *
+ * @return operation status
+ * @retval 0 success, lock was obtained
+ * @retval EBUSY another process holds a conflicting lock
+ * @retval EIO error acquiring lock
+ *
+ * @note Use VLockVolumeNB instead, if possible; only use this directly if
+ * you are not dealing with 'Volume*'s and attached volumes and such
+ *
+ * @pre There must not be any other threads acquiring locks on the same volid
+ * and partition; the locks will not work correctly if two threads try to
+ * acquire locks for the same volume
+ */
+static_inline int
+VLockVolumeByIdNB(VolumeId volid, struct DiskPartition64 *dp, int locktype)
+{
+ return VLockFileLock(&dp->volLockFile, volid, locktype, 1 /* nonblock */);
+}
+
+/**
+ * release a lock acquired by VLockVolumeByIdNB.
+ *
+ * @param[in] volid the volume id to unlock
+ * @param[in] dp the partition on which 'volid' resides
+ *
+ * @pre volid was previously locked by VLockVolumeByIdNB
+ */
+static_inline void
+VUnlockVolumeById(VolumeId volid, struct DiskPartition64 *dp)
+{
+ VLockFileUnlock(&dp->volLockFile, volid);
+}
+
/***************************************************/
/* demand attach fs state machine routines */
/***************************************************/
-#ifdef AFS_DEMAND_ATTACH_FS
+/**
+ * tells caller whether we need to keep volumes locked for the entire time we
+ * are using them, or if we can unlock volumes as soon as they are attached.
+ *
+ * @return whether we can unlock attached volumes or not
+ * @retval 1 yes, we can unlock attached volumes
+ * @retval 0 no, do not unlock volumes until we unattach them
+ */
+static_inline int
+VCanUnlockAttached(void)
+{
+ switch(programType) {
+ case fileServer:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/**
+ * tells caller whether we need to lock a vol header with a write lock, a
+ * read lock, or if we do not need to lock it at all, when attaching.
+ *
+ * @param[in] mode volume attachment mode
+ * @param[in] writeable 1 if the volume is writable, 0 if not
+ *
+ * @return how we need to lock the vol header
+ * @retval 0 do not lock the vol header at all
+ * @retval READ_LOCK lock the vol header with a read lock
+ * @retval WRITE_LOCK lock the vol header with a write lock
+ *
+ * @note DAFS only (non-DAFS uses partition locks)
+ */
+static_inline int
+VVolLockType(int mode, int writeable)
+{
+ switch (programType) {
+ case fileServer:
+ if (writeable) {
+ return WRITE_LOCK;
+ }
+ return READ_LOCK;
+
+ case volumeSalvager:
+ case salvageServer:
+ case salvager:
+ return WRITE_LOCK;
+
+ default:
+ /* volserver, vol utilies, etc */
+
+ switch (mode) {
+ case V_READONLY:
+ return READ_LOCK;
+
+ case V_VOLUPD:
+ case V_SECRETLY:
+ return WRITE_LOCK;
+
+ case V_CLONE:
+ case V_DUMP:
+ if (writeable) {
+ return WRITE_LOCK;
+ }
+ return READ_LOCK;
+
+ case V_PEEK:
+ return 0;
+
+ default:
+ assert(0 /* unknown checkout mode */);
+ return 0;
+ }
+ }
+}
+
/**
* tells caller whether or not the current state requires
* exclusive access without holding glock.
case VOL_STATE_VNODE_GET:
case VOL_STATE_VNODE_CLOSE:
case VOL_STATE_VNODE_RELEASE:
+ case VOL_STATE_VLRU_ADD:
return 1;
+ default:
+ return 0;
}
- return 0;
}
/**
case VOL_STATE_ERROR:
case VOL_STATE_SALVAGING:
return 1;
+ default:
+ return 0;
}
- return 0;
}
/**
case VOL_STATE_ERROR:
case VOL_STATE_SALVAGING:
return 1;
+ default:
+ return 0;
}
- return 0;
}
/**
#endif /* AFS_DEMAND_ATTACH_FS */
+#define VENUMCASE(en) \
+ case en: \
+ return #en; \
+ break
+
+/**
+ * translate a ProgramType code to a string.
+ *
+ * @param[in] type ProgramType numeric code
+ *
+ * @return a human-readable string for that program type
+ * @retval "**UNKNOWN**" an unknown ProgramType was given
+ */
+static_inline char *
+VPTypeToString(ProgramType type)
+{
+ switch (type) {
+ VENUMCASE(fileServer);
+ VENUMCASE(volumeUtility);
+ VENUMCASE(salvager);
+ VENUMCASE(salvageServer);
+ VENUMCASE(debugUtility);
+ VENUMCASE(volumeServer);
+ VENUMCASE(volumeSalvager);
+ default:
+ return "**UNKNOWN**";
+ }
+}
+
+#undef VENUMCASE
+
#endif /* _AFS_VOL_VOLUME_INLINE_H */
git://git.openafs.org / openafs.git / blobdiff