diff options
Diffstat (limited to 'internal/fusefrontend/write_lock.go')
| -rw-r--r-- | internal/fusefrontend/write_lock.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/internal/fusefrontend/write_lock.go b/internal/fusefrontend/write_lock.go index 2f8ea4e..7394994 100644 --- a/internal/fusefrontend/write_lock.go +++ b/internal/fusefrontend/write_lock.go @@ -2,6 +2,7 @@ package fusefrontend import ( "sync" + "sync/atomic" ) func init() { @@ -20,6 +21,12 @@ var wlock wlockMap // 2) lock ... unlock ... // 3) unregister type wlockMap struct { + // Counts lock() calls. As every operation that modifies a file should + // call it, this effectively serves as a write-operation counter. + // The variable is accessed without holding any locks so atomic operations + // must be used. It must be the first element of the struct to guarantee + // 64-bit alignment. + opCount uint64 // Protects map access sync.Mutex inodeLocks map[uint64]*refCntMutex @@ -62,6 +69,7 @@ func (w *wlockMap) unregister(ino uint64) { // lock retrieves the entry for "ino" and locks it. func (w *wlockMap) lock(ino uint64) { + atomic.AddUint64(&w.opCount, 1) w.Lock() r := w.inodeLocks[ino] w.Unlock() |