Bug 918140 - mis-interprets disk "hard quota" (blocks vs bytes confusion). r=benjamin

xpcom/io/nsLocalFileUnix.cpp

@@ -11,6 +11,7 @@
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/Attributes.h"
 
+#include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
@@ -1407,10 +1408,9 @@ nsLocalFile::GetDiskSpaceAvailable(int64_t* aDiskSpaceAvailable)
 #endif
       && dq.dqb_bhardlimit) {
     int64_t QuotaSpaceAvailable = 0;
-    if (dq.dqb_bhardlimit > dq.dqb_curspace) {
-      QuotaSpaceAvailable =
-        int64_t(fs_buf.F_BSIZE * (dq.dqb_bhardlimit - dq.dqb_curspace));
-    }
+    // dqb_bhardlimit is count of BLOCK_SIZE blocks, dqb_curspace is bytes
+    if ((BLOCK_SIZE * dq.dqb_bhardlimit) > dq.dqb_curspace)
+      QuotaSpaceAvailable = int64_t(BLOCK_SIZE * dq.dqb_bhardlimit - dq.dqb_curspace);
     if (QuotaSpaceAvailable < *aDiskSpaceAvailable) {
       *aDiskSpaceAvailable = QuotaSpaceAvailable;
     }