Possible bug with issuing sync from two open terminals

[Patrick O'Callaghan]

On Mon, 2009-06-01 at 20:07 -0700, Leslie Satenstein wrote:
> Either there was something wrong with the flash drive, or something
> else is wrong, but I noted that issuing the second sync command from
> the second terminal while the fist sync command was being executed
> resulted in the corruption of the flash drive file system (fat32).
> Does the sync command serialize it's operation?

The sync command just invokes the sync system call. It should always be
possible to issue multiple overlapping syncs with no ill-effects.

If sync(2) is really failing then there is a serious kernel-level
problem. However it seems more likely that the corruption is being
caused by something else, e.g. a physical problem with the pen drive or
a flaky USB interface.

poc