On Wed, Sep 16, 2015 at 08:39:09AM +0000, Junichi Nomura wrote: > filemap_fdatawait() is a function to wait for on-going writeback > to complete but also consume and clear error status of the mapping > set during writeback. > The latter functionality is critical for applications to detect > writeback error with system calls like fsync(2)/fdatasync(2). > > However filemap_fdatawait() is also used by sync(2) or FIFREEZE > ioctl, which don't check error status of individual mappings. > > As a result, fsync() may not be able to detect writeback error > if events happen in the following order: > > Application System admin > ---------------------------------------------------------- > write data on page cache > Run sync command > writeback completes with error > filemap_fdatawait() clears error > fsync returns success > (but the data is not on disk) > > This patch adds filemap_fdatawait_keep_errors() for call sites where > writeback error is not handled so that they don't clear error status. > > Signed-off-by: Jun'ichi Nomura <[email protected]> > Acked-by: Andi Kleen <[email protected]>
Reviewed-by: Tejun Heo <[email protected]> Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
