On Thu, Nov 16, 2017 at 03:10:39PM -0600, Eric Sandeen wrote:
>
>
> On 11/15/17 7:14 PM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> >
> > If xfs_copy is told to copy a filesystem and /all/ the writer threads
> > hit an write error, there won't be any threads to unlock mainwait, which
> > means that write_wbuf will deadlock with itself trying to lock mainwait.
> > Therefore, if we discover that all the writer threads are dead, just
> > bail out.
> >
> > Discovered by running xfs/073 with a tiny test device.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
> > copy/xfs_copy.c | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c
> > index 33e05df..fb37375 100644
> > --- a/copy/xfs_copy.c
> > +++ b/copy/xfs_copy.c
> > @@ -476,6 +476,7 @@ void
> > write_wbuf(void)
> > {
> > int i;
> > + int badness = 0;
> >
> > /* verify target threads */
> > for (i = 0; i < num_targets; i++)
> > @@ -486,6 +487,17 @@ write_wbuf(void)
> > for (i = 0; i < num_targets; i++)
> > if (target[i].state != INACTIVE)
> > pthread_mutex_unlock(&targ[i].wait); /* wake up */
> > + else
> > + badness++;
> > +
> > + /*
> > + * If all the targets are inactive then there won't be any io
> > + * threads left to release mainwait. We're screwed, so bail out.
> > + */
> > + if (badness == num_targets) {
> > + check_errors();
>
> libxfs_umount(mp); ?
Doh. v2 on its way
--D
> -Eric
>
> > + exit(1);
> > + }
> >
> > signal_maskfunc(SIGCHLD, SIG_UNBLOCK);
> > pthread_mutex_lock(&mainwait);
> > --
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> >
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