| Message ID | 20171003143416.12188-1-hch@lst.de (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Tue, Oct 03, 2017 at 04:34:16PM +0200, Christoph Hellwig wrote: > If we got two AIO writes into a COW area the second one might not have any > COW extents left to convert. Handle that case gracefully instead of > triggering an assert or accessing beyond the bounds of the extent list. > > Signed-off-by: Christoph Hellwig <hch@lst.de> Looks ok, will test. Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > fs/xfs/xfs_reflink.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 3246815c24d6..37e603bf1591 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -736,7 +736,13 @@ xfs_reflink_end_cow( > /* If there is a hole at end_fsb - 1 go to the previous extent */ > if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) || > got.br_startoff > end_fsb) { > - ASSERT(idx > 0); > + /* > + * In case of racing, overlapping AIO writes no COW extents > + * might be left by the time I/O completes for the loser of > + * the race. In that case we are done. > + */ > + if (idx <= 0) > + goto out_cancel; > xfs_iext_get_extent(ifp, --idx, &got); > } > > @@ -809,6 +815,7 @@ xfs_reflink_end_cow( > > out_defer: > xfs_defer_cancel(&dfops); > +out_cancel: > xfs_trans_cancel(tp); > xfs_iunlock(ip, XFS_ILOCK_EXCL); > out: > -- > 2.14.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 3246815c24d6..37e603bf1591 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -736,7 +736,13 @@ xfs_reflink_end_cow( /* If there is a hole at end_fsb - 1 go to the previous extent */ if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) || got.br_startoff > end_fsb) { - ASSERT(idx > 0); + /* + * In case of racing, overlapping AIO writes no COW extents + * might be left by the time I/O completes for the loser of + * the race. In that case we are done. + */ + if (idx <= 0) + goto out_cancel; xfs_iext_get_extent(ifp, --idx, &got); } @@ -809,6 +815,7 @@ xfs_reflink_end_cow( out_defer: xfs_defer_cancel(&dfops); +out_cancel: xfs_trans_cancel(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); out:
If we got two AIO writes into a COW area the second one might not have any COW extents left to convert. Handle that case gracefully instead of triggering an assert or accessing beyond the bounds of the extent list. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/xfs_reflink.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)