xfs: delalloc -> unwritten COW fork allocation can go wrong

[sfrench/cifs-2.6.git] / fs / xfs / libxfs / xfs_bmap.c

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 74d7228e755b3ade097457c0ae68e07e252e67a4..19e921d1586f273f7f234d0c32a8982683821f69 100644 (file)
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1694,10 +1694,13 @@ xfs_bmap_add_extent_delay_real(
        case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
                /*
                 * Filling in all of a previously delayed allocation extent.
-                * The right neighbor is contiguous, the left is not.
+                * The right neighbor is contiguous, the left is not. Take care
+                * with delay -> unwritten extent allocation here because the
+                * delalloc record we are overwriting is always written.
                 */
                PREV.br_startblock = new->br_startblock;
                PREV.br_blockcount += RIGHT.br_blockcount;
+               PREV.br_state = new->br_state;
 
                xfs_iext_next(ifp, &bma->icur);
                xfs_iext_remove(bma->ip, &bma->icur, state);