xfs: upgrade the extent counters in xfs_reflink_end_cow_extent later

Defer the extent counter size upgrade until we know we're going to
modify the extent mapping.  This also defers dirtying the transaction
and will allow us safely back out later in the function in later
changes.

Fixes: 4f86bb4b66c9 ("xfs: Conditionally upgrade existing inodes to use large extent counters")
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 24761e89ce9aecad9111d1cfd76d4b6f6062a8cb..93f775c13b6648ec79beb8c9a8f35e39a0396968 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -732,14 +732,6 @@ xfs_reflink_end_cow_extent(
        xfs_ilock(ip, XFS_ILOCK_EXCL);
        xfs_trans_ijoin(tp, ip, 0);
 
-       error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
-                       XFS_IEXT_REFLINK_END_COW_CNT);
-       if (error == -EFBIG)
-               error = xfs_iext_count_upgrade(tp, ip,
-                               XFS_IEXT_REFLINK_END_COW_CNT);
-       if (error)
-               goto out_cancel;
-
        /*
         * 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
@@ -768,6 +760,14 @@ xfs_reflink_end_cow_extent(
        del = got;
        xfs_trim_extent(&del, *offset_fsb, end_fsb - *offset_fsb);
 
+       error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+                       XFS_IEXT_REFLINK_END_COW_CNT);
+       if (error == -EFBIG)
+               error = xfs_iext_count_upgrade(tp, ip,
+                               XFS_IEXT_REFLINK_END_COW_CNT);
+       if (error)
+               goto out_cancel;
+
        /* Grab the corresponding mapping in the data fork. */
        nmaps = 1;
        error = xfs_bmapi_read(ip, del.br_startoff, del.br_blockcount, &data,