xfs: fix the extent count when allocating an new indirection array entry

At xfs_iext_add(), if extent(s) are being appended to the last page in
the indirection array and the new extent(s) don't fit in the page, the
number of extents(erp->er_extcount) in a new allocated entry should be
the minimum value between count and XFS_LINEAR_EXTS, instead of count.

For now, there is no existing test case can demonstrates a problem with
the er_extcount being set incorrectly here, but it obviously like a bug.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_inode_fork.c b/fs/xfs/xfs_inode_fork.c
index 22c9837c5d4beb680514213369aa0722d189503f..cfee14a83cfe601d90bdc6732cc608746aaf3e03 100644 (file)
--- a/fs/xfs/xfs_inode_fork.c
+++ b/fs/xfs/xfs_inode_fork.c
@@ -1021,15 +1021,14 @@ xfs_iext_add(
                 * the next index needed in the indirection array.
                 */
                else {
-                       int     count = ext_diff;
+                       uint    count = ext_diff;
 
                        while (count) {
                                erp = xfs_iext_irec_new(ifp, erp_idx);
-                               erp->er_extcount = count;
-                               count -= MIN(count, (int)XFS_LINEAR_EXTS);
-                               if (count) {
+                               erp->er_extcount = min(count, XFS_LINEAR_EXTS);
+                               count -= erp->er_extcount;
+                               if (count)
                                        erp_idx++;
-                               }
                        }
                }
        }