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>

1 files changed, 4 insertions, 5 deletions

diff --git a/fs/xfs/xfs_inode_fork.c b/fs/xfs/xfs_inode_fork.c
index 22c9837c5d4b..cfee14a83cfe 100644
--- 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++;
-                                }
                         }
                 }
         }