ufs_trunc_branch(): never call with offsets != NULL && depth2 == 0

For calls in __ufs_truncate_blocks() it's just a matter of not
incrementing offsets[0] and not making that call - immediately
following loop will be executed one extra time and we'll be just
fine.  For recursive call in ufs_trunc_branch() itself, just
assing NULL to offsets if we would be about to make such call.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 285eacd..9e409c1 100644 (file)
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -1075,7 +1075,7 @@ static void ufs_trunc_branch(struct inode *inode, unsigned *offsets, int depth2,
        struct ufs_inode_info *ufsi = UFS_I(inode);
        struct ufs_buffer_head *ubh;
        u64 tmp;
-       bool free_it = !offsets || !depth2;
+       bool free_it = !offsets;
        unsigned from = offsets ? *offsets++ : 0;
        unsigned i;
 
@@ -1091,9 +1091,11 @@ static void ufs_trunc_branch(struct inode *inode, unsigned *offsets, int depth2,
        }
 
        if (--depth) {
+               if (!--depth2)
+                       offsets = NULL;
                for (i = from ; i < uspi->s_apb ; i++, offsets = NULL) {
                        void *ind = ubh_get_data_ptr(uspi, ubh, i);
-                       ufs_trunc_branch(inode, offsets, depth2 - 1, depth, ind);
+                       ufs_trunc_branch(inode, offsets, depth2, depth, ind);
                        ubh_mark_buffer_dirty(ubh);
                }
        } else {
@@ -1237,7 +1239,8 @@ static void __ufs_truncate_blocks(struct inode *inode)
                ufs_trunc_direct(inode);
                offsets[0] = UFS_IND_BLOCK;
        } else {
-               ufs_trunc_branch(inode, offsets + 1, depth2, depth - 1,
+               if (depth2)
+                       ufs_trunc_branch(inode, offsets + 1, depth2, depth - 1,
                           ufs_get_direct_data_ptr(uspi, ufsi, offsets[0]++));
        }
        for (i = offsets[0]; i <= UFS_TIND_BLOCK; i++) {