nilfs2: replace BUG_ON and BUG calls triggerable from ioctl

Pekka Enberg advised me:
> It would be nice if BUG(), BUG_ON(), and panic() calls would be
> converted to proper error handling using WARN_ON() calls. The BUG()
> call in nilfs_cpfile_delete_checkpoints(), for example, looks to be
> triggerable from user-space via the ioctl() system call.

This will follow the comment and keep them to a minimum.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 17 deletions

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 53f0d4c31cb0..6b37a2767293 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -425,7 +425,6 @@ static int nilfs_btree_node_lookup(const struct nilfs_btree *btree,
                 index++;
 
  out:
-        BUG_ON(indexp == NULL);
         *indexp = index;
 
         return s == 0;
@@ -477,8 +476,6 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
         __u64 ptr;
         int level, index, found, ret;
 
-        BUG_ON(minlevel <= NILFS_BTREE_LEVEL_DATA);
-
         node = nilfs_btree_get_root(btree);
         level = nilfs_btree_node_get_level(btree, node);
         if ((level < minlevel) ||
@@ -505,7 +502,7 @@ static int nilfs_btree_do_lookup(const struct nilfs_btree *btree,
                 if (index < nilfs_btree_node_nchildren_max(btree, node))
                         ptr = nilfs_btree_node_get_ptr(btree, node, index);
                 else {
-                        BUG_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
+                        WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN);
                         /* insert */
                         ptr = NILFS_BMAP_INVALID_PTR;
                 }
@@ -1366,7 +1363,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_btree *btree,
                 } else {
                         /* no siblings */
                         /* the only child of the root node */
-                        BUG_ON(level != nilfs_btree_height(btree) - 2);
+                        WARN_ON(level != nilfs_btree_height(btree) - 2);
                         if (nilfs_btree_node_get_nchildren(btree, node) - 1 <=
                             NILFS_BTREE_ROOT_NCHILDREN_MAX) {
                                 path[level].bp_op = nilfs_btree_shrink;
@@ -1543,7 +1540,7 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
                 break;
         case 3:
                 nchildren = nilfs_btree_node_get_nchildren(btree, root);
-                BUG_ON(nchildren > 1);
+                WARN_ON(nchildren > 1);
                 ptr = nilfs_btree_node_get_ptr(btree, root, nchildren - 1);
                 ret = nilfs_bmap_get_block(bmap, ptr, &bh);
                 if (ret < 0)
@@ -1552,7 +1549,7 @@ static int nilfs_btree_gather_data(struct nilfs_bmap *bmap,
                 break;
         default:
                 node = NULL;
-                BUG();
+                return -EINVAL;
         }
 
         nchildren = nilfs_btree_node_get_nchildren(btree, node);
@@ -1833,14 +1830,13 @@ static int nilfs_btree_prepare_propagate_v(struct nilfs_btree *btree,
         while ((++level < nilfs_btree_height(btree) - 1) &&
                !buffer_dirty(path[level].bp_bh)) {
 
-                BUG_ON(buffer_nilfs_volatile(path[level].bp_bh));
+                WARN_ON(buffer_nilfs_volatile(path[level].bp_bh));
                 ret = nilfs_btree_prepare_update_v(btree, path, level);
                 if (ret < 0)
                         goto out;
         }
 
         /* success */
-        BUG_ON(maxlevelp == NULL);
         *maxlevelp = level - 1;
         return 0;
 
@@ -1909,7 +1905,7 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
         __u64 key;
         int level, ret;
 
-        BUG_ON(!buffer_dirty(bh));
+        WARN_ON(!buffer_dirty(bh));
 
         btree = (struct nilfs_btree *)bmap;
         path = nilfs_btree_alloc_path(btree);
@@ -1928,12 +1924,9 @@ static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
 
         ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
         if (ret < 0) {
-                /* BUG_ON(ret == -ENOENT); */
-                if (ret == -ENOENT) {
+                if (unlikely(ret == -ENOENT))
                         printk(KERN_CRIT "%s: key = %llu, level == %d\n",
                                __func__, (unsigned long long)key, level);
-                        BUG();
-                }
                 goto out;
         }
 
@@ -2117,7 +2110,7 @@ static int nilfs_btree_assign(struct nilfs_bmap *bmap,
 
         ret = nilfs_btree_do_lookup(btree, path, key, NULL, level + 1);
         if (ret < 0) {
-                BUG_ON(ret == -ENOENT);
+                WARN_ON(ret == -ENOENT);
                 goto out;
         }
 
@@ -2175,12 +2168,12 @@ static int nilfs_btree_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 
         ret = nilfs_btree_do_lookup(btree, path, key, &ptr, level + 1);
         if (ret < 0) {
-                BUG_ON(ret == -ENOENT);
+                WARN_ON(ret == -ENOENT);
                 goto out;
         }
         ret = nilfs_bmap_get_block(&btree->bt_bmap, ptr, &bh);
         if (ret < 0) {
-                BUG_ON(ret == -ENOENT);
+                WARN_ON(ret == -ENOENT);
                 goto out;
         }