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, 4 insertions, 6 deletions

diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index 7b18be8cd47a..1bfbba9c0e9a 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -417,7 +417,7 @@ repeat:
                 dpage = find_lock_page(dmap, offset);
                 if (dpage) {
                         /* override existing page on the destination cache */
-                        BUG_ON(PageDirty(dpage));
+                        WARN_ON(PageDirty(dpage));
                         nilfs_copy_page(dpage, page, 0);
                         unlock_page(dpage);
                         page_cache_release(dpage);
@@ -427,17 +427,15 @@ repeat:
                         /* move the page to the destination cache */
                         spin_lock_irq(&smap->tree_lock);
                         page2 = radix_tree_delete(&smap->page_tree, offset);
-                        if (unlikely(page2 != page))
-                                NILFS_PAGE_BUG(page, "page removal failed "
-                                               "(offset=%lu, page2=%p)",
-                                               offset, page2);
+                        WARN_ON(page2 != page);
+
                         smap->nrpages--;
                         spin_unlock_irq(&smap->tree_lock);
 
                         spin_lock_irq(&dmap->tree_lock);
                         err = radix_tree_insert(&dmap->page_tree, offset, page);
                         if (unlikely(err < 0)) {
-                                BUG_ON(err == -EEXIST);
+                                WARN_ON(err == -EEXIST);
                                 page->mapping = NULL;
                                 page_cache_release(page); /* for cache */
                         } else {