[PATCH] nilfs2: switch WARN_ONs to warning output in nilfs_sufile_do_free()

[Ryusuke Konishi <konishi.ryusuke@gmail.com>]

nilfs_sufile_do_free(), which is called when log write fails or during
GC, uses WARN_ONs to check for abnormal status of metadata.  In the
former case, these WARN_ONs will not be fired, but in the latter case
they don't "never-happen".  It is possible to trigger these by
intentionally modifying the userland GC library to release segments
that are not in the expected state.

So, replace them with warning output using the dedicated macro
nilfs_warn().

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
---
Andrew, please add this to the queue for the next merge window.  This
replaces two potentially triggered WARN_ONs with ones that use a warning
output macro.

Thanks,
Ryusuke Konishi

fs/nilfs2/sufile.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 58ca7c936393..0a8119456c21 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -471,10 +471,15 @@ void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 		kunmap_atomic(kaddr);
 		return;
 	}
-	WARN_ON(nilfs_segment_usage_error(su));
-	WARN_ON(!nilfs_segment_usage_dirty(su));
+	if (unlikely(nilfs_segment_usage_error(su)))
+		nilfs_warn(sufile->i_sb, "free segment %llu marked in error",
+			   (unsigned long long)segnum);
 
 	sudirty = nilfs_segment_usage_dirty(su);
+	if (unlikely(!sudirty))
+		nilfs_warn(sufile->i_sb, "free unallocated segment %llu",
+			   (unsigned long long)segnum);
+
 	nilfs_segment_usage_set_clean(su);
 	kunmap_atomic(kaddr);
 	mark_buffer_dirty(su_bh);
-- 
2.34.1