nilfs2: call nilfs_error inside bmap routines

Some functions using nilfs bmap routines can wrongly return invalid
argument error (i.e. -EINVAL) that bmap returns as an internal code
for btree corruption.

This fixes the issue by catching and converting the internal EINVAL to
EIO and calling nilfs_error function inside bmap routines.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index 9f8a2da..bfc73d3 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -149,14 +149,9 @@
 	}
 
 	err = nilfs_palloc_get_entry_block(ifile, ino, 0, out_bh);
-	if (unlikely(err)) {
-		if (err == -EINVAL)
-			nilfs_error(sb, __func__, "ifile is broken");
-		else
-			nilfs_warning(sb, __func__,
-				      "unable to read inode: %lu",
-				      (unsigned long) ino);
-	}
+	if (unlikely(err))
+		nilfs_warning(sb, __func__, "unable to read inode: %lu",
+			      (unsigned long) ino);
 	return err;
 }