From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:46201 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751056AbcBMC4l (ORCPT ); Fri, 12 Feb 2016 21:56:41 -0500 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim Subject: [PATCH 3/3] f2fs: avoid garbage lenghs in dentries Date: Fri, 12 Feb 2016 18:56:35 -0800 Message-Id: <1455332195-76333-3-git-send-email-jaegeuk@kernel.org> In-Reply-To: <1455332195-76333-1-git-send-email-jaegeuk@kernel.org> References: <1455332195-76333-1-git-send-email-jaegeuk@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: This patch fixes to eliminate garbage name lengths in dentries in order to provide correct answers of readdir. For example, if a valid dentry consists of: bitmap : 1 1 1 1 len : 32 0 x 0, readdir can start with second bit_pos having len = 0. Or, it can start with third bit_pos having garbage. In both of cases, we should avoid to try filling dentries. So, this patch not only removes any garbage length, but also avoid entering zero length case in readdir. Signed-off-by: Jaegeuk Kim --- fs/f2fs/dir.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 8950fc3..ca41b2a 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -511,8 +511,12 @@ void f2fs_update_dentry(nid_t ino, umode_t mode, struct f2fs_dentry_ptr *d, memcpy(d->filename[bit_pos], name->name, name->len); de->ino = cpu_to_le32(ino); set_de_type(de, mode); - for (i = 0; i < slots; i++) + for (i = 0; i < slots; i++) { test_and_set_bit_le(bit_pos + i, (void *)d->bitmap); + /* avoid wrong garbage data for readdir */ + if (i) + (de + i)->name_len = 0; + } } /* @@ -792,6 +796,12 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, break; de = &d->dentry[bit_pos]; + if (de->name_len == 0) { + bit_pos++; + ctx->pos = start_pos + bit_pos; + continue; + } + if (de->file_type < F2FS_FT_MAX) d_type = f2fs_filetype_table[de->file_type]; else -- 2.6.3