From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: [PATCH] vfs: Return EINVAL for default SEEK_HOLE, SEEK_DATA implementation Date: Fri, 3 Jan 2014 11:35:26 +0100 Message-ID: <1388745326-13226-1-git-send-email-jack@suse.cz> Cc: Josef Bacik , Theodore Ts'o , linux-fsdevel@vger.kernel.org, Jeff Liu , Jan Kara To: Al Viro Return-path: Received: from cantor2.suse.de ([195.135.220.15]:56360 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750837AbaACKff (ORCPT ); Fri, 3 Jan 2014 05:35:35 -0500 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Generic implementation of SEEK_HOLE & SEEK_DATA in generic_file_llseek_size() and default_llseek() behaved as if everything within i_size is data and everything beyond i_size is a hole. That makes sense at the first sight (and definitely is a valid implementation of the spec) but at the second sight it isn't very useful. If anyone bothers with looking for holes / data, he should be better told we don't really know so that he can fall back to his chosen backup strategy (think of e.g. cp(1)). This is a userspace API change however the kernel interface is there only for two years so hopefully userspace is still prepared to handle EINVAL return value. Signed-off-by: Jan Kara --- fs/read_write.c | 38 ++------------------------------------ 1 file changed, 2 insertions(+), 36 deletions(-) So given our discussion in http://www.spinics.net/lists/linux-fsdevel/msg71363.html I've decided to throw this patch in. Al, what do you think about it? diff --git a/fs/read_write.c b/fs/read_write.c index 58e440df1bc6..40a324f1d93b 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -111,22 +111,8 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, spin_unlock(&file->f_lock); return offset; case SEEK_DATA: - /* - * In the generic case the entire file is data, so as long as - * offset isn't at the end of the file then the offset is data. - */ - if (offset >= eof) - return -ENXIO; - break; case SEEK_HOLE: - /* - * There is a virtual hole at the end of the file, so as long as - * offset isn't i_size or larger, return i_size. - */ - if (offset >= eof) - return -ENXIO; - offset = eof; - break; + return -EINVAL; } return vfs_setpos(file, offset, maxsize); @@ -214,28 +200,8 @@ loff_t default_llseek(struct file *file, loff_t offset, int whence) offset += file->f_pos; break; case SEEK_DATA: - /* - * In the generic case the entire file is data, so as - * long as offset isn't at the end of the file then the - * offset is data. - */ - if (offset >= inode->i_size) { - retval = -ENXIO; - goto out; - } - break; case SEEK_HOLE: - /* - * There is a virtual hole at the end of the file, so - * as long as offset isn't i_size or larger, return - * i_size. - */ - if (offset >= inode->i_size) { - retval = -ENXIO; - goto out; - } - offset = inode->i_size; - break; + return -EINVAL; } retval = -EINVAL; if (offset >= 0 || unsigned_offsets(file)) { -- 1.8.1.4