From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752001AbeA2NCs (ORCPT ); Mon, 29 Jan 2018 08:02:48 -0500 Received: from mail.parknet.co.jp ([210.171.160.6]:44661 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751822AbeA2NCr (ORCPT ); Mon, 29 Jan 2018 08:02:47 -0500 From: OGAWA Hirofumi To: ChenGuanqiao Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] fs: fat: add ioctl method in fat filesystem driver References: <20180117104355.889-1-chen.chenchacha@foxmail.com> <20180117104355.889-4-chen.chenchacha@foxmail.com> Date: Mon, 29 Jan 2018 22:02:43 +0900 In-Reply-To: <20180117104355.889-4-chen.chenchacha@foxmail.com> (ChenGuanqiao's message of "Wed, 17 Jan 2018 18:43:55 +0800") Message-ID: <87r2q8n7gs.fsf@mail.parknet.co.jp> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ChenGuanqiao writes: > +static int fat_check_d_characters(char *label, unsigned long len) > +{ > + int i; > + > + for (i = 0; i < len; ++i) { > + switch (label[i]) { > + case 'a' ... 'z': > + label[i] = __toupper(label[i]); > + case 'A' ... 'Z': > + case '0' ... '9': > + case '_': > + case 0x20: > + continue; > + default: > + return -EINVAL; > + } Same question with previous though, what windows do if label = "a b c"? (this is including space other than end of name or extension.) > + } > + > + return 0; > +} > +static int fat_ioctl_set_volume_label(struct file *file, > + u8 __user *vol_label) > +{ > + int err = 0; > + u8 label[MSDOS_NAME]; > + struct timespec ts; > + struct buffer_head *boot_bh; > + struct buffer_head *vol_bh; > + struct msdos_dir_entry *de; > + struct fat_boot_sector *b; > + struct inode *inode = file_inode(file); > + struct super_block *sb = inode->i_sb; > + struct msdos_sb_info *sbi = MSDOS_SB(sb); > + [...] > + err = mnt_want_write_file(file); > + if (err) > + goto out; > + > + down_write(&sb->s_umount); Looks like inode_lock() for rootdir is gone. It is necessary to traverse+modify. > + /* Updates root directory's vol_label */ > + err = fat_get_volume_label_entry(inode, &vol_bh, &de); > + ts = current_time(inode); > + if (err) { > + /* Create volume label entry */ > + err = fat_add_volume_label_entry(inode, label, &ts); > + if (err) > + goto out_vol_brelse; > + } else { > + /* Write to root directory */ > + memcpy(de->name, label, sizeof(de->name)); > + inode->i_ctime = inode->i_mtime = inode->i_atime = ts; > + > + mark_buffer_dirty(vol_bh); > + } > + > + /* Update sector's vol_label */ > + boot_bh = sb_bread(sb, 0); > + if (boot_bh == NULL) { > + fat_msg(sb, KERN_ERR, > + "unable to read boot sector to write volume label"); > + err = -EIO; > + goto out_boot_brelse; > + } > + > + b = (struct fat_boot_sector *)boot_bh->b_data; > + if (sbi->fat_bits == 32) > + memcpy(b->fat32.vol_label, label, sizeof(label)); > + else > + memcpy(b->fat16.vol_label, label, sizeof(label)); > + > + mark_buffer_dirty(boot_bh); > + > + /* Synchronize the data together */ > + err = sync_dirty_buffer(boot_bh); > + if (err) > + goto out_boot_brelse; -- OGAWA Hirofumi