Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752562AbdLYLXN (ORCPT ); Mon, 25 Dec 2017 06:23:13 -0500 Received: from smtpbgau2.qq.com ([54.206.34.216]:45073 "EHLO smtpbgau2.qq.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752372AbdLYLXA (ORCPT ); Mon, 25 Dec 2017 06:23:00 -0500 X-QQ-mid: esmtp12t1514200975tm6e1b7y9 X-QQ-SSF: A1000000000000907H100000000000P X-QQ-FEAT: yN/dV50aaV/PWA9Yw2DS0sj4N2vd/Rtde8GWWP1rHZ3b1fvZqNOXy5O+RdTnf OYE1PmEqyS98wbKumdDeum0HXXQEUTANbzjNETquqZ4bc4mwYGm3l9s4PGcKZs7pwXGsl9V S5cfayAlGV2AIknmDjIv5AsbYmAkaYFSnL4INmP8vxC8AuoCfvoEkh3PPiyxAmC3UcEkB/W XoPQ9yjF57ZOXixFgpnPY76LmOx8Y5E8QUMWC0kEQslYIqQupFwixx917ConuWHi/RM95wb jWfyA0KYADGdYxX4ieaF8Bg+Y= X-QQ-GoodBg: 0 From: ChenGuanqiao To: hirofumi@mail.parknet.co.jp Cc: linux-kernel@vger.kernel.org, ChenGuanqiao Subject: [PATCH v4 2/2] fs: fat: add ioctl method in fat filesystem driver Date: Mon, 25 Dec 2017 19:20:20 +0800 Message-Id: <20171225112020.2267-3-chen.chenchacha@foxmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171225112020.2267-1-chen.chenchacha@foxmail.com> References: <20171225112020.2267-1-chen.chenchacha@foxmail.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtp:foxmail.com:bgforeign:bgforeign3 X-QQ-Bgrelay: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4212 Lines: 175 Signed-off-by: ChenGuanqiao --- fs/fat/file.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) diff --git a/fs/fat/file.c b/fs/fat/file.c index 4724cc9ad650..238c8e298930 100644 --- a/fs/fat/file.c +++ b/fs/fat/file.c @@ -15,11 +15,23 @@ #include #include #include +#include #include "fat.h" static long fat_fallocate(struct file *file, int mode, loff_t offset, loff_t len); +static int fat_check_volume_label(const char *label) +{ + int i; + + for (i=0; i<11; ++i) { + if (islower(label[i])) + return -EINVAL; + } + return 0; +} + static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr) { u32 attr; @@ -121,10 +133,127 @@ static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr) return put_user(sbi->vol_id, user_attr); } +static int fat_ioctl_get_volume_label(struct inode *inode, + u8 __user *vol_label) +{ + int err = 0; + struct buffer_head *bh; + struct msdos_dir_entry *de; + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + if (sbi->fat_bits == 32) + bh = sb_bread(sb, sbi->data_start); + else + bh = sb_bread(sb, sbi->dir_start); + + if (bh == NULL) { + fat_msg(sb, KERN_ERR, "unable to read root directory"); + err = -EIO; + goto out; + } + + de = (struct msdos_dir_entry *)bh->b_data; + if (copy_to_user(vol_label, de->name, MSDOS_NAME)) + err = -EFAULT; + + brelse(bh); + +out: + return err; +} + +static int fat_ioctl_set_volume_label(struct file *file, + u8 __user *vol_label) +{ + int err = 0; + u8 label[11]; + struct buffer_head *bh; + struct fat_boot_sector *b; + struct msdos_dir_entry *de; + struct inode *inode = file_inode(file); + struct super_block *sb = inode->i_sb; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + if (copy_from_user(label, vol_label, sizeof(label))) { + err = -EFAULT; + goto out; + } + + if (fat_check_volume_label(label)) { + err = -EINVAL; + goto out; + } + + err = mnt_want_write_file(file); + if (err) + goto out; + + /* Update sector's vol_label */ + bh = sb_bread(sb, 0); + if (bh == NULL) { + fat_msg(sb, KERN_ERR, + "unable to read boot sector to write volume label"); + err = -EIO; + goto out_drop_file; + } + + b = (struct fat_boot_sector *)bh->b_data; + + lock_buffer(bh); + 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(bh); + unlock_buffer(bh); + err = sync_dirty_buffer(bh); + brelse(bh); + if (err) + goto out_drop_file; + + /* updates root directory's vol_label */ + if (sbi->fat_bits == 32) + bh = sb_bread(sb, sbi->data_start); + else + bh = sb_bread(sb, sbi->dir_start); + + if (bh == NULL) { + fat_msg(sb, KERN_ERR, + "unable to read root directory to write volume label"); + err = -EIO; + goto out_drop_file; + } + + de = (struct msdos_dir_entry *)bh->b_data; + if (!(de->attr & ATTR_VOLUME)) { + err = -EFAULT; + goto out_drop_file; + } + + lock_buffer(bh); + memcpy(de->name, label, sizeof(de->name)); + mark_buffer_dirty(bh); + unlock_buffer(bh); + err = sync_dirty_buffer(bh); + brelse(bh); + if (err) + goto out_drop_file; + + memcpy(sbi->vol_label, label, sizeof(sbi->vol_label)); + +out_drop_file: + mnt_drop_write_file(file); + out: + return err; +} + long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = file_inode(filp); u32 __user *user_attr = (u32 __user *)arg; + u8 __user *user_vol_label = (u8 __user *)arg; switch (cmd) { case FAT_IOCTL_GET_ATTRIBUTES: @@ -133,6 +262,10 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return fat_ioctl_set_attributes(filp, user_attr); case FAT_IOCTL_GET_VOLUME_ID: return fat_ioctl_get_volume_id(inode, user_attr); + case FAT_IOCTL_GET_VOLUME_LABEL: + return fat_ioctl_get_volume_label(inode, user_vol_label); + case FAT_IOCTL_SET_VOLUME_LABEL: + return fat_ioctl_set_volume_label(filp, user_vol_label); default: return -ENOTTY; /* Inappropriate ioctl for device */ } -- 2.11.0