Messages in this thread | | | From | OGAWA Hirofumi <> | Subject | Re: [PATCH 3/3] fs: fat: add ioctl method in fat filesystem driver | Date | Tue, 30 Jan 2018 20:23:03 +0900 |
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chenchacha <chen.chenchacha@foxmail.com> writes:
> On 01/29/2018 09:02 PM, OGAWA Hirofumi wrote: >> ChenGuanqiao <chen.chenchacha@foxmail.com> 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.) > In win7, the volume label will be capitalized, and leaving spaces. > Or, you mean I need to fill the rest of the space with "0x20"?
I see. However, what win7 stored, BTW? It was "A B C ", or anything other?
>>> +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); >>> + >> [...] > I need remove "struct msdos_sb_info *sbi"?
If you didn't use sbi anymore, you should remove.
>>> + 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. > Is it wrong for me to use the inode_lock() in patch v7? I need to lock > inode here, and turn off immediately after
inode_lock() is necessary to protect race with other dir operations.
I asked at v7, locking order to prevent the AB locking order bug.
I.e. mnt_want_write_file => down_write => inode_lock() vs down_write => mnt_want_write_file => inode_lock()
Which is right one?
> mark_buffer_dirty(vol_bh)?
What is this asking? -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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