Messages in this thread | | | From | OGAWA Hirofumi <> | Subject | Re: [PATCH RFC] Add FAT_IOCTL_GET_VOLUME_ID | Date | Mon, 01 Jul 2013 21:00:54 +0900 |
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bintian.wang@linaro.org writes:
> From: Mike Lockwood <lockwood@android.com> > > Adds vfat ioctl command FAT_IOCTL_GET_VOLUME_ID, with this command > we can get the vfat volume ID using following code: > > ioctl(fd, FAT_IOCTL_GET_VOLUME_ID, &volume_ID) > > This patch is a modified version of the android kernel patch by Mike Lockwood, > the original patch makes the return value of ioctl() as the volume ID, > Dmitry Pervushin noticed some volume IDs abiguous with error returns: > for example, if volume id is set to "0xFFFFFDAD", that matches -ENOIOCTLCMD, > we get a wrong volume ID "0xFFFFFFFF" from the user space. > > This patch fixes above bug by adding a parameter to ioctl to get the correct > volume ID.
Personally, I have no objection to do this small one in kernel though. Please add use case of android to changelog, it would help to understand.
> +static unsigned int fat_ioctl_volume_id(struct inode *inode) > +{ > + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); > + return sbi->vol_id; > +} > + > long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct inode *inode = file_inode(filp); > @@ -124,6 +130,8 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return fat_ioctl_get_attributes(inode, user_attr); > case FAT_IOCTL_SET_ATTRIBUTES: > return fat_ioctl_set_attributes(filp, user_attr); > + case FAT_IOCTL_GET_VOLUME_ID: > + return put_user(fat_ioctl_volume_id(inode), user_attr); > default: > return -ENOTTY; /* Inappropriate ioctl for device */ > }
Please push put_user() down into fat_ioctl_volume_id() like others. So, generic_ioctl() itself can forget about the detail of each ioctl.
Thanks. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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