linux-ext4 - Re: [PATCH 1/3] Add ioctl FITRIM.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 04 Aug 2010 18:57:48 +0400
From:	Dmitry Monakhov <dmonakhov@...nvz.org>
To:	Lukas Czerner <lczerner@...hat.com>
Cc:	linux-ext4@...r.kernel.org, jmoyer@...hat.com, rwheeler@...hat.com,
	eshishki@...hat.com, sandeen@...hat.com, jack@...e.cz,
	tytso@....edu
Subject: Re: [PATCH 1/3] Add ioctl FITRIM.

Lukas Czerner <lczerner@...hat.com> writes:

> Adds an filesystem independent ioctl to allow implementation of file
> system batched discard support.
>
> Signed-off-by: Lukas Czerner <lczerner@...hat.com>
> ---
>  fs/ioctl.c         |   31 +++++++++++++++++++++++++++++++
>  include/linux/fs.h |    2 ++
>  2 files changed, 33 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index 2d140a7..6c01c3c 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -540,6 +540,33 @@ static int ioctl_fsthaw(struct file *filp)
>  	return thaw_super(sb);
>  }
>  
> +static int ioctl_fstrim(struct file *filp, unsigned long arg)
BTW why do we have to trim fs in one shot ?
IMHO it is much suitable to provide start,len parameters as we 
do in most functions(truncate, bdevdiscard, getdents).
It allow userspace caller to implement a fancy looking progress bars.
> +{
> +	struct super_block *sb = filp->f_path.dentry->d_inode->i_sb;
> +	unsigned int minlen;
> +	int err;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +
> +	/* If filesystem doesn't support trim feature, return. */
> +	if (sb->s_op->trim_fs == NULL)
> +		return -EOPNOTSUPP;
> +
> +	/* If a blockdevice-backed filesystem isn't specified, return EINVAL. */
> +	if (sb->s_bdev == NULL)
> +		return -EINVAL;
> +
> +	err = get_user(minlen, (unsigned int __user *) arg);
> +	if (err)
> +		return err;
> +
> +	err = sb->s_op->trim_fs(minlen, sb);
> +	if (err)
> +		return err;
> +	return 0;
> +}
> +
>  /*
>   * When you add any new common ioctls to the switches above and below
>   * please update compat_sys_ioctl() too.
> @@ -590,6 +617,10 @@ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
>  		error = ioctl_fsthaw(filp);
>  		break;
>  
> +	case FITRIM:
> +		error = ioctl_fstrim(filp, arg);
> +		break;
> +
>  	case FS_IOC_FIEMAP:
>  		return ioctl_fiemap(filp, arg);
>  
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 68ca1b0..01632e4 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -315,6 +315,7 @@ struct inodes_stat_t {
>  #define FIGETBSZ   _IO(0x00,2)	/* get the block size used for bmap */
>  #define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
>  #define FITHAW		_IOWR('X', 120, int)	/* Thaw */
> +#define FITRIM		_IOWR('X', 121, int)	/* Trim */
>  
>  #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
>  #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
> @@ -1580,6 +1581,7 @@ struct super_operations {
>  	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
>  #endif
>  	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
> +	int (*trim_fs) (unsigned int, struct super_block *);
>  };
>  
>  /*
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html