[mirror_ubuntu-zesty-kernel.git] / fs / reiserfs / ioctl.c

/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <linux/fs.h>
#include <linux/reiserfs_fs.h>
#include <linux/time.h>
#include <asm/uaccess.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>

static int reiserfs_unpack(struct inode *inode, struct file *filp);

/*
** reiserfs_ioctl - handler for ioctl for inode
** supported commands:
**  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
**                           and prevent packing file (argument arg has to be non-zero)
**  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
**  3) That's all for a while ...
*/
int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
		   unsigned long arg)
{
	unsigned int flags;

	switch (cmd) {
	case REISERFS_IOC_UNPACK:
		if (S_ISREG(inode->i_mode)) {
			if (arg)
				return reiserfs_unpack(inode, filp);
			else
				return 0;
		} else
			return -ENOTTY;
		/* following two cases are taken from fs/ext2/ioctl.c by Remy
		   Card (card@masi.ibp.fr) */
	case REISERFS_IOC_GETFLAGS:
		if (!reiserfs_attrs(inode->i_sb))
			return -ENOTTY;

		flags = REISERFS_I(inode)->i_attrs;
		i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
		return put_user(flags, (int __user *)arg);
	case REISERFS_IOC_SETFLAGS:{
			if (!reiserfs_attrs(inode->i_sb))
				return -ENOTTY;

			if (IS_RDONLY(inode))
				return -EROFS;

			if ((current->fsuid != inode->i_uid)
			    && !capable(CAP_FOWNER))
				return -EPERM;

			if (get_user(flags, (int __user *)arg))
				return -EFAULT;

			if (((flags ^ REISERFS_I(inode)->
			      i_attrs) & (REISERFS_IMMUTABLE_FL |
					  REISERFS_APPEND_FL))
			    && !capable(CAP_LINUX_IMMUTABLE))
				return -EPERM;

			if ((flags & REISERFS_NOTAIL_FL) &&
			    S_ISREG(inode->i_mode)) {
				int result;

				result = reiserfs_unpack(inode, filp);
				if (result)
					return result;
			}
			sd_attrs_to_i_attrs(flags, inode);
			REISERFS_I(inode)->i_attrs = flags;
			inode->i_ctime = CURRENT_TIME_SEC;
			mark_inode_dirty(inode);
			return 0;
		}
	case REISERFS_IOC_GETVERSION:
		return put_user(inode->i_generation, (int __user *)arg);
	case REISERFS_IOC_SETVERSION:
		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
			return -EPERM;
		if (IS_RDONLY(inode))
			return -EROFS;
		if (get_user(inode->i_generation, (int __user *)arg))
			return -EFAULT;
		inode->i_ctime = CURRENT_TIME_SEC;
		mark_inode_dirty(inode);
		return 0;
	default:
		return -ENOTTY;
	}
}

/*
** reiserfs_unpack
** Function try to convert tail from direct item into indirect.
** It set up nopack attribute in the REISERFS_I(inode)->nopack
*/
static int reiserfs_unpack(struct inode *inode, struct file *filp)
{
	int retval = 0;
	int index;
	struct page *page;
	struct address_space *mapping;
	unsigned long write_from;
	unsigned long blocksize = inode->i_sb->s_blocksize;

	if (inode->i_size == 0) {
		REISERFS_I(inode)->i_flags |= i_nopack_mask;
		return 0;
	}
	/* ioctl already done */
	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
		return 0;
	}
	reiserfs_write_lock(inode->i_sb);

	/* we need to make sure nobody is changing the file size beneath
	 ** us
	 */
	mutex_lock(&inode->i_mutex);

	write_from = inode->i_size & (blocksize - 1);
	/* if we are on a block boundary, we are already unpacked.  */
	if (write_from == 0) {
		REISERFS_I(inode)->i_flags |= i_nopack_mask;
		goto out;
	}

	/* we unpack by finding the page with the tail, and calling
	 ** reiserfs_prepare_write on that page.  This will force a 
	 ** reiserfs_get_block to unpack the tail for us.
	 */
	index = inode->i_size >> PAGE_CACHE_SHIFT;
	mapping = inode->i_mapping;
	page = grab_cache_page(mapping, index);
	retval = -ENOMEM;
	if (!page) {
		goto out;
	}
	retval =
	    mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
	if (retval)
		goto out_unlock;

	/* conversion can change page contents, must flush */
	flush_dcache_page(page);
	retval =
	    mapping->a_ops->commit_write(NULL, page, write_from, write_from);
	REISERFS_I(inode)->i_flags |= i_nopack_mask;

      out_unlock:
	unlock_page(page);
	page_cache_release(page);

      out:
	mutex_unlock(&inode->i_mutex);
	reiserfs_write_unlock(inode->i_sb);
	return retval;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
	3	*/
	4
	5	#include <linux/fs.h>
	6	#include <linux/reiserfs_fs.h>
	7	#include <linux/time.h>
	8	#include <asm/uaccess.h>
	9	#include <linux/pagemap.h>
	10	#include <linux/smp_lock.h>
	11
bd4c625c	12	static int reiserfs_unpack(struct inode inode, struct file filp);
1da177e4 LT	13
	14	/*
	15	** reiserfs_ioctl - handler for ioctl for inode
	16	** supported commands:
	17	** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
	18	** and prevent packing file (argument arg has to be non-zero)
	19	** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
	20	** 3) That's all for a while ...
	21	*/
bd4c625c LT	22	int reiserfs_ioctl(struct inode inode, struct file filp, unsigned int cmd,
bd4c625c LT	23	unsigned long arg)
1da177e4 LT	24	{
	25	unsigned int flags;
	26
	27	switch (cmd) {
bd4c625c LT	28	case REISERFS_IOC_UNPACK:
	29	if (S_ISREG(inode->i_mode)) {
	30	if (arg)
	31	return reiserfs_unpack(inode, filp);
1da177e4 LT	32	else
	33	return 0;
	34	} else
	35	return -ENOTTY;
bd4c625c LT	36	/* following two cases are taken from fs/ext2/ioctl.c by Remy
bd4c625c LT	37	Card (card@masi.ibp.fr) */
1da177e4	38	case REISERFS_IOC_GETFLAGS:
bd4c625c	39	if (!reiserfs_attrs(inode->i_sb))
869eb76e JM	40	return -ENOTTY;
869eb76e JM	41
bd4c625c LT	42	flags = REISERFS_I(inode)->i_attrs;
	43	i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
	44	return put_user(flags, (int __user *)arg);
	45	case REISERFS_IOC_SETFLAGS:{
	46	if (!reiserfs_attrs(inode->i_sb))
	47	return -ENOTTY;
869eb76e	48
bd4c625c LT	49	if (IS_RDONLY(inode))
bd4c625c LT	50	return -EROFS;
1da177e4	51
bd4c625c LT	52	if ((current->fsuid != inode->i_uid)
	53	&& !capable(CAP_FOWNER))
	54	return -EPERM;
1da177e4	55
bd4c625c LT	56	if (get_user(flags, (int __user *)arg))
bd4c625c LT	57	return -EFAULT;
1da177e4	58
bd4c625c LT	59	if (((flags ^ REISERFS_I(inode)->
	60	i_attrs) & (REISERFS_IMMUTABLE_FL \|
	61	REISERFS_APPEND_FL))
	62	&& !capable(CAP_LINUX_IMMUTABLE))
	63	return -EPERM;
	64
	65	if ((flags & REISERFS_NOTAIL_FL) &&
	66	S_ISREG(inode->i_mode)) {
1da177e4 LT	67	int result;
1da177e4 LT	68
bd4c625c LT	69	result = reiserfs_unpack(inode, filp);
bd4c625c LT	70	if (result)
1da177e4	71	return result;
bd4c625c LT	72	}
	73	sd_attrs_to_i_attrs(flags, inode);
	74	REISERFS_I(inode)->i_attrs = flags;
	75	inode->i_ctime = CURRENT_TIME_SEC;
	76	mark_inode_dirty(inode);
	77	return 0;
1da177e4	78	}
1da177e4	79	case REISERFS_IOC_GETVERSION:
bd4c625c	80	return put_user(inode->i_generation, (int __user *)arg);
1da177e4 LT	81	case REISERFS_IOC_SETVERSION:
	82	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
	83	return -EPERM;
	84	if (IS_RDONLY(inode))
	85	return -EROFS;
bd4c625c LT	86	if (get_user(inode->i_generation, (int __user *)arg))
bd4c625c LT	87	return -EFAULT;
1da177e4 LT	88	inode->i_ctime = CURRENT_TIME_SEC;
	89	mark_inode_dirty(inode);
	90	return 0;
	91	default:
	92	return -ENOTTY;
	93	}
	94	}
	95
	96	/*
	97	** reiserfs_unpack
	98	** Function try to convert tail from direct item into indirect.
	99	** It set up nopack attribute in the REISERFS_I(inode)->nopack
	100	*/
bd4c625c	101	static int reiserfs_unpack(struct inode inode, struct file filp)
1da177e4	102	{
bd4c625c LT	103	int retval = 0;
	104	int index;
	105	struct page *page;
	106	struct address_space *mapping;
	107	unsigned long write_from;
	108	unsigned long blocksize = inode->i_sb->s_blocksize;
	109
	110	if (inode->i_size == 0) {
	111	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
	112	return 0;
	113	}
	114	/* ioctl already done */
	115	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
	116	return 0;
	117	}
	118	reiserfs_write_lock(inode->i_sb);
	119
	120	/* we need to make sure nobody is changing the file size beneath
	121	** us
	122	*/
1b1dcc1b	123	mutex_lock(&inode->i_mutex);
bd4c625c LT	124
	125	write_from = inode->i_size & (blocksize - 1);
	126	/* if we are on a block boundary, we are already unpacked. */
	127	if (write_from == 0) {
	128	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
	129	goto out;
	130	}
	131
	132	/* we unpack by finding the page with the tail, and calling
	133	** reiserfs_prepare_write on that page. This will force a
	134	** reiserfs_get_block to unpack the tail for us.
	135	*/
	136	index = inode->i_size >> PAGE_CACHE_SHIFT;
	137	mapping = inode->i_mapping;
	138	page = grab_cache_page(mapping, index);
	139	retval = -ENOMEM;
	140	if (!page) {
	141	goto out;
	142	}
	143	retval =
	144	mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
	145	if (retval)
	146	goto out_unlock;
	147
	148	/* conversion can change page contents, must flush */
	149	flush_dcache_page(page);
	150	retval =
	151	mapping->a_ops->commit_write(NULL, page, write_from, write_from);
1da177e4	152	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
bd4c625c LT	153
	154	out_unlock:
	155	unlock_page(page);
	156	page_cache_release(page);
	157
	158	out:
1b1dcc1b	159	mutex_unlock(&inode->i_mutex);
bd4c625c LT	160	reiserfs_write_unlock(inode->i_sb);
bd4c625c LT	161	return retval;
1da177e4	162	}