[deliverable/linux.git] / fs / reiserfs / ioctl.c

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

#include <linux/capability.h>
#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;
	}

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

	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
16f7e0fe	5	#include <linux/capability.h>
1da177e4 LT	6	#include <linux/fs.h>
	7	#include <linux/reiserfs_fs.h>
	8	#include <linux/time.h>
	9	#include <asm/uaccess.h>
	10	#include <linux/pagemap.h>
	11	#include <linux/smp_lock.h>
	12
bd4c625c	13	static int reiserfs_unpack(struct inode inode, struct file filp);
1da177e4 LT	14
	15	/*
	16	** reiserfs_ioctl - handler for ioctl for inode
	17	** supported commands:
	18	** 1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
	19	** and prevent packing file (argument arg has to be non-zero)
	20	** 2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
	21	** 3) That's all for a while ...
	22	*/
bd4c625c LT	23	int reiserfs_ioctl(struct inode inode, struct file filp, unsigned int cmd,
bd4c625c LT	24	unsigned long arg)
1da177e4 LT	25	{
	26	unsigned int flags;
	27
	28	switch (cmd) {
bd4c625c LT	29	case REISERFS_IOC_UNPACK:
	30	if (S_ISREG(inode->i_mode)) {
	31	if (arg)
	32	return reiserfs_unpack(inode, filp);
1da177e4 LT	33	else
	34	return 0;
	35	} else
	36	return -ENOTTY;
bd4c625c LT	37	/* following two cases are taken from fs/ext2/ioctl.c by Remy
bd4c625c LT	38	Card (card@masi.ibp.fr) */
1da177e4	39	case REISERFS_IOC_GETFLAGS:
bd4c625c	40	if (!reiserfs_attrs(inode->i_sb))
869eb76e JM	41	return -ENOTTY;
869eb76e JM	42
bd4c625c LT	43	flags = REISERFS_I(inode)->i_attrs;
	44	i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
	45	return put_user(flags, (int __user *)arg);
	46	case REISERFS_IOC_SETFLAGS:{
	47	if (!reiserfs_attrs(inode->i_sb))
	48	return -ENOTTY;
869eb76e	49
bd4c625c LT	50	if (IS_RDONLY(inode))
bd4c625c LT	51	return -EROFS;
1da177e4	52
bd4c625c LT	53	if ((current->fsuid != inode->i_uid)
	54	&& !capable(CAP_FOWNER))
	55	return -EPERM;
1da177e4	56
bd4c625c LT	57	if (get_user(flags, (int __user *)arg))
bd4c625c LT	58	return -EFAULT;
1da177e4	59
bd4c625c LT	60	if (((flags ^ REISERFS_I(inode)->
	61	i_attrs) & (REISERFS_IMMUTABLE_FL \|
	62	REISERFS_APPEND_FL))
	63	&& !capable(CAP_LINUX_IMMUTABLE))
	64	return -EPERM;
	65
	66	if ((flags & REISERFS_NOTAIL_FL) &&
	67	S_ISREG(inode->i_mode)) {
1da177e4 LT	68	int result;
1da177e4 LT	69
bd4c625c LT	70	result = reiserfs_unpack(inode, filp);
bd4c625c LT	71	if (result)
1da177e4	72	return result;
bd4c625c LT	73	}
	74	sd_attrs_to_i_attrs(flags, inode);
	75	REISERFS_I(inode)->i_attrs = flags;
	76	inode->i_ctime = CURRENT_TIME_SEC;
	77	mark_inode_dirty(inode);
	78	return 0;
1da177e4	79	}
1da177e4	80	case REISERFS_IOC_GETVERSION:
bd4c625c	81	return put_user(inode->i_generation, (int __user *)arg);
1da177e4 LT	82	case REISERFS_IOC_SETVERSION:
	83	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
	84	return -EPERM;
	85	if (IS_RDONLY(inode))
	86	return -EROFS;
bd4c625c LT	87	if (get_user(inode->i_generation, (int __user *)arg))
bd4c625c LT	88	return -EFAULT;
1da177e4 LT	89	inode->i_ctime = CURRENT_TIME_SEC;
	90	mark_inode_dirty(inode);
	91	return 0;
	92	default:
	93	return -ENOTTY;
	94	}
	95	}
	96
	97	/*
	98	** reiserfs_unpack
	99	** Function try to convert tail from direct item into indirect.
	100	** It set up nopack attribute in the REISERFS_I(inode)->nopack
	101	*/
bd4c625c	102	static int reiserfs_unpack(struct inode inode, struct file filp)
1da177e4	103	{
bd4c625c LT	104	int retval = 0;
	105	int index;
	106	struct page *page;
	107	struct address_space *mapping;
	108	unsigned long write_from;
	109	unsigned long blocksize = inode->i_sb->s_blocksize;
	110
	111	if (inode->i_size == 0) {
	112	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
	113	return 0;
	114	}
	115	/* ioctl already done */
	116	if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
	117	return 0;
	118	}
bd4c625c LT	119
	120	/* we need to make sure nobody is changing the file size beneath
	121	** us
	122	*/
1b1dcc1b	123	mutex_lock(&inode->i_mutex);
b5f3953c	124	reiserfs_write_lock(inode->i_sb);
bd4c625c LT	125
	126	write_from = inode->i_size & (blocksize - 1);
	127	/* if we are on a block boundary, we are already unpacked. */
	128	if (write_from == 0) {
	129	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
	130	goto out;
	131	}
	132
	133	/* we unpack by finding the page with the tail, and calling
	134	** reiserfs_prepare_write on that page. This will force a
	135	** reiserfs_get_block to unpack the tail for us.
	136	*/
	137	index = inode->i_size >> PAGE_CACHE_SHIFT;
	138	mapping = inode->i_mapping;
	139	page = grab_cache_page(mapping, index);
	140	retval = -ENOMEM;
	141	if (!page) {
	142	goto out;
	143	}
	144	retval =
	145	mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
	146	if (retval)
	147	goto out_unlock;
	148
	149	/* conversion can change page contents, must flush */
	150	flush_dcache_page(page);
	151	retval =
	152	mapping->a_ops->commit_write(NULL, page, write_from, write_from);
1da177e4	153	REISERFS_I(inode)->i_flags \|= i_nopack_mask;
bd4c625c LT	154
	155	out_unlock:
	156	unlock_page(page);
	157	page_cache_release(page);
	158
	159	out:
1b1dcc1b	160	mutex_unlock(&inode->i_mutex);
bd4c625c LT	161	reiserfs_write_unlock(inode->i_sb);
bd4c625c LT	162	return retval;
1da177e4	163	}