[linux.git] / fs / attr.c

/*
 *  linux/fs/attr.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  changes by Thomas Schoebel-Theuer
 */

#include <linux/module.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/capability.h>
#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/quotaops.h>
#include <linux/security.h>

/* Taken over from the old code... */

/* POSIX UID/GID verification for setting inode attributes. */
int inode_change_ok(struct inode *inode, struct iattr *attr)
{
	int retval = -EPERM;
	unsigned int ia_valid = attr->ia_valid;

	/* If force is set do it anyway. */
	if (ia_valid & ATTR_FORCE)
		goto fine;

	/* Make sure a caller can chown. */
	if ((ia_valid & ATTR_UID) &&
	    (current->fsuid != inode->i_uid ||
	     attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
		goto error;

	/* Make sure caller can chgrp. */
	if ((ia_valid & ATTR_GID) &&
	    (current->fsuid != inode->i_uid ||
	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
	    !capable(CAP_CHOWN))
		goto error;

	/* Make sure a caller can chmod. */
	if (ia_valid & ATTR_MODE) {
		if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
			goto error;
		/* Also check the setgid bit! */
		if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
				inode->i_gid) && !capable(CAP_FSETID))
			attr->ia_mode &= ~S_ISGID;
	}

	/* Check for setting the inode time. */
	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) {
		if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
			goto error;
	}
fine:
	retval = 0;
error:
	return retval;
}

EXPORT_SYMBOL(inode_change_ok);

int inode_setattr(struct inode * inode, struct iattr * attr)
{
	unsigned int ia_valid = attr->ia_valid;

	if (ia_valid & ATTR_SIZE &&
	    attr->ia_size != i_size_read(inode)) {
		int error = vmtruncate(inode, attr->ia_size);
		if (error)
			return error;
	}

	if (ia_valid & ATTR_UID)
		inode->i_uid = attr->ia_uid;
	if (ia_valid & ATTR_GID)
		inode->i_gid = attr->ia_gid;
	if (ia_valid & ATTR_ATIME)
		inode->i_atime = timespec_trunc(attr->ia_atime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MTIME)
		inode->i_mtime = timespec_trunc(attr->ia_mtime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_CTIME)
		inode->i_ctime = timespec_trunc(attr->ia_ctime,
						inode->i_sb->s_time_gran);
	if (ia_valid & ATTR_MODE) {
		umode_t mode = attr->ia_mode;

		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
			mode &= ~S_ISGID;
		inode->i_mode = mode;
	}
	mark_inode_dirty(inode);

	return 0;
}
EXPORT_SYMBOL(inode_setattr);

int notify_change(struct dentry * dentry, struct iattr * attr)
{
	struct inode *inode = dentry->d_inode;
	mode_t mode;
	int error;
	struct timespec now;
	unsigned int ia_valid = attr->ia_valid;

	mode = inode->i_mode;
	now = current_fs_time(inode->i_sb);

	attr->ia_ctime = now;
	if (!(ia_valid & ATTR_ATIME_SET))
		attr->ia_atime = now;
	if (!(ia_valid & ATTR_MTIME_SET))
		attr->ia_mtime = now;
	if (ia_valid & ATTR_KILL_SUID) {
		attr->ia_valid &= ~ATTR_KILL_SUID;
		if (mode & S_ISUID) {
			if (!(ia_valid & ATTR_MODE)) {
				ia_valid = attr->ia_valid |= ATTR_MODE;
				attr->ia_mode = inode->i_mode;
			}
			attr->ia_mode &= ~S_ISUID;
		}
	}
	if (ia_valid & ATTR_KILL_SGID) {
		attr->ia_valid &= ~ ATTR_KILL_SGID;
		if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
			if (!(ia_valid & ATTR_MODE)) {
				ia_valid = attr->ia_valid |= ATTR_MODE;
				attr->ia_mode = inode->i_mode;
			}
			attr->ia_mode &= ~S_ISGID;
		}
	}
	if (!attr->ia_valid)
		return 0;

	if (ia_valid & ATTR_SIZE)
		down_write(&dentry->d_inode->i_alloc_sem);

	if (inode->i_op && inode->i_op->setattr) {
		error = security_inode_setattr(dentry, attr);
		if (!error)
			error = inode->i_op->setattr(dentry, attr);
	} else {
		error = inode_change_ok(inode, attr);
		if (!error)
			error = security_inode_setattr(dentry, attr);
		if (!error) {
			if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
			    (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid))
				error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
			if (!error)
				error = inode_setattr(inode, attr);
		}
	}

	if (ia_valid & ATTR_SIZE)
		up_write(&dentry->d_inode->i_alloc_sem);

	if (!error)
		fsnotify_change(dentry, ia_valid);

	return error;
}

EXPORT_SYMBOL(notify_change);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/attr.c
	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	* changes by Thomas Schoebel-Theuer
	6	*/
	7
	8	#include <linux/module.h>
	9	#include <linux/time.h>
	10	#include <linux/mm.h>
	11	#include <linux/string.h>
	12	#include <linux/smp_lock.h>
16f7e0fe	13	#include <linux/capability.h>
0eeca283	14	#include <linux/fsnotify.h>
1da177e4 LT	15	#include <linux/fcntl.h>
	16	#include <linux/quotaops.h>
	17	#include <linux/security.h>
1da177e4 LT	18
	19	/* Taken over from the old code... */
	20
	21	/* POSIX UID/GID verification for setting inode attributes. */
	22	int inode_change_ok(struct inode inode, struct iattr attr)
	23	{
	24	int retval = -EPERM;
	25	unsigned int ia_valid = attr->ia_valid;
	26
	27	/* If force is set do it anyway. */
	28	if (ia_valid & ATTR_FORCE)
	29	goto fine;
	30
	31	/* Make sure a caller can chown. */
	32	if ((ia_valid & ATTR_UID) &&
	33	(current->fsuid != inode->i_uid \|\|
	34	attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
	35	goto error;
	36
	37	/* Make sure caller can chgrp. */
	38	if ((ia_valid & ATTR_GID) &&
	39	(current->fsuid != inode->i_uid \|\|
	40	(!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
	41	!capable(CAP_CHOWN))
	42	goto error;
	43
	44	/* Make sure a caller can chmod. */
	45	if (ia_valid & ATTR_MODE) {
	46	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
	47	goto error;
	48	/* Also check the setgid bit! */
	49	if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
	50	inode->i_gid) && !capable(CAP_FSETID))
	51	attr->ia_mode &= ~S_ISGID;
	52	}
	53
	54	/* Check for setting the inode time. */
	55	if (ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET)) {
	56	if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
	57	goto error;
	58	}
	59	fine:
	60	retval = 0;
	61	error:
	62	return retval;
	63	}
	64
	65	EXPORT_SYMBOL(inode_change_ok);
	66
	67	int inode_setattr(struct inode * inode, struct iattr * attr)
	68	{
	69	unsigned int ia_valid = attr->ia_valid;
4a30131e N	70
	71	if (ia_valid & ATTR_SIZE &&
	72	attr->ia_size != i_size_read(inode)) {
	73	int error = vmtruncate(inode, attr->ia_size);
	74	if (error)
	75	return error;
1da177e4 LT	76	}
	77
	78	if (ia_valid & ATTR_UID)
	79	inode->i_uid = attr->ia_uid;
	80	if (ia_valid & ATTR_GID)
	81	inode->i_gid = attr->ia_gid;
	82	if (ia_valid & ATTR_ATIME)
	83	inode->i_atime = timespec_trunc(attr->ia_atime,
	84	inode->i_sb->s_time_gran);
	85	if (ia_valid & ATTR_MTIME)
	86	inode->i_mtime = timespec_trunc(attr->ia_mtime,
	87	inode->i_sb->s_time_gran);
	88	if (ia_valid & ATTR_CTIME)
	89	inode->i_ctime = timespec_trunc(attr->ia_ctime,
	90	inode->i_sb->s_time_gran);
	91	if (ia_valid & ATTR_MODE) {
	92	umode_t mode = attr->ia_mode;
	93
	94	if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
	95	mode &= ~S_ISGID;
	96	inode->i_mode = mode;
	97	}
	98	mark_inode_dirty(inode);
4a30131e N	99
4a30131e N	100	return 0;
1da177e4	101	}
1da177e4 LT	102	EXPORT_SYMBOL(inode_setattr);
1da177e4 LT	103
1da177e4 LT	104	int notify_change(struct dentry * dentry, struct iattr * attr)
	105	{
	106	struct inode *inode = dentry->d_inode;
	107	mode_t mode;
	108	int error;
	109	struct timespec now;
	110	unsigned int ia_valid = attr->ia_valid;
	111
1da177e4 LT	112	mode = inode->i_mode;
	113	now = current_fs_time(inode->i_sb);
	114
	115	attr->ia_ctime = now;
	116	if (!(ia_valid & ATTR_ATIME_SET))
	117	attr->ia_atime = now;
	118	if (!(ia_valid & ATTR_MTIME_SET))
	119	attr->ia_mtime = now;
	120	if (ia_valid & ATTR_KILL_SUID) {
	121	attr->ia_valid &= ~ATTR_KILL_SUID;
	122	if (mode & S_ISUID) {
	123	if (!(ia_valid & ATTR_MODE)) {
	124	ia_valid = attr->ia_valid \|= ATTR_MODE;
	125	attr->ia_mode = inode->i_mode;
	126	}
	127	attr->ia_mode &= ~S_ISUID;
	128	}
	129	}
	130	if (ia_valid & ATTR_KILL_SGID) {
	131	attr->ia_valid &= ~ ATTR_KILL_SGID;
	132	if ((mode & (S_ISGID \| S_IXGRP)) == (S_ISGID \| S_IXGRP)) {
	133	if (!(ia_valid & ATTR_MODE)) {
	134	ia_valid = attr->ia_valid \|= ATTR_MODE;
	135	attr->ia_mode = inode->i_mode;
	136	}
	137	attr->ia_mode &= ~S_ISGID;
	138	}
	139	}
	140	if (!attr->ia_valid)
	141	return 0;
	142
	143	if (ia_valid & ATTR_SIZE)
	144	down_write(&dentry->d_inode->i_alloc_sem);
	145
	146	if (inode->i_op && inode->i_op->setattr) {
	147	error = security_inode_setattr(dentry, attr);
	148	if (!error)
	149	error = inode->i_op->setattr(dentry, attr);
	150	} else {
	151	error = inode_change_ok(inode, attr);
	152	if (!error)
	153	error = security_inode_setattr(dentry, attr);
	154	if (!error) {
	155	if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) \|\|
	156	(ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid))
	157	error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
	158	if (!error)
	159	error = inode_setattr(inode, attr);
	160	}
	161	}
	162
	163	if (ia_valid & ATTR_SIZE)
	164	up_write(&dentry->d_inode->i_alloc_sem);
	165
0eeca283 RL	166	if (!error)
	167	fsnotify_change(dentry, ia_valid);
	168
1da177e4 LT	169	return error;
	170	}
	171
	172	EXPORT_SYMBOL(notify_change);