[deliverable/linux.git] / fs / fat / file.c

/*
 *  linux/fs/fat/file.c
 *
 *  Written 1992,1993 by Werner Almesberger
 *
 *  regular file handling primitives for fat-based filesystems
 */

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/time.h>
#include <linux/msdos_fs.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include <linux/blkdev.h>
#include <linux/fsnotify.h>
#include <linux/security.h>

int fat_generic_ioctl(struct inode *inode, struct file *filp,
		      unsigned int cmd, unsigned long arg)
{
	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	u32 __user *user_attr = (u32 __user *)arg;

	switch (cmd) {
	case FAT_IOCTL_GET_ATTRIBUTES:
	{
		u32 attr;

		if (inode->i_ino == MSDOS_ROOT_INO)
			attr = ATTR_DIR;
		else
			attr = fat_attr(inode);

		return put_user(attr, user_attr);
	}
	case FAT_IOCTL_SET_ATTRIBUTES:
	{
		u32 attr, oldattr;
		int err, is_dir = S_ISDIR(inode->i_mode);
		struct iattr ia;

		err = get_user(attr, user_attr);
		if (err)
			return err;

		mutex_lock(&inode->i_mutex);

		err = mnt_want_write(filp->f_path.mnt);
		if (err)
			goto up_no_drop_write;

		/*
		 * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
		 * prevents the user from turning us into a VFAT
		 * longname entry.  Also, we obviously can't set
		 * any of the NTFS attributes in the high 24 bits.
		 */
		attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
		/* Merge in ATTR_VOLUME and ATTR_DIR */
		attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
			(is_dir ? ATTR_DIR : 0);
		oldattr = fat_attr(inode);

		/* Equivalent to a chmod() */
		ia.ia_valid = ATTR_MODE | ATTR_CTIME;
		ia.ia_ctime = current_fs_time(inode->i_sb);
		if (is_dir) {
			ia.ia_mode = MSDOS_MKMODE(attr,
				S_IRWXUGO & ~sbi->options.fs_dmask)
				| S_IFDIR;
		} else {
			ia.ia_mode = MSDOS_MKMODE(attr,
				(S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO))
				& ~sbi->options.fs_fmask)
				| S_IFREG;
		}

		/* The root directory has no attributes */
		if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
			err = -EINVAL;
			goto up;
		}

		if (sbi->options.sys_immutable) {
			if ((attr | oldattr) & ATTR_SYS) {
				if (!capable(CAP_LINUX_IMMUTABLE)) {
					err = -EPERM;
					goto up;
				}
			}
		}

		/*
		 * The security check is questionable...  We single
		 * out the RO attribute for checking by the security
		 * module, just because it maps to a file mode.
		 */
		err = security_inode_setattr(filp->f_path.dentry, &ia);
		if (err)
			goto up;

		/* This MUST be done before doing anything irreversible... */
		err = fat_setattr(filp->f_path.dentry, &ia);
		if (err)
			goto up;

		fsnotify_change(filp->f_path.dentry, ia.ia_valid);
		if (sbi->options.sys_immutable) {
			if (attr & ATTR_SYS)
				inode->i_flags |= S_IMMUTABLE;
			else
				inode->i_flags &= S_IMMUTABLE;
		}

		MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
		mark_inode_dirty(inode);
up:
		mnt_drop_write(filp->f_path.mnt);
up_no_drop_write:
		mutex_unlock(&inode->i_mutex);
		return err;
	}
	default:
		return -ENOTTY;	/* Inappropriate ioctl for device */
	}
}

static int fat_file_release(struct inode *inode, struct file *filp)
{
	if ((filp->f_mode & FMODE_WRITE) &&
	     MSDOS_SB(inode->i_sb)->options.flush) {
		fat_flush_inodes(inode->i_sb, inode, NULL);
		congestion_wait(WRITE, HZ/10);
	}
	return 0;
}

const struct file_operations fat_file_operations = {
	.llseek		= generic_file_llseek,
	.read		= do_sync_read,
	.write		= do_sync_write,
	.aio_read	= generic_file_aio_read,
	.aio_write	= generic_file_aio_write,
	.mmap		= generic_file_mmap,
	.release	= fat_file_release,
	.ioctl		= fat_generic_ioctl,
	.fsync		= file_fsync,
	.splice_read	= generic_file_splice_read,
};

static int fat_cont_expand(struct inode *inode, loff_t size)
{
	struct address_space *mapping = inode->i_mapping;
	loff_t start = inode->i_size, count = size - inode->i_size;
	int err;

	err = generic_cont_expand_simple(inode, size);
	if (err)
		goto out;

	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	mark_inode_dirty(inode);
	if (IS_SYNC(inode))
		err = sync_page_range_nolock(inode, mapping, start, count);
out:
	return err;
}

/* Free all clusters after the skip'th cluster. */
static int fat_free(struct inode *inode, int skip)
{
	struct super_block *sb = inode->i_sb;
	int err, wait, free_start, i_start, i_logstart;

	if (MSDOS_I(inode)->i_start == 0)
		return 0;

	fat_cache_inval_inode(inode);

	wait = IS_DIRSYNC(inode);
	i_start = free_start = MSDOS_I(inode)->i_start;
	i_logstart = MSDOS_I(inode)->i_logstart;

	/* First, we write the new file size. */
	if (!skip) {
		MSDOS_I(inode)->i_start = 0;
		MSDOS_I(inode)->i_logstart = 0;
	}
	MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	if (wait) {
		err = fat_sync_inode(inode);
		if (err) {
			MSDOS_I(inode)->i_start = i_start;
			MSDOS_I(inode)->i_logstart = i_logstart;
			return err;
		}
	} else
		mark_inode_dirty(inode);

	/* Write a new EOF, and get the remaining cluster chain for freeing. */
	if (skip) {
		struct fat_entry fatent;
		int ret, fclus, dclus;

		ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
		if (ret < 0)
			return ret;
		else if (ret == FAT_ENT_EOF)
			return 0;

		fatent_init(&fatent);
		ret = fat_ent_read(inode, &fatent, dclus);
		if (ret == FAT_ENT_EOF) {
			fatent_brelse(&fatent);
			return 0;
		} else if (ret == FAT_ENT_FREE) {
			fat_fs_panic(sb,
				     "%s: invalid cluster chain (i_pos %lld)",
				     __func__, MSDOS_I(inode)->i_pos);
			ret = -EIO;
		} else if (ret > 0) {
			err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
			if (err)
				ret = err;
		}
		fatent_brelse(&fatent);
		if (ret < 0)
			return ret;

		free_start = ret;
	}
	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);

	/* Freeing the remained cluster chain */
	return fat_free_clusters(inode, free_start);
}

void fat_truncate(struct inode *inode)
{
	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	const unsigned int cluster_size = sbi->cluster_size;
	int nr_clusters;

	/*
	 * This protects against truncating a file bigger than it was then
	 * trying to write into the hole.
	 */
	if (MSDOS_I(inode)->mmu_private > inode->i_size)
		MSDOS_I(inode)->mmu_private = inode->i_size;

	nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;

	fat_free(inode, nr_clusters);
	fat_flush_inodes(inode->i_sb, inode, NULL);
}

int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
	struct inode *inode = dentry->d_inode;
	generic_fillattr(inode, stat);
	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
	return 0;
}
EXPORT_SYMBOL_GPL(fat_getattr);

static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
			     struct inode *inode, umode_t *mode_ptr)
{
	mode_t mask, perm;

	/*
	 * Note, the basic check is already done by a caller of
	 * (attr->ia_mode & ~MSDOS_VALID_MODE)
	 */

	if (S_ISREG(inode->i_mode))
		mask = sbi->options.fs_fmask;
	else
		mask = sbi->options.fs_dmask;

	perm = *mode_ptr & ~(S_IFMT | mask);

	/*
	 * Of the r and x bits, all (subject to umask) must be present. Of the
	 * w bits, either all (subject to umask) or none must be present.
	 */
	if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
		return -EPERM;
	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
		return -EPERM;

	*mode_ptr &= S_IFMT | perm;

	return 0;
}

static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
{
	mode_t allow_utime = sbi->options.allow_utime;

	if (current->fsuid != inode->i_uid) {
		if (in_group_p(inode->i_gid))
			allow_utime >>= 3;
		if (allow_utime & MAY_WRITE)
			return 1;
	}

	/* use a default check */
	return 0;
}

int fat_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
	struct inode *inode = dentry->d_inode;
	int error = 0;
	unsigned int ia_valid;

	/*
	 * Expand the file. Since inode_setattr() updates ->i_size
	 * before calling the ->truncate(), but FAT needs to fill the
	 * hole before it.
	 */
	if (attr->ia_valid & ATTR_SIZE) {
		if (attr->ia_size > inode->i_size) {
			error = fat_cont_expand(inode, attr->ia_size);
			if (error || attr->ia_valid == ATTR_SIZE)
				goto out;
			attr->ia_valid &= ~ATTR_SIZE;
		}
	}

	/* Check for setting the inode time. */
	ia_valid = attr->ia_valid;
	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) {
		if (fat_allow_set_time(sbi, inode))
			attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET);
	}

	error = inode_change_ok(inode, attr);
	attr->ia_valid = ia_valid;
	if (error) {
		if (sbi->options.quiet)
			error = 0;
		goto out;
	}

	if (((attr->ia_valid & ATTR_UID) &&
	     (attr->ia_uid != sbi->options.fs_uid)) ||
	    ((attr->ia_valid & ATTR_GID) &&
	     (attr->ia_gid != sbi->options.fs_gid)) ||
	    ((attr->ia_valid & ATTR_MODE) &&
	     (attr->ia_mode & ~MSDOS_VALID_MODE)))
		error = -EPERM;

	if (error) {
		if (sbi->options.quiet)
			error = 0;
		goto out;
	}

	/*
	 * We don't return -EPERM here. Yes, strange, but this is too
	 * old behavior.
	 */
	if (attr->ia_valid & ATTR_MODE) {
		if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
			attr->ia_valid &= ~ATTR_MODE;
	}

	error = inode_setattr(inode, attr);
out:
	return error;
}
EXPORT_SYMBOL_GPL(fat_setattr);

const struct inode_operations fat_file_inode_operations = {
	.truncate	= fat_truncate,
	.setattr	= fat_setattr,
	.getattr	= fat_getattr,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/fat/file.c
	3	*
	4	* Written 1992,1993 by Werner Almesberger
	5	*
	6	* regular file handling primitives for fat-based filesystems
	7	*/
	8
16f7e0fe	9	#include <linux/capability.h>
1da177e4	10	#include <linux/module.h>
42a74f20	11	#include <linux/mount.h>
1da177e4 LT	12	#include <linux/time.h>
1da177e4 LT	13	#include <linux/msdos_fs.h>
1da177e4	14	#include <linux/buffer_head.h>
05eb0b51	15	#include <linux/writeback.h>
3fcfab16	16	#include <linux/backing-dev.h>
ae78bf9c	17	#include <linux/blkdev.h>
b1da47e2 MS	18	#include <linux/fsnotify.h>
b1da47e2 MS	19	#include <linux/security.h>
1da177e4	20
1da177e4 LT	21	int fat_generic_ioctl(struct inode inode, struct file filp,
	22	unsigned int cmd, unsigned long arg)
	23	{
	24	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	25	u32 __user user_attr = (u32 __user )arg;
	26
	27	switch (cmd) {
	28	case FAT_IOCTL_GET_ATTRIBUTES:
	29	{
	30	u32 attr;
	31
	32	if (inode->i_ino == MSDOS_ROOT_INO)
	33	attr = ATTR_DIR;
	34	else
	35	attr = fat_attr(inode);
	36
	37	return put_user(attr, user_attr);
	38	}
	39	case FAT_IOCTL_SET_ATTRIBUTES:
	40	{
	41	u32 attr, oldattr;
	42	int err, is_dir = S_ISDIR(inode->i_mode);
	43	struct iattr ia;
	44
	45	err = get_user(attr, user_attr);
	46	if (err)
	47	return err;
	48
1b1dcc1b	49	mutex_lock(&inode->i_mutex);
1da177e4	50
42a74f20 DH	51	err = mnt_want_write(filp->f_path.mnt);
	52	if (err)
	53	goto up_no_drop_write;
1da177e4 LT	54
	55	/*
	56	* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
	57	* prevents the user from turning us into a VFAT
	58	* longname entry. Also, we obviously can't set
	59	* any of the NTFS attributes in the high 24 bits.
	60	*/
	61	attr &= 0xff & ~(ATTR_VOLUME \| ATTR_DIR);
	62	/* Merge in ATTR_VOLUME and ATTR_DIR */
	63	attr \|= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) \|
	64	(is_dir ? ATTR_DIR : 0);
	65	oldattr = fat_attr(inode);
	66
	67	/* Equivalent to a chmod() */
	68	ia.ia_valid = ATTR_MODE \| ATTR_CTIME;
b1da47e2	69	ia.ia_ctime = current_fs_time(inode->i_sb);
1da177e4 LT	70	if (is_dir) {
	71	ia.ia_mode = MSDOS_MKMODE(attr,
	72	S_IRWXUGO & ~sbi->options.fs_dmask)
	73	\| S_IFDIR;
	74	} else {
	75	ia.ia_mode = MSDOS_MKMODE(attr,
	76	(S_IRUGO \| S_IWUGO \| (inode->i_mode & S_IXUGO))
	77	& ~sbi->options.fs_fmask)
	78	\| S_IFREG;
	79	}
	80
	81	/* The root directory has no attributes */
	82	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
	83	err = -EINVAL;
	84	goto up;
	85	}
	86
	87	if (sbi->options.sys_immutable) {
	88	if ((attr \| oldattr) & ATTR_SYS) {
	89	if (!capable(CAP_LINUX_IMMUTABLE)) {
	90	err = -EPERM;
	91	goto up;
	92	}
	93	}
	94	}
	95
b1da47e2 MS	96	/*
	97	* The security check is questionable... We single
	98	* out the RO attribute for checking by the security
	99	* module, just because it maps to a file mode.
	100	*/
	101	err = security_inode_setattr(filp->f_path.dentry, &ia);
	102	if (err)
	103	goto up;
	104
1da177e4	105	/* This MUST be done before doing anything irreversible... */
b1da47e2	106	err = fat_setattr(filp->f_path.dentry, &ia);
1da177e4 LT	107	if (err)
	108	goto up;
	109
b1da47e2	110	fsnotify_change(filp->f_path.dentry, ia.ia_valid);
1da177e4 LT	111	if (sbi->options.sys_immutable) {
	112	if (attr & ATTR_SYS)
	113	inode->i_flags \|= S_IMMUTABLE;
	114	else
	115	inode->i_flags &= S_IMMUTABLE;
	116	}
	117
	118	MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED;
	119	mark_inode_dirty(inode);
42a74f20 DH	120	up:
	121	mnt_drop_write(filp->f_path.mnt);
	122	up_no_drop_write:
1b1dcc1b	123	mutex_unlock(&inode->i_mutex);
1da177e4 LT	124	return err;
	125	}
	126	default:
	127	return -ENOTTY; /* Inappropriate ioctl for device */
	128	}
	129	}
	130
ae78bf9c CM	131	static int fat_file_release(struct inode inode, struct file filp)
	132	{
	133	if ((filp->f_mode & FMODE_WRITE) &&
	134	MSDOS_SB(inode->i_sb)->options.flush) {
	135	fat_flush_inodes(inode->i_sb, inode, NULL);
3fcfab16	136	congestion_wait(WRITE, HZ/10);
ae78bf9c CM	137	}
	138	return 0;
	139	}
	140
4b6f5d20	141	const struct file_operations fat_file_operations = {
1da177e4 LT	142	.llseek = generic_file_llseek,
	143	.read = do_sync_read,
	144	.write = do_sync_write,
1da177e4	145	.aio_read = generic_file_aio_read,
ef402268	146	.aio_write = generic_file_aio_write,
1da177e4	147	.mmap = generic_file_mmap,
ae78bf9c	148	.release = fat_file_release,
1da177e4 LT	149	.ioctl = fat_generic_ioctl,
1da177e4 LT	150	.fsync = file_fsync,
5ffc4ef4	151	.splice_read = generic_file_splice_read,
1da177e4 LT	152	};
1da177e4 LT	153
05eb0b51 OH	154	static int fat_cont_expand(struct inode *inode, loff_t size)
	155	{
	156	struct address_space *mapping = inode->i_mapping;
	157	loff_t start = inode->i_size, count = size - inode->i_size;
	158	int err;
	159
	160	err = generic_cont_expand_simple(inode, size);
	161	if (err)
	162	goto out;
	163
	164	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	165	mark_inode_dirty(inode);
	166	if (IS_SYNC(inode))
	167	err = sync_page_range_nolock(inode, mapping, start, count);
	168	out:
	169	return err;
	170	}
	171
1da177e4 LT	172	/* Free all clusters after the skip'th cluster. */
	173	static int fat_free(struct inode *inode, int skip)
	174	{
	175	struct super_block *sb = inode->i_sb;
	176	int err, wait, free_start, i_start, i_logstart;
	177
	178	if (MSDOS_I(inode)->i_start == 0)
	179	return 0;
	180
3b641407 OH	181	fat_cache_inval_inode(inode);
3b641407 OH	182
1da177e4	183	wait = IS_DIRSYNC(inode);
3b641407 OH	184	i_start = free_start = MSDOS_I(inode)->i_start;
	185	i_logstart = MSDOS_I(inode)->i_logstart;
	186
	187	/* First, we write the new file size. */
	188	if (!skip) {
	189	MSDOS_I(inode)->i_start = 0;
	190	MSDOS_I(inode)->i_logstart = 0;
	191	}
	192	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
	193	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	194	if (wait) {
	195	err = fat_sync_inode(inode);
	196	if (err) {
	197	MSDOS_I(inode)->i_start = i_start;
	198	MSDOS_I(inode)->i_logstart = i_logstart;
	199	return err;
	200	}
	201	} else
	202	mark_inode_dirty(inode);
	203
	204	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	205	if (skip) {
	206	struct fat_entry fatent;
	207	int ret, fclus, dclus;
	208
	209	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	210	if (ret < 0)
	211	return ret;
	212	else if (ret == FAT_ENT_EOF)
	213	return 0;
	214
	215	fatent_init(&fatent);
	216	ret = fat_ent_read(inode, &fatent, dclus);
	217	if (ret == FAT_ENT_EOF) {
	218	fatent_brelse(&fatent);
	219	return 0;
	220	} else if (ret == FAT_ENT_FREE) {
	221	fat_fs_panic(sb,
	222	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	223	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	224	ret = -EIO;
	225	} else if (ret > 0) {
	226	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	227	if (err)
	228	ret = err;
	229	}
	230	fatent_brelse(&fatent);
	231	if (ret < 0)
	232	return ret;
	233
	234	free_start = ret;
1da177e4	235	}
1da177e4 LT	236	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	237
	238	/* Freeing the remained cluster chain */
	239	return fat_free_clusters(inode, free_start);
1da177e4 LT	240	}
	241
	242	void fat_truncate(struct inode *inode)
	243	{
9c20616c	244	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	245	const unsigned int cluster_size = sbi->cluster_size;
	246	int nr_clusters;
	247
	248	/*
	249	* This protects against truncating a file bigger than it was then
	250	* trying to write into the hole.
	251	*/
	252	if (MSDOS_I(inode)->mmu_private > inode->i_size)
	253	MSDOS_I(inode)->mmu_private = inode->i_size;
	254
	255	nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
	256
1da177e4	257	fat_free(inode, nr_clusters);
ae78bf9c	258	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	259	}
1da177e4 LT	260
da63fc7c OH	261	int fat_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat)
	262	{
	263	struct inode *inode = dentry->d_inode;
	264	generic_fillattr(inode, stat);
	265	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
	266	return 0;
	267	}
	268	EXPORT_SYMBOL_GPL(fat_getattr);
	269
2d518f84 OH	270	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	271	struct inode inode, umode_t mode_ptr)
1278fdd3	272	{
2d518f84	273	mode_t mask, perm;
1278fdd3	274
2d518f84 OH	275	/*
	276	* Note, the basic check is already done by a caller of
	277	* (attr->ia_mode & ~MSDOS_VALID_MODE)
	278	*/
	279
	280	if (S_ISREG(inode->i_mode))
1278fdd3 OH	281	mask = sbi->options.fs_fmask;
	282	else
	283	mask = sbi->options.fs_dmask;
	284
2d518f84 OH	285	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	286
1278fdd3 OH	287	/*
	288	* Of the r and x bits, all (subject to umask) must be present. Of the
	289	* w bits, either all (subject to umask) or none must be present.
	290	*/
2d518f84	291	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	292	return -EPERM;
2d518f84	293	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
1278fdd3 OH	294	return -EPERM;
1278fdd3 OH	295
2d518f84 OH	296	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	297
1278fdd3 OH	298	return 0;
	299	}
	300
1ae43f82 OH	301	static int fat_allow_set_time(struct msdos_sb_info sbi, struct inode inode)
	302	{
	303	mode_t allow_utime = sbi->options.allow_utime;
	304
	305	if (current->fsuid != inode->i_uid) {
	306	if (in_group_p(inode->i_gid))
	307	allow_utime >>= 3;
	308	if (allow_utime & MAY_WRITE)
	309	return 1;
	310	}
	311
	312	/* use a default check */
	313	return 0;
	314	}
	315
1278fdd3 OH	316	int fat_setattr(struct dentry dentry, struct iattr attr)
	317	{
	318	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
	319	struct inode *inode = dentry->d_inode;
2d518f84	320	int error = 0;
1ae43f82	321	unsigned int ia_valid;
1278fdd3	322
1278fdd3 OH	323	/*
	324	* Expand the file. Since inode_setattr() updates ->i_size
	325	* before calling the ->truncate(), but FAT needs to fill the
	326	* hole before it.
	327	*/
	328	if (attr->ia_valid & ATTR_SIZE) {
	329	if (attr->ia_size > inode->i_size) {
	330	error = fat_cont_expand(inode, attr->ia_size);
	331	if (error \|\| attr->ia_valid == ATTR_SIZE)
	332	goto out;
	333	attr->ia_valid &= ~ATTR_SIZE;
	334	}
	335	}
	336
1ae43f82 OH	337	/* Check for setting the inode time. */
	338	ia_valid = attr->ia_valid;
	339	if (ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET)) {
	340	if (fat_allow_set_time(sbi, inode))
	341	attr->ia_valid &= ~(ATTR_MTIME_SET \| ATTR_ATIME_SET);
	342	}
	343
1278fdd3	344	error = inode_change_ok(inode, attr);
1ae43f82	345	attr->ia_valid = ia_valid;
1278fdd3 OH	346	if (error) {
	347	if (sbi->options.quiet)
	348	error = 0;
	349	goto out;
	350	}
2d518f84	351
1278fdd3 OH	352	if (((attr->ia_valid & ATTR_UID) &&
	353	(attr->ia_uid != sbi->options.fs_uid)) \|\|
	354	((attr->ia_valid & ATTR_GID) &&
e97e8de3 OH	355	(attr->ia_gid != sbi->options.fs_gid)) \|\|
e97e8de3 OH	356	((attr->ia_valid & ATTR_MODE) &&
2d518f84	357	(attr->ia_mode & ~MSDOS_VALID_MODE)))
1278fdd3 OH	358	error = -EPERM;
	359
	360	if (error) {
	361	if (sbi->options.quiet)
	362	error = 0;
	363	goto out;
	364	}
	365
2d518f84 OH	366	/*
	367	* We don't return -EPERM here. Yes, strange, but this is too
	368	* old behavior.
	369	*/
	370	if (attr->ia_valid & ATTR_MODE) {
	371	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	372	attr->ia_valid &= ~ATTR_MODE;
	373	}
1278fdd3	374
2d518f84	375	error = inode_setattr(inode, attr);
1278fdd3	376	out:
1278fdd3 OH	377	return error;
	378	}
	379	EXPORT_SYMBOL_GPL(fat_setattr);
	380
754661f1	381	const struct inode_operations fat_file_inode_operations = {
1da177e4	382	.truncate = fat_truncate,
1278fdd3	383	.setattr = fat_setattr,
da63fc7c	384	.getattr = fat_getattr,
1da177e4	385	};