[mirror_ubuntu-bionic-kernel.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/buffer_head.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include <linux/blkdev.h>
#include <linux/fsnotify.h>
#include <linux/security.h>
#include "fat.h"

static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
{
	u32 attr;

	mutex_lock(&inode->i_mutex);
	attr = fat_make_attrs(inode);
	mutex_unlock(&inode->i_mutex);

	return put_user(attr, user_attr);
}

static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	int is_dir = S_ISDIR(inode->i_mode);
	u32 attr, oldattr;
	struct iattr ia;
	int err;

	err = get_user(attr, user_attr);
	if (err)
		goto out;

	mutex_lock(&inode->i_mutex);
	err = mnt_want_write(file->f_path.mnt);
	if (err)
		goto out_unlock_inode;

	/*
	 * 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_make_attrs(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 = fat_make_mode(sbi, attr, S_IRWXUGO);
	else {
		ia.ia_mode = fat_make_mode(sbi, attr,
			S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
	}

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

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

	/*
	 * 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(file->f_path.dentry, &ia);
	if (err)
		goto out_drop_write;

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

	fsnotify_change(file->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;
	}

	fat_save_attrs(inode, attr);
	mark_inode_dirty(inode);
out_drop_write:
	mnt_drop_write(file->f_path.mnt);
out_unlock_inode:
	mutex_unlock(&inode->i_mutex);
out:
	return err;
}

int fat_generic_ioctl(struct inode *inode, struct file *filp,
		      unsigned int cmd, unsigned long arg)
{
	u32 __user *user_attr = (u32 __user *)arg;

	switch (cmd) {
	case FAT_IOCTL_GET_ATTRIBUTES:
		return fat_ioctl_get_attributes(inode, user_attr);
	case FAT_IOCTL_SET_ATTRIBUTES:
		return fat_ioctl_set_attributes(filp, user_attr);
	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(BLK_RW_ASYNC, HZ/10);
	}
	return 0;
}

int fat_file_fsync(struct file *filp, struct dentry *dentry, int datasync)
{
	struct inode *inode = dentry->d_inode;
	int res, err;

	res = simple_fsync(filp, dentry, datasync);
	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);

	return res ? res : err;
}


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		= fat_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_error(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 & ~FAT_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 fat_mode_can_hold_ro(inode) is false, can't change w bits.
	 */
	if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
		return -EPERM;
	if (fat_mode_can_hold_ro(inode)) {
		if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
			return -EPERM;
	} else {
		if ((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;
}

#define TIMES_SET_FLAGS	(ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
/* valid file mode bits */
#define FAT_VALID_MODE	(S_IFREG | S_IFDIR | S_IRWXUGO)

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;
	unsigned int ia_valid;
	int error;

	/*
	 * 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 & TIMES_SET_FLAGS) {
		if (fat_allow_set_time(sbi, inode))
			attr->ia_valid &= ~TIMES_SET_FLAGS;
	}

	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 & ~FAT_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;
	}

	if (attr->ia_valid)
		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	12	#include <linux/time.h>
1da177e4	13	#include <linux/buffer_head.h>
05eb0b51	14	#include <linux/writeback.h>
3fcfab16	15	#include <linux/backing-dev.h>
ae78bf9c	16	#include <linux/blkdev.h>
b1da47e2 MS	17	#include <linux/fsnotify.h>
b1da47e2 MS	18	#include <linux/security.h>
9e975dae	19	#include "fat.h"
1da177e4	20
21bea495 CH	21	static int fat_ioctl_get_attributes(struct inode inode, u32 __user user_attr)
	22	{
	23	u32 attr;
	24
	25	mutex_lock(&inode->i_mutex);
	26	attr = fat_make_attrs(inode);
	27	mutex_unlock(&inode->i_mutex);
	28
	29	return put_user(attr, user_attr);
	30	}
	31
	32	static int fat_ioctl_set_attributes(struct file file, u32 __user user_attr)
1da177e4	33	{
21bea495	34	struct inode *inode = file->f_path.dentry->d_inode;
1da177e4	35	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
21bea495 CH	36	int is_dir = S_ISDIR(inode->i_mode);
	37	u32 attr, oldattr;
	38	struct iattr ia;
	39	int err;
1da177e4	40
21bea495 CH	41	err = get_user(attr, user_attr);
	42	if (err)
	43	goto out;
1da177e4	44
21bea495 CH	45	mutex_lock(&inode->i_mutex);
	46	err = mnt_want_write(file->f_path.mnt);
	47	if (err)
	48	goto out_unlock_inode;
	49
	50	/*
	51	* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
	52	* prevents the user from turning us into a VFAT
	53	* longname entry. Also, we obviously can't set
	54	* any of the NTFS attributes in the high 24 bits.
	55	*/
	56	attr &= 0xff & ~(ATTR_VOLUME \| ATTR_DIR);
	57	/* Merge in ATTR_VOLUME and ATTR_DIR */
	58	attr \|= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) \|
	59	(is_dir ? ATTR_DIR : 0);
	60	oldattr = fat_make_attrs(inode);
	61
	62	/* Equivalent to a chmod() */
	63	ia.ia_valid = ATTR_MODE \| ATTR_CTIME;
	64	ia.ia_ctime = current_fs_time(inode->i_sb);
	65	if (is_dir)
	66	ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
	67	else {
	68	ia.ia_mode = fat_make_mode(sbi, attr,
	69	S_IRUGO \| S_IWUGO \| (inode->i_mode & S_IXUGO));
	70	}
1da177e4	71
21bea495 CH	72	/* The root directory has no attributes */
	73	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
	74	err = -EINVAL;
	75	goto out_drop_write;
1da177e4	76	}
1da177e4	77
21bea495 CH	78	if (sbi->options.sys_immutable &&
	79	((attr \| oldattr) & ATTR_SYS) &&
	80	!capable(CAP_LINUX_IMMUTABLE)) {
	81	err = -EPERM;
	82	goto out_drop_write;
	83	}
1da177e4	84
21bea495 CH	85	/*
	86	* The security check is questionable... We single
	87	* out the RO attribute for checking by the security
	88	* module, just because it maps to a file mode.
	89	*/
	90	err = security_inode_setattr(file->f_path.dentry, &ia);
	91	if (err)
	92	goto out_drop_write;
1da177e4	93
21bea495 CH	94	/* This MUST be done before doing anything irreversible... */
	95	err = fat_setattr(file->f_path.dentry, &ia);
	96	if (err)
	97	goto out_drop_write;
	98
	99	fsnotify_change(file->f_path.dentry, ia.ia_valid);
	100	if (sbi->options.sys_immutable) {
	101	if (attr & ATTR_SYS)
	102	inode->i_flags \|= S_IMMUTABLE;
	103	else
	104	inode->i_flags &= S_IMMUTABLE;
	105	}
1da177e4	106
21bea495 CH	107	fat_save_attrs(inode, attr);
	108	mark_inode_dirty(inode);
	109	out_drop_write:
	110	mnt_drop_write(file->f_path.mnt);
	111	out_unlock_inode:
	112	mutex_unlock(&inode->i_mutex);
	113	out:
	114	return err;
	115	}
1da177e4	116
1da177e4 LT	117	int fat_generic_ioctl(struct inode inode, struct file filp,
	118	unsigned int cmd, unsigned long arg)
	119	{
1da177e4	120	u32 __user user_attr = (u32 __user )arg;
1da177e4	121
1da177e4 LT	122	switch (cmd) {
1da177e4 LT	123	case FAT_IOCTL_GET_ATTRIBUTES:
21bea495	124	return fat_ioctl_get_attributes(inode, user_attr);
1da177e4	125	case FAT_IOCTL_SET_ATTRIBUTES:
21bea495	126	return fat_ioctl_set_attributes(filp, user_attr);
1da177e4 LT	127	default:
	128	return -ENOTTY; /* Inappropriate ioctl for device */
	129	}
	130	}
	131
ae78bf9c CM	132	static int fat_file_release(struct inode inode, struct file filp)
	133	{
	134	if ((filp->f_mode & FMODE_WRITE) &&
	135	MSDOS_SB(inode->i_sb)->options.flush) {
	136	fat_flush_inodes(inode->i_sb, inode, NULL);
8aa7e847	137	congestion_wait(BLK_RW_ASYNC, HZ/10);
ae78bf9c CM	138	}
	139	return 0;
	140	}
	141
b522412a AV	142	int fat_file_fsync(struct file filp, struct dentry dentry, int datasync)
	143	{
	144	struct inode *inode = dentry->d_inode;
	145	int res, err;
	146
	147	res = simple_fsync(filp, dentry, datasync);
	148	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
	149
	150	return res ? res : err;
	151	}
	152
	153
4b6f5d20	154	const struct file_operations fat_file_operations = {
1da177e4 LT	155	.llseek = generic_file_llseek,
	156	.read = do_sync_read,
	157	.write = do_sync_write,
1da177e4	158	.aio_read = generic_file_aio_read,
ef402268	159	.aio_write = generic_file_aio_write,
1da177e4	160	.mmap = generic_file_mmap,
ae78bf9c	161	.release = fat_file_release,
1da177e4	162	.ioctl = fat_generic_ioctl,
b522412a	163	.fsync = fat_file_fsync,
5ffc4ef4	164	.splice_read = generic_file_splice_read,
1da177e4 LT	165	};
1da177e4 LT	166
05eb0b51 OH	167	static int fat_cont_expand(struct inode *inode, loff_t size)
	168	{
	169	struct address_space *mapping = inode->i_mapping;
	170	loff_t start = inode->i_size, count = size - inode->i_size;
	171	int err;
	172
	173	err = generic_cont_expand_simple(inode, size);
	174	if (err)
	175	goto out;
	176
	177	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	178	mark_inode_dirty(inode);
	179	if (IS_SYNC(inode))
	180	err = sync_page_range_nolock(inode, mapping, start, count);
	181	out:
	182	return err;
	183	}
	184
1da177e4 LT	185	/* Free all clusters after the skip'th cluster. */
	186	static int fat_free(struct inode *inode, int skip)
	187	{
	188	struct super_block *sb = inode->i_sb;
	189	int err, wait, free_start, i_start, i_logstart;
	190
	191	if (MSDOS_I(inode)->i_start == 0)
	192	return 0;
	193
3b641407 OH	194	fat_cache_inval_inode(inode);
3b641407 OH	195
1da177e4	196	wait = IS_DIRSYNC(inode);
3b641407 OH	197	i_start = free_start = MSDOS_I(inode)->i_start;
	198	i_logstart = MSDOS_I(inode)->i_logstart;
	199
	200	/* First, we write the new file size. */
	201	if (!skip) {
	202	MSDOS_I(inode)->i_start = 0;
	203	MSDOS_I(inode)->i_logstart = 0;
	204	}
	205	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
	206	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	207	if (wait) {
	208	err = fat_sync_inode(inode);
	209	if (err) {
	210	MSDOS_I(inode)->i_start = i_start;
	211	MSDOS_I(inode)->i_logstart = i_logstart;
	212	return err;
	213	}
	214	} else
	215	mark_inode_dirty(inode);
	216
	217	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	218	if (skip) {
	219	struct fat_entry fatent;
	220	int ret, fclus, dclus;
	221
	222	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	223	if (ret < 0)
	224	return ret;
	225	else if (ret == FAT_ENT_EOF)
	226	return 0;
	227
	228	fatent_init(&fatent);
	229	ret = fat_ent_read(inode, &fatent, dclus);
	230	if (ret == FAT_ENT_EOF) {
	231	fatent_brelse(&fatent);
	232	return 0;
	233	} else if (ret == FAT_ENT_FREE) {
85c78591	234	fat_fs_error(sb,
1da177e4	235	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	236	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	237	ret = -EIO;
	238	} else if (ret > 0) {
	239	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	240	if (err)
	241	ret = err;
	242	}
	243	fatent_brelse(&fatent);
	244	if (ret < 0)
	245	return ret;
	246
	247	free_start = ret;
1da177e4	248	}
1da177e4 LT	249	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	250
	251	/* Freeing the remained cluster chain */
	252	return fat_free_clusters(inode, free_start);
1da177e4 LT	253	}
	254
	255	void fat_truncate(struct inode *inode)
	256	{
9c20616c	257	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	258	const unsigned int cluster_size = sbi->cluster_size;
	259	int nr_clusters;
	260
	261	/*
	262	* This protects against truncating a file bigger than it was then
	263	* trying to write into the hole.
	264	*/
	265	if (MSDOS_I(inode)->mmu_private > inode->i_size)
	266	MSDOS_I(inode)->mmu_private = inode->i_size;
	267
	268	nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
	269
1da177e4	270	fat_free(inode, nr_clusters);
ae78bf9c	271	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	272	}
1da177e4 LT	273
da63fc7c OH	274	int fat_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat)
	275	{
	276	struct inode *inode = dentry->d_inode;
	277	generic_fillattr(inode, stat);
	278	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
	279	return 0;
	280	}
	281	EXPORT_SYMBOL_GPL(fat_getattr);
	282
2d518f84 OH	283	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	284	struct inode inode, umode_t mode_ptr)
1278fdd3	285	{
2d518f84	286	mode_t mask, perm;
1278fdd3	287
2d518f84 OH	288	/*
2d518f84 OH	289	* Note, the basic check is already done by a caller of
9c0aa1b8	290	* (attr->ia_mode & ~FAT_VALID_MODE)
2d518f84 OH	291	*/
	292
	293	if (S_ISREG(inode->i_mode))
1278fdd3 OH	294	mask = sbi->options.fs_fmask;
	295	else
	296	mask = sbi->options.fs_dmask;
	297
2d518f84 OH	298	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	299
1278fdd3 OH	300	/*
	301	* Of the r and x bits, all (subject to umask) must be present. Of the
	302	* w bits, either all (subject to umask) or none must be present.
dfc209c0 OH	303	*
dfc209c0 OH	304	* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
1278fdd3	305	*/
2d518f84	306	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	307	return -EPERM;
dfc209c0 OH	308	if (fat_mode_can_hold_ro(inode)) {
	309	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
	310	return -EPERM;
	311	} else {
	312	if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
	313	return -EPERM;
	314	}
1278fdd3	315
2d518f84 OH	316	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	317
1278fdd3 OH	318	return 0;
	319	}
	320
1ae43f82 OH	321	static int fat_allow_set_time(struct msdos_sb_info sbi, struct inode inode)
	322	{
	323	mode_t allow_utime = sbi->options.allow_utime;
	324
f0ce7ee3	325	if (current_fsuid() != inode->i_uid) {
1ae43f82 OH	326	if (in_group_p(inode->i_gid))
	327	allow_utime >>= 3;
	328	if (allow_utime & MAY_WRITE)
	329	return 1;
	330	}
	331
	332	/* use a default check */
	333	return 0;
	334	}
	335
17263849	336	#define TIMES_SET_FLAGS (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)
9c0aa1b8 OH	337	/* valid file mode bits */
9c0aa1b8 OH	338	#define FAT_VALID_MODE (S_IFREG \| S_IFDIR \| S_IRWXUGO)
17263849	339
1278fdd3 OH	340	int fat_setattr(struct dentry dentry, struct iattr attr)
	341	{
	342	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
	343	struct inode *inode = dentry->d_inode;
1ae43f82	344	unsigned int ia_valid;
dfc209c0	345	int error;
1278fdd3	346
1278fdd3 OH	347	/*
	348	* Expand the file. Since inode_setattr() updates ->i_size
	349	* before calling the ->truncate(), but FAT needs to fill the
	350	* hole before it.
	351	*/
	352	if (attr->ia_valid & ATTR_SIZE) {
	353	if (attr->ia_size > inode->i_size) {
	354	error = fat_cont_expand(inode, attr->ia_size);
	355	if (error \|\| attr->ia_valid == ATTR_SIZE)
	356	goto out;
	357	attr->ia_valid &= ~ATTR_SIZE;
	358	}
	359	}
	360
1ae43f82 OH	361	/* Check for setting the inode time. */
1ae43f82 OH	362	ia_valid = attr->ia_valid;
17263849	363	if (ia_valid & TIMES_SET_FLAGS) {
1ae43f82	364	if (fat_allow_set_time(sbi, inode))
17263849	365	attr->ia_valid &= ~TIMES_SET_FLAGS;
1ae43f82 OH	366	}
1ae43f82 OH	367
1278fdd3	368	error = inode_change_ok(inode, attr);
1ae43f82	369	attr->ia_valid = ia_valid;
1278fdd3 OH	370	if (error) {
	371	if (sbi->options.quiet)
	372	error = 0;
	373	goto out;
	374	}
2d518f84	375
1278fdd3 OH	376	if (((attr->ia_valid & ATTR_UID) &&
	377	(attr->ia_uid != sbi->options.fs_uid)) \|\|
	378	((attr->ia_valid & ATTR_GID) &&
e97e8de3 OH	379	(attr->ia_gid != sbi->options.fs_gid)) \|\|
e97e8de3 OH	380	((attr->ia_valid & ATTR_MODE) &&
9c0aa1b8	381	(attr->ia_mode & ~FAT_VALID_MODE)))
1278fdd3 OH	382	error = -EPERM;
	383
	384	if (error) {
	385	if (sbi->options.quiet)
	386	error = 0;
	387	goto out;
	388	}
	389
2d518f84 OH	390	/*
	391	* We don't return -EPERM here. Yes, strange, but this is too
	392	* old behavior.
	393	*/
	394	if (attr->ia_valid & ATTR_MODE) {
	395	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	396	attr->ia_valid &= ~ATTR_MODE;
	397	}
1278fdd3	398
dfc209c0 OH	399	if (attr->ia_valid)
dfc209c0 OH	400	error = inode_setattr(inode, attr);
1278fdd3	401	out:
1278fdd3 OH	402	return error;
	403	}
	404	EXPORT_SYMBOL_GPL(fat_setattr);
	405
754661f1	406	const struct inode_operations fat_file_inode_operations = {
1da177e4	407	.truncate = fat_truncate,
1278fdd3	408	.setattr = fat_setattr,
da63fc7c	409	.getattr = fat_getattr,
1da177e4	410	};