[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/compat.h>
#include <linux/mount.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.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_inode(file);
	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;

	err = mnt_want_write_file(file);
	if (err)
		goto out;
	mutex_lock(&inode->i_mutex);

	/*
	 * 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_unlock_inode;
	}

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

	/*
	 * 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_unlock_inode;

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

	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_unlock_inode:
	mutex_unlock(&inode->i_mutex);
	mnt_drop_write_file(file);
out:
	return err;
}

static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr)
{
	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	return put_user(sbi->vol_id, user_attr);
}

long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct inode *inode = file_inode(filp);
	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);
	case FAT_IOCTL_GET_VOLUME_ID:
		return fat_ioctl_get_volume_id(inode, user_attr);
	default:
		return -ENOTTY;	/* Inappropriate ioctl for device */
	}
}

#ifdef CONFIG_COMPAT
static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
				      unsigned long arg)

{
	return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
}
#endif

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, loff_t start, loff_t end, int datasync)
{
	struct inode *inode = filp->f_mapping->host;
	int res, err;

	res = generic_file_fsync(filp, start, end, 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_iter	= generic_file_read_iter,
	.write_iter	= generic_file_write_iter,
	.mmap		= generic_file_mmap,
	.release	= fat_file_release,
	.unlocked_ioctl	= fat_generic_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= fat_generic_compat_ioctl,
#endif
	.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)) {
		int err2;

		/*
		 * Opencode syncing since we don't have a file open to use
		 * standard fsync path.
		 */
		err = filemap_fdatawrite_range(mapping, start,
					       start + count - 1);
		err2 = sync_mapping_buffers(mapping);
		if (!err)
			err = err2;
		err2 = write_inode_now(inode, 1);
		if (!err)
			err = err2;
		if (!err) {
			err =  filemap_fdatawait_range(mapping, start,
						       start + count - 1);
		}
	}
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_blocks(struct inode *inode, loff_t offset)
{
	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 > offset)
		MSDOS_I(inode)->mmu_private = offset;

	nr_clusters = (offset + (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 = d_inode(dentry);
	generic_fillattr(inode, stat);
	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;

	if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
		/* Use i_pos for ino. This is used as fileid of nfs. */
		stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
	}
	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)
{
	umode_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)
{
	umode_t allow_utime = sbi->options.allow_utime;

	if (!uid_eq(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 = d_inode(dentry);
	unsigned int ia_valid;
	int error;

	/* 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;
	}

	/*
	 * Expand the file. Since inode_setattr() updates ->i_size
	 * before calling the ->truncate(), but FAT needs to fill the
	 * hole before it. XXX: this is no longer true with new truncate
	 * sequence.
	 */
	if (attr->ia_valid & ATTR_SIZE) {
		inode_dio_wait(inode);

		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;
		}
	}

	if (((attr->ia_valid & ATTR_UID) &&
	     (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
	    ((attr->ia_valid & ATTR_GID) &&
	     (!gid_eq(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 & ATTR_SIZE) {
		error = fat_block_truncate_page(inode, attr->ia_size);
		if (error)
			goto out;
		down_write(&MSDOS_I(inode)->truncate_lock);
		truncate_setsize(inode, attr->ia_size);
		fat_truncate_blocks(inode, attr->ia_size);
		up_write(&MSDOS_I(inode)->truncate_lock);
	}

	setattr_copy(inode, attr);
	mark_inode_dirty(inode);
out:
	return error;
}
EXPORT_SYMBOL_GPL(fat_setattr);

const struct inode_operations fat_file_inode_operations = {
	.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>
7845bc3e	11	#include <linux/compat.h>
42a74f20	12	#include <linux/mount.h>
ae78bf9c	13	#include <linux/blkdev.h>
66114cad	14	#include <linux/backing-dev.h>
b1da47e2 MS	15	#include <linux/fsnotify.h>
b1da47e2 MS	16	#include <linux/security.h>
9e975dae	17	#include "fat.h"
1da177e4	18
21bea495 CH	19	static int fat_ioctl_get_attributes(struct inode inode, u32 __user user_attr)
	20	{
	21	u32 attr;
	22
	23	mutex_lock(&inode->i_mutex);
	24	attr = fat_make_attrs(inode);
	25	mutex_unlock(&inode->i_mutex);
	26
	27	return put_user(attr, user_attr);
	28	}
	29
	30	static int fat_ioctl_set_attributes(struct file file, u32 __user user_attr)
1da177e4	31	{
496ad9aa	32	struct inode *inode = file_inode(file);
1da177e4	33	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
21bea495 CH	34	int is_dir = S_ISDIR(inode->i_mode);
	35	u32 attr, oldattr;
	36	struct iattr ia;
	37	int err;
1da177e4	38
21bea495 CH	39	err = get_user(attr, user_attr);
	40	if (err)
	41	goto out;
1da177e4	42
a561be71	43	err = mnt_want_write_file(file);
21bea495	44	if (err)
e24f17da JK	45	goto out;
e24f17da JK	46	mutex_lock(&inode->i_mutex);
21bea495 CH	47
	48	/*
	49	* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
	50	* prevents the user from turning us into a VFAT
	51	* longname entry. Also, we obviously can't set
	52	* any of the NTFS attributes in the high 24 bits.
	53	*/
	54	attr &= 0xff & ~(ATTR_VOLUME \| ATTR_DIR);
	55	/* Merge in ATTR_VOLUME and ATTR_DIR */
	56	attr \|= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) \|
	57	(is_dir ? ATTR_DIR : 0);
	58	oldattr = fat_make_attrs(inode);
	59
	60	/* Equivalent to a chmod() */
	61	ia.ia_valid = ATTR_MODE \| ATTR_CTIME;
	62	ia.ia_ctime = current_fs_time(inode->i_sb);
	63	if (is_dir)
	64	ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
	65	else {
	66	ia.ia_mode = fat_make_mode(sbi, attr,
	67	S_IRUGO \| S_IWUGO \| (inode->i_mode & S_IXUGO));
	68	}
1da177e4	69
21bea495 CH	70	/* The root directory has no attributes */
	71	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
	72	err = -EINVAL;
e24f17da	73	goto out_unlock_inode;
1da177e4	74	}
1da177e4	75
21bea495 CH	76	if (sbi->options.sys_immutable &&
	77	((attr \| oldattr) & ATTR_SYS) &&
	78	!capable(CAP_LINUX_IMMUTABLE)) {
	79	err = -EPERM;
e24f17da	80	goto out_unlock_inode;
21bea495	81	}
1da177e4	82
21bea495 CH	83	/*
	84	* The security check is questionable... We single
	85	* out the RO attribute for checking by the security
	86	* module, just because it maps to a file mode.
	87	*/
	88	err = security_inode_setattr(file->f_path.dentry, &ia);
	89	if (err)
e24f17da	90	goto out_unlock_inode;
1da177e4	91
21bea495 CH	92	/* This MUST be done before doing anything irreversible... */
	93	err = fat_setattr(file->f_path.dentry, &ia);
	94	if (err)
e24f17da	95	goto out_unlock_inode;
21bea495 CH	96
	97	fsnotify_change(file->f_path.dentry, ia.ia_valid);
	98	if (sbi->options.sys_immutable) {
	99	if (attr & ATTR_SYS)
	100	inode->i_flags \|= S_IMMUTABLE;
	101	else
1adffbae	102	inode->i_flags &= ~S_IMMUTABLE;
21bea495	103	}
1da177e4	104
21bea495 CH	105	fat_save_attrs(inode, attr);
21bea495 CH	106	mark_inode_dirty(inode);
21bea495 CH	107	out_unlock_inode:
21bea495 CH	108	mutex_unlock(&inode->i_mutex);
e24f17da	109	mnt_drop_write_file(file);
21bea495 CH	110	out:
	111	return err;
	112	}
1da177e4	113
6e5b93ee ML	114	static int fat_ioctl_get_volume_id(struct inode inode, u32 __user user_attr)
	115	{
	116	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	117	return put_user(sbi->vol_id, user_attr);
	118	}
	119
7845bc3e	120	long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4	121	{
496ad9aa	122	struct inode *inode = file_inode(filp);
1da177e4	123	u32 __user user_attr = (u32 __user )arg;
1da177e4	124
1da177e4 LT	125	switch (cmd) {
1da177e4 LT	126	case FAT_IOCTL_GET_ATTRIBUTES:
21bea495	127	return fat_ioctl_get_attributes(inode, user_attr);
1da177e4	128	case FAT_IOCTL_SET_ATTRIBUTES:
21bea495	129	return fat_ioctl_set_attributes(filp, user_attr);
6e5b93ee ML	130	case FAT_IOCTL_GET_VOLUME_ID:
6e5b93ee ML	131	return fat_ioctl_get_volume_id(inode, user_attr);
1da177e4 LT	132	default:
	133	return -ENOTTY; /* Inappropriate ioctl for device */
	134	}
	135	}
	136
7845bc3e AB	137	#ifdef CONFIG_COMPAT
	138	static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
	139	unsigned long arg)
	140
	141	{
	142	return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
	143	}
	144	#endif
	145
ae78bf9c CM	146	static int fat_file_release(struct inode inode, struct file filp)
	147	{
	148	if ((filp->f_mode & FMODE_WRITE) &&
	149	MSDOS_SB(inode->i_sb)->options.flush) {
	150	fat_flush_inodes(inode->i_sb, inode, NULL);
8aa7e847	151	congestion_wait(BLK_RW_ASYNC, HZ/10);
ae78bf9c CM	152	}
	153	return 0;
	154	}
	155
02c24a82	156	int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
b522412a	157	{
7ea80859	158	struct inode *inode = filp->f_mapping->host;
b522412a AV	159	int res, err;
b522412a AV	160
02c24a82	161	res = generic_file_fsync(filp, start, end, datasync);
b522412a AV	162	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
	163
	164	return res ? res : err;
	165	}
	166
	167
4b6f5d20	168	const struct file_operations fat_file_operations = {
1da177e4	169	.llseek = generic_file_llseek,
aad4f8bb	170	.read_iter = generic_file_read_iter,
8174202b	171	.write_iter = generic_file_write_iter,
1da177e4	172	.mmap = generic_file_mmap,
ae78bf9c	173	.release = fat_file_release,
7845bc3e AB	174	.unlocked_ioctl = fat_generic_ioctl,
	175	#ifdef CONFIG_COMPAT
	176	.compat_ioctl = fat_generic_compat_ioctl,
	177	#endif
b522412a	178	.fsync = fat_file_fsync,
5ffc4ef4	179	.splice_read = generic_file_splice_read,
1da177e4 LT	180	};
1da177e4 LT	181
05eb0b51 OH	182	static int fat_cont_expand(struct inode *inode, loff_t size)
	183	{
	184	struct address_space *mapping = inode->i_mapping;
	185	loff_t start = inode->i_size, count = size - inode->i_size;
	186	int err;
	187
	188	err = generic_cont_expand_simple(inode, size);
	189	if (err)
	190	goto out;
	191
	192	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	193	mark_inode_dirty(inode);
2f3d675b JK	194	if (IS_SYNC(inode)) {
	195	int err2;
	196
	197	/*
	198	* Opencode syncing since we don't have a file open to use
	199	* standard fsync path.
	200	*/
	201	err = filemap_fdatawrite_range(mapping, start,
	202	start + count - 1);
	203	err2 = sync_mapping_buffers(mapping);
	204	if (!err)
	205	err = err2;
	206	err2 = write_inode_now(inode, 1);
	207	if (!err)
	208	err = err2;
	209	if (!err) {
	210	err = filemap_fdatawait_range(mapping, start,
	211	start + count - 1);
	212	}
	213	}
05eb0b51 OH	214	out:
	215	return err;
	216	}
	217
1da177e4 LT	218	/* Free all clusters after the skip'th cluster. */
	219	static int fat_free(struct inode *inode, int skip)
	220	{
	221	struct super_block *sb = inode->i_sb;
	222	int err, wait, free_start, i_start, i_logstart;
	223
	224	if (MSDOS_I(inode)->i_start == 0)
	225	return 0;
	226
3b641407 OH	227	fat_cache_inval_inode(inode);
3b641407 OH	228
1da177e4	229	wait = IS_DIRSYNC(inode);
3b641407 OH	230	i_start = free_start = MSDOS_I(inode)->i_start;
	231	i_logstart = MSDOS_I(inode)->i_logstart;
	232
	233	/* First, we write the new file size. */
	234	if (!skip) {
	235	MSDOS_I(inode)->i_start = 0;
	236	MSDOS_I(inode)->i_logstart = 0;
	237	}
	238	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
	239	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	240	if (wait) {
	241	err = fat_sync_inode(inode);
	242	if (err) {
	243	MSDOS_I(inode)->i_start = i_start;
	244	MSDOS_I(inode)->i_logstart = i_logstart;
	245	return err;
	246	}
	247	} else
	248	mark_inode_dirty(inode);
	249
	250	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	251	if (skip) {
	252	struct fat_entry fatent;
	253	int ret, fclus, dclus;
	254
	255	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	256	if (ret < 0)
	257	return ret;
	258	else if (ret == FAT_ENT_EOF)
	259	return 0;
	260
	261	fatent_init(&fatent);
	262	ret = fat_ent_read(inode, &fatent, dclus);
	263	if (ret == FAT_ENT_EOF) {
	264	fatent_brelse(&fatent);
	265	return 0;
	266	} else if (ret == FAT_ENT_FREE) {
85c78591	267	fat_fs_error(sb,
1da177e4	268	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	269	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	270	ret = -EIO;
	271	} else if (ret > 0) {
	272	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	273	if (err)
	274	ret = err;
	275	}
	276	fatent_brelse(&fatent);
	277	if (ret < 0)
	278	return ret;
	279
	280	free_start = ret;
1da177e4	281	}
1da177e4 LT	282	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	283
	284	/* Freeing the remained cluster chain */
	285	return fat_free_clusters(inode, free_start);
1da177e4 LT	286	}
1da177e4 LT	287
459f6ed3	288	void fat_truncate_blocks(struct inode *inode, loff_t offset)
1da177e4	289	{
9c20616c	290	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	291	const unsigned int cluster_size = sbi->cluster_size;
	292	int nr_clusters;
	293
	294	/*
	295	* This protects against truncating a file bigger than it was then
	296	* trying to write into the hole.
	297	*/
459f6ed3 NP	298	if (MSDOS_I(inode)->mmu_private > offset)
459f6ed3 NP	299	MSDOS_I(inode)->mmu_private = offset;
1da177e4	300
459f6ed3	301	nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
1da177e4	302
1da177e4	303	fat_free(inode, nr_clusters);
ae78bf9c	304	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	305	}
1da177e4 LT	306
da63fc7c OH	307	int fat_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat)
da63fc7c OH	308	{
2b0143b5	309	struct inode *inode = d_inode(dentry);
da63fc7c OH	310	generic_fillattr(inode, stat);
da63fc7c OH	311	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
ea3983ac NJ	312
	313	if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
	314	/* Use i_pos for ino. This is used as fileid of nfs. */
	315	stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
	316	}
da63fc7c OH	317	return 0;
	318	}
	319	EXPORT_SYMBOL_GPL(fat_getattr);
	320
2d518f84 OH	321	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	322	struct inode inode, umode_t mode_ptr)
1278fdd3	323	{
dacd0e7b	324	umode_t mask, perm;
1278fdd3	325
2d518f84 OH	326	/*
2d518f84 OH	327	* Note, the basic check is already done by a caller of
9c0aa1b8	328	* (attr->ia_mode & ~FAT_VALID_MODE)
2d518f84 OH	329	*/
	330
	331	if (S_ISREG(inode->i_mode))
1278fdd3 OH	332	mask = sbi->options.fs_fmask;
	333	else
	334	mask = sbi->options.fs_dmask;
	335
2d518f84 OH	336	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	337
1278fdd3 OH	338	/*
	339	* Of the r and x bits, all (subject to umask) must be present. Of the
	340	* w bits, either all (subject to umask) or none must be present.
dfc209c0 OH	341	*
dfc209c0 OH	342	* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
1278fdd3	343	*/
2d518f84	344	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	345	return -EPERM;
dfc209c0 OH	346	if (fat_mode_can_hold_ro(inode)) {
	347	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
	348	return -EPERM;
	349	} else {
	350	if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
	351	return -EPERM;
	352	}
1278fdd3	353
2d518f84 OH	354	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	355
1278fdd3 OH	356	return 0;
	357	}
	358
1ae43f82 OH	359	static int fat_allow_set_time(struct msdos_sb_info sbi, struct inode inode)
1ae43f82 OH	360	{
dacd0e7b	361	umode_t allow_utime = sbi->options.allow_utime;
1ae43f82	362
170782eb	363	if (!uid_eq(current_fsuid(), inode->i_uid)) {
1ae43f82 OH	364	if (in_group_p(inode->i_gid))
	365	allow_utime >>= 3;
	366	if (allow_utime & MAY_WRITE)
	367	return 1;
	368	}
	369
	370	/* use a default check */
	371	return 0;
	372	}
	373
17263849	374	#define TIMES_SET_FLAGS (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)
9c0aa1b8 OH	375	/* valid file mode bits */
9c0aa1b8 OH	376	#define FAT_VALID_MODE (S_IFREG \| S_IFDIR \| S_IRWXUGO)
17263849	377
1278fdd3 OH	378	int fat_setattr(struct dentry dentry, struct iattr attr)
	379	{
	380	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
2b0143b5	381	struct inode *inode = d_inode(dentry);
1ae43f82	382	unsigned int ia_valid;
dfc209c0	383	int error;
1278fdd3	384
1ae43f82 OH	385	/* Check for setting the inode time. */
1ae43f82 OH	386	ia_valid = attr->ia_valid;
17263849	387	if (ia_valid & TIMES_SET_FLAGS) {
1ae43f82	388	if (fat_allow_set_time(sbi, inode))
17263849	389	attr->ia_valid &= ~TIMES_SET_FLAGS;
1ae43f82 OH	390	}
1ae43f82 OH	391
1278fdd3	392	error = inode_change_ok(inode, attr);
1ae43f82	393	attr->ia_valid = ia_valid;
1278fdd3 OH	394	if (error) {
	395	if (sbi->options.quiet)
	396	error = 0;
	397	goto out;
	398	}
2d518f84	399
db78b877 CH	400	/*
	401	* Expand the file. Since inode_setattr() updates ->i_size
	402	* before calling the ->truncate(), but FAT needs to fill the
	403	* hole before it. XXX: this is no longer true with new truncate
	404	* sequence.
	405	*/
	406	if (attr->ia_valid & ATTR_SIZE) {
562c72aa CH	407	inode_dio_wait(inode);
562c72aa CH	408
db78b877 CH	409	if (attr->ia_size > inode->i_size) {
	410	error = fat_cont_expand(inode, attr->ia_size);
	411	if (error \|\| attr->ia_valid == ATTR_SIZE)
	412	goto out;
	413	attr->ia_valid &= ~ATTR_SIZE;
	414	}
	415	}
	416
1278fdd3	417	if (((attr->ia_valid & ATTR_UID) &&
170782eb	418	(!uid_eq(attr->ia_uid, sbi->options.fs_uid))) \|\|
1278fdd3	419	((attr->ia_valid & ATTR_GID) &&
170782eb	420	(!gid_eq(attr->ia_gid, sbi->options.fs_gid))) \|\|
e97e8de3	421	((attr->ia_valid & ATTR_MODE) &&
9c0aa1b8	422	(attr->ia_mode & ~FAT_VALID_MODE)))
1278fdd3 OH	423	error = -EPERM;
	424
	425	if (error) {
	426	if (sbi->options.quiet)
	427	error = 0;
	428	goto out;
	429	}
	430
2d518f84 OH	431	/*
	432	* We don't return -EPERM here. Yes, strange, but this is too
	433	* old behavior.
	434	*/
	435	if (attr->ia_valid & ATTR_MODE) {
	436	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	437	attr->ia_valid &= ~ATTR_MODE;
	438	}
1278fdd3	439
459f6ed3	440	if (attr->ia_valid & ATTR_SIZE) {
c0ef0cc9 NJ	441	error = fat_block_truncate_page(inode, attr->ia_size);
	442	if (error)
	443	goto out;
58268691	444	down_write(&MSDOS_I(inode)->truncate_lock);
2c27c65e CH	445	truncate_setsize(inode, attr->ia_size);
2c27c65e CH	446	fat_truncate_blocks(inode, attr->ia_size);
58268691	447	up_write(&MSDOS_I(inode)->truncate_lock);
459f6ed3 NP	448	}
459f6ed3 NP	449
6a1a90ad	450	setattr_copy(inode, attr);
459f6ed3	451	mark_inode_dirty(inode);
1278fdd3	452	out:
1278fdd3 OH	453	return error;
	454	}
	455	EXPORT_SYMBOL_GPL(fat_setattr);
	456
754661f1	457	const struct inode_operations fat_file_inode_operations = {
1278fdd3	458	.setattr = fat_setattr,
da63fc7c	459	.getattr = fat_getattr,
1da177e4	460	};