[linux-2.6-block.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/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>
b1da47e2 MS	14	#include <linux/fsnotify.h>
b1da47e2 MS	15	#include <linux/security.h>
9e975dae	16	#include "fat.h"
1da177e4	17
21bea495 CH	18	static int fat_ioctl_get_attributes(struct inode inode, u32 __user user_attr)
	19	{
	20	u32 attr;
	21
	22	mutex_lock(&inode->i_mutex);
	23	attr = fat_make_attrs(inode);
	24	mutex_unlock(&inode->i_mutex);
	25
	26	return put_user(attr, user_attr);
	27	}
	28
	29	static int fat_ioctl_set_attributes(struct file file, u32 __user user_attr)
1da177e4	30	{
496ad9aa	31	struct inode *inode = file_inode(file);
1da177e4	32	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
21bea495 CH	33	int is_dir = S_ISDIR(inode->i_mode);
	34	u32 attr, oldattr;
	35	struct iattr ia;
	36	int err;
1da177e4	37
21bea495 CH	38	err = get_user(attr, user_attr);
	39	if (err)
	40	goto out;
1da177e4	41
a561be71	42	err = mnt_want_write_file(file);
21bea495	43	if (err)
e24f17da JK	44	goto out;
e24f17da JK	45	mutex_lock(&inode->i_mutex);
21bea495 CH	46
	47	/*
	48	* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
	49	* prevents the user from turning us into a VFAT
	50	* longname entry. Also, we obviously can't set
	51	* any of the NTFS attributes in the high 24 bits.
	52	*/
	53	attr &= 0xff & ~(ATTR_VOLUME \| ATTR_DIR);
	54	/* Merge in ATTR_VOLUME and ATTR_DIR */
	55	attr \|= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) \|
	56	(is_dir ? ATTR_DIR : 0);
	57	oldattr = fat_make_attrs(inode);
	58
	59	/* Equivalent to a chmod() */
	60	ia.ia_valid = ATTR_MODE \| ATTR_CTIME;
	61	ia.ia_ctime = current_fs_time(inode->i_sb);
	62	if (is_dir)
	63	ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
	64	else {
	65	ia.ia_mode = fat_make_mode(sbi, attr,
	66	S_IRUGO \| S_IWUGO \| (inode->i_mode & S_IXUGO));
	67	}
1da177e4	68
21bea495 CH	69	/* The root directory has no attributes */
	70	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
	71	err = -EINVAL;
e24f17da	72	goto out_unlock_inode;
1da177e4	73	}
1da177e4	74
21bea495 CH	75	if (sbi->options.sys_immutable &&
	76	((attr \| oldattr) & ATTR_SYS) &&
	77	!capable(CAP_LINUX_IMMUTABLE)) {
	78	err = -EPERM;
e24f17da	79	goto out_unlock_inode;
21bea495	80	}
1da177e4	81
21bea495 CH	82	/*
	83	* The security check is questionable... We single
	84	* out the RO attribute for checking by the security
	85	* module, just because it maps to a file mode.
	86	*/
	87	err = security_inode_setattr(file->f_path.dentry, &ia);
	88	if (err)
e24f17da	89	goto out_unlock_inode;
1da177e4	90
21bea495 CH	91	/* This MUST be done before doing anything irreversible... */
	92	err = fat_setattr(file->f_path.dentry, &ia);
	93	if (err)
e24f17da	94	goto out_unlock_inode;
21bea495 CH	95
	96	fsnotify_change(file->f_path.dentry, ia.ia_valid);
	97	if (sbi->options.sys_immutable) {
	98	if (attr & ATTR_SYS)
	99	inode->i_flags \|= S_IMMUTABLE;
	100	else
1adffbae	101	inode->i_flags &= ~S_IMMUTABLE;
21bea495	102	}
1da177e4	103
21bea495 CH	104	fat_save_attrs(inode, attr);
21bea495 CH	105	mark_inode_dirty(inode);
21bea495 CH	106	out_unlock_inode:
21bea495 CH	107	mutex_unlock(&inode->i_mutex);
e24f17da	108	mnt_drop_write_file(file);
21bea495 CH	109	out:
	110	return err;
	111	}
1da177e4	112
6e5b93ee ML	113	static int fat_ioctl_get_volume_id(struct inode inode, u32 __user user_attr)
	114	{
	115	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	116	return put_user(sbi->vol_id, user_attr);
	117	}
	118
7845bc3e	119	long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4	120	{
496ad9aa	121	struct inode *inode = file_inode(filp);
1da177e4	122	u32 __user user_attr = (u32 __user )arg;
1da177e4	123
1da177e4 LT	124	switch (cmd) {
1da177e4 LT	125	case FAT_IOCTL_GET_ATTRIBUTES:
21bea495	126	return fat_ioctl_get_attributes(inode, user_attr);
1da177e4	127	case FAT_IOCTL_SET_ATTRIBUTES:
21bea495	128	return fat_ioctl_set_attributes(filp, user_attr);
6e5b93ee ML	129	case FAT_IOCTL_GET_VOLUME_ID:
6e5b93ee ML	130	return fat_ioctl_get_volume_id(inode, user_attr);
1da177e4 LT	131	default:
	132	return -ENOTTY; /* Inappropriate ioctl for device */
	133	}
	134	}
	135
7845bc3e AB	136	#ifdef CONFIG_COMPAT
	137	static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
	138	unsigned long arg)
	139
	140	{
	141	return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
	142	}
	143	#endif
	144
ae78bf9c CM	145	static int fat_file_release(struct inode inode, struct file filp)
	146	{
	147	if ((filp->f_mode & FMODE_WRITE) &&
	148	MSDOS_SB(inode->i_sb)->options.flush) {
	149	fat_flush_inodes(inode->i_sb, inode, NULL);
8aa7e847	150	congestion_wait(BLK_RW_ASYNC, HZ/10);
ae78bf9c CM	151	}
	152	return 0;
	153	}
	154
02c24a82	155	int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
b522412a	156	{
7ea80859	157	struct inode *inode = filp->f_mapping->host;
b522412a AV	158	int res, err;
b522412a AV	159
02c24a82	160	res = generic_file_fsync(filp, start, end, datasync);
b522412a AV	161	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
	162
	163	return res ? res : err;
	164	}
	165
	166
4b6f5d20	167	const struct file_operations fat_file_operations = {
1da177e4	168	.llseek = generic_file_llseek,
aad4f8bb	169	.read_iter = generic_file_read_iter,
8174202b	170	.write_iter = generic_file_write_iter,
1da177e4	171	.mmap = generic_file_mmap,
ae78bf9c	172	.release = fat_file_release,
7845bc3e AB	173	.unlocked_ioctl = fat_generic_ioctl,
	174	#ifdef CONFIG_COMPAT
	175	.compat_ioctl = fat_generic_compat_ioctl,
	176	#endif
b522412a	177	.fsync = fat_file_fsync,
5ffc4ef4	178	.splice_read = generic_file_splice_read,
1da177e4 LT	179	};
1da177e4 LT	180
05eb0b51 OH	181	static int fat_cont_expand(struct inode *inode, loff_t size)
	182	{
	183	struct address_space *mapping = inode->i_mapping;
	184	loff_t start = inode->i_size, count = size - inode->i_size;
	185	int err;
	186
	187	err = generic_cont_expand_simple(inode, size);
	188	if (err)
	189	goto out;
	190
	191	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	192	mark_inode_dirty(inode);
2f3d675b JK	193	if (IS_SYNC(inode)) {
	194	int err2;
	195
	196	/*
	197	* Opencode syncing since we don't have a file open to use
	198	* standard fsync path.
	199	*/
	200	err = filemap_fdatawrite_range(mapping, start,
	201	start + count - 1);
	202	err2 = sync_mapping_buffers(mapping);
	203	if (!err)
	204	err = err2;
	205	err2 = write_inode_now(inode, 1);
	206	if (!err)
	207	err = err2;
	208	if (!err) {
	209	err = filemap_fdatawait_range(mapping, start,
	210	start + count - 1);
	211	}
	212	}
05eb0b51 OH	213	out:
	214	return err;
	215	}
	216
1da177e4 LT	217	/* Free all clusters after the skip'th cluster. */
	218	static int fat_free(struct inode *inode, int skip)
	219	{
	220	struct super_block *sb = inode->i_sb;
	221	int err, wait, free_start, i_start, i_logstart;
	222
	223	if (MSDOS_I(inode)->i_start == 0)
	224	return 0;
	225
3b641407 OH	226	fat_cache_inval_inode(inode);
3b641407 OH	227
1da177e4	228	wait = IS_DIRSYNC(inode);
3b641407 OH	229	i_start = free_start = MSDOS_I(inode)->i_start;
	230	i_logstart = MSDOS_I(inode)->i_logstart;
	231
	232	/* First, we write the new file size. */
	233	if (!skip) {
	234	MSDOS_I(inode)->i_start = 0;
	235	MSDOS_I(inode)->i_logstart = 0;
	236	}
	237	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
	238	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	239	if (wait) {
	240	err = fat_sync_inode(inode);
	241	if (err) {
	242	MSDOS_I(inode)->i_start = i_start;
	243	MSDOS_I(inode)->i_logstart = i_logstart;
	244	return err;
	245	}
	246	} else
	247	mark_inode_dirty(inode);
	248
	249	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	250	if (skip) {
	251	struct fat_entry fatent;
	252	int ret, fclus, dclus;
	253
	254	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	255	if (ret < 0)
	256	return ret;
	257	else if (ret == FAT_ENT_EOF)
	258	return 0;
	259
	260	fatent_init(&fatent);
	261	ret = fat_ent_read(inode, &fatent, dclus);
	262	if (ret == FAT_ENT_EOF) {
	263	fatent_brelse(&fatent);
	264	return 0;
	265	} else if (ret == FAT_ENT_FREE) {
85c78591	266	fat_fs_error(sb,
1da177e4	267	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	268	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	269	ret = -EIO;
	270	} else if (ret > 0) {
	271	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	272	if (err)
	273	ret = err;
	274	}
	275	fatent_brelse(&fatent);
	276	if (ret < 0)
	277	return ret;
	278
	279	free_start = ret;
1da177e4	280	}
1da177e4 LT	281	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	282
	283	/* Freeing the remained cluster chain */
	284	return fat_free_clusters(inode, free_start);
1da177e4 LT	285	}
1da177e4 LT	286
459f6ed3	287	void fat_truncate_blocks(struct inode *inode, loff_t offset)
1da177e4	288	{
9c20616c	289	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	290	const unsigned int cluster_size = sbi->cluster_size;
	291	int nr_clusters;
	292
	293	/*
	294	* This protects against truncating a file bigger than it was then
	295	* trying to write into the hole.
	296	*/
459f6ed3	297	if (MSDOS_I(inode)->mmu_private > offset)
459f6ed3	298	MSDOS_I(inode)->mmu_private = offset;
1da177e4	299
459f6ed3	300	nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
1da177e4	301
1da177e4	302	fat_free(inode, nr_clusters);
ae78bf9c	303	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	304	}
1da177e4 LT	305
da63fc7c OH	306	int fat_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat)
da63fc7c OH	307	{
2b0143b5	308	struct inode *inode = d_inode(dentry);
da63fc7c OH	309	generic_fillattr(inode, stat);
da63fc7c OH	310	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
ea3983ac NJ	311
	312	if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
	313	/* Use i_pos for ino. This is used as fileid of nfs. */
	314	stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
	315	}
da63fc7c OH	316	return 0;
	317	}
	318	EXPORT_SYMBOL_GPL(fat_getattr);
	319
2d518f84 OH	320	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	321	struct inode inode, umode_t mode_ptr)
1278fdd3	322	{
dacd0e7b	323	umode_t mask, perm;
1278fdd3	324
2d518f84 OH	325	/*
2d518f84 OH	326	* Note, the basic check is already done by a caller of
9c0aa1b8	327	* (attr->ia_mode & ~FAT_VALID_MODE)
2d518f84 OH	328	*/
	329
	330	if (S_ISREG(inode->i_mode))
1278fdd3 OH	331	mask = sbi->options.fs_fmask;
	332	else
	333	mask = sbi->options.fs_dmask;
	334
2d518f84 OH	335	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	336
1278fdd3 OH	337	/*
	338	* Of the r and x bits, all (subject to umask) must be present. Of the
	339	* w bits, either all (subject to umask) or none must be present.
dfc209c0 OH	340	*
dfc209c0 OH	341	* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
1278fdd3	342	*/
2d518f84	343	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	344	return -EPERM;
dfc209c0 OH	345	if (fat_mode_can_hold_ro(inode)) {
	346	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
	347	return -EPERM;
	348	} else {
	349	if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
	350	return -EPERM;
	351	}
1278fdd3	352
2d518f84 OH	353	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	354
1278fdd3 OH	355	return 0;
	356	}
	357
1ae43f82 OH	358	static int fat_allow_set_time(struct msdos_sb_info sbi, struct inode inode)
1ae43f82 OH	359	{
dacd0e7b	360	umode_t allow_utime = sbi->options.allow_utime;
1ae43f82	361
170782eb	362	if (!uid_eq(current_fsuid(), inode->i_uid)) {
1ae43f82 OH	363	if (in_group_p(inode->i_gid))
	364	allow_utime >>= 3;
	365	if (allow_utime & MAY_WRITE)
	366	return 1;
	367	}
	368
	369	/* use a default check */
	370	return 0;
	371	}
	372
17263849	373	#define TIMES_SET_FLAGS (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)
9c0aa1b8 OH	374	/* valid file mode bits */
9c0aa1b8 OH	375	#define FAT_VALID_MODE (S_IFREG \| S_IFDIR \| S_IRWXUGO)
17263849	376
1278fdd3 OH	377	int fat_setattr(struct dentry dentry, struct iattr attr)
	378	{
	379	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
2b0143b5	380	struct inode *inode = d_inode(dentry);
1ae43f82	381	unsigned int ia_valid;
dfc209c0	382	int error;
1278fdd3	383
1ae43f82 OH	384	/* Check for setting the inode time. */
1ae43f82 OH	385	ia_valid = attr->ia_valid;
17263849	386	if (ia_valid & TIMES_SET_FLAGS) {
1ae43f82	387	if (fat_allow_set_time(sbi, inode))
17263849	388	attr->ia_valid &= ~TIMES_SET_FLAGS;
1ae43f82 OH	389	}
1ae43f82 OH	390
1278fdd3	391	error = inode_change_ok(inode, attr);
1ae43f82	392	attr->ia_valid = ia_valid;
1278fdd3 OH	393	if (error) {
	394	if (sbi->options.quiet)
	395	error = 0;
	396	goto out;
	397	}
2d518f84	398
db78b877 CH	399	/*
	400	* Expand the file. Since inode_setattr() updates ->i_size
	401	* before calling the ->truncate(), but FAT needs to fill the
	402	* hole before it. XXX: this is no longer true with new truncate
	403	* sequence.
	404	*/
	405	if (attr->ia_valid & ATTR_SIZE) {
562c72aa CH	406	inode_dio_wait(inode);
562c72aa CH	407
db78b877 CH	408	if (attr->ia_size > inode->i_size) {
	409	error = fat_cont_expand(inode, attr->ia_size);
	410	if (error \|\| attr->ia_valid == ATTR_SIZE)
	411	goto out;
	412	attr->ia_valid &= ~ATTR_SIZE;
	413	}
	414	}
	415
1278fdd3	416	if (((attr->ia_valid & ATTR_UID) &&
170782eb	417	(!uid_eq(attr->ia_uid, sbi->options.fs_uid))) \|\|
1278fdd3	418	((attr->ia_valid & ATTR_GID) &&
170782eb	419	(!gid_eq(attr->ia_gid, sbi->options.fs_gid))) \|\|
e97e8de3	420	((attr->ia_valid & ATTR_MODE) &&
9c0aa1b8	421	(attr->ia_mode & ~FAT_VALID_MODE)))
1278fdd3 OH	422	error = -EPERM;
	423
	424	if (error) {
	425	if (sbi->options.quiet)
	426	error = 0;
	427	goto out;
	428	}
	429
2d518f84 OH	430	/*
	431	* We don't return -EPERM here. Yes, strange, but this is too
	432	* old behavior.
	433	*/
	434	if (attr->ia_valid & ATTR_MODE) {
	435	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	436	attr->ia_valid &= ~ATTR_MODE;
	437	}
1278fdd3	438
459f6ed3	439	if (attr->ia_valid & ATTR_SIZE) {
c0ef0cc9 NJ	440	error = fat_block_truncate_page(inode, attr->ia_size);
	441	if (error)
	442	goto out;
58268691	443	down_write(&MSDOS_I(inode)->truncate_lock);
2c27c65e CH	444	truncate_setsize(inode, attr->ia_size);
2c27c65e CH	445	fat_truncate_blocks(inode, attr->ia_size);
58268691	446	up_write(&MSDOS_I(inode)->truncate_lock);
459f6ed3	447	}
459f6ed3	448
6a1a90ad	449	setattr_copy(inode, attr);
459f6ed3	450	mark_inode_dirty(inode);
1278fdd3	451	out:
1278fdd3 OH	452	return error;
	453	}
	454	EXPORT_SYMBOL_GPL(fat_setattr);
	455
754661f1	456	const struct inode_operations fat_file_inode_operations = {
1278fdd3	457	.setattr = fat_setattr,
da63fc7c	458	.getattr = fat_getattr,
1da177e4	459	};