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

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  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 <linux/falloc.h>
#include "fat.h"

static long fat_fallocate(struct file *file, int mode,
			  loff_t offset, loff_t len);

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

	inode_lock_shared(inode);
	attr = fat_make_attrs(inode);
	inode_unlock_shared(inode);

	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;
	inode_lock(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_time(inode);
	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_mnt_idmap(file),
				     file->f_path.dentry, &ia);
	if (err)
		goto out_unlock_inode;

	/* This MUST be done before doing anything irreversible... */
	err = fat_setattr(file_mnt_idmap(file), 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:
	inode_unlock(inode);
	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);
}

static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
{
	struct super_block *sb = inode->i_sb;
	struct fstrim_range __user *user_range;
	struct fstrim_range range;
	int err;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (!bdev_max_discard_sectors(sb->s_bdev))
		return -EOPNOTSUPP;

	user_range = (struct fstrim_range __user *)arg;
	if (copy_from_user(&range, user_range, sizeof(range)))
		return -EFAULT;

	range.minlen = max_t(unsigned int, range.minlen,
			     bdev_discard_granularity(sb->s_bdev));

	err = fat_trim_fs(inode, &range);
	if (err < 0)
		return err;

	if (copy_to_user(user_range, &range, sizeof(range)))
		return -EFAULT;

	return 0;
}

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);
	case FITRIM:
		return fat_ioctl_fitrim(inode, arg);
	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);
		set_current_state(TASK_UNINTERRUPTIBLE);
		io_schedule_timeout(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 err;

	err = __generic_file_fsync(filp, start, end, datasync);
	if (err)
		return err;

	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
	if (err)
		return err;

	return blkdev_issue_flush(inode->i_sb->s_bdev);
}


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,
	.compat_ioctl	= compat_ptr_ioctl,
	.fsync		= fat_file_fsync,
	.splice_read	= filemap_splice_read,
	.splice_write	= iter_file_splice_write,
	.fallocate	= fat_fallocate,
};

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;

	fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
	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;
}

/*
 * Preallocate space for a file. This implements fat's fallocate file
 * operation, which gets called from sys_fallocate system call. User
 * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
 * we just allocate clusters without zeroing them out. Otherwise we
 * allocate and zero out clusters via an expanding truncate.
 */
static long fat_fallocate(struct file *file, int mode,
			  loff_t offset, loff_t len)
{
	int nr_cluster; /* Number of clusters to be allocated */
	loff_t mm_bytes; /* Number of bytes to be allocated for file */
	loff_t ondisksize; /* block aligned on-disk size in bytes*/
	struct inode *inode = file->f_mapping->host;
	struct super_block *sb = inode->i_sb;
	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	int err = 0;

	/* No support for hole punch or other fallocate flags. */
	if (mode & ~FALLOC_FL_KEEP_SIZE)
		return -EOPNOTSUPP;

	/* No support for dir */
	if (!S_ISREG(inode->i_mode))
		return -EOPNOTSUPP;

	inode_lock(inode);
	if (mode & FALLOC_FL_KEEP_SIZE) {
		ondisksize = inode->i_blocks << 9;
		if ((offset + len) <= ondisksize)
			goto error;

		/* First compute the number of clusters to be allocated */
		mm_bytes = offset + len - ondisksize;
		nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
			sbi->cluster_bits;

		/* Start the allocation.We are not zeroing out the clusters */
		while (nr_cluster-- > 0) {
			err = fat_add_cluster(inode);
			if (err)
				goto error;
		}
	} else {
		if ((offset + len) <= i_size_read(inode))
			goto error;

		/* This is just an expanding truncate */
		err = fat_cont_expand(inode, (offset + len));
	}

error:
	inode_unlock(inode);
	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;
	fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
	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 mnt_idmap *idmap, const struct path *path,
		struct kstat *stat, u32 request_mask, unsigned int flags)
{
	struct inode *inode = d_inode(path->dentry);
	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);

	generic_fillattr(idmap, request_mask, inode, stat);
	stat->blksize = sbi->cluster_size;

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

	if (sbi->options.isvfat && request_mask & STATX_BTIME) {
		stat->result_mask |= STATX_BTIME;
		stat->btime = MSDOS_I(inode)->i_crtime;
	}

	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 mnt_idmap *idmap,
			      struct msdos_sb_info *sbi, struct inode *inode)
{
	umode_t allow_utime = sbi->options.allow_utime;

	if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
			    current_fsuid())) {
		if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
			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 mnt_idmap *idmap, 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(idmap, sbi, inode))
			attr->ia_valid &= ~TIMES_SET_FLAGS;
	}

	error = setattr_prepare(idmap, dentry, 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(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
		      sbi->options.fs_uid))) ||
	    ((attr->ia_valid & ATTR_GID) &&
	     (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
		      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 can't truncate these appropriately, so we'll
	 * copy them ourselves
	 */
	if (attr->ia_valid & ATTR_ATIME)
		fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
	if (attr->ia_valid & ATTR_CTIME)
		fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
	if (attr->ia_valid & ATTR_MTIME)
		fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
	attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);

	setattr_copy(idmap, 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,
	.update_time	= fat_update_time,
};
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
1da177e4 LT	2	/*
	3	* linux/fs/fat/file.c
	4	*
	5	* Written 1992,1993 by Werner Almesberger
	6	*
	7	* regular file handling primitives for fat-based filesystems
	8	*/
	9
16f7e0fe	10	#include <linux/capability.h>
1da177e4	11	#include <linux/module.h>
7845bc3e	12	#include <linux/compat.h>
42a74f20	13	#include <linux/mount.h>
ae78bf9c	14	#include <linux/blkdev.h>
66114cad	15	#include <linux/backing-dev.h>
b1da47e2 MS	16	#include <linux/fsnotify.h>
b1da47e2 MS	17	#include <linux/security.h>
b13bb33e	18	#include <linux/falloc.h>
9e975dae	19	#include "fat.h"
1da177e4	20
b13bb33e NJ	21	static long fat_fallocate(struct file *file, int mode,
	22	loff_t offset, loff_t len);
	23
21bea495 CH	24	static int fat_ioctl_get_attributes(struct inode inode, u32 __user user_attr)
	25	{
	26	u32 attr;
	27
e348e65a	28	inode_lock_shared(inode);
21bea495	29	attr = fat_make_attrs(inode);
e348e65a	30	inode_unlock_shared(inode);
21bea495 CH	31
	32	return put_user(attr, user_attr);
	33	}
	34
	35	static int fat_ioctl_set_attributes(struct file file, u32 __user user_attr)
1da177e4	36	{
496ad9aa	37	struct inode *inode = file_inode(file);
1da177e4	38	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
21bea495 CH	39	int is_dir = S_ISDIR(inode->i_mode);
	40	u32 attr, oldattr;
	41	struct iattr ia;
	42	int err;
1da177e4	43
21bea495 CH	44	err = get_user(attr, user_attr);
	45	if (err)
	46	goto out;
1da177e4	47
a561be71	48	err = mnt_want_write_file(file);
21bea495	49	if (err)
e24f17da	50	goto out;
5955102c	51	inode_lock(inode);
21bea495 CH	52
	53	/*
	54	* ATTR_VOLUME and ATTR_DIR cannot be changed; this also
	55	* prevents the user from turning us into a VFAT
	56	* longname entry. Also, we obviously can't set
	57	* any of the NTFS attributes in the high 24 bits.
	58	*/
	59	attr &= 0xff & ~(ATTR_VOLUME \| ATTR_DIR);
	60	/* Merge in ATTR_VOLUME and ATTR_DIR */
	61	attr \|= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) \|
	62	(is_dir ? ATTR_DIR : 0);
	63	oldattr = fat_make_attrs(inode);
	64
	65	/* Equivalent to a chmod() */
	66	ia.ia_valid = ATTR_MODE \| ATTR_CTIME;
c2050a45	67	ia.ia_ctime = current_time(inode);
21bea495 CH	68	if (is_dir)
	69	ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
	70	else {
	71	ia.ia_mode = fat_make_mode(sbi, attr,
	72	S_IRUGO \| S_IWUGO \| (inode->i_mode & S_IXUGO));
	73	}
1da177e4	74
21bea495 CH	75	/* The root directory has no attributes */
	76	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
	77	err = -EINVAL;
e24f17da	78	goto out_unlock_inode;
1da177e4	79	}
1da177e4	80
21bea495 CH	81	if (sbi->options.sys_immutable &&
	82	((attr \| oldattr) & ATTR_SYS) &&
	83	!capable(CAP_LINUX_IMMUTABLE)) {
	84	err = -EPERM;
e24f17da	85	goto out_unlock_inode;
21bea495	86	}
1da177e4	87
21bea495 CH	88	/*
	89	* The security check is questionable... We single
	90	* out the RO attribute for checking by the security
	91	* module, just because it maps to a file mode.
	92	*/
c1632a0f	93	err = security_inode_setattr(file_mnt_idmap(file),
0e363cf3	94	file->f_path.dentry, &ia);
21bea495	95	if (err)
e24f17da	96	goto out_unlock_inode;
1da177e4	97
21bea495	98	/* This MUST be done before doing anything irreversible... */
c1632a0f	99	err = fat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
21bea495	100	if (err)
e24f17da	101	goto out_unlock_inode;
21bea495 CH	102
	103	fsnotify_change(file->f_path.dentry, ia.ia_valid);
	104	if (sbi->options.sys_immutable) {
	105	if (attr & ATTR_SYS)
	106	inode->i_flags \|= S_IMMUTABLE;
	107	else
1adffbae	108	inode->i_flags &= ~S_IMMUTABLE;
21bea495	109	}
1da177e4	110
21bea495 CH	111	fat_save_attrs(inode, attr);
21bea495 CH	112	mark_inode_dirty(inode);
21bea495	113	out_unlock_inode:
5955102c	114	inode_unlock(inode);
e24f17da	115	mnt_drop_write_file(file);
21bea495 CH	116	out:
	117	return err;
	118	}
1da177e4	119
6e5b93ee ML	120	static int fat_ioctl_get_volume_id(struct inode inode, u32 __user user_attr)
	121	{
	122	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	123	return put_user(sbi->vol_id, user_attr);
	124	}
	125
f663b5b3 WW	126	static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
	127	{
	128	struct super_block *sb = inode->i_sb;
	129	struct fstrim_range __user *user_range;
	130	struct fstrim_range range;
f663b5b3 WW	131	int err;
	132
	133	if (!capable(CAP_SYS_ADMIN))
	134	return -EPERM;
	135
70200574	136	if (!bdev_max_discard_sectors(sb->s_bdev))
f663b5b3 WW	137	return -EOPNOTSUPP;
	138
	139	user_range = (struct fstrim_range __user *)arg;
	140	if (copy_from_user(&range, user_range, sizeof(range)))
	141	return -EFAULT;
	142
	143	range.minlen = max_t(unsigned int, range.minlen,
7b47ef52	144	bdev_discard_granularity(sb->s_bdev));
f663b5b3 WW	145
	146	err = fat_trim_fs(inode, &range);
	147	if (err < 0)
	148	return err;
	149
	150	if (copy_to_user(user_range, &range, sizeof(range)))
	151	return -EFAULT;
	152
	153	return 0;
	154	}
	155
7845bc3e	156	long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4	157	{
496ad9aa	158	struct inode *inode = file_inode(filp);
1da177e4	159	u32 __user user_attr = (u32 __user )arg;
1da177e4	160
1da177e4 LT	161	switch (cmd) {
1da177e4 LT	162	case FAT_IOCTL_GET_ATTRIBUTES:
21bea495	163	return fat_ioctl_get_attributes(inode, user_attr);
1da177e4	164	case FAT_IOCTL_SET_ATTRIBUTES:
21bea495	165	return fat_ioctl_set_attributes(filp, user_attr);
6e5b93ee ML	166	case FAT_IOCTL_GET_VOLUME_ID:
6e5b93ee ML	167	return fat_ioctl_get_volume_id(inode, user_attr);
f663b5b3 WW	168	case FITRIM:
f663b5b3 WW	169	return fat_ioctl_fitrim(inode, arg);
1da177e4 LT	170	default:
	171	return -ENOTTY; /* Inappropriate ioctl for device */
	172	}
	173	}
	174
ae78bf9c CM	175	static int fat_file_release(struct inode inode, struct file filp)
	176	{
	177	if ((filp->f_mode & FMODE_WRITE) &&
9bb56d59	178	MSDOS_SB(inode->i_sb)->options.flush) {
ae78bf9c	179	fat_flush_inodes(inode->i_sb, inode, NULL);
9bb56d59 N	180	set_current_state(TASK_UNINTERRUPTIBLE);
9bb56d59 N	181	io_schedule_timeout(HZ/10);
ae78bf9c CM	182	}
	183	return 0;
	184	}
	185
02c24a82	186	int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
b522412a	187	{
7ea80859	188	struct inode *inode = filp->f_mapping->host;
bd8309de HT	189	int err;
	190
	191	err = __generic_file_fsync(filp, start, end, datasync);
	192	if (err)
	193	return err;
b522412a	194
b522412a	195	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
bd8309de HT	196	if (err)
bd8309de HT	197	return err;
b522412a	198
c6bf3f0e	199	return blkdev_issue_flush(inode->i_sb->s_bdev);
b522412a AV	200	}
	201
	202
4b6f5d20	203	const struct file_operations fat_file_operations = {
1da177e4	204	.llseek = generic_file_llseek,
aad4f8bb	205	.read_iter = generic_file_read_iter,
8174202b	206	.write_iter = generic_file_write_iter,
1da177e4	207	.mmap = generic_file_mmap,
ae78bf9c	208	.release = fat_file_release,
7845bc3e	209	.unlocked_ioctl = fat_generic_ioctl,
407e9ef7	210	.compat_ioctl = compat_ptr_ioctl,
b522412a	211	.fsync = fat_file_fsync,
2cb1e089	212	.splice_read = filemap_splice_read,
67ceb1ec	213	.splice_write = iter_file_splice_write,
b13bb33e	214	.fallocate = fat_fallocate,
1da177e4 LT	215	};
1da177e4 LT	216
05eb0b51 OH	217	static int fat_cont_expand(struct inode *inode, loff_t size)
	218	{
	219	struct address_space *mapping = inode->i_mapping;
	220	loff_t start = inode->i_size, count = size - inode->i_size;
	221	int err;
	222
	223	err = generic_cont_expand_simple(inode, size);
	224	if (err)
	225	goto out;
	226
cd83f6b1	227	fat_truncate_time(inode, NULL, S_CTIME\|S_MTIME);
05eb0b51	228	mark_inode_dirty(inode);
2f3d675b JK	229	if (IS_SYNC(inode)) {
	230	int err2;
	231
	232	/*
	233	* Opencode syncing since we don't have a file open to use
	234	* standard fsync path.
	235	*/
	236	err = filemap_fdatawrite_range(mapping, start,
	237	start + count - 1);
	238	err2 = sync_mapping_buffers(mapping);
	239	if (!err)
	240	err = err2;
	241	err2 = write_inode_now(inode, 1);
	242	if (!err)
	243	err = err2;
	244	if (!err) {
	245	err = filemap_fdatawait_range(mapping, start,
	246	start + count - 1);
	247	}
	248	}
05eb0b51 OH	249	out:
	250	return err;
	251	}
	252
b13bb33e NJ	253	/*
	254	* Preallocate space for a file. This implements fat's fallocate file
	255	* operation, which gets called from sys_fallocate system call. User
	256	* space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
	257	* we just allocate clusters without zeroing them out. Otherwise we
	258	* allocate and zero out clusters via an expanding truncate.
	259	*/
	260	static long fat_fallocate(struct file *file, int mode,
	261	loff_t offset, loff_t len)
	262	{
	263	int nr_cluster; /* Number of clusters to be allocated */
	264	loff_t mm_bytes; /* Number of bytes to be allocated for file */
	265	loff_t ondisksize; /* block aligned on-disk size in bytes*/
	266	struct inode *inode = file->f_mapping->host;
	267	struct super_block *sb = inode->i_sb;
	268	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	269	int err = 0;
	270
	271	/* No support for hole punch or other fallocate flags. */
	272	if (mode & ~FALLOC_FL_KEEP_SIZE)
	273	return -EOPNOTSUPP;
	274
	275	/* No support for dir */
	276	if (!S_ISREG(inode->i_mode))
	277	return -EOPNOTSUPP;
	278
5955102c	279	inode_lock(inode);
b13bb33e NJ	280	if (mode & FALLOC_FL_KEEP_SIZE) {
	281	ondisksize = inode->i_blocks << 9;
	282	if ((offset + len) <= ondisksize)
	283	goto error;
	284
	285	/* First compute the number of clusters to be allocated */
	286	mm_bytes = offset + len - ondisksize;
	287	nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
	288	sbi->cluster_bits;
	289
	290	/* Start the allocation.We are not zeroing out the clusters */
	291	while (nr_cluster-- > 0) {
	292	err = fat_add_cluster(inode);
	293	if (err)
	294	goto error;
	295	}
	296	} else {
	297	if ((offset + len) <= i_size_read(inode))
	298	goto error;
	299
	300	/* This is just an expanding truncate */
	301	err = fat_cont_expand(inode, (offset + len));
	302	}
	303
	304	error:
5955102c	305	inode_unlock(inode);
b13bb33e NJ	306	return err;
	307	}
	308
1da177e4 LT	309	/* Free all clusters after the skip'th cluster. */
	310	static int fat_free(struct inode *inode, int skip)
	311	{
	312	struct super_block *sb = inode->i_sb;
	313	int err, wait, free_start, i_start, i_logstart;
	314
	315	if (MSDOS_I(inode)->i_start == 0)
	316	return 0;
	317
3b641407 OH	318	fat_cache_inval_inode(inode);
3b641407 OH	319
1da177e4	320	wait = IS_DIRSYNC(inode);
3b641407 OH	321	i_start = free_start = MSDOS_I(inode)->i_start;
	322	i_logstart = MSDOS_I(inode)->i_logstart;
	323
	324	/* First, we write the new file size. */
	325	if (!skip) {
	326	MSDOS_I(inode)->i_start = 0;
	327	MSDOS_I(inode)->i_logstart = 0;
	328	}
	329	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
cd83f6b1	330	fat_truncate_time(inode, NULL, S_CTIME\|S_MTIME);
3b641407 OH	331	if (wait) {
	332	err = fat_sync_inode(inode);
	333	if (err) {
	334	MSDOS_I(inode)->i_start = i_start;
	335	MSDOS_I(inode)->i_logstart = i_logstart;
	336	return err;
	337	}
	338	} else
	339	mark_inode_dirty(inode);
	340
	341	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	342	if (skip) {
	343	struct fat_entry fatent;
	344	int ret, fclus, dclus;
	345
	346	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	347	if (ret < 0)
	348	return ret;
	349	else if (ret == FAT_ENT_EOF)
	350	return 0;
	351
	352	fatent_init(&fatent);
	353	ret = fat_ent_read(inode, &fatent, dclus);
	354	if (ret == FAT_ENT_EOF) {
	355	fatent_brelse(&fatent);
	356	return 0;
	357	} else if (ret == FAT_ENT_FREE) {
85c78591	358	fat_fs_error(sb,
1da177e4	359	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	360	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	361	ret = -EIO;
	362	} else if (ret > 0) {
	363	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	364	if (err)
	365	ret = err;
	366	}
	367	fatent_brelse(&fatent);
	368	if (ret < 0)
	369	return ret;
	370
	371	free_start = ret;
1da177e4	372	}
1da177e4 LT	373	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	374
	375	/* Freeing the remained cluster chain */
	376	return fat_free_clusters(inode, free_start);
1da177e4 LT	377	}
1da177e4 LT	378
459f6ed3	379	void fat_truncate_blocks(struct inode *inode, loff_t offset)
1da177e4	380	{
9c20616c	381	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	382	const unsigned int cluster_size = sbi->cluster_size;
	383	int nr_clusters;
	384
	385	/*
	386	* This protects against truncating a file bigger than it was then
	387	* trying to write into the hole.
	388	*/
459f6ed3 NP	389	if (MSDOS_I(inode)->mmu_private > offset)
459f6ed3 NP	390	MSDOS_I(inode)->mmu_private = offset;
1da177e4	391
459f6ed3	392	nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
1da177e4	393
1da177e4	394	fat_free(inode, nr_clusters);
ae78bf9c	395	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	396	}
1da177e4 LT	397
b74d24f7	398	int fat_getattr(struct mnt_idmap idmap, const struct path path,
549c7297	399	struct kstat *stat, u32 request_mask, unsigned int flags)
da63fc7c	400	{
a528d35e	401	struct inode *inode = d_inode(path->dentry);
30abce05 CCC	402	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
30abce05 CCC	403
0d72b928	404	generic_fillattr(idmap, request_mask, inode, stat);
30abce05	405	stat->blksize = sbi->cluster_size;
ea3983ac	406
30abce05	407	if (sbi->options.nfs == FAT_NFS_NOSTALE_RO) {
ea3983ac	408	/* Use i_pos for ino. This is used as fileid of nfs. */
30abce05	409	stat->ino = fat_i_pos_read(sbi, inode);
ea3983ac	410	}
30abce05 CCC	411
	412	if (sbi->options.isvfat && request_mask & STATX_BTIME) {
	413	stat->result_mask \|= STATX_BTIME;
	414	stat->btime = MSDOS_I(inode)->i_crtime;
	415	}
	416
da63fc7c OH	417	return 0;
	418	}
	419	EXPORT_SYMBOL_GPL(fat_getattr);
	420
2d518f84 OH	421	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	422	struct inode inode, umode_t mode_ptr)
1278fdd3	423	{
dacd0e7b	424	umode_t mask, perm;
1278fdd3	425
2d518f84 OH	426	/*
2d518f84 OH	427	* Note, the basic check is already done by a caller of
9c0aa1b8	428	* (attr->ia_mode & ~FAT_VALID_MODE)
2d518f84 OH	429	*/
	430
	431	if (S_ISREG(inode->i_mode))
1278fdd3 OH	432	mask = sbi->options.fs_fmask;
	433	else
	434	mask = sbi->options.fs_dmask;
	435
2d518f84 OH	436	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	437
1278fdd3 OH	438	/*
	439	* Of the r and x bits, all (subject to umask) must be present. Of the
	440	* w bits, either all (subject to umask) or none must be present.
dfc209c0 OH	441	*
dfc209c0 OH	442	* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
1278fdd3	443	*/
2d518f84	444	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	445	return -EPERM;
dfc209c0 OH	446	if (fat_mode_can_hold_ro(inode)) {
	447	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
	448	return -EPERM;
	449	} else {
	450	if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
	451	return -EPERM;
	452	}
1278fdd3	453
2d518f84 OH	454	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	455
1278fdd3 OH	456	return 0;
	457	}
	458
e67fe633	459	static int fat_allow_set_time(struct mnt_idmap *idmap,
4b789936	460	struct msdos_sb_info sbi, struct inode inode)
1ae43f82	461	{
dacd0e7b	462	umode_t allow_utime = sbi->options.allow_utime;
1ae43f82	463
e67fe633	464	if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
41d27f51	465	current_fsuid())) {
e67fe633	466	if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
1ae43f82 OH	467	allow_utime >>= 3;
	468	if (allow_utime & MAY_WRITE)
	469	return 1;
	470	}
	471
	472	/* use a default check */
	473	return 0;
	474	}
	475
17263849	476	#define TIMES_SET_FLAGS (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)
9c0aa1b8 OH	477	/* valid file mode bits */
9c0aa1b8 OH	478	#define FAT_VALID_MODE (S_IFREG \| S_IFDIR \| S_IRWXUGO)
17263849	479
c1632a0f	480	int fat_setattr(struct mnt_idmap idmap, struct dentry dentry,
549c7297	481	struct iattr *attr)
1278fdd3 OH	482	{
1278fdd3 OH	483	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
2b0143b5	484	struct inode *inode = d_inode(dentry);
1ae43f82	485	unsigned int ia_valid;
dfc209c0	486	int error;
1278fdd3	487
1ae43f82 OH	488	/* Check for setting the inode time. */
1ae43f82 OH	489	ia_valid = attr->ia_valid;
17263849	490	if (ia_valid & TIMES_SET_FLAGS) {
e67fe633	491	if (fat_allow_set_time(idmap, sbi, inode))
17263849	492	attr->ia_valid &= ~TIMES_SET_FLAGS;
1ae43f82 OH	493	}
1ae43f82 OH	494
c1632a0f	495	error = setattr_prepare(idmap, dentry, attr);
1ae43f82	496	attr->ia_valid = ia_valid;
1278fdd3 OH	497	if (error) {
	498	if (sbi->options.quiet)
	499	error = 0;
	500	goto out;
	501	}
2d518f84	502
db78b877 CH	503	/*
	504	* Expand the file. Since inode_setattr() updates ->i_size
	505	* before calling the ->truncate(), but FAT needs to fill the
	506	* hole before it. XXX: this is no longer true with new truncate
	507	* sequence.
	508	*/
	509	if (attr->ia_valid & ATTR_SIZE) {
562c72aa CH	510	inode_dio_wait(inode);
562c72aa CH	511
db78b877 CH	512	if (attr->ia_size > inode->i_size) {
	513	error = fat_cont_expand(inode, attr->ia_size);
	514	if (error \|\| attr->ia_valid == ATTR_SIZE)
	515	goto out;
	516	attr->ia_valid &= ~ATTR_SIZE;
	517	}
	518	}
	519
1278fdd3	520	if (((attr->ia_valid & ATTR_UID) &&
4d7ca409	521	(!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
b27c82e1	522	sbi->options.fs_uid))) \|\|
1278fdd3	523	((attr->ia_valid & ATTR_GID) &&
4d7ca409	524	(!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
b27c82e1	525	sbi->options.fs_gid))) \|\|
e97e8de3	526	((attr->ia_valid & ATTR_MODE) &&
9c0aa1b8	527	(attr->ia_mode & ~FAT_VALID_MODE)))
1278fdd3 OH	528	error = -EPERM;
	529
	530	if (error) {
	531	if (sbi->options.quiet)
	532	error = 0;
	533	goto out;
	534	}
	535
2d518f84 OH	536	/*
	537	* We don't return -EPERM here. Yes, strange, but this is too
	538	* old behavior.
	539	*/
	540	if (attr->ia_valid & ATTR_MODE) {
	541	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	542	attr->ia_valid &= ~ATTR_MODE;
	543	}
1278fdd3	544
459f6ed3	545	if (attr->ia_valid & ATTR_SIZE) {
c0ef0cc9 NJ	546	error = fat_block_truncate_page(inode, attr->ia_size);
	547	if (error)
	548	goto out;
58268691	549	down_write(&MSDOS_I(inode)->truncate_lock);
2c27c65e CH	550	truncate_setsize(inode, attr->ia_size);
2c27c65e CH	551	fat_truncate_blocks(inode, attr->ia_size);
58268691	552	up_write(&MSDOS_I(inode)->truncate_lock);
459f6ed3 NP	553	}
459f6ed3 NP	554
22ea4eba FS	555	/*
	556	* setattr_copy can't truncate these appropriately, so we'll
	557	* copy them ourselves
	558	*/
	559	if (attr->ia_valid & ATTR_ATIME)
	560	fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
	561	if (attr->ia_valid & ATTR_CTIME)
	562	fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
	563	if (attr->ia_valid & ATTR_MTIME)
	564	fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
	565	attr->ia_valid &= ~(ATTR_ATIME\|ATTR_CTIME\|ATTR_MTIME);
	566
c1632a0f	567	setattr_copy(idmap, inode, attr);
459f6ed3	568	mark_inode_dirty(inode);
1278fdd3	569	out:
1278fdd3 OH	570	return error;
	571	}
	572	EXPORT_SYMBOL_GPL(fat_setattr);
	573
754661f1	574	const struct inode_operations fat_file_inode_operations = {
1278fdd3	575	.setattr = fat_setattr,
da63fc7c	576	.getattr = fat_getattr,
6bb885ec	577	.update_time = fat_update_time,
1da177e4	578	};