[mirror_ubuntu-jammy-kernel.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->f_path.dentry, &ia);
	if (err)
		goto out_unlock_inode;

	/* This MUST be done before doing anything irreversible... */
	err = fat_setattr(file_mnt_user_ns(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;
	struct request_queue *q = bdev_get_queue(sb->s_bdev);
	int err;

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

	if (!blk_queue_discard(q))
		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,
			     q->limits.discard_granularity);

	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);
		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 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	= generic_file_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 user_namespace *mnt_userns, const struct path *path,
		struct kstat *stat, u32 request_mask, unsigned int flags)
{
	struct inode *inode = d_inode(path->dentry);
	generic_fillattr(mnt_userns, 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 user_namespace *mnt_userns,
			      struct msdos_sb_info *sbi, struct inode *inode)
{
	umode_t allow_utime = sbi->options.allow_utime;

	if (!uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode))) {
		if (in_group_p(i_gid_into_mnt(mnt_userns, 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 user_namespace *mnt_userns, 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(mnt_userns, sbi, inode))
			attr->ia_valid &= ~TIMES_SET_FLAGS;
	}

	error = setattr_prepare(mnt_userns, 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(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 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(mnt_userns, 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	*/
	93	err = security_inode_setattr(file->f_path.dentry, &ia);
	94	if (err)
e24f17da	95	goto out_unlock_inode;
1da177e4	96
21bea495	97	/* This MUST be done before doing anything irreversible... */
549c7297	98	err = fat_setattr(file_mnt_user_ns(file), file->f_path.dentry, &ia);
21bea495	99	if (err)
e24f17da	100	goto out_unlock_inode;
21bea495 CH	101
	102	fsnotify_change(file->f_path.dentry, ia.ia_valid);
	103	if (sbi->options.sys_immutable) {
	104	if (attr & ATTR_SYS)
	105	inode->i_flags \|= S_IMMUTABLE;
	106	else
1adffbae	107	inode->i_flags &= ~S_IMMUTABLE;
21bea495	108	}
1da177e4	109
21bea495 CH	110	fat_save_attrs(inode, attr);
21bea495 CH	111	mark_inode_dirty(inode);
21bea495	112	out_unlock_inode:
5955102c	113	inode_unlock(inode);
e24f17da	114	mnt_drop_write_file(file);
21bea495 CH	115	out:
	116	return err;
	117	}
1da177e4	118
6e5b93ee ML	119	static int fat_ioctl_get_volume_id(struct inode inode, u32 __user user_attr)
	120	{
	121	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
	122	return put_user(sbi->vol_id, user_attr);
	123	}
	124
f663b5b3 WW	125	static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
	126	{
	127	struct super_block *sb = inode->i_sb;
	128	struct fstrim_range __user *user_range;
	129	struct fstrim_range range;
	130	struct request_queue *q = bdev_get_queue(sb->s_bdev);
	131	int err;
	132
	133	if (!capable(CAP_SYS_ADMIN))
	134	return -EPERM;
	135
	136	if (!blk_queue_discard(q))
	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,
	144	q->limits.discard_granularity);
	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) &&
	178	MSDOS_SB(inode->i_sb)->options.flush) {
	179	fat_flush_inodes(inode->i_sb, inode, NULL);
8aa7e847	180	congestion_wait(BLK_RW_ASYNC, HZ/10);
ae78bf9c CM	181	}
	182	return 0;
	183	}
	184
02c24a82	185	int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
b522412a	186	{
7ea80859	187	struct inode *inode = filp->f_mapping->host;
bd8309de HT	188	int err;
	189
	190	err = __generic_file_fsync(filp, start, end, datasync);
	191	if (err)
	192	return err;
b522412a	193
b522412a	194	err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
bd8309de HT	195	if (err)
bd8309de HT	196	return err;
b522412a	197
c6bf3f0e	198	return blkdev_issue_flush(inode->i_sb->s_bdev);
b522412a AV	199	}
	200
	201
4b6f5d20	202	const struct file_operations fat_file_operations = {
1da177e4	203	.llseek = generic_file_llseek,
aad4f8bb	204	.read_iter = generic_file_read_iter,
8174202b	205	.write_iter = generic_file_write_iter,
1da177e4	206	.mmap = generic_file_mmap,
ae78bf9c	207	.release = fat_file_release,
7845bc3e	208	.unlocked_ioctl = fat_generic_ioctl,
407e9ef7	209	.compat_ioctl = compat_ptr_ioctl,
b522412a	210	.fsync = fat_file_fsync,
5ffc4ef4	211	.splice_read = generic_file_splice_read,
67ceb1ec	212	.splice_write = iter_file_splice_write,
b13bb33e	213	.fallocate = fat_fallocate,
1da177e4 LT	214	};
1da177e4 LT	215
05eb0b51 OH	216	static int fat_cont_expand(struct inode *inode, loff_t size)
	217	{
	218	struct address_space *mapping = inode->i_mapping;
	219	loff_t start = inode->i_size, count = size - inode->i_size;
	220	int err;
	221
	222	err = generic_cont_expand_simple(inode, size);
	223	if (err)
	224	goto out;
	225
cd83f6b1	226	fat_truncate_time(inode, NULL, S_CTIME\|S_MTIME);
05eb0b51	227	mark_inode_dirty(inode);
2f3d675b JK	228	if (IS_SYNC(inode)) {
	229	int err2;
	230
	231	/*
	232	* Opencode syncing since we don't have a file open to use
	233	* standard fsync path.
	234	*/
	235	err = filemap_fdatawrite_range(mapping, start,
	236	start + count - 1);
	237	err2 = sync_mapping_buffers(mapping);
	238	if (!err)
	239	err = err2;
	240	err2 = write_inode_now(inode, 1);
	241	if (!err)
	242	err = err2;
	243	if (!err) {
	244	err = filemap_fdatawait_range(mapping, start,
	245	start + count - 1);
	246	}
	247	}
05eb0b51 OH	248	out:
	249	return err;
	250	}
	251
b13bb33e NJ	252	/*
	253	* Preallocate space for a file. This implements fat's fallocate file
	254	* operation, which gets called from sys_fallocate system call. User
	255	* space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
	256	* we just allocate clusters without zeroing them out. Otherwise we
	257	* allocate and zero out clusters via an expanding truncate.
	258	*/
	259	static long fat_fallocate(struct file *file, int mode,
	260	loff_t offset, loff_t len)
	261	{
	262	int nr_cluster; /* Number of clusters to be allocated */
	263	loff_t mm_bytes; /* Number of bytes to be allocated for file */
	264	loff_t ondisksize; /* block aligned on-disk size in bytes*/
	265	struct inode *inode = file->f_mapping->host;
	266	struct super_block *sb = inode->i_sb;
	267	struct msdos_sb_info *sbi = MSDOS_SB(sb);
	268	int err = 0;
	269
	270	/* No support for hole punch or other fallocate flags. */
	271	if (mode & ~FALLOC_FL_KEEP_SIZE)
	272	return -EOPNOTSUPP;
	273
	274	/* No support for dir */
	275	if (!S_ISREG(inode->i_mode))
	276	return -EOPNOTSUPP;
	277
5955102c	278	inode_lock(inode);
b13bb33e NJ	279	if (mode & FALLOC_FL_KEEP_SIZE) {
	280	ondisksize = inode->i_blocks << 9;
	281	if ((offset + len) <= ondisksize)
	282	goto error;
	283
	284	/* First compute the number of clusters to be allocated */
	285	mm_bytes = offset + len - ondisksize;
	286	nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
	287	sbi->cluster_bits;
	288
	289	/* Start the allocation.We are not zeroing out the clusters */
	290	while (nr_cluster-- > 0) {
	291	err = fat_add_cluster(inode);
	292	if (err)
	293	goto error;
	294	}
	295	} else {
	296	if ((offset + len) <= i_size_read(inode))
	297	goto error;
	298
	299	/* This is just an expanding truncate */
	300	err = fat_cont_expand(inode, (offset + len));
	301	}
	302
	303	error:
5955102c	304	inode_unlock(inode);
b13bb33e NJ	305	return err;
	306	}
	307
1da177e4 LT	308	/* Free all clusters after the skip'th cluster. */
	309	static int fat_free(struct inode *inode, int skip)
	310	{
	311	struct super_block *sb = inode->i_sb;
	312	int err, wait, free_start, i_start, i_logstart;
	313
	314	if (MSDOS_I(inode)->i_start == 0)
	315	return 0;
	316
3b641407 OH	317	fat_cache_inval_inode(inode);
3b641407 OH	318
1da177e4	319	wait = IS_DIRSYNC(inode);
3b641407 OH	320	i_start = free_start = MSDOS_I(inode)->i_start;
	321	i_logstart = MSDOS_I(inode)->i_logstart;
	322
	323	/* First, we write the new file size. */
	324	if (!skip) {
	325	MSDOS_I(inode)->i_start = 0;
	326	MSDOS_I(inode)->i_logstart = 0;
	327	}
	328	MSDOS_I(inode)->i_attrs \|= ATTR_ARCH;
cd83f6b1	329	fat_truncate_time(inode, NULL, S_CTIME\|S_MTIME);
3b641407 OH	330	if (wait) {
	331	err = fat_sync_inode(inode);
	332	if (err) {
	333	MSDOS_I(inode)->i_start = i_start;
	334	MSDOS_I(inode)->i_logstart = i_logstart;
	335	return err;
	336	}
	337	} else
	338	mark_inode_dirty(inode);
	339
	340	/* Write a new EOF, and get the remaining cluster chain for freeing. */
1da177e4 LT	341	if (skip) {
	342	struct fat_entry fatent;
	343	int ret, fclus, dclus;
	344
	345	ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
	346	if (ret < 0)
	347	return ret;
	348	else if (ret == FAT_ENT_EOF)
	349	return 0;
	350
	351	fatent_init(&fatent);
	352	ret = fat_ent_read(inode, &fatent, dclus);
	353	if (ret == FAT_ENT_EOF) {
	354	fatent_brelse(&fatent);
	355	return 0;
	356	} else if (ret == FAT_ENT_FREE) {
85c78591	357	fat_fs_error(sb,
1da177e4	358	"%s: invalid cluster chain (i_pos %lld)",
8e24eea7	359	__func__, MSDOS_I(inode)->i_pos);
1da177e4 LT	360	ret = -EIO;
	361	} else if (ret > 0) {
	362	err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
	363	if (err)
	364	ret = err;
	365	}
	366	fatent_brelse(&fatent);
	367	if (ret < 0)
	368	return ret;
	369
	370	free_start = ret;
1da177e4	371	}
1da177e4 LT	372	inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
	373
	374	/* Freeing the remained cluster chain */
	375	return fat_free_clusters(inode, free_start);
1da177e4 LT	376	}
1da177e4 LT	377
459f6ed3	378	void fat_truncate_blocks(struct inode *inode, loff_t offset)
1da177e4	379	{
9c20616c	380	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1da177e4 LT	381	const unsigned int cluster_size = sbi->cluster_size;
	382	int nr_clusters;
	383
	384	/*
	385	* This protects against truncating a file bigger than it was then
	386	* trying to write into the hole.
	387	*/
459f6ed3 NP	388	if (MSDOS_I(inode)->mmu_private > offset)
459f6ed3 NP	389	MSDOS_I(inode)->mmu_private = offset;
1da177e4	390
459f6ed3	391	nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
1da177e4	392
1da177e4	393	fat_free(inode, nr_clusters);
ae78bf9c	394	fat_flush_inodes(inode->i_sb, inode, NULL);
1da177e4 LT	395	}
1da177e4 LT	396
549c7297 CB	397	int fat_getattr(struct user_namespace mnt_userns, const struct path path,
549c7297 CB	398	struct kstat *stat, u32 request_mask, unsigned int flags)
da63fc7c	399	{
a528d35e	400	struct inode *inode = d_inode(path->dentry);
4b789936	401	generic_fillattr(mnt_userns, inode, stat);
da63fc7c	402	stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
ea3983ac NJ	403
	404	if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
	405	/* Use i_pos for ino. This is used as fileid of nfs. */
	406	stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
	407	}
da63fc7c OH	408	return 0;
	409	}
	410	EXPORT_SYMBOL_GPL(fat_getattr);
	411
2d518f84 OH	412	static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
2d518f84 OH	413	struct inode inode, umode_t mode_ptr)
1278fdd3	414	{
dacd0e7b	415	umode_t mask, perm;
1278fdd3	416
2d518f84 OH	417	/*
2d518f84 OH	418	* Note, the basic check is already done by a caller of
9c0aa1b8	419	* (attr->ia_mode & ~FAT_VALID_MODE)
2d518f84 OH	420	*/
	421
	422	if (S_ISREG(inode->i_mode))
1278fdd3 OH	423	mask = sbi->options.fs_fmask;
	424	else
	425	mask = sbi->options.fs_dmask;
	426
2d518f84 OH	427	perm = *mode_ptr & ~(S_IFMT \| mask);
2d518f84 OH	428
1278fdd3 OH	429	/*
	430	* Of the r and x bits, all (subject to umask) must be present. Of the
	431	* w bits, either all (subject to umask) or none must be present.
dfc209c0 OH	432	*
dfc209c0 OH	433	* If fat_mode_can_hold_ro(inode) is false, can't change w bits.
1278fdd3	434	*/
2d518f84	435	if ((perm & (S_IRUGO \| S_IXUGO)) != (inode->i_mode & (S_IRUGO\|S_IXUGO)))
1278fdd3	436	return -EPERM;
dfc209c0 OH	437	if (fat_mode_can_hold_ro(inode)) {
	438	if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
	439	return -EPERM;
	440	} else {
	441	if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
	442	return -EPERM;
	443	}
1278fdd3	444
2d518f84 OH	445	*mode_ptr &= S_IFMT \| perm;
2d518f84 OH	446
1278fdd3 OH	447	return 0;
	448	}
	449
4b789936 CB	450	static int fat_allow_set_time(struct user_namespace *mnt_userns,
4b789936 CB	451	struct msdos_sb_info sbi, struct inode inode)
1ae43f82	452	{
dacd0e7b	453	umode_t allow_utime = sbi->options.allow_utime;
1ae43f82	454
4b789936 CB	455	if (!uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode))) {
4b789936 CB	456	if (in_group_p(i_gid_into_mnt(mnt_userns, inode)))
1ae43f82 OH	457	allow_utime >>= 3;
	458	if (allow_utime & MAY_WRITE)
	459	return 1;
	460	}
	461
	462	/* use a default check */
	463	return 0;
	464	}
	465
17263849	466	#define TIMES_SET_FLAGS (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)
9c0aa1b8 OH	467	/* valid file mode bits */
9c0aa1b8 OH	468	#define FAT_VALID_MODE (S_IFREG \| S_IFDIR \| S_IRWXUGO)
17263849	469
549c7297 CB	470	int fat_setattr(struct user_namespace mnt_userns, struct dentry dentry,
549c7297 CB	471	struct iattr *attr)
1278fdd3 OH	472	{
1278fdd3 OH	473	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
2b0143b5	474	struct inode *inode = d_inode(dentry);
1ae43f82	475	unsigned int ia_valid;
dfc209c0	476	int error;
1278fdd3	477
1ae43f82 OH	478	/* Check for setting the inode time. */
1ae43f82 OH	479	ia_valid = attr->ia_valid;
17263849	480	if (ia_valid & TIMES_SET_FLAGS) {
4b789936	481	if (fat_allow_set_time(mnt_userns, sbi, inode))
17263849	482	attr->ia_valid &= ~TIMES_SET_FLAGS;
1ae43f82 OH	483	}
1ae43f82 OH	484
4b789936	485	error = setattr_prepare(mnt_userns, dentry, attr);
1ae43f82	486	attr->ia_valid = ia_valid;
1278fdd3 OH	487	if (error) {
	488	if (sbi->options.quiet)
	489	error = 0;
	490	goto out;
	491	}
2d518f84	492
db78b877 CH	493	/*
	494	* Expand the file. Since inode_setattr() updates ->i_size
	495	* before calling the ->truncate(), but FAT needs to fill the
	496	* hole before it. XXX: this is no longer true with new truncate
	497	* sequence.
	498	*/
	499	if (attr->ia_valid & ATTR_SIZE) {
562c72aa CH	500	inode_dio_wait(inode);
562c72aa CH	501
db78b877 CH	502	if (attr->ia_size > inode->i_size) {
	503	error = fat_cont_expand(inode, attr->ia_size);
	504	if (error \|\| attr->ia_valid == ATTR_SIZE)
	505	goto out;
	506	attr->ia_valid &= ~ATTR_SIZE;
	507	}
	508	}
	509
1278fdd3	510	if (((attr->ia_valid & ATTR_UID) &&
170782eb	511	(!uid_eq(attr->ia_uid, sbi->options.fs_uid))) \|\|
1278fdd3	512	((attr->ia_valid & ATTR_GID) &&
170782eb	513	(!gid_eq(attr->ia_gid, sbi->options.fs_gid))) \|\|
e97e8de3	514	((attr->ia_valid & ATTR_MODE) &&
9c0aa1b8	515	(attr->ia_mode & ~FAT_VALID_MODE)))
1278fdd3 OH	516	error = -EPERM;
	517
	518	if (error) {
	519	if (sbi->options.quiet)
	520	error = 0;
	521	goto out;
	522	}
	523
2d518f84 OH	524	/*
	525	* We don't return -EPERM here. Yes, strange, but this is too
	526	* old behavior.
	527	*/
	528	if (attr->ia_valid & ATTR_MODE) {
	529	if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	530	attr->ia_valid &= ~ATTR_MODE;
	531	}
1278fdd3	532
459f6ed3	533	if (attr->ia_valid & ATTR_SIZE) {
c0ef0cc9 NJ	534	error = fat_block_truncate_page(inode, attr->ia_size);
	535	if (error)
	536	goto out;
58268691	537	down_write(&MSDOS_I(inode)->truncate_lock);
2c27c65e CH	538	truncate_setsize(inode, attr->ia_size);
2c27c65e CH	539	fat_truncate_blocks(inode, attr->ia_size);
58268691	540	up_write(&MSDOS_I(inode)->truncate_lock);
459f6ed3 NP	541	}
459f6ed3 NP	542
22ea4eba FS	543	/*
	544	* setattr_copy can't truncate these appropriately, so we'll
	545	* copy them ourselves
	546	*/
	547	if (attr->ia_valid & ATTR_ATIME)
	548	fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
	549	if (attr->ia_valid & ATTR_CTIME)
	550	fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
	551	if (attr->ia_valid & ATTR_MTIME)
	552	fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
	553	attr->ia_valid &= ~(ATTR_ATIME\|ATTR_CTIME\|ATTR_MTIME);
	554
4b789936	555	setattr_copy(mnt_userns, inode, attr);
459f6ed3	556	mark_inode_dirty(inode);
1278fdd3	557	out:
1278fdd3 OH	558	return error;
	559	}
	560	EXPORT_SYMBOL_GPL(fat_setattr);
	561
754661f1	562	const struct inode_operations fat_file_inode_operations = {
1278fdd3	563	.setattr = fat_setattr,
da63fc7c	564	.getattr = fat_getattr,
6bb885ec	565	.update_time = fat_update_time,
1da177e4	566	};