file.c - SHIFTPHONES/android_kernel_shift_sdm845 - Gitiles

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
  */

 #include <linux/version.h>
 #include <linux/slab.h>
 #include <linux/buffer_head.h>
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 #include <linux/cred.h>
 #endif
 #include <linux/compat.h>
 #include <linux/blkdev.h>

 #include "exfat_raw.h"
 #include "exfat_fs.h"

 static int exfat_cont_expand(struct inode *inode, loff_t size)
 {
 	struct address_space *mapping = inode->i_mapping;
 	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
 	int err, err2;

 	err = generic_cont_expand_simple(inode, size);
 	if (err)
 		return err;

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
 	inode->i_ctime = inode->i_mtime = current_time(inode);
 #else
 	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
 #endif
 	mark_inode_dirty(inode);

 	if (!IS_SYNC(inode))
 		return 0;

 	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)
 		return err;

 	return filemap_fdatawait_range(mapping, start, start + count - 1);
 }

 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
 {
 	mode_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 true;
 	}

 	/* use a default check */
 	return false;
 }

 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
 		struct inode *inode, umode_t *mode_ptr)
 {
 	mode_t i_mode, mask, perm;

 	i_mode = inode->i_mode;

 	mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
 		sbi->options.fs_fmask : sbi->options.fs_dmask;
 	perm = *mode_ptr & ~(S_IFMT | mask);

 	/* Of the r and x bits, all (subject to umask) must be present.*/
 	if ((perm & 0555) != (i_mode & 0555))
 		return -EPERM;

 	if (exfat_mode_can_hold_ro(inode)) {
 		/*
 		 * Of the w bits, either all (subject to umask) or none must
 		 * be present.
 		 */
 		if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
 			return -EPERM;
 	} else {
 		/*
 		 * If exfat_mode_can_hold_ro(inode) is false, can't change
 		 * w bits.
 		 */
 		if ((perm & 0222) != (0222 & ~mask))
 			return -EPERM;
 	}

 	*mode_ptr &= S_IFMT | perm;

 	return 0;
 }

 /* resize the file length */
 int __exfat_truncate(struct inode *inode)
 {
 	unsigned int num_clusters_new, num_clusters_phys;
 	unsigned int last_clu = EXFAT_FREE_CLUSTER;
 	struct exfat_chain clu;
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);

 	/* check if the given file ID is opened */
 	if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
 		return -EPERM;

 	exfat_set_volume_dirty(sb);

 	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
 	num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);

 	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);

 	if (i_size_read(inode) > 0) {
 		/*
 		 * Truncate FAT chain num_clusters after the first cluster
 		 * num_clusters = min(new, phys);
 		 */
 		unsigned int num_clusters =
 			min(num_clusters_new, num_clusters_phys);

 		/*
 		 * Follow FAT chain
 		 * (defensive coding - works fine even with corrupted FAT table
 		 */
 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 			clu.dir += num_clusters;
 			clu.size -= num_clusters;
 		} else {
 			while (num_clusters > 0) {
 				last_clu = clu.dir;
 				if (exfat_get_next_cluster(sb, &(clu.dir)))
 					return -EIO;

 				num_clusters--;
 				clu.size--;
 			}
 		}
 	} else {
 		ei->flags = ALLOC_NO_FAT_CHAIN;
 		ei->start_clu = EXFAT_EOF_CLUSTER;
 	}

 	if (ei->type == TYPE_FILE)
 		ei->attr |= ATTR_ARCHIVE;

 	/*
 	 * update the directory entry
 	 *
 	 * If the directory entry is updated by mark_inode_dirty(), the
 	 * directory entry will be written after a writeback cycle of
 	 * updating the bitmap/FAT, which may result in clusters being
 	 * freed but referenced by the directory entry in the event of a
 	 * sudden power failure.
 	 * __exfat_write_inode() is called for directory entry, bitmap
 	 * and FAT to be written in a same writeback.
 	 */
 	if (__exfat_write_inode(inode, inode_needs_sync(inode)))
 		return -EIO;

 	/* cut off from the FAT chain */
 	if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
 			last_clu != EXFAT_EOF_CLUSTER) {
 		if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
 			return -EIO;
 	}

 	/* invalidate cache and free the clusters */
 	/* clear exfat cache */
 	exfat_cache_inval_inode(inode);

 	/* hint information */
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;

 	/* hint_stat will be used if this is directory. */
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = ei->start_clu;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;

 	/* free the clusters */
 	if (exfat_free_cluster(inode, &clu))
 		return -EIO;

 	return 0;
 }

 void exfat_truncate(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 72)
 	unsigned int blocksize = i_blocksize(inode);
 #else
 	unsigned int blocksize = 1 << inode->i_blkbits;
 #endif
 	loff_t aligned_size;
 	int err;

 	mutex_lock(&sbi->s_lock);
 	if (ei->start_clu == 0) {
 		/*
 		 * Empty start_clu != ~0 (not allocated)
 		 */
 		exfat_fs_error(sb, "tried to truncate zeroed cluster.");
 		goto write_size;
 	}

 	err = __exfat_truncate(inode);
 	if (err)
 		goto write_size;

 	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
 write_size:
 	aligned_size = i_size_read(inode);
 	if (aligned_size & (blocksize - 1)) {
 		aligned_size |= (blocksize - 1);
 		aligned_size++;
 	}

 	if (ei->i_size_ondisk > i_size_read(inode))
 		ei->i_size_ondisk = aligned_size;

 	if (ei->i_size_aligned > i_size_read(inode))
 		ei->i_size_aligned = aligned_size;
 	mutex_unlock(&sbi->s_lock);
 }

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, unsigned int request_mask,
 		  unsigned int query_flags)
 #else
 int exfat_getattr(struct user_namespace *mnt_uerns, const struct path *path,
 		  struct kstat *stat, unsigned int request_mask,
 		  unsigned int query_flags)
 #endif
 #else
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 int exfat_getattr(const struct path *path, struct kstat *stat,
 		unsigned int request_mask, unsigned int query_flags)
 #else
 int exfat_getattr(struct vfsmount *mnt, struct dentry *dentry,
 		struct kstat *stat)
 #endif
 #endif
 {
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 	struct inode *inode = d_backing_inode(path->dentry);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 #else
 	struct inode *inode = d_inode(dentry);
 #endif

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
 	generic_fillattr(&nop_mnt_idmap, inode, stat);
 #else
 	generic_fillattr(&init_user_ns, inode, stat);
 #endif
 #else
 	generic_fillattr(inode, stat);
 #endif
 	exfat_truncate_atime(&stat->atime);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 	stat->result_mask |= STATX_BTIME;
 	stat->btime.tv_sec = ei->i_crtime.tv_sec;
 	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
 #endif
 	stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
 	return 0;
 }

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		struct iattr *attr)
 #else
 int exfat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 		struct iattr *attr)
 #endif
 #else
 int exfat_setattr(struct dentry *dentry, struct iattr *attr)
 #endif
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
 	struct inode *inode = dentry->d_inode;
 	unsigned int ia_valid;
 	int error;

 	if ((attr->ia_valid & ATTR_SIZE) &&
 	    attr->ia_size > i_size_read(inode)) {
 		error = exfat_cont_expand(inode, attr->ia_size);
 		if (error || attr->ia_valid == ATTR_SIZE)
 			return error;
 		attr->ia_valid &= ~ATTR_SIZE;
 	}

 	/* Check for setting the inode time. */
 	ia_valid = attr->ia_valid;
 	if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
 	    exfat_allow_set_time(sbi, inode)) {
 		attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
 				ATTR_TIMES_SET);
 	}

 #if ((LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0)) && \
 		(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 1, 37))) || \
 		(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0))
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
 	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
 #else
 	error = setattr_prepare(&init_user_ns, dentry, attr);
 #endif
 #else
 	error = setattr_prepare(dentry, attr);
 #endif
 #else
 	error = inode_change_ok(inode, attr);
 #endif
 	attr->ia_valid = ia_valid;
 	if (error)
 		goto out;

 	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 & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
 		error = -EPERM;
 		goto out;
 	}

 	/*
 	 * We don't return -EPERM here. Yes, strange, but this is too
 	 * old behavior.
 	 */
 	if (attr->ia_valid & ATTR_MODE) {
 		if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
 			attr->ia_valid &= ~ATTR_MODE;
 	}

 	if (attr->ia_valid & ATTR_SIZE)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
 		inode->i_mtime = inode->i_ctime = current_time(inode);
 #else
 		inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
 #endif

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
 	setattr_copy(&nop_mnt_idmap, inode, attr);
 #else
 	setattr_copy(&init_user_ns, inode, attr);
 #endif
 #else
 	setattr_copy(inode, attr);
 #endif
 	exfat_truncate_atime(&inode->i_atime);

 	if (attr->ia_valid & ATTR_SIZE) {
 		error = exfat_block_truncate_page(inode, attr->ia_size);
 		if (error)
 			goto out;

 		down_write(&EXFAT_I(inode)->truncate_lock);
 		truncate_setsize(inode, attr->ia_size);
 		/*
 		 * __exfat_write_inode() is called from exfat_truncate(), inode
 		 * is already written by it, so mark_inode_dirty() is unneeded.
 		 */
 		exfat_truncate(inode);
 		up_write(&EXFAT_I(inode)->truncate_lock);
 	} else
 		mark_inode_dirty(inode);
 out:
 	return error;
 }

 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
 {
 #if LINUX_VERSION_CODE < KERNEL_VERSION(5, 19, 0)
 	struct request_queue *q = bdev_get_queue(inode->i_sb->s_bdev);
 #endif
 	struct fstrim_range range;
 	int ret = 0;

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

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
 	if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
 #else
 	if (!blk_queue_discard(q))
 #endif
 		return -EOPNOTSUPP;

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

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
 	range.minlen = max_t(unsigned int, range.minlen,
 				bdev_discard_granularity(inode->i_sb->s_bdev));
 #else
 	range.minlen = max_t(unsigned int, range.minlen,
 				q->limits.discard_granularity);
 #endif

 	ret = exfat_trim_fs(inode, &range);
 	if (ret < 0)
 		return ret;

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

 	return 0;
 }

 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = file_inode(filp);

 	switch (cmd) {
 	case FITRIM:
 		return exfat_ioctl_fitrim(inode, arg);
 	default:
 		return -ENOTTY;
 	}
 }

 #ifdef CONFIG_COMPAT
 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
 				unsigned long arg)
 {
 	return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
 }
 #endif

 int exfat_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_blockdev(inode->i_sb->s_bdev);
 	if (err)
 		return err;

 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
 	return blkdev_issue_flush(inode->i_sb->s_bdev);
 #else
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
 	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
 #else
 	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
 #endif
 #endif
 }

 const struct file_operations exfat_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read_iter	= generic_file_read_iter,
 	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl = exfat_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = exfat_compat_ioctl,
 #endif
 	.mmap		= generic_file_mmap,
 	.fsync		= exfat_file_fsync,
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0)
 	.splice_read	= filemap_splice_read,
 #else
 	.splice_read	= generic_file_splice_read,
 #endif
 	.splice_write	= iter_file_splice_write,
 };

 const struct inode_operations exfat_file_inode_operations = {
 	.setattr     = exfat_setattr,
 	.getattr     = exfat_getattr,
 };
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
	*/

	#include <linux/version.h>
	#include <linux/slab.h>
	#include <linux/buffer_head.h>
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
	#include <linux/cred.h>
	#endif
	#include <linux/compat.h>
	#include <linux/blkdev.h>

	#include "exfat_raw.h"
	#include "exfat_fs.h"

	static int exfat_cont_expand(struct inode *inode, loff_t size)
	{
	struct address_space *mapping = inode->i_mapping;
	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
	int err, err2;

	err = generic_cont_expand_simple(inode, size);
	if (err)
	return err;

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
	inode->i_ctime = inode->i_mtime = current_time(inode);
	#else
	inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
	#endif
	mark_inode_dirty(inode);

	if (!IS_SYNC(inode))
	return 0;

	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)
	return err;

	return filemap_fdatawait_range(mapping, start, start + count - 1);
	}

	static bool exfat_allow_set_time(struct exfat_sb_info sbi, struct inode inode)
	{
	mode_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 true;
	}

	/* use a default check */
	return false;
	}

	static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
	struct inode inode, umode_t mode_ptr)
	{
	mode_t i_mode, mask, perm;

	i_mode = inode->i_mode;

	mask = (S_ISREG(i_mode) \|\| S_ISLNK(i_mode)) ?
	sbi->options.fs_fmask : sbi->options.fs_dmask;
	perm = *mode_ptr & ~(S_IFMT \| mask);

	/* Of the r and x bits, all (subject to umask) must be present.*/
	if ((perm & 0555) != (i_mode & 0555))
	return -EPERM;

	if (exfat_mode_can_hold_ro(inode)) {
	/*
	* Of the w bits, either all (subject to umask) or none must
	* be present.
	*/
	if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
	return -EPERM;
	} else {
	/*
	* If exfat_mode_can_hold_ro(inode) is false, can't change
	* w bits.
	*/
	if ((perm & 0222) != (0222 & ~mask))
	return -EPERM;
	}

	*mode_ptr &= S_IFMT \| perm;

	return 0;
	}

	/* resize the file length */
	int __exfat_truncate(struct inode *inode)
	{
	unsigned int num_clusters_new, num_clusters_phys;
	unsigned int last_clu = EXFAT_FREE_CLUSTER;
	struct exfat_chain clu;
	struct super_block *sb = inode->i_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct exfat_inode_info *ei = EXFAT_I(inode);

	/* check if the given file ID is opened */
	if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
	return -EPERM;

	exfat_set_volume_dirty(sb);

	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
	num_clusters_phys = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);

	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);

	if (i_size_read(inode) > 0) {
	/*
	* Truncate FAT chain num_clusters after the first cluster
	* num_clusters = min(new, phys);
	*/
	unsigned int num_clusters =
	min(num_clusters_new, num_clusters_phys);

	/*
	* Follow FAT chain
	* (defensive coding - works fine even with corrupted FAT table
	*/
	if (clu.flags == ALLOC_NO_FAT_CHAIN) {
	clu.dir += num_clusters;
	clu.size -= num_clusters;
	} else {
	while (num_clusters > 0) {
	last_clu = clu.dir;
	if (exfat_get_next_cluster(sb, &(clu.dir)))
	return -EIO;

	num_clusters--;
	clu.size--;
	}
	}
	} else {
	ei->flags = ALLOC_NO_FAT_CHAIN;
	ei->start_clu = EXFAT_EOF_CLUSTER;
	}

	if (ei->type == TYPE_FILE)
	ei->attr \|= ATTR_ARCHIVE;

	/*
	* update the directory entry
	*
	* If the directory entry is updated by mark_inode_dirty(), the
	* directory entry will be written after a writeback cycle of
	* updating the bitmap/FAT, which may result in clusters being
	* freed but referenced by the directory entry in the event of a
	* sudden power failure.
	* __exfat_write_inode() is called for directory entry, bitmap
	* and FAT to be written in a same writeback.
	*/
	if (__exfat_write_inode(inode, inode_needs_sync(inode)))
	return -EIO;

	/* cut off from the FAT chain */
	if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
	last_clu != EXFAT_EOF_CLUSTER) {
	if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
	return -EIO;
	}

	/* invalidate cache and free the clusters */
	/* clear exfat cache */
	exfat_cache_inval_inode(inode);

	/* hint information */
	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;

	/* hint_stat will be used if this is directory. */
	ei->hint_stat.eidx = 0;
	ei->hint_stat.clu = ei->start_clu;
	ei->hint_femp.eidx = EXFAT_HINT_NONE;

	/* free the clusters */
	if (exfat_free_cluster(inode, &clu))
	return -EIO;

	return 0;
	}

	void exfat_truncate(struct inode *inode)
	{
	struct super_block *sb = inode->i_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct exfat_inode_info *ei = EXFAT_I(inode);
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 72)
	unsigned int blocksize = i_blocksize(inode);
	#else
	unsigned int blocksize = 1 << inode->i_blkbits;
	#endif
	loff_t aligned_size;
	int err;

	mutex_lock(&sbi->s_lock);
	if (ei->start_clu == 0) {
	/*
	* Empty start_clu != ~0 (not allocated)
	*/
	exfat_fs_error(sb, "tried to truncate zeroed cluster.");
	goto write_size;
	}

	err = __exfat_truncate(inode);
	if (err)
	goto write_size;

	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
	write_size:
	aligned_size = i_size_read(inode);
	if (aligned_size & (blocksize - 1)) {
	aligned_size \|= (blocksize - 1);
	aligned_size++;
	}

	if (ei->i_size_ondisk > i_size_read(inode))
	ei->i_size_ondisk = aligned_size;

	if (ei->i_size_aligned > i_size_read(inode))
	ei->i_size_aligned = aligned_size;
	mutex_unlock(&sbi->s_lock);
	}

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
	int exfat_getattr(struct mnt_idmap idmap, const struct path path,
	struct kstat *stat, unsigned int request_mask,
	unsigned int query_flags)
	#else
	int exfat_getattr(struct user_namespace mnt_uerns, const struct path path,
	struct kstat *stat, unsigned int request_mask,
	unsigned int query_flags)
	#endif
	#else
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
	int exfat_getattr(const struct path path, struct kstat stat,
	unsigned int request_mask, unsigned int query_flags)
	#else
	int exfat_getattr(struct vfsmount mnt, struct dentry dentry,
	struct kstat *stat)
	#endif
	#endif
	{
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
	struct inode *inode = d_backing_inode(path->dentry);
	struct exfat_inode_info *ei = EXFAT_I(inode);
	#else
	struct inode *inode = d_inode(dentry);
	#endif

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
	generic_fillattr(&nop_mnt_idmap, inode, stat);
	#else
	generic_fillattr(&init_user_ns, inode, stat);
	#endif
	#else
	generic_fillattr(inode, stat);
	#endif
	exfat_truncate_atime(&stat->atime);
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
	stat->result_mask \|= STATX_BTIME;
	stat->btime.tv_sec = ei->i_crtime.tv_sec;
	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
	#endif
	stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
	return 0;
	}

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
	int exfat_setattr(struct mnt_idmap idmap, struct dentry dentry,
	struct iattr *attr)
	#else
	int exfat_setattr(struct user_namespace mnt_userns, struct dentry dentry,
	struct iattr *attr)
	#endif
	#else
	int exfat_setattr(struct dentry dentry, struct iattr attr)
	#endif
	{
	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
	struct inode *inode = dentry->d_inode;
	unsigned int ia_valid;
	int error;

	if ((attr->ia_valid & ATTR_SIZE) &&
	attr->ia_size > i_size_read(inode)) {
	error = exfat_cont_expand(inode, attr->ia_size);
	if (error \|\| attr->ia_valid == ATTR_SIZE)
	return error;
	attr->ia_valid &= ~ATTR_SIZE;
	}

	/* Check for setting the inode time. */
	ia_valid = attr->ia_valid;
	if ((ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)) &&
	exfat_allow_set_time(sbi, inode)) {
	attr->ia_valid &= ~(ATTR_MTIME_SET \| ATTR_ATIME_SET \|
	ATTR_TIMES_SET);
	}

	#if ((LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0)) && \
	(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 1, 37))) \|\| \
	(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0))
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
	#else
	error = setattr_prepare(&init_user_ns, dentry, attr);
	#endif
	#else
	error = setattr_prepare(dentry, attr);
	#endif
	#else
	error = inode_change_ok(inode, attr);
	#endif
	attr->ia_valid = ia_valid;
	if (error)
	goto out;

	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 & ~(S_IFREG \| S_IFLNK \| S_IFDIR \| 0777)))) {
	error = -EPERM;
	goto out;
	}

	/*
	* We don't return -EPERM here. Yes, strange, but this is too
	* old behavior.
	*/
	if (attr->ia_valid & ATTR_MODE) {
	if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	attr->ia_valid &= ~ATTR_MODE;
	}

	if (attr->ia_valid & ATTR_SIZE)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
	inode->i_mtime = inode->i_ctime = current_time(inode);
	#else
	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
	#endif

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
	setattr_copy(&nop_mnt_idmap, inode, attr);
	#else
	setattr_copy(&init_user_ns, inode, attr);
	#endif
	#else
	setattr_copy(inode, attr);
	#endif
	exfat_truncate_atime(&inode->i_atime);

	if (attr->ia_valid & ATTR_SIZE) {
	error = exfat_block_truncate_page(inode, attr->ia_size);
	if (error)
	goto out;

	down_write(&EXFAT_I(inode)->truncate_lock);
	truncate_setsize(inode, attr->ia_size);
	/*
	* __exfat_write_inode() is called from exfat_truncate(), inode
	* is already written by it, so mark_inode_dirty() is unneeded.
	*/
	exfat_truncate(inode);
	up_write(&EXFAT_I(inode)->truncate_lock);
	} else
	mark_inode_dirty(inode);
	out:
	return error;
	}

	static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
	{
	#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 19, 0)
	struct request_queue *q = bdev_get_queue(inode->i_sb->s_bdev);
	#endif
	struct fstrim_range range;
	int ret = 0;

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

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
	if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
	#else
	if (!blk_queue_discard(q))
	#endif
	return -EOPNOTSUPP;

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

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 19, 0)
	range.minlen = max_t(unsigned int, range.minlen,
	bdev_discard_granularity(inode->i_sb->s_bdev));
	#else
	range.minlen = max_t(unsigned int, range.minlen,
	q->limits.discard_granularity);
	#endif

	ret = exfat_trim_fs(inode, &range);
	if (ret < 0)
	return ret;

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

	return 0;
	}

	long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	struct inode *inode = file_inode(filp);

	switch (cmd) {
	case FITRIM:
	return exfat_ioctl_fitrim(inode, arg);
	default:
	return -ENOTTY;
	}
	}

	#ifdef CONFIG_COMPAT
	long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
	unsigned long arg)
	{
	return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
	}
	#endif

	int exfat_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_blockdev(inode->i_sb->s_bdev);
	if (err)
	return err;

	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
	return blkdev_issue_flush(inode->i_sb->s_bdev);
	#else
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
	#else
	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
	#endif
	#endif
	}

	const struct file_operations exfat_file_operations = {
	.llseek = generic_file_llseek,
	.read_iter = generic_file_read_iter,
	.write_iter = generic_file_write_iter,
	.unlocked_ioctl = exfat_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = exfat_compat_ioctl,
	#endif
	.mmap = generic_file_mmap,
	.fsync = exfat_file_fsync,
	#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0)
	.splice_read = filemap_splice_read,
	#else
	.splice_read = generic_file_splice_read,
	#endif
	.splice_write = iter_file_splice_write,
	};

	const struct inode_operations exfat_file_inode_operations = {
	.setattr = exfat_setattr,
	.getattr = exfat_getattr,
	};