fs/ntfs3: Add file operations and implementation

This adds file operations and implementation

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

1 files changed, 1252 insertions, 0 deletions

diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
new file mode 100644
index 000000000000..59344985c2e8
--- /dev/null
+++ b/fs/ntfs3/file.c
@@ -0,0 +1,1252 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ *  regular file handling primitives for ntfs-based filesystems
+ */
+#include <linux/backing-dev.h>
+#include <linux/buffer_head.h>
+#include <linux/compat.h>
+#include <linux/falloc.h>
+#include <linux/fiemap.h>
+#include <linux/msdos_fs.h> /* FAT_IOCTL_XXX */
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+static int ntfs_ioctl_fitrim(struct ntfs_sb_info *sbi, unsigned long arg)
+{
+	struct fstrim_range __user *user_range;
+	struct fstrim_range range;
+	struct request_queue *q = bdev_get_queue(sbi->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(u32, range.minlen, q->limits.discard_granularity);
+
+	err = ntfs_trim_fs(sbi, &range);
+	if (err < 0)
+		return err;
+
+	if (copy_to_user(user_range, &range, sizeof(range)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ntfs_ioctl(struct file *filp, u32 cmd, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
+	u32 __user *user_attr = (u32 __user *)arg;
+
+	switch (cmd) {
+	case FAT_IOCTL_GET_ATTRIBUTES:
+		return put_user(le32_to_cpu(ntfs_i(inode)->std_fa), user_attr);
+
+	case FAT_IOCTL_GET_VOLUME_ID:
+		return put_user(sbi->volume.ser_num, user_attr);
+
+	case FITRIM:
+		return ntfs_ioctl_fitrim(sbi, arg);
+	}
+	return -ENOTTY; /* Inappropriate ioctl for device */
+}
+
+#ifdef CONFIG_COMPAT
+static long ntfs_compat_ioctl(struct file *filp, u32 cmd, unsigned long arg)
+
+{
+	return ntfs_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif
+
+/*
+ * inode_operations::getattr
+ */
+int ntfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
+		 struct kstat *stat, u32 request_mask, u32 flags)
+{
+	struct inode *inode = d_inode(path->dentry);
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (is_compressed(ni))
+		stat->attributes |= STATX_ATTR_COMPRESSED;
+
+	if (is_encrypted(ni))
+		stat->attributes |= STATX_ATTR_ENCRYPTED;
+
+	stat->attributes_mask |= STATX_ATTR_COMPRESSED | STATX_ATTR_ENCRYPTED;
+
+	generic_fillattr(mnt_userns, inode, stat);
+
+	stat->result_mask |= STATX_BTIME;
+	stat->btime = ni->i_crtime;
+	stat->blksize = ni->mi.sbi->cluster_size; /* 512, 1K, ..., 2M */
+
+	return 0;
+}
+
+static int ntfs_extend_initialized_size(struct file *file,
+					struct ntfs_inode *ni,
+					const loff_t valid,
+					const loff_t new_valid)
+{
+	struct inode *inode = &ni->vfs_inode;
+	struct address_space *mapping = inode->i_mapping;
+	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
+	loff_t pos = valid;
+	int err;
+
+	if (is_resident(ni)) {
+		ni->i_valid = new_valid;
+		return 0;
+	}
+
+	WARN_ON(is_compressed(ni));
+	WARN_ON(valid >= new_valid);
+
+	for (;;) {
+		u32 zerofrom, len;
+		struct page *page;
+		void *fsdata;
+		u8 bits;
+		CLST vcn, lcn, clen;
+
+		if (is_sparsed(ni)) {
+			bits = sbi->cluster_bits;
+			vcn = pos >> bits;
+
+			err = attr_data_get_block(ni, vcn, 0, &lcn, &clen,
+						  NULL);
+			if (err)
+				goto out;
+
+			if (lcn == SPARSE_LCN) {
+				loff_t vbo = (loff_t)vcn << bits;
+				loff_t to = vbo + ((loff_t)clen << bits);
+
+				if (to <= new_valid) {
+					ni->i_valid = to;
+					pos = to;
+					goto next;
+				}
+
+				if (vbo < pos) {
+					pos = vbo;
+				} else {
+					to = (new_valid >> bits) << bits;
+					if (pos < to) {
+						ni->i_valid = to;
+						pos = to;
+						goto next;
+					}
+				}
+			}
+		}
+
+		zerofrom = pos & (PAGE_SIZE - 1);
+		len = PAGE_SIZE - zerofrom;
+
+		if (pos + len > new_valid)
+			len = new_valid - pos;
+
+		err = pagecache_write_begin(file, mapping, pos, len, 0, &page,
+					    &fsdata);
+		if (err)
+			goto out;
+
+		zero_user_segment(page, zerofrom, PAGE_SIZE);
+
+		/* this function in any case puts page*/
+		err = pagecache_write_end(file, mapping, pos, len, len, page,
+					  fsdata);
+		if (err < 0)
+			goto out;
+		pos += len;
+
+next:
+		if (pos >= new_valid)
+			break;
+
+		balance_dirty_pages_ratelimited(mapping);
+		cond_resched();
+	}
+
+	return 0;
+
+out:
+	ni->i_valid = valid;
+	ntfs_inode_warn(inode, "failed to extend initialized size to %llx.",
+			new_valid);
+	return err;
+}
+
+/*
+ * ntfs_zero_range
+ *
+ * Helper function for punch_hole.
+ * It zeroes a range [vbo, vbo_to)
+ */
+static int ntfs_zero_range(struct inode *inode, u64 vbo, u64 vbo_to)
+{
+	int err = 0;
+	struct address_space *mapping = inode->i_mapping;
+	u32 blocksize = 1 << inode->i_blkbits;
+	pgoff_t idx = vbo >> PAGE_SHIFT;
+	u32 z_start = vbo & (PAGE_SIZE - 1);
+	pgoff_t idx_end = (vbo_to + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	loff_t page_off;
+	struct buffer_head *head, *bh;
+	u32 bh_next, bh_off, z_end;
+	sector_t iblock;
+	struct page *page;
+
+	for (; idx < idx_end; idx += 1, z_start = 0) {
+		page_off = (loff_t)idx << PAGE_SHIFT;
+		z_end = (page_off + PAGE_SIZE) > vbo_to ? (vbo_to - page_off)
+							: PAGE_SIZE;
+		iblock = page_off >> inode->i_blkbits;
+
+		page = find_or_create_page(mapping, idx,
+					   mapping_gfp_constraint(mapping,
+								  ~__GFP_FS));
+		if (!page)
+			return -ENOMEM;
+
+		if (!page_has_buffers(page))
+			create_empty_buffers(page, blocksize, 0);
+
+		bh = head = page_buffers(page);
+		bh_off = 0;
+		do {
+			bh_next = bh_off + blocksize;
+
+			if (bh_next <= z_start || bh_off >= z_end)
+				continue;
+
+			if (!buffer_mapped(bh)) {
+				ntfs_get_block(inode, iblock, bh, 0);
+				/* unmapped? It's a hole - nothing to do */
+				if (!buffer_mapped(bh))
+					continue;
+			}
+
+			/* Ok, it's mapped. Make sure it's up-to-date */
+			if (PageUptodate(page))
+				set_buffer_uptodate(bh);
+
+			if (!buffer_uptodate(bh)) {
+				lock_buffer(bh);
+				bh->b_end_io = end_buffer_read_sync;
+				get_bh(bh);
+				submit_bh(REQ_OP_READ, 0, bh);
+
+				wait_on_buffer(bh);
+				if (!buffer_uptodate(bh)) {
+					unlock_page(page);
+					put_page(page);
+					err = -EIO;
+					goto out;
+				}
+			}
+
+			mark_buffer_dirty(bh);
+
+		} while (bh_off = bh_next, iblock += 1,
+			 head != (bh = bh->b_this_page));
+
+		zero_user_segment(page, z_start, z_end);
+
+		unlock_page(page);
+		put_page(page);
+		cond_resched();
+	}
+out:
+	mark_inode_dirty(inode);
+	return err;
+}
+
+/*
+ * ntfs_sparse_cluster
+ *
+ * Helper function to zero a new allocated clusters
+ * NOTE: 512 <= cluster size <= 2M
+ */
+void ntfs_sparse_cluster(struct inode *inode, struct page *page0, CLST vcn,
+			 CLST len)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
+	u64 vbo = (u64)vcn << sbi->cluster_bits;
+	u64 bytes = (u64)len << sbi->cluster_bits;
+	u32 blocksize = 1 << inode->i_blkbits;
+	pgoff_t idx0 = page0 ? page0->index : -1;
+	loff_t vbo_clst = vbo & sbi->cluster_mask_inv;
+	loff_t end = ntfs_up_cluster(sbi, vbo + bytes);
+	pgoff_t idx = vbo_clst >> PAGE_SHIFT;
+	u32 from = vbo_clst & (PAGE_SIZE - 1);
+	pgoff_t idx_end = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	loff_t page_off;
+	u32 to;
+	bool partial;
+	struct page *page;
+
+	for (; idx < idx_end; idx += 1, from = 0) {
+		page = idx == idx0 ? page0 : grab_cache_page(mapping, idx);
+
+		if (!page)
+			continue;
+
+		page_off = (loff_t)idx << PAGE_SHIFT;
+		to = (page_off + PAGE_SIZE) > end ? (end - page_off)
+						  : PAGE_SIZE;
+		partial = false;
+
+		if ((from || PAGE_SIZE != to) &&
+		    likely(!page_has_buffers(page))) {
+			create_empty_buffers(page, blocksize, 0);
+		}
+
+		if (page_has_buffers(page)) {
+			struct buffer_head *head, *bh;
+			u32 bh_off = 0;
+
+			bh = head = page_buffers(page);
+			do {
+				u32 bh_next = bh_off + blocksize;
+
+				if (from <= bh_off && bh_next <= to) {
+					set_buffer_uptodate(bh);
+					mark_buffer_dirty(bh);
+				} else if (!buffer_uptodate(bh)) {
+					partial = true;
+				}
+				bh_off = bh_next;
+			} while (head != (bh = bh->b_this_page));
+		}
+
+		zero_user_segment(page, from, to);
+
+		if (!partial) {
+			if (!PageUptodate(page))
+				SetPageUptodate(page);
+			set_page_dirty(page);
+		}
+
+		if (idx != idx0) {
+			unlock_page(page);
+			put_page(page);
+		}
+		cond_resched();
+	}
+	mark_inode_dirty(inode);
+}
+
+/*
+ * file_operations::mmap
+ */
+static int ntfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	struct ntfs_inode *ni = ntfs_i(inode);
+	u64 from = ((u64)vma->vm_pgoff << PAGE_SHIFT);
+	bool rw = vma->vm_flags & VM_WRITE;
+	int err;
+
+	if (is_encrypted(ni)) {
+		ntfs_inode_warn(inode, "mmap encrypted not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (is_dedup(ni)) {
+		ntfs_inode_warn(inode, "mmap deduplicated not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (is_compressed(ni) && rw) {
+		ntfs_inode_warn(inode, "mmap(write) compressed not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (rw) {
+		u64 to = min_t(loff_t, i_size_read(inode),
+			       from + vma->vm_end - vma->vm_start);
+
+		if (is_sparsed(ni)) {
+			/* allocate clusters for rw map */
+			struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
+			CLST lcn, len;
+			CLST vcn = from >> sbi->cluster_bits;
+			CLST end = bytes_to_cluster(sbi, to);
+			bool new;
+
+			for (; vcn < end; vcn += len) {
+				err = attr_data_get_block(ni, vcn, 1, &lcn,
+							  &len, &new);
+				if (err)
+					goto out;
+
+				if (!new)
+					continue;
+				ntfs_sparse_cluster(inode, NULL, vcn, 1);
+			}
+		}
+
+		if (ni->i_valid < to) {
+			if (!inode_trylock(inode)) {
+				err = -EAGAIN;
+				goto out;
+			}
+			err = ntfs_extend_initialized_size(file, ni,
+							   ni->i_valid, to);
+			inode_unlock(inode);
+			if (err)
+				goto out;
+		}
+	}
+
+	err = generic_file_mmap(file, vma);
+out:
+	return err;
+}
+
+static int ntfs_extend(struct inode *inode, loff_t pos, size_t count,
+		       struct file *file)
+{
+	struct ntfs_inode *ni = ntfs_i(inode);
+	struct address_space *mapping = inode->i_mapping;
+	loff_t end = pos + count;
+	bool extend_init = file && pos > ni->i_valid;
+	int err;
+
+	if (end <= inode->i_size && !extend_init)
+		return 0;
+
+	/*mark rw ntfs as dirty. it will be cleared at umount*/
+	ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_DIRTY);
+
+	if (end > inode->i_size) {
+		err = ntfs_set_size(inode, end);
+		if (err)
+			goto out;
+		inode->i_size = end;
+	}
+
+	if (extend_init && !is_compressed(ni)) {
+		err = ntfs_extend_initialized_size(file, ni, ni->i_valid, pos);
+		if (err)
+			goto out;
+	} else {
+		err = 0;
+	}
+
+	inode->i_ctime = inode->i_mtime = current_time(inode);
+	mark_inode_dirty(inode);
+
+	if (IS_SYNC(inode)) {
+		int err2;
+
+		err = filemap_fdatawrite_range(mapping, pos, end - 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, pos, end - 1);
+	}
+
+out:
+	return err;
+}
+
+static int ntfs_truncate(struct inode *inode, loff_t new_size)
+{
+	struct super_block *sb = inode->i_sb;
+	struct ntfs_inode *ni = ntfs_i(inode);
+	int err, dirty = 0;
+	u64 new_valid;
+
+	if (!S_ISREG(inode->i_mode))
+		return 0;
+
+	if (is_compressed(ni)) {
+		if (ni->i_valid > new_size)
+			ni->i_valid = new_size;
+	} else {
+		err = block_truncate_page(inode->i_mapping, new_size,
+					  ntfs_get_block);
+		if (err)
+			return err;
+	}
+
+	new_valid = ntfs_up_block(sb, min_t(u64, ni->i_valid, new_size));
+
+	ni_lock(ni);
+
+	truncate_setsize(inode, new_size);
+
+	down_write(&ni->file.run_lock);
+	err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run, new_size,
+			    &new_valid, true, NULL);
+	up_write(&ni->file.run_lock);
+
+	if (new_valid < ni->i_valid)
+		ni->i_valid = new_valid;
+
+	ni_unlock(ni);
+
+	ni->std_fa |= FILE_ATTRIBUTE_ARCHIVE;
+	inode->i_ctime = inode->i_mtime = current_time(inode);
+	if (!IS_DIRSYNC(inode)) {
+		dirty = 1;
+	} else {
+		err = ntfs_sync_inode(inode);
+		if (err)
+			return err;
+	}
+
+	if (dirty)
+		mark_inode_dirty(inode);
+
+	/*ntfs_flush_inodes(inode->i_sb, inode, NULL);*/
+
+	return 0;
+}
+
+/*
+ * Preallocate space for a file. This implements ntfs's fallocate file
+ * operation, which gets called from sys_fallocate system call. User
+ * space requests 'len' bytes at 'vbo'. 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 ntfs_fallocate(struct file *file, int mode, loff_t vbo, loff_t len)
+{
+	struct inode *inode = file->f_mapping->host;
+	struct super_block *sb = inode->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	struct ntfs_inode *ni = ntfs_i(inode);
+	loff_t end = vbo + len;
+	loff_t vbo_down = round_down(vbo, PAGE_SIZE);
+	loff_t i_size;
+	int err;
+
+	/* No support for dir */
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	/* Return error if mode is not supported */
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+		     FALLOC_FL_COLLAPSE_RANGE)) {
+		ntfs_inode_warn(inode, "fallocate(0x%x) is not supported",
+				mode);
+		return -EOPNOTSUPP;
+	}
+
+	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
+
+	inode_lock(inode);
+	i_size = inode->i_size;
+
+	if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
+		/* should never be here, see ntfs_file_open*/
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	if (mode & FALLOC_FL_PUNCH_HOLE) {
+		u32 frame_size;
+		loff_t mask, vbo_a, end_a, tmp;
+
+		if (!(mode & FALLOC_FL_KEEP_SIZE)) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		err = filemap_write_and_wait_range(inode->i_mapping, vbo,
+						   end - 1);
+		if (err)
+			goto out;
+
+		err = filemap_write_and_wait_range(inode->i_mapping, end,
+						   LLONG_MAX);
+		if (err)
+			goto out;
+
+		inode_dio_wait(inode);
+
+		truncate_pagecache(inode, vbo_down);
+
+		if (!is_sparsed(ni) && !is_compressed(ni)) {
+			/* normal file */
+			err = ntfs_zero_range(inode, vbo, end);
+			goto out;
+		}
+
+		ni_lock(ni);
+		err = attr_punch_hole(ni, vbo, len, &frame_size);
+		ni_unlock(ni);
+		if (err != E_NTFS_NOTALIGNED)
+			goto out;
+
+		/* process not aligned punch */
+		mask = frame_size - 1;
+		vbo_a = (vbo + mask) & ~mask;
+		end_a = end & ~mask;
+
+		tmp = min(vbo_a, end);
+		if (tmp > vbo) {
+			err = ntfs_zero_range(inode, vbo, tmp);
+			if (err)
+				goto out;
+		}
+
+		if (vbo < end_a && end_a < end) {
+			err = ntfs_zero_range(inode, end_a, end);
+			if (err)
+				goto out;
+		}
+
+		/* Aligned punch_hole */
+		if (end_a > vbo_a) {
+			ni_lock(ni);
+			err = attr_punch_hole(ni, vbo_a, end_a - vbo_a, NULL);
+			ni_unlock(ni);
+		}
+	} else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
+		if (mode & ~FALLOC_FL_COLLAPSE_RANGE) {
+			err = -EINVAL;
+			goto out;
+		}
+
+		/*
+		 * Write tail of the last page before removed range since
+		 * it will get removed from the page cache below.
+		 */
+		err = filemap_write_and_wait_range(inode->i_mapping, vbo_down,
+						   vbo);
+		if (err)
+			goto out;
+
+		/*
+		 * Write data that will be shifted to preserve them
+		 * when discarding page cache below
+		 */
+		err = filemap_write_and_wait_range(inode->i_mapping, end,
+						   LLONG_MAX);
+		if (err)
+			goto out;
+
+		/* Wait for existing dio to complete */
+		inode_dio_wait(inode);
+
+		truncate_pagecache(inode, vbo_down);
+
+		ni_lock(ni);
+		err = attr_collapse_range(ni, vbo, len);
+		ni_unlock(ni);
+	} else {
+		/*
+		 * normal file: allocate clusters, do not change 'valid' size
+		 */
+		err = ntfs_set_size(inode, max(end, i_size));
+		if (err)
+			goto out;
+
+		if (is_sparsed(ni) || is_compressed(ni)) {
+			CLST vcn_v = ni->i_valid >> sbi->cluster_bits;
+			CLST vcn = vbo >> sbi->cluster_bits;
+			CLST cend = bytes_to_cluster(sbi, end);
+			CLST lcn, clen;
+			bool new;
+
+			/*
+			 * allocate but not zero new clusters (see below comments)
+			 * this breaks security (one can read unused on-disk areas)
+			 * zeroing these clusters may be too long
+			 * may be we should check here for root rights?
+			 */
+			for (; vcn < cend; vcn += clen) {
+				err = attr_data_get_block(ni, vcn, cend - vcn,
+							  &lcn, &clen, &new);
+				if (err)
+					goto out;
+				if (!new || vcn >= vcn_v)
+					continue;
+
+				/*
+				 * Unwritten area
+				 * NTFS is not able to store several unwritten areas
+				 * Activate 'ntfs_sparse_cluster' to zero new allocated clusters
+				 *
+				 * Dangerous in case:
+				 * 1G of sparsed clusters + 1 cluster of data =>
+				 * valid_size == 1G + 1 cluster
+				 * fallocate(1G) will zero 1G and this can be very long
+				 * xfstest 016/086 will fail without 'ntfs_sparse_cluster'
+				 */
+				ntfs_sparse_cluster(inode, NULL, vcn,
+						    min(vcn_v - vcn, clen));
+			}
+		}
+
+		if (mode & FALLOC_FL_KEEP_SIZE) {
+			ni_lock(ni);
+			/*true - keep preallocated*/
+			err = attr_set_size(ni, ATTR_DATA, NULL, 0,
+					    &ni->file.run, i_size, &ni->i_valid,
+					    true, NULL);
+			ni_unlock(ni);
+		}
+	}
+
+out:
+	if (err == -EFBIG)
+		err = -ENOSPC;
+
+	if (!err) {
+		inode->i_ctime = inode->i_mtime = current_time(inode);
+		mark_inode_dirty(inode);
+	}
+
+	inode_unlock(inode);
+	return err;
+}
+
+/*
+ * inode_operations::setattr
+ */
+int ntfs3_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
+		  struct iattr *attr)
+{
+	struct super_block *sb = dentry->d_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	struct inode *inode = d_inode(dentry);
+	struct ntfs_inode *ni = ntfs_i(inode);
+	u32 ia_valid = attr->ia_valid;
+	umode_t mode = inode->i_mode;
+	int err;
+
+	if (sbi->options.no_acs_rules) {
+		/* "no access rules" - force any changes of time etc. */
+		attr->ia_valid |= ATTR_FORCE;
+		/* and disable for editing some attributes */
+		attr->ia_valid &= ~(ATTR_UID | ATTR_GID | ATTR_MODE);
+		ia_valid = attr->ia_valid;
+	}
+
+	err = setattr_prepare(mnt_userns, dentry, attr);
+	if (err)
+		goto out;
+
+	if (ia_valid & ATTR_SIZE) {
+		loff_t oldsize = inode->i_size;
+
+		if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
+			/* should never be here, see ntfs_file_open*/
+			err = -EOPNOTSUPP;
+			goto out;
+		}
+		inode_dio_wait(inode);
+
+		if (attr->ia_size < oldsize)
+			err = ntfs_truncate(inode, attr->ia_size);
+		else if (attr->ia_size > oldsize)
+			err = ntfs_extend(inode, attr->ia_size, 0, NULL);
+
+		if (err)
+			goto out;
+
+		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
+	}
+
+	setattr_copy(mnt_userns, inode, attr);
+
+	if (mode != inode->i_mode) {
+		err = ntfs_acl_chmod(mnt_userns, inode);
+		if (err)
+			goto out;
+
+		/* linux 'w' -> windows 'ro' */
+		if (0222 & inode->i_mode)
+			ni->std_fa &= ~FILE_ATTRIBUTE_READONLY;
+		else
+			ni->std_fa |= FILE_ATTRIBUTE_READONLY;
+	}
+
+	if (ia_valid & (ATTR_UID | ATTR_GID | ATTR_MODE))
+		ntfs_save_wsl_perm(inode);
+	mark_inode_dirty(inode);
+out:
+	return err;
+}
+
+static ssize_t ntfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	ssize_t err;
+	size_t count = iov_iter_count(iter);
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_mapping->host;
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (is_encrypted(ni)) {
+		ntfs_inode_warn(inode, "encrypted i/o not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (is_compressed(ni) && (iocb->ki_flags & IOCB_DIRECT)) {
+		ntfs_inode_warn(inode, "direct i/o + compressed not supported");
+		return -EOPNOTSUPP;
+	}
+
+#ifndef CONFIG_NTFS3_LZX_XPRESS
+	if (ni->ni_flags & NI_FLAG_COMPRESSED_MASK) {
+		ntfs_inode_warn(
+			inode,
+			"activate CONFIG_NTFS3_LZX_XPRESS to read external compressed files");
+		return -EOPNOTSUPP;
+	}
+#endif
+
+	if (is_dedup(ni)) {
+		ntfs_inode_warn(inode, "read deduplicated not supported");
+		return -EOPNOTSUPP;
+	}
+
+	err = count ? generic_file_read_iter(iocb, iter) : 0;
+
+	return err;
+}
+
+/* returns array of locked pages */
+static int ntfs_get_frame_pages(struct address_space *mapping, pgoff_t index,
+				struct page **pages, u32 pages_per_frame,
+				bool *frame_uptodate)
+{
+	gfp_t gfp_mask = mapping_gfp_mask(mapping);
+	u32 npages;
+
+	*frame_uptodate = true;
+
+	for (npages = 0; npages < pages_per_frame; npages++, index++) {
+		struct page *page;
+
+		page = find_or_create_page(mapping, index, gfp_mask);
+		if (!page) {
+			while (npages--) {
+				page = pages[npages];
+				unlock_page(page);
+				put_page(page);
+			}
+
+			return -ENOMEM;
+		}
+
+		if (!PageUptodate(page))
+			*frame_uptodate = false;
+
+		pages[npages] = page;
+	}
+
+	return 0;
+}
+
+/*helper for ntfs_file_write_iter (compressed files)*/
+static ssize_t ntfs_compress_write(struct kiocb *iocb, struct iov_iter *from)
+{
+	int err;
+	struct file *file = iocb->ki_filp;
+	size_t count = iov_iter_count(from);
+	loff_t pos = iocb->ki_pos;
+	struct inode *inode = file_inode(file);
+	loff_t i_size = inode->i_size;
+	struct address_space *mapping = inode->i_mapping;
+	struct ntfs_inode *ni = ntfs_i(inode);
+	u64 valid = ni->i_valid;
+	struct ntfs_sb_info *sbi = ni->mi.sbi;
+	struct page *page, **pages = NULL;
+	size_t written = 0;
+	u8 frame_bits = NTFS_LZNT_CUNIT + sbi->cluster_bits;
+	u32 frame_size = 1u << frame_bits;
+	u32 pages_per_frame = frame_size >> PAGE_SHIFT;
+	u32 ip, off;
+	CLST frame;
+	u64 frame_vbo;
+	pgoff_t index;
+	bool frame_uptodate;
+
+	if (frame_size < PAGE_SIZE) {
+		/*
+		 * frame_size == 8K if cluster 512
+		 * frame_size == 64K if cluster 4096
+		 */
+		ntfs_inode_warn(inode, "page size is bigger than frame size");
+		return -EOPNOTSUPP;
+	}
+
+	pages = ntfs_malloc(pages_per_frame * sizeof(struct page *));
+	if (!pages)
+		return -ENOMEM;
+
+	current->backing_dev_info = inode_to_bdi(inode);
+	err = file_remove_privs(file);
+	if (err)
+		goto out;
+
+	err = file_update_time(file);
+	if (err)
+		goto out;
+
+	/* zero range [valid : pos) */
+	while (valid < pos) {
+		CLST lcn, clen;
+
+		frame = valid >> frame_bits;
+		frame_vbo = valid & ~(frame_size - 1);
+		off = valid & (frame_size - 1);
+
+		err = attr_data_get_block(ni, frame << NTFS_LZNT_CUNIT, 0, &lcn,
+					  &clen, NULL);
+		if (err)
+			goto out;
+
+		if (lcn == SPARSE_LCN) {
+			ni->i_valid = valid =
+				frame_vbo + ((u64)clen << sbi->cluster_bits);
+			continue;
+		}
+
+		/* Load full frame */
+		err = ntfs_get_frame_pages(mapping, frame_vbo >> PAGE_SHIFT,
+					   pages, pages_per_frame,
+					   &frame_uptodate);
+		if (err)
+			goto out;
+
+		if (!frame_uptodate && off) {
+			err = ni_read_frame(ni, frame_vbo, pages,
+					    pages_per_frame);
+			if (err) {
+				for (ip = 0; ip < pages_per_frame; ip++) {
+					page = pages[ip];
+					unlock_page(page);
+					put_page(page);
+				}
+				goto out;
+			}
+		}
+
+		ip = off >> PAGE_SHIFT;
+		off = offset_in_page(valid);
+		for (; ip < pages_per_frame; ip++, off = 0) {
+			page = pages[ip];
+			zero_user_segment(page, off, PAGE_SIZE);
+			flush_dcache_page(page);
+			SetPageUptodate(page);
+		}
+
+		ni_lock(ni);
+		err = ni_write_frame(ni, pages, pages_per_frame);
+		ni_unlock(ni);
+
+		for (ip = 0; ip < pages_per_frame; ip++) {
+			page = pages[ip];
+			SetPageUptodate(page);
+			unlock_page(page);
+			put_page(page);
+		}
+
+		if (err)
+			goto out;
+
+		ni->i_valid = valid = frame_vbo + frame_size;
+	}
+
+	/* copy user data [pos : pos + count) */
+	while (count) {
+		size_t copied, bytes;
+
+		off = pos & (frame_size - 1);
+		bytes = frame_size - off;
+		if (bytes > count)
+			bytes = count;
+
+		frame = pos >> frame_bits;
+		frame_vbo = pos & ~(frame_size - 1);
+		index = frame_vbo >> PAGE_SHIFT;
+
+		if (unlikely(iov_iter_fault_in_readable(from, bytes))) {
+			err = -EFAULT;
+			goto out;
+		}
+
+		/* Load full frame */
+		err = ntfs_get_frame_pages(mapping, index, pages,
+					   pages_per_frame, &frame_uptodate);
+		if (err)
+			goto out;
+
+		if (!frame_uptodate) {
+			loff_t to = pos + bytes;
+
+			if (off || (to < i_size && (to & (frame_size - 1)))) {
+				err = ni_read_frame(ni, frame_vbo, pages,
+						    pages_per_frame);
+				if (err) {
+					for (ip = 0; ip < pages_per_frame;
+					     ip++) {
+						page = pages[ip];
+						unlock_page(page);
+						put_page(page);
+					}
+					goto out;
+				}
+			}
+		}
+
+		WARN_ON(!bytes);
+		copied = 0;
+		ip = off >> PAGE_SHIFT;
+		off = offset_in_page(pos);
+
+		/* copy user data to pages */
+		for (;;) {
+			size_t cp, tail = PAGE_SIZE - off;
+
+			page = pages[ip];
+			cp = copy_page_from_iter_atomic(page, off,
+							min(tail, bytes), from);
+			flush_dcache_page(page);
+
+			copied += cp;
+			bytes -= cp;
+			if (!bytes || !cp)
+				break;
+
+			if (cp < tail) {
+				off += cp;
+			} else {
+				ip++;
+				off = 0;
+			}
+		}
+
+		ni_lock(ni);
+		err = ni_write_frame(ni, pages, pages_per_frame);
+		ni_unlock(ni);
+
+		for (ip = 0; ip < pages_per_frame; ip++) {
+			page = pages[ip];
+			ClearPageDirty(page);
+			SetPageUptodate(page);
+			unlock_page(page);
+			put_page(page);
+		}
+
+		if (err)
+			goto out;
+
+		/*
+		 * We can loop for a long time in here. Be nice and allow
+		 * us to schedule out to avoid softlocking if preempt
+		 * is disabled.
+		 */
+		cond_resched();
+
+		pos += copied;
+		written += copied;
+
+		count = iov_iter_count(from);
+	}
+
+out:
+	ntfs_free(pages);
+
+	current->backing_dev_info = NULL;
+
+	if (err < 0)
+		return err;
+
+	iocb->ki_pos += written;
+	if (iocb->ki_pos > ni->i_valid)
+		ni->i_valid = iocb->ki_pos;
+
+	return written;
+}
+
+/*
+ * file_operations::write_iter
+ */
+static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct address_space *mapping = file->f_mapping;
+	struct inode *inode = mapping->host;
+	ssize_t ret;
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (is_encrypted(ni)) {
+		ntfs_inode_warn(inode, "encrypted i/o not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (is_compressed(ni) && (iocb->ki_flags & IOCB_DIRECT)) {
+		ntfs_inode_warn(inode, "direct i/o + compressed not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (is_dedup(ni)) {
+		ntfs_inode_warn(inode, "write into deduplicated not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (!inode_trylock(inode)) {
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			return -EAGAIN;
+		inode_lock(inode);
+	}
+
+	ret = generic_write_checks(iocb, from);
+	if (ret <= 0)
+		goto out;
+
+	if (WARN_ON(ni->ni_flags & NI_FLAG_COMPRESSED_MASK)) {
+		/* should never be here, see ntfs_file_open*/
+		ret = -EOPNOTSUPP;
+		goto out;
+	}
+
+	ret = ntfs_extend(inode, iocb->ki_pos, ret, file);
+	if (ret)
+		goto out;
+
+	ret = is_compressed(ni) ? ntfs_compress_write(iocb, from)
+				: __generic_file_write_iter(iocb, from);
+
+out:
+	inode_unlock(inode);
+
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
+
+	return ret;
+}
+
+/*
+ * file_operations::open
+ */
+int ntfs_file_open(struct inode *inode, struct file *file)
+{
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (unlikely((is_compressed(ni) || is_encrypted(ni)) &&
+		     (file->f_flags & O_DIRECT))) {
+		return -EOPNOTSUPP;
+	}
+
+	/* Decompress "external compressed" file if opened for rw */
+	if ((ni->ni_flags & NI_FLAG_COMPRESSED_MASK) &&
+	    (file->f_flags & (O_WRONLY | O_RDWR | O_TRUNC))) {
+#ifdef CONFIG_NTFS3_LZX_XPRESS
+		int err = ni_decompress_file(ni);
+
+		if (err)
+			return err;
+#else
+		ntfs_inode_warn(
+			inode,
+			"activate CONFIG_NTFS3_LZX_XPRESS to write external compressed files");
+		return -EOPNOTSUPP;
+#endif
+	}
+
+	return generic_file_open(inode, file);
+}
+
+/*
+ * file_operations::release
+ */
+static int ntfs_file_release(struct inode *inode, struct file *file)
+{
+	struct ntfs_inode *ni = ntfs_i(inode);
+	struct ntfs_sb_info *sbi = ni->mi.sbi;
+	int err = 0;
+
+	/* if we are the last writer on the inode, drop the block reservation */
+	if (sbi->options.prealloc && ((file->f_mode & FMODE_WRITE) &&
+				      atomic_read(&inode->i_writecount) == 1)) {
+		ni_lock(ni);
+		down_write(&ni->file.run_lock);
+
+		err = attr_set_size(ni, ATTR_DATA, NULL, 0, &ni->file.run,
+				    inode->i_size, &ni->i_valid, false, NULL);
+
+		up_write(&ni->file.run_lock);
+		ni_unlock(ni);
+	}
+	return err;
+}
+
+/* file_operations::fiemap */
+int ntfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+		__u64 start, __u64 len)
+{
+	int err;
+	struct ntfs_inode *ni = ntfs_i(inode);
+
+	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR)
+		return -EOPNOTSUPP;
+
+	ni_lock(ni);
+
+	err = ni_fiemap(ni, fieinfo, start, len);
+
+	ni_unlock(ni);
+
+	return err;
+}
+
+// clang-format off
+const struct inode_operations ntfs_file_inode_operations = {
+	.getattr	= ntfs_getattr,
+	.setattr	= ntfs3_setattr,
+	.listxattr	= ntfs_listxattr,
+	.permission	= ntfs_permission,
+	.get_acl	= ntfs_get_acl,
+	.set_acl	= ntfs_set_acl,
+	.fiemap		= ntfs_fiemap,
+};
+
+const struct file_operations ntfs_file_operations = {
+	.llseek		= generic_file_llseek,
+	.read_iter	= ntfs_file_read_iter,
+	.write_iter	= ntfs_file_write_iter,
+	.unlocked_ioctl = ntfs_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ntfs_compat_ioctl,
+#endif
+	.splice_read	= generic_file_splice_read,
+	.mmap		= ntfs_file_mmap,
+	.open		= ntfs_file_open,
+	.fsync		= generic_file_fsync,
+	.splice_write	= iter_file_splice_write,
+	.fallocate	= ntfs_fallocate,
+	.release	= ntfs_file_release,
+};
+// clang-format on