fs/ntfs3: Add file operations and implementation

This adds file operations and implementation

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

6 files changed, 7178 insertions, 0 deletions

diff --git a/fs/ntfs3/dir.c b/fs/ntfs3/dir.c
new file mode 100644
index 000000000000..d36d7fbc2b1d
--- /dev/null
+++ b/fs/ntfs3/dir.c
@@ -0,0 +1,596 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ *  directory handling functions for ntfs-based filesystems
+ *
+ */
+#include <linux/blkdev.h>
+#include <linux/buffer_head.h>
+#include <linux/fs.h>
+#include <linux/iversion.h>
+#include <linux/nls.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+/*
+ * Convert little endian utf16 to nls string
+ */
+int ntfs_utf16_to_nls(struct ntfs_sb_info *sbi, const struct le_str *uni,
+		      u8 *buf, int buf_len)
+{
+	int ret, uni_len, warn;
+	const __le16 *ip;
+	u8 *op;
+	struct nls_table *nls = sbi->options.nls;
+
+	static_assert(sizeof(wchar_t) == sizeof(__le16));
+
+	if (!nls) {
+		/* utf16 -> utf8 */
+		ret = utf16s_to_utf8s((wchar_t *)uni->name, uni->len,
+				      UTF16_LITTLE_ENDIAN, buf, buf_len);
+		buf[ret] = '\0';
+		return ret;
+	}
+
+	ip = uni->name;
+	op = buf;
+	uni_len = uni->len;
+	warn = 0;
+
+	while (uni_len--) {
+		u16 ec;
+		int charlen;
+		char dump[5];
+
+		if (buf_len < NLS_MAX_CHARSET_SIZE) {
+			ntfs_warn(sbi->sb,
+				  "filename was truncated while converting.");
+			break;
+		}
+
+		ec = le16_to_cpu(*ip++);
+		charlen = nls->uni2char(ec, op, buf_len);
+
+		if (charlen > 0) {
+			op += charlen;
+			buf_len -= charlen;
+			continue;
+		}
+
+		*op++ = '_';
+		buf_len -= 1;
+		if (warn)
+			continue;
+
+		warn = 1;
+		hex_byte_pack(&dump[0], ec >> 8);
+		hex_byte_pack(&dump[2], ec);
+		dump[4] = 0;
+
+		ntfs_err(sbi->sb, "failed to convert \"%s\" to %s", dump,
+			 nls->charset);
+	}
+
+	*op = '\0';
+	return op - buf;
+}
+
+// clang-format off
+#define PLANE_SIZE	0x00010000
+
+#define SURROGATE_PAIR	0x0000d800
+#define SURROGATE_LOW	0x00000400
+#define SURROGATE_BITS	0x000003ff
+// clang-format on
+
+/*
+ * modified version of put_utf16 from fs/nls/nls_base.c
+ * is sparse warnings free
+ */
+static inline void put_utf16(wchar_t *s, unsigned int c,
+			     enum utf16_endian endian)
+{
+	static_assert(sizeof(wchar_t) == sizeof(__le16));
+	static_assert(sizeof(wchar_t) == sizeof(__be16));
+
+	switch (endian) {
+	default:
+		*s = (wchar_t)c;
+		break;
+	case UTF16_LITTLE_ENDIAN:
+		*(__le16 *)s = __cpu_to_le16(c);
+		break;
+	case UTF16_BIG_ENDIAN:
+		*(__be16 *)s = __cpu_to_be16(c);
+		break;
+	}
+}
+
+/*
+ * modified version of 'utf8s_to_utf16s' allows to
+ * detect -ENAMETOOLONG without writing out of expected maximum
+ */
+static int _utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian,
+			    wchar_t *pwcs, int maxout)
+{
+	u16 *op;
+	int size;
+	unicode_t u;
+
+	op = pwcs;
+	while (inlen > 0 && *s) {
+		if (*s & 0x80) {
+			size = utf8_to_utf32(s, inlen, &u);
+			if (size < 0)
+				return -EINVAL;
+			s += size;
+			inlen -= size;
+
+			if (u >= PLANE_SIZE) {
+				if (maxout < 2)
+					return -ENAMETOOLONG;
+
+				u -= PLANE_SIZE;
+				put_utf16(op++,
+					  SURROGATE_PAIR |
+						  ((u >> 10) & SURROGATE_BITS),
+					  endian);
+				put_utf16(op++,
+					  SURROGATE_PAIR | SURROGATE_LOW |
+						  (u & SURROGATE_BITS),
+					  endian);
+				maxout -= 2;
+			} else {
+				if (maxout < 1)
+					return -ENAMETOOLONG;
+
+				put_utf16(op++, u, endian);
+				maxout--;
+			}
+		} else {
+			if (maxout < 1)
+				return -ENAMETOOLONG;
+
+			put_utf16(op++, *s++, endian);
+			inlen--;
+			maxout--;
+		}
+	}
+	return op - pwcs;
+}
+
+/*
+ * Convert input string to utf16
+ *
+ * name, name_len - input name
+ * uni, max_ulen - destination memory
+ * endian - endian of target utf16 string
+ *
+ * This function is called:
+ * - to create ntfs name
+ * - to create symlink
+ *
+ * returns utf16 string length or error (if negative)
+ */
+int ntfs_nls_to_utf16(struct ntfs_sb_info *sbi, const u8 *name, u32 name_len,
+		      struct cpu_str *uni, u32 max_ulen,
+		      enum utf16_endian endian)
+{
+	int ret, slen;
+	const u8 *end;
+	struct nls_table *nls = sbi->options.nls;
+	u16 *uname = uni->name;
+
+	static_assert(sizeof(wchar_t) == sizeof(u16));
+
+	if (!nls) {
+		/* utf8 -> utf16 */
+		ret = _utf8s_to_utf16s(name, name_len, endian, uname, max_ulen);
+		uni->len = ret;
+		return ret;
+	}
+
+	for (ret = 0, end = name + name_len; name < end; ret++, name += slen) {
+		if (ret >= max_ulen)
+			return -ENAMETOOLONG;
+
+		slen = nls->char2uni(name, end - name, uname + ret);
+		if (!slen)
+			return -EINVAL;
+		if (slen < 0)
+			return slen;
+	}
+
+#ifdef __BIG_ENDIAN
+	if (endian == UTF16_LITTLE_ENDIAN) {
+		int i = ret;
+
+		while (i--) {
+			__cpu_to_le16s(uname);
+			uname++;
+		}
+	}
+#else
+	if (endian == UTF16_BIG_ENDIAN) {
+		int i = ret;
+
+		while (i--) {
+			__cpu_to_be16s(uname);
+			uname++;
+		}
+	}
+#endif
+
+	uni->len = ret;
+	return ret;
+}
+
+/* helper function */
+struct inode *dir_search_u(struct inode *dir, const struct cpu_str *uni,
+			   struct ntfs_fnd *fnd)
+{
+	int err = 0;
+	struct super_block *sb = dir->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct NTFS_DE *e;
+	int diff;
+	struct inode *inode = NULL;
+	struct ntfs_fnd *fnd_a = NULL;
+
+	if (!fnd) {
+		fnd_a = fnd_get();
+		if (!fnd_a) {
+			err = -ENOMEM;
+			goto out;
+		}
+		fnd = fnd_a;
+	}
+
+	err = indx_find(&ni->dir, ni, NULL, uni, 0, sbi, &diff, &e, fnd);
+
+	if (err)
+		goto out;
+
+	if (diff) {
+		err = -ENOENT;
+		goto out;
+	}
+
+	inode = ntfs_iget5(sb, &e->ref, uni);
+	if (!IS_ERR(inode) && is_bad_inode(inode)) {
+		iput(inode);
+		err = -EINVAL;
+	}
+out:
+	fnd_put(fnd_a);
+
+	return err == -ENOENT ? NULL : err ? ERR_PTR(err) : inode;
+}
+
+static inline int ntfs_filldir(struct ntfs_sb_info *sbi, struct ntfs_inode *ni,
+			       const struct NTFS_DE *e, u8 *name,
+			       struct dir_context *ctx)
+{
+	const struct ATTR_FILE_NAME *fname;
+	unsigned long ino;
+	int name_len;
+	u32 dt_type;
+
+	fname = Add2Ptr(e, sizeof(struct NTFS_DE));
+
+	if (fname->type == FILE_NAME_DOS)
+		return 0;
+
+	if (!mi_is_ref(&ni->mi, &fname->home))
+		return 0;
+
+	ino = ino_get(&e->ref);
+
+	if (ino == MFT_REC_ROOT)
+		return 0;
+
+	/* Skip meta files ( unless option to show metafiles is set ) */
+	if (!sbi->options.showmeta && ntfs_is_meta_file(sbi, ino))
+		return 0;
+
+	if (sbi->options.nohidden && (fname->dup.fa & FILE_ATTRIBUTE_HIDDEN))
+		return 0;
+
+	name_len = ntfs_utf16_to_nls(sbi, (struct le_str *)&fname->name_len,
+				     name, PATH_MAX);
+	if (name_len <= 0) {
+		ntfs_warn(sbi->sb, "failed to convert name for inode %lx.",
+			  ino);
+		return 0;
+	}
+
+	dt_type = (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY) ? DT_DIR : DT_REG;
+
+	return !dir_emit(ctx, (s8 *)name, name_len, ino, dt_type);
+}
+
+/*
+ * ntfs_read_hdr
+ *
+ * helper function 'ntfs_readdir'
+ */
+static int ntfs_read_hdr(struct ntfs_sb_info *sbi, struct ntfs_inode *ni,
+			 const struct INDEX_HDR *hdr, u64 vbo, u64 pos,
+			 u8 *name, struct dir_context *ctx)
+{
+	int err;
+	const struct NTFS_DE *e;
+	u32 e_size;
+	u32 end = le32_to_cpu(hdr->used);
+	u32 off = le32_to_cpu(hdr->de_off);
+
+	for (;; off += e_size) {
+		if (off + sizeof(struct NTFS_DE) > end)
+			return -1;
+
+		e = Add2Ptr(hdr, off);
+		e_size = le16_to_cpu(e->size);
+		if (e_size < sizeof(struct NTFS_DE) || off + e_size > end)
+			return -1;
+
+		if (de_is_last(e))
+			return 0;
+
+		/* Skip already enumerated*/
+		if (vbo + off < pos)
+			continue;
+
+		if (le16_to_cpu(e->key_size) < SIZEOF_ATTRIBUTE_FILENAME)
+			return -1;
+
+		ctx->pos = vbo + off;
+
+		/* Submit the name to the filldir callback. */
+		err = ntfs_filldir(sbi, ni, e, name, ctx);
+		if (err)
+			return err;
+	}
+}
+
+/*
+ * file_operations::iterate_shared
+ *
+ * Use non sorted enumeration.
+ * We have an example of broken volume where sorted enumeration
+ * counts each name twice
+ */
+static int ntfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	const struct INDEX_ROOT *root;
+	u64 vbo;
+	size_t bit;
+	loff_t eod;
+	int err = 0;
+	struct inode *dir = file_inode(file);
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct super_block *sb = dir->i_sb;
+	struct ntfs_sb_info *sbi = sb->s_fs_info;
+	loff_t i_size = i_size_read(dir);
+	u32 pos = ctx->pos;
+	u8 *name = NULL;
+	struct indx_node *node = NULL;
+	u8 index_bits = ni->dir.index_bits;
+
+	/* name is a buffer of PATH_MAX length */
+	static_assert(NTFS_NAME_LEN * 4 < PATH_MAX);
+
+	eod = i_size + sbi->record_size;
+
+	if (pos >= eod)
+		return 0;
+
+	if (!dir_emit_dots(file, ctx))
+		return 0;
+
+	/* allocate PATH_MAX bytes */
+	name = __getname();
+	if (!name)
+		return -ENOMEM;
+
+	if (!ni->mi_loaded && ni->attr_list.size) {
+		/*
+		 * directory inode is locked for read
+		 * load all subrecords to avoid 'write' access to 'ni' during
+		 * directory reading
+		 */
+		ni_lock(ni);
+		if (!ni->mi_loaded && ni->attr_list.size) {
+			err = ni_load_all_mi(ni);
+			if (!err)
+				ni->mi_loaded = true;
+		}
+		ni_unlock(ni);
+		if (err)
+			goto out;
+	}
+
+	root = indx_get_root(&ni->dir, ni, NULL, NULL);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (pos >= sbi->record_size) {
+		bit = (pos - sbi->record_size) >> index_bits;
+	} else {
+		err = ntfs_read_hdr(sbi, ni, &root->ihdr, 0, pos, name, ctx);
+		if (err)
+			goto out;
+		bit = 0;
+	}
+
+	if (!i_size) {
+		ctx->pos = eod;
+		goto out;
+	}
+
+	for (;;) {
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size) {
+			ctx->pos = eod;
+			goto out;
+		}
+
+		err = indx_used_bit(&ni->dir, ni, &bit);
+		if (err)
+			goto out;
+
+		if (bit == MINUS_ONE_T) {
+			ctx->pos = eod;
+			goto out;
+		}
+
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size) {
+			ntfs_inode_err(dir, "Looks like your dir is corrupt");
+			err = -EINVAL;
+			goto out;
+		}
+
+		err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
+				&node);
+		if (err)
+			goto out;
+
+		err = ntfs_read_hdr(sbi, ni, &node->index->ihdr,
+				    vbo + sbi->record_size, pos, name, ctx);
+		if (err)
+			goto out;
+
+		bit += 1;
+	}
+
+out:
+
+	__putname(name);
+	put_indx_node(node);
+
+	if (err == -ENOENT) {
+		err = 0;
+		ctx->pos = pos;
+	}
+
+	return err;
+}
+
+static int ntfs_dir_count(struct inode *dir, bool *is_empty, size_t *dirs,
+			  size_t *files)
+{
+	int err = 0;
+	struct ntfs_inode *ni = ntfs_i(dir);
+	struct NTFS_DE *e = NULL;
+	struct INDEX_ROOT *root;
+	struct INDEX_HDR *hdr;
+	const struct ATTR_FILE_NAME *fname;
+	u32 e_size, off, end;
+	u64 vbo = 0;
+	size_t drs = 0, fles = 0, bit = 0;
+	loff_t i_size = ni->vfs_inode.i_size;
+	struct indx_node *node = NULL;
+	u8 index_bits = ni->dir.index_bits;
+
+	if (is_empty)
+		*is_empty = true;
+
+	root = indx_get_root(&ni->dir, ni, NULL, NULL);
+	if (!root)
+		return -EINVAL;
+
+	hdr = &root->ihdr;
+
+	for (;;) {
+		end = le32_to_cpu(hdr->used);
+		off = le32_to_cpu(hdr->de_off);
+
+		for (; off + sizeof(struct NTFS_DE) <= end; off += e_size) {
+			e = Add2Ptr(hdr, off);
+			e_size = le16_to_cpu(e->size);
+			if (e_size < sizeof(struct NTFS_DE) ||
+			    off + e_size > end)
+				break;
+
+			if (de_is_last(e))
+				break;
+
+			fname = de_get_fname(e);
+			if (!fname)
+				continue;
+
+			if (fname->type == FILE_NAME_DOS)
+				continue;
+
+			if (is_empty) {
+				*is_empty = false;
+				if (!dirs && !files)
+					goto out;
+			}
+
+			if (fname->dup.fa & FILE_ATTRIBUTE_DIRECTORY)
+				drs += 1;
+			else
+				fles += 1;
+		}
+
+		if (vbo >= i_size)
+			goto out;
+
+		err = indx_used_bit(&ni->dir, ni, &bit);
+		if (err)
+			goto out;
+
+		if (bit == MINUS_ONE_T)
+			goto out;
+
+		vbo = (u64)bit << index_bits;
+		if (vbo >= i_size)
+			goto out;
+
+		err = indx_read(&ni->dir, ni, bit << ni->dir.idx2vbn_bits,
+				&node);
+		if (err)
+			goto out;
+
+		hdr = &node->index->ihdr;
+		bit += 1;
+		vbo = (u64)bit << ni->dir.idx2vbn_bits;
+	}
+
+out:
+	put_indx_node(node);
+	if (dirs)
+		*dirs = drs;
+	if (files)
+		*files = fles;
+
+	return err;
+}
+
+bool dir_is_empty(struct inode *dir)
+{
+	bool is_empty = false;
+
+	ntfs_dir_count(dir, &is_empty, NULL, NULL);
+
+	return is_empty;
+}
+
+// clang-format off
+const struct file_operations ntfs_dir_operations = {
+	.llseek		= generic_file_llseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= ntfs_readdir,
+	.fsync		= generic_file_fsync,
+	.open		= ntfs_file_open,
+};
+// clang-format on
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;