kbuild: rust: keep Rust objects out of Clang LTO with inline helpersgrafted

Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit
`objtool` errors such as:

    vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a:
    can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd

The reason is that in such builds, the Clang invocation that compiles
the combined Rust plus helpers bitcode emits LLVM bitcode (again) --
the final code generation happens in the linker's LTO step, which the
`-mllvm` trap options passed to Clang do not reach.

This, in turn, means that unreachable traps are missing, and the
impossible paths do not merely fallthrough to the next symbol, but past
the end of their own section, since LTO builds place each function in
its own section.

Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always
emits machine code directly, with the traps in place.

Assisted-by: LLM
Cc: Gary Guo <gary@garyguo.net>
Cc: Boqun Feng <boqun@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matthew Maurer <mmaurer@google.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust")
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

1 files changed, 658 insertions, 0 deletions

diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
new file mode 100644
index 000000000..e62fe5667
--- /dev/null
+++ b/fs/ufs/dir.c
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ufs/ufs_dir.c
+ *
+ * Copyright (C) 1996
+ * Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
+ * Laboratory for Computer Science Research Computing Facility
+ * Rutgers, The State University of New Jersey
+ *
+ * swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
+ *
+ * 4.4BSD (FreeBSD) support added on February 1st 1998 by
+ * Niels Kristian Bech Jensen <nkbj@image.dk> partially based
+ * on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
+ *
+ * Migration to usage of "page cache" on May 2006 by
+ * Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/swap.h>
+#include <linux/iversion.h>
+
+#include "ufs_fs.h"
+#include "ufs.h"
+#include "swab.h"
+#include "util.h"
+
+/*
+ * NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
+ *
+ * len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
+ */
+static inline int ufs_match(struct super_block *sb, int len,
+		const unsigned char *name, struct ufs_dir_entry *de)
+{
+	if (len != ufs_get_de_namlen(sb, de))
+		return 0;
+	if (!de->d_ino)
+		return 0;
+	return !memcmp(name, de->d_name, len);
+}
+
+static void ufs_commit_chunk(struct folio *folio, loff_t pos, unsigned len)
+{
+	struct address_space *mapping = folio->mapping;
+	struct inode *dir = mapping->host;
+
+	inode_inc_iversion(dir);
+	block_write_end(pos, len, len, folio);
+	if (pos+len > dir->i_size) {
+		i_size_write(dir, pos+len);
+		mark_inode_dirty(dir);
+	}
+	folio_unlock(folio);
+}
+
+static int ufs_handle_dirsync(struct inode *dir)
+{
+	int err;
+
+	err = filemap_write_and_wait(dir->i_mapping);
+	if (!err)
+		err = sync_inode_metadata(dir, 1);
+	return err;
+}
+
+ino_t ufs_inode_by_name(struct inode *dir, const struct qstr *qstr)
+{
+	ino_t res = 0;
+	struct ufs_dir_entry *de;
+	struct folio *folio;
+	
+	de = ufs_find_entry(dir, qstr, &folio);
+	if (de) {
+		res = fs32_to_cpu(dir->i_sb, de->d_ino);
+		folio_release_kmap(folio, de);
+	}
+	return res;
+}
+
+
+int ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
+		 struct folio *folio, struct inode *inode,
+		 bool update_times)
+{
+	loff_t pos = folio_pos(folio) + offset_in_folio(folio, de);
+	unsigned len = fs16_to_cpu(dir->i_sb, de->d_reclen);
+	int err;
+
+	folio_lock(folio);
+	err = ufs_prepare_chunk(folio, pos, len);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		return err;
+	}
+
+	de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
+	ufs_set_de_type(dir->i_sb, de, inode->i_mode);
+
+	ufs_commit_chunk(folio, pos, len);
+	if (update_times)
+		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	mark_inode_dirty(dir);
+	return ufs_handle_dirsync(dir);
+}
+
+static bool ufs_check_folio(struct folio *folio, char *kaddr)
+{
+	struct inode *dir = folio->mapping->host;
+	struct super_block *sb = dir->i_sb;
+	unsigned offs, rec_len;
+	unsigned limit = folio_size(folio);
+	const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
+	struct ufs_dir_entry *p;
+	char *error;
+
+	if (dir->i_size < folio_pos(folio) + limit) {
+		limit = offset_in_folio(folio, dir->i_size);
+		if (limit & chunk_mask)
+			goto Ebadsize;
+		if (!limit)
+			goto out;
+	}
+	for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
+		p = (struct ufs_dir_entry *)(kaddr + offs);
+		rec_len = fs16_to_cpu(sb, p->d_reclen);
+
+		if (rec_len < UFS_DIR_REC_LEN(1))
+			goto Eshort;
+		if (rec_len & 3)
+			goto Ealign;
+		if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
+			goto Enamelen;
+		if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
+			goto Espan;
+		if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
+						  UFS_SB(sb)->s_uspi->s_ncg))
+			goto Einumber;
+	}
+	if (offs != limit)
+		goto Eend;
+out:
+	folio_set_checked(folio);
+	return true;
+
+	/* Too bad, we had an error */
+
+Ebadsize:
+	ufs_error(sb, __func__,
+		  "size of directory #%llu is not a multiple of chunk size",
+		  dir->i_ino
+	);
+	goto fail;
+Eshort:
+	error = "rec_len is smaller than minimal";
+	goto bad_entry;
+Ealign:
+	error = "unaligned directory entry";
+	goto bad_entry;
+Enamelen:
+	error = "rec_len is too small for name_len";
+	goto bad_entry;
+Espan:
+	error = "directory entry across blocks";
+	goto bad_entry;
+Einumber:
+	error = "inode out of bounds";
+bad_entry:
+	ufs_error(sb, __func__, "bad entry in directory #%llu: %s - "
+		   "offset=%llu, rec_len=%d, name_len=%d",
+		   dir->i_ino, error, folio_pos(folio) + offs,
+		   rec_len, ufs_get_de_namlen(sb, p));
+	goto fail;
+Eend:
+	p = (struct ufs_dir_entry *)(kaddr + offs);
+	ufs_error(sb, __func__,
+		   "entry in directory #%llu spans the page boundary"
+		   "offset=%llu",
+		   dir->i_ino, folio_pos(folio) + offs);
+fail:
+	return false;
+}
+
+static void *ufs_get_folio(struct inode *dir, unsigned long n,
+		struct folio **foliop)
+{
+	struct address_space *mapping = dir->i_mapping;
+	struct folio *folio = read_mapping_folio(mapping, n, NULL);
+	void *kaddr;
+
+	if (IS_ERR(folio))
+		return ERR_CAST(folio);
+	kaddr = kmap_local_folio(folio, 0);
+	if (unlikely(!folio_test_checked(folio))) {
+		if (!ufs_check_folio(folio, kaddr))
+			goto fail;
+	}
+	*foliop = folio;
+	return kaddr;
+
+fail:
+	folio_release_kmap(folio, kaddr);
+	return ERR_PTR(-EIO);
+}
+
+/*
+ * Return the offset into page `page_nr' of the last valid
+ * byte in that page, plus one.
+ */
+static unsigned
+ufs_last_byte(struct inode *inode, unsigned long page_nr)
+{
+	unsigned last_byte = inode->i_size;
+
+	last_byte -= page_nr << PAGE_SHIFT;
+	if (last_byte > PAGE_SIZE)
+		last_byte = PAGE_SIZE;
+	return last_byte;
+}
+
+static inline struct ufs_dir_entry *
+ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
+{
+	return (struct ufs_dir_entry *)((char *)p +
+					fs16_to_cpu(sb, p->d_reclen));
+}
+
+struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct folio **foliop)
+{
+	struct ufs_dir_entry *de = ufs_get_folio(dir, 0, foliop);
+
+	if (!IS_ERR(de))
+		return ufs_next_entry(dir->i_sb, de);
+
+	return NULL;
+}
+
+/*
+ *	ufs_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the page in which the entry was found, and the entry itself
+ * (as a parameter - res_dir). Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ */
+struct ufs_dir_entry *ufs_find_entry(struct inode *dir, const struct qstr *qstr,
+				     struct folio **foliop)
+{
+	struct super_block *sb = dir->i_sb;
+	const unsigned char *name = qstr->name;
+	int namelen = qstr->len;
+	unsigned reclen = UFS_DIR_REC_LEN(namelen);
+	unsigned long start, n;
+	unsigned long npages = dir_pages(dir);
+	struct ufs_inode_info *ui = UFS_I(dir);
+	struct ufs_dir_entry *de;
+
+	UFSD("ENTER, dir_ino %llu, name %s, namlen %u\n", dir->i_ino, name, namelen);
+
+	if (npages == 0 || namelen > UFS_MAXNAMLEN)
+		goto out;
+
+	start = ui->i_dir_start_lookup;
+
+	if (start >= npages)
+		start = 0;
+	n = start;
+	do {
+		char *kaddr = ufs_get_folio(dir, n, foliop);
+
+		if (!IS_ERR(kaddr)) {
+			de = (struct ufs_dir_entry *)kaddr;
+			kaddr += ufs_last_byte(dir, n) - reclen;
+			while ((char *) de <= kaddr) {
+				if (ufs_match(sb, namelen, name, de))
+					goto found;
+				de = ufs_next_entry(sb, de);
+			}
+			folio_release_kmap(*foliop, kaddr);
+		}
+		if (++n >= npages)
+			n = 0;
+	} while (n != start);
+out:
+	return NULL;
+
+found:
+	ui->i_dir_start_lookup = n;
+	return de;
+}
+
+/*
+ *	Parent is locked.
+ */
+int ufs_add_link(struct dentry *dentry, struct inode *inode)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	const unsigned char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	struct super_block *sb = dir->i_sb;
+	unsigned reclen = UFS_DIR_REC_LEN(namelen);
+	const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
+	unsigned short rec_len, name_len;
+	struct folio *folio = NULL;
+	struct ufs_dir_entry *de;
+	unsigned long npages = dir_pages(dir);
+	unsigned long n;
+	loff_t pos;
+	int err;
+
+	UFSD("ENTER, name %s, namelen %u\n", name, namelen);
+
+	/*
+	 * We take care of directory expansion in the same loop.
+	 * This code plays outside i_size, so it locks the folio
+	 * to protect that region.
+	 */
+	for (n = 0; n <= npages; n++) {
+		char *kaddr = ufs_get_folio(dir, n, &folio);
+		char *dir_end;
+
+		if (IS_ERR(kaddr))
+			return PTR_ERR(kaddr);
+		folio_lock(folio);
+		dir_end = kaddr + ufs_last_byte(dir, n);
+		de = (struct ufs_dir_entry *)kaddr;
+		kaddr += folio_size(folio) - reclen;
+		while ((char *)de <= kaddr) {
+			if ((char *)de == dir_end) {
+				/* We hit i_size */
+				name_len = 0;
+				rec_len = chunk_size;
+				de->d_reclen = cpu_to_fs16(sb, chunk_size);
+				de->d_ino = 0;
+				goto got_it;
+			}
+			if (de->d_reclen == 0) {
+				ufs_error(dir->i_sb, __func__,
+					  "zero-length directory entry");
+				err = -EIO;
+				goto out_unlock;
+			}
+			err = -EEXIST;
+			if (ufs_match(sb, namelen, name, de))
+				goto out_unlock;
+			name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
+			rec_len = fs16_to_cpu(sb, de->d_reclen);
+			if (!de->d_ino && rec_len >= reclen)
+				goto got_it;
+			if (rec_len >= name_len + reclen)
+				goto got_it;
+			de = (struct ufs_dir_entry *) ((char *) de + rec_len);
+		}
+		folio_unlock(folio);
+		folio_release_kmap(folio, kaddr);
+	}
+	BUG();
+	return -EINVAL;
+
+got_it:
+	pos = folio_pos(folio) + offset_in_folio(folio, de);
+	err = ufs_prepare_chunk(folio, pos, rec_len);
+	if (err)
+		goto out_unlock;
+	if (de->d_ino) {
+		struct ufs_dir_entry *de1 =
+			(struct ufs_dir_entry *) ((char *) de + name_len);
+		de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
+		de->d_reclen = cpu_to_fs16(sb, name_len);
+
+		de = de1;
+	}
+
+	ufs_set_de_namlen(sb, de, namelen);
+	memcpy(de->d_name, name, namelen + 1);
+	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
+	ufs_set_de_type(sb, de, inode->i_mode);
+
+	ufs_commit_chunk(folio, pos, rec_len);
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+
+	mark_inode_dirty(dir);
+	err = ufs_handle_dirsync(dir);
+	/* OFFSET_CACHE */
+out_put:
+	folio_release_kmap(folio, de);
+	return err;
+out_unlock:
+	folio_unlock(folio);
+	goto out_put;
+}
+
+static inline unsigned
+ufs_validate_entry(struct super_block *sb, char *base,
+		   unsigned offset, unsigned mask)
+{
+	struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
+	struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
+	while ((char*)p < (char*)de)
+		p = ufs_next_entry(sb, p);
+	return (char *)p - base;
+}
+
+
+/*
+ * This is blatantly stolen from ext2fs
+ */
+static int
+ufs_readdir(struct file *file, struct dir_context *ctx)
+{
+	loff_t pos = ctx->pos;
+	struct inode *inode = file_inode(file);
+	struct super_block *sb = inode->i_sb;
+	unsigned int offset = pos & ~PAGE_MASK;
+	unsigned long n = pos >> PAGE_SHIFT;
+	unsigned long npages = dir_pages(inode);
+	unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
+	bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data);
+	unsigned flags = UFS_SB(sb)->s_flags;
+
+	UFSD("BEGIN\n");
+
+	if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
+		return 0;
+
+	for ( ; n < npages; n++, offset = 0) {
+		struct ufs_dir_entry *de;
+		struct folio *folio;
+		char *kaddr = ufs_get_folio(inode, n, &folio);
+		char *limit;
+
+		if (IS_ERR(kaddr)) {
+			ufs_error(sb, __func__,
+				  "bad page in #%llu",
+				  inode->i_ino);
+			ctx->pos += PAGE_SIZE - offset;
+			return PTR_ERR(kaddr);
+		}
+		if (unlikely(need_revalidate)) {
+			if (offset) {
+				offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
+				ctx->pos = (n<<PAGE_SHIFT) + offset;
+			}
+			*(u64 *)file->private_data = inode_query_iversion(inode);
+			need_revalidate = false;
+		}
+		de = (struct ufs_dir_entry *)(kaddr+offset);
+		limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
+		for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
+			if (de->d_ino) {
+				unsigned char d_type = DT_UNKNOWN;
+
+				UFSD("filldir(%s,%u)\n", de->d_name,
+				      fs32_to_cpu(sb, de->d_ino));
+				UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
+
+				if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
+					d_type = de->d_u.d_44.d_type;
+
+				if (!dir_emit(ctx, de->d_name,
+					       ufs_get_de_namlen(sb, de),
+					       fs32_to_cpu(sb, de->d_ino),
+					       d_type)) {
+					folio_release_kmap(folio, de);
+					return 0;
+				}
+			}
+			ctx->pos += fs16_to_cpu(sb, de->d_reclen);
+		}
+		folio_release_kmap(folio, kaddr);
+	}
+	return 0;
+}
+
+
+/*
+ * ufs_delete_entry deletes a directory entry by merging it with the
+ * previous entry.
+ */
+int ufs_delete_entry(struct inode *inode, struct ufs_dir_entry *dir,
+		     struct folio *folio)
+{
+	struct super_block *sb = inode->i_sb;
+	size_t from, to;
+	char *kaddr;
+	loff_t pos;
+	struct ufs_dir_entry *de, *pde = NULL;
+	int err;
+
+	UFSD("ENTER\n");
+
+	from = offset_in_folio(folio, dir);
+	to = from + fs16_to_cpu(sb, dir->d_reclen);
+	kaddr = (char *)dir - from;
+	from &= ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
+	de = (struct ufs_dir_entry *) (kaddr + from);
+
+	UFSD("ino %u, reclen %u, namlen %u, name %s\n",
+	      fs32_to_cpu(sb, de->d_ino),
+	      fs16_to_cpu(sb, de->d_reclen),
+	      ufs_get_de_namlen(sb, de), de->d_name);
+
+	while ((char*)de < (char*)dir) {
+		if (de->d_reclen == 0) {
+			ufs_error(inode->i_sb, __func__,
+				  "zero-length directory entry");
+			return -EIO;
+		}
+		pde = de;
+		de = ufs_next_entry(sb, de);
+	}
+	if (pde)
+		from = offset_in_folio(folio, pde);
+	pos = folio_pos(folio) + from;
+	folio_lock(folio);
+	err = ufs_prepare_chunk(folio, pos, to - from);
+	if (unlikely(err)) {
+		folio_unlock(folio);
+		return err;
+	}
+	if (pde)
+		pde->d_reclen = cpu_to_fs16(sb, to - from);
+	dir->d_ino = 0;
+	ufs_commit_chunk(folio, pos, to - from);
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	mark_inode_dirty(inode);
+	return ufs_handle_dirsync(inode);
+}
+
+int ufs_make_empty(struct inode * inode, struct inode *dir)
+{
+	struct super_block * sb = dir->i_sb;
+	struct address_space *mapping = inode->i_mapping;
+	struct folio *folio = filemap_grab_folio(mapping, 0);
+	const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
+	struct ufs_dir_entry * de;
+	int err;
+	char *kaddr;
+
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
+
+	err = ufs_prepare_chunk(folio, 0, chunk_size);
+	if (err) {
+		folio_unlock(folio);
+		goto fail;
+	}
+
+	kaddr = kmap_local_folio(folio, 0);
+	memset(kaddr, 0, folio_size(folio));
+
+	de = (struct ufs_dir_entry *)kaddr;
+
+	de->d_ino = cpu_to_fs32(sb, inode->i_ino);
+	ufs_set_de_type(sb, de, inode->i_mode);
+	ufs_set_de_namlen(sb, de, 1);
+	de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
+	strcpy (de->d_name, ".");
+	de = (struct ufs_dir_entry *)
+		((char *)de + fs16_to_cpu(sb, de->d_reclen));
+	de->d_ino = cpu_to_fs32(sb, dir->i_ino);
+	ufs_set_de_type(sb, de, dir->i_mode);
+	de->d_reclen = cpu_to_fs16(sb, chunk_size - UFS_DIR_REC_LEN(1));
+	ufs_set_de_namlen(sb, de, 2);
+	strcpy (de->d_name, "..");
+	kunmap_local(kaddr);
+
+	ufs_commit_chunk(folio, 0, chunk_size);
+	err = ufs_handle_dirsync(inode);
+fail:
+	folio_put(folio);
+	return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+int ufs_empty_dir(struct inode * inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct folio *folio;
+	char *kaddr;
+	unsigned long i, npages = dir_pages(inode);
+
+	for (i = 0; i < npages; i++) {
+		struct ufs_dir_entry *de;
+
+		kaddr = ufs_get_folio(inode, i, &folio);
+		if (IS_ERR(kaddr))
+			continue;
+
+		de = (struct ufs_dir_entry *)kaddr;
+		kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
+
+		while ((char *)de <= kaddr) {
+			if (de->d_reclen == 0) {
+				ufs_error(inode->i_sb, __func__,
+					"zero-length directory entry: "
+					"kaddr=%p, de=%p\n", kaddr, de);
+				goto not_empty;
+			}
+			if (de->d_ino) {
+				u16 namelen=ufs_get_de_namlen(sb, de);
+				/* check for . and .. */
+				if (de->d_name[0] != '.')
+					goto not_empty;
+				if (namelen > 2)
+					goto not_empty;
+				if (namelen < 2) {
+					if (inode->i_ino !=
+					    fs32_to_cpu(sb, de->d_ino))
+						goto not_empty;
+				} else if (de->d_name[1] != '.')
+					goto not_empty;
+			}
+			de = ufs_next_entry(sb, de);
+		}
+		folio_release_kmap(folio, kaddr);
+	}
+	return 1;
+
+not_empty:
+	folio_release_kmap(folio, kaddr);
+	return 0;
+}
+
+static int ufs_dir_open(struct inode *inode, struct file *file)
+{
+	file->private_data = kzalloc(sizeof(u64), GFP_KERNEL);
+	if (!file->private_data)
+		return -ENOMEM;
+	return 0;
+}
+
+static int ufs_dir_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static loff_t ufs_dir_llseek(struct file *file, loff_t offset, int whence)
+{
+	return generic_llseek_cookie(file, offset, whence,
+				     (u64 *)file->private_data);
+}
+
+const struct file_operations ufs_dir_operations = {
+	.open		= ufs_dir_open,
+	.release	= ufs_dir_release,
+	.read		= generic_read_dir,
+	.iterate_shared	= ufs_readdir,
+	.fsync		= simple_fsync,
+	.llseek		= ufs_dir_llseek,
+	.setlease	= generic_setlease,
+};