Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 739 insertions, 0 deletions

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
new file mode 100644
index 000000000..e17bbc759
--- /dev/null
+++ b/fs/ext2/dir.c
@@ -0,0 +1,739 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/ext2/dir.c
+ *
+ * Copyright (C) 1992, 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ *
+ *  from
+ *
+ *  linux/fs/minix/dir.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  ext2 directory handling functions
+ *
+ *  Big-endian to little-endian byte-swapping/bitmaps by
+ *        David S. Miller (davem@caip.rutgers.edu), 1995
+ *
+ * All code that works with directory layout had been switched to pagecache
+ * and moved here. AV
+ */
+
+#include "ext2.h"
+#include <linux/buffer_head.h>
+#include <linux/filelock.h>
+#include <linux/pagemap.h>
+#include <linux/swap.h>
+#include <linux/iversion.h>
+
+typedef struct ext2_dir_entry_2 ext2_dirent;
+
+/*
+ * Tests against MAX_REC_LEN etc were put in place for 64k block
+ * sizes; if that is not possible on this arch, we can skip
+ * those tests and speed things up.
+ */
+static inline unsigned ext2_rec_len_from_disk(__le16 dlen)
+{
+	unsigned len = le16_to_cpu(dlen);
+
+#if (PAGE_SIZE >= 65536)
+	if (len == EXT2_MAX_REC_LEN)
+		return 1 << 16;
+#endif
+	return len;
+}
+
+static inline __le16 ext2_rec_len_to_disk(unsigned len)
+{
+#if (PAGE_SIZE >= 65536)
+	if (len == (1 << 16))
+		return cpu_to_le16(EXT2_MAX_REC_LEN);
+	else
+		BUG_ON(len > (1 << 16));
+#endif
+	return cpu_to_le16(len);
+}
+
+/*
+ * ext2 uses block-sized chunks. Arguably, sector-sized ones would be
+ * more robust, but we have what we have
+ */
+static inline unsigned ext2_chunk_size(struct inode *inode)
+{
+	return inode->i_sb->s_blocksize;
+}
+
+/*
+ * Return the offset into page `page_nr' of the last valid
+ * byte in that page, plus one.
+ */
+static unsigned
+ext2_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 void ext2_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 bool ext2_check_folio(struct folio *folio, int quiet, char *kaddr)
+{
+	struct inode *dir = folio->mapping->host;
+	struct super_block *sb = dir->i_sb;
+	unsigned chunk_size = ext2_chunk_size(dir);
+	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);
+	unsigned offs, rec_len;
+	unsigned limit = folio_size(folio);
+	ext2_dirent *p;
+	char *error;
+
+	if (dir->i_size < folio_pos(folio) + limit) {
+		limit = offset_in_folio(folio, dir->i_size);
+		if (limit & (chunk_size - 1))
+			goto Ebadsize;
+		if (!limit)
+			goto out;
+	}
+	for (offs = 0; offs <= limit - EXT2_DIR_REC_LEN(1); offs += rec_len) {
+		p = (ext2_dirent *)(kaddr + offs);
+		rec_len = ext2_rec_len_from_disk(p->rec_len);
+
+		if (unlikely(rec_len < EXT2_DIR_REC_LEN(1)))
+			goto Eshort;
+		if (unlikely(rec_len & 3))
+			goto Ealign;
+		if (unlikely(rec_len < EXT2_DIR_REC_LEN(p->name_len)))
+			goto Enamelen;
+		if (unlikely(((offs + rec_len - 1) ^ offs) & ~(chunk_size-1)))
+			goto Espan;
+		if (unlikely(le32_to_cpu(p->inode) > max_inumber))
+			goto Einumber;
+	}
+	if (offs != limit)
+		goto Eend;
+out:
+	folio_set_checked(folio);
+	return true;
+
+	/* Too bad, we had an error */
+
+Ebadsize:
+	if (!quiet)
+		ext2_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:
+	if (!quiet)
+		ext2_error(sb, __func__, "bad entry in directory #%llu: : %s - "
+			"offset=%llu, inode=%lu, rec_len=%d, name_len=%d",
+			dir->i_ino, error, folio_pos(folio) + offs,
+			(unsigned long) le32_to_cpu(p->inode),
+			rec_len, p->name_len);
+	goto fail;
+Eend:
+	if (!quiet) {
+		p = (ext2_dirent *)(kaddr + offs);
+		ext2_error(sb, "ext2_check_folio",
+			"entry in directory #%llu spans the page boundary"
+			"offset=%llu, inode=%lu",
+			dir->i_ino, folio_pos(folio) + offs,
+			(unsigned long) le32_to_cpu(p->inode));
+	}
+fail:
+	return false;
+}
+
+/*
+ * Calls to ext2_get_folio()/folio_release_kmap() must be nested according
+ * to the rules documented in kmap_local_folio()/kunmap_local().
+ *
+ * NOTE: ext2_find_entry() and ext2_dotdot() act as a call
+ * to folio_release_kmap() and should be treated as a call to
+ * folio_release_kmap() for nesting purposes.
+ */
+static void *ext2_get_folio(struct inode *dir, unsigned long n,
+				   int quiet, 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 (!ext2_check_folio(folio, quiet, kaddr))
+			goto fail;
+	}
+	*foliop = folio;
+	return kaddr;
+
+fail:
+	folio_release_kmap(folio, kaddr);
+	return ERR_PTR(-EIO);
+}
+
+/*
+ * NOTE! unlike strncmp, ext2_match returns 1 for success, 0 for failure.
+ *
+ * len <= EXT2_NAME_LEN and de != NULL are guaranteed by caller.
+ */
+static inline int ext2_match (int len, const char * const name,
+					struct ext2_dir_entry_2 * de)
+{
+	if (len != de->name_len)
+		return 0;
+	if (!de->inode)
+		return 0;
+	return !memcmp(name, de->name, len);
+}
+
+/*
+ * p is at least 6 bytes before the end of page
+ */
+static inline ext2_dirent *ext2_next_entry(ext2_dirent *p)
+{
+	return (ext2_dirent *)((char *)p +
+			ext2_rec_len_from_disk(p->rec_len));
+}
+
+static inline unsigned 
+ext2_validate_entry(char *base, unsigned offset, unsigned mask)
+{
+	ext2_dirent *de = (ext2_dirent*)(base + offset);
+	ext2_dirent *p = (ext2_dirent*)(base + (offset&mask));
+	while ((char*)p < (char*)de) {
+		if (p->rec_len == 0)
+			break;
+		p = ext2_next_entry(p);
+	}
+	return offset_in_page(p);
+}
+
+static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode)
+{
+	if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE))
+		de->file_type = fs_umode_to_ftype(inode->i_mode);
+	else
+		de->file_type = 0;
+}
+
+static int
+ext2_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 = ~(ext2_chunk_size(inode)-1);
+	bool need_revalidate = !inode_eq_iversion(inode, *(u64 *)file->private_data);
+	bool has_filetype;
+
+	if (pos > inode->i_size - EXT2_DIR_REC_LEN(1))
+		return 0;
+
+	has_filetype =
+		EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE);
+
+	for ( ; n < npages; n++, offset = 0) {
+		ext2_dirent *de;
+		struct folio *folio;
+		char *kaddr = ext2_get_folio(inode, n, 0, &folio);
+		char *limit;
+
+		if (IS_ERR(kaddr)) {
+			ext2_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 = ext2_validate_entry(kaddr, offset, chunk_mask);
+				ctx->pos = (n<<PAGE_SHIFT) + offset;
+			}
+			*(u64 *)file->private_data = inode_query_iversion(inode);
+			need_revalidate = false;
+		}
+		de = (ext2_dirent *)(kaddr+offset);
+		limit = kaddr + ext2_last_byte(inode, n) - EXT2_DIR_REC_LEN(1);
+		for ( ;(char*)de <= limit; de = ext2_next_entry(de)) {
+			if (de->rec_len == 0) {
+				ext2_error(sb, __func__,
+					"zero-length directory entry");
+				folio_release_kmap(folio, de);
+				return -EIO;
+			}
+			if (de->inode) {
+				unsigned char d_type = DT_UNKNOWN;
+
+				if (has_filetype)
+					d_type = fs_ftype_to_dtype(de->file_type);
+
+				if (!dir_emit(ctx, de->name, de->name_len,
+						le32_to_cpu(de->inode),
+						d_type)) {
+					folio_release_kmap(folio, de);
+					return 0;
+				}
+			}
+			ctx->pos += ext2_rec_len_from_disk(de->rec_len);
+		}
+		folio_release_kmap(folio, kaddr);
+	}
+	return 0;
+}
+
+/*
+ *	ext2_find_entry()
+ *
+ * finds an entry in the specified directory with the wanted name. It
+ * returns the page in which the entry was found (as a parameter - res_page),
+ * and the entry itself. Page is returned mapped and unlocked.
+ * Entry is guaranteed to be valid.
+ *
+ * On Success folio_release_kmap() should be called on *foliop.
+ *
+ * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested
+ * according to the rules documented in kmap_local_folio()/kunmap_local().
+ *
+ * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_folio()
+ * and should be treated as a call to ext2_get_folio() for nesting
+ * purposes.
+ */
+struct ext2_dir_entry_2 *ext2_find_entry (struct inode *dir,
+			const struct qstr *child, struct folio **foliop)
+{
+	const char *name = child->name;
+	int namelen = child->len;
+	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
+	unsigned long start, n;
+	unsigned long npages = dir_pages(dir);
+	struct ext2_inode_info *ei = EXT2_I(dir);
+	ext2_dirent * de;
+
+	if (npages == 0)
+		goto out;
+
+	start = ei->i_dir_start_lookup;
+	if (start >= npages)
+		start = 0;
+	n = start;
+	do {
+		char *kaddr = ext2_get_folio(dir, n, 0, foliop);
+		if (IS_ERR(kaddr))
+			return ERR_CAST(kaddr);
+
+		de = (ext2_dirent *) kaddr;
+		kaddr += ext2_last_byte(dir, n) - reclen;
+		while ((char *) de <= kaddr) {
+			if (de->rec_len == 0) {
+				ext2_error(dir->i_sb, __func__,
+					"zero-length directory entry");
+				folio_release_kmap(*foliop, de);
+				goto out;
+			}
+			if (ext2_match(namelen, name, de))
+				goto found;
+			de = ext2_next_entry(de);
+		}
+		folio_release_kmap(*foliop, kaddr);
+
+		if (++n >= npages)
+			n = 0;
+		/* next folio is past the blocks we've got */
+		if (unlikely(n > (dir->i_blocks >> (PAGE_SHIFT - 9)))) {
+			ext2_error(dir->i_sb, __func__,
+				"dir %llu size %lld exceeds block count %llu",
+				dir->i_ino, dir->i_size,
+				(unsigned long long)dir->i_blocks);
+			goto out;
+		}
+	} while (n != start);
+out:
+	return ERR_PTR(-ENOENT);
+
+found:
+	ei->i_dir_start_lookup = n;
+	return de;
+}
+
+/*
+ * Return the '..' directory entry and the page in which the entry was found
+ * (as a parameter - p).
+ *
+ * On Success folio_release_kmap() should be called on *foliop.
+ *
+ * NOTE: Calls to ext2_get_folio()/folio_release_kmap() must be nested
+ * according to the rules documented in kmap_local_folio()/kunmap_local().
+ *
+ * ext2_find_entry() and ext2_dotdot() act as a call to ext2_get_folio()
+ * and should be treated as a call to ext2_get_folio() for nesting
+ * purposes.
+ */
+struct ext2_dir_entry_2 *ext2_dotdot(struct inode *dir, struct folio **foliop)
+{
+	ext2_dirent *de = ext2_get_folio(dir, 0, 0, foliop);
+
+	if (!IS_ERR(de))
+		return ext2_next_entry(de);
+	return NULL;
+}
+
+int ext2_inode_by_name(struct inode *dir, const struct qstr *child, ino_t *ino)
+{
+	struct ext2_dir_entry_2 *de;
+	struct folio *folio;
+
+	de = ext2_find_entry(dir, child, &folio);
+	if (IS_ERR(de))
+		return PTR_ERR(de);
+
+	*ino = le32_to_cpu(de->inode);
+	folio_release_kmap(folio, de);
+	return 0;
+}
+
+static int ext2_prepare_chunk(struct folio *folio, loff_t pos, unsigned len)
+{
+	return __block_write_begin(folio, pos, len, ext2_get_block);
+}
+
+static int ext2_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;
+}
+
+int ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
+		struct folio *folio, struct inode *inode, bool update_times)
+{
+	loff_t pos = folio_pos(folio) + offset_in_folio(folio, de);
+	unsigned len = ext2_rec_len_from_disk(de->rec_len);
+	int err;
+
+	folio_lock(folio);
+	err = ext2_prepare_chunk(folio, pos, len);
+	if (err) {
+		folio_unlock(folio);
+		return err;
+	}
+	de->inode = cpu_to_le32(inode->i_ino);
+	ext2_set_de_type(de, inode);
+	ext2_commit_chunk(folio, pos, len);
+	if (update_times)
+		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
+	mark_inode_dirty(dir);
+	return ext2_handle_dirsync(dir);
+}
+
+/*
+ *	Parent is locked.
+ */
+int ext2_add_link (struct dentry *dentry, struct inode *inode)
+{
+	struct inode *dir = d_inode(dentry->d_parent);
+	const char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	unsigned chunk_size = ext2_chunk_size(dir);
+	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
+	unsigned short rec_len, name_len;
+	struct folio *folio = NULL;
+	ext2_dirent * de;
+	unsigned long npages = dir_pages(dir);
+	unsigned long n;
+	loff_t pos;
+	int err;
+
+	/*
+	 * 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 = ext2_get_folio(dir, n, 0, &folio);
+		char *dir_end;
+
+		if (IS_ERR(kaddr))
+			return PTR_ERR(kaddr);
+		folio_lock(folio);
+		dir_end = kaddr + ext2_last_byte(dir, n);
+		de = (ext2_dirent *)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->rec_len = ext2_rec_len_to_disk(chunk_size);
+				de->inode = 0;
+				goto got_it;
+			}
+			if (de->rec_len == 0) {
+				ext2_error(dir->i_sb, __func__,
+					"zero-length directory entry");
+				err = -EIO;
+				goto out_unlock;
+			}
+			err = -EEXIST;
+			if (ext2_match (namelen, name, de))
+				goto out_unlock;
+			name_len = EXT2_DIR_REC_LEN(de->name_len);
+			rec_len = ext2_rec_len_from_disk(de->rec_len);
+			if (!de->inode && rec_len >= reclen)
+				goto got_it;
+			if (rec_len >= name_len + reclen)
+				goto got_it;
+			de = (ext2_dirent *) ((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 = ext2_prepare_chunk(folio, pos, rec_len);
+	if (err)
+		goto out_unlock;
+	if (de->inode) {
+		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
+		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
+		de->rec_len = ext2_rec_len_to_disk(name_len);
+		de = de1;
+	}
+	de->name_len = namelen;
+	memcpy(de->name, name, namelen);
+	de->inode = cpu_to_le32(inode->i_ino);
+	ext2_set_de_type (de, inode);
+	ext2_commit_chunk(folio, pos, rec_len);
+	inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
+	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
+	mark_inode_dirty(dir);
+	err = ext2_handle_dirsync(dir);
+	/* OFFSET_CACHE */
+out_put:
+	folio_release_kmap(folio, de);
+	return err;
+out_unlock:
+	folio_unlock(folio);
+	goto out_put;
+}
+
+/*
+ * ext2_delete_entry deletes a directory entry by merging it with the
+ * previous entry. Page is up-to-date.
+ */
+int ext2_delete_entry(struct ext2_dir_entry_2 *dir, struct folio *folio)
+{
+	struct inode *inode = folio->mapping->host;
+	size_t from, to;
+	char *kaddr;
+	loff_t pos;
+	ext2_dirent *de, *pde = NULL;
+	int err;
+
+	from = offset_in_folio(folio, dir);
+	to = from + ext2_rec_len_from_disk(dir->rec_len);
+	kaddr = (char *)dir - from;
+	from &= ~(ext2_chunk_size(inode)-1);
+	de = (ext2_dirent *)(kaddr + from);
+
+	while ((char*)de < (char*)dir) {
+		if (de->rec_len == 0) {
+			ext2_error(inode->i_sb, __func__,
+				"zero-length directory entry");
+			return -EIO;
+		}
+		pde = de;
+		de = ext2_next_entry(de);
+	}
+	if (pde)
+		from = offset_in_folio(folio, pde);
+	pos = folio_pos(folio) + from;
+	folio_lock(folio);
+	err = ext2_prepare_chunk(folio, pos, to - from);
+	if (err) {
+		folio_unlock(folio);
+		return err;
+	}
+	if (pde)
+		pde->rec_len = ext2_rec_len_to_disk(to - from);
+	dir->inode = 0;
+	ext2_commit_chunk(folio, pos, to - from);
+	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+	EXT2_I(inode)->i_flags &= ~EXT2_BTREE_FL;
+	mark_inode_dirty(inode);
+	return ext2_handle_dirsync(inode);
+}
+
+/*
+ * Set the first fragment of directory.
+ */
+int ext2_make_empty(struct inode *inode, struct inode *parent)
+{
+	struct folio *folio = filemap_grab_folio(inode->i_mapping, 0);
+	unsigned chunk_size = ext2_chunk_size(inode);
+	struct ext2_dir_entry_2 * de;
+	int err;
+	void *kaddr;
+
+	if (IS_ERR(folio))
+		return PTR_ERR(folio);
+
+	err = ext2_prepare_chunk(folio, 0, chunk_size);
+	if (err) {
+		folio_unlock(folio);
+		goto fail;
+	}
+	kaddr = kmap_local_folio(folio, 0);
+	memset(kaddr, 0, chunk_size);
+	de = (struct ext2_dir_entry_2 *)kaddr;
+	de->name_len = 1;
+	de->rec_len = ext2_rec_len_to_disk(EXT2_DIR_REC_LEN(1));
+	memcpy (de->name, ".\0\0", 4);
+	de->inode = cpu_to_le32(inode->i_ino);
+	ext2_set_de_type (de, inode);
+
+	de = (struct ext2_dir_entry_2 *)(kaddr + EXT2_DIR_REC_LEN(1));
+	de->name_len = 2;
+	de->rec_len = ext2_rec_len_to_disk(chunk_size - EXT2_DIR_REC_LEN(1));
+	de->inode = cpu_to_le32(parent->i_ino);
+	memcpy (de->name, "..\0", 4);
+	ext2_set_de_type (de, inode);
+	kunmap_local(kaddr);
+	ext2_commit_chunk(folio, 0, chunk_size);
+	err = ext2_handle_dirsync(inode);
+fail:
+	folio_put(folio);
+	return err;
+}
+
+/*
+ * routine to check that the specified directory is empty (for rmdir)
+ */
+int ext2_empty_dir(struct inode *inode)
+{
+	struct folio *folio;
+	char *kaddr;
+	unsigned long i, npages = dir_pages(inode);
+
+	for (i = 0; i < npages; i++) {
+		ext2_dirent *de;
+
+		kaddr = ext2_get_folio(inode, i, 0, &folio);
+		if (IS_ERR(kaddr))
+			return 0;
+
+		de = (ext2_dirent *)kaddr;
+		kaddr += ext2_last_byte(inode, i) - EXT2_DIR_REC_LEN(1);
+
+		while ((char *)de <= kaddr) {
+			if (de->rec_len == 0) {
+				ext2_error(inode->i_sb, __func__,
+					"zero-length directory entry");
+				printk("kaddr=%p, de=%p\n", kaddr, de);
+				goto not_empty;
+			}
+			if (de->inode != 0) {
+				/* check for . and .. */
+				if (de->name[0] != '.')
+					goto not_empty;
+				if (de->name_len > 2)
+					goto not_empty;
+				if (de->name_len < 2) {
+					if (de->inode !=
+					    cpu_to_le32(inode->i_ino))
+						goto not_empty;
+				} else if (de->name[1] != '.')
+					goto not_empty;
+			}
+			de = ext2_next_entry(de);
+		}
+		folio_release_kmap(folio, kaddr);
+	}
+	return 1;
+
+not_empty:
+	folio_release_kmap(folio, kaddr);
+	return 0;
+}
+
+static int ext2_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 ext2_dir_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+static loff_t ext2_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 ext2_dir_operations = {
+	.open		= ext2_dir_open,
+	.release	= ext2_dir_release,
+	.llseek		= ext2_dir_llseek,
+	.read		= generic_read_dir,
+	.iterate_shared	= ext2_readdir,
+	.unlocked_ioctl = ext2_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl	= ext2_compat_ioctl,
+#endif
+	.fsync		= simple_fsync,
+	.setlease	= generic_setlease,
+};