selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 706 insertions, 0 deletions

diff --git a/fs/exfat/exfat_fs.h b/fs/exfat/exfat_fs.h
new file mode 100644
index 000000000..9be50949c
--- /dev/null
+++ b/fs/exfat/exfat_fs.h
@@ -0,0 +1,706 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef _EXFAT_FS_H
+#define _EXFAT_FS_H
+
+#include <linux/fs.h>
+#include <linux/ratelimit.h>
+#include <linux/nls.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <uapi/linux/exfat.h>
+#include <linux/buffer_head.h>
+
+#define EXFAT_ROOT_INO		1
+
+/*
+ * exfat error flags
+ */
+enum exfat_error_mode {
+	EXFAT_ERRORS_CONT,	/* ignore error and continue */
+	EXFAT_ERRORS_PANIC,	/* panic on error */
+	EXFAT_ERRORS_RO,	/* remount r/o on error */
+};
+
+/*
+ * exfat nls lossy flag
+ */
+enum {
+	NLS_NAME_NO_LOSSY =	0,	/* no lossy */
+	NLS_NAME_LOSSY =	1 << 0,	/* just detected incorrect filename(s) */
+};
+
+#define EXFAT_HASH_BITS		8
+#define EXFAT_HASH_SIZE		(1UL << EXFAT_HASH_BITS)
+
+/*
+ * Type Definitions
+ */
+#define ES_2_ENTRIES		2
+#define ES_ALL_ENTRIES		0
+
+#define ES_IDX_FILE		0
+#define ES_IDX_STREAM		1
+#define ES_IDX_FIRST_FILENAME	2
+#define EXFAT_FILENAME_ENTRY_NUM(name_len) \
+	DIV_ROUND_UP(name_len, EXFAT_FILE_NAME_LEN)
+#define ES_IDX_LAST_FILENAME(name_len)	\
+	(ES_IDX_FIRST_FILENAME + EXFAT_FILENAME_ENTRY_NUM(name_len) - 1)
+
+#define DIR_DELETED		0xFFFFFFF7
+
+/* type values */
+#define TYPE_UNUSED		0x0000
+#define TYPE_DELETED		0x0001
+#define TYPE_INVALID		0x0002
+#define TYPE_CRITICAL_PRI	0x0100
+#define TYPE_BITMAP		0x0101
+#define TYPE_UPCASE		0x0102
+#define TYPE_VOLUME		0x0103
+#define TYPE_DIR		0x0104
+#define TYPE_FILE		0x011F
+#define TYPE_CRITICAL_SEC	0x0200
+#define TYPE_STREAM		0x0201
+#define TYPE_EXTEND		0x0202
+#define TYPE_ACL		0x0203
+#define TYPE_BENIGN_PRI		0x0400
+#define TYPE_GUID		0x0401
+#define TYPE_PADDING		0x0402
+#define TYPE_ACLTAB		0x0403
+#define TYPE_BENIGN_SEC		0x0800
+#define TYPE_VENDOR_EXT		0x0801
+#define TYPE_VENDOR_ALLOC	0x0802
+
+#define MAX_CHARSET_SIZE	6 /* max size of multi-byte character */
+#define MAX_NAME_LENGTH		255 /* max len of file name excluding NULL */
+#define MAX_VFSNAME_BUF_SIZE	((MAX_NAME_LENGTH + 1) * MAX_CHARSET_SIZE)
+
+#define EXFAT_HINT_NONE		-1
+#define EXFAT_MIN_SUBDIR	2
+
+#define EXFAT_BLK_RA_SIZE(sb)		\
+	(min_t(blkcnt_t, (sb)->s_bdi->ra_pages, (sb)->s_bdi->io_pages) \
+	<< (PAGE_SHIFT - (sb)->s_blocksize_bits))
+
+/*
+ * helpers for fat entry.
+ */
+#define FAT_ENT_SIZE (4)
+#define FAT_ENT_SIZE_BITS (2)
+#define FAT_ENT_OFFSET_SECTOR(sb, loc) (EXFAT_SB(sb)->FAT1_start_sector + \
+	(((u64)(loc) << FAT_ENT_SIZE_BITS) >> sb->s_blocksize_bits))
+#define FAT_ENT_OFFSET_BYTE_IN_SECTOR(sb, loc)	\
+	(((loc) << FAT_ENT_SIZE_BITS) & (sb->s_blocksize - 1))
+
+/*
+ * helpers for bitmap.
+ */
+#define CLUSTER_TO_BITMAP_ENT(clu) ((clu) - EXFAT_RESERVED_CLUSTERS)
+#define BITMAP_ENT_TO_CLUSTER(ent) ((ent) + EXFAT_RESERVED_CLUSTERS)
+#define BITS_PER_SECTOR(sb) ((sb)->s_blocksize * BITS_PER_BYTE)
+#define BITS_PER_SECTOR_MASK(sb) (BITS_PER_SECTOR(sb) - 1)
+#define BITMAP_OFFSET_SECTOR_INDEX(sb, ent) \
+	((ent / BITS_PER_BYTE) >> (sb)->s_blocksize_bits)
+#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
+#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
+	((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
+#define IGNORED_BITS_REMAINED(clu, clu_base) ((1UL << ((clu) - (clu_base))) - 1)
+
+#define ES_ENTRY_NUM(name_len)	(ES_IDX_LAST_FILENAME(name_len) + 1)
+/* 19 entries = 1 file entry + 1 stream entry + 17 filename entries */
+#define ES_MAX_ENTRY_NUM	ES_ENTRY_NUM(MAX_NAME_LENGTH)
+
+/*
+ * 19 entries x 32 bytes/entry = 608 bytes.
+ * The 608 bytes are in 3 sectors at most (even 512 Byte sector).
+ */
+#define DIR_CACHE_SIZE		\
+	(DIV_ROUND_UP(ES_MAX_ENTRY_NUM << DENTRY_SIZE_BITS, SECTOR_SIZE) + 1)
+
+/* Superblock flags */
+#define EXFAT_FLAGS_SHUTDOWN	1
+
+struct exfat_dentry_namebuf {
+	char *lfn;
+	int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */
+};
+
+/* unicode name structure */
+struct exfat_uni_name {
+	/* +3 for null and for converting */
+	unsigned short name[MAX_NAME_LENGTH + 3];
+	u16 name_hash;
+	unsigned char name_len;
+};
+
+/* directory structure */
+struct exfat_chain {
+	unsigned int dir;
+	unsigned int size;
+	unsigned char flags;
+};
+
+/* first empty entry hint information */
+struct exfat_hint_femp {
+	/* entry index of a directory */
+	int eidx;
+	/* count of continuous empty entry */
+	int count;
+	/* the cluster that first empty slot exists in */
+	struct exfat_chain cur;
+};
+
+/* hint structure */
+struct exfat_hint {
+	unsigned int clu;
+	union {
+		unsigned int off; /* cluster offset */
+		int eidx; /* entry index */
+	};
+};
+
+struct exfat_entry_set_cache {
+	struct super_block *sb;
+	unsigned int start_off;
+	int num_bh;
+	struct buffer_head *__bh[DIR_CACHE_SIZE];
+	struct buffer_head **bh;
+	unsigned int num_entries;
+	bool modified;
+};
+
+#define IS_DYNAMIC_ES(es)	((es)->__bh != (es)->bh)
+
+struct exfat_dir_entry {
+	/* the cluster where file dentry is located */
+	struct exfat_chain dir;
+	/* the index of file dentry in ->dir */
+	int entry;
+	unsigned int type;
+	unsigned int start_clu;
+	unsigned char flags;
+	unsigned short attr;
+	loff_t size;
+	loff_t valid_size;
+	unsigned int num_subdirs;
+	struct timespec64 atime;
+	struct timespec64 mtime;
+	struct timespec64 crtime;
+	struct exfat_dentry_namebuf namebuf;
+};
+
+/*
+ * exfat mount in-memory data
+ */
+struct exfat_mount_options {
+	kuid_t fs_uid;
+	kgid_t fs_gid;
+	unsigned short fs_fmask;
+	unsigned short fs_dmask;
+	/* permission for setting the [am]time */
+	unsigned short allow_utime;
+	/* charset for filename input/display */
+	char *iocharset;
+	/* on error: continue, panic, remount-ro */
+	enum exfat_error_mode errors;
+	unsigned utf8:1, /* Use of UTF-8 character set */
+		 sys_tz:1, /* Use local timezone */
+		 discard:1, /* Issue discard requests on deletions */
+		 keep_last_dots:1; /* Keep trailing periods in paths */
+	int time_offset; /* Offset of timestamps from UTC (in minutes) */
+	/* Support creating zero-size directory, default: false */
+	bool zero_size_dir;
+};
+
+/*
+ * EXFAT file system superblock in-memory data
+ */
+struct exfat_sb_info {
+	unsigned long long num_sectors; /* num of sectors in volume */
+	unsigned int num_clusters; /* num of clusters in volume */
+	unsigned int cluster_size; /* cluster size in bytes */
+	unsigned int cluster_size_bits;
+	unsigned int sect_per_clus; /* cluster size in sectors */
+	unsigned int sect_per_clus_bits;
+	unsigned long long FAT1_start_sector; /* FAT1 start sector */
+	unsigned long long FAT2_start_sector; /* FAT2 start sector */
+	unsigned long long data_start_sector; /* data area start sector */
+	unsigned long long data_start_bytes;
+	unsigned int num_FAT_sectors; /* num of FAT sectors */
+	unsigned int root_dir; /* root dir cluster */
+	unsigned int dentries_per_clu; /* num of dentries per cluster */
+	unsigned int vol_flags; /* volume flags */
+	unsigned int vol_flags_persistent; /* volume flags to retain */
+	struct buffer_head *boot_bh; /* buffer_head of BOOT sector */
+
+	unsigned int map_clu; /* allocation bitmap start cluster */
+	unsigned int map_sectors; /* num of allocation bitmap sectors */
+	struct buffer_head **vol_amap; /* allocation bitmap */
+
+	unsigned short *vol_utbl; /* upcase table */
+
+	unsigned int clu_srch_ptr; /* cluster search pointer */
+	unsigned int used_clusters; /* number of used clusters */
+
+	unsigned long s_exfat_flags; /* Exfat superblock flags */
+
+	struct mutex s_lock; /* superblock lock */
+	struct mutex bitmap_lock; /* bitmap lock */
+	struct exfat_mount_options options;
+	struct nls_table *nls_io; /* Charset used for input and display */
+	struct ratelimit_state ratelimit;
+
+	spinlock_t inode_hash_lock;
+	struct hlist_head inode_hashtable[EXFAT_HASH_SIZE];
+	struct rcu_head rcu;
+};
+
+#define EXFAT_CACHE_VALID	0
+
+/*
+ * EXFAT file system inode in-memory data
+ */
+struct exfat_inode_info {
+	/* the cluster where file dentry is located */
+	struct exfat_chain dir;
+	/* the index of file dentry in ->dir */
+	int entry;
+	unsigned int type;
+	unsigned short attr;
+	unsigned int start_clu;
+	unsigned char flags;
+	/*
+	 * the copy of low 32bit of i_version to check
+	 * the validation of hint_stat.
+	 */
+	unsigned int version;
+
+	/* hint for cluster last accessed */
+	struct exfat_hint hint_bmap;
+	/* hint for entry index we try to lookup next time */
+	struct exfat_hint hint_stat;
+	/* hint for first empty entry */
+	struct exfat_hint_femp hint_femp;
+
+	spinlock_t cache_lru_lock;
+	struct list_head cache_lru;
+	int nr_caches;
+	/* for avoiding the race between alloc and free */
+	unsigned int cache_valid_id;
+
+	/* on-disk position of directory entry or 0 */
+	loff_t i_pos;
+	loff_t valid_size;
+	/* page-aligned size that has been zeroed out for mmap */
+	loff_t zeroed_size;
+	/* hash by i_location */
+	struct hlist_node i_hash_fat;
+	/* protect bmap against truncate */
+	struct rw_semaphore truncate_lock;
+	struct inode vfs_inode;
+	/* File creation time */
+	struct timespec64 i_crtime;
+};
+
+static inline struct exfat_sb_info *EXFAT_SB(struct super_block *sb)
+{
+	return sb->s_fs_info;
+}
+
+static inline struct exfat_inode_info *EXFAT_I(struct inode *inode)
+{
+	return container_of(inode, struct exfat_inode_info, vfs_inode);
+}
+
+static inline int exfat_forced_shutdown(struct super_block *sb)
+{
+	return test_bit(EXFAT_FLAGS_SHUTDOWN, &EXFAT_SB(sb)->s_exfat_flags);
+}
+
+/*
+ * If ->i_mode can't hold 0222 (i.e. ATTR_RO), we use ->i_attrs to
+ * save ATTR_RO instead of ->i_mode.
+ *
+ * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only
+ * bit, it's just used as flag for app.
+ */
+static inline int exfat_mode_can_hold_ro(struct inode *inode)
+{
+	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
+
+	if (S_ISDIR(inode->i_mode))
+		return 0;
+
+	if ((~sbi->options.fs_fmask) & 0222)
+		return 1;
+	return 0;
+}
+
+/* Convert attribute bits and a mask to the UNIX mode. */
+static inline mode_t exfat_make_mode(struct exfat_sb_info *sbi,
+		unsigned short attr, mode_t mode)
+{
+	if ((attr & EXFAT_ATTR_READONLY) && !(attr & EXFAT_ATTR_SUBDIR))
+		mode &= ~0222;
+
+	if (attr & EXFAT_ATTR_SUBDIR)
+		return (mode & ~sbi->options.fs_dmask) | S_IFDIR;
+
+	return (mode & ~sbi->options.fs_fmask) | S_IFREG;
+}
+
+/* Return the FAT attribute byte for this inode */
+static inline unsigned short exfat_make_attr(struct inode *inode)
+{
+	unsigned short attr = EXFAT_I(inode)->attr;
+
+	if (S_ISDIR(inode->i_mode))
+		attr |= EXFAT_ATTR_SUBDIR;
+	if (exfat_mode_can_hold_ro(inode) && !(inode->i_mode & 0222))
+		attr |= EXFAT_ATTR_READONLY;
+	return attr;
+}
+
+static inline void exfat_save_attr(struct inode *inode, unsigned short attr)
+{
+	if (exfat_mode_can_hold_ro(inode))
+		EXFAT_I(inode)->attr = attr & (EXFAT_ATTR_RWMASK | EXFAT_ATTR_READONLY);
+	else
+		EXFAT_I(inode)->attr = attr & EXFAT_ATTR_RWMASK;
+}
+
+static inline bool exfat_is_last_sector_in_cluster(struct exfat_sb_info *sbi,
+		sector_t sec)
+{
+	return ((sec - sbi->data_start_sector + 1) &
+		((1 << sbi->sect_per_clus_bits) - 1)) == 0;
+}
+
+static inline sector_t exfat_cluster_to_sector(struct exfat_sb_info *sbi,
+		unsigned int clus)
+{
+	return ((sector_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->sect_per_clus_bits) +
+		sbi->data_start_sector;
+}
+
+static inline unsigned int exfat_sector_to_cluster(struct exfat_sb_info *sbi,
+		sector_t sec)
+{
+	return ((sec - sbi->data_start_sector) >> sbi->sect_per_clus_bits) +
+		EXFAT_RESERVED_CLUSTERS;
+}
+
+static inline bool is_valid_cluster(struct exfat_sb_info *sbi,
+		unsigned int clus)
+{
+	return clus >= EXFAT_FIRST_CLUSTER && clus < sbi->num_clusters;
+}
+
+static inline loff_t exfat_ondisk_size(const struct inode *inode)
+{
+	return ((loff_t)inode->i_blocks) << 9;
+}
+
+static inline loff_t exfat_cluster_to_phys_bytes(struct exfat_sb_info *sbi,
+		unsigned int clus)
+{
+	return ((loff_t)(clus - EXFAT_RESERVED_CLUSTERS) << sbi->cluster_size_bits) +
+		sbi->data_start_bytes;
+}
+
+/*
+ * helpers for cluster size to byte conversion.
+ */
+static inline loff_t exfat_cluster_to_bytes(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return (loff_t)nr_clusters << sbi->cluster_size_bits;
+}
+
+static inline blkcnt_t exfat_cluster_to_sectors(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return (blkcnt_t)nr_clusters << (sbi->cluster_size_bits - 9);
+}
+
+static inline u32 exfat_bytes_to_cluster(struct exfat_sb_info *sbi, loff_t size)
+{
+	return (u32)(size >> sbi->cluster_size_bits);
+}
+
+static inline u32 exfat_bytes_to_cluster_round_up(struct exfat_sb_info *sbi,
+		loff_t size)
+{
+	if (size <= 0)
+		return 0;
+	return (u32)((size - 1) >> sbi->cluster_size_bits) + 1;
+}
+
+static inline u32 exfat_cluster_offset(struct exfat_sb_info *sbi, loff_t off)
+{
+	return off & (sbi->cluster_size - 1);
+}
+
+/*
+ * helpers for block size to byte conversion.
+ */
+static inline loff_t exfat_block_to_bytes(struct super_block *sb,
+		sector_t block)
+{
+	return (loff_t)block << sb->s_blocksize_bits;
+}
+
+static inline sector_t exfat_bytes_to_block(struct super_block *sb, loff_t size)
+{
+	return (sector_t)(size >> sb->s_blocksize_bits);
+}
+
+static inline sector_t exfat_bytes_to_block_round_up(struct super_block *sb,
+		loff_t size)
+{
+	if (size <= 0)
+		return 0;
+	return (sector_t)(((size - 1) >> sb->s_blocksize_bits) + 1);
+}
+
+static inline u32 exfat_block_offset(struct super_block *sb, loff_t off)
+{
+	return (u32)(off & (sb->s_blocksize - 1));
+}
+
+/*
+ * helpers for block size to dentry size conversion.
+ */
+static inline u32 exfat_bytes_to_dentries(loff_t b)
+{
+	return (u32)(b >> DENTRY_SIZE_BITS);
+}
+
+static inline u32 exfat_dentries_to_bytes(u32 dentry)
+{
+	return dentry << DENTRY_SIZE_BITS;
+}
+
+/*
+ * helpers for cluster size to dentry size conversion.
+ */
+static inline u32 exfat_cluster_to_dentries(struct exfat_sb_info *sbi,
+		u32 nr_clusters)
+{
+	return nr_clusters << (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
+}
+
+static inline u32 exfat_dentries_to_cluster(struct exfat_sb_info *sbi,
+		u32 dentry)
+{
+	return dentry >> (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
+}
+
+/* super.c */
+int exfat_set_volume_dirty(struct super_block *sb);
+int exfat_clear_volume_dirty(struct super_block *sb);
+
+/* fatent.c */
+#define exfat_get_next_cluster(sb, pclu) \
+	exfat_cluster_walk(sb, (pclu), 1, ALLOC_FAT_CHAIN)
+
+int exfat_alloc_cluster(struct inode *inode, unsigned int num_alloc,
+		struct exfat_chain *p_chain, bool sync_bmap, bool contig);
+int exfat_free_cluster(struct inode *inode, struct exfat_chain *p_chain);
+int exfat_ent_get(struct super_block *sb, unsigned int loc,
+		unsigned int *content, struct buffer_head **last);
+int exfat_ent_set(struct super_block *sb, unsigned int loc,
+		unsigned int content);
+int exfat_chain_cont_cluster(struct super_block *sb, unsigned int chain,
+		unsigned int len);
+int exfat_zeroed_cluster(struct inode *dir, unsigned int clu);
+int exfat_find_last_cluster(struct super_block *sb, struct exfat_chain *p_chain,
+		unsigned int *ret_clu);
+int exfat_count_num_clusters(struct super_block *sb,
+		struct exfat_chain *p_chain, unsigned int *ret_count);
+int exfat_blk_readahead(struct super_block *sb, sector_t sec,
+		sector_t *ra, blkcnt_t *ra_cnt, sector_t end);
+
+static inline int
+exfat_cluster_walk(struct super_block *sb, unsigned int *clu,
+		unsigned int step, int flags)
+{
+	struct buffer_head *bh = NULL;
+
+	if (flags == ALLOC_NO_FAT_CHAIN) {
+		(*clu) += step;
+		return 0;
+	}
+
+	while (step--) {
+		if (exfat_ent_get(sb, *clu, clu, &bh))
+			return -EIO;
+	}
+	brelse(bh);
+
+	return 0;
+}
+
+/* balloc.c */
+int exfat_load_bitmap(struct super_block *sb);
+void exfat_free_bitmap(struct exfat_sb_info *sbi);
+int exfat_set_bitmap(struct super_block *sb, unsigned int clu, bool sync);
+int exfat_clear_bitmap(struct super_block *sb, unsigned int clu, bool sync);
+bool exfat_test_bitmap(struct super_block *sb, unsigned int clu);
+unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu);
+int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count);
+int exfat_trim_fs(struct inode *inode, struct fstrim_range *range);
+
+/* file.c */
+extern const struct file_operations exfat_file_operations;
+int __exfat_truncate(struct inode *inode);
+int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		  struct iattr *attr);
+int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
+		  struct kstat *stat, unsigned int request_mask,
+		  unsigned int query_flags);
+struct file_kattr;
+int exfat_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
+int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
+long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
+long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
+				unsigned long arg);
+int exfat_force_shutdown(struct super_block *sb, u32 flags);
+
+/* namei.c */
+extern const struct dentry_operations exfat_dentry_ops;
+extern const struct dentry_operations exfat_utf8_dentry_ops;
+int exfat_find_empty_entry(struct inode *inode,
+		struct exfat_chain *p_dir, int num_entries,
+			   struct exfat_entry_set_cache *es);
+
+/* cache.c */
+int exfat_cache_init(void);
+void exfat_cache_shutdown(void);
+void exfat_cache_inval_inode(struct inode *inode);
+int exfat_get_cluster(struct inode *inode, unsigned int cluster,
+		unsigned int *dclus, unsigned int *count, unsigned int *last_dclus);
+
+/* dir.c */
+extern const struct inode_operations exfat_dir_inode_operations;
+extern const struct file_operations exfat_dir_operations;
+unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
+void exfat_init_dir_entry(struct exfat_entry_set_cache *es,
+		unsigned int type, unsigned int start_clu,
+		unsigned long long size, struct timespec64 *ts);
+void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries,
+		struct exfat_uni_name *p_uniname,
+		struct exfat_entry_set_cache *old_es, int num_extra);
+void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es,
+		int order, bool free_benign);
+void exfat_update_dir_chksum(struct exfat_entry_set_cache *es);
+int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
+int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
+		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
+		struct exfat_hint *hint_opt);
+int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
+struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
+		struct exfat_chain *p_dir, int entry, struct buffer_head **bh);
+struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
+		int num);
+int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
+		struct super_block *sb, struct exfat_chain *p_dir, int entry,
+		unsigned int num_entries);
+#define exfat_get_dentry_set_by_ei(es, sb, ei)		\
+	exfat_get_dentry_set(es, sb, &(ei)->dir, (ei)->entry, ES_ALL_ENTRIES)
+int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es,
+		struct super_block *sb, struct exfat_chain *p_dir, int entry,
+		unsigned int num_entries);
+int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync);
+int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
+int exfat_read_volume_label(struct super_block *sb,
+			    struct exfat_uni_name *label_out);
+int exfat_write_volume_label(struct super_block *sb,
+			     struct exfat_uni_name *label);
+
+static inline int exfat_chain_advance(struct super_block *sb,
+		struct exfat_chain *chain, unsigned int step)
+{
+	unsigned int clu = chain->dir;
+
+	if (unlikely(chain->size < step))
+		return -EIO;
+
+	if (exfat_cluster_walk(sb, &clu, step, chain->flags))
+		return -EIO;
+
+	chain->size -= step;
+
+	if (chain->size == 0 && chain->flags == ALLOC_NO_FAT_CHAIN)
+		chain->dir = EXFAT_EOF_CLUSTER;
+	else
+		chain->dir = clu;
+
+	return 0;
+}
+
+/* inode.c */
+extern const struct inode_operations exfat_file_inode_operations;
+void exfat_sync_inode(struct inode *inode);
+struct inode *exfat_build_inode(struct super_block *sb,
+		struct exfat_dir_entry *info, loff_t i_pos);
+void exfat_hash_inode(struct inode *inode, loff_t i_pos);
+void exfat_unhash_inode(struct inode *inode);
+struct inode *exfat_iget(struct super_block *sb, loff_t i_pos);
+int __exfat_write_inode(struct inode *inode, int sync);
+int exfat_write_inode(struct inode *inode, struct writeback_control *wbc);
+void exfat_evict_inode(struct inode *inode);
+int exfat_map_cluster(struct inode *inode, unsigned int clu_offset,
+		unsigned int *clu, unsigned int *count, int create,
+		bool *balloc);
+
+/* exfat/nls.c */
+unsigned short exfat_toupper(struct super_block *sb, unsigned short a);
+int exfat_uniname_ncmp(struct super_block *sb, unsigned short *a,
+		unsigned short *b, unsigned int len);
+int exfat_utf16_to_nls(struct super_block *sb,
+		struct exfat_uni_name *uniname, unsigned char *p_cstring,
+		int len);
+int exfat_nls_to_utf16(struct super_block *sb,
+		const unsigned char *p_cstring, const int len,
+		struct exfat_uni_name *uniname, int *p_lossy);
+int exfat_create_upcase_table(struct super_block *sb);
+void exfat_free_upcase_table(struct exfat_sb_info *sbi);
+
+/* exfat/misc.c */
+void __exfat_fs_error(struct super_block *sb, int report, const char *fmt, ...)
+		__printf(3, 4) __cold;
+#define exfat_fs_error(sb, fmt, args...)          \
+		__exfat_fs_error(sb, 1, fmt, ## args)
+#define exfat_fs_error_ratelimit(sb, fmt, args...) \
+		__exfat_fs_error(sb, __ratelimit(&EXFAT_SB(sb)->ratelimit), \
+		fmt, ## args)
+
+/* expand to pr_*() with prefix */
+#define exfat_err(sb, fmt, ...)						\
+	pr_err("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
+#define exfat_warn(sb, fmt, ...)					\
+	pr_warn("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
+#define exfat_info(sb, fmt, ...)					\
+	pr_info("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
+#define exfat_debug(sb, fmt, ...)					\
+	pr_debug("exFAT-fs (%s): " fmt "\n", (sb)->s_id, ##__VA_ARGS__)
+
+void exfat_get_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 tz, __le16 time, __le16 date, u8 time_cs);
+void exfat_truncate_atime(struct timespec64 *ts);
+void exfat_truncate_inode_atime(struct inode *inode);
+void exfat_set_entry_time(struct exfat_sb_info *sbi, struct timespec64 *ts,
+		u8 *tz, __le16 *time, __le16 *date, u8 *time_cs);
+u16 exfat_calc_chksum16(void *data, int len, u16 chksum, int type);
+u32 exfat_calc_chksum32(void *data, int len, u32 chksum, int type);
+int exfat_update_bh(struct buffer_head *bh, int sync);
+int exfat_update_bhs(struct buffer_head **bhs, int nr_bhs, int sync);
+void exfat_chain_set(struct exfat_chain *ec, unsigned int dir,
+		unsigned int size, unsigned char flags);
+void exfat_chain_dup(struct exfat_chain *dup, struct exfat_chain *ec);
+
+#endif /* !_EXFAT_FS_H */