1 files changed, 378 insertions, 78 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 9b7fc7d3c7f1..7f16049387d1 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -35,18 +35,45 @@
 /** Default max number of pages that can be used in a single read request */
 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
 
-/** Maximum of max_pages received in init_out */
-#define FUSE_MAX_MAX_PAGES 256
-
 /** Bias for fi->writectr, meaning new writepages must not be sent */
 #define FUSE_NOWRITE INT_MIN
 
-/** It could be as large as PATH_MAX, but would that have any uses? */
-#define FUSE_NAME_MAX 1024
+/** Maximum length of a filename, not including terminating null */
+
+/* maximum, small enough for FUSE_MIN_READ_BUFFER*/
+#define FUSE_NAME_LOW_MAX 1024
+/* maximum, but needs a request buffer > FUSE_MIN_READ_BUFFER */
+#define FUSE_NAME_MAX (PATH_MAX - 1)
 
 /** Number of dentries for each connection in the control filesystem */
 #define FUSE_CTL_NUM_DENTRIES 5
 
+/* Frequency (in seconds) of request timeout checks, if opted into */
+#define FUSE_TIMEOUT_TIMER_FREQ 15
+
+/** Frequency (in jiffies) of request timeout checks, if opted into */
+extern const unsigned long fuse_timeout_timer_freq;
+
+/*
+ * Dentries invalidation workqueue period, in seconds.  The value of this
+ * parameter shall be >= FUSE_DENTRY_INVAL_FREQ_MIN seconds, or 0 (zero), in
+ * which case no workqueue will be created.
+ */
+extern unsigned inval_wq __read_mostly;
+
+/** Maximum of max_pages received in init_out */
+extern unsigned int fuse_max_pages_limit;
+/*
+ * Default timeout (in seconds) for the server to reply to a request
+ * before the connection is aborted, if no timeout was specified on mount.
+ */
+extern unsigned int fuse_default_req_timeout;
+/*
+ * Max timeout (in seconds) for the server to reply to a request before
+ * the connection is aborted.
+ */
+extern unsigned int fuse_max_req_timeout;
+
 /** List of active connections */
 extern struct list_head fuse_conn_list;
 
@@ -54,8 +81,8 @@ extern struct list_head fuse_conn_list;
 extern struct mutex fuse_mutex;
 
 /** Module parameters */
-extern unsigned max_user_bgreq;
-extern unsigned max_user_congthresh;
+extern unsigned int max_user_bgreq;
+extern unsigned int max_user_congthresh;
 
 /* One forget request */
 struct fuse_forget_link {
@@ -63,6 +90,29 @@ struct fuse_forget_link {
 	struct fuse_forget_link *next;
 };
 
+/* Submount lookup tracking */
+struct fuse_submount_lookup {
+	/** Refcount */
+	refcount_t count;
+
+	/** Unique ID, which identifies the inode between userspace
+	 * and kernel */
+	u64 nodeid;
+
+	/** The request used for sending the FORGET message */
+	struct fuse_forget_link *forget;
+};
+
+/** Container for data related to mapping to backing file */
+struct fuse_backing {
+	struct file *file;
+	struct cred *cred;
+
+	/** refcount */
+	refcount_t count;
+	struct rcu_head rcu;
+};
+
 /** FUSE inode */
 struct fuse_inode {
 	/** Inode data */
@@ -88,6 +138,9 @@ struct fuse_inode {
 	    preserve the original mode */
 	umode_t orig_i_mode;
 
+	/* Cache birthtime */
+	struct timespec64 i_btime;
+
 	/** 64 bit inode number */
 	u64 orig_ino;
 
@@ -95,7 +148,7 @@ struct fuse_inode {
 	u64 attr_version;
 
 	union {
-		/* Write related fields (regular file only) */
+		/* read/write io cache (regular file only) */
 		struct {
 			/* Files usable in writepage.  Protected by fi->lock */
 			struct list_head write_files;
@@ -107,11 +160,14 @@ struct fuse_inode {
 			 * (FUSE_NOWRITE) means more writes are blocked */
 			int writectr;
 
+			/** Number of files/maps using page cache */
+			int iocachectr;
+
 			/* Waitq for writepage completion */
 			wait_queue_head_t page_waitq;
 
-			/* List of writepage requestst (pending or sent) */
-			struct rb_root writepages;
+			/* waitq for direct-io completion */
+			wait_queue_head_t direct_io_waitq;
 		};
 
 		/* readdir cache (directory only) */
@@ -155,6 +211,18 @@ struct fuse_inode {
 	 */
 	struct fuse_inode_dax *dax;
 #endif
+	/** Submount specific lookup tracking */
+	struct fuse_submount_lookup *submount_lookup;
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	/** Reference to backing file in passthrough mode */
+	struct fuse_backing *fb;
+#endif
+
+	/*
+	 * The underlying inode->i_blkbits value will not be modified,
+	 * so preserve the blocksize specified by the server.
+	 */
+	u8 cached_i_blkbits;
 };
 
 /** FUSE inode state bits */
@@ -167,19 +235,28 @@ enum {
 	FUSE_I_SIZE_UNSTABLE,
 	/* Bad inode */
 	FUSE_I_BAD,
+	/* Has btime */
+	FUSE_I_BTIME,
+	/* Wants or already has page cache IO */
+	FUSE_I_CACHE_IO_MODE,
+	/*
+	 * Client has exclusive access to the inode, either because fs is local
+	 * or the fuse server has an exclusive "lease" on distributed fs
+	 */
+	FUSE_I_EXCLUSIVE,
 };
 
 struct fuse_conn;
 struct fuse_mount;
-struct fuse_release_args;
+union fuse_file_args;
 
 /** FUSE specific file data */
 struct fuse_file {
 	/** Fuse connection for this file */
 	struct fuse_mount *fm;
 
-	/* Argument space reserved for release */
-	struct fuse_release_args *release_args;
+	/* Argument space reserved for open/release */
+	union fuse_file_args *args;
 
 	/** Kernel file handle guaranteed to be unique */
 	u64 kh;
@@ -201,12 +278,6 @@ struct fuse_file {
 
 	/* Readdir related */
 	struct {
-		/*
-		 * Protects below fields against (crazy) parallel readdir on
-		 * same open file.  Uncontended in the normal case.
-		 */
-		struct mutex lock;
-
 		/* Dir stream position */
 		loff_t pos;
 
@@ -224,6 +295,15 @@ struct fuse_file {
 	/** Wait queue head for poll */
 	wait_queue_head_t poll_wait;
 
+	/** Does file hold a fi->iocachectr refcount? */
+	enum { IOM_NONE, IOM_CACHED, IOM_UNCACHED } iomode;
+
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	/** Reference to backing file in passthrough mode */
+	struct file *passthrough;
+	const struct cred *cred;
+#endif
+
 	/** Has flock been performed on this file? */
 	bool flock:1;
 };
@@ -240,8 +320,8 @@ struct fuse_arg {
 	void *value;
 };
 
-/** FUSE page descriptor */
-struct fuse_page_desc {
+/** FUSE folio descriptor */
+struct fuse_folio_desc {
 	unsigned int length;
 	unsigned int offset;
 };
@@ -263,16 +343,33 @@ struct fuse_args {
 	bool page_replace:1;
 	bool may_block:1;
 	bool is_ext:1;
-	struct fuse_in_arg in_args[3];
+	bool is_pinned:1;
+	bool invalidate_vmap:1;
+	struct fuse_in_arg in_args[4];
 	struct fuse_arg out_args[2];
 	void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
+	/* Used for kvec iter backed by vmalloc address */
+	void *vmap_base;
 };
 
 struct fuse_args_pages {
 	struct fuse_args args;
-	struct page **pages;
-	struct fuse_page_desc *descs;
-	unsigned int num_pages;
+	struct folio **folios;
+	struct fuse_folio_desc *descs;
+	unsigned int num_folios;
+};
+
+struct fuse_release_args {
+	struct fuse_args args;
+	struct fuse_release_in inarg;
+	struct inode *inode;
+};
+
+union fuse_file_args {
+	/* Used during open() */
+	struct fuse_open_out open_outarg;
+	/* Used during release() */
+	struct fuse_release_args release_args;
 };
 
 #define FUSE_ARGS(args) struct fuse_args args = {}
@@ -316,6 +413,7 @@ struct fuse_io_priv {
  * FR_FINISHED:		request is finished
  * FR_PRIVATE:		request is on private list
  * FR_ASYNC:		request is asynchronous
+ * FR_URING:		request is handled through fuse-io-uring
  */
 enum fuse_req_flag {
 	FR_ISREPLY,
@@ -330,6 +428,7 @@ enum fuse_req_flag {
 	FR_FINISHED,
 	FR_PRIVATE,
 	FR_ASYNC,
+	FR_URING,
 };
 
 /**
@@ -376,6 +475,13 @@ struct fuse_req {
 
 	/** fuse_mount this request belongs to */
 	struct fuse_mount *fm;
+
+#ifdef CONFIG_FUSE_IO_URING
+	void *ring_entry;
+	void *ring_queue;
+#endif
+	/** When (in jiffies) the request was created */
+	unsigned long create_time;
 };
 
 struct fuse_iqueue;
@@ -390,22 +496,19 @@ struct fuse_iqueue;
  */
 struct fuse_iqueue_ops {
 	/**
-	 * Signal that a forget has been queued
+	 * Send one forget
 	 */
-	void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
-		__releases(fiq->lock);
+	void (*send_forget)(struct fuse_iqueue *fiq, struct fuse_forget_link *link);
 
 	/**
-	 * Signal that an INTERRUPT request has been queued
+	 * Send interrupt for request
 	 */
-	void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
-		__releases(fiq->lock);
+	void (*send_interrupt)(struct fuse_iqueue *fiq, struct fuse_req *req);
 
 	/**
-	 * Signal that a request has been queued
+	 * Send one request
 	 */
-	void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
-		__releases(fiq->lock);
+	void (*send_req)(struct fuse_iqueue *fiq, struct fuse_req *req);
 
 	/**
 	 * Clean up when fuse_iqueue is destroyed
@@ -548,6 +651,11 @@ struct fuse_conn {
 	/** Number of fuse_dev's */
 	atomic_t dev_count;
 
+	/** Current epoch for up-to-date dentries */
+	atomic_t epoch;
+
+	struct work_struct epoch_work;
+
 	struct rcu_head rcu;
 
 	/** The user id for this mount */
@@ -762,6 +870,9 @@ struct fuse_conn {
 	/** Does the filesystem support copy_file_range? */
 	unsigned no_copy_file_range:1;
 
+	/** Does the filesystem support copy_file_range_64? */
+	unsigned no_copy_file_range_64:1;
+
 	/* Send DESTROY request */
 	unsigned int destroy:1;
 
@@ -792,30 +903,54 @@ struct fuse_conn {
 	/* Is tmpfile not implemented by fs? */
 	unsigned int no_tmpfile:1;
 
+	/* Relax restrictions to allow shared mmap in FOPEN_DIRECT_IO mode */
+	unsigned int direct_io_allow_mmap:1;
+
+	/* Is statx not implemented by fs? */
+	unsigned int no_statx:1;
+
+	/** Passthrough support for read/write IO */
+	unsigned int passthrough:1;
+
+	/* Use pages instead of pointer for kernel I/O */
+	unsigned int use_pages_for_kvec_io:1;
+
+	/* Is link not implemented by fs? */
+	unsigned int no_link:1;
+
+	/* Is synchronous FUSE_INIT allowed? */
+	unsigned int sync_init:1;
+
+	/* Use io_uring for communication */
+	unsigned int io_uring;
+
+	/** Maximum stack depth for passthrough backing files */
+	int max_stack_depth;
+
 	/** The number of requests waiting for completion */
 	atomic_t num_waiting;
 
 	/** Negotiated minor version */
 	unsigned minor;
 
-	/** Entry on the fuse_mount_list */
+	/** Entry on the fuse_conn_list */
 	struct list_head entry;
 
 	/** Device ID from the root super block */
 	dev_t dev;
 
-	/** Dentries in the control filesystem */
-	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
-
-	/** number of dentries used in the above array */
-	int ctl_ndents;
-
 	/** Key for lock owner ID scrambling */
 	u32 scramble_key[4];
 
 	/** Version counter for attribute changes */
 	atomic64_t attr_version;
 
+	/** Version counter for evict inode */
+	atomic64_t evict_ctr;
+
+	/* maximum file name length */
+	u32 name_max;
+
 	/** Called on final put */
 	void (*release)(struct fuse_conn *);
 
@@ -841,6 +976,25 @@ struct fuse_conn {
 
 	/* New writepages go into this bucket */
 	struct fuse_sync_bucket __rcu *curr_bucket;
+
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	/** IDR for backing files ids */
+	struct idr backing_files_map;
+#endif
+
+#ifdef CONFIG_FUSE_IO_URING
+	/**  uring connection information*/
+	struct fuse_ring *ring;
+#endif
+
+	/** Only used if the connection opts into request timeouts */
+	struct {
+		/* Worker for checking if any requests have timed out */
+		struct delayed_work work;
+
+		/* Request timeout (in jiffies). 0 = no timeout */
+		unsigned int req_timeout;
+	} timeout;
 };
 
 /*
@@ -862,8 +1016,22 @@ struct fuse_mount {
 
 	/* Entry on fc->mounts */
 	struct list_head fc_entry;
+	struct rcu_head rcu;
 };
 
+/*
+ * Empty header for FUSE opcodes without specific header needs.
+ * Used as a placeholder in args->in_args[0] for consistency
+ * across all FUSE operations, simplifying request handling.
+ */
+struct fuse_zero_header {};
+
+static inline void fuse_set_zero_arg0(struct fuse_args *args)
+{
+	args->in_args[0].size = sizeof(struct fuse_zero_header);
+	args->in_args[0].value = NULL;
+}
+
 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
 {
 	return sb->s_fs_info;
@@ -884,7 +1052,7 @@ static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 	return get_fuse_mount_super(inode->i_sb)->fc;
 }
 
-static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
+static inline struct fuse_inode *get_fuse_inode(const struct inode *inode)
 {
 	return container_of(inode, struct fuse_inode, inode);
 }
@@ -904,6 +1072,11 @@ static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
 	return atomic64_read(&fc->attr_version);
 }
 
+static inline u64 fuse_get_evict_ctr(struct fuse_conn *fc)
+{
+	return atomic64_read(&fc->evict_ctr);
+}
+
 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
 				    struct fuse_attr *attr)
 {
@@ -913,7 +1086,6 @@ static inline bool fuse_stale_inode(const struct inode *inode, int generation,
 
 static inline void fuse_make_bad(struct inode *inode)
 {
-	remove_inode_hash(inode);
 	set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
 }
 
@@ -922,25 +1094,32 @@ static inline bool fuse_is_bad(struct inode *inode)
 	return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
 }
 
-static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
-					     struct fuse_page_desc **desc)
+static inline bool fuse_inode_is_exclusive(const struct inode *inode)
 {
-	struct page **pages;
+	const struct fuse_inode *fi = get_fuse_inode(inode);
 
-	pages = kzalloc(npages * (sizeof(struct page *) +
-				  sizeof(struct fuse_page_desc)), flags);
-	*desc = (void *) (pages + npages);
+	return test_bit(FUSE_I_EXCLUSIVE, &fi->state);
+}
 
-	return pages;
+static inline struct folio **fuse_folios_alloc(unsigned int nfolios, gfp_t flags,
+					       struct fuse_folio_desc **desc)
+{
+	struct folio **folios;
+
+	folios = kzalloc(nfolios * (sizeof(struct folio *) +
+				    sizeof(struct fuse_folio_desc)), flags);
+	*desc = (void *) (folios + nfolios);
+
+	return folios;
 }
 
-static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
-					       unsigned int index,
-					       unsigned int nr_pages)
+static inline void fuse_folio_descs_length_init(struct fuse_folio_desc *descs,
+						unsigned int index,
+						unsigned int nr_folios)
 {
 	int i;
 
-	for (i = index; i < index + nr_pages; i++)
+	for (i = index; i < index + nr_folios; i++)
 		descs[i].length = PAGE_SIZE - descs[i].offset;
 }
 
@@ -957,14 +1136,14 @@ static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
 extern const struct file_operations fuse_dev_operations;
 
 extern const struct dentry_operations fuse_dentry_operations;
-extern const struct dentry_operations fuse_root_dentry_operations;
 
 /**
  * Get a filled in inode
  */
 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 			int generation, struct fuse_attr *attr,
-			u64 attr_valid, u64 attr_version);
+			u64 attr_valid, u64 attr_version,
+			u64 evict_ctr);
 
 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
 		     struct fuse_entry_out *outarg, struct inode **inode);
@@ -977,10 +1156,6 @@ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 
 struct fuse_forget_link *fuse_alloc_forget(void);
 
-struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
-					     unsigned int max,
-					     unsigned int *countp);
-
 /*
  * Initialize READ or READDIR request
  */
@@ -993,7 +1168,7 @@ struct fuse_io_args {
 		struct {
 			struct fuse_write_in in;
 			struct fuse_write_out out;
-			bool page_locked;
+			bool folio_locked;
 		} write;
 	};
 	struct fuse_args_pages ap;
@@ -1005,14 +1180,9 @@ void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
 			 size_t count, int opcode);
 
 
-/**
- * Send OPEN or OPENDIR request
- */
-int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
-
-struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
+struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release);
 void fuse_file_free(struct fuse_file *ff);
-void fuse_finish_open(struct inode *inode, struct file *file);
+int fuse_finish_open(struct inode *inode, struct file *file);
 
 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
 		       unsigned int flags);
@@ -1058,10 +1228,13 @@ void fuse_init_symlink(struct inode *inode);
  * Change attributes of an inode
  */
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			    struct fuse_statx *sx,
 			    u64 attr_valid, u64 attr_version);
 
 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
-				   u64 attr_valid, u32 cache_mask);
+				   struct fuse_statx *sx,
+				   u64 attr_valid, u32 cache_mask,
+				   u64 evict_ctr);
 
 u32 fuse_get_cache_mask(struct inode *inode);
 
@@ -1081,11 +1254,31 @@ void __exit fuse_ctl_cleanup(void);
 /**
  * Simple request sending that does request allocation and freeing
  */
-ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
+ssize_t __fuse_simple_request(struct mnt_idmap *idmap,
+			      struct fuse_mount *fm,
+			      struct fuse_args *args);
+
+static inline ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args)
+{
+	return __fuse_simple_request(&invalid_mnt_idmap, fm, args);
+}
+
+static inline ssize_t fuse_simple_idmap_request(struct mnt_idmap *idmap,
+						struct fuse_mount *fm,
+						struct fuse_args *args)
+{
+	return __fuse_simple_request(idmap, fm, args);
+}
+
 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
 			   gfp_t gfp_flags);
 
 /**
+ * Assign a unique id to a fuse request
+ */
+void fuse_request_assign_unique(struct fuse_iqueue *fiq, struct fuse_req *req);
+
+/**
  * End a finished request
  */
 void fuse_request_end(struct fuse_req *req);
@@ -1094,6 +1287,14 @@ void fuse_request_end(struct fuse_req *req);
 void fuse_abort_conn(struct fuse_conn *fc);
 void fuse_wait_aborted(struct fuse_conn *fc);
 
+/* Check if any requests timed out */
+void fuse_check_timeout(struct work_struct *work);
+
+void fuse_dentry_tree_init(void);
+void fuse_dentry_tree_cleanup(void);
+
+void fuse_epoch_work(struct work_struct *work);
+
 /**
  * Invalidate inode attributes
  */
@@ -1111,7 +1312,10 @@ void fuse_invalidate_entry_cache(struct dentry *entry);
 
 void fuse_invalidate_atime(struct inode *inode);
 
-u64 entry_attr_timeout(struct fuse_entry_out *o);
+u64 fuse_time_to_jiffies(u64 sec, u32 nsec);
+#define ATTR_TIMEOUT(o) \
+	fuse_time_to_jiffies((o)->attr_valid, (o)->attr_valid_nsec)
+
 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
 
 /**
@@ -1120,6 +1324,11 @@ void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 
 /**
+ * Initialize the fuse processing queue
+ */
+void fuse_pqueue_init(struct fuse_pqueue *fpq);
+
+/**
  * Initialize fuse_conn
  */
 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
@@ -1135,7 +1344,7 @@ struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
 struct fuse_dev *fuse_dev_alloc(void);
 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
 void fuse_dev_free(struct fuse_dev *fud);
-void fuse_send_init(struct fuse_mount *fm);
+int fuse_send_init(struct fuse_mount *fm);
 
 /**
  * Fill in superblock and initialize fuse connection
@@ -1227,6 +1436,12 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
 			     u64 child_nodeid, struct qstr *name, u32 flags);
 
+/*
+ * Try to prune this inode.  If neither the inode itself nor dentries associated
+ * with this inode have any external reference, then the inode can be freed.
+ */
+void fuse_try_prune_one_inode(struct fuse_conn *fc, u64 nodeid);
+
 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
 		 bool isdir);
 
@@ -1254,8 +1469,8 @@ bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
 
-int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
-		    struct file *file);
+int fuse_do_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		    struct iattr *attr, struct file *file);
 
 void fuse_set_initialized(struct fuse_conn *fc);
 
@@ -1268,7 +1483,7 @@ ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
 		      size_t size);
 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
 int fuse_removexattr(struct inode *inode, const char *name);
-extern const struct xattr_handler *fuse_xattr_handlers[];
+extern const struct xattr_handler * const fuse_xattr_handlers[];
 
 struct posix_acl;
 struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu);
@@ -1313,15 +1528,100 @@ void fuse_dax_cancel_work(struct fuse_conn *fc);
 long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
 long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg);
-int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
+int fuse_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
 int fuse_fileattr_set(struct mnt_idmap *idmap,
-		      struct dentry *dentry, struct fileattr *fa);
+		      struct dentry *dentry, struct file_kattr *fa);
 
-/* file.c */
+/* iomode.c */
+int fuse_file_cached_io_open(struct inode *inode, struct fuse_file *ff);
+int fuse_inode_uncached_io_start(struct fuse_inode *fi,
+				 struct fuse_backing *fb);
+void fuse_inode_uncached_io_end(struct fuse_inode *fi);
 
+int fuse_file_io_open(struct file *file, struct inode *inode);
+void fuse_file_io_release(struct fuse_file *ff, struct inode *inode);
+
+/* file.c */
 struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
 				 unsigned int open_flags, bool isdir);
 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
 		       unsigned int open_flags, fl_owner_t id, bool isdir);
 
+/* backing.c */
+#ifdef CONFIG_FUSE_PASSTHROUGH
+struct fuse_backing *fuse_backing_get(struct fuse_backing *fb);
+void fuse_backing_put(struct fuse_backing *fb);
+struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc, int backing_id);
+#else
+
+static inline struct fuse_backing *fuse_backing_get(struct fuse_backing *fb)
+{
+	return NULL;
+}
+
+static inline void fuse_backing_put(struct fuse_backing *fb)
+{
+}
+static inline struct fuse_backing *fuse_backing_lookup(struct fuse_conn *fc,
+						       int backing_id)
+{
+	return NULL;
+}
+#endif
+
+void fuse_backing_files_init(struct fuse_conn *fc);
+void fuse_backing_files_free(struct fuse_conn *fc);
+int fuse_backing_open(struct fuse_conn *fc, struct fuse_backing_map *map);
+int fuse_backing_close(struct fuse_conn *fc, int backing_id);
+
+/* passthrough.c */
+static inline struct fuse_backing *fuse_inode_backing(struct fuse_inode *fi)
+{
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	return READ_ONCE(fi->fb);
+#else
+	return NULL;
+#endif
+}
+
+static inline struct fuse_backing *fuse_inode_backing_set(struct fuse_inode *fi,
+							  struct fuse_backing *fb)
+{
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	return xchg(&fi->fb, fb);
+#else
+	return NULL;
+#endif
+}
+
+struct fuse_backing *fuse_passthrough_open(struct file *file, int backing_id);
+void fuse_passthrough_release(struct fuse_file *ff, struct fuse_backing *fb);
+
+static inline struct file *fuse_file_passthrough(struct fuse_file *ff)
+{
+#ifdef CONFIG_FUSE_PASSTHROUGH
+	return ff->passthrough;
+#else
+	return NULL;
+#endif
+}
+
+ssize_t fuse_passthrough_read_iter(struct kiocb *iocb, struct iov_iter *iter);
+ssize_t fuse_passthrough_write_iter(struct kiocb *iocb, struct iov_iter *iter);
+ssize_t fuse_passthrough_splice_read(struct file *in, loff_t *ppos,
+				     struct pipe_inode_info *pipe,
+				     size_t len, unsigned int flags);
+ssize_t fuse_passthrough_splice_write(struct pipe_inode_info *pipe,
+				      struct file *out, loff_t *ppos,
+				      size_t len, unsigned int flags);
+ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma);
+
+#ifdef CONFIG_SYSCTL
+extern int fuse_sysctl_register(void);
+extern void fuse_sysctl_unregister(void);
+#else
+#define fuse_sysctl_register()		(0)
+#define fuse_sysctl_unregister()	do { } while (0)
+#endif /* CONFIG_SYSCTL */
+
 #endif /* _FS_FUSE_I_H */