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FUSE: Filesystem in Userspace
Copyright (C) 2001-2008 Miklos Szeredi <>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
#ifndef _FS_FUSE_I_H
#define _FS_FUSE_I_H
#ifndef pr_fmt
# define pr_fmt(fmt) "fuse: " fmt
#include <linux/fuse.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/backing-dev.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/rbtree.h>
#include <linux/poll.h>
#include <linux/workqueue.h>
#include <linux/kref.h>
#include <linux/xattr.h>
#include <linux/pid_namespace.h>
#include <linux/refcount.h>
#include <linux/user_namespace.h>
/** Default max number of pages that can be used in a single read request */
/** 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 */
/** It could be as large as PATH_MAX, but would that have any uses? */
#define FUSE_NAME_MAX 1024
/** Number of dentries for each connection in the control filesystem */
/** List of active connections */
extern struct list_head fuse_conn_list;
/** Global mutex protecting fuse_conn_list and the control filesystem */
extern struct mutex fuse_mutex;
/** Module parameters */
extern unsigned max_user_bgreq;
extern unsigned max_user_congthresh;
/* One forget request */
struct fuse_forget_link {
struct fuse_forget_one forget_one;
struct fuse_forget_link *next;
/** FUSE inode */
struct fuse_inode {
/** Inode data */
struct inode inode;
/** Unique ID, which identifies the inode between userspace
* and kernel */
u64 nodeid;
/** Number of lookups on this inode */
u64 nlookup;
/** The request used for sending the FORGET message */
struct fuse_forget_link *forget;
/** Time in jiffies until the file attributes are valid */
u64 i_time;
/* Which attributes are invalid */
u32 inval_mask;
/** The sticky bit in inode->i_mode may have been removed, so
preserve the original mode */
umode_t orig_i_mode;
/** 64 bit inode number */
u64 orig_ino;
/** Version of last attribute change */
u64 attr_version;
union {
/* Write related fields (regular file only) */
struct {
/* Files usable in writepage. Protected by fi->lock */
struct list_head write_files;
/* Writepages pending on truncate or fsync */
struct list_head queued_writes;
/* Number of sent writes, a negative bias
* (FUSE_NOWRITE) means more writes are blocked */
int writectr;
/* Waitq for writepage completion */
wait_queue_head_t page_waitq;
/* List of writepage requestst (pending or sent) */
struct rb_root writepages;
/* readdir cache (directory only) */
struct {
/* true if fully cached */
bool cached;
/* size of cache */
loff_t size;
/* position at end of cache (position of next entry) */
loff_t pos;
/* version of the cache */
u64 version;
/* modification time of directory when cache was
* started */
struct timespec64 mtime;
/* iversion of directory when cache was started */
u64 iversion;
/* protects above fields */
spinlock_t lock;
} rdc;
/** Miscellaneous bits describing inode state */
unsigned long state;
/** Lock for serializing lookup and readdir for back compatibility*/
struct mutex mutex;
/** Lock to protect write related fields */
spinlock_t lock;
* Dax specific inode data
struct fuse_inode_dax *dax;
/** FUSE inode state bits */
enum {
/** Advise readdirplus */
/** Initialized with readdirplus */
/** An operation changing file size is in progress */
/* Bad inode */
struct fuse_conn;
struct fuse_mount;
struct fuse_release_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;
/** Kernel file handle guaranteed to be unique */
u64 kh;
/** File handle used by userspace */
u64 fh;
/** Node id of this file */
u64 nodeid;
/** Refcount */
refcount_t count;
/** FOPEN_* flags returned by open */
u32 open_flags;
/** Entry on inode's write_files list */
struct list_head write_entry;
/* 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;
/* Offset in cache */
loff_t cache_off;
/* Version of cache we are reading */
u64 version;
} readdir;
/** RB node to be linked on fuse_conn->polled_files */
struct rb_node polled_node;
/** Wait queue head for poll */
wait_queue_head_t poll_wait;
/** Has flock been performed on this file? */
bool flock:1;
/** One input argument of a request */
struct fuse_in_arg {
unsigned size;
const void *value;
/** One output argument of a request */
struct fuse_arg {
unsigned size;
void *value;
/** FUSE page descriptor */
struct fuse_page_desc {
unsigned int length;
unsigned int offset;
struct fuse_args {
uint64_t nodeid;
uint32_t opcode;
unsigned short in_numargs;
unsigned short out_numargs;
bool force:1;
bool noreply:1;
bool nocreds:1;
bool in_pages:1;
bool out_pages:1;
bool out_argvar:1;
bool page_zeroing:1;
bool page_replace:1;
bool may_block:1;
struct fuse_in_arg in_args[3];
struct fuse_arg out_args[2];
void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
struct fuse_args_pages {
struct fuse_args args;
struct page **pages;
struct fuse_page_desc *descs;
unsigned int num_pages;
#define FUSE_ARGS(args) struct fuse_args args = {}
/** The request IO state (for asynchronous processing) */
struct fuse_io_priv {
struct kref refcnt;
int async;
spinlock_t lock;
unsigned reqs;
ssize_t bytes;
size_t size;
__u64 offset;
bool write;
bool should_dirty;
int err;
struct kiocb *iocb;
struct completion *done;
bool blocking;
#define FUSE_IO_PRIV_SYNC(i) \
{ \
.refcnt = KREF_INIT(1), \
.async = 0, \
.iocb = i, \
* Request flags
* FR_ISREPLY: set if the request has reply
* FR_FORCE: force sending of the request even if interrupted
* FR_BACKGROUND: request is sent in the background
* FR_WAITING: request is counted as "waiting"
* FR_ABORTED: the request was aborted
* FR_INTERRUPTED: the request has been interrupted
* FR_LOCKED: data is being copied to/from the request
* FR_PENDING: request is not yet in userspace
* FR_SENT: request is in userspace, waiting for an answer
* FR_FINISHED: request is finished
* FR_PRIVATE: request is on private list
* FR_ASYNC: request is asynchronous
enum fuse_req_flag {
* A request to the client
* .waitq.lock protects the following fields:
* - FR_LOCKED (may also be modified under fc->lock, tested under both)
struct fuse_req {
/** This can be on either pending processing or io lists in
fuse_conn */
struct list_head list;
/** Entry on the interrupts list */
struct list_head intr_entry;
/* Input/output arguments */
struct fuse_args *args;
/** refcount */
refcount_t count;
/* Request flags, updated with test/set/clear_bit() */
unsigned long flags;
/* The request input header */
struct {
struct fuse_in_header h;
} in;
/* The request output header */
struct {
struct fuse_out_header h;
} out;
/** Used to wake up the task waiting for completion of request*/
wait_queue_head_t waitq;
/** virtio-fs's physically contiguous buffer for in and out args */
void *argbuf;
/** fuse_mount this request belongs to */
struct fuse_mount *fm;
struct fuse_iqueue;
* Input queue callbacks
* Input queue signalling is device-specific. For example, the /dev/fuse file
* uses fiq->waitq and fasync to wake processes that are waiting on queue
* readiness. These callbacks allow other device types to respond to input
* queue activity.
struct fuse_iqueue_ops {
* Signal that a forget has been queued
void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
* Signal that an INTERRUPT request has been queued
void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
* Signal that a request has been queued
void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
* Clean up when fuse_iqueue is destroyed
void (*release)(struct fuse_iqueue *fiq);
/** /dev/fuse input queue operations */
extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
struct fuse_iqueue {
/** Connection established */
unsigned connected;
/** Lock protecting accesses to members of this structure */
spinlock_t lock;
/** Readers of the connection are waiting on this */
wait_queue_head_t waitq;
/** The next unique request id */
u64 reqctr;
/** The list of pending requests */
struct list_head pending;
/** Pending interrupts */
struct list_head interrupts;
/** Queue of pending forgets */
struct fuse_forget_link forget_list_head;
struct fuse_forget_link *forget_list_tail;
/** Batching of FORGET requests (positive indicates FORGET batch) */
int forget_batch;
/** O_ASYNC requests */
struct fasync_struct *fasync;
/** Device-specific callbacks */
const struct fuse_iqueue_ops *ops;
/** Device-specific state */
void *priv;
struct fuse_pqueue {
/** Connection established */
unsigned connected;
/** Lock protecting accessess to members of this structure */
spinlock_t lock;
/** Hash table of requests being processed */
struct list_head *processing;
/** The list of requests under I/O */
struct list_head io;
* Fuse device instance
struct fuse_dev {
/** Fuse connection for this device */
struct fuse_conn *fc;
/** Processing queue */
struct fuse_pqueue pq;
/** list entry on fc->devices */
struct list_head entry;
struct fuse_fs_context {
int fd;
struct file *file;
unsigned int rootmode;
kuid_t user_id;
kgid_t group_id;
bool is_bdev:1;
bool fd_present:1;
bool rootmode_present:1;
bool user_id_present:1;
bool group_id_present:1;
bool default_permissions:1;
bool allow_other:1;
bool destroy:1;
bool no_control:1;
bool no_force_umount:1;
bool legacy_opts_show:1;
bool dax:1;
unsigned int max_read;
unsigned int blksize;
const char *subtype;
/* DAX device, may be NULL */
struct dax_device *dax_dev;
/* fuse_dev pointer to fill in, should contain NULL on entry */
void **fudptr;
struct fuse_sync_bucket {
/* count is a possible scalability bottleneck */
atomic_t count;
wait_queue_head_t waitq;
struct rcu_head rcu;
* A Fuse connection.
* This structure is created, when the root filesystem is mounted, and
* is destroyed, when the client device is closed and the last
* fuse_mount is destroyed.
struct fuse_conn {
/** Lock protecting accessess to members of this structure */
spinlock_t lock;
/** Refcount */
refcount_t count;
/** Number of fuse_dev's */
atomic_t dev_count;
struct rcu_head rcu;
/** The user id for this mount */
kuid_t user_id;
/** The group id for this mount */
kgid_t group_id;
/** The pid namespace for this mount */
struct pid_namespace *pid_ns;
/** The user namespace for this mount */
struct user_namespace *user_ns;
/** Maximum read size */
unsigned max_read;
/** Maximum write size */
unsigned max_write;
/** Maximum number of pages that can be used in a single request */
unsigned int max_pages;
/** Constrain ->max_pages to this value during feature negotiation */
unsigned int max_pages_limit;
/** Input queue */
struct fuse_iqueue iq;
/** The next unique kernel file handle */
atomic64_t khctr;
/** rbtree of fuse_files waiting for poll events indexed by ph */
struct rb_root polled_files;
/** Maximum number of outstanding background requests */
unsigned max_background;
/** Number of background requests at which congestion starts */
unsigned congestion_threshold;
/** Number of requests currently in the background */
unsigned num_background;
/** Number of background requests currently queued for userspace */
unsigned active_background;
/** The list of background requests set aside for later queuing */
struct list_head bg_queue;
/** Protects: max_background, congestion_threshold, num_background,
* active_background, bg_queue, blocked */
spinlock_t bg_lock;
/** Flag indicating that INIT reply has been received. Allocating
* any fuse request will be suspended until the flag is set */
int initialized;
/** Flag indicating if connection is blocked. This will be
the case before the INIT reply is received, and if there
are too many outstading backgrounds requests */
int blocked;
/** waitq for blocked connection */
wait_queue_head_t blocked_waitq;
/** Connection established, cleared on umount, connection
abort and device release */
unsigned connected;
/** Connection aborted via sysfs */
bool aborted;
/** Connection failed (version mismatch). Cannot race with
setting other bitfields since it is only set once in INIT
reply, before any other request, and never cleared */
unsigned conn_error:1;
/** Connection successful. Only set in INIT */
unsigned conn_init:1;
/** Do readpages asynchronously? Only set in INIT */
unsigned async_read:1;
/** Return an unique read error after abort. Only set in INIT */
unsigned abort_err:1;
/** Do not send separate SETATTR request before open(O_TRUNC) */
unsigned atomic_o_trunc:1;
/** Filesystem supports NFS exporting. Only set in INIT */
unsigned export_support:1;
/** write-back cache policy (default is write-through) */
unsigned writeback_cache:1;
/** allow parallel lookups and readdir (default is serialized) */
unsigned parallel_dirops:1;
/** handle fs handles killing suid/sgid/cap on write/chown/trunc */
unsigned handle_killpriv:1;
/** cache READLINK responses in page cache */
unsigned cache_symlinks:1;
/* show legacy mount options */
unsigned int legacy_opts_show:1;
* fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
* write/trunc only if caller did not have CAP_FSETID. sgid is killed
* on write/truncate only if caller did not have CAP_FSETID as well as
* file has group execute permission.
unsigned handle_killpriv_v2:1;
* The following bitfields are only for optimization purposes
* and hence races in setting them will not cause malfunction
/** Is open/release not implemented by fs? */
unsigned no_open:1;
/** Is opendir/releasedir not implemented by fs? */
unsigned no_opendir:1;
/** Is fsync not implemented by fs? */
unsigned no_fsync:1;
/** Is fsyncdir not implemented by fs? */
unsigned no_fsyncdir:1;
/** Is flush not implemented by fs? */
unsigned no_flush:1;
/** Is setxattr not implemented by fs? */
unsigned no_setxattr:1;
/** Does file server support extended setxattr */
unsigned setxattr_ext:1;
/** Is getxattr not implemented by fs? */
unsigned no_getxattr:1;
/** Is listxattr not implemented by fs? */
unsigned no_listxattr:1;
/** Is removexattr not implemented by fs? */
unsigned no_removexattr:1;
/** Are posix file locking primitives not implemented by fs? */
unsigned no_lock:1;
/** Is access not implemented by fs? */
unsigned no_access:1;
/** Is create not implemented by fs? */
unsigned no_create:1;
/** Is interrupt not implemented by fs? */
unsigned no_interrupt:1;
/** Is bmap not implemented by fs? */
unsigned no_bmap:1;
/** Is poll not implemented by fs? */
unsigned no_poll:1;
/** Do multi-page cached writes */
unsigned big_writes:1;
/** Don't apply umask to creation modes */
unsigned dont_mask:1;
/** Are BSD file locking primitives not implemented by fs? */
unsigned no_flock:1;
/** Is fallocate not implemented by fs? */
unsigned no_fallocate:1;
/** Is rename with flags implemented by fs? */
unsigned no_rename2:1;
/** Use enhanced/automatic page cache invalidation. */
unsigned auto_inval_data:1;
/** Filesystem is fully responsible for page cache invalidation. */
unsigned explicit_inval_data:1;
/** Does the filesystem support readdirplus? */
unsigned do_readdirplus:1;
/** Does the filesystem want adaptive readdirplus? */
unsigned readdirplus_auto:1;
/** Does the filesystem support asynchronous direct-IO submission? */
unsigned async_dio:1;
/** Is lseek not implemented by fs? */
unsigned no_lseek:1;
/** Does the filesystem support posix acls? */
unsigned posix_acl:1;
/** Check permissions based on the file mode or not? */
unsigned default_permissions:1;
/** Allow other than the mounter user to access the filesystem ? */
unsigned allow_other:1;
/** Does the filesystem support copy_file_range? */
unsigned no_copy_file_range:1;
/* Send DESTROY request */
unsigned int destroy:1;
/* Delete dentries that have gone stale */
unsigned int delete_stale:1;
/** Do not create entry in fusectl fs */
unsigned int no_control:1;
/** Do not allow MNT_FORCE umount */
unsigned int no_force_umount:1;
/* Auto-mount submounts announced by the server */
unsigned int auto_submounts:1;
/* Propagate syncfs() to server */
unsigned int sync_fs:1;
/** The number of requests waiting for completion */
atomic_t num_waiting;
/** Negotiated minor version */
unsigned minor;
/** Entry on the fuse_mount_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;
/** Called on final put */
void (*release)(struct fuse_conn *);
* Read/write semaphore to hold when accessing the sb of any
* fuse_mount belonging to this connection
struct rw_semaphore killsb;
/** List of device instances belonging to this connection */
struct list_head devices;
/* Dax specific conn data, non-NULL if DAX is enabled */
struct fuse_conn_dax *dax;
/** List of filesystems using this connection */
struct list_head mounts;
/* New writepages go into this bucket */
struct fuse_sync_bucket __rcu *curr_bucket;
* Represents a mounted filesystem, potentially a submount.
* This object allows sharing a fuse_conn between separate mounts to
* allow submounts with dedicated superblocks and thus separate device
* IDs.
struct fuse_mount {
/* Underlying (potentially shared) connection to the FUSE server */
struct fuse_conn *fc;
* Super block for this connection (fc->killsb must be held when
* accessing this).
struct super_block *sb;
/* Entry on fc->mounts */
struct list_head fc_entry;
static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
return sb->s_fs_info;
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
return get_fuse_mount_super(sb)->fc;
static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
return get_fuse_mount_super(inode->i_sb);
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)
return container_of(inode, struct fuse_inode, inode);
static inline u64 get_node_id(struct inode *inode)
return get_fuse_inode(inode)->nodeid;
static inline int invalid_nodeid(u64 nodeid)
return !nodeid || nodeid == FUSE_ROOT_ID;
static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
return atomic64_read(&fc->attr_version);
static inline bool fuse_stale_inode(const struct inode *inode, int generation,
struct fuse_attr *attr)
return inode->i_generation != generation ||
inode_wrong_type(inode, attr->mode);
static inline void fuse_make_bad(struct inode *inode)
set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
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)
struct page **pages;
pages = kzalloc(npages * (sizeof(struct page *) +
sizeof(struct fuse_page_desc)), flags);
*desc = (void *) (pages + npages);
return pages;
static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
unsigned int index,
unsigned int nr_pages)
int i;
for (i = index; i < index + nr_pages; i++)
descs[i].length = PAGE_SIZE - descs[i].offset;
static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
/* Need RCU protection to prevent use after free after the decrement */
if (atomic_dec_and_test(&bucket->count))
/** Device operations */
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);
int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
struct fuse_entry_out *outarg, struct inode **inode);
* Send FORGET command
void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
u64 nodeid, u64 nlookup);
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
struct fuse_io_args {
union {
struct {
struct fuse_read_in in;
u64 attr_ver;
} read;
struct {
struct fuse_write_in in;
struct fuse_write_out out;
bool page_locked;
} write;
struct fuse_args_pages ap;
struct fuse_io_priv *io;
struct fuse_file *ff;
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);
void fuse_file_free(struct fuse_file *ff);
void fuse_finish_open(struct inode *inode, struct file *file);
void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
unsigned int flags);
* Send RELEASE or RELEASEDIR request
void fuse_release_common(struct file *file, bool isdir);
* Send FSYNC or FSYNCDIR request
int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
int datasync, int opcode);
* Notify poll wakeup
int fuse_notify_poll_wakeup(struct fuse_conn *fc,
struct fuse_notify_poll_wakeup_out *outarg);
* Initialize file operations on a regular file
void fuse_init_file_inode(struct inode *inode);
* Initialize inode operations on regular files and special files
void fuse_init_common(struct inode *inode);
* Initialize inode and file operations on a directory
void fuse_init_dir(struct inode *inode);
* Initialize inode operations on a symlink
void fuse_init_symlink(struct inode *inode);
* Change attributes of an inode
void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
u64 attr_valid, u64 attr_version);
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
u64 attr_valid, u32 cache_mask);
u32 fuse_get_cache_mask(struct inode *inode);
* Initialize the client device
int fuse_dev_init(void);
* Cleanup the client device
void fuse_dev_cleanup(void);
int fuse_ctl_init(void);
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);
int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
gfp_t gfp_flags);
* End a finished request
void fuse_request_end(struct fuse_req *req);
/* Abort all requests */
void fuse_abort_conn(struct fuse_conn *fc);
void fuse_wait_aborted(struct fuse_conn *fc);
* Invalidate inode attributes
/* Attributes possibly changed on data modification */
/* Attributes possibly changed on data and/or size modification */
void fuse_invalidate_attr(struct inode *inode);
void fuse_invalidate_attr_mask(struct inode *inode, u32 mask);
void fuse_invalidate_entry_cache(struct dentry *entry);
void fuse_invalidate_atime(struct inode *inode);
u64 entry_attr_timeout(struct fuse_entry_out *o);
void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
* Acquire reference to fuse_conn
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
* Initialize fuse_conn
void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
struct user_namespace *user_ns,
const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
* Release reference to fuse_conn
void fuse_conn_put(struct fuse_conn *fc);
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);
* Fill in superblock and initialize fuse connection
* @sb: partially-initialized superblock to fill in
* @ctx: mount context
int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
* Remove the mount from the connection
* Returns whether this was the last mount
bool fuse_mount_remove(struct fuse_mount *fm);
* Setup context ops for submounts
int fuse_init_fs_context_submount(struct fs_context *fsc);
* Shut down the connection (possibly sending DESTROY request).
void fuse_conn_destroy(struct fuse_mount *fm);
/* Drop the connection and free the fuse mount */
void fuse_mount_destroy(struct fuse_mount *fm);
* Add connection to control filesystem
int fuse_ctl_add_conn(struct fuse_conn *fc);
* Remove connection from control filesystem
void fuse_ctl_remove_conn(struct fuse_conn *fc);
* Is file type valid?
int fuse_valid_type(int m);
bool fuse_invalid_attr(struct fuse_attr *attr);
* Is current process allowed to perform filesystem operation?
int fuse_allow_current_process(struct fuse_conn *fc);
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
void fuse_flush_time_update(struct inode *inode);
void fuse_update_ctime(struct inode *inode);
int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask);
void fuse_flush_writepages(struct inode *inode);
void fuse_set_nowrite(struct inode *inode);
void fuse_release_nowrite(struct inode *inode);
* Scan all fuse_mounts belonging to fc to find the first where
* ilookup5() returns a result. Return that result and the
* respective fuse_mount in *fm (unless fm is NULL).
* The caller must hold fc->killsb.
struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
struct fuse_mount **fm);
* File-system tells the kernel to invalidate cache for the given node id.
int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
loff_t offset, loff_t len);
* File-system tells the kernel to invalidate parent attributes and
* the dentry matching parent/name.
* If the child_nodeid is non-zero and:
* - matches the inode number for the dentry matching parent/name,
* - is not a mount point
* - is a file or oan empty directory
* then the dentry is unhashed (d_delete()).
int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
u64 child_nodeid, struct qstr *name);
int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
bool isdir);
* fuse_direct_io() flags
/** If set, it is WRITE; otherwise - READ */
#define FUSE_DIO_WRITE (1 << 0)
/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
#define FUSE_DIO_CUSE (1 << 1)
ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
loff_t *ppos, int flags);
long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
unsigned int flags);
long fuse_ioctl_common(struct file *file, unsigned int cmd,
unsigned long arg, unsigned int flags);
__poll_t fuse_file_poll(struct file *file, poll_table *wait);
int fuse_dev_release(struct inode *inode, struct file *file);
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);
void fuse_set_initialized(struct fuse_conn *fc);
void fuse_unlock_inode(struct inode *inode, bool locked);
bool fuse_lock_inode(struct inode *inode);
int fuse_setxattr(struct inode *inode, const char *name, const void *value,
size_t size, int flags, unsigned int extra_flags);
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 *fuse_acl_xattr_handlers[];
extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
struct posix_acl;
struct posix_acl *fuse_get_acl(struct inode *inode, int type, bool rcu);
int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
/* readdir.c */
int fuse_readdir(struct file *file, struct dir_context *ctx);
* Return the number of bytes in an arguments list
unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
* Get the next unique ID for a request
u64 fuse_get_unique(struct fuse_iqueue *fiq);
void fuse_free_conn(struct fuse_conn *fc);
/* dax.c */
#define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
void fuse_dax_conn_free(struct fuse_conn *fc);
bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
void fuse_dax_inode_init(struct inode *inode);
void fuse_dax_inode_cleanup(struct inode *inode);
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
void fuse_dax_cancel_work(struct fuse_conn *fc);
/* ioctl.c */
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_set(struct user_namespace *mnt_userns,
struct dentry *dentry, struct fileattr *fa);
/* 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);
#endif /* _FS_FUSE_I_H */