i2c: imx: Check the return value from clk_prepare_enable()
[linux-2.6/btrfs-unstable.git] / fs / fuse / fuse_i.h
blob7d2730912667e4514ef109c5ad9ece5584b6770b
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
9 #ifndef _FS_FUSE_I_H
10 #define _FS_FUSE_I_H
12 #include <linux/fuse.h>
13 #include <linux/fs.h>
14 #include <linux/mount.h>
15 #include <linux/wait.h>
16 #include <linux/list.h>
17 #include <linux/spinlock.h>
18 #include <linux/mm.h>
19 #include <linux/backing-dev.h>
20 #include <linux/mutex.h>
21 #include <linux/rwsem.h>
22 #include <linux/rbtree.h>
23 #include <linux/poll.h>
24 #include <linux/workqueue.h>
26 /** Max number of pages that can be used in a single read request */
27 #define FUSE_MAX_PAGES_PER_REQ 32
29 /** Bias for fi->writectr, meaning new writepages must not be sent */
30 #define FUSE_NOWRITE INT_MIN
32 /** It could be as large as PATH_MAX, but would that have any uses? */
33 #define FUSE_NAME_MAX 1024
35 /** Number of dentries for each connection in the control filesystem */
36 #define FUSE_CTL_NUM_DENTRIES 5
38 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
39 module will check permissions based on the file mode. Otherwise no
40 permission checking is done in the kernel */
41 #define FUSE_DEFAULT_PERMISSIONS (1 << 0)
43 /** If the FUSE_ALLOW_OTHER flag is given, then not only the user
44 doing the mount will be allowed to access the filesystem */
45 #define FUSE_ALLOW_OTHER (1 << 1)
47 /** Number of page pointers embedded in fuse_req */
48 #define FUSE_REQ_INLINE_PAGES 1
50 /** List of active connections */
51 extern struct list_head fuse_conn_list;
53 /** Global mutex protecting fuse_conn_list and the control filesystem */
54 extern struct mutex fuse_mutex;
56 /** Module parameters */
57 extern unsigned max_user_bgreq;
58 extern unsigned max_user_congthresh;
60 /* One forget request */
61 struct fuse_forget_link {
62 struct fuse_forget_one forget_one;
63 struct fuse_forget_link *next;
66 /** FUSE inode */
67 struct fuse_inode {
68 /** Inode data */
69 struct inode inode;
71 /** Unique ID, which identifies the inode between userspace
72 * and kernel */
73 u64 nodeid;
75 /** Number of lookups on this inode */
76 u64 nlookup;
78 /** The request used for sending the FORGET message */
79 struct fuse_forget_link *forget;
81 /** Time in jiffies until the file attributes are valid */
82 u64 i_time;
84 /** The sticky bit in inode->i_mode may have been removed, so
85 preserve the original mode */
86 umode_t orig_i_mode;
88 /** 64 bit inode number */
89 u64 orig_ino;
91 /** Version of last attribute change */
92 u64 attr_version;
94 /** Files usable in writepage. Protected by fc->lock */
95 struct list_head write_files;
97 /** Writepages pending on truncate or fsync */
98 struct list_head queued_writes;
100 /** Number of sent writes, a negative bias (FUSE_NOWRITE)
101 * means more writes are blocked */
102 int writectr;
104 /** Waitq for writepage completion */
105 wait_queue_head_t page_waitq;
107 /** List of writepage requestst (pending or sent) */
108 struct list_head writepages;
110 /** Miscellaneous bits describing inode state */
111 unsigned long state;
114 /** FUSE inode state bits */
115 enum {
116 /** Advise readdirplus */
117 FUSE_I_ADVISE_RDPLUS,
118 /** Initialized with readdirplus */
119 FUSE_I_INIT_RDPLUS,
120 /** An operation changing file size is in progress */
121 FUSE_I_SIZE_UNSTABLE,
124 struct fuse_conn;
126 /** FUSE specific file data */
127 struct fuse_file {
128 /** Fuse connection for this file */
129 struct fuse_conn *fc;
131 /** Request reserved for flush and release */
132 struct fuse_req *reserved_req;
134 /** Kernel file handle guaranteed to be unique */
135 u64 kh;
137 /** File handle used by userspace */
138 u64 fh;
140 /** Node id of this file */
141 u64 nodeid;
143 /** Refcount */
144 atomic_t count;
146 /** FOPEN_* flags returned by open */
147 u32 open_flags;
149 /** Entry on inode's write_files list */
150 struct list_head write_entry;
152 /** RB node to be linked on fuse_conn->polled_files */
153 struct rb_node polled_node;
155 /** Wait queue head for poll */
156 wait_queue_head_t poll_wait;
158 /** Has flock been performed on this file? */
159 bool flock:1;
162 /** One input argument of a request */
163 struct fuse_in_arg {
164 unsigned size;
165 const void *value;
168 /** The request input */
169 struct fuse_in {
170 /** The request header */
171 struct fuse_in_header h;
173 /** True if the data for the last argument is in req->pages */
174 unsigned argpages:1;
176 /** Number of arguments */
177 unsigned numargs;
179 /** Array of arguments */
180 struct fuse_in_arg args[3];
183 /** One output argument of a request */
184 struct fuse_arg {
185 unsigned size;
186 void *value;
189 /** The request output */
190 struct fuse_out {
191 /** Header returned from userspace */
192 struct fuse_out_header h;
195 * The following bitfields are not changed during the request
196 * processing
199 /** Last argument is variable length (can be shorter than
200 arg->size) */
201 unsigned argvar:1;
203 /** Last argument is a list of pages to copy data to */
204 unsigned argpages:1;
206 /** Zero partially or not copied pages */
207 unsigned page_zeroing:1;
209 /** Pages may be replaced with new ones */
210 unsigned page_replace:1;
212 /** Number or arguments */
213 unsigned numargs;
215 /** Array of arguments */
216 struct fuse_arg args[3];
219 /** FUSE page descriptor */
220 struct fuse_page_desc {
221 unsigned int length;
222 unsigned int offset;
225 /** The request state */
226 enum fuse_req_state {
227 FUSE_REQ_INIT = 0,
228 FUSE_REQ_PENDING,
229 FUSE_REQ_READING,
230 FUSE_REQ_SENT,
231 FUSE_REQ_WRITING,
232 FUSE_REQ_FINISHED
235 /** The request IO state (for asynchronous processing) */
236 struct fuse_io_priv {
237 int async;
238 spinlock_t lock;
239 unsigned reqs;
240 ssize_t bytes;
241 size_t size;
242 __u64 offset;
243 bool write;
244 int err;
245 struct kiocb *iocb;
246 struct file *file;
250 * A request to the client
252 struct fuse_req {
253 /** This can be on either pending processing or io lists in
254 fuse_conn */
255 struct list_head list;
257 /** Entry on the interrupts list */
258 struct list_head intr_entry;
260 /** refcount */
261 atomic_t count;
263 /** Unique ID for the interrupt request */
264 u64 intr_unique;
267 * The following bitfields are either set once before the
268 * request is queued or setting/clearing them is protected by
269 * fuse_conn->lock
272 /** True if the request has reply */
273 unsigned isreply:1;
275 /** Force sending of the request even if interrupted */
276 unsigned force:1;
278 /** The request was aborted */
279 unsigned aborted:1;
281 /** Request is sent in the background */
282 unsigned background:1;
284 /** The request has been interrupted */
285 unsigned interrupted:1;
287 /** Data is being copied to/from the request */
288 unsigned locked:1;
290 /** Request is counted as "waiting" */
291 unsigned waiting:1;
293 /** State of the request */
294 enum fuse_req_state state;
296 /** The request input */
297 struct fuse_in in;
299 /** The request output */
300 struct fuse_out out;
302 /** Used to wake up the task waiting for completion of request*/
303 wait_queue_head_t waitq;
305 /** Data for asynchronous requests */
306 union {
307 struct {
308 union {
309 struct fuse_release_in in;
310 struct work_struct work;
312 struct path path;
313 } release;
314 struct fuse_init_in init_in;
315 struct fuse_init_out init_out;
316 struct cuse_init_in cuse_init_in;
317 struct {
318 struct fuse_read_in in;
319 u64 attr_ver;
320 } read;
321 struct {
322 struct fuse_write_in in;
323 struct fuse_write_out out;
324 struct fuse_req *next;
325 } write;
326 struct fuse_notify_retrieve_in retrieve_in;
327 struct fuse_lk_in lk_in;
328 } misc;
330 /** page vector */
331 struct page **pages;
333 /** page-descriptor vector */
334 struct fuse_page_desc *page_descs;
336 /** size of the 'pages' array */
337 unsigned max_pages;
339 /** inline page vector */
340 struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
342 /** inline page-descriptor vector */
343 struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
345 /** number of pages in vector */
346 unsigned num_pages;
348 /** File used in the request (or NULL) */
349 struct fuse_file *ff;
351 /** Inode used in the request or NULL */
352 struct inode *inode;
354 /** AIO control block */
355 struct fuse_io_priv *io;
357 /** Link on fi->writepages */
358 struct list_head writepages_entry;
360 /** Request completion callback */
361 void (*end)(struct fuse_conn *, struct fuse_req *);
363 /** Request is stolen from fuse_file->reserved_req */
364 struct file *stolen_file;
368 * A Fuse connection.
370 * This structure is created, when the filesystem is mounted, and is
371 * destroyed, when the client device is closed and the filesystem is
372 * unmounted.
374 struct fuse_conn {
375 /** Lock protecting accessess to members of this structure */
376 spinlock_t lock;
378 /** Refcount */
379 atomic_t count;
381 struct rcu_head rcu;
383 /** The user id for this mount */
384 kuid_t user_id;
386 /** The group id for this mount */
387 kgid_t group_id;
389 /** The fuse mount flags for this mount */
390 unsigned flags;
392 /** Maximum read size */
393 unsigned max_read;
395 /** Maximum write size */
396 unsigned max_write;
398 /** Readers of the connection are waiting on this */
399 wait_queue_head_t waitq;
401 /** The list of pending requests */
402 struct list_head pending;
404 /** The list of requests being processed */
405 struct list_head processing;
407 /** The list of requests under I/O */
408 struct list_head io;
410 /** The next unique kernel file handle */
411 u64 khctr;
413 /** rbtree of fuse_files waiting for poll events indexed by ph */
414 struct rb_root polled_files;
416 /** Maximum number of outstanding background requests */
417 unsigned max_background;
419 /** Number of background requests at which congestion starts */
420 unsigned congestion_threshold;
422 /** Number of requests currently in the background */
423 unsigned num_background;
425 /** Number of background requests currently queued for userspace */
426 unsigned active_background;
428 /** The list of background requests set aside for later queuing */
429 struct list_head bg_queue;
431 /** Pending interrupts */
432 struct list_head interrupts;
434 /** Queue of pending forgets */
435 struct fuse_forget_link forget_list_head;
436 struct fuse_forget_link *forget_list_tail;
438 /** Batching of FORGET requests (positive indicates FORGET batch) */
439 int forget_batch;
441 /** Flag indicating that INIT reply has been received. Allocating
442 * any fuse request will be suspended until the flag is set */
443 int initialized;
445 /** Flag indicating if connection is blocked. This will be
446 the case before the INIT reply is received, and if there
447 are too many outstading backgrounds requests */
448 int blocked;
450 /** waitq for blocked connection */
451 wait_queue_head_t blocked_waitq;
453 /** waitq for reserved requests */
454 wait_queue_head_t reserved_req_waitq;
456 /** The next unique request id */
457 u64 reqctr;
459 /** Connection established, cleared on umount, connection
460 abort and device release */
461 unsigned connected;
463 /** Connection failed (version mismatch). Cannot race with
464 setting other bitfields since it is only set once in INIT
465 reply, before any other request, and never cleared */
466 unsigned conn_error:1;
468 /** Connection successful. Only set in INIT */
469 unsigned conn_init:1;
471 /** Do readpages asynchronously? Only set in INIT */
472 unsigned async_read:1;
474 /** Do not send separate SETATTR request before open(O_TRUNC) */
475 unsigned atomic_o_trunc:1;
477 /** Filesystem supports NFS exporting. Only set in INIT */
478 unsigned export_support:1;
480 /** Set if bdi is valid */
481 unsigned bdi_initialized:1;
484 * The following bitfields are only for optimization purposes
485 * and hence races in setting them will not cause malfunction
488 /** Is fsync not implemented by fs? */
489 unsigned no_fsync:1;
491 /** Is fsyncdir not implemented by fs? */
492 unsigned no_fsyncdir:1;
494 /** Is flush not implemented by fs? */
495 unsigned no_flush:1;
497 /** Is setxattr not implemented by fs? */
498 unsigned no_setxattr:1;
500 /** Is getxattr not implemented by fs? */
501 unsigned no_getxattr:1;
503 /** Is listxattr not implemented by fs? */
504 unsigned no_listxattr:1;
506 /** Is removexattr not implemented by fs? */
507 unsigned no_removexattr:1;
509 /** Are posix file locking primitives not implemented by fs? */
510 unsigned no_lock:1;
512 /** Is access not implemented by fs? */
513 unsigned no_access:1;
515 /** Is create not implemented by fs? */
516 unsigned no_create:1;
518 /** Is interrupt not implemented by fs? */
519 unsigned no_interrupt:1;
521 /** Is bmap not implemented by fs? */
522 unsigned no_bmap:1;
524 /** Is poll not implemented by fs? */
525 unsigned no_poll:1;
527 /** Do multi-page cached writes */
528 unsigned big_writes:1;
530 /** Don't apply umask to creation modes */
531 unsigned dont_mask:1;
533 /** Are BSD file locking primitives not implemented by fs? */
534 unsigned no_flock:1;
536 /** Is fallocate not implemented by fs? */
537 unsigned no_fallocate:1;
539 /** Use enhanced/automatic page cache invalidation. */
540 unsigned auto_inval_data:1;
542 /** Does the filesystem support readdirplus? */
543 unsigned do_readdirplus:1;
545 /** Does the filesystem want adaptive readdirplus? */
546 unsigned readdirplus_auto:1;
548 /** Does the filesystem support asynchronous direct-IO submission? */
549 unsigned async_dio:1;
551 /** The number of requests waiting for completion */
552 atomic_t num_waiting;
554 /** Negotiated minor version */
555 unsigned minor;
557 /** Backing dev info */
558 struct backing_dev_info bdi;
560 /** Entry on the fuse_conn_list */
561 struct list_head entry;
563 /** Device ID from super block */
564 dev_t dev;
566 /** Dentries in the control filesystem */
567 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
569 /** number of dentries used in the above array */
570 int ctl_ndents;
572 /** O_ASYNC requests */
573 struct fasync_struct *fasync;
575 /** Key for lock owner ID scrambling */
576 u32 scramble_key[4];
578 /** Reserved request for the DESTROY message */
579 struct fuse_req *destroy_req;
581 /** Version counter for attribute changes */
582 u64 attr_version;
584 /** Called on final put */
585 void (*release)(struct fuse_conn *);
587 /** Super block for this connection. */
588 struct super_block *sb;
590 /** Read/write semaphore to hold when accessing sb. */
591 struct rw_semaphore killsb;
594 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
596 return sb->s_fs_info;
599 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
601 return get_fuse_conn_super(inode->i_sb);
604 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
606 return container_of(inode, struct fuse_inode, inode);
609 static inline u64 get_node_id(struct inode *inode)
611 return get_fuse_inode(inode)->nodeid;
614 /** Device operations */
615 extern const struct file_operations fuse_dev_operations;
617 extern const struct dentry_operations fuse_dentry_operations;
620 * Inode to nodeid comparison.
622 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
625 * Get a filled in inode
627 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
628 int generation, struct fuse_attr *attr,
629 u64 attr_valid, u64 attr_version);
631 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
632 struct fuse_entry_out *outarg, struct inode **inode);
635 * Send FORGET command
637 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
638 u64 nodeid, u64 nlookup);
640 struct fuse_forget_link *fuse_alloc_forget(void);
642 /* Used by READDIRPLUS */
643 void fuse_force_forget(struct file *file, u64 nodeid);
646 * Initialize READ or READDIR request
648 void fuse_read_fill(struct fuse_req *req, struct file *file,
649 loff_t pos, size_t count, int opcode);
652 * Send OPEN or OPENDIR request
654 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
656 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
657 struct fuse_file *fuse_file_get(struct fuse_file *ff);
658 void fuse_file_free(struct fuse_file *ff);
659 void fuse_finish_open(struct inode *inode, struct file *file);
661 void fuse_sync_release(struct fuse_file *ff, int flags);
664 * Send RELEASE or RELEASEDIR request
666 void fuse_release_common(struct file *file, int opcode);
669 * Send FSYNC or FSYNCDIR request
671 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
672 int datasync, int isdir);
675 * Notify poll wakeup
677 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
678 struct fuse_notify_poll_wakeup_out *outarg);
681 * Initialize file operations on a regular file
683 void fuse_init_file_inode(struct inode *inode);
686 * Initialize inode operations on regular files and special files
688 void fuse_init_common(struct inode *inode);
691 * Initialize inode and file operations on a directory
693 void fuse_init_dir(struct inode *inode);
696 * Initialize inode operations on a symlink
698 void fuse_init_symlink(struct inode *inode);
701 * Change attributes of an inode
703 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
704 u64 attr_valid, u64 attr_version);
706 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
707 u64 attr_valid);
710 * Initialize the client device
712 int fuse_dev_init(void);
715 * Cleanup the client device
717 void fuse_dev_cleanup(void);
719 int fuse_ctl_init(void);
720 void fuse_ctl_cleanup(void);
723 * Allocate a request
725 struct fuse_req *fuse_request_alloc(unsigned npages);
727 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
730 * Free a request
732 void fuse_request_free(struct fuse_req *req);
735 * Get a request, may fail with -ENOMEM,
736 * caller should specify # elements in req->pages[] explicitly
738 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
739 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
740 unsigned npages);
743 * Increment reference count on request
745 void __fuse_get_request(struct fuse_req *req);
748 * Get a request, may fail with -ENOMEM,
749 * useful for callers who doesn't use req->pages[]
751 static inline struct fuse_req *fuse_get_req_nopages(struct fuse_conn *fc)
753 return fuse_get_req(fc, 0);
757 * Gets a requests for a file operation, always succeeds
759 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
760 struct file *file);
763 * Decrement reference count of a request. If count goes to zero free
764 * the request.
766 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
769 * Send a request (synchronous)
771 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
774 * Send a request in the background
776 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
778 void fuse_request_send_background_locked(struct fuse_conn *fc,
779 struct fuse_req *req);
781 /* Abort all requests */
782 void fuse_abort_conn(struct fuse_conn *fc);
785 * Invalidate inode attributes
787 void fuse_invalidate_attr(struct inode *inode);
789 void fuse_invalidate_entry_cache(struct dentry *entry);
792 * Acquire reference to fuse_conn
794 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
796 void fuse_conn_kill(struct fuse_conn *fc);
799 * Initialize fuse_conn
801 void fuse_conn_init(struct fuse_conn *fc);
804 * Release reference to fuse_conn
806 void fuse_conn_put(struct fuse_conn *fc);
809 * Add connection to control filesystem
811 int fuse_ctl_add_conn(struct fuse_conn *fc);
814 * Remove connection from control filesystem
816 void fuse_ctl_remove_conn(struct fuse_conn *fc);
819 * Is file type valid?
821 int fuse_valid_type(int m);
824 * Is current process allowed to perform filesystem operation?
826 int fuse_allow_current_process(struct fuse_conn *fc);
828 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
830 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
831 struct file *file, bool *refreshed);
833 void fuse_flush_writepages(struct inode *inode);
835 void fuse_set_nowrite(struct inode *inode);
836 void fuse_release_nowrite(struct inode *inode);
838 u64 fuse_get_attr_version(struct fuse_conn *fc);
841 * File-system tells the kernel to invalidate cache for the given node id.
843 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
844 loff_t offset, loff_t len);
847 * File-system tells the kernel to invalidate parent attributes and
848 * the dentry matching parent/name.
850 * If the child_nodeid is non-zero and:
851 * - matches the inode number for the dentry matching parent/name,
852 * - is not a mount point
853 * - is a file or oan empty directory
854 * then the dentry is unhashed (d_delete()).
856 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
857 u64 child_nodeid, struct qstr *name);
859 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
860 bool isdir);
861 ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
862 unsigned long nr_segs, size_t count, loff_t *ppos,
863 int write);
864 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
865 unsigned int flags);
866 long fuse_ioctl_common(struct file *file, unsigned int cmd,
867 unsigned long arg, unsigned int flags);
868 unsigned fuse_file_poll(struct file *file, poll_table *wait);
869 int fuse_dev_release(struct inode *inode, struct file *file);
871 void fuse_write_update_size(struct inode *inode, loff_t pos);
873 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
874 struct file *file);
876 #endif /* _FS_FUSE_I_H */