source: trunk/kernel/vfs/vfs.h @ 8

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1/*
2 * vfs.h - Virtual File System definition.
3 *
4 * Author  Mohamed Lamine Karaoui (2015)
5 *         Alain Greiner (2016)
6 *
7 * Copyright (c) UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#ifndef _VFS_H_
26#define _VFS_H_
27
28#include <almos_config.h>
29#include <hal_types.h>
30#include <hal_atomic.h>
31#include <remote_rwlock.h>
32#include <remote_spinlock.h>
33#include <spinlock.h>
34#include <list.h>
35#include <xlist.h>
36#include <slist.h>
37#include <bits.h>
38#include <xhtab.h>
39#include <errno.h>
40#include <metafs.h>
41
42#include <fatfs.h>
43#include <ramfs.h>
44
45/****  Forward declarations  ***/
46
47struct vfs_inode_s;
48struct vfs_dentry_t;
49struct vfs_ctx_t;
50struct vfs_file_ref_s;
51struct vfs_file_s;
52
53struct vfs_inode_op_s;
54struct vfs_dentry_op_s;
55struct vfs_file_op_s;
56struct vfs_ctx_op_s;
57
58struct vfs_lookup_cmd_s;
59struct vfs_lookup_rsp_s;
60
61struct mapper_s;
62struct process_s;
63struct device_s;
64struct vseg_s;
65
66/*********************************************************************************************
67 * This defines the various Flags arguments for an open() or opendir() system call.
68 ********************************************************************************************/
69
70#define VFS_O_APPEND         0x00080000
71#define VFS_O_RDONLY         0x00100000
72#define VFS_O_WRONLY         0x00200000
73#define VFS_O_RDWR           0x00300000
74#define VFS_O_CREATE         0x00400000
75#define VFS_O_EXCL           0x00800000
76#define VFS_O_TRUNC          0x01000000
77#define VFS_O_SYNC               0x08000000
78
79/*********************************************************************************************
80 * This defines the various types of command for an lseek() system call.
81 ********************************************************************************************/
82
83#define VFS_SEEK_SET         0
84#define VFS_SEEK_CUR         1
85#define VFS_SEEK_END         2
86
87/*********************************************************************************************
88 * TODO : the following flags were defined in the vfs-params.h file...
89 *        ... and must be documented. [AG]
90 ********************************************************************************************/
91
92
93//////////////////////////////////////
94///    keep these flags compact    ///
95//////////////////////////////////////
96#define VFS_REGFILE          0x0000000
97#define VFS_DIR              0x0000001
98#define VFS_FIFO             0x0000002
99#define VFS_DEV_CHR          0x0000004
100#define VFS_DEV_BLK          0x0000008
101#define VFS_DEV              0x000000C
102#define VFS_SOCK             0x0000010
103#define VFS_SYMLNK           0x0000020
104//////////////////////////////////////
105
106#define VFS_RD_ONLY          0x0000040
107#define VFS_SYS              0x0000080
108#define VFS_ARCHIVE          0x0000100
109#define VFS_PIPE             0x0000200
110
111#define VFS_IFMT             0x0170000
112#define VFS_IFSOCK           0x0140000
113#define VFS_IFLNK            0x0120000
114#define VFS_IFREG            0x0100000
115#define VFS_IFBLK            0x0060000
116#define VFS_IFDIR            0x0040000
117#define VFS_IFCHR            0x0020000
118#define VFS_IFIFO            0x0010000
119
120#define VFS_ISUID            0x0004000
121#define VFS_ISGID            0x0002000
122#define VFS_ISVTX            0x0001000
123
124#define VFS_IRWXU            0x0000700
125#define VFS_IRUSR            0x0000400
126#define VFS_IWUSR            0x0000200
127#define VFS_IXUSR            0x0000100
128#define VFS_IRWXG            0x0000070
129#define VFS_IRGRP            0x0000040
130#define VFS_IWGRP            0x0000020
131#define VFS_IXGRP            0x0000010
132#define VFS_IRWXO            0x0000007
133#define VFS_IROTH            0x0000004
134#define VFS_IWOTH            0x0000002
135#define VFS_IXOTH            0x0000001
136
137#define VFS_IREAD            VFS_IRUSR
138#define VFS_IWRITE           VFS_IWUSR
139#define VFS_IEXEC            VFS_IXUSR
140
141#define VFS_SET(state,flag)    (state) |= (flag)
142#define VFS_IS(state,flag)     (state) & (flag)
143#define VFS_CLEAR(state,flag)  (state) &= ~(flag)
144
145
146/* Lookup flags */
147#define VFS_LOOKUP_FILE         0x1
148#define VFS_LOOKUP_LAST         0x2
149#define VFS_LOOKUP_OPEN         0x4
150#define VFS_LOOKUP_RESTART      0x8
151#define VFS_LOOKUP_RETRY        0x10
152#define VFS_LOOKUP_PARENT       0x20
153#define VFS_LOOKUP_HELD         0x40
154
155/* Context flags*/
156#define VFS_FS_LOCAL            0x1
157#define VFS_FS_USE_MAPPER       0x2
158
159
160
161
162/******************************************************************************************
163 * This structure define a VFS inode.
164 * It contains an extended pointer on the parent dentry, and (for directory only)
165 * an hash table xhtab refering all children dentries.
166 * The <parent> inode is unique for a directory (not hard links for directories).
167 * For a file, the parent field points to the first dentry who created this inode.
168 * TODO pourquoi deux types de locks ???
169 *****************************************************************************************/
170
171typedef enum 
172{
173    INODE_ATTR_DIRTY  = 0x01,
174    INODE_ATTR_DIR    = 0x02,
175    INODE_ATTR_INLOAD = 0x04,
176    INODE_ATTR_NEW    = 0x08,
177}
178inode_attr_t;
179
180typedef struct vfs_inode_s
181{
182        struct vfs_ctx_s      * ctx;         /*! Rlocal pointer on FS context                */
183    uint32_t                gc;          /*! generation counter                          */
184        uint32_t                inum;        /*! inode identifier (unique in file system)    */
185        uint32_t                attr;        /*! inode attributes (see above)                */
186        uint32_t                size;        /*! number of bytes                             */
187        uint32_t                links;       /*! number of alias dentry                      */
188        uid_t                   uid;         /*! user owner identifier                       */
189        gid_t                   gid;         /*! group owner identifier                      */
190    uint32_t                mode;        /*! access mode                                 */
191        uint32_t                    refcount;    /*! reference counter (all pointers)            */
192        xptr_t                  parent_xp;   /*! extended pointer on parent dentry           */
193        xhtab_t                 children;    /*! embedded htab of dir entries (for dir type) */
194        remote_rwlock_t         size_lock;   /*! protect size field modifications            */
195        remote_spinlock_t       main_lock;   /*! protect other fields (including children)   */
196        xlist_entry_t           xlist;       /*! member of set of inodes in same cluster     */
197        xlist_entry_t           wait_root;   /*! root of threads waiting on this inode       */
198        struct vfs_inode_op_s * op;          /*! TODO ???                                    */
199        struct mapper_s       * mapper;      /*! associated file cache                       */
200        void                  * extend;      /*! FS specific inode extension                 */
201}
202vfs_inode_t;
203
204/******************************************************************************************
205 * This structure defines a directory entry.
206 * A dentry contains the name of a remote file/dir, an extended pointer on the
207 * inode representing this file/dir, and a local pointer on the inode representing
208 * the parent directory.
209 *****************************************************************************************/
210
211typedef struct vfs_dentry_s
212{
213    struct vfs_ctx_s       * ctx;        /*! local pointer on FS context                 */
214        char                     name[CONFIG_VFS_MAX_NAME_LENGTH];
215        uint32_t                 length;     /*! name length (bytes)                         */
216        uint32_t                 refcount;   /*! reference counter (all pointers)            */
217    struct vfs_inode_s     * parent;     /*! local pointer on parent inode               */
218    xptr_t                   child_xp;   /*! extended pointer on child inode             */
219    xlist_entry_t            xlist;      /*! member of xlist of dentries with same key   */
220        struct vfs_dentry_op_s * op;         /*! TODO                                        */
221        void                   * extend;     /*! FS specific extension                       */
222}
223vfs_dentry_t;
224
225/******************************************************************************************
226 * This structure describes an open file/directory for a given process.
227 * It is not replicated, and is dynamically allocated in the cluster that contains
228 * the inode, when a thread makes an open() or opendir() system call.
229 *****************************************************************************************/
230
231typedef enum   
232{
233    VFS_FD_NORMAL,                      /*! file or directory                            */
234    VFS_FD_PIPE,                        /*! POSIX pipe                                   */
235    VFS_FD_SOCKET,                      /*! POSIX socket                                 */
236    VFS_FD_DEV,                         /*! peripheral channel                           */
237}
238vfs_fd_type_t;
239
240typedef enum
241{
242    VFS_ATTR_READ_ENABLE  = 0x01,       /*! read access possible                         */
243    VFS_ATTR_WRITE_ENABLE = 0x02,       /*! write access possible                        */
244    VFS_ATTR_APPEND       = 0x04,       /*! append on each write                         */
245    VFS_ATTR_CLOSE_EXEC   = 0x08,       /*! close file on exec                           */
246    VFS_ATTR_SYNC         = 0x10,       /*! synchronise FS on each write                 */
247    VFS_ATTR_IS_DIR       = 0x20,       /*! this is a directory                          */
248}
249vfs_fd_attr_t;
250
251typedef struct vfs_file_s
252{
253        uint32_t                gc;         /*! generation counter                           */
254        uint32_t                type;       /*! see above                                    */
255        uint32_t                attr;       /*! see above                                    */
256        uint32_t                offset;     /*! seek position in file                        */
257        uint32_t                refcount;   /*! all pointers on this file                    */
258        remote_rwlock_t       lock;       /*! protect offset modifications                 */
259        struct mapper_s       * mapper;     /*! associated file cache                        */
260        struct vfs_inode_s    * inode;      /*! local pointer on associated inode            */
261        struct vfs_ctx_s      * ctx;        /*! file system features                         */
262        struct vfs_file_op_s  * op;         /*! local set of function pointers               */
263}
264vfs_file_t;
265
266/******************************************************************************************
267 * This structure defines informations common to all inodes and dentries
268 * of a given file system. As it is declared a global variable in the kdata segment,
269 * it is replicated in all clusters and handled as private by each OS intance.
270 *****************************************************************************************/
271
272typedef enum
273{
274        FS_TYPE_SYSFS = 0,
275        FS_TYPE_DEVFS = 1,
276        FS_TYPE_FATFS = 2,
277        FS_TYPE_RAMFS = 3,
278 
279        FS_TYPES_NR   = 4,
280}
281vfs_types_t;
282
283typedef struct vfs_ctx_s
284{
285        uint32_t                      type;          /*! File System type                        */
286        uint32_t                      flags;         /*! TODO ???                                */
287        uint32_t                  count;         /*! number of clusters                      */
288        uint32_t                  blksize;       /*! cluster size                            */
289    xptr_t                    ioc_xp;        /*! extended pointer on IOC device          */
290        xptr_t                    root_xp;       /*! extended pointer on root inode          */
291
292    spinlock_t                lock;          /*! lock protecting inum allocator          */
293        BITMAP( inum , CONFIG_VFS_MAX_INODES );  /*! inum allocator                          */ 
294
295    void                    * extend;        /*! FS specific context extension           */
296}
297vfs_ctx_t;
298
299/******************************************************************************************
300 * This structure define the informations associated to a given file descriptor,
301 * that are returned by the vfs_stat() function.
302 *****************************************************************************************/
303
304typedef struct vfs_stat_s
305{
306        uint32_t    dev;        /*! ID of device containing file                             */
307        uint32_t    ino;        /*! inode number                                             */
308        uint32_t    mode;       /*! protection                                               */
309        uint32_t    nlink;      /*! number of hard links                                     */
310        uint32_t    uid;        /*! user ID of owner                                         */
311        uint32_t    gid;        /*! group ID of owner                                        */
312        uint32_t    rdev;       /*! device ID (if special file)                              */
313        uint64_t    size;       /*! total size, in bytes                                     */
314        uint32_t    blksize;    /*! blocksize for file system I/O                            */
315        uint32_t    blocks;     /*! number of 512B blocks allocated                          */
316        uint64_t    atime;      /*! time of last access                                      */
317        uint64_t    mtime;      /*! time of last modification                                */
318        uint64_t    ctime;      /*! time of last status change                               */
319}
320vfs_stat_t;
321
322
323
324
325
326
327/******************************************************************************************
328 * This structure defines the set of operations that can be done on a VFS context.
329 * TODO A quoi cela sert-il ? [AG]
330 *****************************************************************************************/
331
332typedef error_t (vfs_create_context_t)  ( vfs_ctx_t * context );
333typedef error_t (vfs_destroy_context_t) ( vfs_ctx_t * context );
334typedef error_t (vfs_read_root_t)       ( vfs_ctx_t * context , vfs_inode_t * root );
335typedef error_t (vfs_reply_root_t)      ( vfs_ctx_t * context , vfs_inode_t * root );
336typedef error_t (vfs_write_root_t)      ( vfs_ctx_t * context , vfs_inode_t * root );
337
338struct vfs_ctx_op_s
339{
340        vfs_create_context_t  * create;      /*! allocate memory and initialize a context   */
341        vfs_destroy_context_t * destroy;     /*! release memory allocated to a context      */
342        vfs_read_root_t       * read_root;   /*! TODO                                       */
343        vfs_reply_root_t      * repli_root;  /*! TODO                                       */
344        vfs_write_root_t      * write_root;  /*! TODO                                       */
345}
346vfs_ctx_op_t;
347
348/******************************************************************************************
349 * This structure defines the set of operations that can be done on a VFS inode.
350 * TODO A quoi cela sert-il ? [AG]
351 *****************************************************************************************/
352
353typedef error_t (vfs_init_inode_t)    ( vfs_inode_t * inode );
354typedef error_t (vfs_create_inode_t)  ( vfs_inode_t * parent , vfs_dentry_t  * dentry );
355typedef error_t (vfs_lookup_inode_t)  ( vfs_inode_t * parent , vfs_dentry_t  * dentry );
356typedef error_t (vfs_write_inode_t)   ( vfs_inode_t * inode );
357typedef error_t (vfs_release_inode_t) ( vfs_inode_t * inode );
358typedef error_t (vfs_unlink_inode_t)  ( vfs_inode_t * parent , vfs_dentry_t  * dentry , uint32_t flags );
359typedef error_t (vfs_stat_inode_t)    ( vfs_inode_t * inode );
360typedef error_t (vfs_trunc_inode_t)   ( vfs_inode_t * inode );
361typedef error_t (vfs_delete_inode_t)  ( vfs_inode_t * inode );
362
363typedef struct vfs_inode_op_s
364{
365        vfs_init_inode_t    * init;     /*! initialise inode from scratch                    */
366        vfs_create_inode_t  * create;   /*! allocate memory for one inode                    */
367        vfs_lookup_inode_t  * lookup;   /*! get one directory entry by name                  */ 
368        vfs_write_inode_t   * write;    /*! update the device from the inode                 */
369        vfs_release_inode_t * release;  /*! reset one inode and release associated objects   */
370        vfs_unlink_inode_t  * unlink;   /*! unlink a directory entry from parent inode       */
371        vfs_delete_inode_t  * delete;   /*! release memory allocated to inode when count = 0 */
372        vfs_stat_inode_t    * stat;     /*! TODO                                             */
373        vfs_trunc_inode_t   * trunc;    /*! change the size of a file                        */
374}
375vfs_inode_op_t;
376
377/******************************************************************************************
378 * This structure defines the set of operations that can be done on a VFS dentry.
379 * TODO A quoi cela sert-il ? [AG]
380 *****************************************************************************************/
381
382typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
383
384typedef struct vfs_dentry_op_s
385{
386        vfs_compare_dentry_t * compare;
387}
388vfs_dentry_op_t;
389
390/******************************************************************************************
391 * This structure defines the set of operations that can be done on a VFS file. 
392 * TODO A quoi cela sert-il ? [AG]
393 *****************************************************************************************/
394
395typedef error_t (vfs_open_file_t)    ( vfs_file_t * file , void * priv );
396typedef error_t (vfs_read_file_t)    ( vfs_file_t * file , char * buffer );
397typedef error_t (vfs_write_file_t)   ( vfs_file_t * file , char * buffer );
398typedef error_t (vfs_lseek_file_t)   ( vfs_file_t * file );
399typedef error_t (vfs_close_file_t)   ( vfs_file_t * file );
400typedef error_t (vfs_release_file_t) ( vfs_file_t * file );
401typedef error_t (vfs_read_dir_t)     ( vfs_file_t * file );
402typedef error_t (vfs_mmap_file_t)    ( vfs_file_t * file , struct vseg_s * vseg );
403typedef error_t (vfs_munmap_file_t)  ( vfs_file_t * file , struct vseg_s * vseg );
404
405typedef struct vfs_file_op_s
406{
407        vfs_open_file_t    * open;
408        vfs_read_file_t    * read;
409        vfs_write_file_t   * write;
410        vfs_lseek_file_t   * lseek;
411        vfs_read_dir_t     * readdir;
412        vfs_close_file_t   * close;
413        vfs_release_file_t * release;
414        vfs_mmap_file_t    * mmap;
415        vfs_munmap_file_t  * munmap;
416}
417vfs_file_op_t;
418
419
420
421
422
423
424/*****************************************************************************************/
425/******************** VFS global functions ***********************************************/
426/*****************************************************************************************/ 
427
428/******************************************************************************************
429 * This function initializes the Virtual File System.     
430 *****************************************************************************************/
431void vfs_init();
432
433/******************************************************************************************
434 * This function mount a given file system type for a given process.     
435 *****************************************************************************************/
436error_t vfs_mount_fs_root( struct device_s  * device,
437                                       uint32_t           fs_type,
438                                       struct process_s * process );
439
440
441/*****************************************************************************************/
442/******************* FS Context related functions ****************************************/
443/*****************************************************************************************/
444
445/******************************************************************************************
446 * This function allocates an inode identifier from the local cluster inum allocator.
447 * The inum respects a fixed format:
448 * - the 16 MSB bits contain the cluster identifier : cxy
449 * - the 16 LSB bits contains the local inode identifier  : lid
450 ******************************************************************************************
451 * @ ctx      : local pointer on file system context.
452 * @ inum     : [ou] buffer for allocated inode identifier.
453 * @ return 0 if success / return non-zero if error.
454 *****************************************************************************************/
455error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
456                            uint32_t  * inum );
457
458/******************************************************************************************
459 * This function release an inode identifier.                                 
460 ******************************************************************************************
461 * @ ctx      : local pointer on file system context.
462 * @ inum     : released inode identifier.
463 *****************************************************************************************/
464void vfs_ctx_inum_release( vfs_ctx_t * ctx,
465                           uint32_t    inum );
466
467
468
469/*****************************************************************************************/
470/************************ File Descriptor related functions ******************************/
471/*****************************************************************************************/
472
473/******************************************************************************************
474 * This function allocates memory and initializes a new local file descriptor.
475 * It must be executed in the owner cluster containing the inode.
476 * If the client thread is not running in the owner cluster, it must use the
477 * rpc_vfs_file_create_client() function.
478 ******************************************************************************************
479 * @ inode_xp : extended pointer on associated inode.
480 * @ type     : file descriptor type.
481 * @ attr     : file descriptor attributes.
482 * @ file_xp  : [out] buffer for extended pointer on created file descriptor.
483 * @ return 0 if success / return ENOMEM if error.
484 *****************************************************************************************/
485error_t vfs_file_create( xptr_t     inode_xp,
486                         uint32_t   type,
487                         uint32_t   attr,
488                         xptr_t   * file_xp ); 
489
490/******************************************************************************************
491 * This function releases memory allocated to a local file descriptor.
492 * It must be executed by a thread running in the cluster containing the inode,
493 * and the file refcount must be zero.
494 * If the client thread is not running in the owner cluster, it must use the
495 * rpc_vfs_file_destroy_client() function.
496 ******************************************************************************************
497 * @ file_xp  : extended pointer on file descriptor.
498 *****************************************************************************************/
499void vfs_file_destroy( xptr_t  file_xp ); 
500
501
502/******************************************************************************************
503 * These functions increment (resp. decrement) the count field in a remote file
504 * descriptor, using a remote_atomic access.
505 *****************************************************************************************/
506void vfs_file_count_up  ( xptr_t   file_xp );
507void vfs_file_count_down( xptr_t   file_xp );
508
509
510
511/*****************************************************************************************/
512/********************* Inode related functions *******************************************/
513/*****************************************************************************************/
514
515/******************************************************************************************
516 * This function allocates memory from local cluster for an inode descriptor and the
517 * associated mapper. It initialise these descriptors from arguments values.
518 * The parent dentry must have been previously created.
519 * If the client thread is not running in the cluster containing this inode,
520 * it must use the rpc_vfs_inode_create_client() function.
521 ******************************************************************************************
522 * @ dentry_xp  : extended pointer on associated dentry (in parent inode cluster).
523 * @ type       : file system type.
524 * @ attr       : inode attributes.
525 * @ mode       : inode access mode.
526 * @ uid        : user owner ID.
527 * @ gid        : group owner ID.
528 * @ inode_xp   : [out] buffer for extended pointer on created inode.
529 * # return 0 if success / return ENOMEM or EINVAL if error.
530 *****************************************************************************************/
531error_t vfs_inode_create( xptr_t      dentry_xp,
532                          uint32_t    type,
533                          uint32_t    attr,
534                          uint32_t    mode,
535                          uid_t       uid,
536                          gid_t       gid,
537                          xptr_t    * inode_xp );
538
539/******************************************************************************************
540 * This function releases memory allocated to an inode descriptor.
541 * It must be executed by a thread running in the cluster containing the inode,
542 * and the inode refcount must be zero.
543 * If the client thread is not running in the owner cluster, it must use the
544 * rpc_vfs_inode_destroy_client() function.
545 ******************************************************************************************
546 * @ inode  : local pointer on inode descriptor.
547 *****************************************************************************************/
548void vfs_inode_destroy( vfs_inode_t *  inode ); 
549
550/******************************************************************************************
551 * This function atomically increment the inode refcount.
552 * It can be called by any thread running in any cluster.
553 *****************************************************************************************/
554void vfs_inode_remote_up( xptr_t  inode_xp );
555
556/******************************************************************************************
557 * This function atomically decrement the inode refcount.
558 * It can be called by any thread running in any cluster.
559 *****************************************************************************************/
560void vfs_inode_remote_down( xptr_t  inode_xp );
561
562/******************************************************************************************
563 * This function returns the <size> of a file/dir from a remote inode,
564 * taking the remote_rwlock protecting <size> in READ_MODE.
565 *****************************************************************************************
566 * @ inode_xp  : extended pointer on the remote inode.
567 * @ return the current size.
568 *****************************************************************************************/
569uint32_t vfs_inode_get_size( xptr_t inode_xp );
570
571/******************************************************************************************
572 * This function set the <size> of a file/dir to a remote inode,
573 * taking the remote_rwlock protecting <size> in WRITE_MODE.
574 *****************************************************************************************
575 * @ inode_xp  : extended pointer on the remote inode.
576 * @ size      : value to be written.
577 *****************************************************************************************/
578void vfs_inode_set_size( xptr_t   inode_xp,
579                         uint32_t size );
580
581/******************************************************************************************
582 * This function takes the main lock of a remote inode.
583 * This lock protect all inode fiels, including the children dentries.
584 *****************************************************************************************
585 * @ inode_xp  : extended pointer on the remote inode.
586 *****************************************************************************************/
587void vfs_inode_remote_lock( xptr_t inode_xp );
588
589/******************************************************************************************
590 * This function releases the main lock of a remote inode.
591 * This lock protect all inode fiels, including the children dentries.
592 *****************************************************************************************
593 * @ inode_xp  : extended pointer on the remote inode.
594 *****************************************************************************************/
595void vfs_inode_remote_unlock( xptr_t inode_xp );
596
597
598
599
600/******************************************************************************************
601 * This function TODO                                                         
602 *****************************************************************************************/
603error_t vfs_inode_hold( vfs_inode_t * inode,
604                        uint32_t      gc );
605
606/******************************************************************************************
607 * This function TODO                                                         
608 *****************************************************************************************/
609error_t vfs_inode_trunc( vfs_inode_t * inode );
610
611/******************************************************************************************
612 * This function TODO                                                         
613 *****************************************************************************************/
614error_t vfs_inode_link( vfs_inode_t * inode,
615                        uint32_t      igc );
616
617/******************************************************************************************
618 * This function TODO                                                         
619 *****************************************************************************************/
620error_t vfs_inode_unlink( vfs_inode_t * inode );
621
622/******************************************************************************************
623 * This function TODO                                                         
624 *****************************************************************************************/
625error_t vfs_inode_stat( vfs_inode_t * inode,
626                        uint32_t      inum );
627
628/******************************************************************************************
629 * This function TODO                                                         
630 *****************************************************************************************/
631error_t vfs_icache_del( vfs_inode_t * inode );
632
633
634/******************************************************************************************
635 * This function TODO  Pourquoi 2 arguments ?
636 *****************************************************************************************/
637error_t vfs_stat_inode( vfs_inode_t * inode,
638                        uint32_t      inum );
639
640
641/*****************************************************************************************/
642/***************** Dentry related functions **********************************************/
643/*****************************************************************************************/
644
645/******************************************************************************************
646 * This function allocates memory from local cluster for a dentry descriptor,
647 * initialises it from  arguments values, and returns the extended pointer on dentry.
648 * The inode field is not initialized, because the inode does not exist yet.
649 * If the client thread is not running in the target cluster for this inode,
650 * it must use the rpc_dentry_create_client() function.
651 ******************************************************************************************
652 * @ type       : file system type.
653 * @ name       : directory entry file/dir name.
654 * @ parent     : local pointer on parent inode.
655 * @ dentry_xp  : [out] buffer for extended pointer on created inode.
656 * @ return 0 if success / return ENOMEM or EINVAL if error.
657 *****************************************************************************************/
658error_t vfs_dentry_create( uint32_t      type,
659                           char        * name,
660                           vfs_inode_t * parent,
661                           xptr_t      * dentry_xp );
662 
663/******************************************************************************************
664 * This function releases memory allocated to a dentry descriptor.
665 * It must be executed by a thread running in the cluster containing the dentry,
666 * and the dentry refcount must be zero.
667 * If the client thread is not running in the owner cluster, it must use the
668 * rpc_dentry_destroy_client() function.
669 ******************************************************************************************
670 * @ dentry  : local pointer on dentry descriptor.
671 *****************************************************************************************/
672void vfs_dentry_destroy( vfs_dentry_t *  dentry ); 
673
674/******************************************************************************************
675 * This function atomically increment the dentry refcount.                               
676 * It can be called by any thread running in any cluster.
677 *****************************************************************************************/
678void vfs_dentry_remote_up( xptr_t dentry_xp );
679
680/******************************************************************************************
681 * This function atomically decrement the dentry refcount.                               
682 * It can be called by any thread running in any cluster.
683 *****************************************************************************************/
684void vfs_dentry_remote_down( xptr_t dentry_xp );
685
686
687/*****************************************************************************************/
688/*                 Inode-Tree related functions                                          */ 
689/*****************************************************************************************/ 
690
691/******************************************************************************************
692 * This function returns in a kernel buffer allocated by the caller function,
693 * the pathname of a file/dir identified by an extended pointer on the inode.
694 * It traverse the Inode Tree from the target node to the root.
695 * It can be called by any thread running in any cluster.
696 ******************************************************************************************
697 * @ inode_xp    : pointer on inode descriptor.
698 * @ buffer      : kernel buffer for pathname (must be allocated by caller).
699 * @ size        : max number of characters in buffer.
700 * @ return 0 if success / return EINVAL if buffer too small.
701 *****************************************************************************************/
702error_t vfs_get_path( xptr_t    inode_xp,
703                      char    * buffer,
704                      uint32_t  max_size );
705
706/******************************************************************************************
707 * This function takes a pathname (absolute or relative to cwd) and returns an extended
708 * pointer on the associated inode, and an extended pointer on the inode context.
709 * If a given name in the path is not found in the inode tree, it try to load the missing
710 * dentry/inode couple, from informations found in the parent directory.
711 * If this directory entry does not exist on device, it returns an error.
712 ******************************************************************************************
713 * @ cwd_xp     : extended pointer on current directory (for relative path).
714 * @ pathname   : path in kernel space (can be relative or absolute).
715 * @ client_uid : client thread user ID (for checking).
716 * @ client_gid : client thread group ID (for checking).
717 * @ inode_xp   : [out] buffer for extended pointer on inode.
718 * @ ctx_xp     : [out] buffer for extended pointer on inode context.
719 * @ return 0 if success / ENOENT if inode not found / EACCES if permissopn denied
720 *****************************************************************************************/
721error_t vfs_lookup( xptr_t       cwd_xp,
722                    char       * pathname,
723                    uint32_t     client_uid,
724                    uint32_t     client_gid,
725                                        xptr_t     * inode_xp,
726                    xptr_t     * ctx_xp );
727
728/******************************************************************************************
729 * This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
730 * It can be executed by any thread running in any cluster, as this function
731 * uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
732 * - The dentry is created in the cluster containing the existing <parent_xp> inode.
733 * - the child inode and its associated mapper are created in a randomly selected cluster.
734 * - The dentry name is defined by the <name> argument.
735 ******************************************************************************************
736 * @ type       : new inode type
737 * @ parent_xp  : extended pointer on parent inode.
738 * @ name       : new directory entry name.
739 * @ child_xp   : [out] buffer for extended pointer on child inode.
740 * @ return 0 if success / ENOENT if entry not found in parent directory
741 *****************************************************************************************/
742error_t vfs_add_child_in_parent( uint32_t type,
743                                 xptr_t   parent_xp,
744                                 char   * name,   
745                                 xptr_t * child_xp );
746
747/******************************************************************************************
748 * TODO
749 ******************************************************************************************
750 * @ child_xp   : extended pointer on removed inode.
751 *****************************************************************************************/
752error_t vfs_remove_child_from_parent( xptr_t child_xp );
753
754/*****************************************************************************************/
755/************************ File related functions *****************************************/
756/*****************************************************************************************/
757
758/******************************************************************************************
759 * This function allocates a vfs_file_t structure in the cluster containing the inode
760 * associated to the requested file, initializes it, and returns an extended pointer
761 * on this remote open file descriptor.
762 * The pathname can be relative to current directory or absolute.
763 * If the inode does not exist in the inode cache, it try to find file on the mounted
764 * device, and creates an inode on a pseudo randomly selected cluster if found.
765 * It the requested file does not exist on device, it creates a new inode if the
766 * O_CREAT flag is set and return an error otherwise.
767 ******************************************************************************************
768 * @ cwd_xp    : extended pointer on current directory file descriptor (for relative path).
769 * @ path      : file pathname (absolute or relative to current directory).
770 * @ flags     : O_RDONLY, O_WRONLY, O_CREATE etc...
771 * @ file_xp   : [out] buffer for extended pointer on created remote file descriptor.
772 * @ return 0 if success / return non-zero if error.
773 *****************************************************************************************/
774error_t vfs_open( xptr_t     cwd_xp,
775                          char     * path,
776                          uint32_t   flags,
777                          xptr_t   * file_xp );
778
779/******************************************************************************************
780 * This function moves <size> bytes from the file identified by the open file descriptor
781 * <file_xp> to the local kernel <buffer> , taken into account the offset in <file_xp>.
782 ******************************************************************************************
783 * @ file_xp   : extended pointer on the remote open file descriptor.
784 * @ buffer    : local pointer on destination kernel buffer.
785 * @ size      : requested number of bytes from offset.
786 * @ returns number of bytes actually transfered / 0 if EOF / -1 if error.
787 *****************************************************************************************/
788uint32_t vfs_read( xptr_t   file_xp, 
789                   void   * buffer,
790                   uint32_t size );
791
792/******************************************************************************************
793 * This function moves <size> bytes from the local kernel <buffer> to the open file
794 * descriptor <file_xp>, taken into account the offset defined in <file_xp>.
795 ******************************************************************************************
796 * @ file_xp   : extended pointer on the remote open file descriptor.
797 * @ buffer    : local pointer on source kernel buffer.
798 * @ size      : requested number of bytes to be written from offset.
799 * @ returns number of bytes actually transfered / -1 if error.
800 *****************************************************************************************/
801uint32_t vfs_write( xptr_t   file_xp,
802                    void   * buffer,
803                    uint32_t size );
804
805/******************************************************************************************
806 * This function set a new value in the offset of the open file descriptor <file_xp>.
807 * This value depends on the <whence> argument:
808 * - if VFS_SEEK_SET, new value is <offset>
809 * - if VFS_SEEK_CUR, new value is current_offset + <offset>
810 * - if VFS_SEEK_END, new value is file_size + <offset>
811 ******************************************************************************************
812 * @ file_xp   : extended pointer on the remote open file descriptor.
813 * @ offset    : local pointer on source kernel buffer.
814 * @ whence    : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
815 * @ new_offset : [out] buffer for new offset value.
816 * @ returns 0 if success / -1 if error.
817 *****************************************************************************************/
818error_t vfs_lseek( xptr_t     file_xp,
819                   uint32_t   offset,
820                   uint32_t   whence, 
821                   uint32_t * new_offset );
822
823/******************************************************************************************
824 * This function close an open file descriptor.                             
825 ******************************************************************************************
826 * @ file_xp     : extended pointer on the file descriptor.
827 * @ refcount    : number of references after close.
828 * @ return 0 if success / return -1 if error
829 *****************************************************************************************/
830error_t vfs_close( xptr_t     file_xp, 
831                   uint32_t * refcount );
832
833/******************************************************************************************
834 * This function remove from the file system a directory entry identified by its pathname.
835 * The pathname can be relative to current directory or absolute.
836 ******************************************************************************************
837 * @ cwd_xp   : extended pointer on the current directory file descriptor.
838 * @ path     : pathname (absolute or relative to current directory).
839 *****************************************************************************************/
840error_t vfs_unlink( xptr_t   cwd_xp,
841                    char   * path );
842
843/******************************************************************************************
844 * This function returns in the <ustat> structure various informations on the file TODO
845 *****************************************************************************************/
846error_t vfs_stat( xptr_t       file_xp,
847                  vfs_stat_t * ustat );
848
849
850
851
852/*****************************************************************************************/
853/************************ Directory related functions ************************************/
854/*****************************************************************************************/
855
856/******************************************************************************************
857 * This function TODO                                                         
858 *****************************************************************************************/
859error_t vfs_opendir( xptr_t      cwd_xp,
860                     char      * path,
861                     uint32_t    flags,
862                     xptr_t      file_xp );
863
864/******************************************************************************************
865 * This function TODO                                                         
866 *    fat32_readdir need cleaning
867 *****************************************************************************************/
868error_t vfs_readdir( xptr_t            file_xp,
869                     char            * path );
870
871/******************************************************************************************
872 * This function TODO                                                         
873 *****************************************************************************************/
874error_t vfs_mkdir( xptr_t            file_xp,
875                   char            * path,
876                   uint32_t          mode );
877
878/******************************************************************************************
879 * This function remove a directory from the file system.
880 *****************************************************************************************/
881error_t vfs_rmdir( xptr_t            file_xp,
882                   char            * path );
883
884/******************************************************************************************
885 * This function TODO                                                         
886 *****************************************************************************************/
887error_t vfs_chdir( char            * pathname,
888                   xptr_t            cwd_xp );
889
890/******************************************************************************************
891 * This function TODO                                                         
892 *****************************************************************************************/
893error_t vfs_chmod( char            * pathname,
894                   vfs_file_t      * cwd,
895                   uint32_t          mode );
896
897/******************************************************************************************
898 * This function TODO                                                         
899 *****************************************************************************************/
900error_t vfs_closedir( xptr_t       file_xp,
901                      uint32_t   * refcount );
902
903
904
905
906/*****************************************************************************************/
907/*******************  Pipe related functions *********************************************/
908/*****************************************************************************************/
909
910/******************************************************************************************
911 * This function TODO ???                                                         
912 *****************************************************************************************/
913error_t vfs_pipe( xptr_t pipefd[2] );
914
915/******************************************************************************************
916 * This function TODO                                                         
917 *****************************************************************************************/
918error_t vfs_mkfifo( xptr_t            cwd_xp,
919                    char            * path,
920                    uint32_t          mode );
921
922
923
924
925#endif  /* _VFS_H_ */
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