source: trunk/kernel/vfs/vfs.h @ 239

Last change on this file since 239 was 239, checked in by alain, 5 years ago

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1/*
2 * vfs.h - Virtual File System definition.
3 *
4 * Author  Mohamed Lamine Karaoui (2014,2015)
5 *         Alain Greiner (2016,2017)
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 <kernel_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#include <devfs.h>
45
46/****  Forward declarations  ***/
47
48struct vfs_inode_s;
49struct vfs_dentry_t;
50struct vfs_ctx_t;
51struct vfs_file_ref_s;
52struct vfs_file_s;
53
54struct vfs_inode_op_s;
55struct vfs_dentry_op_s;
56struct vfs_file_op_s;
57struct vfs_ctx_op_s;
58
59struct vfs_lookup_cmd_s;
60struct vfs_lookup_rsp_s;
61
62struct mapper_s;
63struct process_s;
64struct device_s;
65struct vseg_s;
66struct page_s;
67
68
69/******************************************************************************************
70 * These flags are used to define the working mode of the vfs_lookup() function. 
71 *****************************************************************************************/
72
73#define VFS_LOOKUP_DIR      0x01     /* the searched inode is a directory                */
74#define VFS_LOOKUP_OPEN         0x02     /* the search is for an open/opendir                */
75#define VFS_LOOKUP_PARENT       0x04     /* return the parent inode (not the inode itself)   */
76#define VFS_LOOKUP_CREATE   0x10     /* file must be created if missing                  */
77#define VFS_LOOKUP_EXCL     0x20     /* file cannot previously exist                     */   
78
79/******************************************************************************************
80 * This define the masks for the POSIX access rights to inodes
81 *****************************************************************************************/
82
83#define VFS_ISUID                0x0004000
84#define VFS_ISGID                0x0002000
85#define VFS_ISVTX                0x0001000
86
87#define VFS_IRWXU            0x0000700
88#define VFS_IRUSR            0x0000400
89#define VFS_IWUSR            0x0000200
90#define VFS_IXUSR            0x0000100
91
92#define VFS_IRWXG            0x0000070
93#define VFS_IRGRP            0x0000040
94#define VFS_IWGRP            0x0000020
95#define VFS_IXGRP            0x0000010
96
97#define VFS_IRWXO            0x0000007
98#define VFS_IROTH            0x0000004
99#define VFS_IWOTH            0x0000002
100#define VFS_IXOTH            0x0000001
101
102#define VFS_IREAD            VFS_IRUSR
103#define VFS_IWRITE           VFS_IWUSR
104#define VFS_IEXEC            VFS_IXUSR
105
106
107/******************************************************************************************
108 * This structure defines informations common to all inodes and dentries
109 * of a given file system. As it is declared a global variable in the kdata segment,
110 * it is replicated in all clusters and handled as private by each OS intance.
111 *****************************************************************************************/
112
113typedef enum
114{
115        FS_TYPE_DEVFS = 0,
116        FS_TYPE_FATFS = 1,
117        FS_TYPE_RAMFS = 2,
118 
119        FS_TYPES_NR   = 3,
120}
121vfs_fs_type_t;
122
123typedef enum
124{
125    CTX_ATTR_READ_ONLY    = 0x01,            /*! write access prohibited                 */
126    CTX_ATTR_SYNC         = 0x10,            /*! synchronise FS on each write            */
127}
128vfs_ctx_attr_t;
129
130typedef struct vfs_ctx_s
131{
132        vfs_fs_type_t  type;                     /*! File System type                        */
133        uint32_t           attr;                     /*! global attributes for all files in FS   */
134        uint32_t       total_clusters;           /*! total number of clusters on device      */
135        uint32_t       cluster_size;             /*! cluster size on device (bytes)          */
136        xptr_t         vfs_root_xp;              /*! extended pointer on VFS root inode      */
137    spinlock_t     lock;                     /*! lock protecting inum allocator          */
138    uint32_t       bitmap[BITMAP_SIZE(CONFIG_VFS_MAX_INODES)];  /* inum allocator        */
139    void         * extend;                   /*! FS specific context extension           */
140}
141vfs_ctx_t;
142
143/******************************************************************************************
144 * This structure define a VFS inode.
145 * It contains an extended pointer on the parent dentry, and (for directory only)
146 * an hash table xhtab refering all children dentries.
147 * The <parent> inode is unique for a directory (not hard links for directories).
148 * For a file, the parent field points to the first dentry who created this inode.
149 * Syncrhonisation:
150 * - the main_lock (spinlock) is used during the inode tree traversal or for inode
151 *   modification (add/remove children).
152 * - the data_lock (rwlock) is used during read/write accesses to the data stored
153 *   in the mapper.
154 * - the mapper lock (rwlock) is only used during the radix tree traversal to return
155 *   the relevant page for read/write.
156 *****************************************************************************************/
157
158/* this enum define the VFS inode types values */
159
160typedef enum   
161{
162    INODE_TYPE_FILE  =     0x001,      /*! file                                          */
163    INODE_TYPE_DIR   =     0x002,      /*! directory                                     */
164    INODE_TYPE_FIFO  =     0x004,      /*! POSIX named pipe                              */
165    INODE_TYPE_PIPE  =     0x008,      /*! POSIX anonymous pipe                          */
166    INODE_TYPE_SOCK  =     0x010,      /*! POSIX socket                                  */
167    INODE_TYPE_DEV   =     0x020,      /*! device channel                                */
168    INODE_TYPE_SYML  =     0x080,      /*! symbolic link                                 */
169}
170vfs_inode_type_t;
171
172/* this enum define the VFS inode attributes values */
173
174typedef enum 
175{
176    INODE_ATTR_DIRTY   =     0x01,       /* modified versus the value on device          */ 
177    INODE_ATTR_INLOAD  =     0x04,       /* loading from device in progress              */
178    INODE_ATTR_NEW     =     0x08,       /* not saved on device yet                      */
179}
180vfs_inode_attr_t;
181
182typedef struct vfs_inode_s
183{
184        struct vfs_ctx_s * ctx;              /*! local pointer on FS context                 */
185    uint32_t           gc;               /*! generation counter                          */
186        uint32_t           inum;             /*! inode identifier (unique in file system)    */
187        uint32_t           attr;             /*! inode attributes (see above)                */
188        vfs_inode_type_t   type;             /*! inode type (see above)                      */
189        uint32_t           size;             /*! number of bytes                             */
190        uint32_t           links;            /*! number of alias dentry                      */
191        uid_t              uid;              /*! user owner identifier                       */
192        gid_t              gid;              /*! group owner identifier                      */
193    uint32_t           rights;           /*! access rights                               */
194        uint32_t               refcount;         /*! reference counter (all pointers)            */
195        xptr_t             parent_xp;        /*! extended pointer on parent dentry           */
196        xhtab_t            children;         /*! embedded xhtab of children dentries         */
197        remote_rwlock_t    data_lock;        /*! protect read/write to data and to size      */
198        remote_spinlock_t  main_lock;        /*! protect inode tree traversal and modifs     */
199        list_entry_t       list;             /*! member of set of inodes in same cluster     */
200        xlist_entry_t      wait_root;        /*! root of threads waiting on this inode       */
201        struct mapper_s  * mapper;           /*! associated file cache                       */
202        void             * extend;           /*! fs_type_specific inode extension            */
203}
204vfs_inode_t;
205
206/******************************************************************************************
207 * This structure defines a directory entry.
208 * A dentry contains the name of a remote file/dir, an extended pointer on the
209 * inode representing this file/dir, and a local pointer on the inode representing
210 * the parent directory.
211 *****************************************************************************************/
212
213typedef struct vfs_dentry_s
214{
215    struct vfs_ctx_s   * ctx;            /*! local pointer on FS context                 */
216        char                 name[CONFIG_VFS_MAX_NAME_LENGTH];
217        uint32_t             length;         /*! name length (bytes)                         */
218        uint32_t             refcount;       /*! reference counter (all pointers)            */
219    struct vfs_inode_s * parent;         /*! local pointer on parent inode               */
220    xptr_t               child_xp;       /*! extended pointer on child inode             */
221    xlist_entry_t        list;           /*! member of list of dentries with same key    */
222        void               * extend;         /*! FS specific extension                       */
223}
224vfs_dentry_t;
225
226/******************************************************************************************
227 * This file structure describes an open file/directory for a given process.
228 * It is not replicated, and is dynamically allocated in the cluster that contains
229 * the inode, when a thread makes an open() or opendir() system call.
230 * It cannot exist a file structure without an inode structure.
231 * Aa the fd_array (containing extended pointers on the open file descriptors)* is replicated in all process descriptors, we need a references counter.
232 * is replicated in all process descriptors, we need a references counter.
233 *****************************************************************************************/
234
235typedef enum
236{
237    FD_ATTR_READ_ENABLE    = 0x01,     /*! read access possible                         */
238    FD_ATTR_WRITE_ENABLE   = 0x02,     /*! write access possible                        */
239    FD_ATTR_APPEND         = 0x04,     /*! append on each write                         */
240    FD_ATTR_CLOSE_EXEC     = 0x08,     /*! close file on exec                           */
241    FD_ATTR_SYNC           = 0x10,     /*! synchronise FS on each write                 */
242    FD_ATTR_IS_DIR         = 0x20,     /*! this is a directory                          */
243}
244vfs_file_attr_t;
245
246typedef struct vfs_file_s
247{
248        struct vfs_ctx_s      * ctx;        /*! local pointer on FS context.                 */
249        uint32_t                gc;         /*! generation counter                           */
250        vfs_file_attr_t         attr;       /*! file attributes bit vector (see above)       */
251        vfs_inode_type_t        type;       /*! same type as inode                           */
252        uint32_t                offset;     /*! seek position in file                        */
253        uint32_t                refcount;   /*! all pointers on this file descriptor         */
254        remote_rwlock_t         lock;       /*! protect offset modifications                 */
255        struct mapper_s       * mapper;     /*! associated file cache                        */
256        struct vfs_inode_s    * inode;      /*! local pointer on associated inode            */
257        void                  * extend;     /*! FS specific extension                        */
258}
259vfs_file_t;
260
261/******************************************************************************************
262 * This structure define the informations associated to a file descriptor,
263 * returned to user space by the stat() system call.
264 *****************************************************************************************/
265
266typedef struct vfs_stat_s
267{
268        uint32_t    dev;        /*! ID of device containing file                             */
269        uint32_t    ino;        /*! inode number                                             */
270        uint32_t    mode;       /*! protection                                               */
271        uint32_t    nlink;      /*! number of hard links                                     */
272        uint32_t    uid;        /*! user ID of owner                                         */
273        uint32_t    gid;        /*! group ID of owner                                        */
274        uint32_t    rdev;       /*! device ID (if special file)                              */
275        uint64_t    size;       /*! total size, in bytes                                     */
276        uint32_t    blksize;    /*! blocksize for file system I/O                            */
277        uint32_t    blocks;     /*! number of 512B blocks allocated                          */
278        uint64_t    atime;      /*! time of last access                                      */
279        uint64_t    mtime;      /*! time of last modification                                */
280        uint64_t    ctime;      /*! time of last status change                               */
281}
282vfs_stat_t;
283
284/*********************************************************************************************
285 * This structure defines the information associated to a directory entry,
286 * returned to user space by the readdir() system call.
287 ********************************************************************************************/
288
289typedef struct vfs_dirent_s
290{
291    uint32_t    inum;                               /*! inode identifier                    */
292    uint32_t    type;                               /*! inode type                          */
293    char        name[CONFIG_VFS_MAX_NAME_LENGTH];   /*! dentry name                         */
294}
295vfs_dirent_t;
296
297
298
299/*****************************************************************************************/
300/******************** VFS global functions ***********************************************/
301/*****************************************************************************************/ 
302
303
304/******************************************************************************************
305 * This function mount a given file system type for a given process TODO.     
306 *****************************************************************************************/
307error_t vfs_mount_fs_root( struct device_s  * device,
308                                       uint32_t           fs_type,
309                                       struct process_s * process );
310
311
312/*****************************************************************************************/
313/******************* VFS Context related functions ****************************************/
314/*****************************************************************************************/
315
316/******************************************************************************************
317 * This function initialise a (statically allocated) VFS context in local cluster.
318 ******************************************************************************************
319 * @ fs_type        : file system type.
320 * @ attr           : global attributes (for all files in FS.
321 * @ total_clusters : total number of clusters on device.
322 * @ cluster_size   : cluster size on device (bytes).
323 * @ vfs_root_xp    : extended pointer on VFS root inode.
324 * @ extend         : fs_type_specific extension.
325 *****************************************************************************************/
326void vfs_ctx_init( vfs_fs_type_t   type,
327                   uint32_t        attr,
328                       uint32_t        total_clusters,
329                       uint32_t        cluster_size,
330                       xptr_t          vfs_root_xp,
331                   void          * extend );
332
333/******************************************************************************************
334 * This function allocates an inode identifier from the local cluster inum allocator.
335 * The inum respects a fixed format:
336 * - the 16 MSB bits contain the cluster identifier : cxy
337 * - the 16 LSB bits contains the local inode identifier  : lid
338 ******************************************************************************************
339 * @ ctx      : local pointer on file system context.
340 * @ inum     : [ou] buffer for allocated inode identifier.
341 * @ return 0 if success / return non-zero if error.
342 *****************************************************************************************/
343error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
344                            uint32_t  * inum );
345
346/******************************************************************************************
347 * This function release an inode identifier.                                 
348 ******************************************************************************************
349 * @ ctx      : local pointer on file system context.
350 * @ inum     : released inode identifier.
351 *****************************************************************************************/
352void vfs_ctx_inum_release( vfs_ctx_t * ctx,
353                           uint32_t    inum );
354
355
356
357
358/*****************************************************************************************/
359/********************* Inode related functions *******************************************/
360/*****************************************************************************************/
361
362/******************************************************************************************
363 * This function allocates memory from local cluster for an inode descriptor and the
364 * associated mapper. It initialise these descriptors from arguments values.
365 * The parent dentry must have been previously created.
366 * If the client thread is not running in the cluster containing this inode,
367 * it must use the rpc_vfs_inode_create_client() function.
368 ******************************************************************************************
369 * @ dentry_xp  : extended pointer on associated dentry (in parent inode cluster).
370 * @ fs_type    : file system type.
371 * @ inode_type : inode type.
372 * @ extend     : local pointer on vs_type_specific extension.
373 * @ attr       : inode attributes.
374 * @ rights     : inode access rights.
375 * @ uid        : user owner ID.
376 * @ gid        : group owner ID.
377 * @ inode_xp   : [out] buffer for extended pointer on created inode.
378 * # return 0 if success / return ENOMEM or EINVAL if error.
379 *****************************************************************************************/
380error_t vfs_inode_create( xptr_t            dentry_xp,
381                          vfs_fs_type_t     fs_type,
382                          vfs_inode_type_t  inode_type,
383                          void            * extend,
384                          uint32_t          attr,
385                          uint32_t          rights,
386                          uid_t             uid,
387                          gid_t             gid,
388                          xptr_t          * inode_xp );
389
390/******************************************************************************************
391 * This function releases memory allocated to an inode descriptor.
392 * It must be executed by a thread running in the cluster containing the inode,
393 * and the inode refcount must be zero.
394 * If the client thread is not running in the owner cluster, it must use the
395 * rpc_vfs_inode_destroy_client() function.
396 ******************************************************************************************
397 * @ inode  : local pointer on inode descriptor.
398 *****************************************************************************************/
399void vfs_inode_destroy( vfs_inode_t *  inode ); 
400
401/******************************************************************************************
402 * This function scan an existing parent inode directory, identified by the <parent>
403 * argument to find a directory entry identified by the <name> argument, and update
404 * the remote child inode, identified by the <child_xp> argument.
405 * Depending on the file system type, it calls the relevant, FS specific function,
406 * to scan the directory, and set the "type", "size", and "extend" fields.
407 * It must be called by a thread running in the cluster containing the parent inode.
408 ******************************************************************************************
409 * @ parent    : local pointer on parent inode (directory).
410 * @ name      : child name.
411 * @ child_xp  : extended pointer on remote child inode (file or directory)
412 * @ return 0 if success / return ENOENT if not found.
413 *****************************************************************************************/
414error_t vfs_inode_load( vfs_inode_t * parent,
415                        char        * name,
416                        xptr_t        child_xp );
417
418/******************************************************************************************
419 * This function atomically increment/decrement the inode refcount.
420 * It can be called by any thread running in any cluster.
421 *****************************************************************************************/
422void vfs_inode_remote_up( xptr_t  inode_xp );
423void vfs_inode_remote_down( xptr_t  inode_xp );
424
425/******************************************************************************************
426 * This function returns the <size> of a file/dir from a remote inode,
427 * taking the remote_rwlock protecting <size> in READ_MODE.
428 *****************************************************************************************
429 * @ inode_xp  : extended pointer on the remote inode.
430 * @ return the current size.
431 *****************************************************************************************/
432uint32_t vfs_inode_get_size( xptr_t inode_xp );
433
434/******************************************************************************************
435 * This function set the <size> of a file/dir to a remote inode,
436 * taking the remote_rwlock protecting <size> in WRITE_MODE.
437 *****************************************************************************************
438 * @ inode_xp  : extended pointer on the remote inode.
439 * @ size      : value to be written.
440 *****************************************************************************************/
441void vfs_inode_set_size( xptr_t   inode_xp,
442                         uint32_t size );
443
444/******************************************************************************************
445 * This function takes the main lock of a remote inode.
446 * This lock protect all inode fiels, including the children dentries.
447 *****************************************************************************************
448 * @ inode_xp  : extended pointer on the remote inode.
449 *****************************************************************************************/
450void vfs_inode_lock( xptr_t inode_xp );
451
452/******************************************************************************************
453 * This function releases the main lock of a remote inode.
454 * This lock protect all inode fiels, including the children dentries.
455 *****************************************************************************************
456 * @ inode_xp  : extended pointer on the remote inode.
457 *****************************************************************************************/
458void vfs_inode_unlock( xptr_t inode_xp );
459
460/******************************************************************************************
461 * This debug function returns the current owner of the inode main lock.
462 *****************************************************************************************
463 * @ inode_xp  : extended pointer on the remote inode.
464 * @ return extended pointer on owner thread / return XPTR_NULL if lock not taken.
465 *****************************************************************************************/
466xptr_t vfs_inode_owner( xptr_t inode_xp );
467
468/******************************************************************************************
469 * This debug function diplays the name of the inode identified by the <inode_xp>
470 * argument, and all children names for a directory.
471 *****************************************************************************************
472 * @ inode_xp  : extended pointer on the remote inode.
473 *****************************************************************************************/
474void vfs_inode_display( xptr_t inode_xp );
475
476
477
478
479
480
481/******************************************************************************************
482 * This function TODO                                                         
483 *****************************************************************************************/
484error_t vfs_inode_trunc( vfs_inode_t * inode );
485
486/******************************************************************************************
487 * This function TODO                                                         
488 *****************************************************************************************/
489error_t vfs_inode_link( vfs_inode_t * inode,
490                        uint32_t      igc );
491
492/******************************************************************************************
493 * This function TODO                                                         
494 *****************************************************************************************/
495error_t vfs_inode_unlink( vfs_inode_t * inode );
496
497/******************************************************************************************
498 * This function TODO                                                         
499 *****************************************************************************************/
500error_t vfs_inode_stat( vfs_inode_t * inode,
501                        uint32_t      inum );
502
503/******************************************************************************************
504 * This function TODO                                                         
505 *****************************************************************************************/
506error_t vfs_icache_del( vfs_inode_t * inode );
507
508
509/******************************************************************************************
510 * This function TODO  Pourquoi 2 arguments ?
511 *****************************************************************************************/
512error_t vfs_stat_inode( vfs_inode_t * inode,
513                        uint32_t      inum );
514
515
516/*****************************************************************************************/
517/***************** Dentry related functions **********************************************/
518/*****************************************************************************************/
519
520/******************************************************************************************
521 * This function allocates memory from local cluster for a dentry descriptor,
522 * initialises it from  arguments values, and returns the extended pointer on dentry.
523 * The inode field is not initialized, because the inode does not exist yet.
524 * If the client thread is not running in the target cluster for this inode,
525 * it must use the rpc_dentry_create_client() function.
526 ******************************************************************************************
527 * @ fs_type    : file system type.
528 * @ name       : directory entry file/dir name.
529 * @ parent     : local pointer on parent inode.
530 * @ dentry_xp  : [out] buffer for extended pointer on created dentry.
531 * @ return 0 if success / return ENOMEM or EINVAL if error.
532 *****************************************************************************************/
533error_t vfs_dentry_create( vfs_fs_type_t   fs_type,
534                           char          * name,
535                           vfs_inode_t   * parent,
536                           xptr_t        * dentry_xp );
537 
538/******************************************************************************************
539 * This function releases memory allocated to a dentry descriptor.
540 * It must be executed by a thread running in the cluster containing the dentry,
541 * and the dentry refcount must be zero.
542 * If the client thread is not running in the owner cluster, it must use the
543 * rpc_dentry_destroy_client() function.
544 ******************************************************************************************
545 * @ dentry  : local pointer on dentry descriptor.
546 *****************************************************************************************/
547void vfs_dentry_destroy( vfs_dentry_t *  dentry ); 
548
549/******************************************************************************************
550 * These functions atomically increment/decrement the dentry refcount.
551 * It can be called by any thread running in any cluster.
552 *****************************************************************************************/
553void vfs_dentry_remote_up( xptr_t dentry_xp );
554void vfs_dentry_remote_down( xptr_t dentry_xp );
555
556
557/*****************************************************************************************/
558/************************ File descriptor related functions ******************************/
559/*****************************************************************************************/
560
561/******************************************************************************************
562 * This function allocates memory and initializes a new local file descriptor.
563 * It must be executed in the cluster containing the inode.
564 * If the client thread is not running in the owner cluster, it must use the
565 * rpc_vfs_file_create_client() function.
566 ******************************************************************************************
567 * @ inode    : local pointer on associated inode.
568 * @ attr     : file descriptor attributes.
569 * @ file_xp  : [out] buffer for extended pointer on created file descriptor.
570 * @ return 0 if success / return ENOMEM if error.
571 *****************************************************************************************/
572error_t vfs_file_create( vfs_inode_t * inode,
573                         uint32_t      attr,
574                         xptr_t      * file_xp ); 
575
576/******************************************************************************************
577 * This function releases memory allocated to a local file descriptor.
578 * It must be executed by a thread running in the cluster containing the inode,
579 * and the file refcount must be zero.
580 * If the client thread is not running in the owner cluster, it must use the
581 * rpc_vfs_file_destroy_client() function.
582 ******************************************************************************************
583 * @ file  : local pointer on file descriptor.
584 *****************************************************************************************/
585void vfs_file_destroy( vfs_file_t *  file ); 
586
587/******************************************************************************************
588 * These functions increment (resp. decrement) the count field in a remote file
589 * descriptor, using a remote_atomic access.
590 *****************************************************************************************/
591void vfs_file_count_up  ( xptr_t   file_xp );
592void vfs_file_count_down( xptr_t   file_xp );
593
594
595
596/*****************************************************************************************/
597/******************* Inode-Tree related functions ****************************************/ 
598/*****************************************************************************************/ 
599
600/******************************************************************************************
601 * This function randomly selects a cluster for a new inode.
602 ******************************************************************************************
603 * @ returns the selected cluster identifier.
604 *****************************************************************************************/
605cxy_t vfs_cluster_random_select();
606
607/******************************************************************************************
608 * This function returns in a kernel buffer allocated by the caller function,
609 * the pathname of a file/dir identified by an extended pointer on the inode.
610 * It traverse the Inode Tree from the target node to the root.
611 * It can be called by any thread running in any cluster.
612 ******************************************************************************************
613 * @ inode_xp    : pointer on inode descriptor.
614 * @ buffer      : kernel buffer for pathname (must be allocated by caller).
615 * @ size        : max number of characters in buffer.
616 * @ return 0 if success / return EINVAL if buffer too small.
617 *****************************************************************************************/
618error_t vfs_get_path( xptr_t    inode_xp,
619                      char    * buffer,
620                      uint32_t  max_size );
621
622/******************************************************************************************
623 * This function takes a pathname (absolute or relative to cwd) and returns an extended
624 * pointer on the associated inode.
625 * - If a given name in the path is not found in the inode tree, it try to load the missing
626 *   dentry/inode couple, from informations found in the parent directory.
627 * - If this directory entry does not exist on device, it returns an error.
628 * - If the the file identified by the pathname does not exist on device but the
629 *   flag CREATE is set, the inode is created.
630 * - If the the file identified by the pathname exist on device but both flags EXCL
631 *   and CREATE are set, an error is returned.
632 ******************************************************************************************
633 * @ cwd_xp      : extended pointer on current directory (for relative path).
634 * @ pathname    : path in kernel space (can be relative or absolute).
635 * @ lookup_mode : flags defining the working mode (defined above in this file).
636 * @ inode_xp    : [out] buffer for extended pointer on searched inode.
637 * @ return 0 if success / ENOENT if inode not found , EACCES if permissopn denied,
638 *                        EAGAIN if a new complete lookup must be made
639 *****************************************************************************************/
640error_t vfs_lookup( xptr_t             cwd_xp,
641                    char             * pathname,
642                    uint32_t           lookup_mode,
643                                        xptr_t           * inode_xp );
644
645/******************************************************************************************
646 * This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
647 * It can be executed by any thread running in any cluster, as this function
648 * uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
649 * This is done in three steps:
650 * 1) The dentry is created in the cluster containing the existing <parent_xp> inode.
651 *    The new dentry name is defined by the <name> argument.
652 * 2) The inode and its associated mapper are created in cluster identified by <child_cxy>.
653 *    The new inode and the parent inode can have different FS types.
654 * 3) The "child_xp" field in created dentry (pointing on the created inode) is updated.
655 ******************************************************************************************
656 * @ child_cxy  : target cluster for child inode.
657 * @ inode_type : new inode type
658 * @ fs_type    : new inode FS type.
659 * @ parent_xp  : extended pointer on parent inode.
660 * @ name       : new directory entry name.
661 * @ extend     : fs_type_specific inode extension.
662 * @ child_xp   : [out] buffer for extended pointer on child inode.
663 * @ return 0 if success / ENOMEM if dentry or inode cannot be created.
664 *****************************************************************************************/
665error_t vfs_add_child_in_parent( cxy_t              child_cxy,
666                                 vfs_inode_type_t   inode_type,
667                                 vfs_fs_type_t      fs_type,
668                                 xptr_t             parent_xp,
669                                 char             * name,   
670                                 void             * extend,
671                                 xptr_t           * child_xp );
672
673/******************************************************************************************
674 * This function removes a couple dentry/inode from the Inode-Tree, and remove it from
675 * the external device.
676 * TODO                   
677 ******************************************************************************************
678 * @ child_xp   : extended pointer on removed inode.
679 *****************************************************************************************/
680error_t vfs_remove_child_from_parent( xptr_t child_xp );
681
682/******************************************************************************************
683 * This recursive function diplays a complete inode/dentry sub-tree.
684 * Any inode can be selected as the sub-tree root.
685 * TODO this function is not protected against a concurrent inode/dentry removal...
686 ******************************************************************************************
687 * @ inode_xp   : extended pointer on sub-tree root inode.
688 *****************************************************************************************/
689void vfs_display( xptr_t   inode_xp );
690
691
692
693
694
695/*****************************************************************************************/
696/****************** File access API ******************************************************/
697/*****************************************************************************************/
698
699/******************************************************************************************
700 * This function allocates a vfs_file_t structure in the cluster containing the inode
701 * associated to the file identified by <cwd_xp> & <path>.
702 * It initializes it, register it in the reference process fd_array, and returns both
703 * the extended pointer on the remote file descriptor, and the index in the fd_array.
704 * The pathname can be relative to current directory or absolute.
705 * If the inode does not exist in the inode cache, it try to find the file on the mounted
706 * device, and creates an inode on a pseudo randomly selected cluster if found.
707 * It the requested file does not exist on device, it creates a new inode if the
708 * O_CREAT flag is set and return an error otherwise.
709 ******************************************************************************************
710 * @ cwd_xp      : extended pointer on current working directory file descriptor.
711 * @ path        : file pathname (absolute or relative to current directory).
712 * @ flags       : defined above
713 * @ mode        : access rights (as defined by chmod)
714 * @ file_xp     : [out] buffer for extended pointer on created remote file descriptor.
715 * @ file_id     : [out] buffer for created file descriptor index in reference fd_array.
716 * @ return 0 if success / return non-zero if error.
717 *****************************************************************************************/
718error_t vfs_open( xptr_t     cwd_xp,
719                          char     * path,
720                          uint32_t   flags,
721                  uint32_t   mode,
722                          xptr_t   * file_xp,
723                          uint32_t * file_id );
724
725/******************************************************************************************
726 * This function moves <size> bytes between the file identified by the open file descriptor
727 * <file_xp> and a local kernel <buffer> , taken into account the offset in <file_xp>.
728 * The transfer direction is defined by the <to_buffer> argument.
729 ******************************************************************************************
730 * @ to_buffer : mapper -> buffer if true / buffer->mapper if false.
731 * @ file_xp   : extended pointer on the remote file descriptor.
732 * @ buffer    : local pointer on local kernel buffer.
733 * @ size      : requested number of bytes from offset.
734 * @ returns number of bytes actually transfered / -1 if error.
735 *****************************************************************************************/
736error_t vfs_move( bool_t   to_buffer,
737                  xptr_t   file_xp, 
738                  void   * buffer,
739                  uint32_t size );
740
741/******************************************************************************************
742 * This function set a new value in the offset of the open file descriptor <file_xp>.
743 * This value depends on the <whence> argument:
744 * - if VFS_SEEK_SET, new value is <offset>
745 * - if VFS_SEEK_CUR, new value is current_offset + <offset>
746 * - if VFS_SEEK_END, new value is file_size + <offset>
747 ******************************************************************************************
748 * @ file_xp   : extended pointer on the remote open file descriptor.
749 * @ offset    : local pointer on source kernel buffer.
750 * @ whence    : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
751 * @ new_offset : [out] buffer for new offset value.
752 * @ returns 0 if success / -1 if error.
753 *****************************************************************************************/
754error_t vfs_lseek( xptr_t     file_xp,
755                   uint32_t   offset,
756                   uint32_t   whence, 
757                   uint32_t * new_offset );
758
759/******************************************************************************************
760 * This function close an open file descriptor:
761 * 1) All entries in fd_array copies are directly cancelled by the calling thread,
762 *    using remote accesses.
763 * 2) The memory allocated to file descriptor in cluster containing the inode is released.
764 *    It requires a RPC if cluster containing the file descriptor is remote.
765 ******************************************************************************************
766 * @ file_xp     : extended pointer on the file descriptor.
767 * @ file_id     : file descriptor index in fd_array.
768 * @ returns 0 if success / -1 if error.
769 *****************************************************************************************/
770error_t vfs_close( xptr_t    file_xp,
771                   uint32_t  file_id );
772
773/******************************************************************************************
774 * This function remove from the file system a directory entry identified by the
775 * <cwd_xp> & <path> arguments.
776 ******************************************************************************************
777 * @ cwd_xp   : extended pointer on the current working directory file descriptor.
778 * @ path     : pathname (absolute or relative to current directory).
779 * @ returns 0 if success / -1 if error.
780 *****************************************************************************************/
781error_t vfs_unlink( xptr_t   cwd_xp,
782                    char   * path );
783
784/******************************************************************************************
785 * This function returns, in the structure pointed by the <k_stat> kernel pointer,
786 * various informations on the file descriptor identified by the <file_xp> argument.
787 * TODO not implemented yet...
788 ******************************************************************************************
789 * @ file_xp    : extended pointer on the file descriptor of the searched directory .
790 * @ k_dirent   : local pointer on the dirent_t structure in kernel space.
791 * @ returns 0 if success / -1 if error.
792 *****************************************************************************************/
793error_t vfs_stat( xptr_t       file_xp,
794                  vfs_stat_t * k_stat );
795
796/******************************************************************************************
797 * This function returns, in the structure pointed by the <k_dirent> kernel pointer,
798 * various infos on the directory entry currently pointed by the <file_xp> file descriptor.
799 * TODO not implemented yet...
800 ******************************************************************************************
801 * @ file_xp    : extended pointer on the file descriptor of the searched directory .
802 * @ k_dirent   : local pointer on the dirent_t structure in kernel space.
803 * @ returns 0 if success / -1 if error.
804 *****************************************************************************************/
805error_t vfs_readdir( xptr_t         file_xp,
806                     vfs_dirent_t * k_dirent );
807
808/******************************************************************************************
809 * This function  creates a new inode and associated dentry  for the directory defined
810 * by the <cwd_xp> & <path> arguments.
811 * TODO not implemented yet...
812 ******************************************************************************************
813 * @ cwd_xp   : extended pointer on the current working directory file descriptor.
814 * @ path     : pathname (absolute or relative to current directory).                     
815 * @ mode     : access rights (as defined by chmod)
816 * @ returns 0 if success / -1 if error.
817 *****************************************************************************************/
818error_t vfs_mkdir( xptr_t     cwd_xp,
819                   char     * path,
820                   uint32_t   mode );
821
822/******************************************************************************************
823 * This function remove a directory identified by the <cwd_xp / path> arguments
824 * from the file system.
825 * TODO not implemented yet...
826 ******************************************************************************************
827 * @ cwd_xp   : extended pointer on the current working directory file descriptor.
828 * @ path     : pathname (absolute or relative to current directory).                     
829 * @ returns 0 if success / -1 if error.
830 *****************************************************************************************/
831error_t vfs_rmdir( xptr_t   cwd_xp,
832                   char   * path );
833
834/******************************************************************************************
835 * This function makes the directory identified by <cwd_xp / path> arguments to become
836 * the working directory for the calling process.
837 ******************************************************************************************
838 * @ cwd_xp      : extended pointer on current directory file descriptor (relative path).
839 * @ path        : file pathname (absolute or relative to current directory).
840 * return 0 if success / -1 if error.
841 *****************************************************************************************/
842error_t vfs_chdir( xptr_t   cwd_xp,
843                   char   * path );
844
845/******************************************************************************************
846 * This function change the access rigths for the file identified by the <cwd_xp / path>
847 * arguments. The new access rights are defined by the <mode> argument value.
848 ******************************************************************************************
849 * @ cwd_xp      : extended pointer on current directory file descriptor (relative path).
850 * @ path        : file pathname (absolute or relative to current directory).
851 * @ mode        : access rights new value.
852 * return 0 if success / -1 if error.
853 *****************************************************************************************/
854error_t vfs_chmod( xptr_t        cwd_xp,
855                   char        * path,
856                   uint32_t      mode );
857
858/******************************************************************************************
859 * This function creates a named FIFO file.
860 * TODO not implemented yet                                                         
861 ******************************************************************************************
862 * @ path        : FIFO pathname (absolute or relative to current directory).
863 * @ cwd_xp      : extended pointer on the current working directory file descriptor.
864 * @ mode        : access rights new value.
865 *****************************************************************************************/
866error_t vfs_mkfifo( xptr_t       cwd_xp,
867                    char       * path,
868                    uint32_t     mode );
869
870
871/*****************************************************************************************/
872/****************** Mapper access API ****************************************************/
873/*****************************************************************************************/
874
875/******************************************************************************************
876 * This function makes an I/O operation to move one page to/from device from/to the mapper.
877 * It is used in case of MISS on the mapper, or when a dirty page in the mapper must
878 * be updated in the File System.
879 * Depending on the file system type, it calls the proper, FS specific function.
880 * It must be executed by a thread running in the cluster containing the mapper.
881 * The mapper pointer is obtained from the page descriptor.
882 * It takes the mapper lock before launching the IO operation.
883 ******************************************************************************************
884 * @ page      : local pointer on the page descriptor.
885 * @ to_mapper : transfer direction.
886 * @ returns 0 if success / return EINVAL if it cannot access the external device.
887 *****************************************************************************************/
888error_t vfs_mapper_move_page( struct page_s * page,
889                              bool_t          to_mapper );
890
891/******************************************************************************************
892 * This function makes I/O operations to move, from device to mapper, all pages covering
893 * a given inode, identified by the <inode> argument. Inode be a directory or a file,
894 * but this function is mainly used to load (prefetch) a complete directory to the mapper.
895 * Depending on the file system type, it calls the proper, FS specific function.
896 * It must be executed by a thread running in the cluster containing the mapper.
897 * The mapper pointer is obtained from the inode descriptor.
898 * It takes the mapper lock before launching the IO operation.
899 ******************************************************************************************
900 * @ inode  : local pointer on inode.
901 * @ return 0 if success / return EIO if device access failure.
902 *****************************************************************************************/
903error_t vfs_mapper_load_all( vfs_inode_t * inode );
904
905
906
907/* deprecated [AG]
908
909typedef error_t (lookup_inode_t)  ( vfs_inode_t  * parent ,
910                                    vfs_dentry_t * dentry );
911
912typedef error_t (write_inode_t)   ( vfs_inode_t  * inode );
913
914typedef error_t (release_inode_t) ( vfs_inode_t  * inode );
915
916typedef error_t (unlink_inode_t)  ( vfs_inode_t  * parent,
917                                    vfs_dentry_t * dentry,
918                                    uint32_t       flags );
919
920typedef error_t (stat_inode_t)    ( vfs_inode_t  * inode );
921
922typedef error_t (trunc_inode_t)   ( vfs_inode_t  * inode );
923
924typedef error_t (delete_inode_t)  ( vfs_inode_t  * inode );
925
926typedef struct vfs_inode_op_s
927{
928        init_inode_t    * init;   
929        create_inode_t  * create; 
930        lookup_inode_t  * lookup; 
931        write_inode_t   * write;
932        release_inode_t * release;
933        unlink_inode_t  * unlink;
934        delete_inode_t  * delete;
935        stat_inode_t    * stat;
936        trunc_inode_t   * trunc;    // change the size of a file
937}
938vfs_inode_op_t;
939
940 ******************************************************************************************
941 * These typedef define the set of FS specific operations on a VFS DENTRY descriptor.
942 * They must be implemented by any specific file system to be supported by ALMOS_MKH.
943 * This code is not actually used, and is only defined for documentation
944 ******************************************************************************************
945
946
947typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
948
949typedef struct vfs_dentry_op_s
950{
951        vfs_compare_dentry_t * compare;
952}
953vfs_dentry_op_t;
954
955
956 ******************************************************************************************
957 * These typedef define the set of FS specific operations on FILE descriptors
958 * They must be implemented by any specific file system to be supported by ALMOS_MKH.
959 * This code is not actually used, and is only defined for documentation
960 ******************************************************************************************
961
962
963typedef error_t (open_file_t   ) ( vfs_file_t * file,
964                                   void       * extend );
965
966typedef error_t (read_file_t   ) ( vfs_file_t * file,
967                                   char       * buffer,
968                                   uint32_t     count );
969
970typedef error_t (write_file_t  ) ( vfs_file_t * file,
971                                   char       * buffer,
972                                   uint32_t     count );
973
974typedef error_t (lseek_file_t  ) ( vfs_file_t * file );
975
976typedef error_t (close_file_t  ) ( vfs_file_t * file );
977
978typedef error_t (release_file_t) ( vfs_file_t * file );
979
980typedef error_t (read_dir_t    ) ( vfs_file_t * file );
981
982typedef error_t (mmap_file_t   ) ( vfs_file_t    * file ,
983                                   struct vseg_s * vseg );
984
985typedef error_t (munmap_file_t ) ( vfs_file_t    * file,
986                                   struct vseg_s * vseg );
987
988typedef struct vfs_file_op_s
989{
990        open_file_t    * open;
991        read_file_t    * read;
992        write_file_t   * write;
993        lseek_file_t   * lseek;
994        read_dir_t     * readdir;
995        close_file_t   * close;
996        release_file_t * release;
997        mmap_file_t    * mmap;
998        munmap_file_t  * munmap;
999}
1000vfs_file_op_t;
1001
1002*/
1003
1004#endif  /* _VFS_H_ */
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