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source: trunk/kernel/vfs/vfs.c @ 90

Last change on this file since 90 was 50, checked in by alain, 7 years ago
bloup
File size: 43.0 KB

Rev	Line
[1]	1	/*
	2	* vfs.c - Virtual File System implementation.
	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
[14]	26	#include <kernel_config.h>
[1]	27	#include <hal_types.h>
	28	#include <hal_atomic.h>
	29	#include <hal_special.h>
	30	#include <readlock.h>
	31	#include <spinlock.h>
	32	#include <printk.h>
	33	#include <list.h>
	34	#include <xlist.h>
	35	#include <slist.h>
	36	#include <xhtab.h>
[23]	37	#include <rpc.h>
[1]	38	#include <errno.h>
	39	#include <kmem.h>
	40	#include <mapper.h>
	41	#include <thread.h>
	42	#include <process.h>
[23]	43	#include <vfs.h>
[1]	44	#include <fatfs.h>
	45	#include <ramfs.h>
[23]	46	#include <devfs.h>
	47	#include <syscalls.h>
[1]	48
	49
	50	//////////////////////////////////////////////////////////////////////////////////////////
[50]	51	// Extern variables
[1]	52	//////////////////////////////////////////////////////////////////////////////////////////
	53
[50]	54	extern vfs_ctx_t fs_context[FS_TYPES_NR]; // allocate in kernel_init.c
	55
[1]	56	//////////////////////////////////////////////////////////////////////////////////////////
	57	// Context related functions
	58	//////////////////////////////////////////////////////////////////////////////////////////
	59
[23]	60	////////////////////////////////////////////
[1]	61	error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
	62	uint32_t * inum )
	63	{
	64	// get lock on inum allocator
	65	spinlock_lock( &ctx->lock );
	66
	67	// get lid from local inum allocator
[23]	68	uint32_t lid = bitmap_ffc( ctx->bitmap , CONFIG_VFS_MAX_INODES );
[1]	69
	70	if( lid == -1 ) // no more free slot => error
	71	{
	72	// release lock
	73	spinlock_unlock( &ctx->lock );
	74
	75	// return error
	76	return 1;
	77	}
	78	else // found => return inum
	79	{
	80	// set slot allocated
[23]	81	bitmap_set( ctx->bitmap , lid );
[1]	82
	83	// release lock
	84	spinlock_unlock( &ctx->lock );
	85
	86	// return inum
	87	*inum = (((uint32_t)local_cxy) << 16) \| (lid & 0xFFFF);
	88	return 0;
	89	}
	90	}
	91
	92	////////////////////////////////////////////
	93	void vfs_ctx_inum_release( vfs_ctx_t * ctx,
	94	uint32_t inum )
	95	{
[23]	96	bitmap_clear( ctx->bitmap , inum & 0xFFFF );
[1]	97	}
	98
	99	//////////////////////////////////////////////////////////////////////////////////////////
	100	// Inode related functions
	101	//////////////////////////////////////////////////////////////////////////////////////////
	102
[23]	103	//////////////////////////////////////////////////////
	104
	105	error_t vfs_inode_create( xptr_t dentry_xp,
	106	vfs_fs_type_t fs_type,
	107	vfs_inode_type_t inode_type,
	108	uint32_t attr,
	109	uint32_t rights,
	110	uid_t uid,
	111	gid_t gid,
	112	xptr_t * inode_xp )
[1]	113	{
	114	mapper_t * mapper; // associated mapper( to be allocated)
	115	vfs_inode_t * inode; // inode descriptor (to be allocated)
	116	uint32_t inum; // inode identifier (to be allocated)
	117	vfs_ctx_t * ctx; // file system context
	118	kmem_req_t req; // request to kernel memory allocator
	119	error_t error;
	120
[23]	121	// check fs type and get pointer on context
	122	if ( fs_type == FS_TYPE_FATFS ) ctx = &fs_context[FS_TYPE_FATFS];
	123	else if( fs_type == FS_TYPE_RAMFS ) ctx = &fs_context[FS_TYPE_RAMFS];
	124	else if( fs_type == FS_TYPE_DEVFS ) ctx = &fs_context[FS_TYPE_DEVFS];
[1]	125	else
	126	{
	127	ctx = NULL;
	128	printk("\n[PANIC] in %s : undefined file system type\n", __FUNCTION__ );
	129	hal_core_sleep();
	130	}
	131
	132	// allocate inum
	133	error = vfs_ctx_inum_alloc( ctx , &inum );
	134
	135	if( error )
	136	{
	137	printk("\n[ERROR] in %s : cannot allocate inum\n", __FUNCTION__ );
	138	return ENOMEM;
	139	}
	140
	141	// allocate memory for mapper
	142	mapper = mapper_create();
	143
	144	if( mapper == NULL )
	145	{
	146	printk("\n[ERROR] in %s : cannot allocate mapper\n", __FUNCTION__ );
	147	vfs_ctx_inum_release( ctx , inum );
	148	return ENOMEM;
	149	}
	150
[23]	151	// allocate memory for VFS inode descriptor
[1]	152	req.type = KMEM_VFS_INODE;
	153	req.size = sizeof(vfs_inode_t);
	154	req.flags = AF_KERNEL \| AF_ZERO;
	155	inode = (vfs_inode_t *)kmem_alloc( &req );
	156
	157	if( inode == NULL )
	158	{
	159	printk("\n[ERROR] in %s : cannot allocate inode descriptor\n", __FUNCTION__ );
	160	vfs_ctx_inum_release( ctx , inum );
	161	mapper_destroy( mapper );
	162	return ENOMEM;
	163	}
	164
	165	// initialize inode descriptor
	166	inode->gc = 0;
[23]	167	inode->type = inode_type;
[1]	168	inode->inum = inum;
	169	inode->attr = attr;
[23]	170	inode->rights = rights;
[1]	171	inode->uid = uid;
	172	inode->gid = gid;
	173	inode->refcount = 0;
	174	inode->parent_xp = dentry_xp;
	175	inode->ctx = ctx;
	176	inode->mapper = NULL;
	177
	178	// initialise threads waiting queue
	179	xlist_root_init( XPTR( local_cxy , &inode->wait_root ) );
	180
	181	// initialize dentries hash table, if new inode is a directory
[23]	182	if( inode_type == INODE_TYPE_DIR ) xhtab_init( &inode->children , XHTAB_DENTRY_TYPE );
[1]	183
	184	// initialize inode locks
[10]	185	remote_rwlock_init( XPTR( local_cxy , &inode->data_lock ) );
[1]	186	remote_spinlock_init( XPTR( local_cxy , &inode->main_lock ) );
	187
	188	// return extended pointer on inode
	189	*inode_xp = XPTR( local_cxy , inode );
	190	return 0;
	191
	192	} // end vfs_inode_create()
	193
	194	/////////////////////////////////////////////
	195	void vfs_inode_destroy( vfs_inode_t * inode )
	196	{
	197	if( inode->refcount )
	198	{
	199	printk("\n[PANIC] in %s : inode refcount non zero\n", __FUNCTION__ );
	200	hal_core_sleep();
	201	}
	202
	203	// release memory allocated for mapper
	204	mapper_destroy( inode->mapper );
	205
	206	// release memory allocate for inode descriptor
	207	kmem_req_t req;
	208	req.ptr = inode;
	209	req.type = KMEM_VFS_INODE;
	210	kmem_free( &req );
	211
	212	} // end vfs_inode_destroy()
	213
	214	////////////////////////////////////////////
	215	void vfs_inode_remote_up( xptr_t inode_xp )
	216	{
	217	// get inode cluster and local pointer
	218	cxy_t inode_cxy = GET_CXY( inode_xp );
	219	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	220
	221	hal_remote_atomic_add( XPTR( inode_cxy , &inode_ptr->refcount ) , 1 );
	222	}
	223
	224	//////////////////////////////////////////////
	225	void vfs_inode_remote_down( xptr_t inode_xp )
	226	{
	227	// get inode cluster and local pointer
	228	cxy_t inode_cxy = GET_CXY( inode_xp );
	229	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	230
	231	hal_remote_atomic_add( XPTR( inode_cxy , &inode_ptr->refcount ) , -1 );
	232	}
	233
	234	//////////////////////////////////////////////
	235	uint32_t vfs_inode_get_size( xptr_t inode_xp )
	236	{
	237	// get inode cluster and local pointer
	238	cxy_t cxy = GET_CXY( inode_xp );
	239	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	240
	241	// get size
[10]	242	remote_rwlock_rd_lock( XPTR( cxy , &ptr->data_lock ) );
[1]	243	uint32_t size = hal_remote_lw( XPTR( cxy , &ptr->size ) );
[10]	244	remote_rwlock_rd_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	245	return size;
	246	}
	247
	248	/////////////////////////////////////////////////
	249	void vfs_inode_size_set_size( xptr_t inode_xp,
	250	uint32_t size )
	251	{
	252	// get inode cluster and local pointer
	253	cxy_t cxy = GET_CXY( inode_xp );
	254	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	255
	256	// set size
[10]	257	remote_rwlock_wr_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	258	hal_remote_sw( XPTR( cxy , &ptr->size ) , size );
[10]	259	remote_rwlock_wr_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	260	}
	261
	262	///////////////////////////////////////////////
	263	void vfs_inode_remote_unlock( xptr_t inode_xp )
	264	{
	265	// get inode cluster and local pointer
	266	cxy_t cxy = GET_CXY( inode_xp );
	267	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	268
	269	// release the main lock
	270	remote_spinlock_unlock( XPTR( cxy , &ptr->main_lock ) );
	271	}
	272
	273	/////////////////////////////////////////////
	274	void vfs_inode_remote_lock( xptr_t inode_xp )
	275	{
	276	// get inode cluster and local pointer
	277	cxy_t cxy = GET_CXY( inode_xp );
	278	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	279
	280	// get the main lock
	281	remote_spinlock_lock( XPTR( cxy , &ptr->main_lock ) );
	282	}
	283
	284	//////////////////////////////////////////////////////////////////////////////////////////
	285	// Dentry related functions
	286	//////////////////////////////////////////////////////////////////////////////////////////
	287
[23]	288	///////////////////////////////////////////////////
	289	error_t vfs_dentry_create( vfs_fs_type_t fs_type,
	290	char * name,
	291	vfs_inode_t * parent,
	292	xptr_t * dentry_xp )
[1]	293	{
	294	vfs_ctx_t * ctx; // context descriptor
	295	vfs_dentry_t * dentry; // dentry descriptor (to be allocated)
	296	kmem_req_t req; // request to kernel memory allocator
	297
	298	// check type and get pointer on context
[23]	299	if ( fs_type == FS_TYPE_FATFS ) ctx = &fs_context[FS_TYPE_FATFS];
	300	else if( fs_type == FS_TYPE_RAMFS ) ctx = &fs_context[FS_TYPE_RAMFS];
	301	else if( fs_type == FS_TYPE_DEVFS ) ctx = &fs_context[FS_TYPE_DEVFS];
[1]	302	else
	303	{
	304	ctx = NULL;
	305	printk("\n[PANIC] in %s : undefined file system type\n", __FUNCTION__ );
	306	hal_core_sleep();
	307	}
	308
	309	// get name length
	310	uint32_t length = strlen( name );
	311
[23]	312	if( length >= CONFIG_VFS_MAX_NAME_LENGTH )
[1]	313	{
	314	printk("\n[ERROR] in %s : name too long\n", __FUNCTION__ );
	315	return EINVAL;
	316	}
	317
	318	// allocate memory for dentry descriptor
	319	req.type = KMEM_VFS_DENTRY;
	320	req.size = sizeof(vfs_dentry_t);
	321	req.flags = AF_KERNEL \| AF_ZERO;
	322	dentry = (vfs_dentry_t *)kmem_alloc( &req );
	323
	324	if( dentry == NULL )
	325	{
	326	printk("\n[ERROR] in %s : cannot allocate dentry descriptor\n", __FUNCTION__ );
	327	return ENOMEM;
	328	}
	329
	330	// initialize dentry descriptor
[23]	331
[1]	332	dentry->ctx = ctx;
	333	dentry->length = length;
	334	dentry->parent = parent;
	335	strcpy( dentry->name , name );
	336
[23]	337	// register dentry in hash table rooted in parent inode
	338	xhtab_insert( XPTR( local_cxy , &parent->children ),
	339	name,
	340	XPTR( local_cxy , &dentry->xlist ) );
	341
	342	// return extended pointer on dentry
[1]	343	*dentry_xp = XPTR( local_cxy , dentry );
	344
	345	return 0;
	346
	347	} // end vfs_dentry_create()
	348
	349	////////////////////////////////////////////////
	350	void vfs_dentry_destroy( vfs_dentry_t * dentry )
	351	{
	352	if( dentry->refcount )
	353	{
	354	printk("\n[PANIC] in %s : dentry refcount non zero\n", __FUNCTION__ );
	355	hal_core_sleep();
	356	}
	357
	358	kmem_req_t req;
	359	req.ptr = dentry;
	360	req.type = KMEM_VFS_DENTRY;
	361	kmem_free( &req );
	362	}
	363
	364
	365	//////////////////////////////////////////////////////////////////////////////////////////
	366	// File descriptor related functions
	367	//////////////////////////////////////////////////////////////////////////////////////////
	368
[23]	369	/////////////////////////////////////////////
	370	error_t vfs_file_create( vfs_inode_t * inode,
	371	uint32_t attr,
	372	xptr_t * file_xp )
	373	{
	374	vfs_file_t * file;
	375	kmem_req_t req;
	376
	377	// allocate memory for new file descriptor
	378	req.type = KMEM_VFS_FILE;
	379	req.size = sizeof(vfs_file_t);
	380	req.flags = AF_KERNEL \| AF_ZERO;
	381	file = (vfs_file_t *)kmem_alloc( &req );
	382
	383	if( file == NULL ) return ENOMEM;
	384
	385	// initializes new file descriptor
	386	file->gc = 0;
	387	file->type = inode->type;
	388	file->attr = attr;
	389	file->offset = 0;
	390	file->refcount = 0;
	391	file->inode = inode;
	392	file->ctx = inode->ctx;
	393	file->mapper = inode->mapper;
	394
	395	remote_rwlock_init( XPTR( local_cxy , &file->lock ) );
	396
	397	*file_xp = XPTR( local_cxy , file );
	398	return 0;
	399
	400	} // end vfs_file_create()
	401
	402	///////////////////////////////////////////
	403	void vfs_file_destroy( vfs_file_t * file )
	404	{
	405	if( file->refcount )
	406	{
	407	printk("\n[PANIC] in %s : file refcount non zero\n", __FUNCTION__ );
	408	hal_core_sleep();
	409	}
	410
	411	kmem_req_t req;
	412	req.ptr = file;
	413	req.type = KMEM_VFS_FILE;
	414	kmem_free( &req );
	415
	416	} // end vfs_file_destroy()
	417
	418
[1]	419	////////////////////////////////////////
	420	void vfs_file_count_up( xptr_t file_xp )
	421	{
	422	// get file cluster and local pointer
	423	cxy_t file_cxy = GET_CXY( file_xp );
	424	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	425
	426	// atomically increment count
	427	hal_remote_atomic_add( XPTR( file_cxy , &file_ptr->refcount ) , 1 );
	428	}
	429
	430	//////////////////////////////////////////
	431	void vfs_file_count_down( xptr_t file_xp )
	432	{
	433	// get file cluster and local pointer
	434	cxy_t file_cxy = GET_CXY( file_xp );
	435	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	436
	437	// atomically decrement count
	438	hal_remote_atomic_add( XPTR( file_cxy , &file_ptr->refcount ) , -1 );
	439	}
	440
[23]	441	//////////////////////////////////////////////////////////////////////////////////////////
	442	// File access related functions
	443	//////////////////////////////////////////////////////////////////////////////////////////
	444
	445	////////////////////////////////////
	446	error_t vfs_open( xptr_t cwd_xp,
	447	char * path,
	448	uint32_t flags,
	449	uint32_t mode,
	450	xptr_t * new_file_xp,
	451	uint32_t * new_file_id )
[1]	452	{
[23]	453	error_t error;
	454	xptr_t inode_xp; // extended pointer on target inode
	455	cxy_t inode_cxy; // inode cluster identifier
	456	vfs_inode_t * inode_ptr; // inode local pointer
	457	uint32_t file_attr; // file descriptor attributes
	458	uint32_t lookup_mode; // lookup working mode
	459	xptr_t file_xp; // extended pointer on created file descriptor
	460	uint32_t file_id; // created file descriptor index in reference fd_array
[1]	461
[23]	462	// compute lookup working mode
	463	lookup_mode = VFS_LOOKUP_OPEN;
	464	if( (flags & O_DIR ) ) lookup_mode \|= VFS_LOOKUP_DIR;
	465	if( (flags & O_CREAT ) ) lookup_mode \|= VFS_LOOKUP_CREATE;
	466	if( (flags & O_EXCL ) ) lookup_mode \|= VFS_LOOKUP_EXCL;
	467
	468	// compute attributes for the created file
	469	file_attr = 0;
	470	if( (flags & O_RDONLY ) == 0 ) file_attr \|= FD_ATTR_READ_ENABLE;
	471	if( (flags & O_WRONLY ) == 0 ) file_attr \|= FD_ATTR_WRITE_ENABLE;
	472	if( (flags & O_SYNC ) ) file_attr \|= FD_ATTR_SYNC;
	473	if( (flags & O_APPEND ) ) file_attr \|= FD_ATTR_APPEND;
	474	if( (flags & O_CLOEXEC) ) file_attr \|= FD_ATTR_CLOSE_EXEC;
[1]	475
[23]	476	// get extended pointer on target inode
	477	error = vfs_lookup( cwd_xp , path , lookup_mode , &inode_xp );
	478
	479	if( error ) return error;
	480
	481	// get target inode cluster and local pointer
	482	inode_cxy = GET_CXY( inode_xp );
	483	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	484
	485	// create a new file descriptor in cluster containing inode
	486	if( inode_cxy == local_cxy ) // target cluster is local
[1]	487	{
[23]	488	error = vfs_file_create( inode_ptr , file_attr , &file_xp );
[1]	489	}
[23]	490	else // target cluster is remote
	491	{
	492	rpc_vfs_file_create_client( inode_cxy , inode_ptr , file_attr , &file_xp , &error );
	493	}
[1]	494
[23]	495	if( error ) return error;
[1]	496
[23]	497	// allocate and register a new file descriptor index in reference cluster fd_array
	498	error = process_fd_register( file_xp , &file_id );
[1]	499
[23]	500	if( error ) return error;
[1]	501
[23]	502	// success
	503	*new_file_xp = file_xp;
	504	*new_file_id = file_id;
	505	return 0;
[1]	506
[23]	507	} // end vfs_open()
	508
	509	/////////////////////////////////////
	510	error_t vfs_move( bool_t to_buffer,
	511	xptr_t file_xp,
	512	void * buffer,
	513	uint32_t size )
	514	{
	515	assert( ( file_xp != XPTR_NULL ) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	516
	517	cxy_t file_cxy; // remote file descriptor cluster
	518	vfs_file_t * file_ptr; // remote file descriptor local pointer
	519	vfs_inode_type_t inode_type;
	520	uint32_t file_offset; // current offset in file
	521	mapper_t * mapper;
	522	error_t error;
	523
	524	// get cluster and local pointer on remote file descriptor
	525	file_cxy = GET_CXY( file_xp );
	526	file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	527
	528	// get inode type from remote file descriptor
	529	inode_type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
	530
	531	// action depends on inode type
	532	if( inode_type == INODE_TYPE_FILE )
	533	{
	534	// get mapper pointer and file offset from file descriptor
	535	file_offset = hal_remote_lw( XPTR( file_cxy , &file_ptr->offset ) );
	536	mapper = (mapper_t *)hal_remote_lpt( XPTR( file_cxy , &file_ptr->mapper ) );
	537
	538	// move data between mapper and buffer
	539	if( file_cxy == local_cxy )
	540	{
	541	error = mapper_move( mapper,
	542	to_buffer,
	543	file_offset,
	544	buffer,
	545	size );
	546	}
	547	else
	548	{
	549	rpc_mapper_move_client( file_cxy,
	550	mapper,
	551	to_buffer,
	552	file_offset,
	553	buffer,
	554	size,
	555	&error );
	556	}
	557
	558	return error;
	559	}
	560	else if (inode_type == INODE_TYPE_DIR )
	561	{
	562	printk("\n[ERROR] in %s : inode is a directory", __FUNCTION__ );
	563	return EINVAL;
	564	}
	565	else if (inode_type == INODE_TYPE_DEV )
	566	{
	567	// TODO
	568	return 0;
	569	}
	570	else
	571	{
	572	printk("\n[PANIC] in %s : illegal inode type\n", __FUNCTION__ );
	573	hal_core_sleep();
	574	return -1;
	575	}
	576	} // end vfs_access()
	577
	578	//////////////////////////////////////
	579	error_t vfs_lseek( xptr_t file_xp,
	580	uint32_t offset,
	581	uint32_t whence,
	582	uint32_t * new_offset )
	583	{
	584	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	585	hal_core_sleep();
[1]	586	return 0;
	587
[23]	588	assert( ( file_xp != XPTR_NULL ) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	589
	590	} // vfs_lseek()
	591
	592	///////////////////////////////////
	593	error_t vfs_close( xptr_t file_xp,
	594	uint32_t file_id )
[1]	595	{
[23]	596	assert( (file_xp != XPTR_NULL) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	597
	598	assert( (file_id < CONFIG_PROCESS_FILE_MAX_NR) , __FUNCTION__ , "illegal file_id" );
	599
	600	thread_t * this = CURRENT_THREAD;
	601	process_t * process = this->process;
	602
	603	// get cluster and local pointer on remote file descriptor
[1]	604	cxy_t file_cxy = GET_CXY( file_xp );
	605	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	606
[23]	607	// get local pointer on local cluster manager
	608	cluster_t * cluster = LOCAL_CLUSTER;
	609
	610	// get owner process cluster and lpid
	611	cxy_t owner_cxy = CXY_FROM_PID( process->pid );
	612	lpid_t lpid = LPID_FROM_PID( process->pid );
	613
	614	// get extended pointers on copies root and lock
	615	xptr_t root_xp = XPTR( owner_cxy , &cluster->pmgr.copies_root[lpid] );
	616	xptr_t lock_xp = XPTR( owner_cxy , &cluster->pmgr.copies_lock[lpid] );
	617
	618	// take the lock protecting the copies
	619	remote_spinlock_lock( lock_xp );
	620
	621	// 1) loop on the process descriptor copies to cancel all fd_array[file_id] entries
	622	xptr_t iter_xp;
	623	XLIST_FOREACH( root_xp , iter_xp )
[1]	624	{
[23]	625	xptr_t process_xp = XLIST_ELEMENT( iter_xp , process_t , copies_list );
	626	cxy_t process_cxy = GET_CXY( process_xp );
	627	process_t * process_ptr = (process_t *)GET_PTR( process_xp );
[1]	628
[23]	629	xptr_t lock_xp = XPTR( process_cxy , &process_ptr->fd_array.lock );
	630	xptr_t entry_xp = XPTR( process_cxy , &process_ptr->fd_array.array[file_id] );
	631
	632	// lock is required for atomic write of a 64 bits word
	633	remote_rwlock_wr_lock( lock_xp );
	634	hal_remote_swd( entry_xp , XPTR_NULL );
	635	remote_rwlock_wr_unlock( lock_xp );
	636
	637	hal_wbflush();
	638	}
	639
	640	// 2) release memory allocated to file descriptor in remote cluster
	641	if( file_cxy == local_cxy ) // file cluster is local
[1]	642	{
[23]	643	vfs_file_destroy( file_ptr );
	644	}
	645	else // file cluster is local
	646	{
	647	rpc_vfs_file_destroy_client( file_cxy , file_ptr );
	648	}
[1]	649
[23]	650	return 0;
[1]	651
[23]	652	} // end vfs_close()
[1]	653
	654	////////////////////////////////////
[23]	655	error_t vfs_unlink( xptr_t cwd_xp,
	656	char * path )
[1]	657	{
[23]	658	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	659	hal_core_sleep();
[1]	660	return 0;
[23]	661	} // vfs_unlink()
[1]	662
[23]	663	///////////////////////////////////////
	664	error_t vfs_stat( xptr_t file_xp,
	665	vfs_stat_t * k_stat )
[1]	666	{
[23]	667	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	668	hal_core_sleep();
[1]	669	return 0;
	670	}
	671
[23]	672	////////////////////////////////////////////
	673	error_t vfs_readdir( xptr_t file_xp,
	674	vfs_dirent_t * k_dirent )
[1]	675	{
[23]	676	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	677	hal_core_sleep();
[1]	678	return 0;
	679	}
	680
	681	//////////////////////////////////////
[23]	682	error_t vfs_mkdir( xptr_t file_xp,
	683	char * path,
	684	uint32_t mode )
[1]	685	{
[23]	686	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	687	hal_core_sleep();
[1]	688	return 0;
	689	}
	690
[23]	691	////////////////////////////////////
	692	error_t vfs_rmdir( xptr_t file_xp,
	693	char * path )
[1]	694	{
[23]	695	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	696	hal_core_sleep();
[1]	697	return 0;
	698	}
	699
[23]	700	///////////////////////////////////
	701	error_t vfs_chdir( xptr_t cwd_xp,
	702	char * path )
[1]	703	{
[23]	704	error_t error;
	705	xptr_t inode_xp; // extended pointer on target inode
	706	cxy_t inode_cxy; // target inode cluster identifier
	707	vfs_inode_t * inode_ptr; // target inode local pointer
	708	uint32_t mode; // lookup working mode
	709	vfs_inode_type_t inode_type; // target inode type
	710
	711	// set lookup working mode
	712	mode = 0;
	713
	714	// get extended pointer on target inode
	715	error = vfs_lookup( cwd_xp , path , mode , &inode_xp );
	716
	717	if( error ) return error;
	718
	719	// get inode cluster and local pointer
	720	inode_cxy = GET_CXY( inode_xp );
	721	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	722
	723	// get inode type from remote file
	724	inode_type = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->type ) );
	725
	726	if( inode_type != INODE_TYPE_DIR )
	727	{
	728	CURRENT_THREAD->errno = ENOTDIR;
	729	return -1;
	730	}
	731
	732	printk("\n[PANIC] %s non fully implemented\n", __FUNCTION__ );
	733	hal_core_sleep();
[1]	734	return 0;
	735	}
	736
[23]	737	///////////////////////////////////
	738	error_t vfs_chmod( xptr_t cwd_xp,
	739	char * path,
	740	uint32_t rights )
[1]	741	{
[23]	742	error_t error;
	743	xptr_t inode_xp; // extended pointer on target inode
	744	cxy_t inode_cxy; // inode cluster identifier
	745	vfs_inode_t * inode_ptr; // inode local pointer
	746	uint32_t mode; // lookup working mode
	747	vfs_inode_type_t inode_type; // target inode type
	748
	749	// set lookup working mode
	750	mode = 0;
	751
	752	// get extended pointer on target inode
	753	error = vfs_lookup( cwd_xp , path , mode , &inode_xp );
	754
	755	if( error ) return error;
	756
	757	// get inode cluster and local pointer
	758	inode_cxy = GET_CXY( inode_xp );
	759	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	760
	761	// get inode type from remote inode
	762	inode_type = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->type ) );
	763
	764
	765	printk("\n[PANIC] %s non fully implemented\n", __FUNCTION__ );
	766	hal_core_sleep();
[1]	767	return 0;
	768	}
	769
[23]	770	///////////////////////////////////
	771	error_t vfs_mkfifo( xptr_t cwd_xp,
	772	char * path,
	773	uint32_t rights )
	774	{
	775	printk("\n[PANIC] in %s : not implemented yet\n", __FUNCTION__ );
	776	hal_core_sleep();
	777	return 0;
	778	}
[1]	779
	780
	781
[23]	782	/////////////////////////////////////////////////////////////////////////////////////////r
[1]	783	// Inode Tree functions
	784	//////////////////////////////////////////////////////////////////////////////////////////
	785
	786	//////////////////////////////////////////////////////////////////////////////////////////
[23]	787	// This function is used by the vfs_lookup() function.
[1]	788	// It takes an extended pointer on a remote inode (parent directory inode),
	789	// and check access_rights violation for the calling thread.
	790	// It can be used by any thread running in any cluster.
	791	//////////////////////////////////////////////////////////////////////////////////////////
	792	// @ inode_xp : extended pointer on inode.
	793	// @ client_uid : client thread user ID
	794	// @ client_gid : client thread group ID
	795	// @ return true if access rights are violated.
	796	//////////////////////////////////////////////////////////////////////////////////////////
	797	bool_t vfs_access_denied( xptr_t inode_xp,
	798	uint32_t client_uid,
	799	uint32_t client_gid )
	800	{
	801	// get found inode cluster and local pointer
	802	cxy_t inode_cxy = GET_CXY( inode_xp );
	803	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	804
	805	// get inode access mode, UID, and GID
	806	// TODO uint32_t mode = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->mode ) );
	807	uid_t uid = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->uid ) );
	808	gid_t gid = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->gid ) );
	809
	810	// FIXME : me must use mode
	811	if( (uid == client_uid) \|\| (gid == client_gid) ) return false;
	812	else return true;
	813	}
	814
	815	//////////////////////////////////////////////////////////////////////////////////////////
	816	// This static function is used by the vfs_lookup() function.
	817	// It takes an extended pointer on a remote inode (parent directory inode), a directory
	818	// entry name, and returns an extended pointer on the child inode.
	819	// It can be used by any thread running in any cluster.
	820	//////////////////////////////////////////////////////////////////////////////////////////
	821	// @ parent_xp : extended pointer on parent inode in remote cluster.
	822	// @ name : dentry name
	823	// @ child_xp : [out] buffer for extended pointer on child inode.
	824	// @ return true if success / return false if not found.
	825	//////////////////////////////////////////////////////////////////////////////////////////
	826	static bool_t vfs_get_child( xptr_t parent_xp,
	827	char * name,
	828	xptr_t * child_xp )
	829	{
	830	xptr_t xhtab_xp; // extended pointer on hash table containing children dentries
	831	xptr_t dentry_xp; // extended pointer on children dentry
	832
	833	// get parent inode cluster and local pointer
	834	cxy_t parent_cxy = GET_CXY( parent_xp );
	835	vfs_inode_t * parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
	836
	837	// get extended pointer on hash table of children directory entries
	838	xhtab_xp = XPTR( parent_cxy , &parent_ptr->children );
	839
	840	// search extended pointer on matching dentry
	841	dentry_xp = xhtab_lookup( xhtab_xp , name );
	842
	843	if( dentry_xp == XPTR_NULL ) return false;
	844
	845	// get dentry cluster and local pointer
	846	cxy_t dentry_cxy = GET_CXY( dentry_xp );
	847	vfs_dentry_t * dentry_ptr = (vfs_dentry_t *)GET_PTR( dentry_xp );
	848
	849	// return child inode
	850	*child_xp = (xptr_t)hal_remote_lwd( XPTR( dentry_cxy , &dentry_ptr->parent ) );
	851	return true;
	852	}
	853
	854	//////////////////////////////////////////////////////////////////////////////////////////
	855	// This static function is used by the vfs_lookup() function.
	856	// It takes the <current> pointer on a buffer containing a complete pathname, and return
	857	// in the <name> buffer, allocated by the caller, a single name in the path.
	858	// It return also in the <next> pointer the next character to analyse in the path.
	859	// Finally it returns a <last> boolean, that is true when the returned <name> is the
	860	// last name in the path. The names are supposed to be separated by one or several '/'
	861	// characters, that are not written in the <name> buffer.
	862	//////////////////////////////////////////////////////////////////////////////////////////
	863	// @ current : pointer on first character to analyse in buffer containing the path.
	864	// @ name : [out] pointer on buffer allocated by the caller for the returned name.
	865	// @ next : [out] pointer on next character to analyse in buffer containing the path.
	866	// @ last : [out] true if the returned name is the last (NUL character found).
	867	// @ return 0 if success / return EINVAL if string empty (first chracter is NUL).
	868	//////////////////////////////////////////////////////////////////////////////////////////
	869	static error_t vfs_get_name_from_path( char * current,
	870	char * name,
	871	char ** next,
	872	bool_t * last )
	873	{
	874	char * ptr = current;
	875
	876	// skip leading '/' characters
	877	while( *ptr == '/' ) ptr++;
	878
	879	// return EINVAL if string empty
	880	if( *ptr == 0 ) return EINVAL;
	881
	882	// copy all characters in name until NUL or '/'
	883	while( (ptr != 0) && (ptr !='/') ) (name++) = (ptr++);
	884
	885	// return last an next
	886	if( *ptr == 0 ) // last found character is NUL => last name in path
	887	{
	888	*last = true;
	889	}
	890	else // last found character is '/' => skip it
	891	{
	892	*last = false;
	893	*next = ptr + 1;
	894	}
	895
	896	return 0;
	897	}
	898
[23]	899	//////////////////////////////////////////////
	900	error_t vfs_lookup( xptr_t cwd_xp,
	901	char * pathname,
	902	uint32_t mode,
	903	xptr_t * inode_xp )
[1]	904	{
	905	char name[CONFIG_VFS_MAX_NAME_LENGTH]; // one name in path
	906
[23]	907	xptr_t parent_xp; // extended pointer on parent inode
	908	cxy_t parent_cxy; // cluster for parent inode
	909	vfs_inode_t * parent_ptr; // local pointer on parent inode
	910	xptr_t child_xp; // extended pointer on child inode
	911	cxy_t child_cxy; // cluster for child inode
	912	vfs_inode_t * child_ptr; // local pointer on child inode
	913	vfs_inode_type_t inode_type; // child inode type
	914	vfs_fs_type_t fs_type; // File system type
	915	vfs_ctx_t * ctx_ptr; // local pointer on FS context
	916	char * current; // current pointer on path
	917	char * next; // next value for current pointer
	918	bool_t last; // true when the name is the last in path
	919	bool_t found; // true when a child has been found
	920	thread_t * this; // pointer on calling thread descriptor
	921	process_t * process; // pointer on calling process descriptor
	922	error_t error;
[1]	923
	924	this = CURRENT_THREAD;
	925	process = this->process;
	926
	927	// get extended pointer on first inode to search
	928	if( pathname[0] == '/' ) parent_xp = process->vfs_root_xp;
	929	else parent_xp = cwd_xp;
	930
	931	// initialise loop variables
	932	current = pathname;
	933	next = NULL;
	934	last = false;
	935	child_xp = XPTR_NULL;
	936
	937	// take lock on parent inode
	938	vfs_inode_remote_lock( parent_xp );
	939
	940	// break : if one intermediate name not found
	941	// exit : when last name found (i.e. last == true)
	942	do
	943	{
[23]	944	// get one name from path and the last flag
[1]	945	vfs_get_name_from_path( current , name , &next , &last );
	946
	947	// search a child dentry matching name for parent inode
	948	found = vfs_get_child( parent_xp,
	949	name,
	950	&child_xp );
	951
	952	if( found == false ) // child inode not found in inode tree => try to load it
	953	{
	954	// release lock on parent inode
	955	vfs_inode_remote_unlock( parent_xp );
	956
[23]	957	// get cluster and local pointer on parent inode
	958	parent_cxy = GET_CXY( parent_xp );
	959	parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
[1]	960
[23]	961	// get parent inode FS type
	962	ctx_ptr = (vfs_ctx_t *)hal_remote_lpt( XPTR( parent_cxy , &parent_ptr->ctx ) );
	963	fs_type = ctx_ptr->type;
	964
	965	// get child inode type
	966	if( (last == false) \|\| (mode & VFS_LOOKUP_DIR) ) inode_type = INODE_TYPE_DIR;
	967	else inode_type = INODE_TYPE_FILE;
	968
	969	// insert a child dentry/inode in parent inode
	970	error = vfs_add_child_in_parent( inode_type,
	971	fs_type,
	972	parent_xp,
	973	name,
	974	&child_xp );
	975
[1]	976	if( error )
	977	{
	978	printk("\n[ERROR] in %s : inode %s not found in path %s\n",
	979	__FUNCTION__ , name , pathname );
	980	return ENOENT;
	981	}
	982
	983	// take lock on parent inode
	984	vfs_inode_remote_lock( parent_xp );
	985	}
	986
	987	// check access rights
[23]	988	// error = vfs_access_denied( child_xp,
	989	// client_uid,
	990	// client_gid );
	991	// if( error )
	992	// {
	993	// printk("\n[ERROR] in %s : permission denied for %s\n", __FUNCTION__ , name );
	994	// return EACCES;
	995	// }
[1]	996
	997	// take lock on child inode if not last
	998	if( last == false ) vfs_inode_remote_lock( child_xp );
	999
	1000	// release lock on parent inode
	1001	vfs_inode_remote_unlock( parent_xp );
	1002
	1003	// update loop variables
	1004	parent_xp = child_xp;
	1005	current = next;
	1006	}
	1007	while( last == false );
	1008
	1009	vfs_dmsg("\n[INFO] in %s : searched inode found for %s\n",
	1010	__FUNCTION__ , pathname );
	1011
	1012	// get cluster and local pointer on child inode
	1013	child_cxy = GET_CXY( child_xp );
	1014	child_ptr = (vfs_inode_t *)GET_PTR( child_xp );
	1015
	1016	// return searched pointers
	1017	*inode_xp = child_xp;
	1018
	1019	return 0;
	1020
	1021	} // end vfs_lookup()
	1022
	1023
	1024	////////////////////////////////////////////
	1025	error_t vfs_get_path( xptr_t searched_xp,
	1026	char * buffer,
	1027	uint32_t max_size )
	1028	{
	1029	xptr_t dentry_xp; // extended pointer on current dentry
	1030	char * name; // local pointer on current dentry name
	1031	uint32_t length; // length of current dentry name
	1032	uint32_t count; // number of characters written in buffer
	1033	uint32_t index; // slot index in buffer
[23]	1034	xptr_t inode_xp; // extended pointer on
[1]	1035
	1036	// implementation note:
	1037	// we use two variables "index" and "count" because the buffer
	1038	// is actually written in decreasing index order (from leaf to root)
	1039	// TODO : handle conflict with a concurrent rename
	1040	// FIXME : handle synchro in the loop ... [AG]
	1041
	1042	// set the NUL character in buffer / initialise buffer index and count
	1043	buffer[max_size - 1] = 0;
	1044	count = 1;
	1045	index = max_size - 2;
	1046
	1047	// initialize current inode
	1048	inode_xp = searched_xp;
	1049
	1050	// exit when root inode found (i.e. dentry_xp == XPTR_NULL)
	1051	do
	1052	{
	1053	// get inode cluster and local pointer
	1054	cxy_t inode_cxy = GET_CXY( inode_xp );
	1055	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	1056
	1057	// get extended pointer on parent dentry
	1058	dentry_xp = (xptr_t)hal_remote_lwd( XPTR( inode_cxy , inode_ptr->parent_xp ) );
	1059
	1060	// get dentry cluster and local pointer
	1061	cxy_t dentry_cxy = GET_CXY( dentry_xp );
	1062	vfs_dentry_t * dentry_ptr = (vfs_dentry_t *)GET_PTR( dentry_xp );
	1063
	1064	// get dentry name length and pointer
	1065	length = hal_remote_lw( XPTR( dentry_cxy , &dentry_ptr->length ) );
	1066	name = (char *)hal_remote_lpt( XPTR( dentry_cxy , &dentry_ptr->name ) );
	1067
	1068	// update index and count
	1069	index -= (length + 1);
	1070	count += (length + 1);
	1071
	1072	// check buffer overflow
	1073	if( count >= max_size )
	1074	{
	1075	printk("\n[ERROR] in %s : kernel buffer too small\n", __FUNCTION__ );
	1076	return EINVAL;
	1077	}
	1078
	1079	// update pathname
	1080	hal_remote_memcpy( XPTR( local_cxy , &buffer[index + 1] ) ,
	1081	XPTR( dentry_cxy , name ) , length );
	1082	buffer[index] = '/';
	1083
	1084	// get extended pointer on next inode
	1085	inode_xp = (xptr_t)hal_remote_lwd( XPTR( dentry_cxy , dentry_ptr->parent ) );
	1086	}
	1087	while( (dentry_xp != XPTR_NULL) );
	1088
	1089	return 0;
	1090
	1091	} // end vfs_get_path()
	1092
[23]	1093	///////////////////////////////////////////////////////////////
	1094	error_t vfs_add_child_in_parent( vfs_inode_type_t inode_type,
	1095	vfs_fs_type_t fs_type,
	1096	xptr_t parent_xp,
	1097	char * name,
	1098	xptr_t * child_xp )
[1]	1099	{
[23]	1100	error_t error;
	1101	xptr_t dentry_xp; // extended pointer on created dentry
	1102	xptr_t inode_xp; // extended pointer on created inode
	1103	cxy_t parent_cxy; // parent inode cluster identifier
	1104	vfs_inode_t * parent_ptr; // parent inode local pointer
	1105	vfs_ctx_t * parent_ctx; // parent inode context local pointer
[1]	1106
	1107	// get parent inode cluster and local pointer
[23]	1108	parent_cxy = GET_CXY( parent_xp );
	1109	parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
[1]	1110
[23]	1111	// get parent inode context local pointer
	1112	parent_ctx = (vfs_ctx_t *)hal_remote_lpt( XPTR( parent_cxy , &parent_ptr->ctx ) );
	1113
[1]	1114	// create dentry
	1115	if( parent_cxy == local_cxy ) // parent cluster is the local cluster
	1116	{
[23]	1117	error = vfs_dentry_create( fs_type,
[1]	1118	name,
	1119	parent_ptr,
	1120	&dentry_xp );
	1121	}
	1122	else // parent cluster is remote
	1123	{
	1124	rpc_vfs_dentry_create_client( parent_cxy,
[23]	1125	fs_type,
[1]	1126	name,
	1127	parent_ptr,
	1128	&dentry_xp,
	1129	&error );
	1130	}
	1131
	1132	if( error )
	1133	{
	1134	printk("\n[ERROR] in %s : cannot create dentry in cluster %x\n",
	1135	__FUNCTION__ , parent_cxy );
	1136
	1137	return error;
	1138	}
	1139
	1140	// select a target cluster for child inode
	1141	uint32_t x_size = LOCAL_CLUSTER->x_size;
	1142	uint32_t y_size = LOCAL_CLUSTER->y_size;
	1143	uint32_t y_width = LOCAL_CLUSTER->y_width;
	1144	uint32_t index = ( hal_time_stamp() + hal_get_gid() ) % (x_size * y_size);
	1145	uint32_t x = index / y_size;
	1146	uint32_t y = index % y_size;
	1147	cxy_t child_cxy = (x<<y_width) + y;
	1148
	1149	// create child inode TODO : define attr / mode / uid / gid
	1150	uint32_t attr = 0;
	1151	uint32_t mode = 0;
	1152	uint32_t uid = 0;
	1153	uint32_t gid = 0;
	1154
	1155	if( child_cxy == local_cxy ) // child cluster is the local cluster
	1156	{
	1157	error = vfs_inode_create( dentry_xp,
[23]	1158	fs_type,
	1159	inode_type,
[1]	1160	attr,
	1161	mode,
	1162	uid,
	1163	gid,
	1164	&inode_xp );
	1165	}
	1166	else // child cluster is remote
	1167	{
	1168	rpc_vfs_inode_create_client( child_cxy,
	1169	dentry_xp,
[23]	1170	fs_type,
	1171	inode_type,
[1]	1172	attr,
	1173	mode,
	1174	uid,
	1175	gid,
	1176	&inode_xp,
	1177	&error );
	1178	}
	1179
	1180	if( error )
	1181	{
	1182	printk("\n[ERROR] in %s : cannot create inode in cluster %x\n",
	1183	__FUNCTION__ , child_cxy );
	1184
	1185	vfs_dentry_t * dentry = (vfs_dentry_t *)GET_PTR( dentry_xp );
	1186	if( parent_cxy == local_cxy ) vfs_dentry_destroy( dentry );
	1187	else rpc_vfs_dentry_destroy_client( parent_cxy , dentry );
	1188	return error;
	1189	}
	1190
	1191	// success : return extended pointer on child inode
	1192	*child_xp = inode_xp;
	1193	return 0;
	1194
	1195	} // end vfs_add_child_in_parent()
	1196
	1197
[23]	1198
	1199
	1200	//////////////////////////////////////////////////////////////////////////////////////////
	1201	// Mapper related functions
	1202	//////////////////////////////////////////////////////////////////////////////////////////
	1203
	1204	////////////////////////////////////////////////
	1205	error_t vfs_move_page_to_mapper( page_t * page )
	1206	{
	1207	error_t error = 0;
	1208
	1209	assert( (page != NULL) , __FUNCTION__ , "page pointer is NULL\n" );
	1210
	1211	mapper_t * mapper = page->mapper;
	1212
	1213	assert( (mapper != NULL) , __FUNCTION__ , "no mapper for page\n" );
	1214
	1215	// get FS type
	1216	vfs_fs_type_t fs_type = mapper->inode->ctx->type;
	1217
	1218	// update mapper if permitted by file system type
	1219	if( fs_type == FS_TYPE_FATFS )
	1220	{
	1221	// get mapper lock in WRITE_MODE
	1222	rwlock_wr_lock( &mapper->lock );
	1223
	1224	error = fatfs_read_page( page );
	1225
	1226	// release mapper lock
	1227	rwlock_wr_unlock( &mapper->lock );
	1228	}
	1229	else if( fs_type == FS_TYPE_RAMFS )
	1230	{
	1231	assert( false , __FUNCTION__ , "should not be called for RAMFS\n" );
	1232	}
	1233	else if( fs_type == FS_TYPE_DEVFS )
	1234	{
	1235	assert( false , __FUNCTION__ , "should not be called for DEVFS\n" );
	1236	}
	1237	else
	1238	{
	1239	assert( false , __FUNCTION__ , "undefined file system type\n" );
	1240	}
	1241
	1242	return error;
	1243
	1244	} // end vfs_move_page_to_mapper()
	1245
	1246	//////////////////////////////////////////////////
	1247	error_t vfs_move_page_from_mapper( page_t * page )
	1248	{
	1249	error_t error = 0;
	1250
	1251	assert( (page != NULL) , __FUNCTION__ , "page pointer is NULL\n" );
	1252
	1253	mapper_t * mapper = page->mapper;
	1254
	1255	assert( (mapper != NULL) , __FUNCTION__ , "no mapper for page\n" );
	1256
	1257	// get FS type
	1258	vfs_fs_type_t fs_type = mapper->inode->ctx->type;
	1259
	1260	// update file system if permitted by file system type
	1261	if( fs_type == FS_TYPE_FATFS )
	1262	{
	1263	if( page_is_flag( page , PG_DIRTY ) )
	1264	{
	1265	// get mapper lock in READ_MODE
	1266	rwlock_rd_lock( &mapper->lock );
	1267
	1268	error = fatfs_write_page( page );
	1269
	1270	// release mapper lock from READ_MODE
	1271	rwlock_rd_unlock( &mapper->lock );
	1272
	1273	// clear dirty bit if success
	1274	if( error == 0 ) page_undo_dirty( page );
	1275	}
	1276	}
	1277	else if( fs_type == FS_TYPE_RAMFS )
	1278	{
	1279	assert( false , __FUNCTION__ , "should not be called for RAMFS\n" );
	1280	}
	1281	else if( fs_type == FS_TYPE_DEVFS )
	1282	{
	1283	assert( false , __FUNCTION__ , "should not be called for DEVFS\n" );
	1284	}
	1285	else
	1286	{
	1287	assert( false , __FUNCTION__ , "undefined file system type\n" );
	1288	}
	1289
	1290	return error;
	1291
	1292	} // end vfs_move_page_from_mapper()
	1293
	1294

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