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source: trunk/kernel/vfs/vfs.c @ 26

Last change on this file since 26 was 23, checked in by alain, 8 years ago
Introduce syscalls.
File size: 43.3 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	//////////////////////////////////////////////////////////////////////////////////////////
	51	// Global variables
	52	//////////////////////////////////////////////////////////////////////////////////////////
	53
[23]	54	// array of supported FS contexts
[1]	55	vfs_ctx_t fs_context[FS_TYPES_NR];
	56
	57	//////////////////////////////////////////////////////////////////////////////////////////
	58	// Context related functions
	59	//////////////////////////////////////////////////////////////////////////////////////////
	60
[23]	61	////////////////////////////////////////////
[1]	62	error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
	63	uint32_t * inum )
	64	{
	65	// get lock on inum allocator
	66	spinlock_lock( &ctx->lock );
	67
	68	// get lid from local inum allocator
[23]	69	uint32_t lid = bitmap_ffc( ctx->bitmap , CONFIG_VFS_MAX_INODES );
[1]	70
	71	if( lid == -1 ) // no more free slot => error
	72	{
	73	// release lock
	74	spinlock_unlock( &ctx->lock );
	75
	76	// return error
	77	return 1;
	78	}
	79	else // found => return inum
	80	{
	81	// set slot allocated
[23]	82	bitmap_set( ctx->bitmap , lid );
[1]	83
	84	// release lock
	85	spinlock_unlock( &ctx->lock );
	86
	87	// return inum
	88	*inum = (((uint32_t)local_cxy) << 16) \| (lid & 0xFFFF);
	89	return 0;
	90	}
	91	}
	92
	93	////////////////////////////////////////////
	94	void vfs_ctx_inum_release( vfs_ctx_t * ctx,
	95	uint32_t inum )
	96	{
[23]	97	bitmap_clear( ctx->bitmap , inum & 0xFFFF );
[1]	98	}
	99
	100	//////////////////////////////////////////////////////////////////////////////////////////
	101	// Inode related functions
	102	//////////////////////////////////////////////////////////////////////////////////////////
	103
[23]	104	//////////////////////////////////////////////////////
	105
	106	error_t vfs_inode_create( xptr_t dentry_xp,
	107	vfs_fs_type_t fs_type,
	108	vfs_inode_type_t inode_type,
	109	uint32_t attr,
	110	uint32_t rights,
	111	uid_t uid,
	112	gid_t gid,
	113	xptr_t * inode_xp )
[1]	114	{
	115	mapper_t * mapper; // associated mapper( to be allocated)
	116	vfs_inode_t * inode; // inode descriptor (to be allocated)
	117	uint32_t inum; // inode identifier (to be allocated)
	118	vfs_ctx_t * ctx; // file system context
	119	kmem_req_t req; // request to kernel memory allocator
	120	error_t error;
	121
[23]	122	// check fs type and get pointer on context
	123	if ( fs_type == FS_TYPE_FATFS ) ctx = &fs_context[FS_TYPE_FATFS];
	124	else if( fs_type == FS_TYPE_RAMFS ) ctx = &fs_context[FS_TYPE_RAMFS];
	125	else if( fs_type == FS_TYPE_DEVFS ) ctx = &fs_context[FS_TYPE_DEVFS];
[1]	126	else
	127	{
	128	ctx = NULL;
	129	printk("\n[PANIC] in %s : undefined file system type\n", __FUNCTION__ );
	130	hal_core_sleep();
	131	}
	132
	133	// allocate inum
	134	error = vfs_ctx_inum_alloc( ctx , &inum );
	135
	136	if( error )
	137	{
	138	printk("\n[ERROR] in %s : cannot allocate inum\n", __FUNCTION__ );
	139	return ENOMEM;
	140	}
	141
	142	// allocate memory for mapper
	143	mapper = mapper_create();
	144
	145	if( mapper == NULL )
	146	{
	147	printk("\n[ERROR] in %s : cannot allocate mapper\n", __FUNCTION__ );
	148	vfs_ctx_inum_release( ctx , inum );
	149	return ENOMEM;
	150	}
	151
[23]	152	// allocate memory for VFS inode descriptor
[1]	153	req.type = KMEM_VFS_INODE;
	154	req.size = sizeof(vfs_inode_t);
	155	req.flags = AF_KERNEL \| AF_ZERO;
	156	inode = (vfs_inode_t *)kmem_alloc( &req );
	157
	158	if( inode == NULL )
	159	{
	160	printk("\n[ERROR] in %s : cannot allocate inode descriptor\n", __FUNCTION__ );
	161	vfs_ctx_inum_release( ctx , inum );
	162	mapper_destroy( mapper );
	163	return ENOMEM;
	164	}
	165
	166	// initialize inode descriptor
	167	inode->gc = 0;
[23]	168	inode->type = inode_type;
[1]	169	inode->inum = inum;
	170	inode->attr = attr;
[23]	171	inode->rights = rights;
[1]	172	inode->uid = uid;
	173	inode->gid = gid;
	174	inode->refcount = 0;
	175	inode->parent_xp = dentry_xp;
	176	inode->ctx = ctx;
	177	inode->mapper = NULL;
	178
	179	// initialise threads waiting queue
	180	xlist_root_init( XPTR( local_cxy , &inode->wait_root ) );
	181
	182	// initialize dentries hash table, if new inode is a directory
[23]	183	if( inode_type == INODE_TYPE_DIR ) xhtab_init( &inode->children , XHTAB_DENTRY_TYPE );
[1]	184
	185	// initialize inode locks
[10]	186	remote_rwlock_init( XPTR( local_cxy , &inode->data_lock ) );
[1]	187	remote_spinlock_init( XPTR( local_cxy , &inode->main_lock ) );
	188
	189	// return extended pointer on inode
	190	*inode_xp = XPTR( local_cxy , inode );
	191	return 0;
	192
	193	} // end vfs_inode_create()
	194
	195	/////////////////////////////////////////////
	196	void vfs_inode_destroy( vfs_inode_t * inode )
	197	{
	198	if( inode->refcount )
	199	{
	200	printk("\n[PANIC] in %s : inode refcount non zero\n", __FUNCTION__ );
	201	hal_core_sleep();
	202	}
	203
	204	// release memory allocated for mapper
	205	mapper_destroy( inode->mapper );
	206
	207	// release memory allocate for inode descriptor
	208	kmem_req_t req;
	209	req.ptr = inode;
	210	req.type = KMEM_VFS_INODE;
	211	kmem_free( &req );
	212
	213	} // end vfs_inode_destroy()
	214
	215	////////////////////////////////////////////
	216	void vfs_inode_remote_up( xptr_t inode_xp )
	217	{
	218	// get inode cluster and local pointer
	219	cxy_t inode_cxy = GET_CXY( inode_xp );
	220	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	221
	222	hal_remote_atomic_add( XPTR( inode_cxy , &inode_ptr->refcount ) , 1 );
	223	}
	224
	225	//////////////////////////////////////////////
	226	void vfs_inode_remote_down( xptr_t inode_xp )
	227	{
	228	// get inode cluster and local pointer
	229	cxy_t inode_cxy = GET_CXY( inode_xp );
	230	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	231
	232	hal_remote_atomic_add( XPTR( inode_cxy , &inode_ptr->refcount ) , -1 );
	233	}
	234
	235	//////////////////////////////////////////////
	236	uint32_t vfs_inode_get_size( xptr_t inode_xp )
	237	{
	238	// get inode cluster and local pointer
	239	cxy_t cxy = GET_CXY( inode_xp );
	240	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	241
	242	// get size
[10]	243	remote_rwlock_rd_lock( XPTR( cxy , &ptr->data_lock ) );
[1]	244	uint32_t size = hal_remote_lw( XPTR( cxy , &ptr->size ) );
[10]	245	remote_rwlock_rd_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	246	return size;
	247	}
	248
	249	/////////////////////////////////////////////////
	250	void vfs_inode_size_set_size( xptr_t inode_xp,
	251	uint32_t size )
	252	{
	253	// get inode cluster and local pointer
	254	cxy_t cxy = GET_CXY( inode_xp );
	255	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	256
	257	// set size
[10]	258	remote_rwlock_wr_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	259	hal_remote_sw( XPTR( cxy , &ptr->size ) , size );
[10]	260	remote_rwlock_wr_unlock( XPTR( cxy , &ptr->data_lock ) );
[1]	261	}
	262
	263	///////////////////////////////////////////////
	264	void vfs_inode_remote_unlock( xptr_t inode_xp )
	265	{
	266	// get inode cluster and local pointer
	267	cxy_t cxy = GET_CXY( inode_xp );
	268	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	269
	270	// release the main lock
	271	remote_spinlock_unlock( XPTR( cxy , &ptr->main_lock ) );
	272	}
	273
	274	/////////////////////////////////////////////
	275	void vfs_inode_remote_lock( xptr_t inode_xp )
	276	{
	277	// get inode cluster and local pointer
	278	cxy_t cxy = GET_CXY( inode_xp );
	279	vfs_inode_t * ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	280
	281	// get the main lock
	282	remote_spinlock_lock( XPTR( cxy , &ptr->main_lock ) );
	283	}
	284
	285	//////////////////////////////////////////////////////////////////////////////////////////
	286	// Dentry related functions
	287	//////////////////////////////////////////////////////////////////////////////////////////
	288
[23]	289	///////////////////////////////////////////////////
	290	error_t vfs_dentry_create( vfs_fs_type_t fs_type,
	291	char * name,
	292	vfs_inode_t * parent,
	293	xptr_t * dentry_xp )
[1]	294	{
	295	vfs_ctx_t * ctx; // context descriptor
	296	vfs_dentry_t * dentry; // dentry descriptor (to be allocated)
	297	kmem_req_t req; // request to kernel memory allocator
	298
[23]	299	printk("\n @@@ dentry_create : 0 / name = %s\n", name );
	300
[1]	301	// check type and get pointer on context
[23]	302	if ( fs_type == FS_TYPE_FATFS ) ctx = &fs_context[FS_TYPE_FATFS];
	303	else if( fs_type == FS_TYPE_RAMFS ) ctx = &fs_context[FS_TYPE_RAMFS];
	304	else if( fs_type == FS_TYPE_DEVFS ) ctx = &fs_context[FS_TYPE_DEVFS];
[1]	305	else
	306	{
	307	ctx = NULL;
	308	printk("\n[PANIC] in %s : undefined file system type\n", __FUNCTION__ );
	309	hal_core_sleep();
	310	}
	311
	312	// get name length
	313	uint32_t length = strlen( name );
	314
[23]	315	if( length >= CONFIG_VFS_MAX_NAME_LENGTH )
[1]	316	{
	317	printk("\n[ERROR] in %s : name too long\n", __FUNCTION__ );
	318	return EINVAL;
	319	}
	320
[23]	321	printk("\n @@@ dentry_create : 1 / name = %s\n", name );
	322
[1]	323	// allocate memory for dentry descriptor
	324	req.type = KMEM_VFS_DENTRY;
	325	req.size = sizeof(vfs_dentry_t);
	326	req.flags = AF_KERNEL \| AF_ZERO;
	327	dentry = (vfs_dentry_t *)kmem_alloc( &req );
	328
	329	if( dentry == NULL )
	330	{
	331	printk("\n[ERROR] in %s : cannot allocate dentry descriptor\n", __FUNCTION__ );
	332	return ENOMEM;
	333	}
	334
	335	// initialize dentry descriptor
[23]	336
[1]	337	dentry->ctx = ctx;
	338	dentry->length = length;
	339	dentry->parent = parent;
	340	strcpy( dentry->name , name );
	341
[23]	342	printk("\n @@@ dentry_create : 2 / name = %s\n", name );
	343
	344	// register dentry in hash table rooted in parent inode
	345	xhtab_insert( XPTR( local_cxy , &parent->children ),
	346	name,
	347	XPTR( local_cxy , &dentry->xlist ) );
	348
	349	printk("\n @@@ dentry_create : 3 / name = %s\n", name );
	350
	351	// return extended pointer on dentry
[1]	352	*dentry_xp = XPTR( local_cxy , dentry );
	353
	354	return 0;
	355
	356	} // end vfs_dentry_create()
	357
	358	////////////////////////////////////////////////
	359	void vfs_dentry_destroy( vfs_dentry_t * dentry )
	360	{
	361	if( dentry->refcount )
	362	{
	363	printk("\n[PANIC] in %s : dentry refcount non zero\n", __FUNCTION__ );
	364	hal_core_sleep();
	365	}
	366
	367	kmem_req_t req;
	368	req.ptr = dentry;
	369	req.type = KMEM_VFS_DENTRY;
	370	kmem_free( &req );
	371	}
	372
	373
	374	//////////////////////////////////////////////////////////////////////////////////////////
	375	// File descriptor related functions
	376	//////////////////////////////////////////////////////////////////////////////////////////
	377
[23]	378	/////////////////////////////////////////////
	379	error_t vfs_file_create( vfs_inode_t * inode,
	380	uint32_t attr,
	381	xptr_t * file_xp )
	382	{
	383	vfs_file_t * file;
	384	kmem_req_t req;
	385
	386	// allocate memory for new file descriptor
	387	req.type = KMEM_VFS_FILE;
	388	req.size = sizeof(vfs_file_t);
	389	req.flags = AF_KERNEL \| AF_ZERO;
	390	file = (vfs_file_t *)kmem_alloc( &req );
	391
	392	if( file == NULL ) return ENOMEM;
	393
	394	// initializes new file descriptor
	395	file->gc = 0;
	396	file->type = inode->type;
	397	file->attr = attr;
	398	file->offset = 0;
	399	file->refcount = 0;
	400	file->inode = inode;
	401	file->ctx = inode->ctx;
	402	file->mapper = inode->mapper;
	403
	404	remote_rwlock_init( XPTR( local_cxy , &file->lock ) );
	405
	406	*file_xp = XPTR( local_cxy , file );
	407	return 0;
	408
	409	} // end vfs_file_create()
	410
	411	///////////////////////////////////////////
	412	void vfs_file_destroy( vfs_file_t * file )
	413	{
	414	if( file->refcount )
	415	{
	416	printk("\n[PANIC] in %s : file refcount non zero\n", __FUNCTION__ );
	417	hal_core_sleep();
	418	}
	419
	420	kmem_req_t req;
	421	req.ptr = file;
	422	req.type = KMEM_VFS_FILE;
	423	kmem_free( &req );
	424
	425	} // end vfs_file_destroy()
	426
	427
[1]	428	////////////////////////////////////////
	429	void vfs_file_count_up( xptr_t file_xp )
	430	{
	431	// get file cluster and local pointer
	432	cxy_t file_cxy = GET_CXY( file_xp );
	433	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	434
	435	// atomically increment count
	436	hal_remote_atomic_add( XPTR( file_cxy , &file_ptr->refcount ) , 1 );
	437	}
	438
	439	//////////////////////////////////////////
	440	void vfs_file_count_down( xptr_t file_xp )
	441	{
	442	// get file cluster and local pointer
	443	cxy_t file_cxy = GET_CXY( file_xp );
	444	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	445
	446	// atomically decrement count
	447	hal_remote_atomic_add( XPTR( file_cxy , &file_ptr->refcount ) , -1 );
	448	}
	449
[23]	450	//////////////////////////////////////////////////////////////////////////////////////////
	451	// File access related functions
	452	//////////////////////////////////////////////////////////////////////////////////////////
	453
	454	////////////////////////////////////
	455	error_t vfs_open( xptr_t cwd_xp,
	456	char * path,
	457	uint32_t flags,
	458	uint32_t mode,
	459	xptr_t * new_file_xp,
	460	uint32_t * new_file_id )
[1]	461	{
[23]	462	error_t error;
	463	xptr_t inode_xp; // extended pointer on target inode
	464	cxy_t inode_cxy; // inode cluster identifier
	465	vfs_inode_t * inode_ptr; // inode local pointer
	466	uint32_t file_attr; // file descriptor attributes
	467	uint32_t lookup_mode; // lookup working mode
	468	xptr_t file_xp; // extended pointer on created file descriptor
	469	uint32_t file_id; // created file descriptor index in reference fd_array
[1]	470
[23]	471	// compute lookup working mode
	472	lookup_mode = VFS_LOOKUP_OPEN;
	473	if( (flags & O_DIR ) ) lookup_mode \|= VFS_LOOKUP_DIR;
	474	if( (flags & O_CREAT ) ) lookup_mode \|= VFS_LOOKUP_CREATE;
	475	if( (flags & O_EXCL ) ) lookup_mode \|= VFS_LOOKUP_EXCL;
	476
	477	// compute attributes for the created file
	478	file_attr = 0;
	479	if( (flags & O_RDONLY ) == 0 ) file_attr \|= FD_ATTR_READ_ENABLE;
	480	if( (flags & O_WRONLY ) == 0 ) file_attr \|= FD_ATTR_WRITE_ENABLE;
	481	if( (flags & O_SYNC ) ) file_attr \|= FD_ATTR_SYNC;
	482	if( (flags & O_APPEND ) ) file_attr \|= FD_ATTR_APPEND;
	483	if( (flags & O_CLOEXEC) ) file_attr \|= FD_ATTR_CLOSE_EXEC;
[1]	484
[23]	485	// get extended pointer on target inode
	486	error = vfs_lookup( cwd_xp , path , lookup_mode , &inode_xp );
	487
	488	if( error ) return error;
	489
	490	// get target inode cluster and local pointer
	491	inode_cxy = GET_CXY( inode_xp );
	492	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	493
	494	// create a new file descriptor in cluster containing inode
	495	if( inode_cxy == local_cxy ) // target cluster is local
[1]	496	{
[23]	497	error = vfs_file_create( inode_ptr , file_attr , &file_xp );
[1]	498	}
[23]	499	else // target cluster is remote
	500	{
	501	rpc_vfs_file_create_client( inode_cxy , inode_ptr , file_attr , &file_xp , &error );
	502	}
[1]	503
[23]	504	if( error ) return error;
[1]	505
[23]	506	// allocate and register a new file descriptor index in reference cluster fd_array
	507	error = process_fd_register( file_xp , &file_id );
[1]	508
[23]	509	if( error ) return error;
[1]	510
[23]	511	// success
	512	*new_file_xp = file_xp;
	513	*new_file_id = file_id;
	514	return 0;
[1]	515
[23]	516	} // end vfs_open()
	517
	518	/////////////////////////////////////
	519	error_t vfs_move( bool_t to_buffer,
	520	xptr_t file_xp,
	521	void * buffer,
	522	uint32_t size )
	523	{
	524	assert( ( file_xp != XPTR_NULL ) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	525
	526	cxy_t file_cxy; // remote file descriptor cluster
	527	vfs_file_t * file_ptr; // remote file descriptor local pointer
	528	vfs_inode_type_t inode_type;
	529	uint32_t file_offset; // current offset in file
	530	mapper_t * mapper;
	531	error_t error;
	532
	533	// get cluster and local pointer on remote file descriptor
	534	file_cxy = GET_CXY( file_xp );
	535	file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	536
	537	// get inode type from remote file descriptor
	538	inode_type = hal_remote_lw( XPTR( file_cxy , &file_ptr->type ) );
	539
	540	// action depends on inode type
	541	if( inode_type == INODE_TYPE_FILE )
	542	{
	543	// get mapper pointer and file offset from file descriptor
	544	file_offset = hal_remote_lw( XPTR( file_cxy , &file_ptr->offset ) );
	545	mapper = (mapper_t *)hal_remote_lpt( XPTR( file_cxy , &file_ptr->mapper ) );
	546
	547	// move data between mapper and buffer
	548	if( file_cxy == local_cxy )
	549	{
	550	error = mapper_move( mapper,
	551	to_buffer,
	552	file_offset,
	553	buffer,
	554	size );
	555	}
	556	else
	557	{
	558	rpc_mapper_move_client( file_cxy,
	559	mapper,
	560	to_buffer,
	561	file_offset,
	562	buffer,
	563	size,
	564	&error );
	565	}
	566
	567	return error;
	568	}
	569	else if (inode_type == INODE_TYPE_DIR )
	570	{
	571	printk("\n[ERROR] in %s : inode is a directory", __FUNCTION__ );
	572	return EINVAL;
	573	}
	574	else if (inode_type == INODE_TYPE_DEV )
	575	{
	576	// TODO
	577	return 0;
	578	}
	579	else
	580	{
	581	printk("\n[PANIC] in %s : illegal inode type\n", __FUNCTION__ );
	582	hal_core_sleep();
	583	return -1;
	584	}
	585	} // end vfs_access()
	586
	587	//////////////////////////////////////
	588	error_t vfs_lseek( xptr_t file_xp,
	589	uint32_t offset,
	590	uint32_t whence,
	591	uint32_t * new_offset )
	592	{
	593	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	594	hal_core_sleep();
[1]	595	return 0;
	596
[23]	597	assert( ( file_xp != XPTR_NULL ) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	598
	599	} // vfs_lseek()
	600
	601	///////////////////////////////////
	602	error_t vfs_close( xptr_t file_xp,
	603	uint32_t file_id )
[1]	604	{
[23]	605	assert( (file_xp != XPTR_NULL) , __FUNCTION__ , "file_xp == XPTR_NULL" );
	606
	607	assert( (file_id < CONFIG_PROCESS_FILE_MAX_NR) , __FUNCTION__ , "illegal file_id" );
	608
	609	thread_t * this = CURRENT_THREAD;
	610	process_t * process = this->process;
	611
	612	// get cluster and local pointer on remote file descriptor
[1]	613	cxy_t file_cxy = GET_CXY( file_xp );
	614	vfs_file_t * file_ptr = (vfs_file_t *)GET_PTR( file_xp );
	615
[23]	616	// get local pointer on local cluster manager
	617	cluster_t * cluster = LOCAL_CLUSTER;
	618
	619	// get owner process cluster and lpid
	620	cxy_t owner_cxy = CXY_FROM_PID( process->pid );
	621	lpid_t lpid = LPID_FROM_PID( process->pid );
	622
	623	// get extended pointers on copies root and lock
	624	xptr_t root_xp = XPTR( owner_cxy , &cluster->pmgr.copies_root[lpid] );
	625	xptr_t lock_xp = XPTR( owner_cxy , &cluster->pmgr.copies_lock[lpid] );
	626
	627	// take the lock protecting the copies
	628	remote_spinlock_lock( lock_xp );
	629
	630	// 1) loop on the process descriptor copies to cancel all fd_array[file_id] entries
	631	xptr_t iter_xp;
	632	XLIST_FOREACH( root_xp , iter_xp )
[1]	633	{
[23]	634	xptr_t process_xp = XLIST_ELEMENT( iter_xp , process_t , copies_list );
	635	cxy_t process_cxy = GET_CXY( process_xp );
	636	process_t * process_ptr = (process_t *)GET_PTR( process_xp );
[1]	637
[23]	638	xptr_t lock_xp = XPTR( process_cxy , &process_ptr->fd_array.lock );
	639	xptr_t entry_xp = XPTR( process_cxy , &process_ptr->fd_array.array[file_id] );
	640
	641	// lock is required for atomic write of a 64 bits word
	642	remote_rwlock_wr_lock( lock_xp );
	643	hal_remote_swd( entry_xp , XPTR_NULL );
	644	remote_rwlock_wr_unlock( lock_xp );
	645
	646	hal_wbflush();
	647	}
	648
	649	// 2) release memory allocated to file descriptor in remote cluster
	650	if( file_cxy == local_cxy ) // file cluster is local
[1]	651	{
[23]	652	vfs_file_destroy( file_ptr );
	653	}
	654	else // file cluster is local
	655	{
	656	rpc_vfs_file_destroy_client( file_cxy , file_ptr );
	657	}
[1]	658
[23]	659	return 0;
[1]	660
[23]	661	} // end vfs_close()
[1]	662
	663	////////////////////////////////////
[23]	664	error_t vfs_unlink( xptr_t cwd_xp,
	665	char * path )
[1]	666	{
[23]	667	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	668	hal_core_sleep();
[1]	669	return 0;
[23]	670	} // vfs_unlink()
[1]	671
[23]	672	///////////////////////////////////////
	673	error_t vfs_stat( xptr_t file_xp,
	674	vfs_stat_t * k_stat )
[1]	675	{
[23]	676	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	677	hal_core_sleep();
[1]	678	return 0;
	679	}
	680
[23]	681	////////////////////////////////////////////
	682	error_t vfs_readdir( xptr_t file_xp,
	683	vfs_dirent_t * k_dirent )
[1]	684	{
[23]	685	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	686	hal_core_sleep();
[1]	687	return 0;
	688	}
	689
	690	//////////////////////////////////////
[23]	691	error_t vfs_mkdir( xptr_t file_xp,
	692	char * path,
	693	uint32_t mode )
[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_rmdir( xptr_t file_xp,
	702	char * path )
[1]	703	{
[23]	704	printk("\n[PANIC] %s non implemented\n", __FUNCTION__ );
	705	hal_core_sleep();
[1]	706	return 0;
	707	}
	708
[23]	709	///////////////////////////////////
	710	error_t vfs_chdir( xptr_t cwd_xp,
	711	char * path )
[1]	712	{
[23]	713	error_t error;
	714	xptr_t inode_xp; // extended pointer on target inode
	715	cxy_t inode_cxy; // target inode cluster identifier
	716	vfs_inode_t * inode_ptr; // target inode local pointer
	717	uint32_t mode; // lookup working mode
	718	vfs_inode_type_t inode_type; // target inode type
	719
	720	// set lookup working mode
	721	mode = 0;
	722
	723	// get extended pointer on target inode
	724	error = vfs_lookup( cwd_xp , path , mode , &inode_xp );
	725
	726	if( error ) return error;
	727
	728	// get inode cluster and local pointer
	729	inode_cxy = GET_CXY( inode_xp );
	730	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	731
	732	// get inode type from remote file
	733	inode_type = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->type ) );
	734
	735	if( inode_type != INODE_TYPE_DIR )
	736	{
	737	CURRENT_THREAD->errno = ENOTDIR;
	738	return -1;
	739	}
	740
	741	printk("\n[PANIC] %s non fully implemented\n", __FUNCTION__ );
	742	hal_core_sleep();
[1]	743	return 0;
	744	}
	745
[23]	746	///////////////////////////////////
	747	error_t vfs_chmod( xptr_t cwd_xp,
	748	char * path,
	749	uint32_t rights )
[1]	750	{
[23]	751	error_t error;
	752	xptr_t inode_xp; // extended pointer on target inode
	753	cxy_t inode_cxy; // inode cluster identifier
	754	vfs_inode_t * inode_ptr; // inode local pointer
	755	uint32_t mode; // lookup working mode
	756	vfs_inode_type_t inode_type; // target inode type
	757
	758	// set lookup working mode
	759	mode = 0;
	760
	761	// get extended pointer on target inode
	762	error = vfs_lookup( cwd_xp , path , mode , &inode_xp );
	763
	764	if( error ) return error;
	765
	766	// get inode cluster and local pointer
	767	inode_cxy = GET_CXY( inode_xp );
	768	inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	769
	770	// get inode type from remote inode
	771	inode_type = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->type ) );
	772
	773
	774	printk("\n[PANIC] %s non fully implemented\n", __FUNCTION__ );
	775	hal_core_sleep();
[1]	776	return 0;
	777	}
	778
[23]	779	///////////////////////////////////
	780	error_t vfs_mkfifo( xptr_t cwd_xp,
	781	char * path,
	782	uint32_t rights )
	783	{
	784	printk("\n[PANIC] in %s : not implemented yet\n", __FUNCTION__ );
	785	hal_core_sleep();
	786	return 0;
	787	}
[1]	788
	789
	790
[23]	791	/////////////////////////////////////////////////////////////////////////////////////////r
[1]	792	// Inode Tree functions
	793	//////////////////////////////////////////////////////////////////////////////////////////
	794
	795	//////////////////////////////////////////////////////////////////////////////////////////
[23]	796	// This function is used by the vfs_lookup() function.
[1]	797	// It takes an extended pointer on a remote inode (parent directory inode),
	798	// and check access_rights violation for the calling thread.
	799	// It can be used by any thread running in any cluster.
	800	//////////////////////////////////////////////////////////////////////////////////////////
	801	// @ inode_xp : extended pointer on inode.
	802	// @ client_uid : client thread user ID
	803	// @ client_gid : client thread group ID
	804	// @ return true if access rights are violated.
	805	//////////////////////////////////////////////////////////////////////////////////////////
	806	bool_t vfs_access_denied( xptr_t inode_xp,
	807	uint32_t client_uid,
	808	uint32_t client_gid )
	809	{
	810	// get found inode cluster and local pointer
	811	cxy_t inode_cxy = GET_CXY( inode_xp );
	812	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	813
	814	// get inode access mode, UID, and GID
	815	// TODO uint32_t mode = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->mode ) );
	816	uid_t uid = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->uid ) );
	817	gid_t gid = hal_remote_lw( XPTR( inode_cxy , &inode_ptr->gid ) );
	818
	819	// FIXME : me must use mode
	820	if( (uid == client_uid) \|\| (gid == client_gid) ) return false;
	821	else return true;
	822	}
	823
	824	//////////////////////////////////////////////////////////////////////////////////////////
	825	// This static function is used by the vfs_lookup() function.
	826	// It takes an extended pointer on a remote inode (parent directory inode), a directory
	827	// entry name, and returns an extended pointer on the child inode.
	828	// It can be used by any thread running in any cluster.
	829	//////////////////////////////////////////////////////////////////////////////////////////
	830	// @ parent_xp : extended pointer on parent inode in remote cluster.
	831	// @ name : dentry name
	832	// @ child_xp : [out] buffer for extended pointer on child inode.
	833	// @ return true if success / return false if not found.
	834	//////////////////////////////////////////////////////////////////////////////////////////
	835	static bool_t vfs_get_child( xptr_t parent_xp,
	836	char * name,
	837	xptr_t * child_xp )
	838	{
	839	xptr_t xhtab_xp; // extended pointer on hash table containing children dentries
	840	xptr_t dentry_xp; // extended pointer on children dentry
	841
	842	// get parent inode cluster and local pointer
	843	cxy_t parent_cxy = GET_CXY( parent_xp );
	844	vfs_inode_t * parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
	845
	846	// get extended pointer on hash table of children directory entries
	847	xhtab_xp = XPTR( parent_cxy , &parent_ptr->children );
	848
	849	// search extended pointer on matching dentry
	850	dentry_xp = xhtab_lookup( xhtab_xp , name );
	851
	852	if( dentry_xp == XPTR_NULL ) return false;
	853
	854	// get dentry cluster and local pointer
	855	cxy_t dentry_cxy = GET_CXY( dentry_xp );
	856	vfs_dentry_t * dentry_ptr = (vfs_dentry_t *)GET_PTR( dentry_xp );
	857
	858	// return child inode
	859	*child_xp = (xptr_t)hal_remote_lwd( XPTR( dentry_cxy , &dentry_ptr->parent ) );
	860	return true;
	861	}
	862
	863	//////////////////////////////////////////////////////////////////////////////////////////
	864	// This static function is used by the vfs_lookup() function.
	865	// It takes the <current> pointer on a buffer containing a complete pathname, and return
	866	// in the <name> buffer, allocated by the caller, a single name in the path.
	867	// It return also in the <next> pointer the next character to analyse in the path.
	868	// Finally it returns a <last> boolean, that is true when the returned <name> is the
	869	// last name in the path. The names are supposed to be separated by one or several '/'
	870	// characters, that are not written in the <name> buffer.
	871	//////////////////////////////////////////////////////////////////////////////////////////
	872	// @ current : pointer on first character to analyse in buffer containing the path.
	873	// @ name : [out] pointer on buffer allocated by the caller for the returned name.
	874	// @ next : [out] pointer on next character to analyse in buffer containing the path.
	875	// @ last : [out] true if the returned name is the last (NUL character found).
	876	// @ return 0 if success / return EINVAL if string empty (first chracter is NUL).
	877	//////////////////////////////////////////////////////////////////////////////////////////
	878	static error_t vfs_get_name_from_path( char * current,
	879	char * name,
	880	char ** next,
	881	bool_t * last )
	882	{
	883	char * ptr = current;
	884
	885	// skip leading '/' characters
	886	while( *ptr == '/' ) ptr++;
	887
	888	// return EINVAL if string empty
	889	if( *ptr == 0 ) return EINVAL;
	890
	891	// copy all characters in name until NUL or '/'
	892	while( (ptr != 0) && (ptr !='/') ) (name++) = (ptr++);
	893
	894	// return last an next
	895	if( *ptr == 0 ) // last found character is NUL => last name in path
	896	{
	897	*last = true;
	898	}
	899	else // last found character is '/' => skip it
	900	{
	901	*last = false;
	902	*next = ptr + 1;
	903	}
	904
	905	return 0;
	906	}
	907
[23]	908	//////////////////////////////////////////////
	909	error_t vfs_lookup( xptr_t cwd_xp,
	910	char * pathname,
	911	uint32_t mode,
	912	xptr_t * inode_xp )
[1]	913	{
	914	char name[CONFIG_VFS_MAX_NAME_LENGTH]; // one name in path
	915
[23]	916	xptr_t parent_xp; // extended pointer on parent inode
	917	cxy_t parent_cxy; // cluster for parent inode
	918	vfs_inode_t * parent_ptr; // local pointer on parent inode
	919	xptr_t child_xp; // extended pointer on child inode
	920	cxy_t child_cxy; // cluster for child inode
	921	vfs_inode_t * child_ptr; // local pointer on child inode
	922	vfs_inode_type_t inode_type; // child inode type
	923	vfs_fs_type_t fs_type; // File system type
	924	vfs_ctx_t * ctx_ptr; // local pointer on FS context
	925	char * current; // current pointer on path
	926	char * next; // next value for current pointer
	927	bool_t last; // true when the name is the last in path
	928	bool_t found; // true when a child has been found
	929	thread_t * this; // pointer on calling thread descriptor
	930	process_t * process; // pointer on calling process descriptor
	931	error_t error;
[1]	932
	933	this = CURRENT_THREAD;
	934	process = this->process;
	935
	936	// get extended pointer on first inode to search
	937	if( pathname[0] == '/' ) parent_xp = process->vfs_root_xp;
	938	else parent_xp = cwd_xp;
	939
	940	// initialise loop variables
	941	current = pathname;
	942	next = NULL;
	943	last = false;
	944	child_xp = XPTR_NULL;
	945
	946	// take lock on parent inode
	947	vfs_inode_remote_lock( parent_xp );
	948
	949	// break : if one intermediate name not found
	950	// exit : when last name found (i.e. last == true)
	951	do
	952	{
[23]	953	// get one name from path and the last flag
[1]	954	vfs_get_name_from_path( current , name , &next , &last );
	955
	956	// search a child dentry matching name for parent inode
	957	found = vfs_get_child( parent_xp,
	958	name,
	959	&child_xp );
	960
	961	if( found == false ) // child inode not found in inode tree => try to load it
	962	{
	963	// release lock on parent inode
	964	vfs_inode_remote_unlock( parent_xp );
	965
[23]	966	// get cluster and local pointer on parent inode
	967	parent_cxy = GET_CXY( parent_xp );
	968	parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
[1]	969
[23]	970	// get parent inode FS type
	971	ctx_ptr = (vfs_ctx_t *)hal_remote_lpt( XPTR( parent_cxy , &parent_ptr->ctx ) );
	972	fs_type = ctx_ptr->type;
	973
	974	// get child inode type
	975	if( (last == false) \|\| (mode & VFS_LOOKUP_DIR) ) inode_type = INODE_TYPE_DIR;
	976	else inode_type = INODE_TYPE_FILE;
	977
	978	// insert a child dentry/inode in parent inode
	979	error = vfs_add_child_in_parent( inode_type,
	980	fs_type,
	981	parent_xp,
	982	name,
	983	&child_xp );
	984
[1]	985	if( error )
	986	{
	987	printk("\n[ERROR] in %s : inode %s not found in path %s\n",
	988	__FUNCTION__ , name , pathname );
	989	return ENOENT;
	990	}
	991
	992	// take lock on parent inode
	993	vfs_inode_remote_lock( parent_xp );
	994	}
	995
	996	// check access rights
[23]	997	// error = vfs_access_denied( child_xp,
	998	// client_uid,
	999	// client_gid );
	1000	// if( error )
	1001	// {
	1002	// printk("\n[ERROR] in %s : permission denied for %s\n", __FUNCTION__ , name );
	1003	// return EACCES;
	1004	// }
[1]	1005
	1006	// take lock on child inode if not last
	1007	if( last == false ) vfs_inode_remote_lock( child_xp );
	1008
	1009	// release lock on parent inode
	1010	vfs_inode_remote_unlock( parent_xp );
	1011
	1012	// update loop variables
	1013	parent_xp = child_xp;
	1014	current = next;
	1015	}
	1016	while( last == false );
	1017
	1018	vfs_dmsg("\n[INFO] in %s : searched inode found for %s\n",
	1019	__FUNCTION__ , pathname );
	1020
	1021	// get cluster and local pointer on child inode
	1022	child_cxy = GET_CXY( child_xp );
	1023	child_ptr = (vfs_inode_t *)GET_PTR( child_xp );
	1024
	1025	// return searched pointers
	1026	*inode_xp = child_xp;
	1027
	1028	return 0;
	1029
	1030	} // end vfs_lookup()
	1031
	1032
	1033	////////////////////////////////////////////
	1034	error_t vfs_get_path( xptr_t searched_xp,
	1035	char * buffer,
	1036	uint32_t max_size )
	1037	{
	1038	xptr_t dentry_xp; // extended pointer on current dentry
	1039	char * name; // local pointer on current dentry name
	1040	uint32_t length; // length of current dentry name
	1041	uint32_t count; // number of characters written in buffer
	1042	uint32_t index; // slot index in buffer
[23]	1043	xptr_t inode_xp; // extended pointer on
[1]	1044
	1045	// implementation note:
	1046	// we use two variables "index" and "count" because the buffer
	1047	// is actually written in decreasing index order (from leaf to root)
	1048	// TODO : handle conflict with a concurrent rename
	1049	// FIXME : handle synchro in the loop ... [AG]
	1050
	1051	// set the NUL character in buffer / initialise buffer index and count
	1052	buffer[max_size - 1] = 0;
	1053	count = 1;
	1054	index = max_size - 2;
	1055
	1056	// initialize current inode
	1057	inode_xp = searched_xp;
	1058
	1059	// exit when root inode found (i.e. dentry_xp == XPTR_NULL)
	1060	do
	1061	{
	1062	// get inode cluster and local pointer
	1063	cxy_t inode_cxy = GET_CXY( inode_xp );
	1064	vfs_inode_t * inode_ptr = (vfs_inode_t *)GET_PTR( inode_xp );
	1065
	1066	// get extended pointer on parent dentry
	1067	dentry_xp = (xptr_t)hal_remote_lwd( XPTR( inode_cxy , inode_ptr->parent_xp ) );
	1068
	1069	// get dentry cluster and local pointer
	1070	cxy_t dentry_cxy = GET_CXY( dentry_xp );
	1071	vfs_dentry_t * dentry_ptr = (vfs_dentry_t *)GET_PTR( dentry_xp );
	1072
	1073	// get dentry name length and pointer
	1074	length = hal_remote_lw( XPTR( dentry_cxy , &dentry_ptr->length ) );
	1075	name = (char *)hal_remote_lpt( XPTR( dentry_cxy , &dentry_ptr->name ) );
	1076
	1077	// update index and count
	1078	index -= (length + 1);
	1079	count += (length + 1);
	1080
	1081	// check buffer overflow
	1082	if( count >= max_size )
	1083	{
	1084	printk("\n[ERROR] in %s : kernel buffer too small\n", __FUNCTION__ );
	1085	return EINVAL;
	1086	}
	1087
	1088	// update pathname
	1089	hal_remote_memcpy( XPTR( local_cxy , &buffer[index + 1] ) ,
	1090	XPTR( dentry_cxy , name ) , length );
	1091	buffer[index] = '/';
	1092
	1093	// get extended pointer on next inode
	1094	inode_xp = (xptr_t)hal_remote_lwd( XPTR( dentry_cxy , dentry_ptr->parent ) );
	1095	}
	1096	while( (dentry_xp != XPTR_NULL) );
	1097
	1098	return 0;
	1099
	1100	} // end vfs_get_path()
	1101
[23]	1102	///////////////////////////////////////////////////////////////
	1103	error_t vfs_add_child_in_parent( vfs_inode_type_t inode_type,
	1104	vfs_fs_type_t fs_type,
	1105	xptr_t parent_xp,
	1106	char * name,
	1107	xptr_t * child_xp )
[1]	1108	{
[23]	1109	error_t error;
	1110	xptr_t dentry_xp; // extended pointer on created dentry
	1111	xptr_t inode_xp; // extended pointer on created inode
	1112	cxy_t parent_cxy; // parent inode cluster identifier
	1113	vfs_inode_t * parent_ptr; // parent inode local pointer
	1114	vfs_ctx_t * parent_ctx; // parent inode context local pointer
[1]	1115
	1116	// get parent inode cluster and local pointer
[23]	1117	parent_cxy = GET_CXY( parent_xp );
	1118	parent_ptr = (vfs_inode_t *)GET_PTR( parent_xp );
[1]	1119
[23]	1120	// get parent inode context local pointer
	1121	parent_ctx = (vfs_ctx_t *)hal_remote_lpt( XPTR( parent_cxy , &parent_ptr->ctx ) );
	1122
[1]	1123	// create dentry
	1124	if( parent_cxy == local_cxy ) // parent cluster is the local cluster
	1125	{
[23]	1126	error = vfs_dentry_create( fs_type,
[1]	1127	name,
	1128	parent_ptr,
	1129	&dentry_xp );
	1130	}
	1131	else // parent cluster is remote
	1132	{
	1133	rpc_vfs_dentry_create_client( parent_cxy,
[23]	1134	fs_type,
[1]	1135	name,
	1136	parent_ptr,
	1137	&dentry_xp,
	1138	&error );
	1139	}
	1140
	1141	if( error )
	1142	{
	1143	printk("\n[ERROR] in %s : cannot create dentry in cluster %x\n",
	1144	__FUNCTION__ , parent_cxy );
	1145
	1146	return error;
	1147	}
	1148
	1149	// select a target cluster for child inode
	1150	uint32_t x_size = LOCAL_CLUSTER->x_size;
	1151	uint32_t y_size = LOCAL_CLUSTER->y_size;
	1152	uint32_t y_width = LOCAL_CLUSTER->y_width;
	1153	uint32_t index = ( hal_time_stamp() + hal_get_gid() ) % (x_size * y_size);
	1154	uint32_t x = index / y_size;
	1155	uint32_t y = index % y_size;
	1156	cxy_t child_cxy = (x<<y_width) + y;
	1157
	1158	// create child inode TODO : define attr / mode / uid / gid
	1159	uint32_t attr = 0;
	1160	uint32_t mode = 0;
	1161	uint32_t uid = 0;
	1162	uint32_t gid = 0;
	1163
	1164	if( child_cxy == local_cxy ) // child cluster is the local cluster
	1165	{
	1166	error = vfs_inode_create( dentry_xp,
[23]	1167	fs_type,
	1168	inode_type,
[1]	1169	attr,
	1170	mode,
	1171	uid,
	1172	gid,
	1173	&inode_xp );
	1174	}
	1175	else // child cluster is remote
	1176	{
	1177	rpc_vfs_inode_create_client( child_cxy,
	1178	dentry_xp,
[23]	1179	fs_type,
	1180	inode_type,
[1]	1181	attr,
	1182	mode,
	1183	uid,
	1184	gid,
	1185	&inode_xp,
	1186	&error );
	1187	}
	1188
	1189	if( error )
	1190	{
	1191	printk("\n[ERROR] in %s : cannot create inode in cluster %x\n",
	1192	__FUNCTION__ , child_cxy );
	1193
	1194	vfs_dentry_t * dentry = (vfs_dentry_t *)GET_PTR( dentry_xp );
	1195	if( parent_cxy == local_cxy ) vfs_dentry_destroy( dentry );
	1196	else rpc_vfs_dentry_destroy_client( parent_cxy , dentry );
	1197	return error;
	1198	}
	1199
	1200	// success : return extended pointer on child inode
	1201	*child_xp = inode_xp;
	1202	return 0;
	1203
	1204	} // end vfs_add_child_in_parent()
	1205
	1206
[23]	1207
	1208
	1209	//////////////////////////////////////////////////////////////////////////////////////////
	1210	// Mapper related functions
	1211	//////////////////////////////////////////////////////////////////////////////////////////
	1212
	1213	////////////////////////////////////////////////
	1214	error_t vfs_move_page_to_mapper( page_t * page )
	1215	{
	1216	error_t error = 0;
	1217
	1218	assert( (page != NULL) , __FUNCTION__ , "page pointer is NULL\n" );
	1219
	1220	mapper_t * mapper = page->mapper;
	1221
	1222	assert( (mapper != NULL) , __FUNCTION__ , "no mapper for page\n" );
	1223
	1224	// get FS type
	1225	vfs_fs_type_t fs_type = mapper->inode->ctx->type;
	1226
	1227	// update mapper if permitted by file system type
	1228	if( fs_type == FS_TYPE_FATFS )
	1229	{
	1230	// get mapper lock in WRITE_MODE
	1231	rwlock_wr_lock( &mapper->lock );
	1232
	1233	error = fatfs_read_page( page );
	1234
	1235	// release mapper lock
	1236	rwlock_wr_unlock( &mapper->lock );
	1237	}
	1238	else if( fs_type == FS_TYPE_RAMFS )
	1239	{
	1240	assert( false , __FUNCTION__ , "should not be called for RAMFS\n" );
	1241	}
	1242	else if( fs_type == FS_TYPE_DEVFS )
	1243	{
	1244	assert( false , __FUNCTION__ , "should not be called for DEVFS\n" );
	1245	}
	1246	else
	1247	{
	1248	assert( false , __FUNCTION__ , "undefined file system type\n" );
	1249	}
	1250
	1251	return error;
	1252
	1253	} // end vfs_move_page_to_mapper()
	1254
	1255	//////////////////////////////////////////////////
	1256	error_t vfs_move_page_from_mapper( page_t * page )
	1257	{
	1258	error_t error = 0;
	1259
	1260	assert( (page != NULL) , __FUNCTION__ , "page pointer is NULL\n" );
	1261
	1262	mapper_t * mapper = page->mapper;
	1263
	1264	assert( (mapper != NULL) , __FUNCTION__ , "no mapper for page\n" );
	1265
	1266	// get FS type
	1267	vfs_fs_type_t fs_type = mapper->inode->ctx->type;
	1268
	1269	// update file system if permitted by file system type
	1270	if( fs_type == FS_TYPE_FATFS )
	1271	{
	1272	if( page_is_flag( page , PG_DIRTY ) )
	1273	{
	1274	// get mapper lock in READ_MODE
	1275	rwlock_rd_lock( &mapper->lock );
	1276
	1277	error = fatfs_write_page( page );
	1278
	1279	// release mapper lock from READ_MODE
	1280	rwlock_rd_unlock( &mapper->lock );
	1281
	1282	// clear dirty bit if success
	1283	if( error == 0 ) page_undo_dirty( page );
	1284	}
	1285	}
	1286	else if( fs_type == FS_TYPE_RAMFS )
	1287	{
	1288	assert( false , __FUNCTION__ , "should not be called for RAMFS\n" );
	1289	}
	1290	else if( fs_type == FS_TYPE_DEVFS )
	1291	{
	1292	assert( false , __FUNCTION__ , "should not be called for DEVFS\n" );
	1293	}
	1294	else
	1295	{
	1296	assert( false , __FUNCTION__ , "undefined file system type\n" );
	1297	}
	1298
	1299	return error;
	1300
	1301	} // end vfs_move_page_from_mapper()
	1302
	1303

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