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source: trunk/kernel/vfs/vfs.h @ 12

Last change on this file since 12 was 10, checked in by alain, 9 years ago
Merge all FS related files in one single directory.
File size: 47.4 KB

Rev	Line
[1]	1	/*
	2	* vfs.h - Virtual File System definition.
	3	*
	4	* Author Mohamed Lamine Karaoui (2015)
	5	* Alain Greiner (2016)
	6	*
	7	* Copyright (c) UPMC Sorbonne Universites
	8	*
	9	* This file is part of ALMOS-MKH.
	10	*
	11	* ALMOS-MKH is free software; you can redistribute it and/or modify it
	12	* under the terms of the GNU General Public License as published by
	13	* the Free Software Foundation; version 2.0 of the License.
	14	*
	15	* ALMOS-MKH is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with ALMOS-MKH; if not, write to the Free Software Foundation,
	22	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	23	*/
	24
	25	#ifndef _VFS_H_
	26	#define _VFS_H_
	27
	28	#include <almos_config.h>
	29	#include <hal_types.h>
	30	#include <hal_atomic.h>
	31	#include <remote_rwlock.h>
	32	#include <remote_spinlock.h>
	33	#include <spinlock.h>
	34	#include <list.h>
	35	#include <xlist.h>
	36	#include <slist.h>
	37	#include <bits.h>
	38	#include <xhtab.h>
	39	#include <errno.h>
	40	#include <metafs.h>
	41
	42	#include <fatfs.h>
	43	#include <ramfs.h>
	44
	45	/** Forward declarations */
	46
	47	struct vfs_inode_s;
	48	struct vfs_dentry_t;
	49	struct vfs_ctx_t;
	50	struct vfs_file_ref_s;
	51	struct vfs_file_s;
	52
	53	struct vfs_inode_op_s;
	54	struct vfs_dentry_op_s;
	55	struct vfs_file_op_s;
	56	struct vfs_ctx_op_s;
	57
	58	struct vfs_lookup_cmd_s;
	59	struct vfs_lookup_rsp_s;
	60
	61	struct mapper_s;
	62	struct process_s;
	63	struct device_s;
	64	struct vseg_s;
	65
	66	/*********************************************************************************************
	67	* This defines the various Flags arguments for an open() or opendir() system call.
	68	********************************************************************************************/
	69
	70	#define VFS_O_APPEND 0x00080000
	71	#define VFS_O_RDONLY 0x00100000
	72	#define VFS_O_WRONLY 0x00200000
	73	#define VFS_O_RDWR 0x00300000
	74	#define VFS_O_CREATE 0x00400000
	75	#define VFS_O_EXCL 0x00800000
	76	#define VFS_O_TRUNC 0x01000000
	77	#define VFS_O_SYNC 0x08000000
	78
	79	/*********************************************************************************************
	80	* This defines the various types of command for an lseek() system call.
	81	********************************************************************************************/
	82
	83	#define VFS_SEEK_SET 0
	84	#define VFS_SEEK_CUR 1
	85	#define VFS_SEEK_END 2
	86
	87	/*********************************************************************************************
	88	* TODO : the following flags were defined in the vfs-params.h file...
	89	* ... and must be documented. [AG]
	90	********************************************************************************************/
	91
	92
	93	//////////////////////////////////////
	94	/// keep these flags compact ///
	95	//////////////////////////////////////
	96	#define VFS_REGFILE 0x0000000
	97	#define VFS_DIR 0x0000001
	98	#define VFS_FIFO 0x0000002
	99	#define VFS_DEV_CHR 0x0000004
	100	#define VFS_DEV_BLK 0x0000008
	101	#define VFS_DEV 0x000000C
	102	#define VFS_SOCK 0x0000010
	103	#define VFS_SYMLNK 0x0000020
	104	//////////////////////////////////////
	105
	106	#define VFS_RD_ONLY 0x0000040
	107	#define VFS_SYS 0x0000080
	108	#define VFS_ARCHIVE 0x0000100
	109	#define VFS_PIPE 0x0000200
	110
	111	#define VFS_IFMT 0x0170000
	112	#define VFS_IFSOCK 0x0140000
	113	#define VFS_IFLNK 0x0120000
	114	#define VFS_IFREG 0x0100000
	115	#define VFS_IFBLK 0x0060000
	116	#define VFS_IFDIR 0x0040000
	117	#define VFS_IFCHR 0x0020000
	118	#define VFS_IFIFO 0x0010000
	119
	120	#define VFS_ISUID 0x0004000
	121	#define VFS_ISGID 0x0002000
	122	#define VFS_ISVTX 0x0001000
	123
	124	#define VFS_IRWXU 0x0000700
	125	#define VFS_IRUSR 0x0000400
	126	#define VFS_IWUSR 0x0000200
	127	#define VFS_IXUSR 0x0000100
	128	#define VFS_IRWXG 0x0000070
	129	#define VFS_IRGRP 0x0000040
	130	#define VFS_IWGRP 0x0000020
	131	#define VFS_IXGRP 0x0000010
	132	#define VFS_IRWXO 0x0000007
	133	#define VFS_IROTH 0x0000004
	134	#define VFS_IWOTH 0x0000002
	135	#define VFS_IXOTH 0x0000001
	136
	137	#define VFS_IREAD VFS_IRUSR
	138	#define VFS_IWRITE VFS_IWUSR
	139	#define VFS_IEXEC VFS_IXUSR
	140
	141	#define VFS_SET(state,flag) (state) \|= (flag)
	142	#define VFS_IS(state,flag) (state) & (flag)
	143	#define VFS_CLEAR(state,flag) (state) &= ~(flag)
	144
	145
	146	/* Lookup flags */
	147	#define VFS_LOOKUP_FILE 0x1
	148	#define VFS_LOOKUP_LAST 0x2
	149	#define VFS_LOOKUP_OPEN 0x4
	150	#define VFS_LOOKUP_RESTART 0x8
	151	#define VFS_LOOKUP_RETRY 0x10
	152	#define VFS_LOOKUP_PARENT 0x20
	153	#define VFS_LOOKUP_HELD 0x40
	154
	155	/* Context flags*/
	156	#define VFS_FS_LOCAL 0x1
	157	#define VFS_FS_USE_MAPPER 0x2
	158
	159
	160
	161
	162	/******************************************************************************************
	163	* This structure define a VFS inode.
	164	* It contains an extended pointer on the parent dentry, and (for directory only)
	165	* an hash table xhtab refering all children dentries.
	166	* The <parent> inode is unique for a directory (not hard links for directories).
	167	* For a file, the parent field points to the first dentry who created this inode.
[10]	168	* Syncronisation:
	169	* - the main_lock (spinlock) is used during the inode tree traversal or for inode
	170	* modification (add/remove children).
	171	* - the data_lock (rwlock) is used during read/write accesses to the data stored
	172	* in the mapper.
	173	* - the mapper lock (rwlock) is only used during the radix tree traversal to return
	174	* to return the relevant page for red/write.
[1]	175	*****************************************************************************************/
	176
[10]	177	typedef enum
	178	{
	179	INODE_TYPE_NORMAL, /! file or directory /
	180	INODE_TYPE_PIPE, /! POSIX pipe /
	181	INODE_TYPE_SOCKET, /! POSIX socket /
	182	INODE_TYPE_DEV, /! peripheral channel /
	183	}
	184	vfs_inode_type_t;
	185
[1]	186	typedef enum
	187	{
	188	INODE_ATTR_DIRTY = 0x01,
	189	INODE_ATTR_DIR = 0x02,
	190	INODE_ATTR_INLOAD = 0x04,
	191	INODE_ATTR_NEW = 0x08,
	192	}
[10]	193	vfs_inode_attr_t;
[1]	194
	195	typedef struct vfs_inode_s
	196	{
	197	struct vfs_ctx_s * ctx; /! Rlocal pointer on FS context /
	198	uint32_t gc; /! generation counter /
	199	uint32_t inum; /! inode identifier (unique in file system) /
	200	uint32_t attr; /! inode attributes (see above) /
[10]	201	uint32_t type; /! inode type (see above) /
[1]	202	uint32_t size; /! number of bytes /
	203	uint32_t links; /! number of alias dentry /
	204	uid_t uid; /! user owner identifier /
	205	gid_t gid; /! group owner identifier /
	206	uint32_t mode; /! access mode /
	207	uint32_t refcount; /! reference counter (all pointers) /
	208	xptr_t parent_xp; /! extended pointer on parent dentry /
	209	xhtab_t children; /! embedded htab of dir entries (for dir type) /
[10]	210	remote_rwlock_t data_lock; /! protect read/write to data and to size /
	211	remote_spinlock_t main_lock; /! protect inode tree traversal and modifs /
[1]	212	xlist_entry_t xlist; /! member of set of inodes in same cluster /
	213	xlist_entry_t wait_root; /! root of threads waiting on this inode /
	214	struct vfs_inode_op_s * op; /! TODO ??? /
	215	struct mapper_s * mapper; /! associated file cache /
	216	void * extend; /! FS specific inode extension /
	217	}
	218	vfs_inode_t;
	219
	220	/******************************************************************************************
	221	* This structure defines a directory entry.
	222	* A dentry contains the name of a remote file/dir, an extended pointer on the
	223	* inode representing this file/dir, and a local pointer on the inode representing
	224	* the parent directory.
	225	*****************************************************************************************/
	226
	227	typedef struct vfs_dentry_s
	228	{
	229	struct vfs_ctx_s * ctx; /! local pointer on FS context /
	230	char name[CONFIG_VFS_MAX_NAME_LENGTH];
	231	uint32_t length; /! name length (bytes) /
	232	uint32_t refcount; /! reference counter (all pointers) /
	233	struct vfs_inode_s * parent; /! local pointer on parent inode /
	234	xptr_t child_xp; /! extended pointer on child inode /
	235	xlist_entry_t xlist; /! member of xlist of dentries with same key /
	236	struct vfs_dentry_op_s * op; /! TODO /
	237	void * extend; /! FS specific extension /
	238	}
	239	vfs_dentry_t;
	240
	241	/******************************************************************************************
	242	* This structure describes an open file/directory for a given process.
	243	* It is not replicated, and is dynamically allocated in the cluster that contains
	244	* the inode, when a thread makes an open() or opendir() system call.
	245	*****************************************************************************************/
	246
	247
	248	typedef enum
	249	{
[10]	250	FD_ATTR_READ_ENABLE = 0x01, /! read access possible /
	251	FD_ATTR_WRITE_ENABLE = 0x02, /! write access possible /
	252	FD_ATTR_APPEND = 0x04, /! append on each write /
	253	FD_ATTR_CLOSE_EXEC = 0x08, /! close file on exec /
	254	FD_ATTR_SYNC = 0x10, /! synchronise FS on each write /
	255	FD_ATTR_IS_DIR = 0x20, /! this is a directory /
[1]	256	}
	257	vfs_fd_attr_t;
	258
	259	typedef struct vfs_file_s
	260	{
	261	uint32_t gc; /! generation counter /
	262	uint32_t type; /! see above /
	263	uint32_t attr; /! see above /
	264	uint32_t offset; /! seek position in file /
	265	uint32_t refcount; /! all pointers on this file /
	266	remote_rwlock_t lock; /! protect offset modifications /
	267	struct mapper_s * mapper; /! associated file cache /
	268	struct vfs_inode_s * inode; /! local pointer on associated inode /
	269	struct vfs_ctx_s * ctx; /! file system features /
	270	struct vfs_file_op_s * op; /! local set of function pointers /
	271	}
	272	vfs_file_t;
	273
	274	/******************************************************************************************
	275	* This structure defines informations common to all inodes and dentries
	276	* of a given file system. As it is declared a global variable in the kdata segment,
	277	* it is replicated in all clusters and handled as private by each OS intance.
	278	*****************************************************************************************/
	279
	280	typedef enum
	281	{
	282	FS_TYPE_SYSFS = 0,
	283	FS_TYPE_DEVFS = 1,
	284	FS_TYPE_FATFS = 2,
	285	FS_TYPE_RAMFS = 3,
	286
	287	FS_TYPES_NR = 4,
	288	}
	289	vfs_types_t;
	290
[10]	291	typedef enum
	292	{
	293	CTX_ATTR_READ_ONLY = 0x01, /! read access possible /
	294	CTX_ATTR_SYNC = 0x10, /! synchronise FS on each write /
	295	}
	296	vfs_ctx_attr_t;
	297
[1]	298	typedef struct vfs_ctx_s
	299	{
	300	uint32_t type; /! File System type /
[10]	301	uint32_t attr; /! global attributes for all files in FS /
[1]	302	uint32_t count; /! number of clusters /
	303	uint32_t blksize; /! cluster size /
	304	xptr_t ioc_xp; /! extended pointer on IOC device /
	305	xptr_t root_xp; /! extended pointer on root inode /
	306
	307	spinlock_t lock; /! lock protecting inum allocator /
	308	BITMAP( inum , CONFIG_VFS_MAX_INODES ); /! inum allocator /
	309
	310	void * extend; /! FS specific context extension /
	311	}
	312	vfs_ctx_t;
	313
	314	/******************************************************************************************
	315	* This structure define the informations associated to a given file descriptor,
	316	* that are returned by the vfs_stat() function.
	317	*****************************************************************************************/
	318
	319	typedef struct vfs_stat_s
	320	{
	321	uint32_t dev; /! ID of device containing file /
	322	uint32_t ino; /! inode number /
	323	uint32_t mode; /! protection /
	324	uint32_t nlink; /! number of hard links /
	325	uint32_t uid; /! user ID of owner /
	326	uint32_t gid; /! group ID of owner /
	327	uint32_t rdev; /! device ID (if special file) /
	328	uint64_t size; /! total size, in bytes /
	329	uint32_t blksize; /! blocksize for file system I/O /
	330	uint32_t blocks; /! number of 512B blocks allocated /
	331	uint64_t atime; /! time of last access /
	332	uint64_t mtime; /! time of last modification /
	333	uint64_t ctime; /! time of last status change /
	334	}
	335	vfs_stat_t;
	336
	337
	338
	339
	340
	341
	342	/******************************************************************************************
	343	* This structure defines the set of operations that can be done on a VFS context.
	344	* TODO A quoi cela sert-il ? [AG]
	345	*****************************************************************************************/
	346
	347	typedef error_t (vfs_create_context_t) ( vfs_ctx_t * context );
	348	typedef error_t (vfs_destroy_context_t) ( vfs_ctx_t * context );
	349	typedef error_t (vfs_read_root_t) ( vfs_ctx_t * context , vfs_inode_t * root );
	350	typedef error_t (vfs_reply_root_t) ( vfs_ctx_t * context , vfs_inode_t * root );
	351	typedef error_t (vfs_write_root_t) ( vfs_ctx_t * context , vfs_inode_t * root );
	352
	353	struct vfs_ctx_op_s
	354	{
	355	vfs_create_context_t * create; /! allocate memory and initialize a context /
	356	vfs_destroy_context_t * destroy; /! release memory allocated to a context /
	357	vfs_read_root_t * read_root; /! TODO /
	358	vfs_reply_root_t * repli_root; /! TODO /
	359	vfs_write_root_t * write_root; /! TODO /
	360	}
	361	vfs_ctx_op_t;
	362
	363	/******************************************************************************************
	364	* This structure defines the set of operations that can be done on a VFS inode.
	365	* TODO A quoi cela sert-il ? [AG]
	366	*****************************************************************************************/
	367
	368	typedef error_t (vfs_init_inode_t) ( vfs_inode_t * inode );
	369	typedef error_t (vfs_create_inode_t) ( vfs_inode_t * parent , vfs_dentry_t * dentry );
	370	typedef error_t (vfs_lookup_inode_t) ( vfs_inode_t * parent , vfs_dentry_t * dentry );
	371	typedef error_t (vfs_write_inode_t) ( vfs_inode_t * inode );
	372	typedef error_t (vfs_release_inode_t) ( vfs_inode_t * inode );
	373	typedef error_t (vfs_unlink_inode_t) ( vfs_inode_t * parent , vfs_dentry_t * dentry , uint32_t flags );
	374	typedef error_t (vfs_stat_inode_t) ( vfs_inode_t * inode );
	375	typedef error_t (vfs_trunc_inode_t) ( vfs_inode_t * inode );
	376	typedef error_t (vfs_delete_inode_t) ( vfs_inode_t * inode );
	377
	378	typedef struct vfs_inode_op_s
	379	{
	380	vfs_init_inode_t * init; /! initialise inode from scratch /
	381	vfs_create_inode_t * create; /! allocate memory for one inode /
	382	vfs_lookup_inode_t * lookup; /! get one directory entry by name /
	383	vfs_write_inode_t * write; /! update the device from the inode /
	384	vfs_release_inode_t * release; /! reset one inode and release associated objects /
	385	vfs_unlink_inode_t * unlink; /! unlink a directory entry from parent inode /
	386	vfs_delete_inode_t * delete; /! release memory allocated to inode when count = 0 /
	387	vfs_stat_inode_t * stat; /! TODO /
	388	vfs_trunc_inode_t * trunc; /! change the size of a file /
	389	}
	390	vfs_inode_op_t;
	391
	392	/******************************************************************************************
	393	* This structure defines the set of operations that can be done on a VFS dentry.
	394	* TODO A quoi cela sert-il ? [AG]
	395	*****************************************************************************************/
	396
	397	typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
	398
	399	typedef struct vfs_dentry_op_s
	400	{
	401	vfs_compare_dentry_t * compare;
	402	}
	403	vfs_dentry_op_t;
	404
	405	/******************************************************************************************
	406	* This structure defines the set of operations that can be done on a VFS file.
	407	* TODO A quoi cela sert-il ? [AG]
	408	*****************************************************************************************/
	409
	410	typedef error_t (vfs_open_file_t) ( vfs_file_t * file , void * priv );
	411	typedef error_t (vfs_read_file_t) ( vfs_file_t * file , char * buffer );
	412	typedef error_t (vfs_write_file_t) ( vfs_file_t * file , char * buffer );
	413	typedef error_t (vfs_lseek_file_t) ( vfs_file_t * file );
	414	typedef error_t (vfs_close_file_t) ( vfs_file_t * file );
	415	typedef error_t (vfs_release_file_t) ( vfs_file_t * file );
	416	typedef error_t (vfs_read_dir_t) ( vfs_file_t * file );
	417	typedef error_t (vfs_mmap_file_t) ( vfs_file_t * file , struct vseg_s * vseg );
	418	typedef error_t (vfs_munmap_file_t) ( vfs_file_t * file , struct vseg_s * vseg );
	419
	420	typedef struct vfs_file_op_s
	421	{
	422	vfs_open_file_t * open;
	423	vfs_read_file_t * read;
	424	vfs_write_file_t * write;
	425	vfs_lseek_file_t * lseek;
	426	vfs_read_dir_t * readdir;
	427	vfs_close_file_t * close;
	428	vfs_release_file_t * release;
	429	vfs_mmap_file_t * mmap;
	430	vfs_munmap_file_t * munmap;
	431	}
	432	vfs_file_op_t;
	433
	434
	435
	436
	437
	438
	439	/*****************************************************************************************/
	440	/****************** VFS global functions *********************************************/
	441	/*****************************************************************************************/
	442
	443	/******************************************************************************************
	444	* This function initializes the Virtual File System.
	445	*****************************************************************************************/
	446	void vfs_init();
	447
	448	/******************************************************************************************
	449	* This function mount a given file system type for a given process.
	450	*****************************************************************************************/
	451	error_t vfs_mount_fs_root( struct device_s * device,
	452	uint32_t fs_type,
	453	struct process_s * process );
	454
	455
	456	/*****************************************************************************************/
	457	/***************** FS Context related functions **************************************/
	458	/*****************************************************************************************/
	459
	460	/******************************************************************************************
	461	* This function allocates an inode identifier from the local cluster inum allocator.
	462	* The inum respects a fixed format:
	463	* - the 16 MSB bits contain the cluster identifier : cxy
	464	* - the 16 LSB bits contains the local inode identifier : lid
	465	******************************************************************************************
	466	* @ ctx : local pointer on file system context.
	467	* @ inum : [ou] buffer for allocated inode identifier.
	468	* @ return 0 if success / return non-zero if error.
	469	*****************************************************************************************/
	470	error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
	471	uint32_t * inum );
	472
	473	/******************************************************************************************
	474	* This function release an inode identifier.
	475	******************************************************************************************
	476	* @ ctx : local pointer on file system context.
	477	* @ inum : released inode identifier.
	478	*****************************************************************************************/
	479	void vfs_ctx_inum_release( vfs_ctx_t * ctx,
	480	uint32_t inum );
	481
	482
	483
	484	/*****************************************************************************************/
	485	/********************** File Descriptor related functions ****************************/
	486	/*****************************************************************************************/
	487
	488	/******************************************************************************************
	489	* This function allocates memory and initializes a new local file descriptor.
	490	* It must be executed in the owner cluster containing the inode.
	491	* If the client thread is not running in the owner cluster, it must use the
	492	* rpc_vfs_file_create_client() function.
	493	******************************************************************************************
	494	* @ inode_xp : extended pointer on associated inode.
	495	* @ type : file descriptor type.
	496	* @ attr : file descriptor attributes.
	497	* @ file_xp : [out] buffer for extended pointer on created file descriptor.
	498	* @ return 0 if success / return ENOMEM if error.
	499	*****************************************************************************************/
	500	error_t vfs_file_create( xptr_t inode_xp,
	501	uint32_t type,
	502	uint32_t attr,
	503	xptr_t * file_xp );
	504
	505	/******************************************************************************************
	506	* This function releases memory allocated to a local file descriptor.
	507	* It must be executed by a thread running in the cluster containing the inode,
	508	* and the file refcount must be zero.
	509	* If the client thread is not running in the owner cluster, it must use the
	510	* rpc_vfs_file_destroy_client() function.
	511	******************************************************************************************
	512	* @ file_xp : extended pointer on file descriptor.
	513	*****************************************************************************************/
	514	void vfs_file_destroy( xptr_t file_xp );
	515
	516
	517	/******************************************************************************************
	518	* These functions increment (resp. decrement) the count field in a remote file
	519	* descriptor, using a remote_atomic access.
	520	*****************************************************************************************/
	521	void vfs_file_count_up ( xptr_t file_xp );
	522	void vfs_file_count_down( xptr_t file_xp );
	523
	524
	525
	526	/*****************************************************************************************/
	527	/******************* Inode related functions *****************************************/
	528	/*****************************************************************************************/
	529
	530	/******************************************************************************************
	531	* This function allocates memory from local cluster for an inode descriptor and the
	532	* associated mapper. It initialise these descriptors from arguments values.
	533	* The parent dentry must have been previously created.
	534	* If the client thread is not running in the cluster containing this inode,
	535	* it must use the rpc_vfs_inode_create_client() function.
	536	******************************************************************************************
	537	* @ dentry_xp : extended pointer on associated dentry (in parent inode cluster).
	538	* @ type : file system type.
	539	* @ attr : inode attributes.
	540	* @ mode : inode access mode.
	541	* @ uid : user owner ID.
	542	* @ gid : group owner ID.
	543	* @ inode_xp : [out] buffer for extended pointer on created inode.
	544	* # return 0 if success / return ENOMEM or EINVAL if error.
	545	*****************************************************************************************/
	546	error_t vfs_inode_create( xptr_t dentry_xp,
	547	uint32_t type,
	548	uint32_t attr,
	549	uint32_t mode,
	550	uid_t uid,
	551	gid_t gid,
	552	xptr_t * inode_xp );
	553
	554	/******************************************************************************************
	555	* This function releases memory allocated to an inode descriptor.
	556	* It must be executed by a thread running in the cluster containing the inode,
	557	* and the inode refcount must be zero.
	558	* If the client thread is not running in the owner cluster, it must use the
	559	* rpc_vfs_inode_destroy_client() function.
	560	******************************************************************************************
	561	* @ inode : local pointer on inode descriptor.
	562	*****************************************************************************************/
	563	void vfs_inode_destroy( vfs_inode_t * inode );
	564
	565	/******************************************************************************************
	566	* This function atomically increment the inode refcount.
	567	* It can be called by any thread running in any cluster.
	568	*****************************************************************************************/
	569	void vfs_inode_remote_up( xptr_t inode_xp );
	570
	571	/******************************************************************************************
	572	* This function atomically decrement the inode refcount.
	573	* It can be called by any thread running in any cluster.
	574	*****************************************************************************************/
	575	void vfs_inode_remote_down( xptr_t inode_xp );
	576
	577	/******************************************************************************************
	578	* This function returns the <size> of a file/dir from a remote inode,
	579	* taking the remote_rwlock protecting <size> in READ_MODE.
	580	*****************************************************************************************
	581	* @ inode_xp : extended pointer on the remote inode.
	582	* @ return the current size.
	583	*****************************************************************************************/
	584	uint32_t vfs_inode_get_size( xptr_t inode_xp );
	585
	586	/******************************************************************************************
	587	* This function set the <size> of a file/dir to a remote inode,
	588	* taking the remote_rwlock protecting <size> in WRITE_MODE.
	589	*****************************************************************************************
	590	* @ inode_xp : extended pointer on the remote inode.
	591	* @ size : value to be written.
	592	*****************************************************************************************/
	593	void vfs_inode_set_size( xptr_t inode_xp,
	594	uint32_t size );
	595
	596	/******************************************************************************************
	597	* This function takes the main lock of a remote inode.
	598	* This lock protect all inode fiels, including the children dentries.
	599	*****************************************************************************************
	600	* @ inode_xp : extended pointer on the remote inode.
	601	*****************************************************************************************/
	602	void vfs_inode_remote_lock( xptr_t inode_xp );
	603
	604	/******************************************************************************************
	605	* This function releases the main lock of a remote inode.
	606	* This lock protect all inode fiels, including the children dentries.
	607	*****************************************************************************************
	608	* @ inode_xp : extended pointer on the remote inode.
	609	*****************************************************************************************/
	610	void vfs_inode_remote_unlock( xptr_t inode_xp );
	611
	612
	613
	614
	615	/******************************************************************************************
	616	* This function TODO
	617	*****************************************************************************************/
	618	error_t vfs_inode_hold( vfs_inode_t * inode,
	619	uint32_t gc );
	620
	621	/******************************************************************************************
	622	* This function TODO
	623	*****************************************************************************************/
	624	error_t vfs_inode_trunc( vfs_inode_t * inode );
	625
	626	/******************************************************************************************
	627	* This function TODO
	628	*****************************************************************************************/
	629	error_t vfs_inode_link( vfs_inode_t * inode,
	630	uint32_t igc );
	631
	632	/******************************************************************************************
	633	* This function TODO
	634	*****************************************************************************************/
	635	error_t vfs_inode_unlink( vfs_inode_t * inode );
	636
	637	/******************************************************************************************
	638	* This function TODO
	639	*****************************************************************************************/
	640	error_t vfs_inode_stat( vfs_inode_t * inode,
	641	uint32_t inum );
	642
	643	/******************************************************************************************
	644	* This function TODO
	645	*****************************************************************************************/
	646	error_t vfs_icache_del( vfs_inode_t * inode );
	647
	648
	649	/******************************************************************************************
	650	* This function TODO Pourquoi 2 arguments ?
	651	*****************************************************************************************/
	652	error_t vfs_stat_inode( vfs_inode_t * inode,
	653	uint32_t inum );
	654
	655
	656	/*****************************************************************************************/
	657	/*************** Dentry related functions ********************************************/
	658	/*****************************************************************************************/
	659
	660	/******************************************************************************************
	661	* This function allocates memory from local cluster for a dentry descriptor,
	662	* initialises it from arguments values, and returns the extended pointer on dentry.
	663	* The inode field is not initialized, because the inode does not exist yet.
	664	* If the client thread is not running in the target cluster for this inode,
	665	* it must use the rpc_dentry_create_client() function.
	666	******************************************************************************************
	667	* @ type : file system type.
	668	* @ name : directory entry file/dir name.
	669	* @ parent : local pointer on parent inode.
	670	* @ dentry_xp : [out] buffer for extended pointer on created inode.
	671	* @ return 0 if success / return ENOMEM or EINVAL if error.
	672	*****************************************************************************************/
	673	error_t vfs_dentry_create( uint32_t type,
	674	char * name,
	675	vfs_inode_t * parent,
	676	xptr_t * dentry_xp );
	677
	678	/******************************************************************************************
	679	* This function releases memory allocated to a dentry descriptor.
	680	* It must be executed by a thread running in the cluster containing the dentry,
	681	* and the dentry refcount must be zero.
	682	* If the client thread is not running in the owner cluster, it must use the
	683	* rpc_dentry_destroy_client() function.
	684	******************************************************************************************
	685	* @ dentry : local pointer on dentry descriptor.
	686	*****************************************************************************************/
	687	void vfs_dentry_destroy( vfs_dentry_t * dentry );
	688
	689	/******************************************************************************************
	690	* This function atomically increment the dentry refcount.
	691	* It can be called by any thread running in any cluster.
	692	*****************************************************************************************/
	693	void vfs_dentry_remote_up( xptr_t dentry_xp );
	694
	695	/******************************************************************************************
	696	* This function atomically decrement the dentry refcount.
	697	* It can be called by any thread running in any cluster.
	698	*****************************************************************************************/
	699	void vfs_dentry_remote_down( xptr_t dentry_xp );
	700
	701
	702	/*****************************************************************************************/
	703	/* Inode-Tree related functions */
	704	/*****************************************************************************************/
	705
	706	/******************************************************************************************
	707	* This function returns in a kernel buffer allocated by the caller function,
	708	* the pathname of a file/dir identified by an extended pointer on the inode.
	709	* It traverse the Inode Tree from the target node to the root.
	710	* It can be called by any thread running in any cluster.
	711	******************************************************************************************
	712	* @ inode_xp : pointer on inode descriptor.
	713	* @ buffer : kernel buffer for pathname (must be allocated by caller).
	714	* @ size : max number of characters in buffer.
	715	* @ return 0 if success / return EINVAL if buffer too small.
	716	*****************************************************************************************/
	717	error_t vfs_get_path( xptr_t inode_xp,
	718	char * buffer,
	719	uint32_t max_size );
	720
	721	/******************************************************************************************
	722	* This function takes a pathname (absolute or relative to cwd) and returns an extended
	723	* pointer on the associated inode, and an extended pointer on the inode context.
	724	* If a given name in the path is not found in the inode tree, it try to load the missing
	725	* dentry/inode couple, from informations found in the parent directory.
	726	* If this directory entry does not exist on device, it returns an error.
	727	******************************************************************************************
	728	* @ cwd_xp : extended pointer on current directory (for relative path).
	729	* @ pathname : path in kernel space (can be relative or absolute).
	730	* @ client_uid : client thread user ID (for checking).
	731	* @ client_gid : client thread group ID (for checking).
	732	* @ inode_xp : [out] buffer for extended pointer on inode.
	733	* @ ctx_xp : [out] buffer for extended pointer on inode context.
	734	* @ return 0 if success / ENOENT if inode not found / EACCES if permissopn denied
	735	*****************************************************************************************/
	736	error_t vfs_lookup( xptr_t cwd_xp,
	737	char * pathname,
	738	uint32_t client_uid,
	739	uint32_t client_gid,
	740	xptr_t * inode_xp,
	741	xptr_t * ctx_xp );
	742
	743	/******************************************************************************************
	744	* This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
	745	* It can be executed by any thread running in any cluster, as this function
	746	* uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
	747	* - The dentry is created in the cluster containing the existing <parent_xp> inode.
	748	* - the child inode and its associated mapper are created in a randomly selected cluster.
	749	* - The dentry name is defined by the <name> argument.
	750	******************************************************************************************
	751	* @ type : new inode type
	752	* @ parent_xp : extended pointer on parent inode.
	753	* @ name : new directory entry name.
	754	* @ child_xp : [out] buffer for extended pointer on child inode.
	755	* @ return 0 if success / ENOENT if entry not found in parent directory
	756	*****************************************************************************************/
	757	error_t vfs_add_child_in_parent( uint32_t type,
	758	xptr_t parent_xp,
	759	char * name,
	760	xptr_t * child_xp );
	761
	762	/******************************************************************************************
	763	* TODO
	764	******************************************************************************************
	765	* @ child_xp : extended pointer on removed inode.
	766	*****************************************************************************************/
	767	error_t vfs_remove_child_from_parent( xptr_t child_xp );
	768
	769	/*****************************************************************************************/
	770	/********************** File related functions ***************************************/
	771	/*****************************************************************************************/
	772
	773	/******************************************************************************************
	774	* This function allocates a vfs_file_t structure in the cluster containing the inode
	775	* associated to the requested file, initializes it, and returns an extended pointer
	776	* on this remote open file descriptor.
	777	* The pathname can be relative to current directory or absolute.
	778	* If the inode does not exist in the inode cache, it try to find file on the mounted
	779	* device, and creates an inode on a pseudo randomly selected cluster if found.
	780	* It the requested file does not exist on device, it creates a new inode if the
	781	* O_CREAT flag is set and return an error otherwise.
	782	******************************************************************************************
	783	* @ cwd_xp : extended pointer on current directory file descriptor (for relative path).
	784	* @ path : file pathname (absolute or relative to current directory).
	785	* @ flags : O_RDONLY, O_WRONLY, O_CREATE etc...
	786	* @ file_xp : [out] buffer for extended pointer on created remote file descriptor.
	787	* @ return 0 if success / return non-zero if error.
	788	*****************************************************************************************/
	789	error_t vfs_open( xptr_t cwd_xp,
	790	char * path,
	791	uint32_t flags,
	792	xptr_t * file_xp );
	793
	794	/******************************************************************************************
	795	* This function moves <size> bytes from the file identified by the open file descriptor
	796	* <file_xp> to the local kernel <buffer> , taken into account the offset in <file_xp>.
	797	******************************************************************************************
	798	* @ file_xp : extended pointer on the remote open file descriptor.
	799	* @ buffer : local pointer on destination kernel buffer.
	800	* @ size : requested number of bytes from offset.
	801	* @ returns number of bytes actually transfered / 0 if EOF / -1 if error.
	802	*****************************************************************************************/
	803	uint32_t vfs_read( xptr_t file_xp,
	804	void * buffer,
	805	uint32_t size );
	806
	807	/******************************************************************************************
	808	* This function moves <size> bytes from the local kernel <buffer> to the open file
	809	* descriptor <file_xp>, taken into account the offset defined in <file_xp>.
	810	******************************************************************************************
	811	* @ file_xp : extended pointer on the remote open file descriptor.
	812	* @ buffer : local pointer on source kernel buffer.
	813	* @ size : requested number of bytes to be written from offset.
	814	* @ returns number of bytes actually transfered / -1 if error.
	815	*****************************************************************************************/
	816	uint32_t vfs_write( xptr_t file_xp,
	817	void * buffer,
	818	uint32_t size );
	819
	820	/******************************************************************************************
	821	* This function set a new value in the offset of the open file descriptor <file_xp>.
	822	* This value depends on the <whence> argument:
	823	* - if VFS_SEEK_SET, new value is <offset>
	824	* - if VFS_SEEK_CUR, new value is current_offset + <offset>
	825	* - if VFS_SEEK_END, new value is file_size + <offset>
	826	******************************************************************************************
	827	* @ file_xp : extended pointer on the remote open file descriptor.
	828	* @ offset : local pointer on source kernel buffer.
	829	* @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
	830	* @ new_offset : [out] buffer for new offset value.
	831	* @ returns 0 if success / -1 if error.
	832	*****************************************************************************************/
	833	error_t vfs_lseek( xptr_t file_xp,
	834	uint32_t offset,
	835	uint32_t whence,
	836	uint32_t * new_offset );
	837
	838	/******************************************************************************************
	839	* This function close an open file descriptor.
	840	******************************************************************************************
	841	* @ file_xp : extended pointer on the file descriptor.
	842	* @ refcount : number of references after close.
	843	* @ return 0 if success / return -1 if error
	844	*****************************************************************************************/
	845	error_t vfs_close( xptr_t file_xp,
	846	uint32_t * refcount );
	847
	848	/******************************************************************************************
	849	* This function remove from the file system a directory entry identified by its pathname.
	850	* The pathname can be relative to current directory or absolute.
	851	******************************************************************************************
	852	* @ cwd_xp : extended pointer on the current directory file descriptor.
	853	* @ path : pathname (absolute or relative to current directory).
	854	*****************************************************************************************/
	855	error_t vfs_unlink( xptr_t cwd_xp,
	856	char * path );
	857
	858	/******************************************************************************************
	859	* This function returns in the <ustat> structure various informations on the file TODO
	860	*****************************************************************************************/
	861	error_t vfs_stat( xptr_t file_xp,
	862	vfs_stat_t * ustat );
	863
	864
	865
	866
	867	/*****************************************************************************************/
	868	/********************** Directory related functions **********************************/
	869	/*****************************************************************************************/
	870
	871	/******************************************************************************************
	872	* This function TODO
	873	*****************************************************************************************/
	874	error_t vfs_opendir( xptr_t cwd_xp,
	875	char * path,
	876	uint32_t flags,
	877	xptr_t file_xp );
	878
	879	/******************************************************************************************
	880	* This function TODO
	881	* fat32_readdir need cleaning
	882	*****************************************************************************************/
	883	error_t vfs_readdir( xptr_t file_xp,
	884	char * path );
	885
	886	/******************************************************************************************
	887	* This function TODO
	888	*****************************************************************************************/
	889	error_t vfs_mkdir( xptr_t file_xp,
	890	char * path,
	891	uint32_t mode );
	892
	893	/******************************************************************************************
	894	* This function remove a directory from the file system.
	895	*****************************************************************************************/
	896	error_t vfs_rmdir( xptr_t file_xp,
	897	char * path );
	898
	899	/******************************************************************************************
	900	* This function TODO
	901	*****************************************************************************************/
	902	error_t vfs_chdir( char * pathname,
	903	xptr_t cwd_xp );
	904
	905	/******************************************************************************************
	906	* This function TODO
	907	*****************************************************************************************/
	908	error_t vfs_chmod( char * pathname,
	909	vfs_file_t * cwd,
	910	uint32_t mode );
	911
	912	/******************************************************************************************
	913	* This function TODO
	914	*****************************************************************************************/
	915	error_t vfs_closedir( xptr_t file_xp,
	916	uint32_t * refcount );
	917
	918
	919
	920
	921	/*****************************************************************************************/
	922	/***************** Pipe related functions *******************************************/
	923	/*****************************************************************************************/
	924
	925	/******************************************************************************************
	926	* This function TODO ???
	927	*****************************************************************************************/
	928	error_t vfs_pipe( xptr_t pipefd[2] );
	929
	930	/******************************************************************************************
	931	* This function TODO
	932	*****************************************************************************************/
	933	error_t vfs_mkfifo( xptr_t cwd_xp,
	934	char * path,
	935	uint32_t mode );
	936
	937
	938
	939
	940	#endif /* _VFS_H_ */

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