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source: trunk/kernel/vfs/vfs.h @ 197

Last change on this file since 197 was 188, checked in by alain, 7 years ago
Redefine the PIC device API.
File size: 51.4 KB

Rev	Line
[1]	1	/*
	2	* vfs.h - Virtual File System definition.
	3	*
[23]	4	* Author Mohamed Lamine Karaoui (2014,2015)
	5	* Alain Greiner (2016,2017)
[1]	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
[14]	28	#include <kernel_config.h>
[1]	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>
[23]	44	#include <devfs.h>
[1]	45
	46	/** Forward declarations */
	47
	48	struct vfs_inode_s;
	49	struct vfs_dentry_t;
	50	struct vfs_ctx_t;
	51	struct vfs_file_ref_s;
	52	struct vfs_file_s;
	53
	54	struct vfs_inode_op_s;
	55	struct vfs_dentry_op_s;
	56	struct vfs_file_op_s;
	57	struct vfs_ctx_op_s;
	58
	59	struct vfs_lookup_cmd_s;
	60	struct vfs_lookup_rsp_s;
	61
	62	struct mapper_s;
	63	struct process_s;
	64	struct device_s;
	65	struct vseg_s;
[23]	66	struct page_s;
[1]	67
	68
[23]	69	/******************************************************************************************
	70	* These flags are used to define the working mode of the vfs_lookup() function.
	71	*****************************************************************************************/
[1]	72
[23]	73	#define VFS_LOOKUP_DIR 0x01 /* the searched inode is a directory */
	74	#define VFS_LOOKUP_OPEN 0x02 /* the search is for an open/opendir */
	75	#define VFS_LOOKUP_PARENT 0x04 /* return the parent inode (not the inode itself) */
	76	#define VFS_LOOKUP_CREATE 0x10 /* file must be created if missing */
	77	#define VFS_LOOKUP_EXCL 0x20 /* file cannot previously exist */
[1]	78
[23]	79	/******************************************************************************************
	80	* This define the masks for the POSIX access rights to inodes
	81	*****************************************************************************************/
[1]	82
[23]	83	#define VFS_ISUID 0x0004000
	84	#define VFS_ISGID 0x0002000
	85	#define VFS_ISVTX 0x0001000
[1]	86
	87	#define VFS_IRWXU 0x0000700
	88	#define VFS_IRUSR 0x0000400
	89	#define VFS_IWUSR 0x0000200
	90	#define VFS_IXUSR 0x0000100
[23]	91
[1]	92	#define VFS_IRWXG 0x0000070
	93	#define VFS_IRGRP 0x0000040
	94	#define VFS_IWGRP 0x0000020
	95	#define VFS_IXGRP 0x0000010
[23]	96
[1]	97	#define VFS_IRWXO 0x0000007
	98	#define VFS_IROTH 0x0000004
	99	#define VFS_IWOTH 0x0000002
	100	#define VFS_IXOTH 0x0000001
	101
	102	#define VFS_IREAD VFS_IRUSR
	103	#define VFS_IWRITE VFS_IWUSR
	104	#define VFS_IEXEC VFS_IXUSR
	105
	106
[23]	107	/******************************************************************************************
	108	* This structure defines informations common to all inodes and dentries
	109	* of a given file system. As it is declared a global variable in the kdata segment,
	110	* it is replicated in all clusters and handled as private by each OS intance.
	111	*****************************************************************************************/
[1]	112
[23]	113	typedef enum
	114	{
	115	FS_TYPE_DEVFS = 0,
	116	FS_TYPE_FATFS = 1,
	117	FS_TYPE_RAMFS = 2,
	118
	119	FS_TYPES_NR = 3,
	120	}
	121	vfs_fs_type_t;
[1]	122
[23]	123	typedef enum
	124	{
	125	CTX_ATTR_READ_ONLY = 0x01, /! write access prohibited /
	126	CTX_ATTR_SYNC = 0x10, /! synchronise FS on each write /
	127	}
	128	vfs_ctx_attr_t;
[1]	129
[23]	130	typedef struct vfs_ctx_s
	131	{
	132	vfs_fs_type_t type; /! File System type /
	133	uint32_t attr; /! global attributes for all files in FS /
[188]	134	uint32_t total_clusters; /! total number of clusters on device /
	135	uint32_t cluster_size; /! cluster size on device (bytes) /
	136	xptr_t vfs_root_xp; /! extended pointer on VFS root inode /
[23]	137	spinlock_t lock; /! lock protecting inum allocator /
	138	uint32_t bitmap[BITMAP_SIZE(CONFIG_VFS_MAX_INODES)]; /* inum allocator */
	139	void * extend; /! FS specific context extension /
	140	}
	141	vfs_ctx_t;
[1]	142
	143	/******************************************************************************************
	144	* This structure define a VFS inode.
	145	* It contains an extended pointer on the parent dentry, and (for directory only)
	146	* an hash table xhtab refering all children dentries.
	147	* The <parent> inode is unique for a directory (not hard links for directories).
	148	* For a file, the parent field points to the first dentry who created this inode.
[23]	149	* Syncrhonisation:
[10]	150	* - the main_lock (spinlock) is used during the inode tree traversal or for inode
	151	* modification (add/remove children).
	152	* - the data_lock (rwlock) is used during read/write accesses to the data stored
	153	* in the mapper.
	154	* - the mapper lock (rwlock) is only used during the radix tree traversal to return
[23]	155	* the relevant page for read/write.
[1]	156	*****************************************************************************************/
	157
[23]	158	/* this enum define the VFS inode types values */
	159
[10]	160	typedef enum
	161	{
[188]	162	INODE_TYPE_FILE = 0x001, /! file /
	163	INODE_TYPE_DIR = 0x002, /! directory /
	164	INODE_TYPE_FIFO = 0x004, /! POSIX named pipe /
	165	INODE_TYPE_PIPE = 0x008, /! POSIX anonymous pipe /
	166	INODE_TYPE_SOCK = 0x010, /! POSIX socket /
	167	INODE_TYPE_DEV = 0x020, /! device channel /
	168	INODE_TYPE_SYML = 0x080, /! symbolic link /
[10]	169	}
	170	vfs_inode_type_t;
	171
[23]	172	/* this enum define the VFS inode attributes values */
	173
[1]	174	typedef enum
	175	{
[23]	176	INODE_ATTR_DIRTY = 0x01, /* modified versus the value on device */
	177	INODE_ATTR_INLOAD = 0x04, /* loading from device in progress */
	178	INODE_ATTR_NEW = 0x08, /* not saved on device yet */
[1]	179	}
[10]	180	vfs_inode_attr_t;
[1]	181
	182	typedef struct vfs_inode_s
	183	{
[188]	184	struct vfs_ctx_s * ctx; /! local pointer on FS context /
	185	uint32_t gc; /! generation counter /
	186	uint32_t inum; /! inode identifier (unique in file system) /
	187	uint32_t attr; /! inode attributes (see above) /
	188	vfs_inode_type_t type; /! inode type (see above) /
	189	uint32_t size; /! number of bytes /
	190	uint32_t links; /! number of alias dentry /
	191	uid_t uid; /! user owner identifier /
	192	gid_t gid; /! group owner identifier /
	193	uint32_t rights; /! access rights /
	194	uint32_t refcount; /! reference counter (all pointers) /
	195	xptr_t parent_xp; /! extended pointer on parent dentry /
	196	xhtab_t children; /! embedded xhtab of children dentries /
	197	remote_rwlock_t data_lock; /! protect read/write to data and to size /
	198	remote_spinlock_t main_lock; /! protect inode tree traversal and modifs /
	199	list_entry_t list; /! member of set of inodes in same cluster /
	200	xlist_entry_t wait_root; /! root of threads waiting on this inode /
	201	struct mapper_s * mapper; /! associated file cache /
	202	void * extend; /! fs_type_specific inode extension /
[1]	203	}
	204	vfs_inode_t;
	205
	206	/******************************************************************************************
	207	* This structure defines a directory entry.
	208	* A dentry contains the name of a remote file/dir, an extended pointer on the
	209	* inode representing this file/dir, and a local pointer on the inode representing
	210	* the parent directory.
	211	*****************************************************************************************/
	212
	213	typedef struct vfs_dentry_s
	214	{
[188]	215	struct vfs_ctx_s * ctx; /! local pointer on FS context /
	216	char name[CONFIG_VFS_MAX_NAME_LENGTH];
	217	uint32_t length; /! name length (bytes) /
	218	uint32_t refcount; /! reference counter (all pointers) /
	219	struct vfs_inode_s * parent; /! local pointer on parent inode /
	220	xptr_t child_xp; /! extended pointer on child inode /
	221	xlist_entry_t list; /! member of list of dentries with same key /
	222	void * extend; /! FS specific extension /
[1]	223	}
	224	vfs_dentry_t;
	225
	226	/******************************************************************************************
[23]	227	* This file structure describes an open file/directory for a given process.
[1]	228	* It is not replicated, and is dynamically allocated in the cluster that contains
	229	* the inode, when a thread makes an open() or opendir() system call.
[23]	230	* It cannot exist a file structure without an inode structure.
[188]	231	* Aa the fd_array (containing extended pointers on the open file descriptors)* is replicated in all process descriptors, we need a references counter.
[23]	232	* is replicated in all process descriptors, we need a references counter.
[1]	233	*****************************************************************************************/
	234
	235	typedef enum
	236	{
[23]	237	FD_ATTR_READ_ENABLE = 0x01, /! read access possible /
	238	FD_ATTR_WRITE_ENABLE = 0x02, /! write access possible /
	239	FD_ATTR_APPEND = 0x04, /! append on each write /
	240	FD_ATTR_CLOSE_EXEC = 0x08, /! close file on exec /
	241	FD_ATTR_SYNC = 0x10, /! synchronise FS on each write /
	242	FD_ATTR_IS_DIR = 0x20, /! this is a directory /
[1]	243	}
[23]	244	vfs_file_attr_t;
[1]	245
	246	typedef struct vfs_file_s
	247	{
[23]	248	struct vfs_ctx_s * ctx; /! local pointer on FS context. /
[1]	249	uint32_t gc; /! generation counter /
[23]	250	vfs_file_attr_t attr; /! file attributes bit vector (see above) /
	251	vfs_inode_type_t type; /! same type as inode /
[1]	252	uint32_t offset; /! seek position in file /
[23]	253	uint32_t refcount; /! all pointers on this file descriptor /
	254	remote_rwlock_t lock; /! protect offset modifications /
[1]	255	struct mapper_s * mapper; /! associated file cache /
	256	struct vfs_inode_s * inode; /! local pointer on associated inode /
[23]	257	void * extend; /! FS specific extension /
[1]	258	}
	259	vfs_file_t;
	260
	261	/******************************************************************************************
[23]	262	* This structure define the informations associated to a file descriptor,
	263	* returned to user space by the stat() system call.
[1]	264	*****************************************************************************************/
	265
	266	typedef struct vfs_stat_s
	267	{
	268	uint32_t dev; /! ID of device containing file /
	269	uint32_t ino; /! inode number /
	270	uint32_t mode; /! protection /
	271	uint32_t nlink; /! number of hard links /
	272	uint32_t uid; /! user ID of owner /
	273	uint32_t gid; /! group ID of owner /
	274	uint32_t rdev; /! device ID (if special file) /
	275	uint64_t size; /! total size, in bytes /
	276	uint32_t blksize; /! blocksize for file system I/O /
	277	uint32_t blocks; /! number of 512B blocks allocated /
	278	uint64_t atime; /! time of last access /
	279	uint64_t mtime; /! time of last modification /
	280	uint64_t ctime; /! time of last status change /
	281	}
	282	vfs_stat_t;
	283
[23]	284	/*********************************************************************************************
	285	* This structure defines the information associated to a directory entry,
	286	* returned to user space by the readdir() system call.
	287	********************************************************************************************/
[1]	288
[23]	289	typedef struct vfs_dirent_s
[1]	290	{
[23]	291	uint32_t inum; /! inode identifier /
	292	uint32_t type; /! inode type /
	293	char name[CONFIG_VFS_MAX_NAME_LENGTH]; /! dentry name /
[1]	294	}
[23]	295	vfs_dirent_t;
[1]	296
	297
	298
	299	/*****************************************************************************************/
	300	/****************** VFS global functions *********************************************/
	301	/*****************************************************************************************/
	302
	303
	304	/******************************************************************************************
[23]	305	* This function mount a given file system type for a given process TODO.
[1]	306	*****************************************************************************************/
	307	error_t vfs_mount_fs_root( struct device_s * device,
	308	uint32_t fs_type,
	309	struct process_s * process );
	310
	311
	312	/*****************************************************************************************/
[188]	313	/***************** VFS Context related functions **************************************/
[1]	314	/*****************************************************************************************/
	315
	316	/******************************************************************************************
[188]	317	* This function initialise a (statically allocated) VFS context in local cluster.
	318	******************************************************************************************
	319	* @ fs_type : file system type.
	320	* @ attr : global attributes (for all files in FS.
	321	* @ total_clusters : total number of clusters on device.
	322	* @ cluster_size : cluster size on device (bytes).
	323	* @ vfs_root_xp : extended pointer on VFS root inode.
	324	* @ extend : fs_type_specific extension.
	325	*****************************************************************************************/
	326	void vfs_ctx_init( vfs_fs_type_t type,
	327	uint32_t attr,
	328	uint32_t total_clusters,
	329	uint32_t cluster_size,
	330	xptr_t vfs_root_xp,
	331	void * extend );
	332
	333	/******************************************************************************************
[1]	334	* This function allocates an inode identifier from the local cluster inum allocator.
	335	* The inum respects a fixed format:
	336	* - the 16 MSB bits contain the cluster identifier : cxy
	337	* - the 16 LSB bits contains the local inode identifier : lid
	338	******************************************************************************************
	339	* @ ctx : local pointer on file system context.
	340	* @ inum : [ou] buffer for allocated inode identifier.
	341	* @ return 0 if success / return non-zero if error.
	342	*****************************************************************************************/
	343	error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx,
	344	uint32_t * inum );
	345
	346	/******************************************************************************************
	347	* This function release an inode identifier.
	348	******************************************************************************************
	349	* @ ctx : local pointer on file system context.
	350	* @ inum : released inode identifier.
	351	*****************************************************************************************/
	352	void vfs_ctx_inum_release( vfs_ctx_t * ctx,
	353	uint32_t inum );
	354
	355
	356
	357
	358	/*****************************************************************************************/
	359	/******************* Inode related functions *****************************************/
	360	/*****************************************************************************************/
	361
	362	/******************************************************************************************
	363	* This function allocates memory from local cluster for an inode descriptor and the
	364	* associated mapper. It initialise these descriptors from arguments values.
	365	* The parent dentry must have been previously created.
	366	* If the client thread is not running in the cluster containing this inode,
	367	* it must use the rpc_vfs_inode_create_client() function.
	368	******************************************************************************************
	369	* @ dentry_xp : extended pointer on associated dentry (in parent inode cluster).
[23]	370	* @ fs_type : file system type.
	371	* @ inode_type : inode type.
[188]	372	* @ extend : local pointer on vs_type_specific extension.
[1]	373	* @ attr : inode attributes.
[23]	374	* @ rights : inode access rights.
[1]	375	* @ uid : user owner ID.
	376	* @ gid : group owner ID.
	377	* @ inode_xp : [out] buffer for extended pointer on created inode.
	378	* # return 0 if success / return ENOMEM or EINVAL if error.
	379	*****************************************************************************************/
[23]	380	error_t vfs_inode_create( xptr_t dentry_xp,
	381	vfs_fs_type_t fs_type,
	382	vfs_inode_type_t inode_type,
[188]	383	void * extend,
[23]	384	uint32_t attr,
	385	uint32_t rights,
	386	uid_t uid,
	387	gid_t gid,
	388	xptr_t * inode_xp );
[1]	389
	390	/******************************************************************************************
	391	* This function releases memory allocated to an inode descriptor.
	392	* It must be executed by a thread running in the cluster containing the inode,
	393	* and the inode refcount must be zero.
	394	* If the client thread is not running in the owner cluster, it must use the
	395	* rpc_vfs_inode_destroy_client() function.
	396	******************************************************************************************
	397	* @ inode : local pointer on inode descriptor.
	398	*****************************************************************************************/
	399	void vfs_inode_destroy( vfs_inode_t * inode );
	400
	401	/******************************************************************************************
[23]	402	* This function atomically increment/decrement the inode refcount.
[1]	403	* It can be called by any thread running in any cluster.
	404	*****************************************************************************************/
	405	void vfs_inode_remote_up( xptr_t inode_xp );
	406	void vfs_inode_remote_down( xptr_t inode_xp );
	407
	408	/******************************************************************************************
	409	* This function returns the <size> of a file/dir from a remote inode,
	410	* taking the remote_rwlock protecting <size> in READ_MODE.
	411	*****************************************************************************************
	412	* @ inode_xp : extended pointer on the remote inode.
	413	* @ return the current size.
	414	*****************************************************************************************/
	415	uint32_t vfs_inode_get_size( xptr_t inode_xp );
	416
	417	/******************************************************************************************
	418	* This function set the <size> of a file/dir to a remote inode,
	419	* taking the remote_rwlock protecting <size> in WRITE_MODE.
	420	*****************************************************************************************
	421	* @ inode_xp : extended pointer on the remote inode.
	422	* @ size : value to be written.
	423	*****************************************************************************************/
	424	void vfs_inode_set_size( xptr_t inode_xp,
	425	uint32_t size );
	426
	427	/******************************************************************************************
	428	* This function takes the main lock of a remote inode.
	429	* This lock protect all inode fiels, including the children dentries.
	430	*****************************************************************************************
	431	* @ inode_xp : extended pointer on the remote inode.
	432	*****************************************************************************************/
[101]	433	void vfs_inode_lock( xptr_t inode_xp );
[1]	434
	435	/******************************************************************************************
	436	* This function releases the main lock of a remote inode.
	437	* This lock protect all inode fiels, including the children dentries.
	438	*****************************************************************************************
	439	* @ inode_xp : extended pointer on the remote inode.
	440	*****************************************************************************************/
[101]	441	void vfs_inode_unlock( xptr_t inode_xp );
[1]	442
	443	/******************************************************************************************
[101]	444	* This debug function returns the current owner of the inode main lock.
	445	*****************************************************************************************
	446	* @ inode_xp : extended pointer on the remote inode.
	447	* @ return extended pointer on owner thread / return XPTR_NULL if lock not taken.
[1]	448	*****************************************************************************************/
[101]	449	xptr_t vfs_inode_owner( xptr_t inode_xp );
[1]	450
	451	/******************************************************************************************
	452	* This function TODO
	453	*****************************************************************************************/
	454	error_t vfs_inode_trunc( vfs_inode_t * inode );
	455
	456	/******************************************************************************************
	457	* This function TODO
	458	*****************************************************************************************/
	459	error_t vfs_inode_link( vfs_inode_t * inode,
	460	uint32_t igc );
	461
	462	/******************************************************************************************
	463	* This function TODO
	464	*****************************************************************************************/
	465	error_t vfs_inode_unlink( vfs_inode_t * inode );
	466
	467	/******************************************************************************************
	468	* This function TODO
	469	*****************************************************************************************/
	470	error_t vfs_inode_stat( vfs_inode_t * inode,
	471	uint32_t inum );
	472
	473	/******************************************************************************************
	474	* This function TODO
	475	*****************************************************************************************/
	476	error_t vfs_icache_del( vfs_inode_t * inode );
	477
	478
	479	/******************************************************************************************
	480	* This function TODO Pourquoi 2 arguments ?
	481	*****************************************************************************************/
	482	error_t vfs_stat_inode( vfs_inode_t * inode,
	483	uint32_t inum );
	484
	485
	486	/*****************************************************************************************/
	487	/*************** Dentry related functions ********************************************/
	488	/*****************************************************************************************/
	489
	490	/******************************************************************************************
	491	* This function allocates memory from local cluster for a dentry descriptor,
	492	* initialises it from arguments values, and returns the extended pointer on dentry.
	493	* The inode field is not initialized, because the inode does not exist yet.
	494	* If the client thread is not running in the target cluster for this inode,
	495	* it must use the rpc_dentry_create_client() function.
	496	******************************************************************************************
[23]	497	* @ fs_type : file system type.
[1]	498	* @ name : directory entry file/dir name.
	499	* @ parent : local pointer on parent inode.
[23]	500	* @ dentry_xp : [out] buffer for extended pointer on created dentry.
[1]	501	* @ return 0 if success / return ENOMEM or EINVAL if error.
	502	*****************************************************************************************/
[23]	503	error_t vfs_dentry_create( vfs_fs_type_t fs_type,
	504	char * name,
	505	vfs_inode_t * parent,
	506	xptr_t * dentry_xp );
[1]	507
	508	/******************************************************************************************
	509	* This function releases memory allocated to a dentry descriptor.
	510	* It must be executed by a thread running in the cluster containing the dentry,
	511	* and the dentry refcount must be zero.
	512	* If the client thread is not running in the owner cluster, it must use the
	513	* rpc_dentry_destroy_client() function.
	514	******************************************************************************************
	515	* @ dentry : local pointer on dentry descriptor.
	516	*****************************************************************************************/
	517	void vfs_dentry_destroy( vfs_dentry_t * dentry );
	518
	519	/******************************************************************************************
[23]	520	* These functions atomically increment/decrement the dentry refcount.
[1]	521	* It can be called by any thread running in any cluster.
	522	*****************************************************************************************/
	523	void vfs_dentry_remote_up( xptr_t dentry_xp );
[23]	524	void vfs_dentry_remote_down( xptr_t dentry_xp );
[1]	525
[23]	526
	527	/*****************************************************************************************/
	528	/********************** File descriptor related functions ****************************/
	529	/*****************************************************************************************/
	530
[1]	531	/******************************************************************************************
[23]	532	* This function allocates memory and initializes a new local file descriptor.
	533	* It must be executed in the cluster containing the inode.
	534	* If the client thread is not running in the owner cluster, it must use the
	535	* rpc_vfs_file_create_client() function.
	536	******************************************************************************************
	537	* @ inode : local pointer on associated inode.
	538	* @ attr : file descriptor attributes.
	539	* @ file_xp : [out] buffer for extended pointer on created file descriptor.
	540	* @ return 0 if success / return ENOMEM if error.
[1]	541	*****************************************************************************************/
[23]	542	error_t vfs_file_create( vfs_inode_t * inode,
	543	uint32_t attr,
	544	xptr_t * file_xp );
[1]	545
[23]	546	/******************************************************************************************
	547	* This function releases memory allocated to a local file descriptor.
	548	* It must be executed by a thread running in the cluster containing the inode,
	549	* and the file refcount must be zero.
	550	* If the client thread is not running in the owner cluster, it must use the
	551	* rpc_vfs_file_destroy_client() function.
	552	******************************************************************************************
	553	* @ file : local pointer on file descriptor.
	554	*****************************************************************************************/
	555	void vfs_file_destroy( vfs_file_t * file );
[1]	556
[23]	557	/******************************************************************************************
	558	* These functions increment (resp. decrement) the count field in a remote file
	559	* descriptor, using a remote_atomic access.
	560	*****************************************************************************************/
	561	void vfs_file_count_up ( xptr_t file_xp );
	562	void vfs_file_count_down( xptr_t file_xp );
	563
	564
	565
[1]	566	/*****************************************************************************************/
[23]	567	/***************** Inode-Tree related functions **************************************/
[1]	568	/*****************************************************************************************/
	569
	570	/******************************************************************************************
[188]	571	* This function randomly selects a cluster for a new inode.
	572	******************************************************************************************
	573	* @ returns the selected cluster identifier.
	574	*****************************************************************************************/
	575	cxy_t vfs_cluster_random_select();
	576
	577	/******************************************************************************************
[1]	578	* This function returns in a kernel buffer allocated by the caller function,
	579	* the pathname of a file/dir identified by an extended pointer on the inode.
	580	* It traverse the Inode Tree from the target node to the root.
	581	* It can be called by any thread running in any cluster.
	582	******************************************************************************************
	583	* @ inode_xp : pointer on inode descriptor.
	584	* @ buffer : kernel buffer for pathname (must be allocated by caller).
	585	* @ size : max number of characters in buffer.
	586	* @ return 0 if success / return EINVAL if buffer too small.
	587	*****************************************************************************************/
	588	error_t vfs_get_path( xptr_t inode_xp,
	589	char * buffer,
	590	uint32_t max_size );
	591
	592	/******************************************************************************************
	593	* This function takes a pathname (absolute or relative to cwd) and returns an extended
[23]	594	* pointer on the associated inode.
	595	* - If a given name in the path is not found in the inode tree, it try to load the missing
	596	* dentry/inode couple, from informations found in the parent directory.
	597	* - If this directory entry does not exist on device, it returns an error.
	598	* - If the the file identified by the pathname does not exist on device but the
	599	* flag CREATE is set, the inode is created.
	600	* - If the the file identified by the pathname exist on device but both flags EXCL
	601	* and CREATE are set, an error is returned.
[1]	602	******************************************************************************************
[23]	603	* @ cwd_xp : extended pointer on current directory (for relative path).
	604	* @ pathname : path in kernel space (can be relative or absolute).
	605	* @ lookup_mode : flags defining the working mode (defined above in this file).
	606	* @ inode_xp : [out] buffer for extended pointer on inode.
	607	* @ return 0 if success / ENOENT if inode not found , EACCES if permissopn denied,
	608	* EAGAIN if a new complete lookup must be made
[1]	609	*****************************************************************************************/
[23]	610	error_t vfs_lookup( xptr_t cwd_xp,
	611	char * pathname,
	612	uint32_t lookup_mode,
	613	xptr_t * inode_xp );
[1]	614
	615	/******************************************************************************************
	616	* This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
	617	* It can be executed by any thread running in any cluster, as this function
	618	* uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
	619	* - The dentry is created in the cluster containing the existing <parent_xp> inode.
[188]	620	* - the inode and its associated mapper are created in cluster identified by <child_cxy>.
[23]	621	* - The new dentry name is defined by the <name> argument.
	622	* - The new inode and the parent inode can have different FS types.
[1]	623	******************************************************************************************
[188]	624	* @ child_cxy : target cluster for child inode.
[23]	625	* @ inode_type : new inode type
	626	* @ fs_type : new inode FS type.
[1]	627	* @ parent_xp : extended pointer on parent inode.
	628	* @ name : new directory entry name.
[188]	629	* @ extend : fs_type_specific inode extension.
[1]	630	* @ child_xp : [out] buffer for extended pointer on child inode.
	631	* @ return 0 if success / ENOENT if entry not found in parent directory
	632	*****************************************************************************************/
[188]	633	error_t vfs_add_child_in_parent( cxy_t child_cxy,
	634	vfs_inode_type_t inode_type,
[23]	635	vfs_fs_type_t fs_type,
	636	xptr_t parent_xp,
	637	char * name,
[188]	638	void * extend,
[23]	639	xptr_t * child_xp );
[1]	640
	641	/******************************************************************************************
[23]	642	* This function removes a couple dentry/inode from the Inode-Tree, and remove it from
	643	* the external device.
	644	* TODO
[1]	645	******************************************************************************************
	646	* @ child_xp : extended pointer on removed inode.
	647	*****************************************************************************************/
	648	error_t vfs_remove_child_from_parent( xptr_t child_xp );
	649
[188]	650	/******************************************************************************************
	651	* This recursive function diplays a complete inode/dentry sub-tree.
	652	* Any inode can be selected as the sub-tree root.
	653	* TODO this function is not ptotected against a concurrent node removal...
	654	******************************************************************************************
	655	* @ inode_xp : extended pointer on sub-tree root inode.
	656	*****************************************************************************************/
	657	void vfs_display( xptr_t inode_xp );
[23]	658
	659
	660
	661
	662
[1]	663	/*****************************************************************************************/
[23]	664	/**************** File access API ****************************************************/
[1]	665	/*****************************************************************************************/
	666
	667	/******************************************************************************************
	668	* This function allocates a vfs_file_t structure in the cluster containing the inode
[23]	669	* associated to the file identified by <cwd_xp> & <path>.
	670	* It initializes it, register it in the reference process fd_array, and returns both
	671	* the extended pointer on the remote file descriptor, and the index in the fd_array.
[1]	672	* The pathname can be relative to current directory or absolute.
[23]	673	* If the inode does not exist in the inode cache, it try to find the file on the mounted
[1]	674	* device, and creates an inode on a pseudo randomly selected cluster if found.
	675	* It the requested file does not exist on device, it creates a new inode if the
	676	* O_CREAT flag is set and return an error otherwise.
	677	******************************************************************************************
[23]	678	* @ cwd_xp : extended pointer on current working directory file descriptor.
	679	* @ path : file pathname (absolute or relative to current directory).
	680	* @ flags : defined above
	681	* @ mode : access rights (as defined by chmod)
	682	* @ file_xp : [out] buffer for extended pointer on created remote file descriptor.
	683	* @ file_id : [out] buffer for created file descriptor index in reference fd_array.
[1]	684	* @ return 0 if success / return non-zero if error.
	685	*****************************************************************************************/
	686	error_t vfs_open( xptr_t cwd_xp,
	687	char * path,
	688	uint32_t flags,
[23]	689	uint32_t mode,
	690	xptr_t * file_xp,
	691	uint32_t * file_id );
[1]	692
	693	/******************************************************************************************
[23]	694	* This function moves <size> bytes between the file identified by the open file descriptor
	695	* <file_xp> and a local kernel <buffer> , taken into account the offset in <file_xp>.
	696	* The transfer direction is defined by the <to_buffer> argument.
	697	******************************************************************************************
	698	* @ to_buffer : mapper -> buffer if true / buffer->mapper if false.
	699	* @ file_xp : extended pointer on the remote file descriptor.
	700	* @ buffer : local pointer on local kernel buffer.
[1]	701	* @ size : requested number of bytes from offset.
	702	* @ returns number of bytes actually transfered / -1 if error.
	703	*****************************************************************************************/
[23]	704	error_t vfs_move( bool_t to_buffer,
	705	xptr_t file_xp,
	706	void * buffer,
	707	uint32_t size );
[1]	708
	709	/******************************************************************************************
	710	* This function set a new value in the offset of the open file descriptor <file_xp>.
	711	* This value depends on the <whence> argument:
	712	* - if VFS_SEEK_SET, new value is <offset>
	713	* - if VFS_SEEK_CUR, new value is current_offset + <offset>
	714	* - if VFS_SEEK_END, new value is file_size + <offset>
	715	******************************************************************************************
	716	* @ file_xp : extended pointer on the remote open file descriptor.
	717	* @ offset : local pointer on source kernel buffer.
	718	* @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
	719	* @ new_offset : [out] buffer for new offset value.
	720	* @ returns 0 if success / -1 if error.
	721	*****************************************************************************************/
	722	error_t vfs_lseek( xptr_t file_xp,
	723	uint32_t offset,
	724	uint32_t whence,
	725	uint32_t * new_offset );
	726
	727	/******************************************************************************************
[23]	728	* This function close an open file descriptor:
	729	* 1) All entries in fd_array copies are directly cancelled by the calling thread,
	730	* using remote accesses.
	731	* 2) The memory allocated to file descriptor in cluster containing the inode is released.
	732	* It requires a RPC if cluster containing the file descriptor is remote.
[1]	733	******************************************************************************************
	734	* @ file_xp : extended pointer on the file descriptor.
[23]	735	* @ file_id : file descriptor index in fd_array.
	736	* @ returns 0 if success / -1 if error.
[1]	737	*****************************************************************************************/
[23]	738	error_t vfs_close( xptr_t file_xp,
	739	uint32_t file_id );
[1]	740
	741	/******************************************************************************************
[23]	742	* This function remove from the file system a directory entry identified by the
	743	* <cwd_xp> & <path> arguments.
[1]	744	******************************************************************************************
[23]	745	* @ cwd_xp : extended pointer on the current working directory file descriptor.
[1]	746	* @ path : pathname (absolute or relative to current directory).
[23]	747	* @ returns 0 if success / -1 if error.
[1]	748	*****************************************************************************************/
	749	error_t vfs_unlink( xptr_t cwd_xp,
	750	char * path );
	751
	752	/******************************************************************************************
[23]	753	* This function returns, in the structure pointed by the <k_stat> kernel pointer,
	754	* various informations on the file descriptor identified by the <file_xp> argument.
	755	* TODO not implemented yet...
	756	******************************************************************************************
	757	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	758	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	759	* @ returns 0 if success / -1 if error.
[1]	760	*****************************************************************************************/
	761	error_t vfs_stat( xptr_t file_xp,
[23]	762	vfs_stat_t * k_stat );
[1]	763
	764	/******************************************************************************************
[23]	765	* This function returns, in the structure pointed by the <k_dirent> kernel pointer,
	766	* various infos on the directory entry currently pointed by the <file_xp> file descriptor.
	767	* TODO not implemented yet...
	768	******************************************************************************************
	769	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	770	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	771	* @ returns 0 if success / -1 if error.
[1]	772	*****************************************************************************************/
[23]	773	error_t vfs_readdir( xptr_t file_xp,
	774	vfs_dirent_t * k_dirent );
[1]	775
	776	/******************************************************************************************
[23]	777	* This function creates a new inode and associated dentry for the directory defined
	778	* by the <cwd_xp> & <path> arguments.
	779	* TODO not implemented yet...
	780	******************************************************************************************
	781	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	782	* @ path : pathname (absolute or relative to current directory).
	783	* @ mode : access rights (as defined by chmod)
	784	* @ returns 0 if success / -1 if error.
[1]	785	*****************************************************************************************/
[23]	786	error_t vfs_mkdir( xptr_t cwd_xp,
	787	char * path,
	788	uint32_t mode );
[1]	789
	790	/******************************************************************************************
[23]	791	* This function remove a directory identified by the <cwd_xp / path> arguments
	792	* from the file system.
	793	* TODO not implemented yet...
	794	******************************************************************************************
	795	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	796	* @ path : pathname (absolute or relative to current directory).
	797	* @ returns 0 if success / -1 if error.
[1]	798	*****************************************************************************************/
[23]	799	error_t vfs_rmdir( xptr_t cwd_xp,
	800	char * path );
[1]	801
	802	/******************************************************************************************
[23]	803	* This function makes the directory identified by <cwd_xp / path> arguments to become
	804	* the working directory for the calling process.
	805	******************************************************************************************
	806	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	807	* @ path : file pathname (absolute or relative to current directory).
	808	* return 0 if success / -1 if error.
[1]	809	*****************************************************************************************/
[23]	810	error_t vfs_chdir( xptr_t cwd_xp,
	811	char * path );
[1]	812
	813	/******************************************************************************************
[23]	814	* This function change the access rigths for the file identified by the <cwd_xp / path>
	815	* arguments. The new access rights are defined by the <mode> argument value.
	816	******************************************************************************************
	817	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	818	* @ path : file pathname (absolute or relative to current directory).
	819	* @ mode : access rights new value.
	820	* return 0 if success / -1 if error.
[1]	821	*****************************************************************************************/
[23]	822	error_t vfs_chmod( xptr_t cwd_xp,
	823	char * path,
	824	uint32_t mode );
[1]	825
	826	/******************************************************************************************
[23]	827	* This function creates a named FIFO file.
	828	* TODO not implemented yet
	829	******************************************************************************************
	830	* @ path : FIFO pathname (absolute or relative to current directory).
	831	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	832	* @ mode : access rights new value.
[1]	833	*****************************************************************************************/
[23]	834	error_t vfs_mkfifo( xptr_t cwd_xp,
	835	char * path,
	836	uint32_t mode );
[1]	837
	838
	839	/*****************************************************************************************/
[23]	840	/**************** Mapper access API **************************************************/
[1]	841	/*****************************************************************************************/
	842
[23]	843	/******************************************************************************************
	844	* This function makes an I/O operation to move one page from VFS to a given mapper,
	845	* in case of MISS on the mapper cache.
	846	* Depending on the file system type, it calls the proper, FS specific function.
	847	* It must be executed by a thread running in the cluster containing the mapper.
	848	* The mapper pointer is obtained from the page descriptor.
	849	* It takes the mapper lock before launching the IO operation.
	850	******************************************************************************************
	851	* @ page : local pointer on the page descriptor.
	852	* @ returns 0 if success / return EINVAL if it cannot access the external device.
[1]	853	*****************************************************************************************/
[23]	854	error_t vfs_move_page_to_mapper( struct page_s * page );
[1]	855
[23]	856	/******************************************************************************************
	857	* This function makes an I/0 operation to move one page from a given mapper to VFS,
	858	* when a dirty page in the mapper cache must be updated in the File System.
	859	* Depending on the file system type, it calls the proper, FS specific function.
	860	* It must be executed by a thread running in the cluster containing the mapper.
	861	* The mapper pointer is obtained from the page descriptor.
	862	* It takes the mapper lock before launching the IO operation.
	863	* It does nothing if the page is not dirty. If the page is dirty, it clear the page
	864	* dirty bit, and remove the page from the PPM dirty list.
	865	******************************************************************************************
	866	* @ page : local pointer on the page descriptor.
	867	* @ returns 0 if success / return EINVAL if it cannot access the external device.
[1]	868	*****************************************************************************************/
[23]	869	error_t vfs_move_page_from_mapper( struct page_s * page );
[1]	870
	871
	872
	873
[23]	874
	875
	876	///////////////////////////////////////////////////////////////////////////////////////////
	877	// These typedef define the FS specific operations that must be implemented by any
	878	// specific file system to be supported by the ALMOS_MKH VFS.
	879	// These typedef are not actually used, and are only defined for documentation
	880	///////////////////////////////////////////////////////////////////////////////////////////
	881
	882	typedef error_t (fs_init_t) ( xptr_t vfs_root_xp );
	883
	884	typedef error_t (fs_inode_extend_t) ( struct vfs_inode_s * inode,
	885	void * extend );
	886
	887	typedef void (fs_inode_release_t) ( struct vfs_inode_s * inode );
	888
	889	typedef error_t (fs_write_page_t) ( struct page_s * page );
	890
	891	typedef error_t (fs_read_page_t) ( struct page_s * page );
	892
	893
	894
	895
	896
	897
	898
	899
	900	/* deprecated [AG]
	901
	902	typedef error_t (lookup_inode_t) ( vfs_inode_t * parent ,
	903	vfs_dentry_t * dentry );
	904
	905	typedef error_t (write_inode_t) ( vfs_inode_t * inode );
	906
	907	typedef error_t (release_inode_t) ( vfs_inode_t * inode );
	908
	909	typedef error_t (unlink_inode_t) ( vfs_inode_t * parent,
	910	vfs_dentry_t * dentry,
	911	uint32_t flags );
	912
	913	typedef error_t (stat_inode_t) ( vfs_inode_t * inode );
	914
	915	typedef error_t (trunc_inode_t) ( vfs_inode_t * inode );
	916
	917	typedef error_t (delete_inode_t) ( vfs_inode_t * inode );
	918
	919	typedef struct vfs_inode_op_s
	920	{
	921	init_inode_t * init;
	922	create_inode_t * create;
	923	lookup_inode_t * lookup;
	924	write_inode_t * write;
	925	release_inode_t * release;
	926	unlink_inode_t * unlink;
	927	delete_inode_t * delete;
	928	stat_inode_t * stat;
	929	trunc_inode_t * trunc; // change the size of a file
	930	}
	931	vfs_inode_op_t;
	932
	933	******************************************************************************************
	934	* These typedef define the set of FS specific operations on a VFS DENTRY descriptor.
	935	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	936	* This code is not actually used, and is only defined for documentation
	937	******************************************************************************************
	938
	939
	940	typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
	941
	942	typedef struct vfs_dentry_op_s
	943	{
	944	vfs_compare_dentry_t * compare;
	945	}
	946	vfs_dentry_op_t;
	947
	948
	949	******************************************************************************************
	950	* These typedef define the set of FS specific operations on FILE descriptors
	951	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	952	* This code is not actually used, and is only defined for documentation
	953	******************************************************************************************
	954
	955
	956	typedef error_t (open_file_t ) ( vfs_file_t * file,
	957	void * extend );
	958
	959	typedef error_t (read_file_t ) ( vfs_file_t * file,
	960	char * buffer,
	961	uint32_t count );
	962
	963	typedef error_t (write_file_t ) ( vfs_file_t * file,
	964	char * buffer,
	965	uint32_t count );
	966
	967	typedef error_t (lseek_file_t ) ( vfs_file_t * file );
	968
	969	typedef error_t (close_file_t ) ( vfs_file_t * file );
	970
	971	typedef error_t (release_file_t) ( vfs_file_t * file );
	972
	973	typedef error_t (read_dir_t ) ( vfs_file_t * file );
	974
	975	typedef error_t (mmap_file_t ) ( vfs_file_t * file ,
	976	struct vseg_s * vseg );
	977
	978	typedef error_t (munmap_file_t ) ( vfs_file_t * file,
	979	struct vseg_s * vseg );
	980
	981	typedef struct vfs_file_op_s
	982	{
	983	open_file_t * open;
	984	read_file_t * read;
	985	write_file_t * write;
	986	lseek_file_t * lseek;
	987	read_dir_t * readdir;
	988	close_file_t * close;
	989	release_file_t * release;
	990	mmap_file_t * mmap;
	991	munmap_file_t * munmap;
	992	}
	993	vfs_file_op_t;
	994
	995	*/
	996
[1]	997	#endif /* _VFS_H_ */

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