Context Navigation

source: trunk/kernel/vfs/vfs.h @ 242

Last change on this file since 242 was 239, checked in by alain, 7 years ago
bloup
File size: 52.4 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
[238]	401	/******************************************************************************************
	402	* This function scan an existing parent inode directory, identified by the <parent>
	403	* argument to find a directory entry identified by the <name> argument, and update
	404	* the remote child inode, identified by the <child_xp> argument.
	405	* Depending on the file system type, it calls the relevant, FS specific function,
	406	* to scan the directory, and set the "type", "size", and "extend" fields.
	407	* It must be called by a thread running in the cluster containing the parent inode.
	408	******************************************************************************************
	409	* @ parent : local pointer on parent inode (directory).
	410	* @ name : child name.
	411	* @ child_xp : extended pointer on remote child inode (file or directory)
	412	* @ return 0 if success / return ENOENT if not found.
	413	*****************************************************************************************/
	414	error_t vfs_inode_load( vfs_inode_t * parent,
	415	char * name,
	416	xptr_t child_xp );
	417
[1]	418	/******************************************************************************************
[23]	419	* This function atomically increment/decrement the inode refcount.
[1]	420	* It can be called by any thread running in any cluster.
	421	*****************************************************************************************/
	422	void vfs_inode_remote_up( xptr_t inode_xp );
	423	void vfs_inode_remote_down( xptr_t inode_xp );
	424
	425	/******************************************************************************************
	426	* This function returns the <size> of a file/dir from a remote inode,
	427	* taking the remote_rwlock protecting <size> in READ_MODE.
	428	*****************************************************************************************
	429	* @ inode_xp : extended pointer on the remote inode.
	430	* @ return the current size.
	431	*****************************************************************************************/
	432	uint32_t vfs_inode_get_size( xptr_t inode_xp );
	433
	434	/******************************************************************************************
	435	* This function set the <size> of a file/dir to a remote inode,
	436	* taking the remote_rwlock protecting <size> in WRITE_MODE.
	437	*****************************************************************************************
	438	* @ inode_xp : extended pointer on the remote inode.
	439	* @ size : value to be written.
	440	*****************************************************************************************/
	441	void vfs_inode_set_size( xptr_t inode_xp,
	442	uint32_t size );
	443
	444	/******************************************************************************************
	445	* This function takes the main lock of a remote inode.
	446	* This lock protect all inode fiels, including the children dentries.
	447	*****************************************************************************************
	448	* @ inode_xp : extended pointer on the remote inode.
	449	*****************************************************************************************/
[101]	450	void vfs_inode_lock( xptr_t inode_xp );
[1]	451
	452	/******************************************************************************************
	453	* This function releases the main lock of a remote inode.
	454	* This lock protect all inode fiels, including the children dentries.
	455	*****************************************************************************************
	456	* @ inode_xp : extended pointer on the remote inode.
	457	*****************************************************************************************/
[101]	458	void vfs_inode_unlock( xptr_t inode_xp );
[1]	459
	460	/******************************************************************************************
[101]	461	* This debug function returns the current owner of the inode main lock.
	462	*****************************************************************************************
	463	* @ inode_xp : extended pointer on the remote inode.
	464	* @ return extended pointer on owner thread / return XPTR_NULL if lock not taken.
[1]	465	*****************************************************************************************/
[101]	466	xptr_t vfs_inode_owner( xptr_t inode_xp );
[1]	467
	468	/******************************************************************************************
[204]	469	* This debug function diplays the name of the inode identified by the <inode_xp>
	470	* argument, and all children names for a directory.
	471	*****************************************************************************************
	472	* @ inode_xp : extended pointer on the remote inode.
	473	*****************************************************************************************/
	474	void vfs_inode_display( xptr_t inode_xp );
	475
	476
	477
	478
	479
	480
	481	/******************************************************************************************
[1]	482	* This function TODO
	483	*****************************************************************************************/
	484	error_t vfs_inode_trunc( vfs_inode_t * inode );
	485
	486	/******************************************************************************************
	487	* This function TODO
	488	*****************************************************************************************/
	489	error_t vfs_inode_link( vfs_inode_t * inode,
	490	uint32_t igc );
	491
	492	/******************************************************************************************
	493	* This function TODO
	494	*****************************************************************************************/
	495	error_t vfs_inode_unlink( vfs_inode_t * inode );
	496
	497	/******************************************************************************************
	498	* This function TODO
	499	*****************************************************************************************/
	500	error_t vfs_inode_stat( vfs_inode_t * inode,
	501	uint32_t inum );
	502
	503	/******************************************************************************************
	504	* This function TODO
	505	*****************************************************************************************/
	506	error_t vfs_icache_del( vfs_inode_t * inode );
	507
	508
	509	/******************************************************************************************
	510	* This function TODO Pourquoi 2 arguments ?
	511	*****************************************************************************************/
	512	error_t vfs_stat_inode( vfs_inode_t * inode,
	513	uint32_t inum );
	514
	515
	516	/*****************************************************************************************/
	517	/*************** Dentry related functions ********************************************/
	518	/*****************************************************************************************/
	519
	520	/******************************************************************************************
	521	* This function allocates memory from local cluster for a dentry descriptor,
	522	* initialises it from arguments values, and returns the extended pointer on dentry.
	523	* The inode field is not initialized, because the inode does not exist yet.
	524	* If the client thread is not running in the target cluster for this inode,
	525	* it must use the rpc_dentry_create_client() function.
	526	******************************************************************************************
[23]	527	* @ fs_type : file system type.
[1]	528	* @ name : directory entry file/dir name.
	529	* @ parent : local pointer on parent inode.
[23]	530	* @ dentry_xp : [out] buffer for extended pointer on created dentry.
[1]	531	* @ return 0 if success / return ENOMEM or EINVAL if error.
	532	*****************************************************************************************/
[23]	533	error_t vfs_dentry_create( vfs_fs_type_t fs_type,
	534	char * name,
	535	vfs_inode_t * parent,
	536	xptr_t * dentry_xp );
[1]	537
	538	/******************************************************************************************
	539	* This function releases memory allocated to a dentry descriptor.
	540	* It must be executed by a thread running in the cluster containing the dentry,
	541	* and the dentry refcount must be zero.
	542	* If the client thread is not running in the owner cluster, it must use the
	543	* rpc_dentry_destroy_client() function.
	544	******************************************************************************************
	545	* @ dentry : local pointer on dentry descriptor.
	546	*****************************************************************************************/
	547	void vfs_dentry_destroy( vfs_dentry_t * dentry );
	548
	549	/******************************************************************************************
[23]	550	* These functions atomically increment/decrement the dentry refcount.
[1]	551	* It can be called by any thread running in any cluster.
	552	*****************************************************************************************/
	553	void vfs_dentry_remote_up( xptr_t dentry_xp );
[23]	554	void vfs_dentry_remote_down( xptr_t dentry_xp );
[1]	555
[23]	556
	557	/*****************************************************************************************/
	558	/********************** File descriptor related functions ****************************/
	559	/*****************************************************************************************/
	560
[1]	561	/******************************************************************************************
[23]	562	* This function allocates memory and initializes a new local file descriptor.
	563	* It must be executed in the cluster containing the inode.
	564	* If the client thread is not running in the owner cluster, it must use the
	565	* rpc_vfs_file_create_client() function.
	566	******************************************************************************************
	567	* @ inode : local pointer on associated inode.
	568	* @ attr : file descriptor attributes.
	569	* @ file_xp : [out] buffer for extended pointer on created file descriptor.
	570	* @ return 0 if success / return ENOMEM if error.
[1]	571	*****************************************************************************************/
[23]	572	error_t vfs_file_create( vfs_inode_t * inode,
	573	uint32_t attr,
	574	xptr_t * file_xp );
[1]	575
[23]	576	/******************************************************************************************
	577	* This function releases memory allocated to a local file descriptor.
	578	* It must be executed by a thread running in the cluster containing the inode,
	579	* and the file refcount must be zero.
	580	* If the client thread is not running in the owner cluster, it must use the
	581	* rpc_vfs_file_destroy_client() function.
	582	******************************************************************************************
	583	* @ file : local pointer on file descriptor.
	584	*****************************************************************************************/
	585	void vfs_file_destroy( vfs_file_t * file );
[1]	586
[23]	587	/******************************************************************************************
	588	* These functions increment (resp. decrement) the count field in a remote file
	589	* descriptor, using a remote_atomic access.
	590	*****************************************************************************************/
	591	void vfs_file_count_up ( xptr_t file_xp );
	592	void vfs_file_count_down( xptr_t file_xp );
	593
	594
	595
[1]	596	/*****************************************************************************************/
[23]	597	/***************** Inode-Tree related functions **************************************/
[1]	598	/*****************************************************************************************/
	599
	600	/******************************************************************************************
[188]	601	* This function randomly selects a cluster for a new inode.
	602	******************************************************************************************
	603	* @ returns the selected cluster identifier.
	604	*****************************************************************************************/
	605	cxy_t vfs_cluster_random_select();
	606
	607	/******************************************************************************************
[1]	608	* This function returns in a kernel buffer allocated by the caller function,
	609	* the pathname of a file/dir identified by an extended pointer on the inode.
	610	* It traverse the Inode Tree from the target node to the root.
	611	* It can be called by any thread running in any cluster.
	612	******************************************************************************************
	613	* @ inode_xp : pointer on inode descriptor.
	614	* @ buffer : kernel buffer for pathname (must be allocated by caller).
	615	* @ size : max number of characters in buffer.
	616	* @ return 0 if success / return EINVAL if buffer too small.
	617	*****************************************************************************************/
	618	error_t vfs_get_path( xptr_t inode_xp,
	619	char * buffer,
	620	uint32_t max_size );
	621
	622	/******************************************************************************************
	623	* This function takes a pathname (absolute or relative to cwd) and returns an extended
[23]	624	* pointer on the associated inode.
	625	* - If a given name in the path is not found in the inode tree, it try to load the missing
	626	* dentry/inode couple, from informations found in the parent directory.
	627	* - If this directory entry does not exist on device, it returns an error.
	628	* - If the the file identified by the pathname does not exist on device but the
	629	* flag CREATE is set, the inode is created.
	630	* - If the the file identified by the pathname exist on device but both flags EXCL
	631	* and CREATE are set, an error is returned.
[1]	632	******************************************************************************************
[23]	633	* @ cwd_xp : extended pointer on current directory (for relative path).
	634	* @ pathname : path in kernel space (can be relative or absolute).
	635	* @ lookup_mode : flags defining the working mode (defined above in this file).
[238]	636	* @ inode_xp : [out] buffer for extended pointer on searched inode.
[23]	637	* @ return 0 if success / ENOENT if inode not found , EACCES if permissopn denied,
	638	* EAGAIN if a new complete lookup must be made
[1]	639	*****************************************************************************************/
[23]	640	error_t vfs_lookup( xptr_t cwd_xp,
	641	char * pathname,
	642	uint32_t lookup_mode,
	643	xptr_t * inode_xp );
[1]	644
	645	/******************************************************************************************
	646	* This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
	647	* It can be executed by any thread running in any cluster, as this function
	648	* uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
[204]	649	* This is done in three steps:
	650	* 1) The dentry is created in the cluster containing the existing <parent_xp> inode.
	651	* The new dentry name is defined by the <name> argument.
	652	* 2) The inode and its associated mapper are created in cluster identified by <child_cxy>.
	653	* The new inode and the parent inode can have different FS types.
[238]	654	* 3) The "child_xp" field in created dentry (pointing on the created inode) is updated.
[1]	655	******************************************************************************************
[188]	656	* @ child_cxy : target cluster for child inode.
[23]	657	* @ inode_type : new inode type
	658	* @ fs_type : new inode FS type.
[1]	659	* @ parent_xp : extended pointer on parent inode.
	660	* @ name : new directory entry name.
[188]	661	* @ extend : fs_type_specific inode extension.
[1]	662	* @ child_xp : [out] buffer for extended pointer on child inode.
[204]	663	* @ return 0 if success / ENOMEM if dentry or inode cannot be created.
[1]	664	*****************************************************************************************/
[188]	665	error_t vfs_add_child_in_parent( cxy_t child_cxy,
	666	vfs_inode_type_t inode_type,
[23]	667	vfs_fs_type_t fs_type,
	668	xptr_t parent_xp,
	669	char * name,
[188]	670	void * extend,
[23]	671	xptr_t * child_xp );
[1]	672
	673	/******************************************************************************************
[23]	674	* This function removes a couple dentry/inode from the Inode-Tree, and remove it from
	675	* the external device.
	676	* TODO
[1]	677	******************************************************************************************
	678	* @ child_xp : extended pointer on removed inode.
	679	*****************************************************************************************/
	680	error_t vfs_remove_child_from_parent( xptr_t child_xp );
	681
[188]	682	/******************************************************************************************
	683	* This recursive function diplays a complete inode/dentry sub-tree.
	684	* Any inode can be selected as the sub-tree root.
[238]	685	* TODO this function is not protected against a concurrent inode/dentry removal...
[188]	686	******************************************************************************************
	687	* @ inode_xp : extended pointer on sub-tree root inode.
	688	*****************************************************************************************/
	689	void vfs_display( xptr_t inode_xp );
[23]	690
	691
	692
	693
	694
[1]	695	/*****************************************************************************************/
[23]	696	/**************** File access API ****************************************************/
[1]	697	/*****************************************************************************************/
	698
	699	/******************************************************************************************
	700	* This function allocates a vfs_file_t structure in the cluster containing the inode
[23]	701	* associated to the file identified by <cwd_xp> & <path>.
	702	* It initializes it, register it in the reference process fd_array, and returns both
	703	* the extended pointer on the remote file descriptor, and the index in the fd_array.
[1]	704	* The pathname can be relative to current directory or absolute.
[23]	705	* If the inode does not exist in the inode cache, it try to find the file on the mounted
[1]	706	* device, and creates an inode on a pseudo randomly selected cluster if found.
	707	* It the requested file does not exist on device, it creates a new inode if the
	708	* O_CREAT flag is set and return an error otherwise.
	709	******************************************************************************************
[23]	710	* @ cwd_xp : extended pointer on current working directory file descriptor.
	711	* @ path : file pathname (absolute or relative to current directory).
	712	* @ flags : defined above
	713	* @ mode : access rights (as defined by chmod)
	714	* @ file_xp : [out] buffer for extended pointer on created remote file descriptor.
	715	* @ file_id : [out] buffer for created file descriptor index in reference fd_array.
[1]	716	* @ return 0 if success / return non-zero if error.
	717	*****************************************************************************************/
	718	error_t vfs_open( xptr_t cwd_xp,
	719	char * path,
	720	uint32_t flags,
[23]	721	uint32_t mode,
	722	xptr_t * file_xp,
	723	uint32_t * file_id );
[1]	724
	725	/******************************************************************************************
[23]	726	* This function moves <size> bytes between the file identified by the open file descriptor
	727	* <file_xp> and a local kernel <buffer> , taken into account the offset in <file_xp>.
	728	* The transfer direction is defined by the <to_buffer> argument.
	729	******************************************************************************************
	730	* @ to_buffer : mapper -> buffer if true / buffer->mapper if false.
	731	* @ file_xp : extended pointer on the remote file descriptor.
	732	* @ buffer : local pointer on local kernel buffer.
[1]	733	* @ size : requested number of bytes from offset.
	734	* @ returns number of bytes actually transfered / -1 if error.
	735	*****************************************************************************************/
[23]	736	error_t vfs_move( bool_t to_buffer,
	737	xptr_t file_xp,
	738	void * buffer,
	739	uint32_t size );
[1]	740
	741	/******************************************************************************************
	742	* This function set a new value in the offset of the open file descriptor <file_xp>.
	743	* This value depends on the <whence> argument:
	744	* - if VFS_SEEK_SET, new value is <offset>
	745	* - if VFS_SEEK_CUR, new value is current_offset + <offset>
	746	* - if VFS_SEEK_END, new value is file_size + <offset>
	747	******************************************************************************************
	748	* @ file_xp : extended pointer on the remote open file descriptor.
	749	* @ offset : local pointer on source kernel buffer.
	750	* @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
	751	* @ new_offset : [out] buffer for new offset value.
	752	* @ returns 0 if success / -1 if error.
	753	*****************************************************************************************/
	754	error_t vfs_lseek( xptr_t file_xp,
	755	uint32_t offset,
	756	uint32_t whence,
	757	uint32_t * new_offset );
	758
	759	/******************************************************************************************
[23]	760	* This function close an open file descriptor:
	761	* 1) All entries in fd_array copies are directly cancelled by the calling thread,
	762	* using remote accesses.
	763	* 2) The memory allocated to file descriptor in cluster containing the inode is released.
	764	* It requires a RPC if cluster containing the file descriptor is remote.
[1]	765	******************************************************************************************
	766	* @ file_xp : extended pointer on the file descriptor.
[23]	767	* @ file_id : file descriptor index in fd_array.
	768	* @ returns 0 if success / -1 if error.
[1]	769	*****************************************************************************************/
[23]	770	error_t vfs_close( xptr_t file_xp,
	771	uint32_t file_id );
[1]	772
	773	/******************************************************************************************
[23]	774	* This function remove from the file system a directory entry identified by the
	775	* <cwd_xp> & <path> arguments.
[1]	776	******************************************************************************************
[23]	777	* @ cwd_xp : extended pointer on the current working directory file descriptor.
[1]	778	* @ path : pathname (absolute or relative to current directory).
[23]	779	* @ returns 0 if success / -1 if error.
[1]	780	*****************************************************************************************/
	781	error_t vfs_unlink( xptr_t cwd_xp,
	782	char * path );
	783
	784	/******************************************************************************************
[23]	785	* This function returns, in the structure pointed by the <k_stat> kernel pointer,
	786	* various informations on the file descriptor identified by the <file_xp> argument.
	787	* TODO not implemented yet...
	788	******************************************************************************************
	789	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	790	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	791	* @ returns 0 if success / -1 if error.
[1]	792	*****************************************************************************************/
	793	error_t vfs_stat( xptr_t file_xp,
[23]	794	vfs_stat_t * k_stat );
[1]	795
	796	/******************************************************************************************
[23]	797	* This function returns, in the structure pointed by the <k_dirent> kernel pointer,
	798	* various infos on the directory entry currently pointed by the <file_xp> file descriptor.
	799	* TODO not implemented yet...
	800	******************************************************************************************
	801	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	802	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	803	* @ returns 0 if success / -1 if error.
[1]	804	*****************************************************************************************/
[23]	805	error_t vfs_readdir( xptr_t file_xp,
	806	vfs_dirent_t * k_dirent );
[1]	807
	808	/******************************************************************************************
[23]	809	* This function creates a new inode and associated dentry for the directory defined
	810	* by the <cwd_xp> & <path> arguments.
	811	* TODO not implemented yet...
	812	******************************************************************************************
	813	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	814	* @ path : pathname (absolute or relative to current directory).
	815	* @ mode : access rights (as defined by chmod)
	816	* @ returns 0 if success / -1 if error.
[1]	817	*****************************************************************************************/
[23]	818	error_t vfs_mkdir( xptr_t cwd_xp,
	819	char * path,
	820	uint32_t mode );
[1]	821
	822	/******************************************************************************************
[23]	823	* This function remove a directory identified by the <cwd_xp / path> arguments
	824	* from the file system.
	825	* TODO not implemented yet...
	826	******************************************************************************************
	827	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	828	* @ path : pathname (absolute or relative to current directory).
	829	* @ returns 0 if success / -1 if error.
[1]	830	*****************************************************************************************/
[23]	831	error_t vfs_rmdir( xptr_t cwd_xp,
	832	char * path );
[1]	833
	834	/******************************************************************************************
[23]	835	* This function makes the directory identified by <cwd_xp / path> arguments to become
	836	* the working directory for the calling process.
	837	******************************************************************************************
	838	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	839	* @ path : file pathname (absolute or relative to current directory).
	840	* return 0 if success / -1 if error.
[1]	841	*****************************************************************************************/
[23]	842	error_t vfs_chdir( xptr_t cwd_xp,
	843	char * path );
[1]	844
	845	/******************************************************************************************
[23]	846	* This function change the access rigths for the file identified by the <cwd_xp / path>
	847	* arguments. The new access rights are defined by the <mode> argument value.
	848	******************************************************************************************
	849	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	850	* @ path : file pathname (absolute or relative to current directory).
	851	* @ mode : access rights new value.
	852	* return 0 if success / -1 if error.
[1]	853	*****************************************************************************************/
[23]	854	error_t vfs_chmod( xptr_t cwd_xp,
	855	char * path,
	856	uint32_t mode );
[1]	857
	858	/******************************************************************************************
[23]	859	* This function creates a named FIFO file.
	860	* TODO not implemented yet
	861	******************************************************************************************
	862	* @ path : FIFO pathname (absolute or relative to current directory).
	863	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	864	* @ mode : access rights new value.
[1]	865	*****************************************************************************************/
[23]	866	error_t vfs_mkfifo( xptr_t cwd_xp,
	867	char * path,
	868	uint32_t mode );
[1]	869
	870
	871	/*****************************************************************************************/
[23]	872	/**************** Mapper access API **************************************************/
[1]	873	/*****************************************************************************************/
	874
[23]	875	/******************************************************************************************
[238]	876	* This function makes an I/O operation to move one page to/from device from/to the mapper.
	877	* It is used in case of MISS on the mapper, or when a dirty page in the mapper must
	878	* be updated in the File System.
[23]	879	* Depending on the file system type, it calls the proper, FS specific function.
	880	* It must be executed by a thread running in the cluster containing the mapper.
	881	* The mapper pointer is obtained from the page descriptor.
	882	* It takes the mapper lock before launching the IO operation.
	883	******************************************************************************************
[238]	884	* @ page : local pointer on the page descriptor.
	885	* @ to_mapper : transfer direction.
[23]	886	* @ returns 0 if success / return EINVAL if it cannot access the external device.
[1]	887	*****************************************************************************************/
[238]	888	error_t vfs_mapper_move_page( struct page_s * page,
	889	bool_t to_mapper );
[1]	890
[23]	891	/******************************************************************************************
[239]	892	* This function makes I/O operations to move, from device to mapper, all pages covering
	893	* a given inode, identified by the <inode> argument. Inode be a directory or a file,
	894	* but this function is mainly used to load (prefetch) a complete directory to the mapper.
[23]	895	* Depending on the file system type, it calls the proper, FS specific function.
	896	* It must be executed by a thread running in the cluster containing the mapper.
[238]	897	* The mapper pointer is obtained from the inode descriptor.
[23]	898	* It takes the mapper lock before launching the IO operation.
	899	******************************************************************************************
[238]	900	* @ inode : local pointer on inode.
	901	* @ return 0 if success / return EIO if device access failure.
[1]	902	*****************************************************************************************/
[238]	903	error_t vfs_mapper_load_all( vfs_inode_t * inode );
[1]	904
	905
	906
[23]	907	/* deprecated [AG]
	908
	909	typedef error_t (lookup_inode_t) ( vfs_inode_t * parent ,
	910	vfs_dentry_t * dentry );
	911
	912	typedef error_t (write_inode_t) ( vfs_inode_t * inode );
	913
	914	typedef error_t (release_inode_t) ( vfs_inode_t * inode );
	915
	916	typedef error_t (unlink_inode_t) ( vfs_inode_t * parent,
	917	vfs_dentry_t * dentry,
	918	uint32_t flags );
	919
	920	typedef error_t (stat_inode_t) ( vfs_inode_t * inode );
	921
	922	typedef error_t (trunc_inode_t) ( vfs_inode_t * inode );
	923
	924	typedef error_t (delete_inode_t) ( vfs_inode_t * inode );
	925
	926	typedef struct vfs_inode_op_s
	927	{
	928	init_inode_t * init;
	929	create_inode_t * create;
	930	lookup_inode_t * lookup;
	931	write_inode_t * write;
	932	release_inode_t * release;
	933	unlink_inode_t * unlink;
	934	delete_inode_t * delete;
	935	stat_inode_t * stat;
	936	trunc_inode_t * trunc; // change the size of a file
	937	}
	938	vfs_inode_op_t;
	939
	940	******************************************************************************************
	941	* These typedef define the set of FS specific operations on a VFS DENTRY descriptor.
	942	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	943	* This code is not actually used, and is only defined for documentation
	944	******************************************************************************************
	945
	946
	947	typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
	948
	949	typedef struct vfs_dentry_op_s
	950	{
	951	vfs_compare_dentry_t * compare;
	952	}
	953	vfs_dentry_op_t;
	954
	955
	956	******************************************************************************************
	957	* These typedef define the set of FS specific operations on FILE descriptors
	958	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	959	* This code is not actually used, and is only defined for documentation
	960	******************************************************************************************
	961
	962
	963	typedef error_t (open_file_t ) ( vfs_file_t * file,
	964	void * extend );
	965
	966	typedef error_t (read_file_t ) ( vfs_file_t * file,
	967	char * buffer,
	968	uint32_t count );
	969
	970	typedef error_t (write_file_t ) ( vfs_file_t * file,
	971	char * buffer,
	972	uint32_t count );
	973
	974	typedef error_t (lseek_file_t ) ( vfs_file_t * file );
	975
	976	typedef error_t (close_file_t ) ( vfs_file_t * file );
	977
	978	typedef error_t (release_file_t) ( vfs_file_t * file );
	979
	980	typedef error_t (read_dir_t ) ( vfs_file_t * file );
	981
	982	typedef error_t (mmap_file_t ) ( vfs_file_t * file ,
	983	struct vseg_s * vseg );
	984
	985	typedef error_t (munmap_file_t ) ( vfs_file_t * file,
	986	struct vseg_s * vseg );
	987
	988	typedef struct vfs_file_op_s
	989	{
	990	open_file_t * open;
	991	read_file_t * read;
	992	write_file_t * write;
	993	lseek_file_t * lseek;
	994	read_dir_t * readdir;
	995	close_file_t * close;
	996	release_file_t * release;
	997	mmap_file_t * mmap;
	998	munmap_file_t * munmap;
	999	}
	1000	vfs_file_op_t;
	1001
	1002	*/
	1003
[1]	1004	#endif /* _VFS_H_ */

Note: See TracBrowser for help on using the repository browser.

Download in other formats: