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vfs.h @ 231

Last change on this file since 231 was 204, checked in by alain, 7 years ago

Bug fix in kernel_init
-This line, and those below, will be ignored--

M params.mk
M kernel_config.h
M Makefile
M hdd/virt_hdd.dmg
M tools/bootloader_tsar/boot.c
M kernel/libk/bits.h
M kernel/libk/elf.c
M kernel/libk/xhtab.c
M kernel/libk/elf.h
M kernel/libk/xhtab.h
M kernel/devices/dev_pic.c
M kernel/mm/vmm.c
M kernel/mm/mapper.c
M kernel/mm/mapper.h
M kernel/vfs/devfs.h
M kernel/vfs/vfs.c
M kernel/vfs/vfs.h
M kernel/vfs/devfs.c
M kernel/kern/chdev.h
M kernel/kern/kernel_init.c
M kernel/kern/process.c
M kernel/kern/process.h
M hal/tsar_mips32/core/hal_remote.c
M hal/tsar_mips32/drivers/soclib_pic.c

File size: 52.0 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	/******************************************************************************************
[204]	452	* This debug function diplays the name of the inode identified by the <inode_xp>
	453	* argument, and all children names for a directory.
	454	*****************************************************************************************
	455	* @ inode_xp : extended pointer on the remote inode.
	456	*****************************************************************************************/
	457	void vfs_inode_display( xptr_t inode_xp );
	458
	459
	460
	461
	462
	463
	464	/******************************************************************************************
[1]	465	* This function TODO
	466	*****************************************************************************************/
	467	error_t vfs_inode_trunc( vfs_inode_t * inode );
	468
	469	/******************************************************************************************
	470	* This function TODO
	471	*****************************************************************************************/
	472	error_t vfs_inode_link( vfs_inode_t * inode,
	473	uint32_t igc );
	474
	475	/******************************************************************************************
	476	* This function TODO
	477	*****************************************************************************************/
	478	error_t vfs_inode_unlink( vfs_inode_t * inode );
	479
	480	/******************************************************************************************
	481	* This function TODO
	482	*****************************************************************************************/
	483	error_t vfs_inode_stat( vfs_inode_t * inode,
	484	uint32_t inum );
	485
	486	/******************************************************************************************
	487	* This function TODO
	488	*****************************************************************************************/
	489	error_t vfs_icache_del( vfs_inode_t * inode );
	490
	491
	492	/******************************************************************************************
	493	* This function TODO Pourquoi 2 arguments ?
	494	*****************************************************************************************/
	495	error_t vfs_stat_inode( vfs_inode_t * inode,
	496	uint32_t inum );
	497
	498
	499	/*****************************************************************************************/
	500	/*************** Dentry related functions ********************************************/
	501	/*****************************************************************************************/
	502
	503	/******************************************************************************************
	504	* This function allocates memory from local cluster for a dentry descriptor,
	505	* initialises it from arguments values, and returns the extended pointer on dentry.
	506	* The inode field is not initialized, because the inode does not exist yet.
	507	* If the client thread is not running in the target cluster for this inode,
	508	* it must use the rpc_dentry_create_client() function.
	509	******************************************************************************************
[23]	510	* @ fs_type : file system type.
[1]	511	* @ name : directory entry file/dir name.
	512	* @ parent : local pointer on parent inode.
[23]	513	* @ dentry_xp : [out] buffer for extended pointer on created dentry.
[1]	514	* @ return 0 if success / return ENOMEM or EINVAL if error.
	515	*****************************************************************************************/
[23]	516	error_t vfs_dentry_create( vfs_fs_type_t fs_type,
	517	char * name,
	518	vfs_inode_t * parent,
	519	xptr_t * dentry_xp );
[1]	520
	521	/******************************************************************************************
	522	* This function releases memory allocated to a dentry descriptor.
	523	* It must be executed by a thread running in the cluster containing the dentry,
	524	* and the dentry refcount must be zero.
	525	* If the client thread is not running in the owner cluster, it must use the
	526	* rpc_dentry_destroy_client() function.
	527	******************************************************************************************
	528	* @ dentry : local pointer on dentry descriptor.
	529	*****************************************************************************************/
	530	void vfs_dentry_destroy( vfs_dentry_t * dentry );
	531
	532	/******************************************************************************************
[23]	533	* These functions atomically increment/decrement the dentry refcount.
[1]	534	* It can be called by any thread running in any cluster.
	535	*****************************************************************************************/
	536	void vfs_dentry_remote_up( xptr_t dentry_xp );
[23]	537	void vfs_dentry_remote_down( xptr_t dentry_xp );
[1]	538
[23]	539
	540	/*****************************************************************************************/
	541	/********************** File descriptor related functions ****************************/
	542	/*****************************************************************************************/
	543
[1]	544	/******************************************************************************************
[23]	545	* This function allocates memory and initializes a new local file descriptor.
	546	* It must be executed in the cluster containing the inode.
	547	* If the client thread is not running in the owner cluster, it must use the
	548	* rpc_vfs_file_create_client() function.
	549	******************************************************************************************
	550	* @ inode : local pointer on associated inode.
	551	* @ attr : file descriptor attributes.
	552	* @ file_xp : [out] buffer for extended pointer on created file descriptor.
	553	* @ return 0 if success / return ENOMEM if error.
[1]	554	*****************************************************************************************/
[23]	555	error_t vfs_file_create( vfs_inode_t * inode,
	556	uint32_t attr,
	557	xptr_t * file_xp );
[1]	558
[23]	559	/******************************************************************************************
	560	* This function releases memory allocated to a local file descriptor.
	561	* It must be executed by a thread running in the cluster containing the inode,
	562	* and the file refcount must be zero.
	563	* If the client thread is not running in the owner cluster, it must use the
	564	* rpc_vfs_file_destroy_client() function.
	565	******************************************************************************************
	566	* @ file : local pointer on file descriptor.
	567	*****************************************************************************************/
	568	void vfs_file_destroy( vfs_file_t * file );
[1]	569
[23]	570	/******************************************************************************************
	571	* These functions increment (resp. decrement) the count field in a remote file
	572	* descriptor, using a remote_atomic access.
	573	*****************************************************************************************/
	574	void vfs_file_count_up ( xptr_t file_xp );
	575	void vfs_file_count_down( xptr_t file_xp );
	576
	577
	578
[1]	579	/*****************************************************************************************/
[23]	580	/***************** Inode-Tree related functions **************************************/
[1]	581	/*****************************************************************************************/
	582
	583	/******************************************************************************************
[188]	584	* This function randomly selects a cluster for a new inode.
	585	******************************************************************************************
	586	* @ returns the selected cluster identifier.
	587	*****************************************************************************************/
	588	cxy_t vfs_cluster_random_select();
	589
	590	/******************************************************************************************
[1]	591	* This function returns in a kernel buffer allocated by the caller function,
	592	* the pathname of a file/dir identified by an extended pointer on the inode.
	593	* It traverse the Inode Tree from the target node to the root.
	594	* It can be called by any thread running in any cluster.
	595	******************************************************************************************
	596	* @ inode_xp : pointer on inode descriptor.
	597	* @ buffer : kernel buffer for pathname (must be allocated by caller).
	598	* @ size : max number of characters in buffer.
	599	* @ return 0 if success / return EINVAL if buffer too small.
	600	*****************************************************************************************/
	601	error_t vfs_get_path( xptr_t inode_xp,
	602	char * buffer,
	603	uint32_t max_size );
	604
	605	/******************************************************************************************
	606	* This function takes a pathname (absolute or relative to cwd) and returns an extended
[23]	607	* pointer on the associated inode.
	608	* - If a given name in the path is not found in the inode tree, it try to load the missing
	609	* dentry/inode couple, from informations found in the parent directory.
	610	* - If this directory entry does not exist on device, it returns an error.
	611	* - If the the file identified by the pathname does not exist on device but the
	612	* flag CREATE is set, the inode is created.
	613	* - If the the file identified by the pathname exist on device but both flags EXCL
	614	* and CREATE are set, an error is returned.
[1]	615	******************************************************************************************
[23]	616	* @ cwd_xp : extended pointer on current directory (for relative path).
	617	* @ pathname : path in kernel space (can be relative or absolute).
	618	* @ lookup_mode : flags defining the working mode (defined above in this file).
	619	* @ inode_xp : [out] buffer for extended pointer on inode.
	620	* @ return 0 if success / ENOENT if inode not found , EACCES if permissopn denied,
	621	* EAGAIN if a new complete lookup must be made
[1]	622	*****************************************************************************************/
[23]	623	error_t vfs_lookup( xptr_t cwd_xp,
	624	char * pathname,
	625	uint32_t lookup_mode,
	626	xptr_t * inode_xp );
[1]	627
	628	/******************************************************************************************
	629	* This function creates a new couple dentry/inode, and insert it in the Inode-Tree.
	630	* It can be executed by any thread running in any cluster, as this function
	631	* uses the rpc_dentry_create_client() and rpc_inode_create client() if required.
[204]	632	* This is done in three steps:
	633	* 1) The dentry is created in the cluster containing the existing <parent_xp> inode.
	634	* The new dentry name is defined by the <name> argument.
	635	* 2) The inode and its associated mapper are created in cluster identified by <child_cxy>.
	636	* The new inode and the parent inode can have different FS types.
	637	* 3) The "child_xp" field in created dentry (pointing on thecreated inode) is updated.
[1]	638	******************************************************************************************
[188]	639	* @ child_cxy : target cluster for child inode.
[23]	640	* @ inode_type : new inode type
	641	* @ fs_type : new inode FS type.
[1]	642	* @ parent_xp : extended pointer on parent inode.
	643	* @ name : new directory entry name.
[188]	644	* @ extend : fs_type_specific inode extension.
[1]	645	* @ child_xp : [out] buffer for extended pointer on child inode.
[204]	646	* @ return 0 if success / ENOMEM if dentry or inode cannot be created.
[1]	647	*****************************************************************************************/
[188]	648	error_t vfs_add_child_in_parent( cxy_t child_cxy,
	649	vfs_inode_type_t inode_type,
[23]	650	vfs_fs_type_t fs_type,
	651	xptr_t parent_xp,
	652	char * name,
[188]	653	void * extend,
[23]	654	xptr_t * child_xp );
[1]	655
	656	/******************************************************************************************
[23]	657	* This function removes a couple dentry/inode from the Inode-Tree, and remove it from
	658	* the external device.
	659	* TODO
[1]	660	******************************************************************************************
	661	* @ child_xp : extended pointer on removed inode.
	662	*****************************************************************************************/
	663	error_t vfs_remove_child_from_parent( xptr_t child_xp );
	664
[188]	665	/******************************************************************************************
	666	* This recursive function diplays a complete inode/dentry sub-tree.
	667	* Any inode can be selected as the sub-tree root.
	668	* TODO this function is not ptotected against a concurrent node removal...
	669	******************************************************************************************
	670	* @ inode_xp : extended pointer on sub-tree root inode.
	671	*****************************************************************************************/
	672	void vfs_display( xptr_t inode_xp );
[23]	673
	674
	675
	676
	677
[1]	678	/*****************************************************************************************/
[23]	679	/**************** File access API ****************************************************/
[1]	680	/*****************************************************************************************/
	681
	682	/******************************************************************************************
	683	* This function allocates a vfs_file_t structure in the cluster containing the inode
[23]	684	* associated to the file identified by <cwd_xp> & <path>.
	685	* It initializes it, register it in the reference process fd_array, and returns both
	686	* the extended pointer on the remote file descriptor, and the index in the fd_array.
[1]	687	* The pathname can be relative to current directory or absolute.
[23]	688	* If the inode does not exist in the inode cache, it try to find the file on the mounted
[1]	689	* device, and creates an inode on a pseudo randomly selected cluster if found.
	690	* It the requested file does not exist on device, it creates a new inode if the
	691	* O_CREAT flag is set and return an error otherwise.
	692	******************************************************************************************
[23]	693	* @ cwd_xp : extended pointer on current working directory file descriptor.
	694	* @ path : file pathname (absolute or relative to current directory).
	695	* @ flags : defined above
	696	* @ mode : access rights (as defined by chmod)
	697	* @ file_xp : [out] buffer for extended pointer on created remote file descriptor.
	698	* @ file_id : [out] buffer for created file descriptor index in reference fd_array.
[1]	699	* @ return 0 if success / return non-zero if error.
	700	*****************************************************************************************/
	701	error_t vfs_open( xptr_t cwd_xp,
	702	char * path,
	703	uint32_t flags,
[23]	704	uint32_t mode,
	705	xptr_t * file_xp,
	706	uint32_t * file_id );
[1]	707
	708	/******************************************************************************************
[23]	709	* This function moves <size> bytes between the file identified by the open file descriptor
	710	* <file_xp> and a local kernel <buffer> , taken into account the offset in <file_xp>.
	711	* The transfer direction is defined by the <to_buffer> argument.
	712	******************************************************************************************
	713	* @ to_buffer : mapper -> buffer if true / buffer->mapper if false.
	714	* @ file_xp : extended pointer on the remote file descriptor.
	715	* @ buffer : local pointer on local kernel buffer.
[1]	716	* @ size : requested number of bytes from offset.
	717	* @ returns number of bytes actually transfered / -1 if error.
	718	*****************************************************************************************/
[23]	719	error_t vfs_move( bool_t to_buffer,
	720	xptr_t file_xp,
	721	void * buffer,
	722	uint32_t size );
[1]	723
	724	/******************************************************************************************
	725	* This function set a new value in the offset of the open file descriptor <file_xp>.
	726	* This value depends on the <whence> argument:
	727	* - if VFS_SEEK_SET, new value is <offset>
	728	* - if VFS_SEEK_CUR, new value is current_offset + <offset>
	729	* - if VFS_SEEK_END, new value is file_size + <offset>
	730	******************************************************************************************
	731	* @ file_xp : extended pointer on the remote open file descriptor.
	732	* @ offset : local pointer on source kernel buffer.
	733	* @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END.
	734	* @ new_offset : [out] buffer for new offset value.
	735	* @ returns 0 if success / -1 if error.
	736	*****************************************************************************************/
	737	error_t vfs_lseek( xptr_t file_xp,
	738	uint32_t offset,
	739	uint32_t whence,
	740	uint32_t * new_offset );
	741
	742	/******************************************************************************************
[23]	743	* This function close an open file descriptor:
	744	* 1) All entries in fd_array copies are directly cancelled by the calling thread,
	745	* using remote accesses.
	746	* 2) The memory allocated to file descriptor in cluster containing the inode is released.
	747	* It requires a RPC if cluster containing the file descriptor is remote.
[1]	748	******************************************************************************************
	749	* @ file_xp : extended pointer on the file descriptor.
[23]	750	* @ file_id : file descriptor index in fd_array.
	751	* @ returns 0 if success / -1 if error.
[1]	752	*****************************************************************************************/
[23]	753	error_t vfs_close( xptr_t file_xp,
	754	uint32_t file_id );
[1]	755
	756	/******************************************************************************************
[23]	757	* This function remove from the file system a directory entry identified by the
	758	* <cwd_xp> & <path> arguments.
[1]	759	******************************************************************************************
[23]	760	* @ cwd_xp : extended pointer on the current working directory file descriptor.
[1]	761	* @ path : pathname (absolute or relative to current directory).
[23]	762	* @ returns 0 if success / -1 if error.
[1]	763	*****************************************************************************************/
	764	error_t vfs_unlink( xptr_t cwd_xp,
	765	char * path );
	766
	767	/******************************************************************************************
[23]	768	* This function returns, in the structure pointed by the <k_stat> kernel pointer,
	769	* various informations on the file descriptor identified by the <file_xp> argument.
	770	* TODO not implemented yet...
	771	******************************************************************************************
	772	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	773	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	774	* @ returns 0 if success / -1 if error.
[1]	775	*****************************************************************************************/
	776	error_t vfs_stat( xptr_t file_xp,
[23]	777	vfs_stat_t * k_stat );
[1]	778
	779	/******************************************************************************************
[23]	780	* This function returns, in the structure pointed by the <k_dirent> kernel pointer,
	781	* various infos on the directory entry currently pointed by the <file_xp> file descriptor.
	782	* TODO not implemented yet...
	783	******************************************************************************************
	784	* @ file_xp : extended pointer on the file descriptor of the searched directory .
	785	* @ k_dirent : local pointer on the dirent_t structure in kernel space.
	786	* @ returns 0 if success / -1 if error.
[1]	787	*****************************************************************************************/
[23]	788	error_t vfs_readdir( xptr_t file_xp,
	789	vfs_dirent_t * k_dirent );
[1]	790
	791	/******************************************************************************************
[23]	792	* This function creates a new inode and associated dentry for the directory defined
	793	* by the <cwd_xp> & <path> arguments.
	794	* TODO not implemented yet...
	795	******************************************************************************************
	796	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	797	* @ path : pathname (absolute or relative to current directory).
	798	* @ mode : access rights (as defined by chmod)
	799	* @ returns 0 if success / -1 if error.
[1]	800	*****************************************************************************************/
[23]	801	error_t vfs_mkdir( xptr_t cwd_xp,
	802	char * path,
	803	uint32_t mode );
[1]	804
	805	/******************************************************************************************
[23]	806	* This function remove a directory identified by the <cwd_xp / path> arguments
	807	* from the file system.
	808	* TODO not implemented yet...
	809	******************************************************************************************
	810	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	811	* @ path : pathname (absolute or relative to current directory).
	812	* @ returns 0 if success / -1 if error.
[1]	813	*****************************************************************************************/
[23]	814	error_t vfs_rmdir( xptr_t cwd_xp,
	815	char * path );
[1]	816
	817	/******************************************************************************************
[23]	818	* This function makes the directory identified by <cwd_xp / path> arguments to become
	819	* the working directory for the calling process.
	820	******************************************************************************************
	821	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	822	* @ path : file pathname (absolute or relative to current directory).
	823	* return 0 if success / -1 if error.
[1]	824	*****************************************************************************************/
[23]	825	error_t vfs_chdir( xptr_t cwd_xp,
	826	char * path );
[1]	827
	828	/******************************************************************************************
[23]	829	* This function change the access rigths for the file identified by the <cwd_xp / path>
	830	* arguments. The new access rights are defined by the <mode> argument value.
	831	******************************************************************************************
	832	* @ cwd_xp : extended pointer on current directory file descriptor (relative path).
	833	* @ path : file pathname (absolute or relative to current directory).
	834	* @ mode : access rights new value.
	835	* return 0 if success / -1 if error.
[1]	836	*****************************************************************************************/
[23]	837	error_t vfs_chmod( xptr_t cwd_xp,
	838	char * path,
	839	uint32_t mode );
[1]	840
	841	/******************************************************************************************
[23]	842	* This function creates a named FIFO file.
	843	* TODO not implemented yet
	844	******************************************************************************************
	845	* @ path : FIFO pathname (absolute or relative to current directory).
	846	* @ cwd_xp : extended pointer on the current working directory file descriptor.
	847	* @ mode : access rights new value.
[1]	848	*****************************************************************************************/
[23]	849	error_t vfs_mkfifo( xptr_t cwd_xp,
	850	char * path,
	851	uint32_t mode );
[1]	852
	853
	854	/*****************************************************************************************/
[23]	855	/**************** Mapper access API **************************************************/
[1]	856	/*****************************************************************************************/
	857
[23]	858	/******************************************************************************************
	859	* This function makes an I/O operation to move one page from VFS to a given mapper,
	860	* in case of MISS on the mapper cache.
	861	* Depending on the file system type, it calls the proper, FS specific function.
	862	* It must be executed by a thread running in the cluster containing the mapper.
	863	* The mapper pointer is obtained from the page descriptor.
	864	* It takes the mapper lock before launching the IO operation.
	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_to_mapper( struct page_s * page );
[1]	870
[23]	871	/******************************************************************************************
	872	* This function makes an I/0 operation to move one page from a given mapper to VFS,
	873	* when a dirty page in the mapper cache must be updated in the File System.
	874	* Depending on the file system type, it calls the proper, FS specific function.
	875	* It must be executed by a thread running in the cluster containing the mapper.
	876	* The mapper pointer is obtained from the page descriptor.
	877	* It takes the mapper lock before launching the IO operation.
	878	* It does nothing if the page is not dirty. If the page is dirty, it clear the page
	879	* dirty bit, and remove the page from the PPM dirty list.
	880	******************************************************************************************
	881	* @ page : local pointer on the page descriptor.
	882	* @ returns 0 if success / return EINVAL if it cannot access the external device.
[1]	883	*****************************************************************************************/
[23]	884	error_t vfs_move_page_from_mapper( struct page_s * page );
[1]	885
	886
	887
	888
[23]	889
	890
	891	///////////////////////////////////////////////////////////////////////////////////////////
	892	// These typedef define the FS specific operations that must be implemented by any
	893	// specific file system to be supported by the ALMOS_MKH VFS.
	894	// These typedef are not actually used, and are only defined for documentation
	895	///////////////////////////////////////////////////////////////////////////////////////////
	896
	897	typedef error_t (fs_init_t) ( xptr_t vfs_root_xp );
	898
	899	typedef error_t (fs_inode_extend_t) ( struct vfs_inode_s * inode,
	900	void * extend );
	901
	902	typedef void (fs_inode_release_t) ( struct vfs_inode_s * inode );
	903
	904	typedef error_t (fs_write_page_t) ( struct page_s * page );
	905
	906	typedef error_t (fs_read_page_t) ( struct page_s * page );
	907
	908
	909
	910
	911
	912
	913
	914
	915	/* deprecated [AG]
	916
	917	typedef error_t (lookup_inode_t) ( vfs_inode_t * parent ,
	918	vfs_dentry_t * dentry );
	919
	920	typedef error_t (write_inode_t) ( vfs_inode_t * inode );
	921
	922	typedef error_t (release_inode_t) ( vfs_inode_t * inode );
	923
	924	typedef error_t (unlink_inode_t) ( vfs_inode_t * parent,
	925	vfs_dentry_t * dentry,
	926	uint32_t flags );
	927
	928	typedef error_t (stat_inode_t) ( vfs_inode_t * inode );
	929
	930	typedef error_t (trunc_inode_t) ( vfs_inode_t * inode );
	931
	932	typedef error_t (delete_inode_t) ( vfs_inode_t * inode );
	933
	934	typedef struct vfs_inode_op_s
	935	{
	936	init_inode_t * init;
	937	create_inode_t * create;
	938	lookup_inode_t * lookup;
	939	write_inode_t * write;
	940	release_inode_t * release;
	941	unlink_inode_t * unlink;
	942	delete_inode_t * delete;
	943	stat_inode_t * stat;
	944	trunc_inode_t * trunc; // change the size of a file
	945	}
	946	vfs_inode_op_t;
	947
	948	******************************************************************************************
	949	* These typedef define the set of FS specific operations on a VFS DENTRY descriptor.
	950	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	951	* This code is not actually used, and is only defined for documentation
	952	******************************************************************************************
	953
	954
	955	typedef error_t (vfs_compare_dentry_t) ( char * first , char * second );
	956
	957	typedef struct vfs_dentry_op_s
	958	{
	959	vfs_compare_dentry_t * compare;
	960	}
	961	vfs_dentry_op_t;
	962
	963
	964	******************************************************************************************
	965	* These typedef define the set of FS specific operations on FILE descriptors
	966	* They must be implemented by any specific file system to be supported by ALMOS_MKH.
	967	* This code is not actually used, and is only defined for documentation
	968	******************************************************************************************
	969
	970
	971	typedef error_t (open_file_t ) ( vfs_file_t * file,
	972	void * extend );
	973
	974	typedef error_t (read_file_t ) ( vfs_file_t * file,
	975	char * buffer,
	976	uint32_t count );
	977
	978	typedef error_t (write_file_t ) ( vfs_file_t * file,
	979	char * buffer,
	980	uint32_t count );
	981
	982	typedef error_t (lseek_file_t ) ( vfs_file_t * file );
	983
	984	typedef error_t (close_file_t ) ( vfs_file_t * file );
	985
	986	typedef error_t (release_file_t) ( vfs_file_t * file );
	987
	988	typedef error_t (read_dir_t ) ( vfs_file_t * file );
	989
	990	typedef error_t (mmap_file_t ) ( vfs_file_t * file ,
	991	struct vseg_s * vseg );
	992
	993	typedef error_t (munmap_file_t ) ( vfs_file_t * file,
	994	struct vseg_s * vseg );
	995
	996	typedef struct vfs_file_op_s
	997	{
	998	open_file_t * open;
	999	read_file_t * read;
	1000	write_file_t * write;
	1001	lseek_file_t * lseek;
	1002	read_dir_t * readdir;
	1003	close_file_t * close;
	1004	release_file_t * release;
	1005	mmap_file_t * mmap;
	1006	munmap_file_t * munmap;
	1007	}
	1008	vfs_file_op_t;
	1009
	1010	*/
	1011
[1]	1012	#endif /* _VFS_H_ */

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