/* * vfs.h - Virtual File System definition. * * Author Mohamed Lamine Karaoui (2014,2015) * Alain Greiner (2016,2017) * * Copyright (c) UPMC Sorbonne Universites * * This file is part of ALMOS-MKH. * * ALMOS-MKH is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2.0 of the License. * * ALMOS-MKH is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with ALMOS-MKH; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef _VFS_H_ #define _VFS_H_ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /**** Forward declarations ***/ struct vfs_inode_s; struct vfs_dentry_t; struct vfs_ctx_t; struct vfs_file_ref_s; struct vfs_file_s; struct vfs_inode_op_s; struct vfs_dentry_op_s; struct vfs_file_op_s; struct vfs_ctx_op_s; struct vfs_lookup_cmd_s; struct vfs_lookup_rsp_s; struct mapper_s; struct process_s; struct device_s; struct vseg_s; struct page_s; /****************************************************************************************** * These flags are used to define the working mode of the vfs_lookup() function. *****************************************************************************************/ #define VFS_LOOKUP_DIR 0x01 /* the searched inode is a directory */ #define VFS_LOOKUP_OPEN 0x02 /* the search is for an open/opendir */ #define VFS_LOOKUP_PARENT 0x04 /* return the parent inode (not the inode itself) */ #define VFS_LOOKUP_CREATE 0x10 /* file must be created if missing */ #define VFS_LOOKUP_EXCL 0x20 /* file cannot previously exist */ /****************************************************************************************** * This define the masks for the POSIX access rights to inodes *****************************************************************************************/ #define VFS_ISUID 0x0004000 #define VFS_ISGID 0x0002000 #define VFS_ISVTX 0x0001000 #define VFS_IRWXU 0x0000700 #define VFS_IRUSR 0x0000400 #define VFS_IWUSR 0x0000200 #define VFS_IXUSR 0x0000100 #define VFS_IRWXG 0x0000070 #define VFS_IRGRP 0x0000040 #define VFS_IWGRP 0x0000020 #define VFS_IXGRP 0x0000010 #define VFS_IRWXO 0x0000007 #define VFS_IROTH 0x0000004 #define VFS_IWOTH 0x0000002 #define VFS_IXOTH 0x0000001 #define VFS_IREAD VFS_IRUSR #define VFS_IWRITE VFS_IWUSR #define VFS_IEXEC VFS_IXUSR /****************************************************************************************** * This structure defines informations common to all inodes and dentries * of a given file system. As it is declared a global variable in the kdata segment, * it is replicated in all clusters and handled as private by each OS intance. *****************************************************************************************/ typedef enum { FS_TYPE_DEVFS = 0, FS_TYPE_FATFS = 1, FS_TYPE_RAMFS = 2, FS_TYPES_NR = 3, } vfs_fs_type_t; typedef enum { CTX_ATTR_READ_ONLY = 0x01, /*! write access prohibited */ CTX_ATTR_SYNC = 0x10, /*! synchronise FS on each write */ } vfs_ctx_attr_t; typedef struct vfs_ctx_s { vfs_fs_type_t type; /*! File System type */ uint32_t attr; /*! global attributes for all files in FS */ uint32_t count; /*! total number of clusters on device */ uint32_t blksize; /*! device cluster size (bytes) */ xptr_t root_xp; /*! extended pointer on root inode */ spinlock_t lock; /*! lock protecting inum allocator */ uint32_t bitmap[BITMAP_SIZE(CONFIG_VFS_MAX_INODES)]; /* inum allocator */ void * extend; /*! FS specific context extension */ } vfs_ctx_t; /****************************************************************************************** * This structure define a VFS inode. * It contains an extended pointer on the parent dentry, and (for directory only) * an hash table xhtab refering all children dentries. * The inode is unique for a directory (not hard links for directories). * For a file, the parent field points to the first dentry who created this inode. * Syncrhonisation: * - the main_lock (spinlock) is used during the inode tree traversal or for inode * modification (add/remove children). * - the data_lock (rwlock) is used during read/write accesses to the data stored * in the mapper. * - the mapper lock (rwlock) is only used during the radix tree traversal to return * the relevant page for read/write. *****************************************************************************************/ /* this enum define the VFS inode types values */ typedef enum { INODE_TYPE_FILE = 0x001, /*! file */ INODE_TYPE_DIR = 0x002, /*! directory */ INODE_TYPE_FIFO = 0x004, /*! POSIX named pipe */ INODE_TYPE_PIPE = 0x008, /*! POSIX anonymous pipe */ INODE_TYPE_SOCKET = 0x010, /*! POSIX socket */ INODE_TYPE_DEV = 0x020, /*! character peripheral channel */ INODE_TYPE_SYML = 0x080, /*! symbolic link */ } vfs_inode_type_t; /* this enum define the VFS inode attributes values */ typedef enum { INODE_ATTR_DIRTY = 0x01, /* modified versus the value on device */ INODE_ATTR_INLOAD = 0x04, /* loading from device in progress */ INODE_ATTR_NEW = 0x08, /* not saved on device yet */ } vfs_inode_attr_t; typedef struct vfs_inode_s { struct vfs_ctx_s * ctx; /*! local pointer on FS context */ uint32_t gc; /*! generation counter */ uint32_t inum; /*! inode identifier (unique in file system) */ uint32_t attr; /*! inode attributes (see above) */ vfs_inode_type_t type; /*! inode type (see above) */ uint32_t size; /*! number of bytes */ uint32_t links; /*! number of alias dentry */ uid_t uid; /*! user owner identifier */ gid_t gid; /*! group owner identifier */ uint32_t rights; /*! access rights */ uint32_t refcount; /*! reference counter (all pointers) */ xptr_t parent_xp; /*! extended pointer on parent dentry */ xhtab_t children; /*! embedded xhtab of vfs_dentry_t */ remote_rwlock_t data_lock; /*! protect read/write to data and to size */ remote_spinlock_t main_lock; /*! protect inode tree traversal and modifs */ list_entry_t list; /*! member of set of inodes in same cluster */ xlist_entry_t wait_root; /*! root of threads waiting on this inode */ struct vfs_inode_op_s * op; /*! TODO ??? */ struct mapper_s * mapper; /*! associated file cache */ void * extend; /*! FS specific inode extension */ } vfs_inode_t; /****************************************************************************************** * This structure defines a directory entry. * A dentry contains the name of a remote file/dir, an extended pointer on the * inode representing this file/dir, and a local pointer on the inode representing * the parent directory. *****************************************************************************************/ typedef struct vfs_dentry_s { struct vfs_ctx_s * ctx; /*! local pointer on FS context */ char name[CONFIG_VFS_MAX_NAME_LENGTH]; uint32_t length; /*! name length (bytes) */ uint32_t refcount; /*! reference counter (all pointers) */ struct vfs_inode_s * parent; /*! local pointer on parent inode */ xptr_t child_xp; /*! extended pointer on child inode */ xlist_entry_t xlist; /*! member of xlist of dentries with same key */ struct vfs_dentry_op_s * op; /*! TODO */ void * extend; /*! FS specific extension */ } vfs_dentry_t; /****************************************************************************************** * This file structure describes an open file/directory for a given process. * It is not replicated, and is dynamically allocated in the cluster that contains * the inode, when a thread makes an open() or opendir() system call. * It cannot exist a file structure without an inode structure. * Aa the fd_array (containing extended pointers on the open file descriptors) * is replicated in all process descriptors, we need a references counter. *****************************************************************************************/ typedef enum { FD_ATTR_READ_ENABLE = 0x01, /*! read access possible */ FD_ATTR_WRITE_ENABLE = 0x02, /*! write access possible */ FD_ATTR_APPEND = 0x04, /*! append on each write */ FD_ATTR_CLOSE_EXEC = 0x08, /*! close file on exec */ FD_ATTR_SYNC = 0x10, /*! synchronise FS on each write */ FD_ATTR_IS_DIR = 0x20, /*! this is a directory */ } vfs_file_attr_t; typedef struct vfs_file_s { struct vfs_ctx_s * ctx; /*! local pointer on FS context. */ uint32_t gc; /*! generation counter */ vfs_file_attr_t attr; /*! file attributes bit vector (see above) */ vfs_inode_type_t type; /*! same type as inode */ uint32_t offset; /*! seek position in file */ uint32_t refcount; /*! all pointers on this file descriptor */ remote_rwlock_t lock; /*! protect offset modifications */ struct mapper_s * mapper; /*! associated file cache */ struct vfs_inode_s * inode; /*! local pointer on associated inode */ void * extend; /*! FS specific extension */ } vfs_file_t; /****************************************************************************************** * This structure define the informations associated to a file descriptor, * returned to user space by the stat() system call. *****************************************************************************************/ typedef struct vfs_stat_s { uint32_t dev; /*! ID of device containing file */ uint32_t ino; /*! inode number */ uint32_t mode; /*! protection */ uint32_t nlink; /*! number of hard links */ uint32_t uid; /*! user ID of owner */ uint32_t gid; /*! group ID of owner */ uint32_t rdev; /*! device ID (if special file) */ uint64_t size; /*! total size, in bytes */ uint32_t blksize; /*! blocksize for file system I/O */ uint32_t blocks; /*! number of 512B blocks allocated */ uint64_t atime; /*! time of last access */ uint64_t mtime; /*! time of last modification */ uint64_t ctime; /*! time of last status change */ } vfs_stat_t; /********************************************************************************************* * This structure defines the information associated to a directory entry, * returned to user space by the readdir() system call. ********************************************************************************************/ typedef struct vfs_dirent_s { uint32_t inum; /*! inode identifier */ uint32_t type; /*! inode type */ char name[CONFIG_VFS_MAX_NAME_LENGTH]; /*! dentry name */ } vfs_dirent_t; /*****************************************************************************************/ /******************** VFS global functions ***********************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function mount a given file system type for a given process TODO. *****************************************************************************************/ error_t vfs_mount_fs_root( struct device_s * device, uint32_t fs_type, struct process_s * process ); /*****************************************************************************************/ /******************* FS Context related functions ****************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function allocates an inode identifier from the local cluster inum allocator. * The inum respects a fixed format: * - the 16 MSB bits contain the cluster identifier : cxy * - the 16 LSB bits contains the local inode identifier : lid ****************************************************************************************** * @ ctx : local pointer on file system context. * @ inum : [ou] buffer for allocated inode identifier. * @ return 0 if success / return non-zero if error. *****************************************************************************************/ error_t vfs_ctx_inum_alloc( vfs_ctx_t * ctx, uint32_t * inum ); /****************************************************************************************** * This function release an inode identifier. ****************************************************************************************** * @ ctx : local pointer on file system context. * @ inum : released inode identifier. *****************************************************************************************/ void vfs_ctx_inum_release( vfs_ctx_t * ctx, uint32_t inum ); /*****************************************************************************************/ /********************* Inode related functions *******************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function allocates memory from local cluster for an inode descriptor and the * associated mapper. It initialise these descriptors from arguments values. * The parent dentry must have been previously created. * If the client thread is not running in the cluster containing this inode, * it must use the rpc_vfs_inode_create_client() function. ****************************************************************************************** * @ dentry_xp : extended pointer on associated dentry (in parent inode cluster). * @ fs_type : file system type. * @ inode_type : inode type. * @ attr : inode attributes. * @ rights : inode access rights. * @ uid : user owner ID. * @ gid : group owner ID. * @ inode_xp : [out] buffer for extended pointer on created inode. * # return 0 if success / return ENOMEM or EINVAL if error. *****************************************************************************************/ error_t vfs_inode_create( xptr_t dentry_xp, vfs_fs_type_t fs_type, vfs_inode_type_t inode_type, uint32_t attr, uint32_t rights, uid_t uid, gid_t gid, xptr_t * inode_xp ); /****************************************************************************************** * This function releases memory allocated to an inode descriptor. * It must be executed by a thread running in the cluster containing the inode, * and the inode refcount must be zero. * If the client thread is not running in the owner cluster, it must use the * rpc_vfs_inode_destroy_client() function. ****************************************************************************************** * @ inode : local pointer on inode descriptor. *****************************************************************************************/ void vfs_inode_destroy( vfs_inode_t * inode ); /****************************************************************************************** * This function atomically increment/decrement the inode refcount. * It can be called by any thread running in any cluster. *****************************************************************************************/ void vfs_inode_remote_up( xptr_t inode_xp ); void vfs_inode_remote_down( xptr_t inode_xp ); /****************************************************************************************** * This function returns the of a file/dir from a remote inode, * taking the remote_rwlock protecting in READ_MODE. ***************************************************************************************** * @ inode_xp : extended pointer on the remote inode. * @ return the current size. *****************************************************************************************/ uint32_t vfs_inode_get_size( xptr_t inode_xp ); /****************************************************************************************** * This function set the of a file/dir to a remote inode, * taking the remote_rwlock protecting in WRITE_MODE. ***************************************************************************************** * @ inode_xp : extended pointer on the remote inode. * @ size : value to be written. *****************************************************************************************/ void vfs_inode_set_size( xptr_t inode_xp, uint32_t size ); /****************************************************************************************** * This function takes the main lock of a remote inode. * This lock protect all inode fiels, including the children dentries. ***************************************************************************************** * @ inode_xp : extended pointer on the remote inode. *****************************************************************************************/ void vfs_inode_remote_lock( xptr_t inode_xp ); /****************************************************************************************** * This function releases the main lock of a remote inode. * This lock protect all inode fiels, including the children dentries. ***************************************************************************************** * @ inode_xp : extended pointer on the remote inode. *****************************************************************************************/ void vfs_inode_remote_unlock( xptr_t inode_xp ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_inode_hold( vfs_inode_t * inode, uint32_t gc ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_inode_trunc( vfs_inode_t * inode ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_inode_link( vfs_inode_t * inode, uint32_t igc ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_inode_unlink( vfs_inode_t * inode ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_inode_stat( vfs_inode_t * inode, uint32_t inum ); /****************************************************************************************** * This function TODO *****************************************************************************************/ error_t vfs_icache_del( vfs_inode_t * inode ); /****************************************************************************************** * This function TODO Pourquoi 2 arguments ? *****************************************************************************************/ error_t vfs_stat_inode( vfs_inode_t * inode, uint32_t inum ); /*****************************************************************************************/ /***************** Dentry related functions **********************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function allocates memory from local cluster for a dentry descriptor, * initialises it from arguments values, and returns the extended pointer on dentry. * The inode field is not initialized, because the inode does not exist yet. * If the client thread is not running in the target cluster for this inode, * it must use the rpc_dentry_create_client() function. ****************************************************************************************** * @ fs_type : file system type. * @ name : directory entry file/dir name. * @ parent : local pointer on parent inode. * @ dentry_xp : [out] buffer for extended pointer on created dentry. * @ return 0 if success / return ENOMEM or EINVAL if error. *****************************************************************************************/ error_t vfs_dentry_create( vfs_fs_type_t fs_type, char * name, vfs_inode_t * parent, xptr_t * dentry_xp ); /****************************************************************************************** * This function releases memory allocated to a dentry descriptor. * It must be executed by a thread running in the cluster containing the dentry, * and the dentry refcount must be zero. * If the client thread is not running in the owner cluster, it must use the * rpc_dentry_destroy_client() function. ****************************************************************************************** * @ dentry : local pointer on dentry descriptor. *****************************************************************************************/ void vfs_dentry_destroy( vfs_dentry_t * dentry ); /****************************************************************************************** * These functions atomically increment/decrement the dentry refcount. * It can be called by any thread running in any cluster. *****************************************************************************************/ void vfs_dentry_remote_up( xptr_t dentry_xp ); void vfs_dentry_remote_down( xptr_t dentry_xp ); /*****************************************************************************************/ /************************ File descriptor related functions ******************************/ /*****************************************************************************************/ /****************************************************************************************** * This function allocates memory and initializes a new local file descriptor. * It must be executed in the cluster containing the inode. * If the client thread is not running in the owner cluster, it must use the * rpc_vfs_file_create_client() function. ****************************************************************************************** * @ inode : local pointer on associated inode. * @ attr : file descriptor attributes. * @ file_xp : [out] buffer for extended pointer on created file descriptor. * @ return 0 if success / return ENOMEM if error. *****************************************************************************************/ error_t vfs_file_create( vfs_inode_t * inode, uint32_t attr, xptr_t * file_xp ); /****************************************************************************************** * This function releases memory allocated to a local file descriptor. * It must be executed by a thread running in the cluster containing the inode, * and the file refcount must be zero. * If the client thread is not running in the owner cluster, it must use the * rpc_vfs_file_destroy_client() function. ****************************************************************************************** * @ file : local pointer on file descriptor. *****************************************************************************************/ void vfs_file_destroy( vfs_file_t * file ); /****************************************************************************************** * These functions increment (resp. decrement) the count field in a remote file * descriptor, using a remote_atomic access. *****************************************************************************************/ void vfs_file_count_up ( xptr_t file_xp ); void vfs_file_count_down( xptr_t file_xp ); /*****************************************************************************************/ /******************* Inode-Tree related functions ****************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function returns in a kernel buffer allocated by the caller function, * the pathname of a file/dir identified by an extended pointer on the inode. * It traverse the Inode Tree from the target node to the root. * It can be called by any thread running in any cluster. ****************************************************************************************** * @ inode_xp : pointer on inode descriptor. * @ buffer : kernel buffer for pathname (must be allocated by caller). * @ size : max number of characters in buffer. * @ return 0 if success / return EINVAL if buffer too small. *****************************************************************************************/ error_t vfs_get_path( xptr_t inode_xp, char * buffer, uint32_t max_size ); /****************************************************************************************** * This function takes a pathname (absolute or relative to cwd) and returns an extended * pointer on the associated inode. * - If a given name in the path is not found in the inode tree, it try to load the missing * dentry/inode couple, from informations found in the parent directory. * - If this directory entry does not exist on device, it returns an error. * - If the the file identified by the pathname does not exist on device but the * flag CREATE is set, the inode is created. * - If the the file identified by the pathname exist on device but both flags EXCL * and CREATE are set, an error is returned. ****************************************************************************************** * @ cwd_xp : extended pointer on current directory (for relative path). * @ pathname : path in kernel space (can be relative or absolute). * @ lookup_mode : flags defining the working mode (defined above in this file). * @ inode_xp : [out] buffer for extended pointer on inode. * @ return 0 if success / ENOENT if inode not found , EACCES if permissopn denied, * EAGAIN if a new complete lookup must be made *****************************************************************************************/ error_t vfs_lookup( xptr_t cwd_xp, char * pathname, uint32_t lookup_mode, xptr_t * inode_xp ); /****************************************************************************************** * This function creates a new couple dentry/inode, and insert it in the Inode-Tree. * It can be executed by any thread running in any cluster, as this function * uses the rpc_dentry_create_client() and rpc_inode_create client() if required. * - The dentry is created in the cluster containing the existing inode. * - the child inode and its associated mapper are created in a randomly selected cluster. * - The new dentry name is defined by the argument. * - The new inode and the parent inode can have different FS types. ****************************************************************************************** * @ inode_type : new inode type * @ fs_type : new inode FS type. * @ parent_xp : extended pointer on parent inode. * @ name : new directory entry name. * @ child_xp : [out] buffer for extended pointer on child inode. * @ return 0 if success / ENOENT if entry not found in parent directory *****************************************************************************************/ error_t vfs_add_child_in_parent( vfs_inode_type_t inode_type, vfs_fs_type_t fs_type, xptr_t parent_xp, char * name, xptr_t * child_xp ); /****************************************************************************************** * This function removes a couple dentry/inode from the Inode-Tree, and remove it from * the external device. * TODO ****************************************************************************************** * @ child_xp : extended pointer on removed inode. *****************************************************************************************/ error_t vfs_remove_child_from_parent( xptr_t child_xp ); /*****************************************************************************************/ /****************** File access API ******************************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function allocates a vfs_file_t structure in the cluster containing the inode * associated to the file identified by & . * It initializes it, register it in the reference process fd_array, and returns both * the extended pointer on the remote file descriptor, and the index in the fd_array. * The pathname can be relative to current directory or absolute. * If the inode does not exist in the inode cache, it try to find the file on the mounted * device, and creates an inode on a pseudo randomly selected cluster if found. * It the requested file does not exist on device, it creates a new inode if the * O_CREAT flag is set and return an error otherwise. ****************************************************************************************** * @ cwd_xp : extended pointer on current working directory file descriptor. * @ path : file pathname (absolute or relative to current directory). * @ flags : defined above * @ mode : access rights (as defined by chmod) * @ file_xp : [out] buffer for extended pointer on created remote file descriptor. * @ file_id : [out] buffer for created file descriptor index in reference fd_array. * @ return 0 if success / return non-zero if error. *****************************************************************************************/ error_t vfs_open( xptr_t cwd_xp, char * path, uint32_t flags, uint32_t mode, xptr_t * file_xp, uint32_t * file_id ); /****************************************************************************************** * This function moves bytes between the file identified by the open file descriptor * and a local kernel , taken into account the offset in . * The transfer direction is defined by the argument. ****************************************************************************************** * @ to_buffer : mapper -> buffer if true / buffer->mapper if false. * @ file_xp : extended pointer on the remote file descriptor. * @ buffer : local pointer on local kernel buffer. * @ size : requested number of bytes from offset. * @ returns number of bytes actually transfered / -1 if error. *****************************************************************************************/ error_t vfs_move( bool_t to_buffer, xptr_t file_xp, void * buffer, uint32_t size ); /****************************************************************************************** * This function set a new value in the offset of the open file descriptor . * This value depends on the argument: * - if VFS_SEEK_SET, new value is * - if VFS_SEEK_CUR, new value is current_offset + * - if VFS_SEEK_END, new value is file_size + ****************************************************************************************** * @ file_xp : extended pointer on the remote open file descriptor. * @ offset : local pointer on source kernel buffer. * @ whence : VFS_SEEK_SET / VFS_SEEK_CUR / VFS_SEEK_END. * @ new_offset : [out] buffer for new offset value. * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_lseek( xptr_t file_xp, uint32_t offset, uint32_t whence, uint32_t * new_offset ); /****************************************************************************************** * This function close an open file descriptor: * 1) All entries in fd_array copies are directly cancelled by the calling thread, * using remote accesses. * 2) The memory allocated to file descriptor in cluster containing the inode is released. * It requires a RPC if cluster containing the file descriptor is remote. ****************************************************************************************** * @ file_xp : extended pointer on the file descriptor. * @ file_id : file descriptor index in fd_array. * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_close( xptr_t file_xp, uint32_t file_id ); /****************************************************************************************** * This function remove from the file system a directory entry identified by the * & arguments. ****************************************************************************************** * @ cwd_xp : extended pointer on the current working directory file descriptor. * @ path : pathname (absolute or relative to current directory). * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_unlink( xptr_t cwd_xp, char * path ); /****************************************************************************************** * This function returns, in the structure pointed by the kernel pointer, * various informations on the file descriptor identified by the argument. * TODO not implemented yet... ****************************************************************************************** * @ file_xp : extended pointer on the file descriptor of the searched directory . * @ k_dirent : local pointer on the dirent_t structure in kernel space. * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_stat( xptr_t file_xp, vfs_stat_t * k_stat ); /****************************************************************************************** * This function returns, in the structure pointed by the kernel pointer, * various infos on the directory entry currently pointed by the file descriptor. * TODO not implemented yet... ****************************************************************************************** * @ file_xp : extended pointer on the file descriptor of the searched directory . * @ k_dirent : local pointer on the dirent_t structure in kernel space. * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_readdir( xptr_t file_xp, vfs_dirent_t * k_dirent ); /****************************************************************************************** * This function creates a new inode and associated dentry for the directory defined * by the & arguments. * TODO not implemented yet... ****************************************************************************************** * @ cwd_xp : extended pointer on the current working directory file descriptor. * @ path : pathname (absolute or relative to current directory). * @ mode : access rights (as defined by chmod) * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_mkdir( xptr_t cwd_xp, char * path, uint32_t mode ); /****************************************************************************************** * This function remove a directory identified by the arguments * from the file system. * TODO not implemented yet... ****************************************************************************************** * @ cwd_xp : extended pointer on the current working directory file descriptor. * @ path : pathname (absolute or relative to current directory). * @ returns 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_rmdir( xptr_t cwd_xp, char * path ); /****************************************************************************************** * This function makes the directory identified by arguments to become * the working directory for the calling process. ****************************************************************************************** * @ cwd_xp : extended pointer on current directory file descriptor (relative path). * @ path : file pathname (absolute or relative to current directory). * return 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_chdir( xptr_t cwd_xp, char * path ); /****************************************************************************************** * This function change the access rigths for the file identified by the * arguments. The new access rights are defined by the argument value. ****************************************************************************************** * @ cwd_xp : extended pointer on current directory file descriptor (relative path). * @ path : file pathname (absolute or relative to current directory). * @ mode : access rights new value. * return 0 if success / -1 if error. *****************************************************************************************/ error_t vfs_chmod( xptr_t cwd_xp, char * path, uint32_t mode ); /****************************************************************************************** * This function creates a named FIFO file. * TODO not implemented yet ****************************************************************************************** * @ path : FIFO pathname (absolute or relative to current directory). * @ cwd_xp : extended pointer on the current working directory file descriptor. * @ mode : access rights new value. *****************************************************************************************/ error_t vfs_mkfifo( xptr_t cwd_xp, char * path, uint32_t mode ); /*****************************************************************************************/ /****************** Mapper access API ****************************************************/ /*****************************************************************************************/ /****************************************************************************************** * This function makes an I/O operation to move one page from VFS to a given mapper, * in case of MISS on the mapper cache. * Depending on the file system type, it calls the proper, FS specific function. * It must be executed by a thread running in the cluster containing the mapper. * The mapper pointer is obtained from the page descriptor. * It takes the mapper lock before launching the IO operation. ****************************************************************************************** * @ page : local pointer on the page descriptor. * @ returns 0 if success / return EINVAL if it cannot access the external device. *****************************************************************************************/ error_t vfs_move_page_to_mapper( struct page_s * page ); /****************************************************************************************** * This function makes an I/0 operation to move one page from a given mapper to VFS, * when a dirty page in the mapper cache must be updated in the File System. * Depending on the file system type, it calls the proper, FS specific function. * It must be executed by a thread running in the cluster containing the mapper. * The mapper pointer is obtained from the page descriptor. * It takes the mapper lock before launching the IO operation. * It does nothing if the page is not dirty. If the page is dirty, it clear the page * dirty bit, and remove the page from the PPM dirty list. ****************************************************************************************** * @ page : local pointer on the page descriptor. * @ returns 0 if success / return EINVAL if it cannot access the external device. *****************************************************************************************/ error_t vfs_move_page_from_mapper( struct page_s * page ); /////////////////////////////////////////////////////////////////////////////////////////// // These typedef define the FS specific operations that must be implemented by any // specific file system to be supported by the ALMOS_MKH VFS. // These typedef are not actually used, and are only defined for documentation /////////////////////////////////////////////////////////////////////////////////////////// typedef error_t (fs_init_t) ( xptr_t vfs_root_xp ); typedef error_t (fs_inode_extend_t) ( struct vfs_inode_s * inode, void * extend ); typedef void (fs_inode_release_t) ( struct vfs_inode_s * inode ); typedef error_t (fs_write_page_t) ( struct page_s * page ); typedef error_t (fs_read_page_t) ( struct page_s * page ); /* deprecated [AG] typedef error_t (lookup_inode_t) ( vfs_inode_t * parent , vfs_dentry_t * dentry ); typedef error_t (write_inode_t) ( vfs_inode_t * inode ); typedef error_t (release_inode_t) ( vfs_inode_t * inode ); typedef error_t (unlink_inode_t) ( vfs_inode_t * parent, vfs_dentry_t * dentry, uint32_t flags ); typedef error_t (stat_inode_t) ( vfs_inode_t * inode ); typedef error_t (trunc_inode_t) ( vfs_inode_t * inode ); typedef error_t (delete_inode_t) ( vfs_inode_t * inode ); typedef struct vfs_inode_op_s { init_inode_t * init; create_inode_t * create; lookup_inode_t * lookup; write_inode_t * write; release_inode_t * release; unlink_inode_t * unlink; delete_inode_t * delete; stat_inode_t * stat; trunc_inode_t * trunc; // change the size of a file } vfs_inode_op_t; ****************************************************************************************** * These typedef define the set of FS specific operations on a VFS DENTRY descriptor. * They must be implemented by any specific file system to be supported by ALMOS_MKH. * This code is not actually used, and is only defined for documentation ****************************************************************************************** typedef error_t (vfs_compare_dentry_t) ( char * first , char * second ); typedef struct vfs_dentry_op_s { vfs_compare_dentry_t * compare; } vfs_dentry_op_t; ****************************************************************************************** * These typedef define the set of FS specific operations on FILE descriptors * They must be implemented by any specific file system to be supported by ALMOS_MKH. * This code is not actually used, and is only defined for documentation ****************************************************************************************** typedef error_t (open_file_t ) ( vfs_file_t * file, void * extend ); typedef error_t (read_file_t ) ( vfs_file_t * file, char * buffer, uint32_t count ); typedef error_t (write_file_t ) ( vfs_file_t * file, char * buffer, uint32_t count ); typedef error_t (lseek_file_t ) ( vfs_file_t * file ); typedef error_t (close_file_t ) ( vfs_file_t * file ); typedef error_t (release_file_t) ( vfs_file_t * file ); typedef error_t (read_dir_t ) ( vfs_file_t * file ); typedef error_t (mmap_file_t ) ( vfs_file_t * file , struct vseg_s * vseg ); typedef error_t (munmap_file_t ) ( vfs_file_t * file, struct vseg_s * vseg ); typedef struct vfs_file_op_s { open_file_t * open; read_file_t * read; write_file_t * write; lseek_file_t * lseek; read_dir_t * readdir; close_file_t * close; release_file_t * release; mmap_file_t * mmap; munmap_file_t * munmap; } vfs_file_op_t; */ #endif /* _VFS_H_ */