/* * user_dir.h - DIR related operations definition. * * Authors Alain Greiner (2016,2017,2018,2019) * * 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 _REMOTE_DIR_H_ #define _REMOTE_DIR_H_ #include #include #include /*** Forward declarations ***/ struct vfs_inode_s; /***************************************************************************************** * This file defines the operations on a directory open by an user process * * - An user process open a directory by calling the "opendir()" syscall. * The user_dir_create() function allocates physical memory to create in the cluster * containing the target inode one or several physical pages to implement an array * of "dirent", mapped in the user process space as an ANON vseg. It allocates also * an "user_dir_t" descriptor structure defined below, registered in the xlist rooted * in the reference user process descriptor. * - This "user_dir_t" structure contains the total number of "entries", the "current" * pointer used by the readdir() syscall, and an "ident" field, that is actually * the DIR user pointer on the "dirent" array in user space. * - all these structures are destroyed by the closedir() syscall, that release to the * kernel all allocated memory. * * WARNING: ALMOS-MKH makes explicitely the assumption that sizeof(dirent) == 64 ****************************************************************************************/ /***************************************************************************************** * This structure defines the user_dir_t decriptor, that is the kernel implementation * of a directory open by an user process. ****************************************************************************************/ typedef struct user_dir_s { intptr_t ident; /*! pointer on dirent array in user space */ xlist_entry_t list; /*! member of list of open dir in same process */ uint32_t entries; /*! actual number of dirent in dirent array */ uint32_t current; /*! current dirent index in dirent array */ } user_dir_t; /***************************************************************************************** * This function returns an extended pointer on the user_dir_t structure, * identified by the DIR pointer in the user process virtual space. * It makes an associative search, scanning the xlist of user_dir_t rooted * in the reference process descriptor. ***************************************************************************************** * @ ident : [in] DIR virtual address, used as identifier. * @ returns extended pointer on user_dir_t if success / returns XPTR_NULL if not found. ****************************************************************************************/ xptr_t user_dir_from_ident( intptr_t ident ); /***************************************************************************************** * This function allocates memory and initializes a user_dir_t structure in the cluster * containing the directory inode identified by the argument and map the * user accessible dirent array in the reference user process VSL, identified by the * argument. * It must be executed by a thread running in the cluster containing the target inode. * Use the RPC_USER_DIR_CREATE when the client thread is remote. * It makes the following actions: * - the allocation of one user_dir_t descriptor in the directory inode cluster. * - the allocation of one or several physical pages in reference cluster to store * all directory entries in an array of 64 bytes dirent structures, * - the initialisation of this array from informations found in the directory mapper. * - the creation of an ANON vseg containing this dirent array in reference process VMM, * and the mapping of the relevant physical pages in this vseg. * - the registration of the created user_dir_t structure in the xlist rooted * in the reference process, * It returns a local pointer on the created user_dir_t structure. ***************************************************************************************** * @ inode : [in] local pointer on the directory inode. * @ ref_xp : [in] extended pointer on the reference user process descriptor. * @ return local pointer on user_dir_t if success / return XPTR_NULL if failure. ****************************************************************************************/ user_dir_t * user_dir_create( struct vfs_inode_s * inode, xptr_t ref_xp ); /***************************************************************************************** * This function removes a user_dir_t structure from the xlist of user_dir_t * structures rooted in the reference process descriptor, release all memory * allocated for the user_dir_t struct in the directory inode cluster, including * the dirent array, and delete all ANON vseg copies in all process VMM copies, * using parallel RPCs. * It must be executed by a thread running in the cluster containing the target inode. * Use the RPC_USER_DIR_DESTROY when the client thread is remote. ***************************************************************************************** * @ dir : [in] local pointer on user_dir_t structure. * @ ref_xp : [in] extended pointer on the reference user process descriptor. ****************************************************************************************/ void user_dir_destroy( struct user_dir_s * dir, xptr_t ref_xp ); #endif