/* * fatfs.c - FATFS file system API implementation. * * Author 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 */ #include #include #include #include #include #include #include #include #include #include #include #include ////////////////////////////////////////////////////////////////////////////////////////// // Extern variables ////////////////////////////////////////////////////////////////////////////////////////// extern vfs_ctx_t fs_context[FS_TYPES_NR]; // allocated in vfs.c file extern remote_barrier_t global_barrier; // allocated in kernel_init.c ////////////////////////////////////////////////////////////////////////////////////////// // FATFS private and static functions ////////////////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////////////////// // These functions return the "offset" and "length" values of an // [offset,length] constant defined in the fatfs.h file. ////////////////////////////////////////////////////////////////////////////////////////// static inline int get_length( int offset , int length ) { return length; } static inline int get_offset( int offset , int length ) { return offset; } ////////////////////////////////////////////////////////////////////////////////////////// // This function returns the LBA of the first sector of a FAT cluster. // This function can be called by any thread running in any cluster. ////////////////////////////////////////////////////////////////////////////////////////// // @ ctx : pointer on FATFS context. // @ cluster : cluster index in FATFS. // @ return the lba value. ////////////////////////////////////////////////////////////////////////////////////////// static inline uint32_t fatfs_lba_from_cluster( fatfs_ctx_t * ctx, uint32_t cluster ) { return (ctx->cluster_begin_lba + ((cluster - 2) << 3)); } ////////////////////////////////////////////////////////////////////////////////////////// // This function return an integer record value (one, two, or four bytes) // from a memory buffer, taking into account endianness. ////////////////////////////////////////////////////////////////////////////////////////// // @ offset : first byte of record in buffer. // @ size : record length in bytes (1/2/4). // @ buffer : pointer on buffer base. // @ little endian : the most significant byte has the highest address when true. // @ return the integer value in a 32 bits word. ////////////////////////////////////////////////////////////////////////////////////////// static uint32_t fatfs_get_record( uint32_t offset, uint32_t size, uint8_t * buffer, uint32_t little_endian ) { uint32_t n; uint32_t res = 0; if ( little_endian) { for( n = size ; n > 0 ; n-- ) res = (res<<8) | buffer[offset+n-1]; } else { for( n = 0 ; n < size ; n++ ) res = (res<<8) | buffer[offset+n]; } return res; } // end fatfs_get_record() ////////////////////////////////////////////////////////////////////////////////////////// // This static function retun in the buffer a short name stored in // a SFN FATFS directory entry. /////////////////////////i//////////////////////////////////////////////////////////////// // @ buffer : pointer on buffer containing the directory entry. // @ name : [out] buffer allocated by the caller. ////////////////////////////////////////////////////////////////////////////////////////// static void fatfs_get_name_from_short( uint8_t * buffer, char * name ) { uint32_t i; uint32_t j = 0; // get name for ( i = 0; i < 8 && buffer[i] != ' '; i++ ) { name[j] = to_lower( buffer[i] ); j++; } // get extension for ( i = 8; i < 8 + 3 && buffer[i] != ' '; i++ ) { // we entered the loop so there is an extension. add the dot if ( i == 8 ) { name[j] = '.'; j++; } name[j] = to_lower( buffer[i] ); j++; } name[j] = '\0'; } ////////////////////////////////////////////////////////////////////////////////////////// // This static function retun in the buffer a partial name stored in // a LFN FATFS directory entry. /////////////////////////i//////////////////////////////////////////////////////////////// // @ buffer : pointer on buffer containing the directory entry. // @ name : [out] buffer allocated by the caller. ////////////////////////////////////////////////////////////////////////////////////////// static void fatfs_get_name_from_long( uint8_t * buffer, char * name ) { uint32_t name_offset = 0; uint32_t buffer_offset = get_length(LDIR_ORD); uint32_t l_name_1 = get_length(LDIR_NAME_1); uint32_t l_name_2 = get_length(LDIR_NAME_2); uint32_t l_name_3 = get_length(LDIR_NAME_3); uint32_t l_attr = get_length(LDIR_ATTR); uint32_t l_type = get_length(LDIR_TYPE); uint32_t l_chksum = get_length(LDIR_CHKSUM); uint32_t l_rsvd = get_length(LDIR_RSVD); uint32_t j = 0; uint32_t eof = 0; while ( (buffer_offset != DIR_ENTRY_SIZE) && (!eof) ) { while (j != l_name_1 && !eof ) { if ( (buffer[buffer_offset] == 0x00) || (buffer[buffer_offset] == 0xFF) ) { eof = 1; continue; } name[name_offset] = buffer[buffer_offset]; buffer_offset += 2; j += 2; name_offset++; } buffer_offset += (l_attr + l_type + l_chksum); j = 0; while (j != l_name_2 && !eof ) { if ( (buffer[buffer_offset] == 0x00) || (buffer[buffer_offset] == 0xFF) ) { eof = 1; continue; } name[name_offset] = buffer[buffer_offset]; buffer_offset += 2; j += 2; name_offset++; } buffer_offset += l_rsvd; j = 0; while (j != l_name_3 && !eof ) { if ( (buffer[buffer_offset] == 0x00) || (buffer[buffer_offset] == 0xFF) ) { eof = 1; continue; } name[name_offset] = buffer[buffer_offset]; buffer_offset += 2; j += 2; name_offset++; } } name[name_offset] = 0; } // end get_name_from_long() ////////////////////////////////////////////////////////////////////////////////////////// // This function returns the FATFS cluster index of a page identified by its page // index in the file, using the FAT mapper. It scans the FAT mapper, starting from the // FATFS cluster index allocated to the first page of the file, until it reaches the // searched page. The FAT mapper is automatically updated in case of miss. // This function can be called by any thread running in any cluster, as it uses the // RPC_FATFS_GET_CLUSTER to access the remote FAT mapper if required. // We use a RPC to scan the FAT because the RPC_FIFO will avoid contention // in the cluster containing the FAT mapper, and the RPC latency is not critical // compared to the device access latency. ////////////////////////////////////////////////////////////////////////////////////////// // @ ctx : pointer on local FATFS context. // @ first_cluster : first cluster allocated to a file in FATFS. // @ page_index : index of searched page in file (one page occupies one cluster). // @ cluster_index : [out] pointer on buffer for FATFS cluster index. // @ return 0 if success / return EIO if a FAT cluster miss cannot be solved. ////////////////////////////////////////////////////////////////////////////////////////// static error_t fatfs_cluster_from_index( fatfs_ctx_t * ctx, uint32_t first_cluster, uint32_t page_index, uint32_t * cluster_index ) { uint32_t searched_cluster; // searched FATFS cluster index error_t error; // get extended pointer on FAT mapper xptr_t fat_mapper_xp = ctx->fat_mapper_xp; // get cluster cxy and local pointer on FAT mapper cxy_t fat_mapper_cxy = GET_CXY( fat_mapper_xp ); mapper_t * fat_mapper_ptr = (mapper_t *)GET_PTR( fat_mapper_xp ); if( fat_mapper_cxy == local_cxy ) // FAT mapper is local { error = fatfs_get_cluster( fat_mapper_ptr, first_cluster, page_index, &searched_cluster ); } else // FAT mapper is remote { rpc_fatfs_get_cluster_client( fat_mapper_cxy, fat_mapper_ptr, first_cluster, page_index, &searched_cluster, &error ); } if( error ) { printk("\n[ERROR] in %s : cannot access FAT\n", __FUNCTION__ ); return error; } // return success *cluster_index = searched_cluster; return 0; } // end fatfs_cluster_from_index() ////////////////////////////////////////////////////////////////////////////////////////// // FATFS specific but public functions (used by RPC_FATFS_GET_CLUSTER) ////////////////////////////////////////////////////////////////////////////////////////// ///////////////////////////////////////////// error_t fatfs_get_cluster( mapper_t * mapper, uint32_t first_cluster, uint32_t searched_page, uint32_t * cluster ) { page_t * current_page_desc; // pointer on current page descriptor uint32_t * current_page_buffer; // pointer on current page (array of uint32_t) uint32_t current_page_index; // index of current page in mapper uint32_t current_page_offset; // offset of slot in current page uint32_t page_count_in_file; // index of page in file (index in linked list) uint32_t current_cluster; // content of current FAT slot // compute number of FAT slots per PPM page uint32_t slots_per_page = CONFIG_PPM_PAGE_SIZE >> 2; // initialize loop variable current_page_index = first_cluster / slots_per_page; current_page_offset = first_cluster % slots_per_page; page_count_in_file = 0; // scan FAT (i.e. traverse FAT linked list) while( page_count_in_file <= searched_page ) { // get pointer on current page descriptor current_page_desc = mapper_get_page( mapper , current_page_index ); if( current_page_desc == NULL ) return EIO; // get pointer on buffer for current page current_page_buffer = (uint32_t *)ppm_page2vaddr( current_page_desc ); // get FAT slot content current_cluster = current_page_buffer[current_page_offset]; // update loop variables current_page_index = current_cluster / slots_per_page; current_page_offset = current_cluster % slots_per_page; page_count_in_file++; } // return success *cluster = current_cluster; return 0; } // end fatfs_get_cluster() /////////////////////////////////////////////////////////////////////////////////////// // Generic API : the following functions are called by the kernel (VFS) // and must be defined by all supported file systems. /////////////////////////////////////////////////////////////////////////////////////// /////////////////////////////// fatfs_ctx_t * fatfs_ctx_alloc() { kmem_req_t req; req.type = KMEM_FATFS_CTX; req.size = sizeof(fatfs_ctx_t); req.flags = AF_KERNEL | AF_ZERO; return (fatfs_ctx_t *)kmem_alloc( &req ); } ////////////////////////////////////////////// void fatfs_ctx_init( fatfs_ctx_t * fatfs_ctx ) { error_t error; kmem_req_t req; uint8_t * buffer; fatfs_dmsg("\n[INFO] %s : enters at cycle %d\n", __FUNCTION__ , hal_get_cycles() ); // allocate memory for FATFS context req.type = KMEM_FATFS_CTX; req.size = sizeof(fatfs_ctx_t); req.flags = AF_KERNEL | AF_ZERO; fatfs_ctx = (fatfs_ctx_t *)kmem_alloc( &req ); nolock_assert( (fatfs_ctx != NULL) , __FUNCTION__ , "cannot allocate memory for FATFS context\n" ); // allocate a 512 bytes buffer to store the boot record req.type = KMEM_512_BYTES; req.flags = AF_KERNEL | AF_ZERO; buffer = (uint8_t *)kmem_alloc( &req ); nolock_assert( (buffer != NULL) , __FUNCTION__ , "cannot allocate memory for 512 bytes buffer\n" ); // load the boot record from device // using a synchronous access to IOC device error = dev_ioc_sync_read( buffer , 0 , 1 ); nolock_assert( (error == 0) , __FUNCTION__ , "cannot access boot record\n" ); #if CONFIG_FATFS_DEBUG uint32_t line; uint32_t byte = 0; printk("\n*** boot record at cycle %d ***\n", hal_get_cycles() ); for ( line = 0 ; line < 32 ; line++ ) { printk(" %X | %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x %x |\n", byte, buffer[byte+ 0],buffer[byte+ 1],buffer[byte+ 2],buffer[byte+ 3], buffer[byte+ 4],buffer[byte+ 5],buffer[byte+ 6],buffer[byte+ 7], buffer[byte+ 8],buffer[byte+ 9],buffer[byte+10],buffer[byte+11], buffer[byte+12],buffer[byte+13],buffer[byte+14],buffer[byte+15] ); byte += 16; } #endif // check sector size from boot record uint32_t sector_size = fatfs_get_record( BPB_BYTSPERSEC , buffer , 1 ); nolock_assert( (sector_size == 512) , __FUNCTION__ , "sector size must be 512 bytes\n" ); // check cluster size from boot record uint32_t nb_sectors = fatfs_get_record( BPB_SECPERCLUS , buffer , 1 ); nolock_assert( (nb_sectors == 8) , __FUNCTION__ , "cluster size must be 8 sectors\n" ); // check number of FAT copies from boot record uint32_t nb_fats = fatfs_get_record( BPB_NUMFATS , buffer , 1 ); nolock_assert( (nb_fats == 1) , __FUNCTION__ , "number of FAT copies must be 1\n" ); // get & check number of sectors in FAT from boot record uint32_t fat_sectors = fatfs_get_record( BPB_FAT32_FATSZ32 , buffer , 1 ); nolock_assert( ((fat_sectors & 0xF) == 0) , __FUNCTION__ , "FAT not multiple of 16 sectors\n"); // get and check root cluster from boot record uint32_t root_cluster = fatfs_get_record( BPB_FAT32_ROOTCLUS , buffer , 1 ); nolock_assert( (root_cluster == 2) , __FUNCTION__ , "root cluster index must be 2\n"); // get FAT lba from boot record uint32_t fat_lba = fatfs_get_record( BPB_RSVDSECCNT , buffer , 1 ); // release the 512 bytes buffer req.type = KMEM_512_BYTES; req.ptr = buffer; kmem_free( &req ); // allocate a mapper for the FAT itself mapper_t * fat_mapper = mapper_create(); assert( (fat_mapper != NULL) , __FUNCTION__ , "no memory for FAT mapper" ); // initialize the FATFS context fatfs_ctx->fat_begin_lba = fat_lba; fatfs_ctx->fat_sectors_count = fat_sectors; fatfs_ctx->bytes_per_sector = sector_size; fatfs_ctx->sectors_per_cluster = nb_sectors; fatfs_ctx->cluster_begin_lba = fat_lba + fat_sectors; fatfs_ctx->root_dir_cluster = 2; fatfs_ctx->last_allocated_sector = 0; // TODO ??? fatfs_ctx->last_allocated_index = 0; // TODO ??? fatfs_ctx->fat_mapper_xp = XPTR( local_cxy , fat_mapper ); fatfs_dmsg("\n*** FAT context ***\n" "- fat_sectors = %d\n" "- sector size = %d\n" "- cluster size = %d\n" "- fat_first_lba = %d\n" "- data_first_lba = %d\n" "- mapper = %l\n", fatfs_ctx->fat_sectors_count, fatfs_ctx->bytes_per_sector, fatfs_ctx->bytes_per_cluster, fatfs_ctx->fat_begin_lba, fatfs_ctx->cluster_begin_lba, fatfs_ctx->fat_mapper_xp ); } // end fatfs_ctx_init() ///////////////////////////////////////////////// void fatfs_ctx_destroy( fatfs_ctx_t * fatfs_ctx ) { kmem_req_t req; req.type = KMEM_FATFS_CTX; req.ptr = fatfs_ctx; kmem_free( &req ); } /////////////////////////////////////// error_t fatfs_move_page( page_t * page, bool_t to_mapper ) { // get memory buffer base address uint8_t * buffer = (uint8_t *)ppm_page2vaddr( page ); // get pointer on source mapper and page index from page descriptor mapper_t * mapper = page->mapper; uint32_t page_index = page->index; // get VFS inode pointer from mapper vfs_inode_t * vfs_inode = mapper->inode; // get first cluster index from VFS inode uint32_t first_cluster = (uint32_t)(intptr_t)vfs_inode->extend; // get FATFS context pointer from VFS context fatfs_ctx_t * fatfs_ctx = (fatfs_ctx_t *)fs_context[FS_TYPE_FATFS].extend; // get number of sectors uint32_t count = fatfs_ctx->sectors_per_cluster; // compute FATFS_cluster index for the accessed page uint32_t cluster = 0; error_t error = fatfs_cluster_from_index( fatfs_ctx, first_cluster, page_index, &cluster ); if( error ) return EIO; // get lba from cluster uint32_t lba = fatfs_lba_from_cluster( fatfs_ctx , cluster ); // access device if( to_mapper ) error = dev_ioc_read ( buffer , lba , count ); else error = dev_ioc_write( buffer , lba , count ); if( error ) { printk("\n[ERROR] in %s : cannot access IOC device\n", __FUNCTION__ ); return error; } // successful access return 0; } ///////////////////////////////////////////////////////////////// error_t fatfs_inode_load( vfs_inode_t * parent_inode, char * name, xptr_t child_inode_xp ) { // Two embedded loops: // - scan the parent mapper pages // - scan the directory entries in each 4 Kbytes page fatfs_dmsg("\n[INFO] %s : enter for child <%s> in parent inode %l\n", __FUNCTION__ , name , child_inode_xp ); mapper_t * mapper = parent_inode->mapper; assert( (mapper != NULL) , __FUNCTION__ , "parent mapper undefined\n"); char cname[CONFIG_VFS_MAX_NAME_LENGTH]; // name extracter from each directory entry char lfn1[16]; // buffer for one partial cname char lfn2[16]; // buffer for one partial cname char lfn3[16]; // buffer for one partial cname page_t * page; // pointer on current page descriptor uint8_t * base; // pointer on current page base uint32_t offset = 0; // byte offset in page uint32_t index = 0; // page index in mapper uint32_t attr; // directory entry ATTR field uint32_t ord; // directory entry ORD field uint32_t seq; // sequence index uint32_t lfn = 0; // LFN entries number uint32_t size = 0; // searched file/dir size (bytes) uint32_t cluster = 0; // searched file/dir cluster index uint32_t is_dir = 0; // searched file/dir type uint32_t dentry; // directory entry index int32_t found = 0; // not found (0) / name found (1) / end of dir (-1) // scan the parent directory mapper while ( found == 0 ) { // get one page page = mapper_get_page( mapper , index ); assert( (page != NULL) , __FUNCTION__ , "bad parent mapper\n"); // get page base base = ppm_page2vaddr( page ); // scan this page until end of directory, end of page, or name found while( (offset < 4096) && (found == 0) ) { attr = fatfs_get_record( DIR_ATTR , base + offset , 0 ); ord = fatfs_get_record( LDIR_ORD , base + offset , 0 ); if (ord == NO_MORE_ENTRY) // no more entry => break { found = -1; } else if ( ord == FREE_ENTRY ) // free entry => skip { offset = offset + 32; } else if ( attr == ATTR_LONG_NAME_MASK ) // LFN entry => get partial cname { seq = ord & 0x3; lfn = (seq > lfn) ? seq : lfn; if ( seq == 1 ) fatfs_get_name_from_long( base + offset, lfn1 ); else if ( seq == 2 ) fatfs_get_name_from_long( base + offset, lfn2 ); else if ( seq == 3 ) fatfs_get_name_from_long( base + offset, lfn3 ); offset = offset + 32; } else // NORMAL entry { // build the extracted name if ( lfn == 0 ) { fatfs_get_name_from_short( base + offset , cname ); } else if ( lfn == 1 ) { strcpy( cname , lfn1 ); } else if ( lfn == 2 ) { strcpy( cname , lfn1 ); strcpy( cname + 13 , lfn2 ); } else if ( lfn == 3 ) { strcpy( cname , lfn1 ); strcpy( cname + 13 , lfn2 ); strcpy( cname + 26 , lfn3 ); } // get dentry arguments if extracted cname == searched name if ( strcmp( name , cname ) == 0 ) { cluster = (fatfs_get_record( DIR_FST_CLUS_HI , base + offset , 1 ) << 16) | (fatfs_get_record( DIR_FST_CLUS_LO , base + offset , 1 ) ) ; dentry = ((index<<12) + offset)>>5; is_dir = ((attr & ATTR_DIRECTORY) == ATTR_DIRECTORY); size = fatfs_get_record( DIR_FILE_SIZE , base + offset , 1 ); found = 1; } offset = offset + 32; lfn = 0; } } // end loop on directory entries index++; offset = 0; } // end loop on pages // analyse the result of scan if ( found == -1 ) // found end of directory => failure { fatfs_dmsg("\n[INFO] %s : child <%s> not found in parent inode %l\n", __FUNCTION__ , name , parent_inode_xp ); return ENOENT; } else // found searched child name { fatfs_dmsg("\n[INFO] %s : child <%s> found in parent inode %l\n", __FUNCTION__ , name , parent_inode_xp ); // get child inode cluster and local pointer cxy_t child_cxy = GET_CXY( child_inode_xp ); vfs_inode_t * child_ptr = (vfs_inode_t *)GET_PTR( child_inode_xp ); // update the child inode "type", "size", and "extend" fields vfs_inode_type_t type = (is_dir) ? INODE_TYPE_DIR : INODE_TYPE_FILE; hal_remote_sw( XPTR( child_cxy , &child_ptr->type ) , type ); hal_remote_sw( XPTR( child_cxy , &child_ptr->size ) , size ); hal_remote_sw( XPTR( child_cxy , &child_ptr->extend ) , cluster ); return 0; } } // end fatfs_inode_load()