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Diffstat (limited to 'ext2ed/blockbitmap_com.c')
| -rw-r--r-- | ext2ed/blockbitmap_com.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/ext2ed/blockbitmap_com.c b/ext2ed/blockbitmap_com.c new file mode 100644 index 0000000..53e61dc --- /dev/null +++ b/ext2ed/blockbitmap_com.c @@ -0,0 +1,266 @@ +/* + +/usr/src/ext2ed/blockbitmap_com.c + +A part of the extended file system 2 disk editor. + +------------------------- +Handles the block bitmap. +------------------------- + +This file implements the commands which are specific to the blockbitmap type. + +First written on: July 5 1995 + +Copyright (C) 1995 Gadi Oxman + +*/ + +#include "config.h" +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "ext2ed.h" + +/* + +The functions in this file use the flobal structure block_bitmap_info. This structure contains the current +position in the bitmap. + +*/ + +void type_ext2_block_bitmap___entry (char *command_line) + +/* + +This function changes the current entry in the bitmap. It just changes the entry_num variable in block_bitmap_info +and dispatches a show command to show the new entry. + +*/ + +{ + unsigned long entry_num; + char *ptr,buffer [80]; + + + + ptr=parse_word (command_line,buffer); /* Get the requested entry */ + if (*ptr==0) { + wprintw (command_win,"Error - No argument specified\n"); + refresh_command_win (); return; + } + ptr=parse_word (ptr,buffer); + + entry_num=atol (buffer); + + + if (entry_num >= file_system_info.super_block.s_blocks_per_group) { /* Check if it is a valid entry number */ + + wprintw (command_win,"Error - Entry number out of bounds\n"); + refresh_command_win ();return; + } + + + + block_bitmap_info.entry_num=entry_num; /* If it is, just change entry_num and */ + strcpy (buffer,"show");dispatch (buffer); /* dispatch a show command */ +} + +void type_ext2_block_bitmap___next (char *command_line) + +/* + +This function passes to the next entry in the bitmap. We just call the above entry command. + +*/ + +{ + long entry_offset=1; + char *ptr,buffer [80]; + + ptr=parse_word (command_line,buffer); + if (*ptr!=0) { + ptr=parse_word (ptr,buffer); + entry_offset=atol (buffer); + } + + sprintf (buffer,"entry %ld",block_bitmap_info.entry_num+entry_offset); + dispatch (buffer); +} + +void type_ext2_block_bitmap___prev (char *command_line) + +{ + long entry_offset=1; + char *ptr,buffer [80]; + + ptr=parse_word (command_line,buffer); + if (*ptr!=0) { + ptr=parse_word (ptr,buffer); + entry_offset=atol (buffer); + } + + sprintf (buffer,"entry %ld",block_bitmap_info.entry_num-entry_offset); + dispatch (buffer); +} + +void type_ext2_block_bitmap___allocate (char *command_line) + +/* + +This function starts allocating block from the current position. Allocating involves setting the correct bits +in the bitmap. This function is a vector version of allocate_block below - We just run on the blocks that +we need to allocate, and call allocate_block for each one. + +*/ + +{ + long entry_num,num=1; + char *ptr,buffer [80]; + + ptr=parse_word (command_line,buffer); /* Get the number of blocks to allocate */ + if (*ptr!=0) { + ptr=parse_word (ptr,buffer); + num=atol (buffer); + } + + entry_num=block_bitmap_info.entry_num; + /* Check for limits */ + if (num > file_system_info.super_block.s_blocks_per_group-entry_num) { + wprintw (command_win,"Error - There aren't that much blocks in the group\n"); + refresh_command_win ();return; + } + + while (num) { /* And call allocate_block */ + allocate_block (entry_num); /* for each block */ + num--;entry_num++; + } + + dispatch ("show"); /* Show the result */ +} + +void type_ext2_block_bitmap___deallocate (char *command_line) + +/* This is the opposite of the above function - We call deallocate_block instead of allocate_block */ + +{ + long entry_num,num=1; + char *ptr,buffer [80]; + + ptr=parse_word (command_line,buffer); + if (*ptr!=0) { + ptr=parse_word (ptr,buffer); + num=atol (buffer); + } + + entry_num=block_bitmap_info.entry_num; + if (num > file_system_info.super_block.s_blocks_per_group-entry_num) { + wprintw (command_win,"Error - There aren't that much blocks in the group\n"); + refresh_command_win ();return; + } + + while (num) { + deallocate_block (entry_num); + num--;entry_num++; + } + + dispatch ("show"); +} + + +void allocate_block (long entry_num) + +/* In this function we convert the bit number into the right byte and inner bit positions. */ + +{ + unsigned char bit_mask=1; + int byte_offset,j; + + byte_offset=entry_num/8; /* Find the correct byte - entry_num/8 */ + /* The position inside the byte is entry_num %8 */ + for (j=0;j<entry_num%8;j++) + bit_mask*=2; /* Generate the or mask - 1 at the right place */ + type_data.u.buffer [byte_offset] |= bit_mask; /* And apply it */ +} + +void deallocate_block (long entry_num) + +/* This is the opposite of allocate_block above. We use an and mask instead of an or mask. */ + +{ + unsigned char bit_mask=1; + int byte_offset,j; + + byte_offset=entry_num/8; + for (j=0;j<entry_num%8;j++) + bit_mask*=2; + bit_mask^=0xff; + + type_data.u.buffer [byte_offset] &= bit_mask; +} + +void type_ext2_block_bitmap___show (char *command_line) + +/* + +We show the bitmap as a series of bits, grouped at 8-bit intervals. We display 8 such groups on each line. +The current position (as known from block_bitmap_info.entry_num) is highlighted. + +*/ + +{ + int i,j; + unsigned char *ptr; + unsigned long block_num,entry_num; + + ptr=type_data.u.buffer; + show_pad_info.line=0;show_pad_info.max_line=-1; + + wmove (show_pad,0,0); + for (i=0,entry_num=0;i<file_system_info.super_block.s_blocks_per_group/8;i++,ptr++) { + for (j=1;j<=128;j*=2) { /* j contains the and bit mask */ + if (entry_num==block_bitmap_info.entry_num) { /* Highlight the current entry */ + wattrset (show_pad,A_REVERSE); + show_pad_info.line=show_pad_info.max_line-show_pad_info.display_lines/2; + } + + if ((*ptr) & j) /* Apply the mask */ + wprintw (show_pad,"1"); + else + wprintw (show_pad,"0"); + + if (entry_num==block_bitmap_info.entry_num) + wattrset (show_pad,A_NORMAL); + + entry_num++; /* Pass to the next entry */ + } + wprintw (show_pad," "); + if (i%8==7) { /* Display 8 groups in a row */ + wprintw (show_pad,"\n"); + show_pad_info.max_line++; + } + } + + refresh_show_pad (); + show_info (); /* Show the usual information */ + + /* Show the group number */ + wmove (show_win,1,0); + wprintw (show_win,"Block bitmap of block group %ld\n",block_bitmap_info.group_num); + /* Show the block number */ + + block_num=block_bitmap_info.entry_num+block_bitmap_info.group_num*file_system_info.super_block.s_blocks_per_group; + block_num+=file_system_info.super_block.s_first_data_block; + + wprintw (show_win,"Status of block %ld - ",block_num); /* and the allocation status */ + ptr=type_data.u.buffer+block_bitmap_info.entry_num/8; + j=1; + for (i=block_bitmap_info.entry_num % 8;i>0;i--) + j*=2; + if ((*ptr) & j) + wprintw (show_win,"Allocated\n"); + else + wprintw (show_win,"Free\n"); + refresh_show_win (); +} |