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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2365 | konopa | 1 | /* This file contains the procedures for support directory operations. */ |
| 2 | |||
| 3 | /* Methods: |
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| 4 | * do_sum: return total number of directory entries |
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| 5 | * do_readentry: fill in the user buffer with directory entry specified by number |
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| 6 | */ |
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| 7 | |||
| 8 | |||
| 9 | #include <stdio.h> |
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| 10 | #include "fs.h" |
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| 11 | #include "dir.h" |
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| 12 | #include "block.h" |
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| 13 | #include "inode.h" |
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| 14 | #include "param.h" |
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| 15 | |||
| 16 | |||
| 17 | int do_sum() |
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| 18 | { |
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| 19 | |||
| 20 | /* Perform dsum system call. */ |
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| 21 | |||
| 22 | inode_t *rip; |
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| 23 | int dir_count; |
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| 24 | offset_t dir_size; |
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| 25 | |||
| 26 | rip = fp->fp_workdir; |
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| 27 | dir_size = rip->i_size; |
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| 28 | |||
| 29 | /* We must calculate with both versions of directory entry sizes. */ |
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| 30 | if (rip->i_sp->s_extend) { |
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| 31 | dir_count = dir_size/DIR_ENTRY_SIZE; |
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| 32 | } |
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| 33 | else { |
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| 34 | dir_count = dir_size/DIR_ENTRY_SIZE_EX; |
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| 35 | } |
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| 36 | if (dir_size % DIR_ENTRY_SIZE_EX != 0) { |
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| 37 | print_console("dir_size % DIR_ENTRY_SIZE_EX != 0\n"); |
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| 38 | } |
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| 39 | |||
| 40 | return dir_count; |
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| 41 | } |
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| 42 | |||
| 43 | |||
| 44 | int do_readentry() |
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| 45 | { |
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| 46 | |||
| 47 | /* Perform readentry(numb, buffer) system call. */ |
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| 48 | |||
| 49 | int actual_sum, extend; |
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| 50 | offset_t pos; |
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| 51 | inode_t *rip; |
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| 52 | block_num_t b; |
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| 53 | block_t *bp; |
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| 54 | register int r; |
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| 55 | direct_t *dir; |
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| 56 | directex_t *direx; |
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| 57 | |||
| 58 | /* Get actual number of directory entries within the block. */ |
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| 59 | actual_sum = do_sum(); |
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| 60 | if (entry_number < 0 || actual_sum <= entry_number) |
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| 61 | return FS_EINVAL; |
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| 62 | |||
| 63 | rip = fp->fp_workdir; |
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| 64 | extend = rip->i_sp->s_extend; |
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| 65 | |||
| 66 | if (extend) { |
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| 67 | pos = entry_number * DIR_ENTRY_SIZE_EX; |
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| 68 | } |
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| 69 | else { |
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| 70 | pos = entry_number * DIR_ENTRY_SIZE; |
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| 71 | } |
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| 72 | |||
| 73 | /* Get number of block within the entry is. */ |
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| 74 | b = read_map(rip, pos); |
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| 75 | if (b == NO_BLOCK) |
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| 76 | return 0; |
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| 77 | |||
| 78 | bp = get_block(b); |
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| 79 | |||
| 80 | /* Copy the entry data into address space of actual consument. */ |
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| 81 | if (extend) { |
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| 82 | direx = &bp->b.b__direx[entry_number]; |
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| 83 | memcpy(fp->buffer, (void*)direx, DIR_ENTRY_SIZE_EX); |
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| 84 | } |
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| 85 | else { |
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| 86 | dir = &bp->b.b__dir[entry_number]; |
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| 87 | memcpy(fp->buffer, (void*)dir, DIR_ENTRY_SIZE); |
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| 88 | } |
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| 89 | |||
| 90 | r = (extend ? DIR_ENTRY_SIZE_EX : DIR_ENTRY_SIZE); |
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| 91 | |||
| 92 | return r; |
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| 93 | } |
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| 94 | |||
| 95 |