[821] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Utility routines.
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| 4 | *
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| 5 | * Copyright (C) many different people.
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| 6 | * If you wrote this, please acknowledge your work.
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| 7 | *
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| 8 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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| 9 | */
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| 10 |
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| 11 | #include <stdio.h>
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| 12 | #include <stdlib.h>
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| 13 | #include <string.h>
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| 14 | #include "libbb.h"
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| 15 |
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| 16 | #define HASH_SIZE 311 /* Should be prime */
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| 17 | #define hash_inode(i) ((i) % HASH_SIZE)
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| 18 |
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| 19 | typedef struct ino_dev_hash_bucket_struct {
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| 20 | struct ino_dev_hash_bucket_struct *next;
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| 21 | ino_t ino;
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| 22 | dev_t dev;
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| 23 | char name[1];
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| 24 | } ino_dev_hashtable_bucket_t;
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| 25 |
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| 26 | static ino_dev_hashtable_bucket_t *ino_dev_hashtable[HASH_SIZE];
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| 27 |
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| 28 | /*
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| 29 | * Return 1 if statbuf->st_ino && statbuf->st_dev are recorded in
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| 30 | * `ino_dev_hashtable', else return 0
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| 31 | *
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| 32 | * If NAME is a non-NULL pointer to a character pointer, and there is
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| 33 | * a match, then set *NAME to the value of the name slot in that
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| 34 | * bucket.
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| 35 | */
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| 36 | int is_in_ino_dev_hashtable(const struct stat *statbuf, char **name)
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| 37 | {
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| 38 | ino_dev_hashtable_bucket_t *bucket;
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| 39 |
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| 40 | bucket = ino_dev_hashtable[hash_inode(statbuf->st_ino)];
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| 41 | while (bucket != NULL) {
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| 42 | if ((bucket->ino == statbuf->st_ino) &&
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| 43 | (bucket->dev == statbuf->st_dev))
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| 44 | {
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| 45 | if (name) *name = bucket->name;
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| 46 | return 1;
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| 47 | }
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| 48 | bucket = bucket->next;
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| 49 | }
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| 50 | return 0;
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| 51 | }
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| 52 |
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| 53 | /* Add statbuf to statbuf hash table */
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| 54 | void add_to_ino_dev_hashtable(const struct stat *statbuf, const char *name)
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| 55 | {
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| 56 | int i;
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| 57 | size_t s;
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| 58 | ino_dev_hashtable_bucket_t *bucket;
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| 59 |
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| 60 | i = hash_inode(statbuf->st_ino);
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| 61 | s = name ? strlen(name) : 0;
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| 62 | bucket = xmalloc(sizeof(ino_dev_hashtable_bucket_t) + s);
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| 63 | bucket->ino = statbuf->st_ino;
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| 64 | bucket->dev = statbuf->st_dev;
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| 65 | if (name)
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| 66 | strcpy(bucket->name, name);
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| 67 | else
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| 68 | bucket->name[0] = '\0';
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| 69 | bucket->next = ino_dev_hashtable[i];
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| 70 | ino_dev_hashtable[i] = bucket;
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| 71 | }
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| 72 |
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| 73 | #ifdef CONFIG_FEATURE_CLEAN_UP
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| 74 | /* Clear statbuf hash table */
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| 75 | void reset_ino_dev_hashtable(void)
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| 76 | {
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| 77 | int i;
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| 78 | ino_dev_hashtable_bucket_t *bucket;
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| 79 |
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| 80 | for (i = 0; i < HASH_SIZE; i++) {
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| 81 | while (ino_dev_hashtable[i] != NULL) {
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| 82 | bucket = ino_dev_hashtable[i]->next;
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| 83 | free(ino_dev_hashtable[i]);
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| 84 | ino_dev_hashtable[i] = bucket;
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| 85 | }
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| 86 | }
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| 87 | }
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| 88 | #endif
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