From 51a43b47fefaea46b00a74180a7d0b39022e6d11 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Sat, 24 Sep 2005 07:11:16 +0000 Subject: import the very fat e2fsck/fsck applets --- e2fsprogs/e2fsck/ea_refcount.c | 479 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 479 insertions(+) create mode 100644 e2fsprogs/e2fsck/ea_refcount.c (limited to 'e2fsprogs/e2fsck/ea_refcount.c') diff --git a/e2fsprogs/e2fsck/ea_refcount.c b/e2fsprogs/e2fsck/ea_refcount.c new file mode 100644 index 000000000..6420c7280 --- /dev/null +++ b/e2fsprogs/e2fsck/ea_refcount.c @@ -0,0 +1,479 @@ +/* + * ea_refcount.c + * + * Copyright (C) 2001 Theodore Ts'o. This file may be + * redistributed under the terms of the GNU Public License. + */ + +#if HAVE_UNISTD_H +#include +#endif +#include +#include + +#include "e2fsck.h" + +/* + * The strategy we use for keeping track of EA refcounts is as + * follows. We keep a sorted array of first EA blocks and its + * reference counts. Once the refcount has dropped to zero, it is + * removed from the array to save memory space. Once the EA block is + * checked, its bit is set in the block_ea_map bitmap. + */ +struct ea_refcount_el { + blk_t ea_blk; + int ea_count; +}; + +struct ea_refcount { + blk_t count; + blk_t size; + blk_t cursor; + struct ea_refcount_el *list; +}; + +void ea_refcount_free(ext2_refcount_t refcount) +{ + if (!refcount) + return; + + if (refcount->list) + ext2fs_free_mem(&refcount->list); + ext2fs_free_mem(&refcount); +} + +errcode_t ea_refcount_create(int size, ext2_refcount_t *ret) +{ + ext2_refcount_t refcount; + errcode_t retval; + size_t bytes; + + retval = ext2fs_get_mem(sizeof(struct ea_refcount), &refcount); + if (retval) + return retval; + memset(refcount, 0, sizeof(struct ea_refcount)); + + if (!size) + size = 500; + refcount->size = size; + bytes = (size_t) (size * sizeof(struct ea_refcount_el)); +#ifdef DEBUG + printf("Refcount allocated %d entries, %d bytes.\n", + refcount->size, bytes); +#endif + retval = ext2fs_get_mem(bytes, &refcount->list); + if (retval) + goto errout; + memset(refcount->list, 0, bytes); + + refcount->count = 0; + refcount->cursor = 0; + + *ret = refcount; + return 0; + +errout: + ea_refcount_free(refcount); + return(retval); +} + +/* + * collapse_refcount() --- go through the refcount array, and get rid + * of any count == zero entries + */ +static void refcount_collapse(ext2_refcount_t refcount) +{ + unsigned int i, j; + struct ea_refcount_el *list; + + list = refcount->list; + for (i = 0, j = 0; i < refcount->count; i++) { + if (list[i].ea_count) { + if (i != j) + list[j] = list[i]; + j++; + } + } +#if defined(DEBUG) || defined(TEST_PROGRAM) + printf("Refcount_collapse: size was %d, now %d\n", + refcount->count, j); +#endif + refcount->count = j; +} + + +/* + * insert_refcount_el() --- Insert a new entry into the sorted list at a + * specified position. + */ +static struct ea_refcount_el *insert_refcount_el(ext2_refcount_t refcount, + blk_t blk, int pos) +{ + struct ea_refcount_el *el; + errcode_t retval; + blk_t new_size = 0; + int num; + + if (refcount->count >= refcount->size) { + new_size = refcount->size + 100; +#ifdef DEBUG + printf("Reallocating refcount %d entries...\n", new_size); +#endif + retval = ext2fs_resize_mem((size_t) refcount->size * + sizeof(struct ea_refcount_el), + (size_t) new_size * + sizeof(struct ea_refcount_el), + &refcount->list); + if (retval) + return 0; + refcount->size = new_size; + } + num = (int) refcount->count - pos; + if (num < 0) + return 0; /* should never happen */ + if (num) { + memmove(&refcount->list[pos+1], &refcount->list[pos], + sizeof(struct ea_refcount_el) * num); + } + refcount->count++; + el = &refcount->list[pos]; + el->ea_count = 0; + el->ea_blk = blk; + return el; +} + + +/* + * get_refcount_el() --- given an block number, try to find refcount + * information in the sorted list. If the create flag is set, + * and we can't find an entry, create one in the sorted list. + */ +static struct ea_refcount_el *get_refcount_el(ext2_refcount_t refcount, + blk_t blk, int create) +{ + float range; + int low, high, mid; + blk_t lowval, highval; + + if (!refcount || !refcount->list) + return 0; +retry: + low = 0; + high = (int) refcount->count-1; + if (create && ((refcount->count == 0) || + (blk > refcount->list[high].ea_blk))) { + if (refcount->count >= refcount->size) + refcount_collapse(refcount); + + return insert_refcount_el(refcount, blk, + (unsigned) refcount->count); + } + if (refcount->count == 0) + return 0; + + if (refcount->cursor >= refcount->count) + refcount->cursor = 0; + if (blk == refcount->list[refcount->cursor].ea_blk) + return &refcount->list[refcount->cursor++]; +#ifdef DEBUG + printf("Non-cursor get_refcount_el: %u\n", blk); +#endif + while (low <= high) { +#if 0 + mid = (low+high)/2; +#else + if (low == high) + mid = low; + else { + /* Interpolate for efficiency */ + lowval = refcount->list[low].ea_blk; + highval = refcount->list[high].ea_blk; + + if (blk < lowval) + range = 0; + else if (blk > highval) + range = 1; + else + range = ((float) (blk - lowval)) / + (highval - lowval); + mid = low + ((int) (range * (high-low))); + } +#endif + if (blk == refcount->list[mid].ea_blk) { + refcount->cursor = mid+1; + return &refcount->list[mid]; + } + if (blk < refcount->list[mid].ea_blk) + high = mid-1; + else + low = mid+1; + } + /* + * If we need to create a new entry, it should be right at + * low (where high will be left at low-1). + */ + if (create) { + if (refcount->count >= refcount->size) { + refcount_collapse(refcount); + if (refcount->count < refcount->size) + goto retry; + } + return insert_refcount_el(refcount, blk, low); + } + return 0; +} + +errcode_t ea_refcount_fetch(ext2_refcount_t refcount, blk_t blk, + int *ret) +{ + struct ea_refcount_el *el; + + el = get_refcount_el(refcount, blk, 0); + if (!el) { + *ret = 0; + return 0; + } + *ret = el->ea_count; + return 0; +} + +errcode_t ea_refcount_increment(ext2_refcount_t refcount, blk_t blk, int *ret) +{ + struct ea_refcount_el *el; + + el = get_refcount_el(refcount, blk, 1); + if (!el) + return EXT2_ET_NO_MEMORY; + el->ea_count++; + + if (ret) + *ret = el->ea_count; + return 0; +} + +errcode_t ea_refcount_decrement(ext2_refcount_t refcount, blk_t blk, int *ret) +{ + struct ea_refcount_el *el; + + el = get_refcount_el(refcount, blk, 0); + if (!el || el->ea_count == 0) + return EXT2_ET_INVALID_ARGUMENT; + + el->ea_count--; + + if (ret) + *ret = el->ea_count; + return 0; +} + +errcode_t ea_refcount_store(ext2_refcount_t refcount, blk_t blk, int count) +{ + struct ea_refcount_el *el; + + /* + * Get the refcount element + */ + el = get_refcount_el(refcount, blk, count ? 1 : 0); + if (!el) + return count ? EXT2_ET_NO_MEMORY : 0; + el->ea_count = count; + return 0; +} + +blk_t ext2fs_get_refcount_size(ext2_refcount_t refcount) +{ + if (!refcount) + return 0; + + return refcount->size; +} + +void ea_refcount_intr_begin(ext2_refcount_t refcount) +{ + refcount->cursor = 0; +} + + +blk_t ea_refcount_intr_next(ext2_refcount_t refcount, + int *ret) +{ + struct ea_refcount_el *list; + + while (1) { + if (refcount->cursor >= refcount->count) + return 0; + list = refcount->list; + if (list[refcount->cursor].ea_count) { + if (ret) + *ret = list[refcount->cursor].ea_count; + return list[refcount->cursor++].ea_blk; + } + refcount->cursor++; + } +} + + +#ifdef TEST_PROGRAM + +errcode_t ea_refcount_validate(ext2_refcount_t refcount, FILE *out) +{ + errcode_t ret = 0; + int i; + const char *bad = "bad refcount"; + + if (refcount->count > refcount->size) { + fprintf(out, "%s: count > size\n", bad); + return EXT2_ET_INVALID_ARGUMENT; + } + for (i=1; i < refcount->count; i++) { + if (refcount->list[i-1].ea_blk >= refcount->list[i].ea_blk) { + fprintf(out, "%s: list[%d].blk=%u, list[%d].blk=%u\n", + bad, i-1, refcount->list[i-1].ea_blk, + i, refcount->list[i].ea_blk); + ret = EXT2_ET_INVALID_ARGUMENT; + } + } + return ret; +} + +#define BCODE_END 0 +#define BCODE_CREATE 1 +#define BCODE_FREE 2 +#define BCODE_STORE 3 +#define BCODE_INCR 4 +#define BCODE_DECR 5 +#define BCODE_FETCH 6 +#define BCODE_VALIDATE 7 +#define BCODE_LIST 8 +#define BCODE_COLLAPSE 9 + +int bcode_program[] = { + BCODE_CREATE, 5, + BCODE_STORE, 3, 3, + BCODE_STORE, 4, 4, + BCODE_STORE, 1, 1, + BCODE_STORE, 8, 8, + BCODE_STORE, 2, 2, + BCODE_STORE, 4, 0, + BCODE_STORE, 2, 0, + BCODE_STORE, 6, 6, + BCODE_VALIDATE, + BCODE_STORE, 4, 4, + BCODE_STORE, 2, 2, + BCODE_FETCH, 1, + BCODE_FETCH, 2, + BCODE_INCR, 3, + BCODE_INCR, 3, + BCODE_DECR, 4, + BCODE_STORE, 4, 4, + BCODE_VALIDATE, + BCODE_STORE, 20, 20, + BCODE_STORE, 40, 40, + BCODE_STORE, 30, 30, + BCODE_STORE, 10, 10, + BCODE_DECR, 30, + BCODE_FETCH, 30, + BCODE_DECR, 2, + BCODE_DECR, 2, + BCODE_COLLAPSE, + BCODE_LIST, + BCODE_VALIDATE, + BCODE_FREE, + BCODE_END +}; + +int main(int argc, char **argv) +{ + int i = 0; + ext2_refcount_t refcount; + int size, arg; + blk_t blk; + errcode_t retval; + + while (1) { + switch (bcode_program[i++]) { + case BCODE_END: + exit(0); + case BCODE_CREATE: + size = bcode_program[i++]; + retval = ea_refcount_create(size, &refcount); + if (retval) { + com_err("ea_refcount_create", + retval, ""); + exit(1); + } else + printf("Creating refcount with size %d\n", + size); + break; + case BCODE_FREE: + ea_refcount_free(refcount); + refcount = 0; + printf("Freeing refcount\n"); + break; + case BCODE_STORE: + blk = (blk_t) bcode_program[i++]; + arg = bcode_program[i++]; + retval = ea_refcount_store(refcount, blk, arg); + printf("Storing blk %u with value %d\n", blk, arg); + if (retval) + com_err("ea_refcount_store", retval, ""); + break; + case BCODE_FETCH: + blk = (blk_t) bcode_program[i++]; + retval = ea_refcount_fetch(refcount, blk, &arg); + if (retval) + com_err("ea_refcount_fetch", retval, ""); + else + printf("bcode_fetch(%u) returns %d\n", + blk, arg); + break; + case BCODE_INCR: + blk = (blk_t) bcode_program[i++]; + retval = ea_refcount_increment(refcount, blk, + &arg); + if (retval) + com_err("ea_refcount_increment", retval, + ""); + else + printf("bcode_increment(%u) returns %d\n", + blk, arg); + break; + case BCODE_DECR: + blk = (blk_t) bcode_program[i++]; + retval = ea_refcount_decrement(refcount, blk, + &arg); + if (retval) + com_err("ea_refcount_decrement", retval, + "while decrementing blk %u", blk); + else + printf("bcode_decrement(%u) returns %d\n", + blk, arg); + break; + case BCODE_VALIDATE: + retval = ea_refcount_validate(refcount, stderr); + if (retval) + com_err("ea_refcount_validate", + retval, ""); + else + printf("Refcount validation OK.\n"); + break; + case BCODE_LIST: + ea_refcount_intr_begin(refcount); + while (1) { + blk = ea_refcount_intr_next(refcount, + &arg); + if (!blk) + break; + printf("\tblk=%u, count=%d\n", blk, + arg); + } + break; + case BCODE_COLLAPSE: + refcount_collapse(refcount); + break; + } + + } +} + +#endif -- cgit v1.2.3