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/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright (c) 2014 by Delphix. All rights reserved.
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <libzfs.h>
#include <umem.h>
#include <stdlib.h>
#include <stddef.h>
#include <sys/types.h>
#include <sys/list.h>
#include <sys/stat.h>
#include <sys/errno.h>
#define PRINT_HOLE 0x1
#define PRINT_DATA 0x2
#define PRINT_VERBOSE 0x4
extern int errno;
static void
usage(char *msg, int exit_value)
{
(void) fprintf(stderr, "getholes [-dhv] filename\n");
(void) fprintf(stderr, "%s\n", msg);
exit(exit_value);
}
typedef struct segment {
list_node_t seg_node;
int seg_type;
off_t seg_offset;
off_t seg_len;
} seg_t;
/*
* Return an appropriate whence value, depending on whether the file begins
* with a holes or data.
*/
static int
starts_with_hole(int fd)
{
off_t off;
if ((off = lseek(fd, 0, SEEK_HOLE)) == -1) {
/* ENXIO means no holes were found */
if (errno == ENXIO)
return (SEEK_DATA);
perror("lseek failed");
exit(1);
}
return (off == 0 ? SEEK_HOLE : SEEK_DATA);
}
static void
print_list(list_t *seg_list, char *fname, int options)
{
uint64_t lz_holes, bs = 0;
uint64_t hole_blks_seen = 0, data_blks_seen = 0;
seg_t *seg;
if (0 == bs)
if (zfs_get_hole_count(fname, &lz_holes, &bs) != 0) {
perror("zfs_get_hole_count");
exit(1);
}
while ((seg = list_remove_head(seg_list)) != NULL) {
if (options & PRINT_VERBOSE)
(void) fprintf(stdout, "%c %llu:%llu\n",
seg->seg_type == SEEK_HOLE ? 'h' : 'd',
seg->seg_offset, seg->seg_len);
if (seg->seg_type == SEEK_HOLE) {
hole_blks_seen += seg->seg_len / bs;
} else {
data_blks_seen += seg->seg_len / bs;
}
umem_free(seg, sizeof (seg_t));
}
/* Verify libzfs sees the same number of hole blocks found manually. */
if (lz_holes != hole_blks_seen) {
(void) fprintf(stderr, "Counted %llu holes, but libzfs found "
"%llu\n", hole_blks_seen, lz_holes);
exit(1);
}
if (options & PRINT_HOLE && options & PRINT_DATA) {
(void) fprintf(stdout, "datablks: %llu\n", data_blks_seen);
(void) fprintf(stdout, "holeblks: %llu\n", hole_blks_seen);
return;
}
if (options & PRINT_DATA)
(void) fprintf(stdout, "%llu\n", data_blks_seen);
if (options & PRINT_HOLE)
(void) fprintf(stdout, "%llu\n", hole_blks_seen);
}
int
main(int argc, char *argv[])
{
off_t len, off = 0;
int c, fd, options = 0, whence = SEEK_DATA;
struct stat statbuf;
char *fname;
list_t seg_list;
seg_t *seg = NULL;
list_create(&seg_list, sizeof (seg_t), offsetof(seg_t, seg_node));
while ((c = getopt(argc, argv, "dhv")) != -1) {
switch (c) {
case 'd':
options |= PRINT_DATA;
break;
case 'h':
options |= PRINT_HOLE;
break;
case 'v':
options |= PRINT_VERBOSE;
break;
}
}
argc -= optind;
argv += optind;
if (argc != 1)
usage("Incorrect number of arguments.", 1);
if ((fname = argv[0]) == NULL)
usage("No filename provided.", 1);
if ((fd = open(fname, O_LARGEFILE | O_RDONLY)) < 0) {
perror("open failed");
exit(1);
}
if (fstat(fd, &statbuf) != 0) {
perror("fstat failed");
exit(1);
}
len = statbuf.st_size;
whence = starts_with_hole(fd);
while ((off = lseek(fd, off, whence)) != -1) {
seg_t *s;
seg = umem_alloc(sizeof (seg_t), UMEM_DEFAULT);
seg->seg_type = whence;
seg->seg_offset = off;
list_insert_tail(&seg_list, seg);
if ((s = list_prev(&seg_list, seg)) != NULL)
s->seg_len = seg->seg_offset - s->seg_offset;
whence = whence == SEEK_HOLE ? SEEK_DATA : SEEK_HOLE;
}
if (errno != ENXIO) {
perror("lseek failed");
exit(1);
}
(void) close(fd);
/*
* If this file ends with a hole block, then populate the length of
* the last segment, otherwise this is the end of the file, so
* discard the remaining zero length segment.
*/
if (seg && seg->seg_offset != len) {
seg->seg_len = len - seg->seg_offset;
} else {
(void) list_remove_tail(&seg_list);
}
print_list(&seg_list, fname, options);
list_destroy(&seg_list);
return (0);
}
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