glusterfs

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/* seek.c - use glfs_lseek() to find holes in a file
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 *
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 * Author: Niels de Vos <ndevos@redhat.com>
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 */
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/* needed for SEEK_HOLE/SEEK_DATA */
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#ifndef _GNU_SOURCE
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#define _GNU_SOURCE
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#endif
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#include <sys/types.h>
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#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <glusterfs/api/glfs.h>
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#include <glusterfs/api/glfs-handles.h>
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int
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main(int argc, char **argv)
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{
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    glfs_t *fs = NULL;
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    int ret = 0;
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    glfs_fd_t *fd = NULL;
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    char *filename = NULL;
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    char *volname = NULL;
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    char *hostname = NULL;
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    struct stat st = {
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        0,
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    };
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    off_t hole_start = 0;
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    off_t hole_end = 0;
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    if (argc != 4) {
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        fprintf(stderr, "Invalid argument, use %s <hostname> <vol> <file>\n",
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                argv[0]);
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        exit(1);
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    }
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    hostname = argv[1];
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    volname = argv[2];
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    filename = argv[3];
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    fs = glfs_new(volname);
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    if (!fs) {
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        perror("glfs_new() returned NULL");
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        return 1;
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    }
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    if (glfs_set_volfile_server(fs, "tcp", hostname, 24007)) {
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        perror("glfs_set_volfile_server");
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        return 1;
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    }
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    if (glfs_init(fs)) {
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        perror("glfs_init");
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        return 1;
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    }
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    fd = glfs_open(fs, filename, O_RDONLY);
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    if (fd <= 0) {
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        perror("glfs_open");
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        return 1;
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    }
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    if (glfs_fstat(fd, &st)) {
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        perror("glfs_fstat");
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        return 1;
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    }
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    while (hole_end < st.st_size) {
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        hole_start = glfs_lseek(fd, hole_end, SEEK_HOLE);
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        if (hole_start == -1 && errno == ENXIO)
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            /* no more holes */
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            break;
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        if (hole_start == -1) {
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            perror("no more holes");
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            break;
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        }
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        hole_end = glfs_lseek(fd, hole_start, SEEK_DATA);
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        if (hole_end == -1 && errno == ENXIO) {
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            /* no more data */
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            break;
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        }
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        printf("HOLE found: %ld - %ld%s\n", hole_start, hole_end,
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               (hole_end == st.st_size) ? " (EOF)" : "");
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    }
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    glfs_close(fd);
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    if (fs) {
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        glfs_fini(fs);
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    }
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    return ret;
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}
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