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Viewing changes to shlibs/blkid/src/topology/lvm.c

  • Committer: Package Import Robot
  • Author(s): LaMont Jones
  • Date: 2011-11-03 15:38:23 UTC
  • mto: (4.5.5 sid) (1.6.4)
  • mto: This revision was merged to the branch mainline in revision 85.
  • Revision ID: package-import@ubuntu.com-20111103153823-10sx16jprzxlhkqf
Import upstream version 2.20.1

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shlibs/blkid/src/topology/lvm.c
1
 
/*
2
 
 * lvm topology
3
 
 * -- this is fallback for old systems where the topology information is not
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 *    exported by sysfs
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 *
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 * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
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 *
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 * This file may be redistributed under the terms of the
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 * GNU Lesser General Public License.
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 *
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 */
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#include <errno.h>
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#include <fcntl.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
18
 
#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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22
 
#include "topology.h"
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24
 
#ifndef LVM_BLK_MAJOR
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# define LVM_BLK_MAJOR     58
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#endif
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static int is_lvm_device(dev_t devno)
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{
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        if (major(devno) == LVM_BLK_MAJOR)
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                return 1;
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        return blkid_driver_has_major("lvm", major(devno));
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}
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static int probe_lvm_tp(blkid_probe pr, const struct blkid_idmag *mag)
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{
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        const char *paths[] = {
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                "/usr/local/sbin/lvdisplay",
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                "/usr/sbin/lvdisplay",
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                "/sbin/lvdisplay"
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        };
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        int i, lvpipe[] = { -1, -1 }, stripes = 0, stripesize = 0;
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        FILE *stream = NULL;
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        char *cmd = NULL, *devname = NULL, buf[1024];
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        dev_t devno = blkid_probe_get_devno(pr);
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        if (!devno)
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                goto nothing;           /* probably not a block device */
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        if (!is_lvm_device(devno))
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                goto nothing;
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        for (i = 0; i < ARRAY_SIZE(paths); i++) {
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                struct stat sb;
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                if (stat(paths[i], &sb) == 0) {
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                        cmd = (char *) paths[i];
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                        break;
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                }
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        }
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        if (!cmd)
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                goto nothing;
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        devname = blkid_devno_to_devname(devno);
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        if (!devname)
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                goto nothing;
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        if (pipe(lvpipe) < 0) {
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                DBG(DEBUG_LOWPROBE,
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                        printf("Failed to open pipe: errno=%d", errno));
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                goto nothing;
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        }
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        switch (fork()) {
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        case 0:
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        {
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                char *lvargv[3];
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                /* Plumbing */
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                close(lvpipe[0]);
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                if (lvpipe[1] != STDOUT_FILENO)
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                        dup2(lvpipe[1], STDOUT_FILENO);
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                /* The libblkid library could linked with setuid programs */
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                if (setgid(getgid()) < 0)
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                         exit(1);
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                if (setuid(getuid()) < 0)
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                         exit(1);
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                lvargv[0] = cmd;
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                lvargv[1] = devname;
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                lvargv[2] = NULL;
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                execv(lvargv[0], lvargv);
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                DBG(DEBUG_LOWPROBE,
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                        printf("Failed to execute %s: errno=%d", cmd, errno));
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                exit(1);
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        }
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        case -1:
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                DBG(DEBUG_LOWPROBE,
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                        printf("Failed to forking: errno=%d", errno));
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                goto nothing;
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        default:
105
 
                break;
106
 
        }
107
 
 
108
 
        stream = fdopen(lvpipe[0], "r");
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        if (!stream)
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                goto nothing;
111
 
 
112
 
        while (fgets(buf, sizeof(buf), stream) != NULL) {
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                if (!strncmp(buf, "Stripes", 7))
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                        sscanf(buf, "Stripes %d", &stripes);
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116
 
                if (!strncmp(buf, "Stripe size", 11))
117
 
                        sscanf(buf, "Stripe size (KByte) %d", &stripesize);
118
 
        }
119
 
 
120
 
        if (!stripes)
121
 
                goto nothing;
122
 
 
123
 
        blkid_topology_set_minimum_io_size(pr, stripesize << 10);
124
 
        blkid_topology_set_optimal_io_size(pr, (stripes * stripesize) << 10);
125
 
 
126
 
        free(devname);
127
 
        fclose(stream);
128
 
        close(lvpipe[1]);
129
 
        return 0;
130
 
 
131
 
nothing:
132
 
        free(devname);
133
 
        if (stream)
134
 
                fclose(stream);
135
 
        else if (lvpipe[0] != -1)
136
 
                close(lvpipe[0]);
137
 
        if (lvpipe[1] != -1)
138
 
                close(lvpipe[1]);
139
 
        return 1;
140
 
}
141
 
 
142
 
const struct blkid_idinfo lvm_tp_idinfo =
143
 
{
144
 
        .name           = "lvm",
145
 
        .probefunc      = probe_lvm_tp,
146
 
        .magics         = BLKID_NONE_MAGIC
147
 
};
148