diff options
Diffstat (limited to 'libblkid/lvm1.c')
-rw-r--r-- | libblkid/lvm1.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/libblkid/lvm1.c b/libblkid/lvm1.c new file mode 100644 index 000000000..632c42b71 --- /dev/null +++ b/libblkid/lvm1.c @@ -0,0 +1,150 @@ +/* + * lvm topology + * -- this is fallback for old systems where the topology information is not + * exported by sysfs + * + * Copyright (C) 2009 Karel Zak <kzak@redhat.com> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * + */ +#include <errno.h> +#include <fcntl.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "topology.h" + +#ifndef LVM_BLK_MAJOR +# define LVM_BLK_MAJOR 58 +#endif + +static int is_lvm_device(dev_t devno) +{ + if (major(devno) == LVM_BLK_MAJOR) + return 1; + return blkid_driver_has_major("lvm", major(devno)); +} + +static int probe_lvm_tp(blkid_probe pr, + const struct blkid_idmag *mag __attribute__((__unused__))) +{ + const char *paths[] = { + "/usr/local/sbin/lvdisplay", + "/usr/sbin/lvdisplay", + "/sbin/lvdisplay" + }; + int lvpipe[] = { -1, -1 }, stripes = 0, stripesize = 0; + FILE *stream = NULL; + char *cmd = NULL, *devname = NULL, buf[1024]; + size_t i; + dev_t devno = blkid_probe_get_devno(pr); + + if (!devno) + goto nothing; /* probably not a block device */ + if (!is_lvm_device(devno)) + goto nothing; + + for (i = 0; i < ARRAY_SIZE(paths); i++) { + struct stat sb; + if (stat(paths[i], &sb) == 0) { + cmd = (char *) paths[i]; + break; + } + } + + if (!cmd) + goto nothing; + + devname = blkid_devno_to_devname(devno); + if (!devname) + goto nothing; + + if (pipe(lvpipe) < 0) { + DBG(DEBUG_LOWPROBE, + printf("Failed to open pipe: errno=%d", errno)); + goto nothing; + } + + switch (fork()) { + case 0: + { + char *lvargv[3]; + + /* Plumbing */ + close(lvpipe[0]); + + if (lvpipe[1] != STDOUT_FILENO) + dup2(lvpipe[1], STDOUT_FILENO); + + /* The libblkid library could linked with setuid programs */ + if (setgid(getgid()) < 0) + exit(1); + if (setuid(getuid()) < 0) + exit(1); + + lvargv[0] = cmd; + lvargv[1] = devname; + lvargv[2] = NULL; + + execv(lvargv[0], lvargv); + + DBG(DEBUG_LOWPROBE, + printf("Failed to execute %s: errno=%d", cmd, errno)); + exit(1); + } + case -1: + DBG(DEBUG_LOWPROBE, + printf("Failed to forking: errno=%d", errno)); + goto nothing; + default: + break; + } + + stream = fdopen(lvpipe[0], "r"); + if (!stream) + goto nothing; + + while (fgets(buf, sizeof(buf), stream) != NULL) { + if (!strncmp(buf, "Stripes", 7)) + sscanf(buf, "Stripes %d", &stripes); + + if (!strncmp(buf, "Stripe size", 11)) + sscanf(buf, "Stripe size (KByte) %d", &stripesize); + } + + if (!stripes) + goto nothing; + + blkid_topology_set_minimum_io_size(pr, stripesize << 10); + blkid_topology_set_optimal_io_size(pr, (stripes * stripesize) << 10); + + free(devname); + fclose(stream); + close(lvpipe[1]); + return 0; + +nothing: + free(devname); + if (stream) + fclose(stream); + else if (lvpipe[0] != -1) + close(lvpipe[0]); + if (lvpipe[1] != -1) + close(lvpipe[1]); + return 1; +} + +const struct blkid_idinfo lvm_tp_idinfo = +{ + .name = "lvm", + .probefunc = probe_lvm_tp, + .magics = BLKID_NONE_MAGIC +}; + |