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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 19:10:49 +0000 |
commit | cfe5e3905201349e9cf3f95d52ff4bd100bde37d (patch) | |
tree | d0baf160cbee3195249d095f85e52d20c21acf02 /libblkid/src/topology/dm.c | |
parent | Initial commit. (diff) | |
download | util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.tar.xz util-linux-cfe5e3905201349e9cf3f95d52ff4bd100bde37d.zip |
Adding upstream version 2.39.3.upstream/2.39.3
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | libblkid/src/topology/dm.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/libblkid/src/topology/dm.c b/libblkid/src/topology/dm.c new file mode 100644 index 0000000..612b5df --- /dev/null +++ b/libblkid/src/topology/dm.c @@ -0,0 +1,134 @@ +/* + * device-mapper (dm) 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" + +static int is_dm_device(dev_t devno) +{ + return blkid_driver_has_major("device-mapper", major(devno)); +} + +static int probe_dm_tp(blkid_probe pr, + const struct blkid_idmag *mag __attribute__((__unused__))) +{ + const char * const paths[] = { + "/usr/local/sbin/dmsetup", + "/usr/sbin/dmsetup", + "/sbin/dmsetup" + }; + int dmpipe[] = { -1, -1 }, stripes = 0, stripesize = 0; + const char *cmd = NULL; + FILE *stream = NULL; + long long offset = 0, size = 0; + size_t i; + dev_t devno = blkid_probe_get_devno(pr); + + if (!devno) + goto nothing; /* probably not a block device */ + if (!is_dm_device(devno)) + goto nothing; + + for (i = 0; i < ARRAY_SIZE(paths); i++) { + struct stat sb; + if (stat(paths[i], &sb) == 0) { + cmd = paths[i]; + break; + } + } + + if (!cmd) + goto nothing; + if (pipe(dmpipe) < 0) { + DBG(LOWPROBE, ul_debug("Failed to open pipe: errno=%d", errno)); + goto nothing; + } + + switch (fork()) { + case 0: + { + const char *dmargv[7]; + char maj[16], min[16]; + + /* Plumbing */ + close(dmpipe[0]); + + if (dmpipe[1] != STDOUT_FILENO) + dup2(dmpipe[1], STDOUT_FILENO); + + if (drop_permissions() != 0) + exit(1); + + snprintf(maj, sizeof(maj), "%d", major(devno)); + snprintf(min, sizeof(min), "%d", minor(devno)); + + dmargv[0] = cmd; + dmargv[1] = "table"; + dmargv[2] = "-j"; + dmargv[3] = maj; + dmargv[4] = "-m"; + dmargv[5] = min; + dmargv[6] = NULL; + + execv(dmargv[0], (char * const *) dmargv); + + DBG(LOWPROBE, ul_debug("Failed to execute %s: errno=%d", cmd, errno)); + exit(1); + } + case -1: + DBG(LOWPROBE, ul_debug("Failed to forking: errno=%d", errno)); + goto nothing; + default: + break; + } + + stream = fdopen(dmpipe[0], "r" UL_CLOEXECSTR); + if (!stream) + goto nothing; + + if (dmpipe[1] != -1) { + close(dmpipe[1]); + } + + if (fscanf(stream, "%lld %lld striped %d %d ", + &offset, &size, &stripes, &stripesize) != 0) + goto nothing; + + blkid_topology_set_minimum_io_size(pr, stripesize << 9); + blkid_topology_set_optimal_io_size(pr, (stripes * stripesize) << 9); + + fclose(stream); + return 0; + +nothing: + if (stream) + fclose(stream); + else if (dmpipe[0] != -1) + close(dmpipe[0]); + return 1; +} + +const struct blkid_idinfo dm_tp_idinfo = +{ + .name = "dm", + .probefunc = probe_dm_tp, + .magics = BLKID_NONE_MAGIC +}; + |