| /* |
| * Linux Software RAID (md) 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/ioctl.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| |
| #include "topology.h" |
| |
| #ifndef MD_MAJOR |
| #define MD_MAJOR 9 |
| #endif |
| |
| #ifndef _IOT__IOTBASE_uint32_t |
| #define _IOT__IOTBASE_uint32_t IOT_SIMPLE(uint32_t) |
| #endif |
| #define _IOT_md_array_info _IOT (_IOTS(uint32_t), 18, 0, 0, 0, 0) |
| #define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, struct md_array_info) |
| |
| struct md_array_info { |
| /* |
| * Generic constant information |
| */ |
| uint32_t major_version; |
| uint32_t minor_version; |
| uint32_t patch_version; |
| uint32_t ctime; |
| uint32_t level; |
| uint32_t size; |
| uint32_t nr_disks; |
| uint32_t raid_disks; |
| uint32_t md_minor; |
| uint32_t not_persistent; |
| |
| /* |
| * Generic state information |
| */ |
| uint32_t utime; /* 0 Superblock update time */ |
| uint32_t state; /* 1 State bits (clean, ...) */ |
| uint32_t active_disks; /* 2 Number of currently active disks */ |
| uint32_t working_disks; /* 3 Number of working disks */ |
| uint32_t failed_disks; /* 4 Number of failed disks */ |
| uint32_t spare_disks; /* 5 Number of spare disks */ |
| |
| /* |
| * Personality information |
| */ |
| uint32_t layout; /* 0 the array's physical layout */ |
| uint32_t chunk_size; /* 1 chunk size in bytes */ |
| |
| }; |
| |
| static int is_md_device(dev_t devno) |
| { |
| if (major(devno) == MD_MAJOR) |
| return 1; |
| return blkid_driver_has_major("md", major(devno)); |
| } |
| |
| static int probe_md_tp(blkid_probe pr, |
| const struct blkid_idmag *mag __attribute__((__unused__))) |
| { |
| int fd = -1; |
| dev_t disk = 0; |
| dev_t devno = blkid_probe_get_devno(pr); |
| struct md_array_info md; |
| |
| if (!devno) |
| goto nothing; /* probably not a block device */ |
| |
| if (!is_md_device(devno)) |
| goto nothing; |
| |
| if (blkid_devno_to_wholedisk(devno, NULL, 0, &disk)) |
| goto nothing; |
| |
| if (disk == devno) |
| fd = pr->fd; |
| else { |
| char *diskpath = blkid_devno_to_devname(disk); |
| |
| if (!diskpath) |
| goto nothing; |
| |
| fd = open(diskpath, O_RDONLY); |
| free(diskpath); |
| |
| if (fd == -1) |
| goto nothing; |
| } |
| |
| memset(&md, 0, sizeof(md)); |
| |
| if (ioctl(fd, GET_ARRAY_INFO, &md)) |
| goto nothing; |
| |
| if (fd >= 0 && fd != pr->fd) { |
| close(fd); |
| fd = -1; |
| } |
| |
| /* |
| * Ignore levels we don't want aligned (e.g. linear) |
| * and deduct disk(s) from stripe width on RAID4/5/6 |
| */ |
| switch (md.level) { |
| case 6: |
| md.raid_disks--; |
| /* fallthrough */ |
| case 5: |
| case 4: |
| md.raid_disks--; |
| /* fallthrough */ |
| case 1: |
| case 0: |
| case 10: |
| break; |
| default: |
| goto nothing; |
| } |
| |
| blkid_topology_set_minimum_io_size(pr, md.chunk_size); |
| blkid_topology_set_optimal_io_size(pr, md.chunk_size * md.raid_disks); |
| |
| return 0; |
| |
| nothing: |
| if (fd >= 0 && fd != pr->fd) |
| close(fd); |
| return 1; |
| } |
| |
| const struct blkid_idinfo md_tp_idinfo = |
| { |
| .name = "md", |
| .probefunc = probe_md_tp, |
| .magics = BLKID_NONE_MAGIC |
| }; |
| |