| bigbiff bigbiff | e60683a | 2013-02-22 20:55:50 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Linux Software RAID (md) topology |
| 3 | * -- this is fallback for old systems where the topology information is not |
| 4 | * exported by sysfs |
| 5 | * |
| 6 | * Copyright (C) 2009 Karel Zak <kzak@redhat.com> |
| 7 | * |
| 8 | * This file may be redistributed under the terms of the |
| 9 | * GNU Lesser General Public License. |
| 10 | * |
| 11 | */ |
| 12 | #include <errno.h> |
| 13 | #include <fcntl.h> |
| 14 | #include <stdint.h> |
| 15 | #include <stdio.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <string.h> |
| 18 | #include <sys/ioctl.h> |
| 19 | #include <sys/stat.h> |
| 20 | #include <sys/types.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | #include "topology.h" |
| 24 | |
| 25 | #ifndef MD_MAJOR |
| 26 | #define MD_MAJOR 9 |
| 27 | #endif |
| 28 | |
| 29 | #ifndef _IOT__IOTBASE_uint32_t |
| 30 | #define _IOT__IOTBASE_uint32_t IOT_SIMPLE(uint32_t) |
| 31 | #endif |
| 32 | #define _IOT_md_array_info _IOT (_IOTS(uint32_t), 18, 0, 0, 0, 0) |
| 33 | #define GET_ARRAY_INFO _IOR (MD_MAJOR, 0x11, struct md_array_info) |
| 34 | |
| 35 | struct md_array_info { |
| 36 | /* |
| 37 | * Generic constant information |
| 38 | */ |
| 39 | uint32_t major_version; |
| 40 | uint32_t minor_version; |
| 41 | uint32_t patch_version; |
| 42 | uint32_t ctime; |
| 43 | uint32_t level; |
| 44 | uint32_t size; |
| 45 | uint32_t nr_disks; |
| 46 | uint32_t raid_disks; |
| 47 | uint32_t md_minor; |
| 48 | uint32_t not_persistent; |
| 49 | |
| 50 | /* |
| 51 | * Generic state information |
| 52 | */ |
| 53 | uint32_t utime; /* 0 Superblock update time */ |
| 54 | uint32_t state; /* 1 State bits (clean, ...) */ |
| 55 | uint32_t active_disks; /* 2 Number of currently active disks */ |
| 56 | uint32_t working_disks; /* 3 Number of working disks */ |
| 57 | uint32_t failed_disks; /* 4 Number of failed disks */ |
| 58 | uint32_t spare_disks; /* 5 Number of spare disks */ |
| 59 | |
| 60 | /* |
| 61 | * Personality information |
| 62 | */ |
| 63 | uint32_t layout; /* 0 the array's physical layout */ |
| 64 | uint32_t chunk_size; /* 1 chunk size in bytes */ |
| 65 | |
| 66 | }; |
| 67 | |
| 68 | static int is_md_device(dev_t devno) |
| 69 | { |
| 70 | if (major(devno) == MD_MAJOR) |
| 71 | return 1; |
| 72 | return blkid_driver_has_major("md", major(devno)); |
| 73 | } |
| 74 | |
| 75 | static int probe_md_tp(blkid_probe pr, |
| 76 | const struct blkid_idmag *mag __attribute__((__unused__))) |
| 77 | { |
| 78 | int fd = -1; |
| 79 | dev_t disk = 0; |
| 80 | dev_t devno = blkid_probe_get_devno(pr); |
| 81 | struct md_array_info md; |
| 82 | |
| 83 | if (!devno) |
| 84 | goto nothing; /* probably not a block device */ |
| 85 | |
| 86 | if (!is_md_device(devno)) |
| 87 | goto nothing; |
| 88 | |
| 89 | if (blkid_devno_to_wholedisk(devno, NULL, 0, &disk)) |
| 90 | goto nothing; |
| 91 | |
| 92 | if (disk == devno) |
| 93 | fd = pr->fd; |
| 94 | else { |
| 95 | char *diskpath = blkid_devno_to_devname(disk); |
| 96 | |
| 97 | if (!diskpath) |
| 98 | goto nothing; |
| 99 | |
| 100 | fd = open(diskpath, O_RDONLY|O_CLOEXEC); |
| 101 | free(diskpath); |
| 102 | |
| 103 | if (fd == -1) |
| 104 | goto nothing; |
| 105 | } |
| 106 | |
| 107 | memset(&md, 0, sizeof(md)); |
| 108 | |
| 109 | if (ioctl(fd, GET_ARRAY_INFO, &md)) |
| 110 | goto nothing; |
| 111 | |
| 112 | if (fd >= 0 && fd != pr->fd) { |
| 113 | close(fd); |
| 114 | fd = -1; |
| 115 | } |
| 116 | |
| 117 | /* |
| 118 | * Ignore levels we don't want aligned (e.g. linear) |
| 119 | * and deduct disk(s) from stripe width on RAID4/5/6 |
| 120 | */ |
| 121 | switch (md.level) { |
| 122 | case 6: |
| 123 | md.raid_disks--; |
| 124 | /* fallthrough */ |
| 125 | case 5: |
| 126 | case 4: |
| 127 | md.raid_disks--; |
| 128 | /* fallthrough */ |
| 129 | case 1: |
| 130 | case 0: |
| 131 | case 10: |
| 132 | break; |
| 133 | default: |
| 134 | goto nothing; |
| 135 | } |
| 136 | |
| 137 | blkid_topology_set_minimum_io_size(pr, md.chunk_size); |
| 138 | blkid_topology_set_optimal_io_size(pr, md.chunk_size * md.raid_disks); |
| 139 | |
| 140 | return 0; |
| 141 | |
| 142 | nothing: |
| 143 | if (fd >= 0 && fd != pr->fd) |
| 144 | close(fd); |
| 145 | return 1; |
| 146 | } |
| 147 | |
| 148 | const struct blkid_idinfo md_tp_idinfo = |
| 149 | { |
| 150 | .name = "md", |
| 151 | .probefunc = probe_md_tp, |
| 152 | .magics = BLKID_NONE_MAGIC |
| 153 | }; |
| 154 | |