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Diffstat (limited to '')
| -rw-r--r-- | super-mbr.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/super-mbr.c b/super-mbr.c new file mode 100644 index 0000000..839f000 --- /dev/null +++ b/super-mbr.c @@ -0,0 +1,206 @@ +/* + * mdadm - manage Linux "md" devices aka RAID arrays. + * + * Copyright (C) 2010 Neil Brown <neilb@suse.de> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Neil Brown + * Email: <neil@brown.name> + * + */ + +/* + * 'mbr' is a pseudo metadata type for devices which have a + * partition table in the Master Boot Record (mbr) also known + * as a dos partition table. + * + * Obviously arrays cannot be created or assembled for this type. + * It is used to allow a new bare device to have an partition table + * added so the member partitions can then be included in other + * arrays as relevant. + * + * The meaning operations are: + * examine_super, but not brief_examine_super or export_examine + * load_super + * store_super + */ + +#include "mdadm.h" +#include "part.h" + +static void free_mbr(struct supertype *st) +{ + free(st->sb); + st->sb = NULL; +} + +static void examine_mbr(struct supertype *st, char *homehost) +{ + struct MBR *sb = st->sb; + int i; + + printf(" MBR Magic : %04x\n", sb->magic); + for (i = 0; i < MBR_PARTITIONS; i++) + /* + * Have to make every access through sb rather than using a + * pointer to the partition table (or an entry), since the + * entries are not properly aligned. + */ + if (sb->parts[i].blocks_num) + printf("Partition[%d] : %12lu sectors at %12lu (type %02x)\n", + i, + (unsigned long)__le32_to_cpu(sb->parts[i].blocks_num), + (unsigned long)__le32_to_cpu(sb->parts[i].first_sect_lba), + sb->parts[i].part_type); + +} + +static int load_super_mbr(struct supertype *st, int fd, char *devname) +{ + /* try to read an mbr + * Return + * 0 on success + * 1 cannot get record + * 2 record is meaningless + */ + struct MBR *super; + + free_mbr(st); + + if (posix_memalign((void**)&super, 512, 512) != 0) { + pr_err("could not allocate superblock\n"); + return 1; + } + + lseek(fd, 0, 0); + if (read(fd, super, sizeof(*super)) != sizeof(*super)) { + if (devname) + pr_err("Cannot read partition table on %s\n", + devname); + free(super); + return 1; + } + + if (super->magic != MBR_SIGNATURE_MAGIC) { + if (devname) + pr_err("No partition table found on %s\n", + devname); + free(super); + return 1; + } + + st->sb = super; + + if (st->ss == NULL) { + st->ss = &mbr; + st->minor_version = 0; + st->max_devs = 1; + st->info = NULL; + } + return 0; +} + +static int store_mbr(struct supertype *st, int fd) +{ + struct MBR *old, *super; + + if (posix_memalign((void**)&old, 512, 512) != 0) { + pr_err("could not allocate superblock\n"); + return 1; + } + + lseek(fd, 0, 0); + if (read(fd, old, sizeof(*old)) != sizeof(*old)) { + free(old); + return 1; + } + + super = st->sb; + memcpy(super->pad, old->pad, sizeof(super->pad)); + free(old); + lseek(fd, 0, 0); + if (write(fd, super, sizeof(*super)) != sizeof(*super)) + return 4; + fsync(fd); + ioctl(fd, BLKRRPART, 0); + return 0; +} + +static void getinfo_mbr(struct supertype *st, struct mdinfo *info, char *map) +{ + struct MBR *sb = st->sb; + int i; + + memset(&info->array, 0, sizeof(info->array)); + memset(&info->disk, 0, sizeof(info->disk)); + strcpy(info->text_version, "mbr"); + strcpy(info->name, "mbr"); + info->component_size = 0; + + for (i = 0; i < MBR_PARTITIONS ; i++) + /* + * Have to make every access through sb rather than using a + * pointer to the partition table (or an entry), since the + * entries are not properly aligned. + */ + if (sb->parts[i].blocks_num) { + unsigned long last = + (unsigned long)__le32_to_cpu(sb->parts[i].blocks_num) + + (unsigned long)__le32_to_cpu(sb->parts[i].first_sect_lba); + if (last > info->component_size) + info->component_size = last; + } + +} + +static struct supertype *match_metadata_desc(char *arg) +{ + struct supertype *st; + + if (strcmp(arg, "mbr") != 0) + return NULL; + + st = xmalloc(sizeof(*st)); + st->ss = &mbr; + st->info = NULL; + st->minor_version = 0; + st->max_devs = 1; + st->sb = NULL; + return st; +} + +static int validate_geometry(struct supertype *st, int level, + int layout, int raiddisks, + int *chunk, unsigned long long size, + unsigned long long data_offset, + char *subdev, unsigned long long *freesize, + int consistency_policy, int verbose) +{ + pr_err("mbr metadata cannot be used this way\n"); + return 0; +} + +struct superswitch mbr = { + .examine_super = examine_mbr, + .validate_geometry = validate_geometry, + .match_metadata_desc = match_metadata_desc, + .load_super = load_super_mbr, + .store_super = store_mbr, + .getinfo_super = getinfo_mbr, + .free_super = free_mbr, + .name = "mbr", +}; |