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-rw-r--r--super-gpt.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/super-gpt.c b/super-gpt.c
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index 0000000..a1e9aa9
--- /dev/null
+++ b/super-gpt.c
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+/*
+ * 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>
+ *
+ */
+
+/*
+ * 'gpt' is a pseudo metadata type for devices which have a
+ * GPT 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_gpt(struct supertype *st)
+{
+ free(st->sb);
+ st->sb = NULL;
+}
+
+static void examine_gpt(struct supertype *st, char *homehost)
+{
+ struct GPT *gpt = st->sb + 512;
+ struct GPT_part_entry *gpe = st->sb + 1024;
+ unsigned int i;
+
+ printf(" GPT Magic : %llx\n", (unsigned long long)__le64_to_cpu(gpt->magic));
+ printf(" GPT Revision : %ld\n", (long)__le32_to_cpu(gpt->revision));
+ for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
+ printf(" Partition[%02d] : %12llu sectors at %12llu\n",
+ i,
+ (unsigned long long)__le64_to_cpu(gpe[i].starting_lba),
+ (unsigned long long)__le64_to_cpu(gpe[i].ending_lba)-
+ (unsigned long long)__le64_to_cpu(gpe[i].starting_lba)
+ +1
+ );
+ }
+}
+
+static int load_gpt(struct supertype *st, int fd, char *devname)
+{
+ struct MBR *super;
+ struct GPT *gpt_head;
+ int to_read;
+ unsigned int sector_size;
+
+ free_gpt(st);
+
+ if (posix_memalign((void**)&super, 4096, 32*512) != 0) {
+ pr_err("could not allocate superblock\n");
+ return 1;
+ }
+
+ if (!get_dev_sector_size(fd, devname, &sector_size)) {
+ free(super);
+ return 1;
+ }
+
+ lseek(fd, 0, 0);
+ if (read(fd, super, sizeof(*super)) != sizeof(*super)) {
+ no_read:
+ if (devname)
+ pr_err("Cannot read partition table on %s\n",
+ devname);
+ free(super);
+ return 1;
+ }
+
+ if (super->magic != MBR_SIGNATURE_MAGIC ||
+ super->parts[0].part_type != MBR_GPT_PARTITION_TYPE) {
+ not_found:
+ if (devname)
+ pr_err("No partition table found on %s\n",
+ devname);
+ free(super);
+ return 1;
+ }
+ /* Set offset to second block (GPT header) */
+ lseek(fd, sector_size, SEEK_SET);
+ /* Seem to have GPT, load the header */
+ gpt_head = (struct GPT*)(super+1);
+ if (read(fd, gpt_head, sizeof(*gpt_head)) != sizeof(*gpt_head))
+ goto no_read;
+ if (gpt_head->magic != GPT_SIGNATURE_MAGIC)
+ goto not_found;
+ if (__le32_to_cpu(gpt_head->part_cnt) >= 128)
+ goto not_found;
+
+ to_read = __le32_to_cpu(gpt_head->part_cnt) * sizeof(struct GPT_part_entry);
+ to_read = ((to_read+511)/512) * 512;
+ /* Set offset to third block (GPT entries) */
+ lseek(fd, sector_size*2, SEEK_SET);
+ if (read(fd, gpt_head+1, to_read) != to_read)
+ goto no_read;
+
+ st->sb = super;
+
+ if (st->ss == NULL) {
+ st->ss = &gpt;
+ st->minor_version = 0;
+ st->max_devs = 1;
+ st->info = NULL;
+ }
+ return 0;
+}
+
+static int store_gpt(struct supertype *st, int fd)
+{
+ /* FIXME should I save the boot loader */
+ /* need to write two copies! */
+ /* FIXME allow for blocks != 512 bytes
+ *etc
+ */
+ struct MBR *super = st->sb;
+ struct GPT *gpt;
+ int to_write;
+
+ gpt = (struct GPT*)(super+1);
+
+ to_write = __le32_to_cpu(gpt->part_cnt) * sizeof(struct GPT_part_entry);
+ to_write = ((to_write+511)/512) * 512;
+
+ lseek(fd, 0, 0);
+ if (write(fd, st->sb, to_write) != to_write)
+ return 4;
+
+ fsync(fd);
+ ioctl(fd, BLKRRPART, 0);
+ return 0;
+}
+
+static void getinfo_gpt(struct supertype *st, struct mdinfo *info, char *map)
+{
+ struct GPT *gpt = st->sb + 512;
+ struct GPT_part_entry *gpe = st->sb + 1024;
+ unsigned int i;
+
+ memset(&info->array, 0, sizeof(info->array));
+ memset(&info->disk, 0, sizeof(info->disk));
+ strcpy(info->text_version, "gpt");
+ strcpy(info->name, "gpt");
+ info->component_size = 0;
+
+ for (i = 0; i < __le32_to_cpu(gpt->part_cnt); i++) {
+ unsigned long long last =
+ (unsigned long long)__le64_to_cpu(gpe[i].ending_lba);
+ if (last > info->component_size)
+ info->component_size = last;
+ }
+}
+
+static struct supertype *match_metadata_desc(char *arg)
+{
+ struct supertype *st = xmalloc(sizeof(*st));
+
+ if (!st)
+ return st;
+ if (strcmp(arg, "gpt") != 0) {
+ free(st);
+ return NULL;
+ }
+
+ st->ss = &gpt;
+ 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("gpt metadata cannot be used this way\n");
+ return 0;
+}
+
+struct superswitch gpt = {
+ .examine_super = examine_gpt,
+ .validate_geometry = validate_geometry,
+ .match_metadata_desc = match_metadata_desc,
+ .load_super = load_gpt,
+ .store_super = store_gpt,
+ .getinfo_super = getinfo_gpt,
+ .free_super = free_gpt,
+ .name = "gpt",
+};