summaryrefslogtreecommitdiffstats
path: root/libblkid/zfs.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--libblkid/zfs.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/libblkid/zfs.c b/libblkid/zfs.c
new file mode 100644
index 000000000..b96c5df45
--- /dev/null
+++ b/libblkid/zfs.c
@@ -0,0 +1,226 @@
+/*
+ * Copyright (C) 2009-2010 by Andreas Dilger <adilger@sun.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "superblocks.h"
+
+#define VDEV_LABEL_UBERBLOCK (128 * 1024ULL)
+#define VDEV_LABEL_NVPAIR ( 16 * 1024ULL)
+#define VDEV_LABEL_SIZE (256 * 1024ULL)
+
+/* #include <sys/uberblock_impl.h> */
+#define UBERBLOCK_MAGIC 0x00bab10c /* oo-ba-bloc! */
+struct zfs_uberblock {
+ uint64_t ub_magic; /* UBERBLOCK_MAGIC */
+ uint64_t ub_version; /* SPA_VERSION */
+ uint64_t ub_txg; /* txg of last sync */
+ uint64_t ub_guid_sum; /* sum of all vdev guids */
+ uint64_t ub_timestamp; /* UTC time of last sync */
+ char ub_rootbp; /* MOS objset_phys_t */
+} __attribute__((packed));
+
+#define ZFS_TRIES 64
+#define ZFS_WANT 4
+
+#define DATA_TYPE_UINT64 8
+#define DATA_TYPE_STRING 9
+
+struct nvpair {
+ uint32_t nvp_size;
+ uint32_t nvp_unkown;
+ uint32_t nvp_namelen;
+ char nvp_name[0]; /* aligned to 4 bytes */
+ /* aligned ptr array for string arrays */
+ /* aligned array of data for value */
+};
+
+struct nvstring {
+ uint32_t nvs_type;
+ uint32_t nvs_elem;
+ uint32_t nvs_strlen;
+ unsigned char nvs_string[0];
+};
+
+struct nvuint64 {
+ uint32_t nvu_type;
+ uint32_t nvu_elem;
+ uint64_t nvu_value;
+};
+
+struct nvlist {
+ uint32_t nvl_unknown[3];
+ struct nvpair nvl_nvpair;
+};
+
+#define nvdebug(fmt, ...) do { } while(0)
+/*#define nvdebug(fmt, a...) printf(fmt, ##a)*/
+
+static void zfs_extract_guid_name(blkid_probe pr, loff_t offset)
+{
+ struct nvlist *nvl;
+ struct nvpair *nvp;
+ size_t left = 4096;
+ int found = 0;
+
+ offset = (offset & ~(VDEV_LABEL_SIZE - 1)) + VDEV_LABEL_NVPAIR;
+
+ /* Note that we currently assume that the desired fields are within
+ * the first 4k (left) of the nvlist. This is true for all pools
+ * I've seen, and simplifies this code somewhat, because we don't
+ * have to handle an nvpair crossing a buffer boundary. */
+ nvl = (struct nvlist *)blkid_probe_get_buffer(pr, offset, left);
+ if (nvl == NULL)
+ return;
+
+ nvdebug("zfs_extract: nvlist offset %llu\n", offset);
+
+ nvp = &nvl->nvl_nvpair;
+ while (left > sizeof(*nvp) && nvp->nvp_size != 0 && found < 3) {
+ int avail; /* tracks that name/value data fits in nvp_size */
+ int namesize;
+
+ nvp->nvp_size = be32_to_cpu(nvp->nvp_size);
+ nvp->nvp_namelen = be32_to_cpu(nvp->nvp_namelen);
+ avail = nvp->nvp_size - nvp->nvp_namelen - sizeof(*nvp);
+
+ nvdebug("left %zd nvp_size %u\n", left, nvp->nvp_size);
+ if (left < nvp->nvp_size || avail < 0)
+ break;
+
+ namesize = (nvp->nvp_namelen + 3) & ~3;
+
+ nvdebug("nvlist: size %u, namelen %u, name %*s\n",
+ nvp->nvp_size, nvp->nvp_namelen, nvp->nvp_namelen,
+ nvp->nvp_name);
+ if (strncmp(nvp->nvp_name, "name", nvp->nvp_namelen) == 0) {
+ struct nvstring *nvs = (void *)(nvp->nvp_name+namesize);
+
+ nvs->nvs_type = be32_to_cpu(nvs->nvs_type);
+ nvs->nvs_strlen = be32_to_cpu(nvs->nvs_strlen);
+ avail -= nvs->nvs_strlen + sizeof(*nvs);
+ nvdebug("nvstring: type %u string %*s\n", nvs->nvs_type,
+ nvs->nvs_strlen, nvs->nvs_string);
+ if (nvs->nvs_type == DATA_TYPE_STRING && avail >= 0)
+ blkid_probe_set_label(pr, nvs->nvs_string,
+ nvs->nvs_strlen);
+ found++;
+ } else if (strncmp(nvp->nvp_name, "guid",
+ nvp->nvp_namelen) == 0) {
+ struct nvuint64 *nvu = (void *)(nvp->nvp_name+namesize);
+ uint64_t nvu_value;
+
+ memcpy(&nvu_value, &nvu->nvu_value, sizeof(nvu_value));
+ nvu->nvu_type = be32_to_cpu(nvu->nvu_type);
+ nvu_value = be64_to_cpu(nvu_value);
+ avail -= sizeof(*nvu);
+ nvdebug("nvuint64: type %u value %"PRIu64"\n",
+ nvu->nvu_type, nvu_value);
+ if (nvu->nvu_type == DATA_TYPE_UINT64 && avail >= 0)
+ blkid_probe_sprintf_value(pr, "UUID_SUB",
+ "%"PRIu64, nvu_value);
+ found++;
+ } else if (strncmp(nvp->nvp_name, "pool_guid",
+ nvp->nvp_namelen) == 0) {
+ struct nvuint64 *nvu = (void *)(nvp->nvp_name+namesize);
+ uint64_t nvu_value;
+
+ memcpy(&nvu_value, &nvu->nvu_value, sizeof(nvu_value));
+ nvu->nvu_type = be32_to_cpu(nvu->nvu_type);
+ nvu_value = be64_to_cpu(nvu_value);
+ avail -= sizeof(*nvu);
+ nvdebug("nvuint64: type %u value %"PRIu64"\n",
+ nvu->nvu_type, nvu_value);
+ if (nvu->nvu_type == DATA_TYPE_UINT64 && avail >= 0)
+ blkid_probe_sprintf_uuid(pr, (unsigned char *)
+ &nvu_value,
+ sizeof(nvu_value),
+ "%"PRIu64, nvu_value);
+ found++;
+ }
+ if (left > nvp->nvp_size)
+ left -= nvp->nvp_size;
+ else
+ left = 0;
+ nvp = (struct nvpair *)((char *)nvp + nvp->nvp_size);
+ }
+}
+
+#define zdebug(fmt, ...) do {} while(0)
+/*#define zdebug(fmt, a...) printf(fmt, ##a)*/
+
+/* ZFS has 128x1kB host-endian root blocks, stored in 2 areas at the start
+ * of the disk, and 2 areas at the end of the disk. Check only some of them...
+ * #4 (@ 132kB) is the first one written on a new filesystem. */
+static int probe_zfs(blkid_probe pr,
+ const struct blkid_idmag *mag __attribute__((__unused__)))
+{
+ uint64_t swab_magic = swab64(UBERBLOCK_MAGIC);
+ struct zfs_uberblock *ub;
+ int swab_endian;
+ loff_t offset;
+ int tried;
+ int found;
+
+ zdebug("probe_zfs\n");
+ /* Look for at least 4 uberblocks to ensure a positive match */
+ for (tried = found = 0, offset = VDEV_LABEL_UBERBLOCK;
+ tried < ZFS_TRIES && found < ZFS_WANT;
+ tried++, offset += 4096) {
+ /* also try the second uberblock copy */
+ if (tried == (ZFS_TRIES / 2))
+ offset = VDEV_LABEL_SIZE + VDEV_LABEL_UBERBLOCK;
+
+ ub = (struct zfs_uberblock *)
+ blkid_probe_get_buffer(pr, offset,
+ sizeof(struct zfs_uberblock));
+ if (ub == NULL)
+ return -1;
+
+ if (ub->ub_magic == UBERBLOCK_MAGIC)
+ found++;
+
+ if ((swab_endian = (ub->ub_magic == swab_magic)))
+ found++;
+
+ zdebug("probe_zfs: found %s-endian uberblock at %llu\n",
+ swab_endian ? "big" : "little", offset >> 10);
+ }
+
+ if (found < 4)
+ return -1;
+
+ /* If we found the 4th uberblock, then we will have exited from the
+ * scanning loop immediately, and ub will be a valid uberblock. */
+ blkid_probe_sprintf_version(pr, "%" PRIu64, swab_endian ?
+ swab64(ub->ub_version) : ub->ub_version);
+
+ zfs_extract_guid_name(pr, offset);
+
+ if (blkid_probe_set_magic(pr, offset,
+ sizeof(ub->ub_magic),
+ (unsigned char *) &ub->ub_magic))
+ return -1;
+
+ return 0;
+}
+
+const struct blkid_idinfo zfs_idinfo =
+{
+ .name = "zfs_member",
+ .usage = BLKID_USAGE_RAID,
+ .probefunc = probe_zfs,
+ .minsz = 64 * 1024 * 1024,
+ .magics = BLKID_NONE_MAGIC
+};
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-13 01:03:20 +0100