The anaconda folks are now using blkid instead of hand-rolled tests for filesystem type at install time, but they had one more request: Bugzilla Bug 409321: RFE: information on blkdevs "formatted" as PVs https://bugzilla.redhat.com/show_bug.cgi?id=409321 The attached patch does the right thing for me on my sample set of exactly 1 PV... Any issues with reporting back something which is not actually a filesystem ("lvm2pv") ? [root@host]# misc/blkid -c /dev/null /dev/sda2 /dev/sda2: UUID="guOQGdcOE3IafCm0190XkPZTy5fCEanQ" TYPE="lvm2pv" [root@host]# pvs -o pv_name,pv_uuid PV PV UUID /dev/sda2 guOQGd-cOE3-IafC-m019-0XkP-ZTy5-fCEanQ Bits liberally stolen from lvm2 userspace. Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> --- Index: e2fsprogs-1.40.5/lib/blkid/probe.h =================================================================== --- e2fsprogs-1.40.5.orig/lib/blkid/probe.h +++ e2fsprogs-1.40.5/lib/blkid/probe.h @@ -531,6 +531,20 @@ struct hfs_mdb { __u16 embed_blockcount; } __attribute__((packed)); +/* this is lvm's label_header & pv_header combined. */ + +#define LVM2_ID_LEN 32 + +struct lvm2_pv_label_header { + /* label_header */ + __u8 id[8]; /* LABELONE */ + __u64 sector_xl; /* Sector number of this label */ + __u32 crc_xl; /* From next field to end of sector */ + __u32 offset_xl; /* Offset from start of struct to contents */ + __u8 type[8]; /* LVM2 001 */ + /* pv_header */ + __u8 pv_uuid[LVM2_ID_LEN]; +} __attribute__ ((packed)); /* * Byte swap functions Index: e2fsprogs-1.40.5/lib/blkid/probe.c =================================================================== --- e2fsprogs-1.40.5.orig/lib/blkid/probe.c +++ e2fsprogs-1.40.5/lib/blkid/probe.c @@ -895,6 +895,64 @@ static int probe_hfsplus(struct blkid_pr return 1; } +#define LVM2_LABEL_SIZE 512 +static int lvm2_calc_crc(const void *buf, uint size) +{ + static const uint crctab[] = { + 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, + 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, + 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, + 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c + }; + uint i, crc = 0xf597a6cf; + const __u8 *data = (const __u8 *) buf; + + for (i = 0; i < size; i++) { + crc ^= *data++; + crc = (crc >> 4) ^ crctab[crc & 0xf]; + crc = (crc >> 4) ^ crctab[crc & 0xf]; + } + return crc; +} + +static int probe_lvm2(struct blkid_probe *probe, + struct blkid_magic *id __BLKID_ATTR((unused)), + unsigned char *buf) +{ + int sector = (id->bim_kboff) << 1;; + struct lvm2_pv_label_header *label; + label = (struct lvm2_pv_label_header *)buf; + + /* buf is at 0k or 1k offset; find label inside */ + if (memcmp(buf, "LABELONE", 8) == 0) { + label = (struct lvm2_pv_label_header *)buf; + } else if (memcmp(buf + 512, "LABELONE", 8) == 0) { + label = (struct lvm2_pv_label_header *)(buf + 512); + sector++; + } else { + return 1; + } + + if (blkid_le64(label->sector_xl) != sector) { + DBG(DEBUG_PROBE, + printf("LVM2: label for sector %d found at sector %d\n", + blkid_le64(label->sector_xl), sector)); + return 1; + } + + if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE - + ((void *)&label->offset_xl - (void *)label)) != + blkid_le32(label->crc_xl)) { + DBG(DEBUG_PROBE, + printf("LVM2: label checksum incorrect at sector %d\n", + sector)); + return 1; + } + + blkid_set_tag(probe->dev, "UUID", label->pv_uuid, LVM2_ID_LEN); + + return 0; +} /* * BLKID_BLK_OFFS is at least as large as the highest bim_kboff defined * in the type_array table below + bim_kbalign. @@ -988,6 +1046,10 @@ static struct blkid_magic type_array[] = { "crypt_LUKS", 0, 0, 6, "LUKS\xba\xbe", probe_luks }, { "squashfs", 0, 0, 4, "sqsh", 0 }, { "squashfs", 0, 0, 4, "hsqs", 0 }, + { "lvm2pv", 0, 0x218, 8, "LVM2 001", probe_lvm2 }, + { "lvm2pv", 0, 0x018, 8, "LVM2 001", probe_lvm2 }, + { "lvm2pv", 1, 0x018, 8, "LVM2 001", probe_lvm2 }, + { "lvm2pv", 1, 0x218, 8, "LVM2 001", probe_lvm2 }, { NULL, 0, 0, 0, NULL, NULL } }; - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
