diff -Nur linux-2.6.38.4.orig/block/genhd.c linux-2.6.38.4/block/genhd.c --- linux-2.6.38.4.orig/block/genhd.c 2011-04-21 23:34:46.000000000 +0200 +++ linux-2.6.38.4/block/genhd.c 2011-04-27 19:21:18.668912036 +0200 @@ -34,7 +34,7 @@ static DEFINE_MUTEX(ext_devt_mutex); static DEFINE_IDR(ext_devt_idr); -static struct device_type disk_type; +struct device_type disk_type; static void disk_add_events(struct gendisk *disk); static void disk_del_events(struct gendisk *disk); @@ -1118,7 +1118,7 @@ return NULL; } -static struct device_type disk_type = { +struct device_type disk_type = { .name = "disk", .groups = disk_attr_groups, .release = disk_release, diff -Nur linux-2.6.38.4.orig/init/do_mounts.c linux-2.6.38.4/init/do_mounts.c --- linux-2.6.38.4.orig/init/do_mounts.c 2011-04-21 23:34:46.000000000 +0200 +++ linux-2.6.38.4/init/do_mounts.c 2011-04-27 19:26:52.721413000 +0200 @@ -32,6 +32,132 @@ dev_t ROOT_DEV; +#ifdef CONFIG_EXT2_FS +/* support for root=UUID=ce40d6b2-18eb-4a75-aefe-7ddb0995ce63 bootargs */ + +#include + +__u8 root_dev_uuid[16]; +int root_dev_type; /* 0 = normal (/dev/hda1, 0301); 1 = UUID; 3 = bad */ + +/* imported from block/genhd.c after removing its static qualifier */ +extern struct device_type disk_type; + +/* helper function */ +static __u8 __init fromhex(char c) +{ + if (c >= '0' && c <= '9') + return (c - '0'); + c &= ~32; + if (c >= 'A' && c <= 'F') + return (c - 'A' + 10); + return (0xFF); +} + +static void __init parse_uuid(const char *s) +{ + int i; + __u8 j, k; + + if (strlen(s) != 36 || s[8] != '-' || s[13] != '-' || + s[18] != '-' || s[23] != '-') + goto bad_uuid; + for (i = 0; i < 16; i++) { + if (*s == '-') + ++s; + j = fromhex(*s++); + k = fromhex(*s++); + if (j == 0xFF || k == 0xFF) + goto bad_uuid; + root_dev_uuid[i] = (j << 4) | k; + } + return; + bad_uuid: + /* we cannot panic here, defer */ + root_dev_type = 3; +} + +/* from drivers/md/md.c */ +static void __init initcode_bi_complete(struct bio *bio, int error) +{ + complete((struct completion*)bio->bi_private); +} + +static int __init initcode_sync_page_read(struct block_device *bdev, + sector_t sector, int size, struct page *page) +{ + struct bio *bio = bio_alloc(GFP_NOIO, 1); + struct completion event; + int ret, rw = READ; + + rw |= REQ_SYNC; + + bio->bi_bdev = bdev; + bio->bi_sector = sector; + bio_add_page(bio, page, size, 0); + init_completion(&event); + bio->bi_private = &event; + bio->bi_end_io = initcode_bi_complete; + submit_bio(rw, bio); + wait_for_completion(&event); + + ret = test_bit(BIO_UPTODATE, &bio->bi_flags); + bio_put(bio); + /* 0 = failure */ + return ret; +} + +/* most of this taken from fs/ext2/super.c */ +static int __init check_dev(struct gendisk *thedisk, dev_t devt, + int blocksize, struct page *page) +{ + struct ext2_super_block * es; + struct block_device *bdev; + unsigned long sb_block = 1; + unsigned long logic_sb_block; + unsigned long offset = 0; + int rv = /* not found */ 0; + char bff[22]; + + bdev = bdget(devt); + if (blkdev_get(bdev, FMODE_READ, NULL)) { + printk(KERN_ERR "VFS: opening block device %s failed!\n", + format_dev_t(bff, devt)); + return (0); + } + + if (blocksize != BLOCK_SIZE) { + logic_sb_block = (sb_block*BLOCK_SIZE) / blocksize; + offset = (sb_block*BLOCK_SIZE) % blocksize; + } else { + logic_sb_block = sb_block; + } + +// printk(KERN_ERR "D: attempting to read %d @%lu from " +// "bdev %p devt %08X %s\n", blocksize, logic_sb_block, +// bdev, devt, format_dev_t(bff, devt)); + if (!initcode_sync_page_read(bdev, logic_sb_block, blocksize, page)) { +// printk(KERN_ERR "D: failed!\n"); + goto out; + } + es = (struct ext2_super_block *)(((char *)page_address(page)) + offset); + if (le16_to_cpu(es->s_magic) == EXT2_SUPER_MAGIC) { +// printk(KERN_ERR "D: has uuid " +// "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X\n", +// es->s_uuid[0], es->s_uuid[1], es->s_uuid[2], es->s_uuid[3], +// es->s_uuid[4], es->s_uuid[5], es->s_uuid[6], es->s_uuid[7], +// es->s_uuid[8], es->s_uuid[9], es->s_uuid[10], es->s_uuid[11], +// es->s_uuid[12], es->s_uuid[13], es->s_uuid[14], es->s_uuid[15]); + if (!memcmp(es->s_uuid, root_dev_uuid, 16)) + rv = /* found */ 1; + } +// else printk(KERN_ERR "D: bad ext2fs magic\n"); + out: + blkdev_put(bdev, FMODE_READ); + return (rv); +} +#endif /* CONFIG_EXT2_FS for UUID support */ + static int __init load_ramdisk(char *str) { rd_doload = simple_strtol(str,NULL,0) & 3; @@ -218,6 +344,13 @@ static int __init root_dev_setup(char *line) { strlcpy(saved_root_name, line, sizeof(saved_root_name)); +#ifdef CONFIG_EXT2_FS + root_dev_type = 0; + if (!strncmp(line, "UUID=", 5)) { + root_dev_type = 1; + parse_uuid(line + 5); + } +#endif /* CONFIG_EXT2_FS for UUID support */ return 1; } @@ -403,6 +536,83 @@ void __init mount_root(void) { +#ifdef CONFIG_EXT2_FS + /* UUID support */ +// printk_all_partitions(); + if (root_dev_type == 1) { + int blocksize; + + /* from block/genhd.c printk_all_partitions */ + struct class_dev_iter iter; + struct device *dev; + + /* from drivers/md/md.c */ + struct page *sb_page; + + if (!(sb_page = alloc_page(GFP_KERNEL))) { + printk(KERN_ERR "VFS: no memory for bio page\n"); + goto nomemforbio; + } + +// printk(KERN_ERR "D: root is: " +// "%02X%02X%02X%02X-%02X%02X-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X\n", +// root_dev_uuid[0], root_dev_uuid[1], root_dev_uuid[2], root_dev_uuid[3], +// root_dev_uuid[4], root_dev_uuid[5], root_dev_uuid[6], root_dev_uuid[7], +// root_dev_uuid[8], root_dev_uuid[9], root_dev_uuid[10], root_dev_uuid[11], +// root_dev_uuid[12], root_dev_uuid[13], root_dev_uuid[14], root_dev_uuid[15]); + /* from block/genhd.c printk_all_partitions */ +// printk(KERN_ERR "D: begin iter\n"); + class_dev_iter_init(&iter, &block_class, NULL, &disk_type); + while (root_dev_type && (dev = class_dev_iter_next(&iter))) { +// char bff[22]; + struct gendisk *disk = dev_to_disk(dev); + struct disk_part_iter piter; + struct hd_struct *part; + if (get_capacity(disk) == 0 || + (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) { +// printk(KERN_ERR "D: ignoring\n"); + continue; + } + blocksize = queue_logical_block_size(disk->queue); +// printk(KERN_ERR "D: gendisk, blocksize %d " +// "name '%s' devt %08X %s #part %d\n", blocksize, +// disk->disk_name, dev->devt, +// format_dev_t(bff, dev->devt), +// disk_max_parts(disk)); + disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); + while (root_dev_type && (part = disk_part_iter_next(&piter))) { + /* avoid empty or too small partitions */ +// printk(KERN_ERR "D: part #%d start %llu " +// "nr %llu\n", part->partno, +// (__u64)part->start_sect, +// (__u64)part->nr_sects); + if (part->nr_sects < 8) + continue; + if (check_dev(disk, MKDEV(MAJOR(dev->devt), + MINOR(dev->devt) + part->partno), + blocksize, sb_page)) { + ROOT_DEV = part_devt(part); +// printk(KERN_ERR "D: got match!\n"); + // comment out below for debugging + root_dev_type = 0; + } + } + disk_part_iter_exit(&piter); + } +// printk(KERN_ERR "D: end iter\n"); + class_dev_iter_exit(&iter); + put_page(sb_page); + } + nomemforbio: + if (root_dev_type == 1) + printk(KERN_ERR "VFS: Unable to find root by UUID %s.\n", + saved_root_name + 5); + else if (root_dev_type == 3) + /* execute deferred panic from parse_uuid */ + panic("Badly formatted UUID %s was supplied as kernel " + "parameter root", saved_root_name + 5); +#endif /* CONFIG_EXT2_FS for UUID support */ + #ifdef CONFIG_ROOT_NFS if (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) { if (mount_nfs_root())