From 657cec41e61aaf926e39f8be8931df5e3422a097 Mon Sep 17 00:00:00 2001 From: Thorsten Glaser Date: Sun, 21 Nov 2010 18:39:50 +0000 Subject: let the UUID code correctly load sectors from disc using BIO Signed-off-by: Thorsten Glaser --- target/linux/patches/2.6.36/uuid.patch | 133 +++++++++++++++++++++++++++------ 1 file changed, 110 insertions(+), 23 deletions(-) (limited to 'target/linux/patches/2.6.36/uuid.patch') diff --git a/target/linux/patches/2.6.36/uuid.patch b/target/linux/patches/2.6.36/uuid.patch index 2e6c61df9..cf2869ed2 100644 --- a/target/linux/patches/2.6.36/uuid.patch +++ b/target/linux/patches/2.6.36/uuid.patch @@ -1,6 +1,7 @@ # DP: Add support for specifying the root device using UUIDs on the # DP: kernel command line like this without the need for an initrd: # DP: linux ... root=UUID=ce40d6b2-18eb-4a75-aefe-7ddb0995ce63 +# DP: Note: debugging code is kept in, commented out “//” style. # DP: # DP: Written © 2010 by Thorsten Glaser # DP: Idea from 1999 by David Balazic @@ -25,24 +26,24 @@ .name = "disk", .groups = disk_attr_groups, .release = disk_release, ---- linux-2.6.36/init/do_mounts.c~ Wed Oct 20 22:30:22 2010 -+++ linux-2.6.36/init/do_mounts.c Sat Nov 20 23:16:07 2010 -@@ -32,6 +32,84 @@ static int __initdata root_wait; +--- linux-2.6.36/init/do_mounts.c~ Wed Oct 20 20:29:58 2010 ++++ linux-2.6.36/init/do_mounts.c Sun Nov 21 18:37:36 2010 +@@ -32,6 +32,132 @@ static int __initdata root_wait; dev_t ROOT_DEV; +#ifdef CONFIG_EXT2_FS +/* support for root=UUID=ce40d6b2-18eb-4a75-aefe-7ddb0995ce63 bootargs */ + -+#include +#include + -+__u8 root_dev_label[16]; ++__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') @@ -68,7 +69,7 @@ + k = fromhex(*s++); + if (j == 0xFF || k == 0xFF) + goto bad_uuid; -+ root_dev_label[i] = (j << 4) | k; ++ root_dev_uuid[i] = (j << 4) | k; + } + return; + bad_uuid: @@ -76,19 +77,54 @@ + root_dev_type = 3; +} + -+static int __init check_dev(dev_t devt, int blocksize) ++/* from drivers/md/md.c */ ++static void __init initcode_bi_complete(struct bio *bio, int error) +{ -+ /* most of this taken from fs/ext2/super.c */ ++ 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 | REQ_UNPLUG; ++ ++ 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); + -+ struct buffer_head * bh; ++ 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 = 0; ++ int rv = /* not found */ 0; ++ char bff[22]; + + bdev = bdget(devt); ++ if (blkdev_get(bdev, FMODE_READ)) { ++ 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; @@ -97,14 +133,27 @@ + logic_sb_block = sb_block; + } + -+ if (!(bh = __bread(bdev, logic_sb_block, blocksize))) -+ return (0); -+ es = (struct ext2_super_block *)(((char *)bh->b_data) + offset); ++// 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) { -+ if (!memcmp(es->s_uuid, root_dev_label, 16)) -+ rv = 1; ++// 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; + } -+ brelse(bh); ++// else printk(KERN_ERR "D: bad ext2fs magic\n"); ++ out: ++ blkdev_put(bdev, FMODE_READ); + return (rv); +} +#endif /* CONFIG_EXT2_FS for UUID support */ @@ -112,7 +161,7 @@ static int __init load_ramdisk(char *str) { rd_doload = simple_strtol(str,NULL,0) & 3; -@@ -148,6 +226,13 @@ done: +@@ -148,6 +274,13 @@ done: static int __init root_dev_setup(char *line) { strlcpy(saved_root_name, line, sizeof(saved_root_name)); @@ -126,12 +175,13 @@ return 1; } -@@ -333,6 +418,45 @@ void __init change_floppy(char *fmt, ...) +@@ -333,6 +466,83 @@ void __init change_floppy(char *fmt, ... void __init mount_root(void) { +#ifdef CONFIG_EXT2_FS + /* UUID support */ ++// printk_all_partitions(); + if (root_dev_type == 1) { + int blocksize; + @@ -139,34 +189,71 @@ + 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)) ++ (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(part_devt(part), blocksize)) { ++ 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); ++ printk(KERN_ERR "VFS: Unable to find root by UUID %s.\n", ++ saved_root_name + 5); + else if (root_dev_type == 3) -+ panic("Badly formatted UUID %s was supplied as kernel parameter root", saved_root_name + 5); ++ /* 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 -- cgit v1.2.3