更改boot分区大小记录二

问题：

目前更新使用新的镜像dd到sda磁盘后， 使用partprobe通知内核目录信息已经改变，但是对sda3  sda4 格式化解密的时候失败

+ cryptsetup -q luksFormat /dev/sda3 /tmp/product/.key
+ die 4 'Stage 1, open device sda3 failed.'
+ local retval=4
+ shift
+ '[' 4 == 0 ']'
+ echo ' ** Stage 1, open device sda3 failed.'
 ** Stage 1, open device sda3 failed.
+ cryptsetup -d /tmp/product/.key luksOpen /dev/sda3 xxxxxxx
+ die 4 'Stage 2, open device sda3 failed.'
+ local retval=4
+ shift
+ '[' 4 == 0 ']'
+ echo ' ** Stage 2, open device sda3 failed.'
 ** Stage 2, open device sda3 failed.
+ mkfs.ext4 -t ext4 -L xxxxxx /dev/mapper/xxxxx
+ die 1 'Stage 3, open device sda3 failed.'
+ local retval=1
+ shift
+ '[' 1 == 0 ']'
+ echo ' ** Stage 3, open device sda3 failed.'
 ** Stage 3, open device sda3 failed.

openat(AT_FDCWD, "/dev/sda2", O_RDONLY) = 7
fstat(7, {st_mode=S_IFBLK|0600, st_rdev=makedev(8, 2), ...}) = 0
ioctl(7, BLKGETSIZE64, [128849018880])  = 0

目前看到：openat， 这是啥？？

First, openat() allows an application to avoid race conditions that could occur when using open(2) to open files in directories other than the current working directory. These race conditions result from the fact that some component of the directory prefix given to open(2) could be changed in parallel with the call to open(2). Such races can be avoided by opening a file descriptor for the target directory, and then specifying that file descriptor as the dirfd argument of openat().

Second, openat() allows the implementation of a per-thread “current working directory”, via file descriptor(s) maintained by the application. (This functionality can also be obtained by tricks based on the use of /proc/self/fd/dirfd, but less efficiently.)

 　　引入openat是方便一个进程内的各线程可拥有不同的当前目录，传统的chdir会影响整个进程，而使用openat只需要每个线程在初始化时打开一个目录(调用open)，然后就可以以openat在“当前目录”操作文件了，如：
int dirfd = open("/var"); // 相当于chdir到“/var”
int filefd = openat(dirfd, "thread1"); // 在/var目录下打开“thread1”文件

 

那为什么会出现上述错误呢？

只能调试脚本：重新制作initrd 加入调试

目前可以直接看到问题原因： 磁盘分区时出现问题， 第一个分区的开始block 不是从1 开始；但是后面安装的时候安装脚本出现问题

 >> Open device 0
+ cryptsetup -q luksFormat /dev/sda3 /tmp/product/.key
+ die 4 'Stage 1, open device sda3 failed.'
+ local retval=4
+ shift
+ '[' 4 == 0 ']'
+ echo ' ** Stage 1, open device sda3 failed.'
 ** Stage 1, open device sda3 failed.
+ exit 4
sh-4.2# 
sh-4.2#  cryptsetup -q luksFormat /dev/sda3 /tmp//.key
Device /dev/sda3 doesn't exist or access denied.
sh-4.2#  cryptsetup -q luksFormat /dev/sda3 /tmp//.key
Device /dev/sda3 doesn't exist or access denied.
sh-4.2# 
sh-4.2# ls /dev/sd
sda   sda1  sda2  sdb   sdb1  sdb2  sdb3  sdb4  sdb5  
sh-4.2# ls /dev/sd
sda   sda1  sda2  sdb   sdb1  sdb2  sdb3  sdb4  sdb5  
sh-4.2# pa        
parted     partprobe  passwd     patch      
sh-4.2# pa
parted     partprobe  passwd     patch      
sh-4.2# fdisk  -l

Disk /dev/sda: 8019 MB, 8019099648 bytes
16 heads, 32 sectors/track, 30590 cylinders
Units = cylinders of 512 * 512 = 262144 bytes

   Device Boot      Start         End      Blocks  Id System
/dev/sda1               5         404      102400  83 Linux
/dev/sda2             405         800      101376  83 Linux