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author | Neil Brown <neilb@suse.de> | 2005-08-18 06:02:33 +0000 |
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committer | Neil Brown <neilb@suse.de> | 2005-08-18 06:02:33 +0000 |
commit | eb3b43aa2a44e590e3cb3129d1e29df45d18a22a (patch) | |
tree | e4849138e9bd8f0fc6d648ddea663df8006f2c1e | |
parent | c9fae71049e01c8807540e6673536fcda6e5fe62 (diff) | |
download | mdadm-eb3b43aa2a44e590e3cb3129d1e29df45d18a22a.tar.gz mdadm-eb3b43aa2a44e590e3cb3129d1e29df45d18a22a.tar.xz mdadm-eb3b43aa2a44e590e3cb3129d1e29df45d18a22a.zip |
Check-in swap_super.c
and update a test that uses it.
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
-rw-r--r-- | swap_super.c | 83 | ||||
-rw-r--r-- | tests/06r5swap | 4 |
2 files changed, 85 insertions, 2 deletions
diff --git a/swap_super.c b/swap_super.c new file mode 100644 index 0000000..afcedf3 --- /dev/null +++ b/swap_super.c @@ -0,0 +1,83 @@ +#include <unistd.h> +#include <stdlib.h> +#include <fcntl.h> +#include <stdio.h> +#include <sys/mount.h> +/* + * This is a tiny test program to endian-swap + * the superblock on a given device. + * We simply read 4k from where the superblock should be + * do the swap, and write it back + * Don't use this on a real array, use mdadm. + */ + +#define MD_RESERVED_BYTES (64 * 1024) +#define MD_RESERVED_SECTORS (MD_RESERVED_BYTES / 512) + +#define MD_NEW_SIZE_SECTORS(x) ((x & ~(MD_RESERVED_SECTORS - 1)) - MD_RESERVED_SECTORS) + +main(int argc, char *argv[]) +{ + int fd, i; + unsigned long size; + unsigned long long offset; + char super[4096]; + if (argc != 2) { + fprintf(stderr, "Usage: swap_super device\n"); + exit(1); + } + fd = open(argv[1], O_RDWR); + if (fd<0) { + perror(argv[1]); + exit(1); + } + if (ioctl(fd, BLKGETSIZE, &size)) { + perror("BLKGETSIZE"); + exit(1); + } + offset = MD_NEW_SIZE_SECTORS(size) * 512LL; + if (lseek64(fd, offset, 0) < 0LL) { + perror("lseek64"); + exit(1); + } + if (read(fd, super, 4096) != 4096) { + perror("read"); + exit(1); + } + + + for (i=0; i < 4096 ; i+=4) { + char t = super[i]; + super[i] = super[i+3]; + super[i+3] = t; + t=super[i+1]; + super[i+1]=super[i+2]; + super[i+2]=t; + } + /* swap the u64 events counters */ + for (i=0; i<4; i++) { + /* events_hi and events_lo */ + char t=super[32*4+7*4 +i]; + super[32*4+7*4 +i] = super[32*4+8*4 +i]; + super[32*4+8*4 +i] = t; + + /* cp_events_hi and cp_events_lo */ + t=super[32*4+9*4 +i]; + super[32*4+9*4 +i] = super[32*4+10*4 +i]; + super[32*4+10*4 +i] = t; + } + + + if (lseek64(fd, offset, 0) < 0LL) { + perror("lseek64"); + exit(1); + } + if (write(fd, super, 4096) != 4096) { + perror("write"); + exit(1); + } + exit(0); + +} + + diff --git a/tests/06r5swap b/tests/06r5swap index e414f76..6a722e8 100644 --- a/tests/06r5swap +++ b/tests/06r5swap @@ -5,11 +5,11 @@ mdadm -CR $md0 -l5 -n4 $dev0 $dev1 $dev2 $dev3 sleep 4 mdadm -S $md0 -mdadm -E --metadata=0 $dev1 | grep -v Events > $targetdir/d1 +mdadm -E --metadata=0 $dev1 > $targetdir/d1 for d in $dev0 $dev1 $dev2 $dev3 do $dir/swap_super $d done -mdadm -E --metadata=0.swap $dev1 | grep -v Events > $targetdir/d1s +mdadm -E --metadata=0.swap $dev1 > $targetdir/d1s diff -u $targetdir/d1 $targetdir/d1s mdadm --assemble --update=byteorder $md0 $dev0 $dev1 $dev2 $dev3 |