-o remount,rw not possible?

[Christian Kujau <evil@xxxxxxxxxx>]

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hi list,

i'm using loop-aes for quite a while now and from time to time i had to
remount device-backed loop-aes partitions. eg. a normally r/o mounted
backup partition would become a r/w. i did this like so:

$ mount -o remount,rw /data

when i try this now, mount comes back with

mount: block device /dev/hda1 is write-protected, mounting read-only

i don't know exactly when it stopped working (but i'm pretty sure it
worked a month ago or so). upgrading to the latest loop-aes/ciphers
package did not help.

my setup:

root@sheep:~# losetup -a
/dev/loop5: [0805]:173 (/dev/hda1) encryption=twofish128 multi-key read-only
/dev/loop6: [0805]:380 (/dev/sda8) encryption=AES128 multi-key
/dev/loop7: [0805]:389 (/dev/sdb1) encryption=twofish128 multi-key read-only

root@sheep:~# uname -r
2.6.10-rc2-bk9

root@sheep:~# mount -V
mount: mount-2.12a      <--- stock debian util-linux

i mount the partition with

- -o ro,noexec,nosuid,nodev,noatime,loop=/dev/loop7,\
   gpgkey=/root/keys/sdb1.gpg,encryption=twofish128

(or encryption=aes128 for the aes partition)

fwiw, i've attached the (E)rrors shown from an strace during mount.

thank you for comments,
Christian.

$ strace -s256 mount -o remount,rw /data/Media/ 2>&1 | grep \ =\ -1

access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or
directory)
open("/etc/ld.so.preload", O_RDONLY)    = -1 ENOENT (No such file or
directory)
access("/etc/ld.so.nohwcap", F_OK)      = -1 ENOENT (No such file or
directory)
readlink("/data", 0xbfffec30, 4096)     = -1 EINVAL (Invalid argument)
readlink("/data/Media", 0xbfffec30, 4096) = -1 EINVAL (Invalid argument)
stat64("/sbin/mount.ext3", 0xbffffa50)  = -1 ENOENT (No such file or
directory)
mount("/dev/hda1", "/data/Media", "ext3",
MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_REMOUNT|0xc0ed0400, 0x8063bf0) = -1
EACCES (Permission denied)
stat64("/sbin/mount.ext3", 0xbffff950)  = -1 ENOENT (No such file or
directory)
readlink("/dev", 0xbfffe9b0, 4096)      = -1 EINVAL (Invalid argument)
readlink("/dev/hda1", 0xbfffe9b0, 4096) = -1 EINVAL (Invalid argument)
readlink("/data", 0xbfffe9b0, 4096)     = -1 EINVAL (Invalid argument)
readlink("/data/Media", 0xbfffe9b0, 4096) = -1 EINVAL (Invalid argument)
rt_sigaction(SIGKILL, {0x804dc10, ~[RTMIN], 0}, NULL, 8) = -1 EINVAL
(Invalid argument)

- --
BOFH excuse #427:

network down, IP packets delivered via UPS

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