Jari Ruusu wrote:
> > Would it be worth the effort to include a this functionality into losetup?
>
> Done. It is now "losetup -R /dev/loop0", unless someone vetoes that.
"losetup -R /dev/loop0" seems to work okay on LVM2 volumes. Unpatched
ext2online tool used to resize mounted ext3 file system seems to have little
problem. If encrypted file system is mounted like this:
losetup -e AES128 -K /etc/fubar.gpg /dev/loop0 /dev/mapper/foo-bar
mount -t ext3 /dev/loop0 /mnt
Then ext2online should work without modifications (I didn't test above type
mount). However, above type mount does not detach the loop device
automatically on umount. Usually I put loop options to /etc/fstab, which is
equivalent to this type mount:
mount -t ext3 /dev/mapper/foo-bar /mnt -o loop=/dev/loop0,encryption=AES128,gpgkey=/etc/fubar.gpg
That makes umount detach the loop device automatically. But... with above
type mount options, ext2online failed to find the clear-text device
/dev/loop0 from mount options, saying it couldn't find ext3 superblock on
/dev/mapper/foo-bar. Of course it can't find any superblock in there,
because that data is encrypted.
Below is a patch that makes ext2online understand loop mount options and
makes it look for the superblock in the loop device. This patch fixed the
problem for me.
--
Jari Ruusu 1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9 DB 1D EB E3 24 0E A9 DD
--- ext2resize-1.1.19/src/ext2online.c.old Thu Sep 30 17:12:01 2004
+++ ext2resize-1.1.19/src/ext2online.c Sun Sep 18 19:43:22 2005
@@ -165,6 +165,13 @@
*dir = NULL;
}
+ /* if necessary, redirect *dev to loop device */
+ if((index2 = hasmntopt(ent, "loop")) != NULL) {
+ extern char *xstrdup(const char *);
+ char *index3 = xstrdup(index2);
+ if((index2 = strchr(index3, ',')) != NULL) *index2 = 0;
+ if(strlen(index3) > 5) *dev = index3 + 5;
+ }
again:
/* Don't copy options that "mount" parses for us */
if ((index = hasmntopt(ent, "noatime")) != NULL ||
@@ -173,6 +180,13 @@
(index = hasmntopt(ent, "nosuid")) != NULL ||
(index = hasmntopt(ent, "rw")) != NULL ||
(index = hasmntopt(ent, "sync")) != NULL ||
+ (index = hasmntopt(ent, "phash")) != NULL ||
+ (index = hasmntopt(ent, "loinit")) != NULL ||
+ (index = hasmntopt(ent, "gpgkey")) != NULL ||
+ (index = hasmntopt(ent, "gpghome")) != NULL ||
+ (index = hasmntopt(ent, "offset")) != NULL ||
+ (index = hasmntopt(ent, "sizelimit")) != NULL ||
+ (index = hasmntopt(ent, "encryption")) != NULL ||
(index = hasmntopt(ent, "loop")) != NULL) {
if ((index2 = strchr(index, ',')) == NULL)
index[0] = '\0';
-
Linux-crypto: cryptography in and on the Linux system
Archive: http://mail.nl.linux.org/linux-crypto/
