| Message ID | 1443965948-13945-1-git-send-email-maxime.hadjinlian@gmail.com |
|---|---|
| State | Changes Requested |
| Headers | show |
Dear Maxime, sorry for having kind of endorsed this patch in its v1, but now I tested it and it seems flawed in its very core (unless I'm still drunk). Maxime Hadjinlian wrote: > With systemd, inittab is useless, but it's also where we stored a 'mount > -o remount ...' to toggle the rootfs ro/rw at the demand of the user. > > Instead, doing a simple 'mount -a -o remount' should change the flag of > every mountpoint by reading /etc/fstab. Maybe it should, but it doesn't: # cat /etc/fstab # <file system> <mount pt> <type> <options> <dump> <pass> /dev/root / ext2 rw,noauto 0 1 proc /proc proc defaults 0 0 devpts /dev/pts devpts defaults,gid=5,mode=620 0 0 tmpfs /dev/shm tmpfs mode=0777 0 0 tmpfs /tmp tmpfs mode=1777 0 0 tmpfs /run tmpfs mode=0755,nosuid,nodev 0 0 sysfs /sys sysfs defaults 0 0 # mount /dev/root on / type ext2 (ro,relatime,errors=remount-ro) devtmpfs on /dev type devtmpfs (rw,relatime,size=62812k,nr_inodes=15703,mode=755) proc on /proc type proc (rw,relatime) # /bin/mount -a -o remount # mount /dev/root on / type ext2 (ro,relatime,errors=remount-ro) devtmpfs on /dev type devtmpfs (rw,relatime,size=62812k,nr_inodes=15703,mode=755) proc on /proc type proc (rw,relatime) # It's still mounted ro. Removing the noauto for /dev/root/ does not change the result. This is using the default mount from busybox on qemu_arm_versatile_defconfig with an external toolchain. Wild guess: are you using the full-featured mount command from util-linux? Or maybe systemd ships it own mount command with this feature?
Hi Luca, On Thu, Oct 8, 2015 at 12:03 AM, Luca Ceresoli <luca@lucaceresoli.net> wrote: > Dear Maxime, > > sorry for having kind of endorsed this patch in its v1, but now I > tested it and it seems flawed in its very core (unless I'm still drunk). > > Maxime Hadjinlian wrote: > >> With systemd, inittab is useless, but it's also where we stored a 'mount >> -o remount ...' to toggle the rootfs ro/rw at the demand of the user. >> >> Instead, doing a simple 'mount -a -o remount' should change the flag of >> every mountpoint by reading /etc/fstab. >> > > Maybe it should, but it doesn't: > > # cat /etc/fstab > # <file system> <mount pt> <type> <options> <dump> <pass> > /dev/root / ext2 rw,noauto 0 1 > proc /proc proc defaults 0 0 > devpts /dev/pts devpts defaults,gid=5,mode=620 0 0 > tmpfs /dev/shm tmpfs mode=0777 0 0 > tmpfs /tmp tmpfs mode=1777 0 0 > tmpfs /run tmpfs mode=0755,nosuid,nodev 0 0 > sysfs /sys sysfs defaults 0 0 > # mount > /dev/root on / type ext2 (ro,relatime,errors=remount-ro) > devtmpfs on /dev type devtmpfs > (rw,relatime,size=62812k,nr_inodes=15703,mode=755) > proc on /proc type proc (rw,relatime) > # /bin/mount -a -o remount > # mount > /dev/root on / type ext2 (ro,relatime,errors=remount-ro) > devtmpfs on /dev type devtmpfs > (rw,relatime,size=62812k,nr_inodes=15703,mode=755) > proc on /proc type proc (rw,relatime) > # > > It's still mounted ro. Removing the noauto for /dev/root/ does not > change the result. > > This is using the default mount from busybox on > qemu_arm_versatile_defconfig with an external toolchain. Wild guess: are > you using the full-featured mount command from util-linux? Or maybe > systemd ships it own mount command with this feature? > I'll test this on my side, I remember it worked (I created this patch during the Buildroot Summer Camp and had not sent it yet, but I clearly remember having testing it), as you said, maybe I was util the full blown mount, I'll test and respin. I'll mark this as "Changes Requested" for the moment. > > > -- > Luca >
diff --git a/package/busybox/inittab b/package/busybox/inittab index 24d9199..7202474 100644 --- a/package/busybox/inittab +++ b/package/busybox/inittab @@ -15,10 +15,9 @@ # Startup the system ::sysinit:/bin/mount -t proc proc /proc -::sysinit:/bin/mount -o remount,rw / ::sysinit:/bin/mkdir -p /dev/pts ::sysinit:/bin/mkdir -p /dev/shm -::sysinit:/bin/mount -a +::sysinit:/bin/mount -a -o remount ::sysinit:/bin/hostname -F /etc/hostname # now run any rc scripts ::sysinit:/etc/init.d/rcS diff --git a/package/skeleton/skeleton.mk b/package/skeleton/skeleton.mk index 48e7085..ae8f429 100644 --- a/package/skeleton/skeleton.mk +++ b/package/skeleton/skeleton.mk @@ -142,14 +142,14 @@ endif ifeq ($(BR2_INIT_BUSYBOX)$(BR2_INIT_SYSV),y) ifeq ($(BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW),y) -# Find commented line, if any, and remove leading '#'s +# Find 'ro,' (avoid 'root') in the first line and change it to 'rw,' define SKELETON_SYSTEM_REMOUNT_RW - $(SED) '/^#.*-o remount,rw \/$$/s~^#\+~~' $(TARGET_DIR)/etc/inittab + $(SED) '0,/ro,/s/ro,/rw,/' $(TARGET_DIR)/etc/fstab endef else -# Find uncommented line, if any, and add a leading '#' +# Find rw on the first line and change it to ro define SKELETON_SYSTEM_REMOUNT_RW - $(SED) '/^[^#].*-o remount,rw \/$$/s~^~#~' $(TARGET_DIR)/etc/inittab + $(SED) '0,/rw/s/rw/ro/' $(TARGET_DIR)/etc/fstab endef endif TARGET_FINALIZE_HOOKS += SKELETON_SYSTEM_REMOUNT_RW diff --git a/package/sysvinit/inittab b/package/sysvinit/inittab index fc0c9b5..4b8cfd7 100644 --- a/package/sysvinit/inittab +++ b/package/sysvinit/inittab @@ -5,10 +5,9 @@ id:3:initdefault: si0::sysinit:/bin/mount -t proc proc /proc -si1::sysinit:/bin/mount -o remount,rw / si2::sysinit:/bin/mkdir -p /dev/pts si3::sysinit:/bin/mkdir -p /dev/shm -si4::sysinit:/bin/mount -a +si4::sysinit:/bin/mount -a -o remount si5::sysinit:/bin/hostname -F /etc/hostname si6::sysinit:/etc/init.d/rcS
With systemd, inittab is useless, but it's also where we stored a 'mount -o remount ...' to toggle the rootfs ro/rw at the demand of the user. Instead, doing a simple 'mount -a -o remount' should change the flag of every mountpoint by reading /etc/fstab. Therefore, we now modify /etc/fstab, which happens to be read by systemd also and so, everyone benefits. Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com> --- v1 -> v2: - Rebase on current master ('null' was removed from inittab) - 'Rework' sed expression (add quote, remove curly braces, remove useless escape of comma) --- package/busybox/inittab | 3 +-- package/skeleton/skeleton.mk | 8 ++++---- package/sysvinit/inittab | 3 +-- 3 files changed, 6 insertions(+), 8 deletions(-)