| Message ID | 20180129041931.28192-1-casantos@datacom.ind.br |
|---|---|
| State | Superseded |
| Headers | show |
| Series | eudev: generate /etc/udev/hwdb.bin at system startup | expand |
Hi Carlos, On Mon, Jan 29, 2018 at 02:19:31AM -0200, Carlos Santos wrote: > Programs that use libudev (e.g. lsusb, from usbutils) need the hwdb.bin > file to work properly. > > If BR2_PACKAGE_EUDEV_ENABLE_HWDB is selected then the eudev installation > populates /etc/udev/hwdb.d/ but does not genarete /etc/udev/hwdb.bin. It > must be created running "udevadm hwdb --update" on the target device. > > Signed-off-by: Carlos Santos <casantos@datacom.ind.br> > --- > package/eudev/S10udev | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/package/eudev/S10udev b/package/eudev/S10udev > index 8382bec2bb..5c25e51317 100755 > --- a/package/eudev/S10udev > +++ b/package/eudev/S10udev > @@ -25,14 +25,22 @@ UDEV_CONFIG=/etc/udev/udev.conf > test -r $UDEV_CONFIG || exit 6 > . $UDEV_CONFIG > > +UDEV_HWDB_BIN=/etc/udev/hwdb.bin > +UDEV_HWDB_D=/etc/udev/hwdb.d > + > case "$1" in > start) > printf "Populating ${udev_root:-/dev} using udev: " > printf '\000\000\000\000' > /proc/sys/kernel/hotplug > - $UDEV_BIN -d || (echo "FAIL" && exit 1) > + $UDEV_BIN -d || { echo "FAIL" && exit 1; } How is this change related to hwdb.bin generation? > udevadm trigger --type=subsystems --action=add > udevadm trigger --type=devices --action=add > - udevadm settle --timeout=30 || echo "udevadm settle failed" > + udevadm settle --timeout=30 || { echo "udevadm settle failed" && exit 1; } > + [ -d "$UDEV_HWDB_D" ] && { > + echo "done" > + printf "Compiling hardware database information $UDEV_HWDB_BIN: " > + udevadm hwdb --update || { echo "FAIL" && exit 1; } Wouldn't that break read-only /etc? > + } > echo "done" > ;; > stop) baruch
> From: "Baruch Siach" <baruch@tkos.co.il> > To: "Carlos Santos" <casantos@datacom.ind.br> > Cc: "buildroot" <buildroot@buildroot.org>, "Bernd Kuhls" <bernd.kuhls@t-online.de>, "Eric Le Bihan" > <eric.le.bihan.dev@free.fr> > Sent: Monday, January 29, 2018 3:36:03 AM > Subject: Re: [Buildroot] [PATCH] eudev: generate /etc/udev/hwdb.bin at system startup > Hi Carlos, > > On Mon, Jan 29, 2018 at 02:19:31AM -0200, Carlos Santos wrote: >> Programs that use libudev (e.g. lsusb, from usbutils) need the hwdb.bin >> file to work properly. >> >> If BR2_PACKAGE_EUDEV_ENABLE_HWDB is selected then the eudev installation >> populates /etc/udev/hwdb.d/ but does not genarete /etc/udev/hwdb.bin. It >> must be created running "udevadm hwdb --update" on the target device. >> >> Signed-off-by: Carlos Santos <casantos@datacom.ind.br> >> --- >> package/eudev/S10udev | 12 ++++++++++-- >> 1 file changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/package/eudev/S10udev b/package/eudev/S10udev >> index 8382bec2bb..5c25e51317 100755 >> --- a/package/eudev/S10udev >> +++ b/package/eudev/S10udev >> @@ -25,14 +25,22 @@ UDEV_CONFIG=/etc/udev/udev.conf >> test -r $UDEV_CONFIG || exit 6 >> . $UDEV_CONFIG >> >> +UDEV_HWDB_BIN=/etc/udev/hwdb.bin >> +UDEV_HWDB_D=/etc/udev/hwdb.d >> + >> case "$1" in >> start) >> printf "Populating ${udev_root:-/dev} using udev: " >> printf '\000\000\000\000' > /proc/sys/kernel/hotplug >> - $UDEV_BIN -d || (echo "FAIL" && exit 1) >> + $UDEV_BIN -d || { echo "FAIL" && exit 1; } > > How is this change related to hwdb.bin generation? It fixes the logic. ( ... ) runs in a subshell, so the exit does not interrupt the of the parent script. Example: $ cat /tmp/foo #!/bin/sh echo 1 (echo 2 && exit 1) echo 3 $ /tmp/foo 1 2 3 $ cat /tmp/bar #!/bin/sh echo 1 { echo 2 && exit 1; } echo 3 $ /tmp/bar 1 2 $ >> udevadm trigger --type=subsystems --action=add >> udevadm trigger --type=devices --action=add >> - udevadm settle --timeout=30 || echo "udevadm settle failed" >> + udevadm settle --timeout=30 || { echo "udevadm settle failed" && exit >> 1; } >> + [ -d "$UDEV_HWDB_D" ] && { >> + echo "done" >> + printf "Compiling hardware database information $UDEV_HWDB_BIN: " >> + udevadm hwdb --update || { echo "FAIL" && exit 1; } > > Wouldn't that break read-only /etc? The script may require some customization, as already explained in its opening comments, which is beyond the scope of this change. Notice that a read-only /etc does not break the init script. It breaks the "udevadm hwdb --update" command, as well as any command that assume a rw filesystem (and there is a lot of them). ---8<---
> From: "Carlos Santos" <casantos@datacom.ind.br> > To: "Baruch Siach" <baruch@tkos.co.il> > Cc: "Bernd Kuhls" <bernd.kuhls@t-online.de>, "Eric Le Bihan" <eric.le.bihan.dev@free.fr>, "buildroot" > <buildroot@buildroot.org> > Sent: Monday, January 29, 2018 8:37:23 AM > Subject: Re: [Buildroot] [PATCH] eudev: generate /etc/udev/hwdb.bin at system startup ---8<--- >> >> Wouldn't that break read-only /etc? > > The script may require some customization, as already explained in its > opening comments, which is beyond the scope of this change. > > Notice that a read-only /etc does not break the init script. It breaks > the "udevadm hwdb --update" command, as well as any command that assume > a rw filesystem (and there is a lot of them). Addendum: the solution would be overriding the udevhwdbbin variable in the configuration script, pointing to some read-write path (e.g. /run/udev/data/, which is under a tmpfs by default).
Hi Carlos, On Mon, Jan 29, 2018 at 08:37:23AM -0200, Carlos Santos wrote: > > From: "Baruch Siach" <baruch@tkos.co.il> > > To: "Carlos Santos" <casantos@datacom.ind.br> > > Cc: "buildroot" <buildroot@buildroot.org>, "Bernd Kuhls" <bernd.kuhls@t-online.de>, "Eric Le Bihan" > > <eric.le.bihan.dev@free.fr> > > Sent: Monday, January 29, 2018 3:36:03 AM > > Subject: Re: [Buildroot] [PATCH] eudev: generate /etc/udev/hwdb.bin at system startup > > > Hi Carlos, > > > > On Mon, Jan 29, 2018 at 02:19:31AM -0200, Carlos Santos wrote: > >> Programs that use libudev (e.g. lsusb, from usbutils) need the hwdb.bin > >> file to work properly. > >> > >> If BR2_PACKAGE_EUDEV_ENABLE_HWDB is selected then the eudev installation > >> populates /etc/udev/hwdb.d/ but does not genarete /etc/udev/hwdb.bin. It > >> must be created running "udevadm hwdb --update" on the target device. > >> > >> Signed-off-by: Carlos Santos <casantos@datacom.ind.br> > >> --- > >> package/eudev/S10udev | 12 ++++++++++-- > >> 1 file changed, 10 insertions(+), 2 deletions(-) > >> > >> diff --git a/package/eudev/S10udev b/package/eudev/S10udev > >> index 8382bec2bb..5c25e51317 100755 > >> --- a/package/eudev/S10udev > >> +++ b/package/eudev/S10udev > >> @@ -25,14 +25,22 @@ UDEV_CONFIG=/etc/udev/udev.conf > >> test -r $UDEV_CONFIG || exit 6 > >> . $UDEV_CONFIG > >> > >> +UDEV_HWDB_BIN=/etc/udev/hwdb.bin > >> +UDEV_HWDB_D=/etc/udev/hwdb.d > >> + > >> case "$1" in > >> start) > >> printf "Populating ${udev_root:-/dev} using udev: " > >> printf '\000\000\000\000' > /proc/sys/kernel/hotplug > >> - $UDEV_BIN -d || (echo "FAIL" && exit 1) > >> + $UDEV_BIN -d || { echo "FAIL" && exit 1; } > > > > How is this change related to hwdb.bin generation? > > It fixes the logic. ( ... ) runs in a subshell, so the exit does not > interrupt the of the parent script. Example: > > $ cat /tmp/foo > #!/bin/sh > echo 1 > (echo 2 && exit 1) > echo 3 > $ /tmp/foo > 1 > 2 > 3 > $ cat /tmp/bar > #!/bin/sh > echo 1 > { echo 2 && exit 1; } > echo 3 > $ /tmp/bar > 1 > 2 > $ Thanks for the explanation. I think this should better be done in a separate patch with this explanation in the commit log. > >> udevadm trigger --type=subsystems --action=add > >> udevadm trigger --type=devices --action=add > >> - udevadm settle --timeout=30 || echo "udevadm settle failed" > >> + udevadm settle --timeout=30 || { echo "udevadm settle failed" && exit > >> 1; } > >> + [ -d "$UDEV_HWDB_D" ] && { > >> + echo "done" > >> + printf "Compiling hardware database information $UDEV_HWDB_BIN: " > >> + udevadm hwdb --update || { echo "FAIL" && exit 1; } > > > > Wouldn't that break read-only /etc? > > The script may require some customization, as already explained in its > opening comments, which is beyond the scope of this change. > > Notice that a read-only /etc does not break the init script. It breaks > the "udevadm hwdb --update" command, as well as any command that assume > a rw filesystem (and there is a lot of them). It might make sense to detect read-only /etc at the beginning of this script like we do in package/initscripts/init.d/S20urandom. But I agree that this is also a separate issue. baruch
diff --git a/package/eudev/S10udev b/package/eudev/S10udev index 8382bec2bb..5c25e51317 100755 --- a/package/eudev/S10udev +++ b/package/eudev/S10udev @@ -25,14 +25,22 @@ UDEV_CONFIG=/etc/udev/udev.conf test -r $UDEV_CONFIG || exit 6 . $UDEV_CONFIG +UDEV_HWDB_BIN=/etc/udev/hwdb.bin +UDEV_HWDB_D=/etc/udev/hwdb.d + case "$1" in start) printf "Populating ${udev_root:-/dev} using udev: " printf '\000\000\000\000' > /proc/sys/kernel/hotplug - $UDEV_BIN -d || (echo "FAIL" && exit 1) + $UDEV_BIN -d || { echo "FAIL" && exit 1; } udevadm trigger --type=subsystems --action=add udevadm trigger --type=devices --action=add - udevadm settle --timeout=30 || echo "udevadm settle failed" + udevadm settle --timeout=30 || { echo "udevadm settle failed" && exit 1; } + [ -d "$UDEV_HWDB_D" ] && { + echo "done" + printf "Compiling hardware database information $UDEV_HWDB_BIN: " + udevadm hwdb --update || { echo "FAIL" && exit 1; } + } echo "done" ;; stop)
Programs that use libudev (e.g. lsusb, from usbutils) need the hwdb.bin file to work properly. If BR2_PACKAGE_EUDEV_ENABLE_HWDB is selected then the eudev installation populates /etc/udev/hwdb.d/ but does not genarete /etc/udev/hwdb.bin. It must be created running "udevadm hwdb --update" on the target device. Signed-off-by: Carlos Santos <casantos@datacom.ind.br> --- package/eudev/S10udev | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)