Archive-Team
/
zfs
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 103 Wiki Activity
zfs/config/kernel-misc-minor.m4

27 lines
878 B
Plaintext
Raw Normal View History

Add kernel module auto-loading Historically a dynamic misc minor number was registered for the /dev/zfs device in order to prevent minor number collisions. This was fine but it prevented us from being able to use the kernel module auto-loaded which requires a known reserved value. Resolve this issue by adding a configure test to find an available misc minor number which can then be used in MODULE_ALIAS_MISCDEV at build time. By adding this alias the zfs kmod is added to the list of known static-nodes and the systemd-tmpfiles-setup-dev service will create a /dev/zfs character device at boot time. This in turn allows us to update the 90-zfs.rules file to make it aware this is a static node. The upshot of this is that whenever a process (zpool, zfs, zed) opens the /dev/zfs the kmods will be automatic loaded. This even works for unprivileged users so there is no longer a need to manually load the modules at boot time. As an additional bonus the zed now no longer needs to start after the zfs-import.service since it will trigger the module load. In the unlikely event the minor number we selected conflicts with another out of tree unregistered minor number the code falls back to dynamically allocating it. In this case the modules again must be manually loaded. Note that due to the change in the method of registering the minor number the zimport.sh test case may incorrectly fail when the static node for the installed packages is created instead of the dynamic one. This issue will only transiently impact zimport.sh for this single commit when we transition and are mixing and matching methods. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> TEST_ZIMPORT_SKIP="yes" Closes #7287
2018-03-13 17:45:55 +00:00
dnl #
dnl # Determine an available miscellaneous minor number which can be used
dnl # for the /dev/zfs device. This is needed because kernel module
dnl # auto-loading depends on registering a reserved non-conflicting minor
dnl # number. Start with a large known available unreserved minor and work
dnl # our way down to lower value if a collision is detected.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_MISC_MINOR], [
AC_MSG_CHECKING([for available /dev/zfs minor])
for i in $(seq 249 -1 200); do
if ! grep -q "^#define\s\+.*_MINOR\s\+.*$i" \
${LINUX}/include/linux/miscdevice.h; then
Rename macro ZFS_MINOR due to Lustre conflict Macro ZFS_MINOR, introduced in commit a6cc9756 to record the chosen static minor number for /dev/zfs, conflicts with an existing macro in Lustre. The lustre macro (along with _MAJOR, _PATCH, _FIX) is used to record the zfsonlinux version Lustre is being built against. Since the Lustre macro came first, and is used in past versions of lustre at least going back to 2.10, it makes sense to rename the macro in ZFS instead of doing so in Lustre which would require backporting the patch. Reviewed-by: Giuseppe Di Natale <guss80@gmail.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Closes #8195
2018-12-11 00:52:49 +00:00
ZFS_DEVICE_MINOR="$i"
AC_MSG_RESULT($ZFS_DEVICE_MINOR)
AC_DEFINE_UNQUOTED([ZFS_DEVICE_MINOR],
[$ZFS_DEVICE_MINOR], [/dev/zfs minor])
Add kernel module auto-loading Historically a dynamic misc minor number was registered for the /dev/zfs device in order to prevent minor number collisions. This was fine but it prevented us from being able to use the kernel module auto-loaded which requires a known reserved value. Resolve this issue by adding a configure test to find an available misc minor number which can then be used in MODULE_ALIAS_MISCDEV at build time. By adding this alias the zfs kmod is added to the list of known static-nodes and the systemd-tmpfiles-setup-dev service will create a /dev/zfs character device at boot time. This in turn allows us to update the 90-zfs.rules file to make it aware this is a static node. The upshot of this is that whenever a process (zpool, zfs, zed) opens the /dev/zfs the kmods will be automatic loaded. This even works for unprivileged users so there is no longer a need to manually load the modules at boot time. As an additional bonus the zed now no longer needs to start after the zfs-import.service since it will trigger the module load. In the unlikely event the minor number we selected conflicts with another out of tree unregistered minor number the code falls back to dynamically allocating it. In this case the modules again must be manually loaded. Note that due to the change in the method of registering the minor number the zimport.sh test case may incorrectly fail when the static node for the installed packages is created instead of the dynamic one. This issue will only transiently impact zimport.sh for this single commit when we transition and are mixing and matching methods. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> TEST_ZIMPORT_SKIP="yes" Closes #7287
2018-03-13 17:45:55 +00:00
break
fi
done
Rename macro ZFS_MINOR due to Lustre conflict Macro ZFS_MINOR, introduced in commit a6cc9756 to record the chosen static minor number for /dev/zfs, conflicts with an existing macro in Lustre. The lustre macro (along with _MAJOR, _PATCH, _FIX) is used to record the zfsonlinux version Lustre is being built against. Since the Lustre macro came first, and is used in past versions of lustre at least going back to 2.10, it makes sense to rename the macro in ZFS instead of doing so in Lustre which would require backporting the patch. Reviewed-by: Giuseppe Di Natale <guss80@gmail.com> Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Olaf Faaland <faaland1@llnl.gov> Closes #8195
2018-12-11 00:52:49 +00:00
AS_IF([ test -z "$ZFS_DEVICE_MINOR"], [
Add kernel module auto-loading Historically a dynamic misc minor number was registered for the /dev/zfs device in order to prevent minor number collisions. This was fine but it prevented us from being able to use the kernel module auto-loaded which requires a known reserved value. Resolve this issue by adding a configure test to find an available misc minor number which can then be used in MODULE_ALIAS_MISCDEV at build time. By adding this alias the zfs kmod is added to the list of known static-nodes and the systemd-tmpfiles-setup-dev service will create a /dev/zfs character device at boot time. This in turn allows us to update the 90-zfs.rules file to make it aware this is a static node. The upshot of this is that whenever a process (zpool, zfs, zed) opens the /dev/zfs the kmods will be automatic loaded. This even works for unprivileged users so there is no longer a need to manually load the modules at boot time. As an additional bonus the zed now no longer needs to start after the zfs-import.service since it will trigger the module load. In the unlikely event the minor number we selected conflicts with another out of tree unregistered minor number the code falls back to dynamically allocating it. In this case the modules again must be manually loaded. Note that due to the change in the method of registering the minor number the zimport.sh test case may incorrectly fail when the static node for the installed packages is created instead of the dynamic one. This issue will only transiently impact zimport.sh for this single commit when we transition and are mixing and matching methods. Reviewed-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> TEST_ZIMPORT_SKIP="yes" Closes #7287
2018-03-13 17:45:55 +00:00
AC_MSG_ERROR([
*** No available misc minor numbers available for use.])
])
])