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zfs/config/kernel-misc-minor.m4

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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], [
Perform KABI checks in parallel Reduce the time required for ./configure to perform the needed KABI checks by allowing kbuild to compile multiple test cases in parallel. This was accomplished by splitting each test's source code from the logic handling whether that code could be compiled or not. By introducing this split it's possible to minimize the number of times kbuild needs to be invoked. As importantly, it means all of the tests can be built in parallel. This does require a little extra care since we expect some tests to fail, so the --keep-going (-k) option must be provided otherwise some tests may not get compiled. Furthermore, since a failure during the kbuild modpost phase will result in an early exit; the final linking phase is limited to tests which passed the initial compilation and produced an object file. Once everything has been built the configure script proceeds as previously. The only significant difference is that it now merely needs to test for the existence of a .ko file to determine the result of a given test. This vastly speeds up the entire process. New test cases should use ZFS_LINUX_TEST_SRC to declare their test source code and ZFS_LINUX_TEST_RESULT to check the result. All of the existing kernel-*.m4 files have been updated accordingly, see config/kernel-current-time.m4 for a basic example. The legacy ZFS_LINUX_TRY_COMPILE macro has been kept to handle special cases but it's use is not encouraged. master (secs) patched (secs) ------------- ---------------- autogen.sh 61 68 configure 137 24 (~17% of current run time) make -j $(nproc) 44 44 make rpms 287 150 Reviewed-by: Tony Hutter <hutter2@llnl.gov> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #8547 Closes #9132 Closes #9341
2019-10-01 19:50:34 +00:00
AC_MSG_CHECKING([whether /dev/zfs minor is available])
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
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.])
])
])