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Re: [Minios-devel] [UNIKRAFT PATCH v3 3/5] lib/vfscore: Automount option
Hey Sharan,
you are right, KConfig is adding ramfs to the vfscore option list
although this was never intended this way. The problem is that we have
no clean termination for a menuconfig entry (like it exists for `menu`
and `choice`). Everything that is parsed afterwards and directly depends
on the menuconfig item, will be placed under the submenu (either via
`depends on` or `if`-statements). The divide/submenu termination is only
achieved with a config item that is not depending on the menuconfig option.
I agree that we need a different solution although the alternatives do
not look very nice. My suggestion to your solution is not to use
`visible` keyword and keep the `if` statement around your `menu` item.
This avoids that unused options are ending up in the configuration file.
I will implement this in the v4. Let me know what you think.
Thanks,
Simon
On 27.09.19 18:59, Sharan Santhanam wrote:
Hello Simon,
The patch seems to functionally correct but there seems to problem in
the display of Ramfs config options. Since the RAMFS config depends on
the LIBVFSCORE and the LIBVFSCORE is a menuconfig, the RAMFS
configuration is sucked in as a option within LIBVFSCORE menuconfig.
This behavior of RAMFS is different from the behavior of the rest of the
filesystem like 9Ps and devfs.
My suggestion would be to convert the menuconfig to menu as there is
definite way of defining the start and end of the menu. The annoyance
with this option would be it creates a separate prompt.
A snippet of how I would restructure it.
config LIBVFSCORE
bool "vfscore: VFS Core Interface"
default n
select LIBNOLIBC if !HAVE_LIBC
select LIBUKDEBUG
select LIBUKLOCK
menu "VFS Options"
visible if LIBVFSCORE
# We can add vfscore options here
endmenu
I observed there are also checkpatch error.
Thanks & Regards
Sharan
On 9/24/19 12:07 PM, Simon Kuenzer wrote:
Moves the option of automatically a rootfs to lib/vfscore. This
feature is not only useful for initializing devfs. Library parameters
to influence the default settings are provided.
Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
---
lib/devfs/Config.uk | 9 ++--
lib/devfs/devfs_vnops.c | 8 +---
lib/vfscore/Config.uk | 76 ++++++++++++++++++++++++++++++++
lib/vfscore/Makefile.uk | 5 +++
lib/vfscore/rootfs.c | 97 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 184 insertions(+), 11 deletions(-)
create mode 100644 lib/vfscore/rootfs.c
diff --git a/lib/devfs/Config.uk b/lib/devfs/Config.uk
index e38a616e..6f21c01c 100644
--- a/lib/devfs/Config.uk
+++ b/lib/devfs/Config.uk
@@ -1,10 +1,11 @@
-config LIBDEVFS
+menuconfig LIBDEVFS
bool "devfs: devfs file system"
default n
depends on LIBVFSCORE
+
if LIBDEVFS
- config LIBDEVFS_USE_RAMFS
- bool "Use ramfs as root"
+ config LIBDEVFS_AUTOMOUNT
+ bool "Mount /dev during boot"
+ depends on LIBVFSCORE_AUTOMOUNT_ROOTFS
default n
- select LIBRAMFS
endif
diff --git a/lib/devfs/devfs_vnops.c b/lib/devfs/devfs_vnops.c
index 11a3ea05..d872e622 100644
--- a/lib/devfs/devfs_vnops.c
+++ b/lib/devfs/devfs_vnops.c
@@ -312,15 +312,9 @@ UK_FS_REGISTER(fs_devfs);
__constructor_prio(101) static void devfs_init(void)
{
-#ifdef CONFIG_LIBDEVFS_USE_RAMFS
+#ifdef CONFIG_LIBDEVFS_AUTOMOUNT
int ret;
- ret = mount("", "/", "ramfs", 0, NULL);
- if (ret != 0) {
- uk_pr_debug("Failed to mount / in %s\n", __func__);
- return;
- }
-
ret = mkdir("/dev", S_IRWXU);
if (ret != 0) {
uk_pr_debug("Failed to mkdir /dev in %s\n", __func__);
diff --git a/lib/vfscore/Config.uk b/lib/vfscore/Config.uk
index 5deb7d04..16ffe043 100644
--- a/lib/vfscore/Config.uk
+++ b/lib/vfscore/Config.uk
@@ -13,4 +13,80 @@ config LIBVFSCORE_PIPE_SIZE_ORDER
help
The size of the internal buffer for anonymous pipes is 2^order.
+menuconfig LIBVFSCORE_AUTOMOUNT_ROOTFS
+bool "Automaticaly mount a root filesysytem (/)"
+default n
+help
+ Automatically mounts '/' during boot. If `libuklibparam` is
+ compiled in, the default root filesystem and mount options can
+ be changed with the following library parameters:
+ 'vfs.rootfs', 'vfs.rootdev', 'vfs.rootflags', and 'vfs.rootopts'
+
+if LIBVFSCORE_AUTOMOUNT_ROOTFS
+ choice LIBVFSCORE_ROOTFS
+ prompt "Default root filesystem"
+ default LIBVFSCORE_ROOTFS_RAMFS
+
+ config LIBVFSCORE_ROOTFS_RAMFS
+ bool "RamFS"
+ select LIBRAMFS
+
+ config LIBVFSCORE_ROOTFS_9PFS
+ bool "9PFS"
+ select LIBUK9P
+ select LIB9PFS
+
+ config LIBVFSCORE_ROOTFS_CUSTOM
+ bool "Custom argument"
+ help
+ Please set LIBVFSCORE_ROOTFS_CUSTOM_ARG
+ to a filesystem name that should be used
+ as default.
+ endchoice
+
+ config LIBVFSCORE_ROOTFS_CUSTOM_ARG
+ string "Default custom root filesystem"
+ default ""
+ depends on LIBVFSCORE_ROOTFS_CUSTOM
+ help
+ Custom name of a filesystem to mount (e.g., ramfs,
+ 9pfs). Make sure that the specified filesystem
+ is available for libvfscore.
+
+ # Hidden configuration option that gets automatically filled
+ # with the selected filesystem name
+ config LIBVFSCORE_ROOTFS
+ string
+ default "ramfs" if LIBVFSCORE_ROOTFS_RAMFS
+ default "9pfs" if LIBVFSCORE_ROOTFS_9PFS
+ default LIBVFSCORE_ROOTFS_CUSTOM_ARG if LIBVFSCORE_ROOTFS_CUSTOM
+ default ""
+
+ # The root device option is hidden for RamFS and 9PFS
+ config LIBVFSCORE_ROOTDEV
+ string "Default root device"
+ depends on !LIBVFSCORE_ROOTFS_RAMFS && !LIBVFSCORE_ROOTFS_9PFS
+ default ""
+ help
+ Device to mount the filesystem from. Depending on the
+ selected filesystem, this option may not be required.
+
+ # The root flags is hidden for RamFS
+ config LIBVFSCORE_ROOTFLAGS
+ hex "Default root mount flags"
+ depends on !LIBVFSCORE_ROOTFS_RAMFS
+ default 0x0
+ help
+ Mount flags.
+
+ # The root options are hidden for RamFS
+ config LIBVFSCORE_ROOTOPTS
+ string "Default root mount options"
+ depends on !LIBVFSCORE_ROOTFS_RAMFS
+ default ""
+ help
+ Usually a comma-separated list of additional mount
+ options that are directly interpreted by the target
+ filesystem.
+endif
endif
diff --git a/lib/vfscore/Makefile.uk b/lib/vfscore/Makefile.uk
index 1e5fc114..87269606 100644
--- a/lib/vfscore/Makefile.uk
+++ b/lib/vfscore/Makefile.uk
@@ -1,5 +1,8 @@
$(eval $(call addlib_s,libvfscore,$(CONFIG_LIBVFSCORE)))
+# Register to uklibparam, sets "vfs" as parameter prefix (vfs.*)
+$(eval $(call addlib_paramprefix,libvfscore,vfs))
+
CINCLUDES-y += -I$(LIBVFSCORE_BASE)/include
LIBVFSCORE_CFLAGS-$(call gcc_version_ge,8,0) += -Wno-cast-function-type
@@ -19,6 +22,8 @@ LIBVFSCORE_SRCS-y += $(LIBVFSCORE_BASE)/subr_uio.c
LIBVFSCORE_SRCS-y += $(LIBVFSCORE_BASE)/pipe.c
LIBVFSCORE_PIPE_FLAGS-y += -Wno-cast-function-type
LIBVFSCORE_SRCS-y += $(LIBVFSCORE_BASE)/extra.ld
+LIBVFSCORE_SRCS-$(CONFIG_LIBVFSCORE_AUTOMOUNT_ROOTFS) += \
+ $(LIBVFSCORE_BASE)/rootfs.c
UK_PROVIDED_SYSCALLS-$(CONFIG_LIBVFSCORE) += writev-3
diff --git a/lib/vfscore/rootfs.c b/lib/vfscore/rootfs.c
new file mode 100644
index 00000000..ee3cff80
--- /dev/null
+++ b/lib/vfscore/rootfs.c
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Mount VFS root
+ *
+ * Authors: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
+ *
+ *
+ * Copyright (c) 2019, NEC Laboratories Europe GmbH, NEC Corporation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
the
+ * documentation and/or other materials provided with the
distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived
from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#include <errno.h>
+#include <uk/config.h>
+#include <uk/arch/types.h>
+#include <uk/libparam.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <uk/init.h>
+
+static const char *rootfs = CONFIG_LIBVFSCORE_ROOTFS;
+
+#ifndef CONFIG_LIBVFSCORE_ROOTDEV
+static const char *rootdev = "";
+#else
+static const char *rootdev = CONFIG_LIBVFSCORE_ROOTDEV;
+#endif
+
+#ifndef CONFIG_LIBVFSCORE_ROOTOPTS
+static const char *rootopts = "";
+#else
+static const char *rootopts = CONFIG_LIBVFSCORE_ROOTOPTS;
+#endif
+
+#ifndef CONFIG_LIBVFSCORE_ROOTFLAGS
+static __u64 rootflags = 0x0;
+#else
+static __u64 rootflags = (__u64) CONFIG_LIBVFSCORE_ROOTFLAGS;
+#endif
+
+UK_LIB_PARAM_STR(rootfs);
+UK_LIB_PARAM_STR(rootdev);
+UK_LIB_PARAM_STR(rootopts);
+UK_LIB_PARAM(rootflags, __u64);
+
+static int vfscore_rootfs(void)
+{
+ /*
+ * Initialization of the root filesystem '/'
+ * NOTE: Any additional sub mount points (like '/dev' with devfs)
+ * have to be mounted later.
+ */
+ if (!rootfs || rootfs[0] == '\0') {
+ uk_pr_crit("Parameter 'vfs.rootfs' is invalid\n");
+ return -1;
+ }
+
+ uk_pr_info("Mount %s to /...\n", rootfs);
+ if (mount(rootdev, "/", rootfs, rootflags, rootopts) != 0) {
+ uk_pr_crit("Failed to mount /: %d\n", errno);
+ return -1;
+ }
+
+ /*
+ * TODO: Alternatively we could extract an archive found
+ * as initrd to a ramfs '/' if we have got fsname 'initrd'
+ */
+
+ return 0;
+}
+
+uk_rootfs_initcall_prio(vfscore_rootfs, 0);
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