From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/init/do_mounts.c | 212 ++++++++++++++++++++++++++++------------------------
1 files changed, 115 insertions(+), 97 deletions(-)
diff --git a/kernel/init/do_mounts.c b/kernel/init/do_mounts.c
index e1c9afa..b5f9604 100644
--- a/kernel/init/do_mounts.c
+++ b/kernel/init/do_mounts.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
@@ -22,10 +23,10 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>
+#include <linux/raid/detect.h>
+#include <uapi/linux/mount.h>
#include "do_mounts.h"
-
-int __initdata rd_doload; /* 1 = load RAM disk, 0 = don't load */
int root_mountflags = MS_RDONLY | MS_SILENT;
static char * __initdata root_device_name;
@@ -36,7 +37,7 @@
static int __init load_ramdisk(char *str)
{
- rd_doload = simple_strtol(str,NULL,0) & 3;
+ pr_warn("ignoring the deprecated load_ramdisk= option\n");
return 1;
}
__setup("load_ramdisk=", load_ramdisk);
@@ -167,6 +168,24 @@
}
return res;
}
+
+/**
+ * match_dev_by_label - callback for finding a partition using its label
+ * @dev: device passed in by the caller
+ * @data: opaque pointer to the label to match
+ *
+ * Returns 1 if the device matches, and 0 otherwise.
+ */
+static int match_dev_by_label(struct device *dev, const void *data)
+{
+ const char *label = data;
+ struct hd_struct *part = dev_to_part(dev);
+
+ if (part->info && !strcmp(label, part->info->volname))
+ return 1;
+
+ return 0;
+}
#endif
/*
@@ -190,6 +209,9 @@
* a partition with a known unique id.
* 8) <major>:<minor> major and minor number of the device separated by
* a colon.
+ * 9) PARTLABEL=<name> with name being the GPT partition label.
+ * MSDOS partitions do not support labels!
+ * 10) /dev/cifs represents Root_CIFS (0xfe)
*
* If name doesn't have fall into the categories above, we return (0,0).
* block_class is used to check if something is a disk name. If the disk
@@ -210,6 +232,17 @@
res = devt_from_partuuid(name);
if (!res)
goto fail;
+ goto done;
+ } else if (strncmp(name, "PARTLABEL=", 10) == 0) {
+ struct device *dev;
+
+ dev = class_find_device(&block_class, NULL, name + 10,
+ &match_dev_by_label);
+ if (!dev)
+ goto fail;
+
+ res = dev->devt;
+ put_device(dev);
goto done;
}
#endif
@@ -234,6 +267,9 @@
name += 5;
res = Root_NFS;
if (strcmp(name, "nfs") == 0)
+ goto done;
+ res = Root_CIFS;
+ if (strcmp(name, "cifs") == 0)
goto done;
res = Root_RAM0;
if (strcmp(name, "ram") == 0)
@@ -350,14 +386,29 @@
*s = '\0';
}
-static int __init do_mount_root(char *name, char *fs, int flags, void *data)
+static int __init do_mount_root(const char *name, const char *fs,
+ const int flags, const void *data)
{
struct super_block *s;
- int err = ksys_mount(name, "/root", fs, flags, data);
- if (err)
- return err;
+ struct page *p = NULL;
+ char *data_page = NULL;
+ int ret;
- ksys_chdir("/root");
+ if (data) {
+ /* init_mount() requires a full page as fifth argument */
+ p = alloc_page(GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+ data_page = page_address(p);
+ /* zero-pad. init_mount() will make sure it's terminated */
+ strncpy(data_page, data, PAGE_SIZE);
+ }
+
+ ret = init_mount(name, "/root", fs, flags, data_page);
+ if (ret)
+ goto out;
+
+ init_chdir("/root");
s = current->fs->pwd.dentry->d_sb;
ROOT_DEV = s->s_dev;
printk(KERN_INFO
@@ -365,7 +416,11 @@
s->s_type->name,
sb_rdonly(s) ? " readonly" : "",
MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
- return 0;
+
+out:
+ if (p)
+ put_page(p);
+ return ret;
}
void __init mount_block_root(char *name, int flags)
@@ -373,12 +428,10 @@
struct page *page = alloc_page(GFP_KERNEL);
char *fs_names = page_address(page);
char *p;
-#ifdef CONFIG_BLOCK
char b[BDEVNAME_SIZE];
-#else
- const char *b = name;
-#endif
+ scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
+ MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
get_fs_names(fs_names);
retry:
for (p = fs_names; *p; p += strlen(p)+1) {
@@ -395,9 +448,6 @@
* and bad superblock on root device.
* and give them a list of the available devices
*/
-#ifdef CONFIG_BLOCK
- __bdevname(ROOT_DEV, b);
-#endif
printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
root_device_name, b, err);
printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
@@ -420,9 +470,6 @@
for (p = fs_names; *p; p += strlen(p)+1)
printk(" %s", p);
printk("\n");
-#ifdef CONFIG_BLOCK
- __bdevname(ROOT_DEV, b);
-#endif
panic("VFS: Unable to mount root fs on %s", b);
out:
put_page(page);
@@ -468,33 +515,39 @@
}
#endif
-#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
-void __init change_floppy(char *fmt, ...)
+#ifdef CONFIG_CIFS_ROOT
+
+extern int cifs_root_data(char **dev, char **opts);
+
+#define CIFSROOT_TIMEOUT_MIN 5
+#define CIFSROOT_TIMEOUT_MAX 30
+#define CIFSROOT_RETRY_MAX 5
+
+static int __init mount_cifs_root(void)
{
- struct termios termios;
- char buf[80];
- char c;
- int fd;
- va_list args;
- va_start(args, fmt);
- vsprintf(buf, fmt, args);
- va_end(args);
- fd = ksys_open("/dev/root", O_RDWR | O_NDELAY, 0);
- if (fd >= 0) {
- ksys_ioctl(fd, FDEJECT, 0);
- ksys_close(fd);
+ char *root_dev, *root_data;
+ unsigned int timeout;
+ int try, err;
+
+ err = cifs_root_data(&root_dev, &root_data);
+ if (err != 0)
+ return 0;
+
+ timeout = CIFSROOT_TIMEOUT_MIN;
+ for (try = 1; ; try++) {
+ err = do_mount_root(root_dev, "cifs", root_mountflags,
+ root_data);
+ if (err == 0)
+ return 1;
+ if (try > CIFSROOT_RETRY_MAX)
+ break;
+
+ ssleep(timeout);
+ timeout <<= 1;
+ if (timeout > CIFSROOT_TIMEOUT_MAX)
+ timeout = CIFSROOT_TIMEOUT_MAX;
}
- printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
- fd = ksys_open("/dev/console", O_RDWR, 0);
- if (fd >= 0) {
- ksys_ioctl(fd, TCGETS, (long)&termios);
- termios.c_lflag &= ~ICANON;
- ksys_ioctl(fd, TCSETSF, (long)&termios);
- ksys_read(fd, &c, 1);
- termios.c_lflag |= ICANON;
- ksys_ioctl(fd, TCSETSF, (long)&termios);
- ksys_close(fd);
- }
+ return 0;
}
#endif
@@ -502,23 +555,16 @@
{
#ifdef CONFIG_ROOT_NFS
if (ROOT_DEV == Root_NFS) {
- if (mount_nfs_root())
- return;
-
- printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
- ROOT_DEV = Root_FD0;
+ if (!mount_nfs_root())
+ printk(KERN_ERR "VFS: Unable to mount root fs via NFS.\n");
+ return;
}
#endif
-#ifdef CONFIG_BLK_DEV_FD
- if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
- /* rd_doload is 2 for a dual initrd/ramload setup */
- if (rd_doload==2) {
- if (rd_load_disk(1)) {
- ROOT_DEV = Root_RAM1;
- root_device_name = NULL;
- }
- } else
- change_floppy("root floppy");
+#ifdef CONFIG_CIFS_ROOT
+ if (ROOT_DEV == Root_CIFS) {
+ if (!mount_cifs_root())
+ printk(KERN_ERR "VFS: Unable to mount root fs via SMB.\n");
+ return;
}
#endif
#ifdef CONFIG_BLOCK
@@ -537,8 +583,6 @@
*/
void __init prepare_namespace(void)
{
- int is_floppy;
-
if (root_delay) {
printk(KERN_INFO "Waiting %d sec before mounting root device...\n",
root_delay);
@@ -581,57 +625,31 @@
async_synchronize_full();
}
- is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
-
- if (is_floppy && rd_doload && rd_load_disk(0))
- ROOT_DEV = Root_RAM0;
-
mount_root();
out:
- devtmpfs_mount("dev");
- ksys_mount(".", "/", NULL, MS_MOVE, NULL);
- ksys_chroot(".");
+ devtmpfs_mount();
+ init_mount(".", "/", NULL, MS_MOVE, NULL);
+ init_chroot(".");
}
static bool is_tmpfs;
-static struct dentry *rootfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int rootfs_init_fs_context(struct fs_context *fc)
{
- static unsigned long once;
- void *fill = ramfs_fill_super;
-
- if (test_and_set_bit(0, &once))
- return ERR_PTR(-ENODEV);
-
if (IS_ENABLED(CONFIG_TMPFS) && is_tmpfs)
- fill = shmem_fill_super;
+ return shmem_init_fs_context(fc);
- return mount_nodev(fs_type, flags, data, fill);
+ return ramfs_init_fs_context(fc);
}
-static struct file_system_type rootfs_fs_type = {
+struct file_system_type rootfs_fs_type = {
.name = "rootfs",
- .mount = rootfs_mount,
+ .init_fs_context = rootfs_init_fs_context,
.kill_sb = kill_litter_super,
};
-int __init init_rootfs(void)
+void __init init_rootfs(void)
{
- int err = register_filesystem(&rootfs_fs_type);
-
- if (err)
- return err;
-
if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
- (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
- err = shmem_init();
+ (!root_fs_names || strstr(root_fs_names, "tmpfs")))
is_tmpfs = true;
- } else {
- err = init_ramfs_fs();
- }
-
- if (err)
- unregister_filesystem(&rootfs_fs_type);
-
- return err;
}
--
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