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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 12:38:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 12:38:18 -0700
commite2e694b9e6f3ec7deeb233b6b0fe20b6a47b304b (patch)
treef98682de600e9b224f73412d855f5a40f635b5ca /init/do_mounts.c
parent7b7699c09f66f180b9a8a5010df352acb8683bfa (diff)
parent6e7c1770a212239e88ec01ddc7a741505bfd10e5 (diff)
Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull root filesystem type handling updates from Al Viro: "Teach init/do_mounts.c to handle non-block filesystems, hopefully preventing even more special-cased kludges (such as root=/dev/nfs, etc)" * 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: simplify get_filesystem_list / get_all_fs_names init: allow mounting arbitrary non-blockdevice filesystems as root init: split get_fs_names
Diffstat (limited to 'init/do_mounts.c')
-rw-r--r--init/do_mounts.c90
1 files changed, 65 insertions, 25 deletions
diff --git a/init/do_mounts.c b/init/do_mounts.c
index b691d6891e51..2ed30ff6c906 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -338,31 +338,22 @@ __setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);
-static void __init get_fs_names(char *page)
+static int __init split_fs_names(char *page, char *names)
{
- char *s = page;
+ int count = 0;
+ char *p = page;
- if (root_fs_names) {
- strcpy(page, root_fs_names);
- while (*s++) {
- if (s[-1] == ',')
- s[-1] = '\0';
- }
- } else {
- int len = get_filesystem_list(page);
- char *p, *next;
-
- page[len] = '\0';
- for (p = page-1; p; p = next) {
- next = strchr(++p, '\n');
- if (*p++ != '\t')
- continue;
- while ((*s++ = *p++) != '\n')
- ;
- s[-1] = '\0';
- }
+ strcpy(p, root_fs_names);
+ while (*p++) {
+ if (p[-1] == ',')
+ p[-1] = '\0';
}
- *s = '\0';
+ *p = '\0';
+
+ for (p = page; *p; p += strlen(p)+1)
+ count++;
+
+ return count;
}
static int __init do_mount_root(const char *name, const char *fs,
@@ -408,12 +399,16 @@ void __init mount_block_root(char *name, int flags)
char *fs_names = page_address(page);
char *p;
char b[BDEVNAME_SIZE];
+ int num_fs, i;
scnprintf(b, BDEVNAME_SIZE, "unknown-block(%u,%u)",
MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
- get_fs_names(fs_names);
+ if (root_fs_names)
+ num_fs = split_fs_names(fs_names, root_fs_names);
+ else
+ num_fs = list_bdev_fs_names(fs_names, PAGE_SIZE);
retry:
- for (p = fs_names; *p; p += strlen(p)+1) {
+ for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1) {
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
@@ -442,7 +437,7 @@ retry:
printk("List of all partitions:\n");
printk_all_partitions();
printk("No filesystem could mount root, tried: ");
- for (p = fs_names; *p; p += strlen(p)+1)
+ for (i = 0, p = fs_names; i < num_fs; i++, p += strlen(p)+1)
printk(" %s", p);
printk("\n");
panic("VFS: Unable to mount root fs on %s", b);
@@ -526,6 +521,47 @@ static int __init mount_cifs_root(void)
}
#endif
+static bool __init fs_is_nodev(char *fstype)
+{
+ struct file_system_type *fs = get_fs_type(fstype);
+ bool ret = false;
+
+ if (fs) {
+ ret = !(fs->fs_flags & FS_REQUIRES_DEV);
+ put_filesystem(fs);
+ }
+
+ return ret;
+}
+
+static int __init mount_nodev_root(void)
+{
+ char *fs_names, *fstype;
+ int err = -EINVAL;
+ int num_fs, i;
+
+ fs_names = (void *)__get_free_page(GFP_KERNEL);
+ if (!fs_names)
+ return -EINVAL;
+ num_fs = split_fs_names(fs_names, root_fs_names);
+
+ for (i = 0, fstype = fs_names; i < num_fs;
+ i++, fstype += strlen(fstype) + 1) {
+ if (!fs_is_nodev(fstype))
+ continue;
+ err = do_mount_root(root_device_name, fstype, root_mountflags,
+ root_mount_data);
+ if (!err)
+ break;
+ if (err != -EACCES && err != -EINVAL)
+ panic("VFS: Unable to mount root \"%s\" (%s), err=%d\n",
+ root_device_name, fstype, err);
+ }
+
+ free_page((unsigned long)fs_names);
+ return err;
+}
+
void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
@@ -542,6 +578,10 @@ void __init mount_root(void)
return;
}
#endif
+ if (ROOT_DEV == 0 && root_device_name && root_fs_names) {
+ if (mount_nodev_root() == 0)
+ return;
+ }
#ifdef CONFIG_BLOCK
{
int err = create_dev("/dev/root", ROOT_DEV);