vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API

Convert the ramfs, shmem, tmpfs, devtmpfs and rootfs filesystems to the new
internal mount API as the old one will be obsoleted and removed.  This
allows greater flexibility in communication of mount parameters between
userspace, the VFS and the filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Note that tmpfs is slightly tricky as it can contain embedded commas, so it
can't be trivially split up using strsep() to break on commas in
generic_parse_monolithic().  Instead, tmpfs has to supply its own generic
parser.

However, if tmpfs changes, then devtmpfs and rootfs, which are wrappers
around tmpfs or ramfs, must change too - and thus so must ramfs, so these
had to be converted also.

[AV: rewritten]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hugh Dickins <hughd@google.com>
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 10 deletions

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index dabf5006a254..30d0523014e0 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -67,19 +67,15 @@ static struct dentry *public_dev_mount(struct file_system_type *fs_type, int fla
 	return dget(s->s_root);
 }
 
-static struct dentry *dev_mount(struct file_system_type *fs_type, int flags,
-		      const char *dev_name, void *data)
-{
+static struct file_system_type internal_fs_type = {
+	.name = "devtmpfs",
 #ifdef CONFIG_TMPFS
-	return shmem_mount(fs_type, flags, dev_name, data);
+	.init_fs_context = shmem_init_fs_context,
+	.parameters	= &shmem_fs_parameters,
 #else
-	return ramfs_mount(fs_type, flags, dev_name, data);
+	.init_fs_context = ramfs_init_fs_context,
+	.parameters	= &ramfs_fs_parameters,
 #endif
-}
-
-static struct file_system_type internal_fs_type = {
-	.name = "devtmpfs",
-	.mount = dev_mount,
 	.kill_sb = kill_litter_super,
 };