convert ramfs and tmpfs

Quite a bit is already done by infrastructure changes (simple_link(),
simple_unlink()) - all that is left is replacing d_instantiate() +
pinning dget() (in ->symlink() and ->mknod()) with d_make_persistent(),
and, in case of shmem, using simple_unlink() and simple_link() in
->unlink() and ->link() resp., instead of open-coding those there.
Since d_make_persistent() accepts (and hashes) unhashed ones, shmem
situation gets simpler - we no longer care whether ->lookup() has hashed
the sucker.

With that done, we don't need kill_litter_super() for these filesystems
anymore - by the umount time all remaining dentries will be marked
persistent and kill_litter_super() will boil down to call of
kill_anon_super().

The same goes for devtmpfs and rootfs - they are handled by
ramfs or by shmem, depending upon config.

NB: strictly speaking, both devtmpfs and rootfs ought to use
ramfs_kill_sb() if they end up using ramfs; that's a separate
story and the only impact of "just use kill_{litter,anon}_super()"
is that we fail to free their sb->s_fs_info... on reboot.
That's orthogonal to the changes in this series - kill_litter_super()
is identical to kill_anon_super() for those at this point.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 9d4e46ad8352..a63b0ff0c432 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -70,7 +70,7 @@ static struct file_system_type internal_fs_type = {
 #else
 	.init_fs_context = ramfs_init_fs_context,
 #endif
-	.kill_sb = kill_litter_super,
+	.kill_sb = kill_anon_super,
 };
 
 /* Simply take a ref on the existing mount */