On Fri, 2008-11-28 at 10:53 +0000, Al Viro wrote:

quoted

+static int cr_ctx_checkpoint(struct cr_ctx *ctx, pid_t pid)
+{
+     ctx->root_pid = pid;
+
+     /*
+      * assume checkpointer is in container's root vfs
+      * FIXME: this works for now, but will change with real containers
+      */
+     ctx->vfsroot = &current->fs->root;
+     path_get(ctx->vfsroot);

This is going to break as soon as you get another thread doing e.g. chroot(2)
while you are in there.

Yeah, we do need at least a read_lock(&current->fs->lock) to keep people
from chroot()'ing underneath us.

And it's a really, _really_ bad idea to take a
pointer to shared object, increment refcount on the current *contents* of
said object and assume that dropping refcount on the later contents of the
same will balance out.

Absolutely.  I assume you mean get_fs_struct(current) instead of
path_get().

-- Dave

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