From f601f9a2bf7dc1f7ee18feece4c4e2fc6845d6c4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 10 Jan 2014 08:57:23 -0500 Subject: kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove() kernfs_unmap_bin_file() is supposed to unmap all memory mappings of the target file before kernfs_remove() finishes; however, it currently is being called from kernfs_addrm_finish() and has the same race problem as the original implementation of deactivation when there are multiple removers - only the remover which snatches the node to its addrm_cxt->removed list is guaranteed to wait for its completion before returning. It can be fixed by moving kernfs_unmap_bin_file() invocation from kernfs_addrm_finish() to __kernfs_remove(). The function may be called multiple times but that shouldn't do any harm. We end up dropping kernfs_mutex in the removal loop and the node may be removed inbetween by someone else. kernfs_unlink_sibling() is updated to test whether the node has already been removed and return accordingly. __kernfs_remove() in turn performs post-unlinking cleanup only if it actually unlinked the node. KERNFS_HAS_MMAP test is moved out of the unmap function into __kernfs_remove() so that we don't unlock kernfs_mutex unnecessarily. While at it, drop the now meaningless "bin" qualifier from the function name. v2: Rewritten to fit the v2 restructuring of removal path. HAS_MMAP test relocated. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'fs/kernfs/file.c') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 231a171f48b6..404ffd2f27bc 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -700,14 +700,11 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp) return 0; } -void kernfs_unmap_bin_file(struct kernfs_node *kn) +void kernfs_unmap_file(struct kernfs_node *kn) { struct kernfs_open_node *on; struct kernfs_open_file *of; - if (!(kn->flags & KERNFS_HAS_MMAP)) - return; - spin_lock_irq(&kernfs_open_node_lock); on = kn->attr.open; if (on) -- cgit v1.2.3