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authorTejun Heo <tj@kernel.org>2014-01-10 08:57:23 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-10 13:48:08 -0800
commitf601f9a2bf7dc1f7ee18feece4c4e2fc6845d6c4 (patch)
treef8213b3d7542c85c42cb1a20668098609d65762c /fs/kernfs/file.c
parent45a140e587f3d32d8d424ed940dffb61e1739047 (diff)
downloadlinux-f601f9a2bf7dc1f7ee18feece4c4e2fc6845d6c4.tar.bz2
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 <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/kernfs/file.c')
-rw-r--r--fs/kernfs/file.c5
1 files changed, 1 insertions, 4 deletions
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)