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authorAl Viro <viro@zeniv.linux.org.uk>2008-03-21 23:59:49 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2008-03-27 20:47:46 -0400
commit7c4b93d8269b9d35971a8239426b1f6ddc3d5ef7 (patch)
treea3309f9237f9d67af000e484bef9c19a7951750a
parent1a39068954e33f4bf3e09375a8112dcc801c4688 (diff)
downloadlinux-linaro-7c4b93d8269b9d35971a8239426b1f6ddc3d5ef7.tar.gz
[PATCH] count ghost references to vfsmounts
make propagate_mount_busy() exclude references from the vfsmounts that had been isolated by umount_tree() and are just waiting for release_mounts() to dispose of their ->mnt_parent/->mnt_mountpoint. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/namespace.c5
-rw-r--r--fs/pnode.c2
-rw-r--r--include/linux/mount.h1
3 files changed, 6 insertions, 2 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 6324dfc80dc..c175218ebae 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -548,6 +548,7 @@ void release_mounts(struct list_head *head)
m = mnt->mnt_parent;
mnt->mnt_mountpoint = mnt->mnt_root;
mnt->mnt_parent = mnt;
+ m->mnt_ghosts--;
spin_unlock(&vfsmount_lock);
dput(dentry);
mntput(m);
@@ -572,8 +573,10 @@ void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
__touch_mnt_namespace(p->mnt_ns);
p->mnt_ns = NULL;
list_del_init(&p->mnt_child);
- if (p->mnt_parent != p)
+ if (p->mnt_parent != p) {
+ p->mnt_parent->mnt_ghosts++;
p->mnt_mountpoint->d_mounted--;
+ }
change_mnt_propagation(p, MS_PRIVATE);
}
}
diff --git a/fs/pnode.c b/fs/pnode.c
index 05ba692bc54..1d8f5447f3f 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -225,7 +225,7 @@ out:
*/
static inline int do_refcount_check(struct vfsmount *mnt, int count)
{
- int mycount = atomic_read(&mnt->mnt_count);
+ int mycount = atomic_read(&mnt->mnt_count) - mnt->mnt_ghosts;
return (mycount > count);
}
diff --git a/include/linux/mount.h b/include/linux/mount.h
index 6d3047d8c91..dac5e67ff3e 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -61,6 +61,7 @@ struct vfsmount {
atomic_t mnt_count;
int mnt_expiry_mark; /* true if marked for expiry */
int mnt_pinned;
+ int mnt_ghosts;
};
static inline struct vfsmount *mntget(struct vfsmount *mnt)