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| author | Al Viro <viro@zeniv.linux.org.uk> | 2008-03-21 23:59:49 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-03-27 20:47:46 -0400 |
| commit | 7c4b93d8269b9d35971a8239426b1f6ddc3d5ef7 (patch) | |
| tree | a3309f9237f9d67af000e484bef9c19a7951750a | |
| parent | 1a39068954e33f4bf3e09375a8112dcc801c4688 (diff) | |
| download | lwn-7c4b93d8269b9d35971a8239426b1f6ddc3d5ef7.tar.gz lwn-7c4b93d8269b9d35971a8239426b1f6ddc3d5ef7.zip | |
[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.c | 5 | ||||
| -rw-r--r-- | fs/pnode.c | 2 | ||||
| -rw-r--r-- | include/linux/mount.h | 1 |
3 files changed, 6 insertions, 2 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 6324dfc80dc6..c175218ebae1 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 05ba692bc540..1d8f5447f3f7 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 6d3047d8c91c..dac5e67ff3ee 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) |