From 0714a533805a0f8ebfc6fdb6bda9f129b8c7c6d7 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 24 Nov 2011 22:19:58 -0500 Subject: vfs: now it can be done - make mnt_parent point to struct mount Signed-off-by: Al Viro --- fs/dcache.c | 7 ++++--- fs/mount.h | 4 ++-- fs/namei.c | 24 +++++++++++++----------- fs/namespace.c | 52 ++++++++++++++++++++++++++-------------------------- fs/pnode.c | 16 ++++++++-------- 5 files changed, 53 insertions(+), 50 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index eef2d5472f9c..98b48753f77b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2452,6 +2452,7 @@ static int prepend_path(const struct path *path, { struct dentry *dentry = path->dentry; struct vfsmount *vfsmnt = path->mnt; + struct mount *mnt = real_mount(vfsmnt); bool slash = false; int error = 0; @@ -2460,12 +2461,12 @@ static int prepend_path(const struct path *path, struct dentry * parent; if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { - struct mount *mnt = real_mount(vfsmnt); /* Global root? */ if (!mnt_has_parent(mnt)) goto global_root; - dentry = vfsmnt->mnt_mountpoint; - vfsmnt = mnt->mnt_parent; + dentry = mnt->mnt.mnt_mountpoint; + mnt = mnt->mnt_parent; + vfsmnt = &mnt->mnt; continue; } parent = dentry->d_parent; diff --git a/fs/mount.h b/fs/mount.h index 5126c0861102..201dd616e6c4 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -2,7 +2,7 @@ struct mount { struct list_head mnt_hash; - struct vfsmount *mnt_parent; + struct mount *mnt_parent; struct vfsmount mnt; }; @@ -13,7 +13,7 @@ static inline struct mount *real_mount(struct vfsmount *mnt) static inline int mnt_has_parent(struct mount *mnt) { - return &mnt->mnt != mnt->mnt_parent; + return mnt != mnt->mnt_parent; } extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int); diff --git a/fs/namei.c b/fs/namei.c index 89248bf1b906..2e9110a37c0e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -677,36 +677,38 @@ follow_link(struct path *link, struct nameidata *nd, void **p) static int follow_up_rcu(struct path *path) { - struct vfsmount *parent; + struct mount *mnt = real_mount(path->mnt); + struct mount *parent; struct dentry *mountpoint; - parent = real_mount(path->mnt)->mnt_parent; - if (parent == path->mnt) + parent = mnt->mnt_parent; + if (&parent->mnt == path->mnt) return 0; - mountpoint = path->mnt->mnt_mountpoint; + mountpoint = mnt->mnt.mnt_mountpoint; path->dentry = mountpoint; - path->mnt = parent; + path->mnt = &parent->mnt; return 1; } int follow_up(struct path *path) { - struct vfsmount *parent; + struct mount *mnt = real_mount(path->mnt); + struct mount *parent; struct dentry *mountpoint; br_read_lock(vfsmount_lock); - parent = real_mount(path->mnt)->mnt_parent; - if (parent == path->mnt) { + parent = mnt->mnt_parent; + if (&parent->mnt == path->mnt) { br_read_unlock(vfsmount_lock); return 0; } - mntget(parent); - mountpoint = dget(path->mnt->mnt_mountpoint); + mntget(&parent->mnt); + mountpoint = dget(mnt->mnt.mnt_mountpoint); br_read_unlock(vfsmount_lock); dput(path->dentry); path->dentry = mountpoint; mntput(path->mnt); - path->mnt = parent; + path->mnt = &parent->mnt; return 1; } diff --git a/fs/namespace.c b/fs/namespace.c index c6384bc39db1..5e700c6df579 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -476,7 +476,7 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry, if (tmp == head) break; p = list_entry(tmp, struct mount, mnt_hash); - if (p->mnt_parent == mnt && p->mnt.mnt_mountpoint == dentry) { + if (&p->mnt_parent->mnt == mnt && p->mnt.mnt_mountpoint == dentry) { found = p; break; } @@ -558,8 +558,8 @@ static void dentry_reset_mounted(struct dentry *dentry) static void detach_mnt(struct mount *mnt, struct path *old_path) { old_path->dentry = mnt->mnt.mnt_mountpoint; - old_path->mnt = mnt->mnt_parent; - mnt->mnt_parent = &mnt->mnt; + old_path->mnt = &mnt->mnt_parent->mnt; + mnt->mnt_parent = mnt; mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root; list_del_init(&mnt->mnt.mnt_child); list_del_init(&mnt->mnt_hash); @@ -572,7 +572,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path) void mnt_set_mountpoint(struct vfsmount *mnt, struct dentry *dentry, struct mount *child_mnt) { - child_mnt->mnt_parent = mntget(mnt); + child_mnt->mnt_parent = real_mount(mntget(mnt)); child_mnt->mnt.mnt_mountpoint = dget(dentry); spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_MOUNTED; @@ -610,12 +610,12 @@ static inline void __mnt_make_shortterm(struct vfsmount *mnt) */ static void commit_tree(struct mount *mnt) { - struct vfsmount *parent = mnt->mnt_parent; + struct mount *parent = mnt->mnt_parent; struct vfsmount *m; LIST_HEAD(head); - struct mnt_namespace *n = parent->mnt_ns; + struct mnt_namespace *n = parent->mnt.mnt_ns; - BUG_ON(parent == &mnt->mnt); + BUG_ON(parent == mnt); list_add_tail(&head, &mnt->mnt.mnt_list); list_for_each_entry(m, &head, mnt_list) { @@ -626,8 +626,8 @@ static void commit_tree(struct mount *mnt) list_splice(&head, n->list.prev); list_add_tail(&mnt->mnt_hash, mount_hashtable + - hash(parent, mnt->mnt.mnt_mountpoint)); - list_add_tail(&mnt->mnt.mnt_child, &parent->mnt_mounts); + hash(&parent->mnt, mnt->mnt.mnt_mountpoint)); + list_add_tail(&mnt->mnt.mnt_child, &parent->mnt.mnt_mounts); touch_mnt_namespace(n); } @@ -639,9 +639,9 @@ static struct mount *next_mnt(struct mount *p, struct vfsmount *root) if (&p->mnt == root) return NULL; next = p->mnt.mnt_child.next; - if (next != &p->mnt_parent->mnt_mounts) + if (next != &p->mnt_parent->mnt.mnt_mounts) break; - p = real_mount(p->mnt_parent); + p = p->mnt_parent; } } return list_entry(next, struct mount, mnt.mnt_child); @@ -682,7 +682,7 @@ vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void mnt->mnt.mnt_root = root; mnt->mnt.mnt_sb = root->d_sb; mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root; - mnt->mnt_parent = &mnt->mnt; + mnt->mnt_parent = mnt; return &mnt->mnt; } EXPORT_SYMBOL_GPL(vfs_kern_mount); @@ -710,7 +710,7 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, mnt->mnt.mnt_sb = sb; mnt->mnt.mnt_root = dget(root); mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root; - mnt->mnt_parent = &mnt->mnt; + mnt->mnt_parent = mnt; if (flag & CL_SLAVE) { list_add(&mnt->mnt.mnt_slave, &old->mnt.mnt_slave_list); @@ -1027,7 +1027,7 @@ static int show_mountinfo(struct seq_file *m, void *v) struct path root = p->root; int err = 0; - seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, r->mnt_parent->mnt_id, + seq_printf(m, "%i %i %u:%u ", mnt->mnt_id, r->mnt_parent->mnt.mnt_id, MAJOR(sb->s_dev), MINOR(sb->s_dev)); if (sb->s_op->show_path) err = sb->s_op->show_path(m, mnt); @@ -1202,9 +1202,9 @@ void release_mounts(struct list_head *head) br_write_lock(vfsmount_lock); dentry = mnt->mnt.mnt_mountpoint; - m = mnt->mnt_parent; + m = &mnt->mnt_parent->mnt; mnt->mnt.mnt_mountpoint = mnt->mnt.mnt_root; - mnt->mnt_parent = &mnt->mnt; + mnt->mnt_parent = mnt; m->mnt_ghosts--; br_write_unlock(vfsmount_lock); dput(dentry); @@ -1237,7 +1237,7 @@ void umount_tree(struct mount *mnt, int propagate, struct list_head *kill) __mnt_make_shortterm(&p->mnt); list_del_init(&p->mnt.mnt_child); if (mnt_has_parent(p)) { - p->mnt_parent->mnt_ghosts++; + p->mnt_parent->mnt.mnt_ghosts++; dentry_reset_mounted(p->mnt.mnt_mountpoint); } change_mnt_propagation(p, MS_PRIVATE); @@ -1435,9 +1435,9 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, s = skip_mnt_tree(s); continue; } - while (p != real_mount(s->mnt_parent)) { - p = real_mount(p->mnt_parent); - q = real_mount(q->mnt_parent); + while (p != s->mnt_parent) { + p = p->mnt_parent; + q = q->mnt_parent; } p = s; path.mnt = &q->mnt; @@ -1899,7 +1899,7 @@ static int do_move_mount(struct path *path, char *old_name) /* * Don't move a mount residing in a shared parent. */ - if (IS_MNT_SHARED(old->mnt_parent)) + if (IS_MNT_SHARED(&old->mnt_parent->mnt)) goto out1; /* * Don't move a mount tree containing unbindable mounts to a destination @@ -1909,7 +1909,7 @@ static int do_move_mount(struct path *path, char *old_name) tree_contains_unbindable(old)) goto out1; err = -ELOOP; - for (p = real_mount(path->mnt); mnt_has_parent(p); p = real_mount(p->mnt_parent)) + for (p = real_mount(path->mnt); mnt_has_parent(p); p = p->mnt_parent) if (p == old) goto out1; @@ -2159,7 +2159,7 @@ resume: */ if (this_parent != parent) { next = this_parent->mnt.mnt_child.next; - this_parent = real_mount(this_parent->mnt_parent); + this_parent = this_parent->mnt_parent; goto resume; } return found; @@ -2565,7 +2565,7 @@ bool is_path_reachable(struct mount *mnt, struct dentry *dentry, { while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) { dentry = mnt->mnt.mnt_mountpoint; - mnt = real_mount(mnt->mnt_parent); + mnt = mnt->mnt_parent; } return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry); } @@ -2636,8 +2636,8 @@ SYSCALL_DEFINE2(pivot_root, const char __user *, new_root, new_mnt = real_mount(new.mnt); root_mnt = real_mount(root.mnt); if (IS_MNT_SHARED(old.mnt) || - IS_MNT_SHARED(new_mnt->mnt_parent) || - IS_MNT_SHARED(root_mnt->mnt_parent)) + IS_MNT_SHARED(&new_mnt->mnt_parent->mnt) || + IS_MNT_SHARED(&root_mnt->mnt_parent->mnt)) goto out4; if (!check_mnt(root.mnt) || !check_mnt(new.mnt)) goto out4; diff --git a/fs/pnode.c b/fs/pnode.c index 2ff4dfa018e1..7fddc671f729 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -292,10 +292,10 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) { struct vfsmount *m; struct mount *child; - struct vfsmount *parent = mnt->mnt_parent; + struct mount *parent = mnt->mnt_parent; int ret = 0; - if (&mnt->mnt == parent) + if (mnt == parent) return do_refcount_check(mnt, refcnt); /* @@ -306,8 +306,8 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) if (!list_empty(&mnt->mnt.mnt_mounts) || do_refcount_check(mnt, refcnt)) return 1; - for (m = propagation_next(parent, parent); m; - m = propagation_next(m, parent)) { + for (m = propagation_next(&parent->mnt, &parent->mnt); m; + m = propagation_next(m, &parent->mnt)) { child = __lookup_mnt(m, mnt->mnt.mnt_mountpoint, 0); if (child && list_empty(&child->mnt.mnt_mounts) && (ret = do_refcount_check(child, 1))) @@ -322,13 +322,13 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) */ static void __propagate_umount(struct mount *mnt) { - struct vfsmount *parent = mnt->mnt_parent; + struct mount *parent = mnt->mnt_parent; struct vfsmount *m; - BUG_ON(parent == &mnt->mnt); + BUG_ON(parent == mnt); - for (m = propagation_next(parent, parent); m; - m = propagation_next(m, parent)) { + for (m = propagation_next(&parent->mnt, &parent->mnt); m; + m = propagation_next(m, &parent->mnt)) { struct mount *child = __lookup_mnt(m, mnt->mnt.mnt_mountpoint, 0); -- cgit