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Commit c937135d authored by Al Viro's avatar Al Viro
Browse files

vfs: spread struct mount - shared subtree iterators 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 6fc7871f

fs/pnode.c

+47 −50
Original line number Diff line number Diff line
@@ -13,19 +13,19 @@ 
#include "pnode.h"



/* return the next shared peer mount of @p */

static inline struct vfsmount *next_peer(struct vfsmount *p)

static inline struct mount *next_peer(struct mount *p)

{

	return list_entry(p->mnt_share.next, struct vfsmount, mnt_share);

	return list_entry(p->mnt.mnt_share.next, struct mount, mnt.mnt_share);

}



static inline struct vfsmount *first_slave(struct vfsmount *p)

static inline struct mount *first_slave(struct mount *p)

{

	return list_entry(p->mnt_slave_list.next, struct vfsmount, mnt_slave);

	return list_entry(p->mnt.mnt_slave_list.next, struct mount, mnt.mnt_slave);

}



static inline struct vfsmount *next_slave(struct vfsmount *p)

static inline struct mount *next_slave(struct mount *p)

{

	return list_entry(p->mnt_slave.next, struct vfsmount, mnt_slave);

	return list_entry(p->mnt.mnt_slave.next, struct mount, mnt.mnt_slave);

}



static struct mount *get_peer_under_root(struct mount *mnt,
@@ -39,7 +39,7 @@ static struct mount *get_peer_under_root(struct mount *mnt, 
		if (m->mnt.mnt_ns == ns && is_path_reachable(m, m->mnt.mnt_root, root))

			return m;



		m = real_mount(next_peer(&m->mnt));

		m = next_peer(m);

	} while (m != mnt);



	return NULL;
@@ -74,11 +74,11 @@ static int do_make_slave(struct mount *mnt) 
	 * same root dentry. If none is available then

	 * slave it to anything that is available.

	 */

	while ((peer_mnt = real_mount(next_peer(&peer_mnt->mnt))) != mnt &&

	while ((peer_mnt = next_peer(peer_mnt)) != mnt &&

	       peer_mnt->mnt.mnt_root != mnt->mnt.mnt_root) ;



	if (peer_mnt == mnt) {

		peer_mnt = real_mount(next_peer(&mnt->mnt));

		peer_mnt = next_peer(mnt);

		if (peer_mnt == mnt)

			peer_mnt = NULL;

	}
@@ -141,21 +141,20 @@ void change_mnt_propagation(struct mount *mnt, int type) 
 * vfsmount found while iterating with propagation_next() is

 * a peer of one we'd found earlier.

 */

static struct vfsmount *propagation_next(struct vfsmount *m,

					 struct vfsmount *origin)

static struct mount *propagation_next(struct mount *m,

					 struct mount *origin)

{

	/* are there any slaves of this mount? */

	if (!IS_MNT_NEW(m) && !list_empty(&m->mnt_slave_list))

	if (!IS_MNT_NEW(&m->mnt) && !list_empty(&m->mnt.mnt_slave_list))

		return first_slave(m);



	while (1) {

		struct vfsmount *next;

		struct vfsmount *master = m->mnt_master;

		struct mount *master = real_mount(m->mnt.mnt_master);



		if (master == origin->mnt_master) {

			next = next_peer(m);

			return ((next == origin) ? NULL : next);

		} else if (m->mnt_slave.next != &master->mnt_slave_list)

		if (&master->mnt == origin->mnt.mnt_master) {

			struct mount *next = next_peer(m);

			return (next == origin) ? NULL : next;

		} else if (m->mnt.mnt_slave.next != &master->mnt.mnt_slave_list)

			return next_slave(m);



		/* back at master */
@@ -172,25 +171,25 @@ static struct vfsmount *propagation_next(struct vfsmount *m, 
 * @type	return CL_SLAVE if the new mount has to be

 * 		cloned as a slave.

 */

static struct vfsmount *get_source(struct vfsmount *dest,

					struct vfsmount *last_dest,

					struct vfsmount *last_src,

static struct mount *get_source(struct mount *dest,

				struct mount *last_dest,

				struct mount *last_src,

				int *type)

{

	struct vfsmount *p_last_src = NULL;

	struct vfsmount *p_last_dest = NULL;

	struct mount *p_last_src = NULL;

	struct mount *p_last_dest = NULL;



	while (last_dest != dest->mnt_master) {

	while (&last_dest->mnt != dest->mnt.mnt_master) {

		p_last_dest = last_dest;

		p_last_src = last_src;

		last_dest = last_dest->mnt_master;

		last_src = last_src->mnt_master;

		last_dest = real_mount(last_dest->mnt.mnt_master);

		last_src = real_mount(last_src->mnt.mnt_master);

	}



	if (p_last_dest) {

		do {

			p_last_dest = next_peer(p_last_dest);

		} while (IS_MNT_NEW(p_last_dest));

		} while (IS_MNT_NEW(&p_last_dest->mnt));

		/* is that a peer of the earlier? */

		if (dest == p_last_dest) {

			*type = CL_MAKE_SHARED;
@@ -200,7 +199,7 @@ static struct vfsmount *get_source(struct vfsmount *dest, 
	/* slave of the earlier, then */

	*type = CL_SLAVE;

	/* beginning of peer group among the slaves? */

	if (IS_MNT_SHARED(dest))

	if (IS_MNT_SHARED(&dest->mnt))

		*type |= CL_MAKE_SHARED;

	return last_src;

}
@@ -221,32 +220,31 @@ static struct vfsmount *get_source(struct vfsmount *dest, 
int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry,

		    struct vfsmount *source_mnt, struct list_head *tree_list)

{

	struct vfsmount *m;

	struct mount *child;

	struct mount *m, *child;

	int ret = 0;

	struct vfsmount *prev_dest_mnt = dest_mnt;

	struct vfsmount *prev_src_mnt  = source_mnt;

	struct mount *prev_dest_mnt = real_mount(dest_mnt);

	struct mount *prev_src_mnt  = real_mount(source_mnt);

	LIST_HEAD(tmp_list);

	LIST_HEAD(umount_list);



	for (m = propagation_next(dest_mnt, dest_mnt); m;

			m = propagation_next(m, dest_mnt)) {

	for (m = propagation_next(real_mount(dest_mnt), real_mount(dest_mnt)); m;

			m = propagation_next(m, real_mount(dest_mnt))) {

		int type;

		struct vfsmount *source;

		struct mount *source;



		if (IS_MNT_NEW(m))

		if (IS_MNT_NEW(&m->mnt))

			continue;



		source =  get_source(m, prev_dest_mnt, prev_src_mnt, &type);



		if (!(child = copy_tree(real_mount(source), source->mnt_root, type))) {

		if (!(child = copy_tree(source, source->mnt.mnt_root, type))) {

			ret = -ENOMEM;

			list_splice(tree_list, tmp_list.prev);

			goto out;

		}



		if (is_subdir(dest_dentry, m->mnt_root)) {

			mnt_set_mountpoint(m, dest_dentry, child);

		if (is_subdir(dest_dentry, m->mnt.mnt_root)) {

			mnt_set_mountpoint(&m->mnt, dest_dentry, child);

			list_add_tail(&child->mnt_hash, tree_list);

		} else {

			/*
@@ -256,7 +254,7 @@ int propagate_mnt(struct vfsmount *dest_mnt, struct dentry *dest_dentry, 
			list_add_tail(&child->mnt_hash, &tmp_list);

		}

		prev_dest_mnt = m;

		prev_src_mnt  = &child->mnt;

		prev_src_mnt  = child;

	}

out:

	br_write_lock(vfsmount_lock);
@@ -290,8 +288,7 @@ static inline int do_refcount_check(struct mount *mnt, int count) 
 */

int propagate_mount_busy(struct mount *mnt, int refcnt)

{

	struct vfsmount *m;

	struct mount *child;

	struct mount *m, *child;

	struct mount *parent = mnt->mnt_parent;

	int ret = 0;
@@ -306,9 +303,9 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 
	if (!list_empty(&mnt->mnt_mounts) || do_refcount_check(mnt, refcnt))

		return 1;



	for (m = propagation_next(&parent->mnt, &parent->mnt); m;

	     		m = propagation_next(m, &parent->mnt)) {

		child = __lookup_mnt(m, mnt->mnt_mountpoint, 0);

	for (m = propagation_next(parent, parent); m;

	     		m = propagation_next(m, parent)) {

		child = __lookup_mnt(&m->mnt, mnt->mnt_mountpoint, 0);

		if (child && list_empty(&child->mnt_mounts) &&

		    (ret = do_refcount_check(child, 1)))

			break;
@@ -323,14 +320,14 @@ int propagate_mount_busy(struct mount *mnt, int refcnt) 
static void __propagate_umount(struct mount *mnt)

{

	struct mount *parent = mnt->mnt_parent;

	struct vfsmount *m;

	struct mount *m;



	BUG_ON(parent == mnt);



	for (m = propagation_next(&parent->mnt, &parent->mnt); m;

			m = propagation_next(m, &parent->mnt)) {

	for (m = propagation_next(parent, parent); m;

			m = propagation_next(m, parent)) {



		struct mount *child = __lookup_mnt(m,

		struct mount *child = __lookup_mnt(&m->mnt,

					mnt->mnt_mountpoint, 0);

		/*

		 * umount the child only if the child has no