vfs: spread struct mount - shared subtree iterators

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2011-11-24 23:56:26 -05:00
parent 6fc7871fed
commit c937135d98

View file

@ -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,
int *type)
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