[Devel] [PATCH VZ10 2/8] ve/mount: thread owning ve through alloc_vfsmnt/clone_mnt/copy_tree
Pavel Tikhomirov
ptikhomirov at virtuozzo.com
Wed Apr 29 16:41:36 MSK 2026
Add owner_ve parameter to alloc_vfsmnt(), clone_mnt() and copy_tree(),
to identify correct ownership of mount for accounting. NULL preserves
the existing behaviour of taking current ve via get_exec_env().
This will be used to derive correct ownership of newly created mounts in
case of simultaneous creation of new ve namespace and mount namespace,
were we would like new mounts to have the new ve as an owner.
There is no change in behaviour yet: copy_mnt_ns() still resolves the
owner from current ve via get_exec_env().
https://virtuozzo.atlassian.net/browse/VSTOR-129744
Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
Feature: ve: ve generic structures
---
fs/namespace.c | 43 +++++++++++++++++++++++++------------------
fs/pnode.c | 2 +-
fs/pnode.h | 5 ++++-
3 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index dd10ed5007ea..ba2cee9a6db1 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -308,10 +308,10 @@ int mnt_get_count(struct mount *mnt)
}
static inline int ve_mount_allowed(void);
-static inline void ve_mount_nr_inc(struct mount *mnt);
+static inline void ve_mount_nr_inc(struct mount *mnt, struct ve_struct *ve);
static inline void ve_mount_nr_dec(struct mount *mnt);
-static struct mount *alloc_vfsmnt(const char *name)
+static struct mount *alloc_vfsmnt(const char *name, struct ve_struct *owner_ve)
{
struct mount *mnt;
@@ -360,7 +360,7 @@ static struct mount *alloc_vfsmnt(const char *name)
INIT_LIST_HEAD(&mnt->mnt_umounting);
INIT_HLIST_HEAD(&mnt->mnt_stuck_children);
mnt->mnt.mnt_idmap = &nop_mnt_idmap;
- ve_mount_nr_inc(mnt);
+ ve_mount_nr_inc(mnt, owner_ve);
}
return mnt;
@@ -1223,7 +1223,7 @@ struct vfsmount *vfs_create_mount(struct fs_context *fc)
if (!fc->root)
return ERR_PTR(-EINVAL);
- mnt = alloc_vfsmnt(fc->source ?: "none");
+ mnt = alloc_vfsmnt(fc->source ?: "none", NULL);
if (!mnt)
return ERR_PTR(-ENOMEM);
@@ -1325,13 +1325,13 @@ vfs_submount(const struct dentry *mountpoint, struct file_system_type *type,
EXPORT_SYMBOL_GPL(vfs_submount);
static struct mount *clone_mnt(struct mount *old, struct dentry *root,
- int flag)
+ int flag, struct ve_struct *owner_ve)
{
struct super_block *sb = old->mnt.mnt_sb;
struct mount *mnt;
int err;
- mnt = alloc_vfsmnt(old->mnt_devname);
+ mnt = alloc_vfsmnt(old->mnt_devname, owner_ve);
if (!mnt)
return ERR_PTR(-ENOMEM);
@@ -1565,7 +1565,7 @@ EXPORT_SYMBOL(path_is_mountpoint);
struct vfsmount *mnt_clone_internal(const struct path *path)
{
struct mount *p;
- p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE);
+ p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE, NULL);
if (IS_ERR(p))
return ERR_CAST(p);
p->mnt.mnt_flags |= MNT_INTERNAL;
@@ -2153,7 +2153,7 @@ static bool mnt_ns_loop(struct dentry *dentry)
}
struct mount *copy_tree(struct mount *src_root, struct dentry *dentry,
- int flag)
+ int flag, struct ve_struct *owner_ve)
{
struct mount *res, *src_parent, *src_root_child, *src_mnt,
*dst_parent, *dst_mnt;
@@ -2164,7 +2164,7 @@ struct mount *copy_tree(struct mount *src_root, struct dentry *dentry,
if (!(flag & CL_COPY_MNT_NS_FILE) && is_mnt_ns_file(dentry))
return ERR_PTR(-EINVAL);
- res = dst_mnt = clone_mnt(src_root, dentry, flag);
+ res = dst_mnt = clone_mnt(src_root, dentry, flag, owner_ve);
if (IS_ERR(dst_mnt))
return dst_mnt;
@@ -2200,7 +2200,8 @@ struct mount *copy_tree(struct mount *src_root, struct dentry *dentry,
src_parent = src_mnt;
dst_parent = dst_mnt;
- dst_mnt = clone_mnt(src_mnt, src_mnt->mnt.mnt_root, flag);
+ dst_mnt = clone_mnt(src_mnt, src_mnt->mnt.mnt_root, flag,
+ owner_ve);
if (IS_ERR(dst_mnt))
goto out;
lock_mount_hash();
@@ -2230,7 +2231,7 @@ struct vfsmount *collect_mounts(const struct path *path)
tree = ERR_PTR(-EINVAL);
else
tree = copy_tree(real_mount(path->mnt), path->dentry,
- CL_COPY_ALL | CL_PRIVATE);
+ CL_COPY_ALL | CL_PRIVATE, NULL);
namespace_unlock();
if (IS_ERR(tree))
return ERR_CAST(tree);
@@ -2311,7 +2312,7 @@ struct vfsmount *clone_private_mount(const struct path *path)
if (has_locked_children(old_mnt, path->dentry))
goto invalid;
- new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE);
+ new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE, NULL);
up_read(&namespace_sem);
if (IS_ERR(new_mnt))
@@ -2803,9 +2804,10 @@ static struct mount *__do_loopback(struct path *old_path, int recurse)
return mnt;
if (recurse)
- mnt = copy_tree(old, old_path->dentry, CL_COPY_MNT_NS_FILE);
+ mnt = copy_tree(old, old_path->dentry, CL_COPY_MNT_NS_FILE,
+ NULL);
else
- mnt = clone_mnt(old, old_path->dentry, 0);
+ mnt = clone_mnt(old, old_path->dentry, 0, NULL);
if (!IS_ERR(mnt))
mnt->mnt.mnt_flags &= ~MNT_LOCKED;
@@ -3221,9 +3223,10 @@ static inline int ve_mount_allowed(void)
atomic_read(&ve->mnt_nr) < (int)sysctl_ve_mount_nr;
}
-static inline void ve_mount_nr_inc(struct mount *mnt)
+static inline void ve_mount_nr_inc(struct mount *mnt, struct ve_struct *ve)
{
- struct ve_struct *ve = get_exec_env();
+ if (!ve)
+ ve = get_exec_env();
mnt->ve_owner = get_ve(ve);
atomic_inc(&ve->mnt_nr);
@@ -3258,7 +3261,7 @@ bool is_sb_ve_accessible(struct ve_struct *ve, struct super_block *sb)
#else /* CONFIG_VE */
static inline int ve_mount_allowed(void) { return 1; }
-static inline void ve_mount_nr_inc(struct mount *mnt) { }
+static inline void ve_mount_nr_inc(struct mount *mnt, struct ve_struct *ve) { }
static inline void ve_mount_nr_dec(struct mount *mnt) { }
#endif /* CONFIG_VE */
@@ -4235,7 +4238,11 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE;
if (user_ns != ns->user_ns)
copy_flags |= CL_SHARED_TO_SLAVE;
- new = copy_tree(old, old->mnt.mnt_root, copy_flags);
+#ifdef CONFIG_VE
+ new = copy_tree(old, old->mnt.mnt_root, copy_flags, new_ns->ve_owner);
+#else
+ new = copy_tree(old, old->mnt.mnt_root, copy_flags, NULL);
+#endif
if (IS_ERR(new)) {
namespace_unlock();
ns_free_inum(&new_ns->ns);
diff --git a/fs/pnode.c b/fs/pnode.c
index a799e0315cc9..a91e7aac1601 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -257,7 +257,7 @@ static int propagate_one(struct mount *m, struct mountpoint *dest_mp)
type |= CL_MAKE_SHARED;
}
- child = copy_tree(last_source, last_source->mnt.mnt_root, type);
+ child = copy_tree(last_source, last_source->mnt.mnt_root, type, NULL);
if (IS_ERR(child))
return PTR_ERR(child);
read_seqlock_excl(&mount_lock);
diff --git a/fs/pnode.h b/fs/pnode.h
index 0b02a6393891..c865dd91f0a3 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -10,6 +10,8 @@
#include <linux/list.h>
#include "mount.h"
+struct ve_struct;
+
#define IS_MNT_SHARED(m) ((m)->mnt.mnt_flags & MNT_SHARED)
#define IS_MNT_SLAVE(m) ((m)->mnt_master)
#define IS_MNT_NEW(m) (!(m)->mnt_ns || is_anon_ns((m)->mnt_ns))
@@ -49,7 +51,8 @@ void mnt_set_mountpoint(struct mount *, struct mountpoint *,
struct mount *);
void mnt_change_mountpoint(struct mount *parent, struct mountpoint *mp,
struct mount *mnt);
-struct mount *copy_tree(struct mount *, struct dentry *, int);
+struct mount *copy_tree(struct mount *, struct dentry *, int,
+ struct ve_struct *);
bool is_path_reachable(struct mount *, struct dentry *,
const struct path *root);
int count_mounts(struct mnt_namespace *ns, struct mount *mnt);
--
2.53.0
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