vfs: start hiding vfsmount guts series
Almost all fields of struct vfsmount are used only by core VFS (and
a fairly small part of it, at that). The plan: embed struct vfsmount
into struct mount, making the latter visible only to core parts of VFS.
Then move fields from vfsmount to mount, eventually leaving only
mnt_root/mnt_sb/mnt_flags in struct vfsmount. Filesystem code still
gets pointers to struct vfsmount and remains unchanged; all such
pointers go to struct vfsmount embedded into the instances of struct
mount allocated by fs/namespace.c. When fs/namespace.c et.al. get
a pointer to vfsmount, they turn it into pointer to mount (using
container_of) and work with that.
This is the first part of series; struct mount is introduced,
allocation switched to using it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index 86b4f64..dda47fe 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -173,8 +173,9 @@
static struct vfsmount *alloc_vfsmnt(const char *name)
{
- struct vfsmount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
- if (mnt) {
+ struct mount *p = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
+ if (p) {
+ struct vfsmount *mnt = &p->mnt;
int err;
err = mnt_alloc_id(mnt);
@@ -210,16 +211,16 @@
INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
#endif
}
- return mnt;
+ return &p->mnt;
#ifdef CONFIG_SMP
out_free_devname:
- kfree(mnt->mnt_devname);
+ kfree(p->mnt.mnt_devname);
#endif
out_free_id:
- mnt_free_id(mnt);
+ mnt_free_id(&p->mnt);
out_free_cache:
- kmem_cache_free(mnt_cache, mnt);
+ kmem_cache_free(mnt_cache, p);
return NULL;
}
@@ -449,12 +450,13 @@
static void free_vfsmnt(struct vfsmount *mnt)
{
+ struct mount *p = real_mount(mnt);
kfree(mnt->mnt_devname);
mnt_free_id(mnt);
#ifdef CONFIG_SMP
free_percpu(mnt->mnt_pcp);
#endif
- kmem_cache_free(mnt_cache, mnt);
+ kmem_cache_free(mnt_cache, p);
}
/*
@@ -2698,7 +2700,7 @@
init_rwsem(&namespace_sem);
- mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct vfsmount),
+ mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount),
0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
mount_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC);