Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs (fedc1ed0) · Commits · 戴 / test

fs/mount.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -19,13 +19,13 @@ struct mnt_pcp {
		};

		struct mountpoint {
		struct list_head m_hash;
		struct hlist_node m_hash;
		struct dentry *m_dentry;
		int m_count;
		};

		struct mount {
		struct list_head mnt_hash;
		struct hlist_node mnt_hash;
		struct mount *mnt_parent;
		struct dentry *mnt_mountpoint;
		struct vfsmount mnt;

fs/namespace.c

+115 −62

Original line number	Diff line number	Diff line
		@@ -23,11 +23,34 @@
		#include <linux/uaccess.h>
		#include <linux/proc_ns.h>
		#include <linux/magic.h>
		#include <linux/bootmem.h>
		#include "pnode.h"
		#include "internal.h"

		#define HASH_SHIFT ilog2(PAGE_SIZE / sizeof(struct list_head))
		#define HASH_SIZE (1UL << HASH_SHIFT)
		static unsigned int m_hash_mask __read_mostly;
		static unsigned int m_hash_shift __read_mostly;
		static unsigned int mp_hash_mask __read_mostly;
		static unsigned int mp_hash_shift __read_mostly;

		static __initdata unsigned long mhash_entries;
		static int __init set_mhash_entries(char *str)
		{
		if (!str)
		return 0;
		mhash_entries = simple_strtoul(str, &str, 0);
		return 1;
		}
		__setup("mhash_entries=", set_mhash_entries);

		static __initdata unsigned long mphash_entries;
		static int __init set_mphash_entries(char *str)
		{
		if (!str)
		return 0;
		mphash_entries = simple_strtoul(str, &str, 0);
		return 1;
		}
		__setup("mphash_entries=", set_mphash_entries);

		static int event;
		static DEFINE_IDA(mnt_id_ida);
		@@ -36,8 +59,8 @@ static DEFINE_SPINLOCK(mnt_id_lock);
		static int mnt_id_start = 0;
		static int mnt_group_start = 1;

		static struct list_head *mount_hashtable __read_mostly;
		static struct list_head *mountpoint_hashtable __read_mostly;
		static struct hlist_head *mount_hashtable __read_mostly;
		static struct hlist_head *mountpoint_hashtable __read_mostly;
		static struct kmem_cache *mnt_cache __read_mostly;
		static DECLARE_RWSEM(namespace_sem);

		@@ -55,12 +78,19 @@ EXPORT_SYMBOL_GPL(fs_kobj);
		*/
		__cacheline_aligned_in_smp DEFINE_SEQLOCK(mount_lock);

		static inline unsigned long hash(struct vfsmount mnt, struct dentry dentry)
		static inline struct hlist_head m_hash(struct vfsmount mnt, struct dentry *dentry)
		{
		unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES);
		tmp += ((unsigned long)dentry / L1_CACHE_BYTES);
		tmp = tmp + (tmp >> HASH_SHIFT);
		return tmp & (HASH_SIZE - 1);
		tmp = tmp + (tmp >> m_hash_shift);
		return &mount_hashtable[tmp & m_hash_mask];
		}

		static inline struct hlist_head mp_hash(struct dentry dentry)
		{
		unsigned long tmp = ((unsigned long)dentry / L1_CACHE_BYTES);
		tmp = tmp + (tmp >> mp_hash_shift);
		return &mountpoint_hashtable[tmp & mp_hash_mask];
		}

		/*
		@@ -187,7 +217,7 @@ static struct mount alloc_vfsmnt(const char name)
		mnt->mnt_writers = 0;
		#endif

		INIT_LIST_HEAD(&mnt->mnt_hash);
		INIT_HLIST_NODE(&mnt->mnt_hash);
		INIT_LIST_HEAD(&mnt->mnt_child);
		INIT_LIST_HEAD(&mnt->mnt_mounts);
		INIT_LIST_HEAD(&mnt->mnt_list);
		@@ -575,10 +605,10 @@ bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
		*/
		struct mount __lookup_mnt(struct vfsmount mnt, struct dentry *dentry)
		{
		struct list_head *head = mount_hashtable + hash(mnt, dentry);
		struct hlist_head *head = m_hash(mnt, dentry);
		struct mount *p;

		list_for_each_entry_rcu(p, head, mnt_hash)
		hlist_for_each_entry_rcu(p, head, mnt_hash)
		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry)
		return p;
		return NULL;
		@@ -590,13 +620,17 @@ struct mount __lookup_mnt(struct vfsmount mnt, struct dentry *dentry)
		*/
		struct mount __lookup_mnt_last(struct vfsmount mnt, struct dentry *dentry)
		{
		struct list_head *head = mount_hashtable + hash(mnt, dentry);
		struct mount *p;

		list_for_each_entry_reverse(p, head, mnt_hash)
		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry)
		return p;
		return NULL;
		struct mount p, res;
		res = p = __lookup_mnt(mnt, dentry);
		if (!p)
		goto out;
		hlist_for_each_entry_continue(p, mnt_hash) {
		if (&p->mnt_parent->mnt != mnt \|\| p->mnt_mountpoint != dentry)
		break;
		res = p;
		}
		out:
		return res;
		}

		/*
		@@ -633,11 +667,11 @@ struct vfsmount lookup_mnt(struct path path)

		static struct mountpoint new_mountpoint(struct dentry dentry)
		{
		struct list_head *chain = mountpoint_hashtable + hash(NULL, dentry);
		struct hlist_head *chain = mp_hash(dentry);
		struct mountpoint *mp;
		int ret;

		list_for_each_entry(mp, chain, m_hash) {
		hlist_for_each_entry(mp, chain, m_hash) {
		if (mp->m_dentry == dentry) {
		/* might be worth a WARN_ON() */
		if (d_unlinked(dentry))
		@@ -659,7 +693,7 @@ static struct mountpoint new_mountpoint(struct dentry dentry)

		mp->m_dentry = dentry;
		mp->m_count = 1;
		list_add(&mp->m_hash, chain);
		hlist_add_head(&mp->m_hash, chain);
		return mp;
		}

		@@ -670,7 +704,7 @@ static void put_mountpoint(struct mountpoint *mp)
		spin_lock(&dentry->d_lock);
		dentry->d_flags &= ~DCACHE_MOUNTED;
		spin_unlock(&dentry->d_lock);
		list_del(&mp->m_hash);
		hlist_del(&mp->m_hash);
		kfree(mp);
		}
		}
		@@ -712,7 +746,7 @@ static void detach_mnt(struct mount mnt, struct path old_path)
		mnt->mnt_parent = mnt;
		mnt->mnt_mountpoint = mnt->mnt.mnt_root;
		list_del_init(&mnt->mnt_child);
		list_del_init(&mnt->mnt_hash);
		hlist_del_init_rcu(&mnt->mnt_hash);
		put_mountpoint(mnt->mnt_mp);
		mnt->mnt_mp = NULL;
		}
		@@ -739,15 +773,14 @@ static void attach_mnt(struct mount *mnt,
		struct mountpoint *mp)
		{
		mnt_set_mountpoint(parent, mp, mnt);
		list_add_tail(&mnt->mnt_hash, mount_hashtable +
		hash(&parent->mnt, mp->m_dentry));
		hlist_add_head_rcu(&mnt->mnt_hash, m_hash(&parent->mnt, mp->m_dentry));
		list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
		}

		/*
		* vfsmount lock must be held for write
		*/
		static void commit_tree(struct mount *mnt)
		static void commit_tree(struct mount mnt, struct mount shadows)
		{
		struct mount *parent = mnt->mnt_parent;
		struct mount *m;
		@@ -762,8 +795,11 @@ 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));
		if (shadows)
		hlist_add_after_rcu(&shadows->mnt_hash, &mnt->mnt_hash);
		else
		hlist_add_head_rcu(&mnt->mnt_hash,
		m_hash(&parent->mnt, mnt->mnt_mountpoint));
		list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
		touch_mnt_namespace(n);
		}
		@@ -1153,26 +1189,28 @@ int may_umount(struct vfsmount *mnt)

		EXPORT_SYMBOL(may_umount);

		static LIST_HEAD(unmounted); /* protected by namespace_sem */
		static HLIST_HEAD(unmounted); /* protected by namespace_sem */

		static void namespace_unlock(void)
		{
		struct mount *mnt;
		LIST_HEAD(head);
		struct hlist_head head = unmounted;

		if (likely(list_empty(&unmounted))) {
		if (likely(hlist_empty(&head))) {
		up_write(&namespace_sem);
		return;
		}

		list_splice_init(&unmounted, &head);
		head.first->pprev = &head.first;
		INIT_HLIST_HEAD(&unmounted);

		up_write(&namespace_sem);

		synchronize_rcu();

		while (!list_empty(&head)) {
		mnt = list_first_entry(&head, struct mount, mnt_hash);
		list_del_init(&mnt->mnt_hash);
		while (!hlist_empty(&head)) {
		mnt = hlist_entry(head.first, struct mount, mnt_hash);
		hlist_del_init(&mnt->mnt_hash);
		if (mnt->mnt_ex_mountpoint.mnt)
		path_put(&mnt->mnt_ex_mountpoint);
		mntput(&mnt->mnt);
		@@ -1193,16 +1231,19 @@ static inline void namespace_lock(void)
		*/
		void umount_tree(struct mount *mnt, int how)
		{
		LIST_HEAD(tmp_list);
		HLIST_HEAD(tmp_list);
		struct mount *p;
		struct mount *last = NULL;

		for (p = mnt; p; p = next_mnt(p, mnt))
		list_move(&p->mnt_hash, &tmp_list);
		for (p = mnt; p; p = next_mnt(p, mnt)) {
		hlist_del_init_rcu(&p->mnt_hash);
		hlist_add_head(&p->mnt_hash, &tmp_list);
		}

		if (how)
		propagate_umount(&tmp_list);

		list_for_each_entry(p, &tmp_list, mnt_hash) {
		hlist_for_each_entry(p, &tmp_list, mnt_hash) {
		list_del_init(&p->mnt_expire);
		list_del_init(&p->mnt_list);
		__touch_mnt_namespace(p->mnt_ns);
		@@ -1220,8 +1261,13 @@ void umount_tree(struct mount *mnt, int how)
		p->mnt_mp = NULL;
		}
		change_mnt_propagation(p, MS_PRIVATE);
		last = p;
		}
		if (last) {
		last->mnt_hash.next = unmounted.first;
		unmounted.first = tmp_list.first;
		unmounted.first->pprev = &unmounted.first;
		}
		list_splice(&tmp_list, &unmounted);
		}

		static void shrink_submounts(struct mount *mnt);
		@@ -1605,24 +1651,23 @@ static int attach_recursive_mnt(struct mount *source_mnt,
		struct mountpoint *dest_mp,
		struct path *parent_path)
		{
		LIST_HEAD(tree_list);
		HLIST_HEAD(tree_list);
		struct mount child, p;
		struct hlist_node *n;
		int err;

		if (IS_MNT_SHARED(dest_mnt)) {
		err = invent_group_ids(source_mnt, true);
		if (err)
		goto out;
		}
		err = propagate_mnt(dest_mnt, dest_mp, source_mnt, &tree_list);
		if (err)
		goto out_cleanup_ids;

		lock_mount_hash();

		if (IS_MNT_SHARED(dest_mnt)) {
		for (p = source_mnt; p; p = next_mnt(p, source_mnt))
		set_mnt_shared(p);
		} else {
		lock_mount_hash();
		}
		if (parent_path) {
		detach_mnt(source_mnt, parent_path);
		@@ -1630,19 +1675,21 @@ static int attach_recursive_mnt(struct mount *source_mnt,
		touch_mnt_namespace(source_mnt->mnt_ns);
		} else {
		mnt_set_mountpoint(dest_mnt, dest_mp, source_mnt);
		commit_tree(source_mnt);
		commit_tree(source_mnt, NULL);
		}

		list_for_each_entry_safe(child, p, &tree_list, mnt_hash) {
		list_del_init(&child->mnt_hash);
		commit_tree(child);
		hlist_for_each_entry_safe(child, n, &tree_list, mnt_hash) {
		struct mount *q;
		hlist_del_init(&child->mnt_hash);
		q = __lookup_mnt_last(&child->mnt_parent->mnt,
		child->mnt_mountpoint);
		commit_tree(child, q);
		}
		unlock_mount_hash();

		return 0;

		out_cleanup_ids:
		if (IS_MNT_SHARED(dest_mnt))
		cleanup_group_ids(source_mnt, NULL);
		out:
		return err;
		@@ -2777,18 +2824,24 @@ void __init mnt_init(void)
		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);
		mountpoint_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC);
		mount_hashtable = alloc_large_system_hash("Mount-cache",
		sizeof(struct hlist_head),
		mhash_entries, 19,
		0,
		&m_hash_shift, &m_hash_mask, 0, 0);
		mountpoint_hashtable = alloc_large_system_hash("Mountpoint-cache",
		sizeof(struct hlist_head),
		mphash_entries, 19,
		0,
		&mp_hash_shift, &mp_hash_mask, 0, 0);

		if (!mount_hashtable \|\| !mountpoint_hashtable)
		panic("Failed to allocate mount hash table\n");

		printk(KERN_INFO "Mount-cache hash table entries: %lu\n", HASH_SIZE);

		for (u = 0; u < HASH_SIZE; u++)
		INIT_LIST_HEAD(&mount_hashtable[u]);
		for (u = 0; u < HASH_SIZE; u++)
		INIT_LIST_HEAD(&mountpoint_hashtable[u]);
		for (u = 0; u <= m_hash_mask; u++)
		INIT_HLIST_HEAD(&mount_hashtable[u]);
		for (u = 0; u <= mp_hash_mask; u++)
		INIT_HLIST_HEAD(&mountpoint_hashtable[u]);

		kernfs_init();

fs/pnode.c

+15 −11

Original line number	Diff line number	Diff line
		@@ -220,14 +220,14 @@ static struct mount get_source(struct mount dest,
		* @tree_list : list of heads of trees to be attached.
		*/
		int propagate_mnt(struct mount dest_mnt, struct mountpoint dest_mp,
		struct mount source_mnt, struct list_head tree_list)
		struct mount source_mnt, struct hlist_head tree_list)
		{
		struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns;
		struct mount m, child;
		int ret = 0;
		struct mount *prev_dest_mnt = dest_mnt;
		struct mount *prev_src_mnt = source_mnt;
		LIST_HEAD(tmp_list);
		HLIST_HEAD(tmp_list);

		for (m = propagation_next(dest_mnt, dest_mnt); m;
		m = propagation_next(m, dest_mnt)) {
		@@ -246,27 +246,29 @@ int propagate_mnt(struct mount dest_mnt, struct mountpoint dest_mp,
		child = copy_tree(source, source->mnt.mnt_root, type);
		if (IS_ERR(child)) {
		ret = PTR_ERR(child);
		list_splice(tree_list, tmp_list.prev);
		tmp_list = *tree_list;
		tmp_list.first->pprev = &tmp_list.first;
		INIT_HLIST_HEAD(tree_list);
		goto out;
		}

		if (is_subdir(dest_mp->m_dentry, m->mnt.mnt_root)) {
		mnt_set_mountpoint(m, dest_mp, child);
		list_add_tail(&child->mnt_hash, tree_list);
		hlist_add_head(&child->mnt_hash, tree_list);
		} else {
		/*
		* This can happen if the parent mount was bind mounted
		* on some subdirectory of a shared/slave mount.
		*/
		list_add_tail(&child->mnt_hash, &tmp_list);
		hlist_add_head(&child->mnt_hash, &tmp_list);
		}
		prev_dest_mnt = m;
		prev_src_mnt = child;
		}
		out:
		lock_mount_hash();
		while (!list_empty(&tmp_list)) {
		child = list_first_entry(&tmp_list, struct mount, mnt_hash);
		while (!hlist_empty(&tmp_list)) {
		child = hlist_entry(tmp_list.first, struct mount, mnt_hash);
		umount_tree(child, 0);
		}
		unlock_mount_hash();
		@@ -338,8 +340,10 @@ static void __propagate_umount(struct mount *mnt)
		* umount the child only if the child has no
		* other children
		*/
		if (child && list_empty(&child->mnt_mounts))
		list_move_tail(&child->mnt_hash, &mnt->mnt_hash);
		if (child && list_empty(&child->mnt_mounts)) {
		hlist_del_init_rcu(&child->mnt_hash);
		hlist_add_before_rcu(&child->mnt_hash, &mnt->mnt_hash);
		}
		}
		}

		@@ -350,11 +354,11 @@ static void __propagate_umount(struct mount *mnt)
		*
		* vfsmount lock must be held for write
		*/
		int propagate_umount(struct list_head *list)
		int propagate_umount(struct hlist_head *list)
		{
		struct mount *mnt;

		list_for_each_entry(mnt, list, mnt_hash)
		hlist_for_each_entry(mnt, list, mnt_hash)
		__propagate_umount(mnt);
		return 0;
		}

fs/pnode.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -36,8 +36,8 @@ static inline void set_mnt_shared(struct mount *mnt)

		void change_mnt_propagation(struct mount *, int);
		int propagate_mnt(struct mount , struct mountpoint , struct mount *,
		struct list_head *);
		int propagate_umount(struct list_head *);
		struct hlist_head *);
		int propagate_umount(struct hlist_head *);
		int propagate_mount_busy(struct mount *, int);
		void mnt_release_group_id(struct mount *);
		int get_dominating_id(struct mount mnt, const struct path root);

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