switch the IO-triggering parts of umount to fs_pin (87b95ce0) · Commits · e / devices / android_kernel_teracube_2e

fs/fs_pin.c

+0 −1

Original line number	Diff line number	Diff line
		#include <linux/fs.h>
		#include <linux/sched.h>
		#include <linux/slab.h>
		#include <linux/fs_pin.h>
		#include "internal.h"
		#include "mount.h"

fs/mount.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -2,6 +2,7 @@
		#include <linux/seq_file.h>
		#include <linux/poll.h>
		#include <linux/ns_common.h>
		#include <linux/fs_pin.h>

		struct mnt_namespace {
		atomic_t count;
		@@ -62,7 +63,8 @@ struct mount {
		int mnt_group_id; /* peer group identifier */
		int mnt_expiry_mark; /* true if marked for expiry */
		struct hlist_head mnt_pins;
		struct path mnt_ex_mountpoint;
		struct fs_pin mnt_umount;
		struct dentry *mnt_ex_mountpoint;
		};

		#define MNT_NS_INTERNAL ERR_PTR(-EINVAL) /* distinct from any mnt_namespace */

fs/namespace.c

+17 −27

Original line number	Diff line number	Diff line
		@@ -190,6 +190,14 @@ unsigned int mnt_get_count(struct mount *mnt)
		#endif
		}

		static void drop_mountpoint(struct fs_pin *p)
		{
		struct mount *m = container_of(p, struct mount, mnt_umount);
		dput(m->mnt_ex_mountpoint);
		pin_remove(p);
		mntput(&m->mnt);
		}

		static struct mount alloc_vfsmnt(const char name)
		{
		struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
		@@ -229,6 +237,7 @@ static struct mount alloc_vfsmnt(const char name)
		#ifdef CONFIG_FSNOTIFY
		INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
		#endif
		init_fs_pin(&mnt->mnt_umount, drop_mountpoint);
		}
		return mnt;

		@@ -1289,7 +1298,6 @@ static HLIST_HEAD(unmounted); /* protected by namespace_sem */

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

		if (likely(hlist_empty(&head))) {
		@@ -1299,23 +1307,11 @@ static void namespace_unlock(void)

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

		/* undo decrements we'd done in umount_tree() */
		hlist_for_each_entry(mnt, &head, mnt_hash)
		if (mnt->mnt_ex_mountpoint.mnt)
		mntget(mnt->mnt_ex_mountpoint.mnt);

		up_write(&namespace_sem);

		synchronize_rcu();

		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);
		}
		group_pin_kill(&head);
		}

		static inline void namespace_lock(void)
		@@ -1334,7 +1330,6 @@ void umount_tree(struct mount *mnt, int how)
		{
		HLIST_HEAD(tmp_list);
		struct mount *p;
		struct mount *last = NULL;

		for (p = mnt; p; p = next_mnt(p, mnt)) {
		hlist_del_init_rcu(&p->mnt_hash);
		@@ -1347,33 +1342,28 @@ void umount_tree(struct mount *mnt, int how)
		if (how)
		propagate_umount(&tmp_list);

		hlist_for_each_entry(p, &tmp_list, mnt_hash) {
		while (!hlist_empty(&tmp_list)) {
		p = hlist_entry(tmp_list.first, struct mount, mnt_hash);
		hlist_del_init_rcu(&p->mnt_hash);
		list_del_init(&p->mnt_expire);
		list_del_init(&p->mnt_list);
		__touch_mnt_namespace(p->mnt_ns);
		p->mnt_ns = NULL;
		if (how < 2)
		p->mnt.mnt_flags \|= MNT_SYNC_UMOUNT;

		pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, &unmounted);
		if (mnt_has_parent(p)) {
		hlist_del_init(&p->mnt_mp_list);
		put_mountpoint(p->mnt_mp);
		mnt_add_count(p->mnt_parent, -1);
		/* move the reference to mountpoint into ->mnt_ex_mountpoint */
		p->mnt_ex_mountpoint.dentry = p->mnt_mountpoint;
		p->mnt_ex_mountpoint.mnt = &p->mnt_parent->mnt;
		/* old mountpoint will be dropped when we can do that */
		p->mnt_ex_mountpoint = p->mnt_mountpoint;
		p->mnt_mountpoint = p->mnt.mnt_root;
		p->mnt_parent = p;
		p->mnt_mp = NULL;
		}
		change_mnt_propagation(p, MS_PRIVATE);
		last = p;
		}
		if (last) {
		last->mnt_hash.next = unmounted.first;
		if (unmounted.first)
		unmounted.first->pprev = &last->mnt_hash.next;
		unmounted.first = tmp_list.first;
		unmounted.first->pprev = &unmounted.first;
		}
		}