vfs: spread struct mount - do_umount/propagate_mount_busy (1ab59738) · Commits · 戴 / test

fs/namespace.c

+14 −14

Original line number	Diff line number	Diff line
		@@ -1180,7 +1180,7 @@ int may_umount(struct vfsmount *mnt)
		int ret = 1;
		down_read(&namespace_sem);
		br_write_lock(vfsmount_lock);
		if (propagate_mount_busy(mnt, 2))
		if (propagate_mount_busy(real_mount(mnt), 2))
		ret = 0;
		br_write_unlock(vfsmount_lock);
		up_read(&namespace_sem);
		@@ -1246,13 +1246,13 @@ void umount_tree(struct mount mnt, int propagate, struct list_head kill)

		static void shrink_submounts(struct mount mnt, struct list_head umounts);

		static int do_umount(struct vfsmount *mnt, int flags)
		static int do_umount(struct mount *mnt, int flags)
		{
		struct super_block *sb = mnt->mnt_sb;
		struct super_block *sb = mnt->mnt.mnt_sb;
		int retval;
		LIST_HEAD(umount_list);

		retval = security_sb_umount(mnt, flags);
		retval = security_sb_umount(&mnt->mnt, flags);
		if (retval)
		return retval;

		@@ -1263,7 +1263,7 @@ static int do_umount(struct vfsmount *mnt, int flags)
		* (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
		*/
		if (flags & MNT_EXPIRE) {
		if (mnt == current->fs->root.mnt \|\|
		if (&mnt->mnt == current->fs->root.mnt \|\|
		flags & (MNT_FORCE \| MNT_DETACH))
		return -EINVAL;

		@@ -1272,13 +1272,13 @@ static int do_umount(struct vfsmount *mnt, int flags)
		* all race cases, but it's a slowpath.
		*/
		br_write_lock(vfsmount_lock);
		if (mnt_get_count(mnt) != 2) {
		if (mnt_get_count(&mnt->mnt) != 2) {
		br_write_unlock(vfsmount_lock);
		return -EBUSY;
		}
		br_write_unlock(vfsmount_lock);

		if (!xchg(&mnt->mnt_expiry_mark, 1))
		if (!xchg(&mnt->mnt.mnt_expiry_mark, 1))
		return -EAGAIN;
		}

		@@ -1305,7 +1305,7 @@ static int do_umount(struct vfsmount *mnt, int flags)
		* /reboot - static binary that would close all descriptors and
		* call reboot(9). Then init(8) could umount root and exec /reboot.
		*/
		if (mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
		if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
		/*
		* Special case for "unmounting" root ...
		* we just try to remount it readonly.
		@@ -1322,12 +1322,12 @@ static int do_umount(struct vfsmount *mnt, int flags)
		event++;

		if (!(flags & MNT_DETACH))
		shrink_submounts(real_mount(mnt), &umount_list);
		shrink_submounts(mnt, &umount_list);

		retval = -EBUSY;
		if (flags & MNT_DETACH \|\| !propagate_mount_busy(mnt, 2)) {
		if (!list_empty(&mnt->mnt_list))
		umount_tree(real_mount(mnt), 1, &umount_list);
		if (!list_empty(&mnt->mnt.mnt_list))
		umount_tree(mnt, 1, &umount_list);
		retval = 0;
		}
		br_write_unlock(vfsmount_lock);
		@@ -1369,7 +1369,7 @@ SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
		if (!capable(CAP_SYS_ADMIN))
		goto dput_and_out;

		retval = do_umount(path.mnt, flags);
		retval = do_umount(real_mount(path.mnt), flags);
		dput_and_out:
		/* we mustn't call path_put() as that would clear mnt_expiry_mark */
		dput(path.dentry);
		@@ -2101,7 +2101,7 @@ void mark_mounts_for_expiry(struct list_head *mounts)
		*/
		list_for_each_entry_safe(mnt, next, mounts, mnt.mnt_expire) {
		if (!xchg(&mnt->mnt.mnt_expiry_mark, 1) \|\|
		propagate_mount_busy(&mnt->mnt, 1))
		propagate_mount_busy(mnt, 1))
		continue;
		list_move(&mnt->mnt.mnt_expire, &graveyard);
		}
		@@ -2148,7 +2148,7 @@ resume:
		goto repeat;
		}

		if (!propagate_mount_busy(&mnt->mnt, 1)) {
		if (!propagate_mount_busy(mnt, 1)) {
		list_move_tail(&mnt->mnt.mnt_expire, graveyard);
		found++;
		}

fs/pnode.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -272,9 +272,9 @@ out:
		/*
		* return true if the refcount is greater than count
		*/
		static inline int do_refcount_check(struct vfsmount *mnt, int count)
		static inline int do_refcount_check(struct mount *mnt, int count)
		{
		int mycount = mnt_get_count(mnt) - mnt->mnt_ghosts;
		int mycount = mnt_get_count(&mnt->mnt) - mnt->mnt.mnt_ghosts;
		return (mycount > count);
		}

		@@ -288,14 +288,14 @@ static inline int do_refcount_check(struct vfsmount *mnt, int count)
		*
		* vfsmount lock must be held for write
		*/
		int propagate_mount_busy(struct vfsmount *mnt, int refcnt)
		int propagate_mount_busy(struct mount *mnt, int refcnt)
		{
		struct vfsmount *m;
		struct mount *child;
		struct vfsmount *parent = mnt->mnt_parent;
		struct vfsmount *parent = mnt->mnt.mnt_parent;
		int ret = 0;

		if (mnt == parent)
		if (&mnt->mnt == parent)
		return do_refcount_check(mnt, refcnt);

		/*
		@@ -303,14 +303,14 @@ int propagate_mount_busy(struct vfsmount *mnt, int refcnt)
		* If not, we don't have to go checking for all other
		* mounts
		*/
		if (!list_empty(&mnt->mnt_mounts) \|\| do_refcount_check(mnt, refcnt))
		if (!list_empty(&mnt->mnt.mnt_mounts) \|\| do_refcount_check(mnt, refcnt))
		return 1;

		for (m = propagation_next(parent, parent); m;
		m = propagation_next(m, parent)) {
		child = __lookup_mnt(m, mnt->mnt_mountpoint, 0);
		child = __lookup_mnt(m, mnt->mnt.mnt_mountpoint, 0);
		if (child && list_empty(&child->mnt.mnt_mounts) &&
		(ret = do_refcount_check(&child->mnt, 1)))
		(ret = do_refcount_check(child, 1)))
		break;
		}
		return ret;

fs/pnode.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -33,7 +33,7 @@ void change_mnt_propagation(struct mount *, int);
		int propagate_mnt(struct vfsmount , struct dentry , struct vfsmount *,
		struct list_head *);
		int propagate_umount(struct list_head *);
		int propagate_mount_busy(struct vfsmount *, int);
		int propagate_mount_busy(struct mount *, int);
		void mnt_release_group_id(struct mount *);
		int get_dominating_id(struct vfsmount mnt, const struct path root);
		unsigned int mnt_get_count(struct vfsmount *mnt);

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