Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 (055d2194) · Commits · 戴 / test

fs/namei.c

+57 −65

Original line number	Diff line number	Diff line
		@@ -455,14 +455,6 @@ static int nameidata_dentry_drop_rcu(struct nameidata nd, struct dentry dentry
		struct fs_struct *fs = current->fs;
		struct dentry *parent = nd->path.dentry;

		/*
		* It can be possible to revalidate the dentry that we started
		* the path walk with. force_reval_path may also revalidate the
		* dentry already committed to the nameidata.
		*/
		if (unlikely(parent == dentry))
		return nameidata_drop_rcu(nd);

		BUG_ON(!(nd->flags & LOOKUP_RCU));
		if (nd->root.mnt) {
		spin_lock(&fs->lock);
		@@ -571,33 +563,15 @@ void release_open_intent(struct nameidata *nd)
		}
		}

		/*
		* Call d_revalidate and handle filesystems that request rcu-walk
		* to be dropped. This may be called and return in rcu-walk mode,
		* regardless of success or error. If -ECHILD is returned, the caller
		* must return -ECHILD back up the path walk stack so path walk may
		* be restarted in ref-walk mode.
		*/
		static int d_revalidate(struct dentry dentry, struct nameidata nd)
		static inline int d_revalidate(struct dentry dentry, struct nameidata nd)
		{
		int status;

		status = dentry->d_op->d_revalidate(dentry, nd);
		if (status == -ECHILD) {
		if (nameidata_dentry_drop_rcu(nd, dentry))
		return status;
		status = dentry->d_op->d_revalidate(dentry, nd);
		}

		return status;
		return dentry->d_op->d_revalidate(dentry, nd);
		}

		static inline struct dentry *
		static struct dentry *
		do_revalidate(struct dentry dentry, struct nameidata nd)
		{
		int status;

		status = d_revalidate(dentry, nd);
		int status = d_revalidate(dentry, nd);
		if (unlikely(status <= 0)) {
		/*
		* The dentry failed validation.
		@@ -606,21 +580,36 @@ do_revalidate(struct dentry dentry, struct nameidata nd)
		* to return a fail status.
		*/
		if (status < 0) {
		/* If we're in rcu-walk, we don't have a ref */
		if (!(nd->flags & LOOKUP_RCU))
		dput(dentry);
		dentry = ERR_PTR(status);
		} else if (!d_invalidate(dentry)) {
		dput(dentry);
		dentry = NULL;
		}
		}
		return dentry;
		}

		} else {
		static inline struct dentry *
		do_revalidate_rcu(struct dentry dentry, struct nameidata nd)
		{
		int status = d_revalidate(dentry, nd);
		if (likely(status > 0))
		return dentry;
		if (status == -ECHILD) {
		if (nameidata_dentry_drop_rcu(nd, dentry))
		return ERR_PTR(-ECHILD);
		return do_revalidate(dentry, nd);
		}
		if (status < 0)
		return ERR_PTR(status);
		/* Don't d_invalidate in rcu-walk mode */
		if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
		if (nameidata_dentry_drop_rcu(nd, dentry))
		return ERR_PTR(-ECHILD);
		if (!d_invalidate(dentry)) {
		dput(dentry);
		dentry = NULL;
		}
		}
		}
		return dentry;
		}

		@@ -668,9 +657,6 @@ force_reval_path(struct path path, struct nameidata nd)
		return 0;

		if (!status) {
		/* Don't d_invalidate in rcu-walk mode */
		if (nameidata_drop_rcu(nd))
		return -ECHILD;
		d_invalidate(dentry);
		status = -ESTALE;
		}
		@@ -777,6 +763,8 @@ __do_follow_link(const struct path link, struct nameidata nd, void **p)
		int error;
		struct dentry *dentry = link->dentry;

		BUG_ON(nd->flags & LOOKUP_RCU);

		touch_atime(link->mnt, dentry);
		nd_set_link(nd, NULL);

		@@ -811,6 +799,11 @@ static inline int do_follow_link(struct path path, struct nameidata nd)
		{
		void *cookie;
		int err = -ELOOP;

		/* We drop rcu-walk here */
		if (nameidata_dentry_drop_rcu_maybe(nd, path->dentry))
		return -ECHILD;

		if (current->link_count >= MAX_NESTED_LINKS)
		goto loop;
		if (current->total_link_count >= 40)
		@@ -1255,9 +1248,15 @@ static int do_lookup(struct nameidata nd, struct qstr name,
		return -ECHILD;

		nd->seq = seq;
		if (dentry->d_flags & DCACHE_OP_REVALIDATE)
		goto need_revalidate;
		done2:
		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
		dentry = do_revalidate_rcu(dentry, nd);
		if (!dentry)
		goto need_lookup;
		if (IS_ERR(dentry))
		goto fail;
		if (!(nd->flags & LOOKUP_RCU))
		goto done;
		}
		path->mnt = mnt;
		path->dentry = dentry;
		if (likely(__follow_mount_rcu(nd, path, inode, false)))
		@@ -1270,8 +1269,13 @@ done2:
		if (!dentry)
		goto need_lookup;
		found:
		if (dentry->d_flags & DCACHE_OP_REVALIDATE)
		goto need_revalidate;
		if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
		dentry = do_revalidate(dentry, nd);
		if (!dentry)
		goto need_lookup;
		if (IS_ERR(dentry))
		goto fail;
		}
		done:
		path->mnt = mnt;
		path->dentry = dentry;
		@@ -1313,16 +1317,6 @@ need_lookup:
		mutex_unlock(&dir->i_mutex);
		goto found;

		need_revalidate:
		dentry = do_revalidate(dentry, nd);
		if (!dentry)
		goto need_lookup;
		if (IS_ERR(dentry))
		goto fail;
		if (nd->flags & LOOKUP_RCU)
		goto done2;
		goto done;

		fail:
		return PTR_ERR(dentry);
		}
		@@ -1419,9 +1413,6 @@ exec_again:
		goto out_dput;

		if (inode->i_op->follow_link) {
		/* We commonly drop rcu-walk here */
		if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
		return -ECHILD;
		BUG_ON(inode != next.dentry->d_inode);
		err = do_follow_link(&next, nd);
		if (err)
		@@ -1467,8 +1458,6 @@ last_component:
		break;
		if (inode && unlikely(inode->i_op->follow_link) &&
		(lookup_flags & LOOKUP_FOLLOW)) {
		if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
		return -ECHILD;
		BUG_ON(inode != next.dentry->d_inode);
		err = do_follow_link(&next, nd);
		if (err)
		@@ -1504,12 +1493,15 @@ return_reval:
		* We may need to check the cached dentry for staleness.
		*/
		if (need_reval_dot(nd->path.dentry)) {
		if (nameidata_drop_rcu_last_maybe(nd))
		return -ECHILD;
		/* Note: we do not d_invalidate() */
		err = d_revalidate(nd->path.dentry, nd);
		if (!err)
		err = -ESTALE;
		if (err < 0)
		break;
		return 0;
		}
		return_base:
		if (nameidata_drop_rcu_last_maybe(nd))

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