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Commit baa03890 authored by Nick Piggin's avatar Nick Piggin Committed by Al Viro
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fs: dentry allocation consolidation 



fs: dentry allocation consolidation

There are 2 duplicate copies of code in dentry allocation in path lookup.
Consolidate them into a single function.

Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 2e2e88ea

fs/namei.c

+33 −37
Original line number Diff line number Diff line
@@ -685,6 +685,35 @@ static __always_inline void follow_dotdot(struct nameidata *nd) 
	follow_mount(&nd->path);

}



/*

 * Allocate a dentry with name and parent, and perform a parent

 * directory ->lookup on it. Returns the new dentry, or ERR_PTR

 * on error. parent->d_inode->i_mutex must be held. d_lookup must

 * have verified that no child exists while under i_mutex.

 */

static struct dentry *d_alloc_and_lookup(struct dentry *parent,

				struct qstr *name, struct nameidata *nd)

{

	struct inode *inode = parent->d_inode;

	struct dentry *dentry;

	struct dentry *old;



	/* Don't create child dentry for a dead directory. */

	if (unlikely(IS_DEADDIR(inode)))

		return ERR_PTR(-ENOENT);



	dentry = d_alloc(parent, name);

	if (unlikely(!dentry))

		return ERR_PTR(-ENOMEM);



	old = inode->i_op->lookup(inode, dentry, nd);

	if (unlikely(old)) {

		dput(dentry);

		dentry = old;

	}

	return dentry;

}



/*

 *  It's more convoluted than I'd like it to be, but... it's still fairly

 *  small and for now I'd prefer to have fast path as straight as possible.
@@ -738,30 +767,13 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, 
	 * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup

	 */

	dentry = d_lookup(parent, name);

	if (!dentry) {

		struct dentry *new;



		/* Don't create child dentry for a dead directory. */

		dentry = ERR_PTR(-ENOENT);

		if (IS_DEADDIR(dir))

			goto out_unlock;



		new = d_alloc(parent, name);

		dentry = ERR_PTR(-ENOMEM);

		if (new) {

			dentry = dir->i_op->lookup(dir, new, nd);

			if (dentry)

				dput(new);

			else

				dentry = new;

		}

out_unlock:

	if (likely(!dentry)) {

		dentry = d_alloc_and_lookup(parent, name, nd);

		mutex_unlock(&dir->i_mutex);

		if (IS_ERR(dentry))

			goto fail;

		goto done;

	}



	/*

	 * Uhhuh! Nasty case: the cache was re-populated while

	 * we waited on the semaphore. Need to revalidate.
@@ -1135,24 +1147,8 @@ static struct dentry *__lookup_hash(struct qstr *name, 
	if (dentry && dentry->d_op && dentry->d_op->d_revalidate)

		dentry = do_revalidate(dentry, nd);



	if (!dentry) {

		struct dentry *new;



		/* Don't create child dentry for a dead directory. */

		dentry = ERR_PTR(-ENOENT);

		if (IS_DEADDIR(inode))

			goto out;



		new = d_alloc(base, name);

		dentry = ERR_PTR(-ENOMEM);

		if (!new)

			goto out;

		dentry = inode->i_op->lookup(inode, new, nd);

	if (!dentry)

			dentry = new;

		else

			dput(new);

	}

		dentry = d_alloc_and_lookup(base, name, nd);

out:

	return dentry;

}