Commit cbae4d12 authored by Al Viro's avatar Al Viro
Browse files

fold handle_mounts() into step_into() 



The following is true:
	* calls of handle_mounts() and step_into() are always
paired in sequences like
	err = handle_mounts(nd, dentry, &path, &inode, &seq);
	if (unlikely(err < 0))
		return err;
	err = step_into(nd, &path, flags, inode, seq);
	* in all such sequences path is uninitialized before and
unused after this pair of calls
	* in all such sequences inode and seq are unused afterwards.

So the call of handle_mounts() can be shifted inside step_into(),
turning 'path' into a local variable in the combined function.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent aca2903e

fs/namei.c

+15 −26
Original line number Diff line number Diff line
@@ -1835,29 +1835,33 @@ enum {WALK_FOLLOW = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4}; 
 * so we keep a cache of "no, this doesn't need follow_link"

 * for the common case.

 */

static inline int step_into(struct nameidata *nd, struct path *path,

			    int flags, struct inode *inode, unsigned seq)

static int step_into(struct nameidata *nd, int flags,

		     struct dentry *dentry, struct inode *inode, unsigned seq)

{

	if (likely(!d_is_symlink(path->dentry)) ||

	struct path path;

	int err = handle_mounts(nd, dentry, &path, &inode, &seq);



	if (err < 0)

		return err;

	if (likely(!d_is_symlink(path.dentry)) ||

	   !((flags & WALK_FOLLOW) || (nd->flags & LOOKUP_FOLLOW)) ||

	   (flags & WALK_NOFOLLOW)) {

		/* not a symlink or should not follow */

		path_to_nameidata(path, nd);

		path_to_nameidata(&path, nd);

		nd->inode = inode;

		nd->seq = seq;

		return 0;

	}

	/* make sure that d_is_symlink above matches inode */

	if (nd->flags & LOOKUP_RCU) {

		if (read_seqcount_retry(&path->dentry->d_seq, seq))

		if (read_seqcount_retry(&path.dentry->d_seq, seq))

			return -ECHILD;

	}

	return pick_link(nd, path, inode, seq);

	return pick_link(nd, &path, inode, seq);

}



static int walk_component(struct nameidata *nd, int flags)

{

	struct path path;

	struct dentry *dentry;

	struct inode *inode;

	unsigned seq;
@@ -1883,11 +1887,7 @@ static int walk_component(struct nameidata *nd, int flags) 
	}

	if (!(flags & WALK_MORE) && nd->depth)

		put_link(nd);



	err = handle_mounts(nd, dentry, &path, &inode, &seq);

	if (unlikely(err < 0))

			return err;

	return step_into(nd, &path, flags, inode, seq);

	return step_into(nd, flags, dentry, inode, seq);

}



/*
@@ -2354,17 +2354,10 @@ static inline int lookup_last(struct nameidata *nd) 


static int handle_lookup_down(struct nameidata *nd)

{

	struct path path;

	struct inode *inode = nd->inode;

	unsigned seq = nd->seq;

	int err;



	if (!(nd->flags & LOOKUP_RCU))

		dget(nd->path.dentry);

	err = handle_mounts(nd, nd->path.dentry, &path, &inode, &seq);

	if (unlikely(err < 0))

		return err;

	return step_into(nd, &path, WALK_NOFOLLOW, inode, seq);

	return step_into(nd, WALK_NOFOLLOW,

			nd->path.dentry, nd->inode, nd->seq);

}



/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
@@ -3281,7 +3274,6 @@ static int do_last(struct nameidata *nd, 
	int acc_mode = op->acc_mode;

	unsigned seq;

	struct inode *inode;

	struct path path;

	struct dentry *dentry;

	int error;
@@ -3384,10 +3376,7 @@ static int do_last(struct nameidata *nd, 
finish_lookup:

	if (nd->depth)

		put_link(nd);

	error = handle_mounts(nd, dentry, &path, &inode, &seq);

	if (unlikely(error < 0))

		return error;

	error = step_into(nd, &path, 0, inode, seq);

	error = step_into(nd, 0, dentry, inode, seq);

	if (unlikely(error))

		return error;

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