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Commit 8f64fb1c authored by Al Viro's avatar Al Viro
Browse files

namei: fold should_follow_link() with the step into not-followed link 



All callers are followed by the same boilerplate - "if it has returned
0, update nd->path/inode/seq - we are not following a symlink here".
Pull it into the function itself, renaming it into step_into().
Rename WALK_GET to WALK_FOLLOW, while we are at it - more descriptive
name.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 31d66bcd

fs/namei.c

+18 −30
Original line number Diff line number Diff line
@@ -1725,7 +1725,7 @@ static int pick_link(struct nameidata *nd, struct path *link, 
	return 1;

}



enum {WALK_GET = 1, WALK_MORE = 2};

enum {WALK_FOLLOW = 1, WALK_MORE = 2};



/*

 * Do we need to follow links? We _really_ want to be able
@@ -1733,22 +1733,25 @@ enum {WALK_GET = 1, WALK_MORE = 2}; 
 * so we keep a cache of "no, this doesn't need follow_link"

 * for the common case.

 */

static inline int should_follow_link(struct nameidata *nd, struct path *link,

				     int flags,

				     struct inode *inode, unsigned seq)

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

			    int flags, struct inode *inode, unsigned seq)

{

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

		put_link(nd);

	if (likely(!d_is_symlink(link->dentry)))

		return 0;

	if (!(flags & WALK_GET) && !(nd->flags & LOOKUP_FOLLOW))

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

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

		/* not a symlink or should not follow */

		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(&link->dentry->d_seq, seq))

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

			return -ECHILD;

	}

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

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

}



static int walk_component(struct nameidata *nd, int flags)
@@ -1791,13 +1794,7 @@ static int walk_component(struct nameidata *nd, int flags) 
		inode = d_backing_inode(path.dentry);

	}



	err = should_follow_link(nd, &path, flags, inode, seq);

	if (unlikely(err))

		return err;

	path_to_nameidata(&path, nd);

	nd->inode = inode;

	nd->seq = seq;

	return 0;

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

}



/*
@@ -2104,10 +2101,10 @@ static int link_path_walk(const char *name, struct nameidata *nd) 
			if (!name)

				return 0;

			/* last component of nested symlink */

			err = walk_component(nd, WALK_GET);

			err = walk_component(nd, WALK_FOLLOW);

		} else {

			/* not the last component */

			err = walk_component(nd, WALK_GET | WALK_MORE);

			err = walk_component(nd, WALK_FOLLOW | WALK_MORE);

		}

		if (err < 0)

			return err;
@@ -2617,12 +2614,7 @@ mountpoint_last(struct nameidata *nd) 
		return -ENOENT;

	}

	path.mnt = nd->path.mnt;

	error = should_follow_link(nd, &path, 0,

				   d_backing_inode(path.dentry), 0);

	if (unlikely(error))

		return error;

	path_to_nameidata(&path, nd);

	return 0;

	return step_into(nd, &path, 0, d_backing_inode(path.dentry), 0);

}



/**
@@ -3311,15 +3303,11 @@ static int do_last(struct nameidata *nd, 
	seq = 0;	/* out of RCU mode, so the value doesn't matter */

	inode = d_backing_inode(path.dentry);

finish_lookup:

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

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

	if (unlikely(error))

		return error;



	path_to_nameidata(&path, nd);

	nd->inode = inode;

	nd->seq = seq;

	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */

finish_open:

	/* Why this, you ask?  _Now_ we might have grown LOOKUP_JUMPED... */

	error = complete_walk(nd);

	if (error)

		return error;