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: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index 5d31f0b..092ac56 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -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)))
+ 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;
- if (!(flags & WALK_GET) && !(nd->flags & LOOKUP_FOLLOW))
- 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;
