do_last: move path there from caller's stack frame

We used to need it to feed to follow_link().  No more...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/namei.c b/fs/namei.c
index 06c3e4a..8582907 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2911,7 +2911,7 @@ out_dput:
 /*
  * Handle the last step of open()
  */
-static int do_last(struct nameidata *nd, struct path *path,
+static int do_last(struct nameidata *nd,
                   struct file *file, const struct open_flags *op,
                   int *opened, struct filename *name)
 {
@@ -2922,6 +2922,7 @@ static int do_last(struct nameidata *nd, struct path *path,
        int acc_mode = op->acc_mode;
        struct inode *inode;
        struct path save_parent = { .dentry = NULL, .mnt = NULL };
+       struct path path;
        bool retried = false;
        int error;
 
@@ -2939,7 +2940,7 @@ static int do_last(struct nameidata *nd, struct path *path,
                if (nd->last.name[nd->last.len])
                        nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
                /* we _can_ be in RCU mode here */
-               error = lookup_fast(nd, path, &inode);
+               error = lookup_fast(nd, &path, &inode);
                if (likely(!error))
                        goto finish_lookup;
 
@@ -2977,7 +2978,7 @@ retry_lookup:
                 */
        }
        mutex_lock(&dir->d_inode->i_mutex);
-       error = lookup_open(nd, path, file, op, got_write, opened);
+       error = lookup_open(nd, &path, file, op, got_write, opened);
        mutex_unlock(&dir->d_inode->i_mutex);
 
        if (error <= 0) {
@@ -2997,15 +2998,15 @@ retry_lookup:
                open_flag &= ~O_TRUNC;
                will_truncate = false;
                acc_mode = MAY_OPEN;
-               path_to_nameidata(path, nd);
+               path_to_nameidata(&path, nd);
                goto finish_open_created;
        }
 
        /*
         * create/update audit record if it already exists.
         */
-       if (d_is_positive(path->dentry))
-               audit_inode(name, path->dentry, 0);
+       if (d_is_positive(path.dentry))
+               audit_inode(name, path.dentry, 0);
 
        /*
         * If atomic_open() acquired write access it is dropped now due to
@@ -3021,7 +3022,7 @@ retry_lookup:
        if ((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))
                goto exit_dput;
 
-       error = follow_managed(path, nd->flags);
+       error = follow_managed(&path, nd->flags);
        if (error < 0)
                goto exit_dput;
 
@@ -3029,38 +3030,38 @@ retry_lookup:
                nd->flags |= LOOKUP_JUMPED;
 
        BUG_ON(nd->flags & LOOKUP_RCU);
-       inode = path->dentry->d_inode;
+       inode = path.dentry->d_inode;
        error = -ENOENT;
-       if (d_is_negative(path->dentry)) {
-               path_to_nameidata(path, nd);
+       if (d_is_negative(path.dentry)) {
+               path_to_nameidata(&path, nd);
                goto out;
        }
 finish_lookup:
-       if (should_follow_link(path->dentry, nd->flags & LOOKUP_FOLLOW)) {
+       if (should_follow_link(path.dentry, nd->flags & LOOKUP_FOLLOW)) {
                if (nd->flags & LOOKUP_RCU) {
-                       if (unlikely(nd->path.mnt != path->mnt ||
-                                    unlazy_walk(nd, path->dentry))) {
+                       if (unlikely(nd->path.mnt != path.mnt ||
+                                    unlazy_walk(nd, path.dentry))) {
                                error = -ECHILD;
                                goto out;
                        }
                }
-               BUG_ON(inode != path->dentry->d_inode);
-               nd->link = *path;
+               BUG_ON(inode != path.dentry->d_inode);
+               nd->link = path;
                return 1;
        }
 
-       if (unlikely(d_is_symlink(path->dentry)) && !(open_flag & O_PATH)) {
-               path_to_nameidata(path, nd);
+       if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
+               path_to_nameidata(&path, nd);
                error = -ELOOP;
                goto out;
        }
 
-       if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) {
-               path_to_nameidata(path, nd);
+       if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
+               path_to_nameidata(&path, nd);
        } else {
                save_parent.dentry = nd->path.dentry;
-               save_parent.mnt = mntget(path->mnt);
-               nd->path.dentry = path->dentry;
+               save_parent.mnt = mntget(path.mnt);
+               nd->path.dentry = path.dentry;
 
        }
        nd->inode = inode;
@@ -3122,7 +3123,7 @@ out:
        return error;
 
 exit_dput:
-       path_put_conditional(path, nd);
+       path_put_conditional(&path, nd);
        goto out;
 exit_fput:
        fput(file);
@@ -3213,7 +3214,6 @@ static struct file *path_openat(int dfd, struct filename *pathname,
                struct nameidata *nd, const struct open_flags *op, int flags)
 {
        struct file *file;
-       struct path path;
        int opened = 0;
        int error;
 
@@ -3232,7 +3232,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
        if (unlikely(error))
                goto out;
 
-       error = do_last(nd, &path, file, op, &opened, pathname);
+       error = do_last(nd, file, op, &opened, pathname);
        while (unlikely(error > 0)) { /* trailing symlink */
                struct path link = nd->link;
                void *cookie;
@@ -3244,7 +3244,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
                error = follow_link(&link, nd, &cookie);
                if (unlikely(error))
                        break;
-               error = do_last(nd, &path, file, op, &opened, pathname);
+               error = do_last(nd, file, op, &opened, pathname);
                put_link(nd, &link, cookie);
        }
 out: