[PATCH] new (local) helper: user_path_parent()
Preparation to untangling intents mess: reduce the number of do_path_lookup() callers. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
2d8f30380a
commit
2ad94ae654
1 changed files with 57 additions and 80 deletions
137
fs/namei.c
137
fs/namei.c
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@ -1352,6 +1352,24 @@ int user_path_at(int dfd, const char __user *name, unsigned flags,
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return err;
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}
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static int user_path_parent(int dfd, const char __user *path,
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struct nameidata *nd, char **name)
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{
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char *s = getname(path);
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int error;
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if (IS_ERR(s))
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return PTR_ERR(s);
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error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd);
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if (error)
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putname(s);
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else
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*name = s;
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return error;
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}
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/*
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* It's inline, so penalty for filesystems that don't use sticky bit is
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* minimal.
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@ -1989,20 +2007,18 @@ static int may_mknod(mode_t mode)
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asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
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unsigned dev)
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{
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int error = 0;
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char * tmp;
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struct dentry * dentry;
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int error;
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char *tmp;
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struct dentry *dentry;
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struct nameidata nd;
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if (S_ISDIR(mode))
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return -EPERM;
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tmp = getname(filename);
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if (IS_ERR(tmp))
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return PTR_ERR(tmp);
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error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
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error = user_path_parent(dfd, filename, &nd, &tmp);
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if (error)
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goto out;
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return error;
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dentry = lookup_create(&nd, 0);
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if (IS_ERR(dentry)) {
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error = PTR_ERR(dentry);
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@ -2034,7 +2050,6 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode,
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out_unlock:
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mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
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path_put(&nd.path);
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out:
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putname(tmp);
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return error;
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@ -2074,14 +2089,10 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
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struct dentry *dentry;
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struct nameidata nd;
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tmp = getname(pathname);
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error = PTR_ERR(tmp);
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if (IS_ERR(tmp))
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error = user_path_parent(dfd, pathname, &nd, &tmp);
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if (error)
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goto out_err;
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error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 1);
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error = PTR_ERR(dentry);
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if (IS_ERR(dentry))
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@ -2099,7 +2110,6 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode)
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out_unlock:
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mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
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path_put(&nd.path);
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out:
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putname(tmp);
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out_err:
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return error;
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@ -2177,13 +2187,9 @@ static long do_rmdir(int dfd, const char __user *pathname)
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struct dentry *dentry;
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struct nameidata nd;
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name = getname(pathname);
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if(IS_ERR(name))
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return PTR_ERR(name);
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error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
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error = user_path_parent(dfd, pathname, &nd, &name);
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if (error)
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goto exit;
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return error;
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switch(nd.last_type) {
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case LAST_DOTDOT:
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@ -2212,7 +2218,6 @@ static long do_rmdir(int dfd, const char __user *pathname)
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mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
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exit1:
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path_put(&nd.path);
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exit:
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putname(name);
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return error;
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}
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@ -2261,19 +2266,16 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
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*/
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static long do_unlinkat(int dfd, const char __user *pathname)
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{
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int error = 0;
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char * name;
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int error;
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char *name;
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struct dentry *dentry;
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struct nameidata nd;
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struct inode *inode = NULL;
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name = getname(pathname);
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if(IS_ERR(name))
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return PTR_ERR(name);
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error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd);
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error = user_path_parent(dfd, pathname, &nd, &name);
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if (error)
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goto exit;
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return error;
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error = -EISDIR;
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if (nd.last_type != LAST_NORM)
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goto exit1;
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@ -2300,7 +2302,6 @@ static long do_unlinkat(int dfd, const char __user *pathname)
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iput(inode); /* truncate the inode here */
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exit1:
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path_put(&nd.path);
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exit:
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putname(name);
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return error;
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@ -2350,23 +2351,20 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname)
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asmlinkage long sys_symlinkat(const char __user *oldname,
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int newdfd, const char __user *newname)
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{
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int error = 0;
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char * from;
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char * to;
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int error;
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char *from;
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char *to;
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struct dentry *dentry;
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struct nameidata nd;
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from = getname(oldname);
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if(IS_ERR(from))
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if (IS_ERR(from))
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return PTR_ERR(from);
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to = getname(newname);
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error = PTR_ERR(to);
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if (IS_ERR(to))
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error = user_path_parent(newdfd, newname, &nd, &to);
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if (error)
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goto out_putname;
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error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
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if (error)
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goto out;
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dentry = lookup_create(&nd, 0);
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error = PTR_ERR(dentry);
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if (IS_ERR(dentry))
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@ -2382,7 +2380,6 @@ asmlinkage long sys_symlinkat(const char __user *oldname,
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out_unlock:
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mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
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path_put(&nd.path);
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out:
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putname(to);
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out_putname:
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putname(from);
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@ -2449,21 +2446,18 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
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struct nameidata nd;
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struct path old_path;
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int error;
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char * to;
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char *to;
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if ((flags & ~AT_SYMLINK_FOLLOW) != 0)
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return -EINVAL;
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to = getname(newname);
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if (IS_ERR(to))
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return PTR_ERR(to);
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error = user_path_at(olddfd, oldname,
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flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0,
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&old_path);
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if (error)
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goto exit;
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error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd);
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return error;
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error = user_path_parent(newdfd, newname, &nd, &to);
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if (error)
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goto out;
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error = -EXDEV;
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@ -2484,10 +2478,9 @@ asmlinkage long sys_linkat(int olddfd, const char __user *oldname,
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mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
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out_release:
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path_put(&nd.path);
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putname(to);
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out:
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path_put(&old_path);
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exit:
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putname(to);
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return error;
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}
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@ -2643,20 +2636,22 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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return error;
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}
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static int do_rename(int olddfd, const char *oldname,
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int newdfd, const char *newname)
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asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
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int newdfd, const char __user *newname)
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{
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int error = 0;
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struct dentry * old_dir, * new_dir;
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struct dentry * old_dentry, *new_dentry;
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struct dentry * trap;
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struct dentry *old_dir, *new_dir;
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struct dentry *old_dentry, *new_dentry;
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struct dentry *trap;
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struct nameidata oldnd, newnd;
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char *from;
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char *to;
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int error;
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error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd);
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error = user_path_parent(olddfd, oldname, &oldnd, &from);
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if (error)
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goto exit;
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error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd);
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error = user_path_parent(newdfd, newname, &newnd, &to);
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if (error)
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goto exit1;
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@ -2718,29 +2713,11 @@ static int do_rename(int olddfd, const char *oldname,
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unlock_rename(new_dir, old_dir);
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exit2:
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path_put(&newnd.path);
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putname(to);
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exit1:
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path_put(&oldnd.path);
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exit:
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return error;
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}
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asmlinkage long sys_renameat(int olddfd, const char __user *oldname,
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int newdfd, const char __user *newname)
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{
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int error;
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char * from;
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char * to;
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from = getname(oldname);
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if(IS_ERR(from))
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return PTR_ERR(from);
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to = getname(newname);
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error = PTR_ERR(to);
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if (!IS_ERR(to)) {
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error = do_rename(olddfd, from, newdfd, to);
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putname(to);
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}
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putname(from);
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exit:
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return error;
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}
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