namei: pass the struct path to store the result down into path_lookupat()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2015-05-12 16:36:12 -04:00
parent 18d8c86011
commit 625b6d1054

View File

@ -2086,8 +2086,8 @@ static inline int lookup_last(struct nameidata *nd)
}
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
static int path_lookupat(int dfd, const struct filename *name,
unsigned int flags, struct nameidata *nd)
static int path_lookupat(int dfd, const struct filename *name, unsigned flags,
struct nameidata *nd, struct path *path)
{
const char *s = path_init(dfd, name, flags, nd);
int err;
@ -2108,27 +2108,31 @@ static int path_lookupat(int dfd, const struct filename *name,
if (!err && nd->flags & LOOKUP_DIRECTORY)
if (!d_can_lookup(nd->path.dentry))
err = -ENOTDIR;
if (err)
terminate_walk(nd);
if (!err) {
*path = nd->path;
nd->path.mnt = NULL;
nd->path.dentry = NULL;
}
terminate_walk(nd);
path_cleanup(nd);
return err;
}
static int filename_lookup(int dfd, struct filename *name,
unsigned int flags, struct nameidata *nd)
static int filename_lookup(int dfd, struct filename *name, unsigned flags,
struct nameidata *nd, struct path *path)
{
int retval;
struct nameidata *saved_nd = set_nameidata(nd);
retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd, path);
if (unlikely(retval == -ECHILD))
retval = path_lookupat(dfd, name, flags, nd);
retval = path_lookupat(dfd, name, flags, nd, path);
if (unlikely(retval == -ESTALE))
retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL,
nd, path);
if (likely(!retval))
audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
restore_nameidata(saved_nd);
return retval;
}
@ -2209,10 +2213,8 @@ int kern_path(const char *name, unsigned int flags, struct path *path)
int res = PTR_ERR(filename);
if (!IS_ERR(filename)) {
res = filename_lookup(AT_FDCWD, filename, flags, &nd);
res = filename_lookup(AT_FDCWD, filename, flags, &nd, path);
putname(filename);
if (!res)
*path = nd.path;
}
return res;
}
@ -2241,9 +2243,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
nd.root.dentry = dentry;
nd.root.mnt = mnt;
err = filename_lookup(AT_FDCWD, filename,
flags | LOOKUP_ROOT, &nd);
if (!err)
*path = nd.path;
flags | LOOKUP_ROOT, &nd, path);
putname(filename);
}
return err;
@ -2311,10 +2311,8 @@ int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
BUG_ON(flags & LOOKUP_PARENT);
err = filename_lookup(dfd, tmp, flags, &nd);
err = filename_lookup(dfd, tmp, flags, &nd, path);
putname(tmp);
if (!err)
*path = nd.path;
}
return err;
}
@ -3261,44 +3259,42 @@ static int do_tmpfile(int dfd, struct filename *pathname,
struct file *file, int *opened)
{
static const struct qstr name = QSTR_INIT("/", 1);
struct dentry *dentry, *child;
struct dentry *child;
struct inode *dir;
struct path path;
int error = path_lookupat(dfd, pathname,
flags | LOOKUP_DIRECTORY, nd);
flags | LOOKUP_DIRECTORY, nd, &path);
if (unlikely(error))
return error;
error = mnt_want_write(nd->path.mnt);
error = mnt_want_write(path.mnt);
if (unlikely(error))
goto out;
dir = path.dentry->d_inode;
/* we want directory to be writable */
error = inode_permission(nd->inode, MAY_WRITE | MAY_EXEC);
error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)
goto out2;
dentry = nd->path.dentry;
dir = dentry->d_inode;
if (!dir->i_op->tmpfile) {
error = -EOPNOTSUPP;
goto out2;
}
child = d_alloc(dentry, &name);
child = d_alloc(path.dentry, &name);
if (unlikely(!child)) {
error = -ENOMEM;
goto out2;
}
nd->flags &= ~LOOKUP_DIRECTORY;
nd->flags |= op->intent;
dput(nd->path.dentry);
nd->path.dentry = child;
error = dir->i_op->tmpfile(dir, nd->path.dentry, op->mode);
dput(path.dentry);
path.dentry = child;
error = dir->i_op->tmpfile(dir, child, op->mode);
if (error)
goto out2;
audit_inode(pathname, nd->path.dentry, 0);
audit_inode(pathname, child, 0);
/* Don't check for other permissions, the inode was just created */
error = may_open(&nd->path, MAY_OPEN, op->open_flag);
error = may_open(&path, MAY_OPEN, op->open_flag);
if (error)
goto out2;
file->f_path.mnt = nd->path.mnt;
error = finish_open(file, nd->path.dentry, NULL, opened);
file->f_path.mnt = path.mnt;
error = finish_open(file, child, NULL, opened);
if (error)
goto out2;
error = open_check_o_direct(file);
@ -3311,9 +3307,9 @@ static int do_tmpfile(int dfd, struct filename *pathname,
spin_unlock(&inode->i_lock);
}
out2:
mnt_drop_write(nd->path.mnt);
mnt_drop_write(path.mnt);
out:
path_put(&nd->path);
path_put(&path);
return error;
}