pick_link(): take reserving space on stack into a new helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-03-03 11:22:34 -05:00
parent aef9404d8c
commit 49055906af

View file

@ -1580,22 +1580,15 @@ static inline int may_lookup(struct nameidata *nd)
return inode_permission(nd->inode, MAY_EXEC);
}
enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4};
static const char *pick_link(struct nameidata *nd, struct path *link,
struct inode *inode, unsigned seq, int flags)
static int reserve_stack(struct nameidata *nd, struct path *link, unsigned seq)
{
struct saved *last;
const char *res;
int error;
if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
if (!(nd->flags & LOOKUP_RCU))
path_put(link);
return ERR_PTR(-ELOOP);
}
if (unlikely(nd->total_link_count++ >= MAXSYMLINKS))
return -ELOOP;
error = nd_alloc_stack(nd);
if (unlikely(error)) {
if (likely(!error))
return 0;
if (error == -ECHILD) {
// we must grab link first
bool grabbed_link = legitimize_path(nd, link, seq);
@ -1606,12 +1599,23 @@ static const char *pick_link(struct nameidata *nd, struct path *link,
if (!error)
error = nd_alloc_stack(nd);
}
if (error) {
return error;
}
enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4};
static const char *pick_link(struct nameidata *nd, struct path *link,
struct inode *inode, unsigned seq, int flags)
{
struct saved *last;
const char *res;
int error = reserve_stack(nd, link, seq);
if (unlikely(error)) {
if (!(nd->flags & LOOKUP_RCU))
path_put(link);
return ERR_PTR(error);
}
}
last = nd->stack + nd->depth++;
last->link = *link;
clear_delayed_call(&last->done);