diff options
| -rw-r--r-- | fs/namei.c | 46 |
1 files changed, 25 insertions, 21 deletions
diff --git a/fs/namei.c b/fs/namei.c index 1f3d3981fe02..6025406e01e5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1580,6 +1580,28 @@ static inline int may_lookup(struct nameidata *nd) return inode_permission(nd->inode, MAY_EXEC); } +static int reserve_stack(struct nameidata *nd, struct path *link, unsigned seq) +{ + int error; + + if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) + return -ELOOP; + error = nd_alloc_stack(nd); + if (likely(!error)) + return 0; + if (error == -ECHILD) { + // we must grab link first + bool grabbed_link = legitimize_path(nd, link, seq); + // ... and we must unlazy to be able to clean up + error = unlazy_walk(nd); + if (unlikely(!grabbed_link)) + error = -ECHILD; + if (!error) + error = nd_alloc_stack(nd); + } + return error; +} + enum {WALK_TRAILING = 1, WALK_MORE = 2, WALK_NOFOLLOW = 4}; static const char *pick_link(struct nameidata *nd, struct path *link, @@ -1587,31 +1609,13 @@ static const char *pick_link(struct nameidata *nd, struct path *link, { struct saved *last; const char *res; - int error; + int error = reserve_stack(nd, link, seq); - if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) { - if (!(nd->flags & LOOKUP_RCU)) - path_put(link); - return ERR_PTR(-ELOOP); - } - error = nd_alloc_stack(nd); if (unlikely(error)) { - if (error == -ECHILD) { - // we must grab link first - bool grabbed_link = legitimize_path(nd, link, seq); - // ... and we must unlazy to be able to clean up - error = unlazy_walk(nd); - if (unlikely(!grabbed_link)) - error = -ECHILD; - if (!error) - error = nd_alloc_stack(nd); - } - if (error) { + if (!(nd->flags & LOOKUP_RCU)) path_put(link); - return ERR_PTR(error); - } + return ERR_PTR(error); } - last = nd->stack + nd->depth++; last->link = *link; clear_delayed_call(&last->done); |