diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namei.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/fs/namei.c b/fs/namei.c index 928cbc856d5b..6dcb1be1aca9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1712,17 +1712,26 @@ static struct dentry *lookup_slow(const struct qstr *name, } static inline int may_lookup(struct mnt_idmap *idmap, - struct nameidata *nd) + struct nameidata *restrict nd) { - if (nd->flags & LOOKUP_RCU) { - int err = inode_permission(idmap, nd->inode, MAY_EXEC|MAY_NOT_BLOCK); - if (!err) // success, keep going - return 0; - if (!try_to_unlazy(nd)) - return -ECHILD; // redo it all non-lazy - if (err != -ECHILD) // hard error - return err; - } + int err, mask; + + mask = nd->flags & LOOKUP_RCU ? MAY_NOT_BLOCK : 0; + err = inode_permission(idmap, nd->inode, mask | MAY_EXEC); + if (likely(!err)) + return 0; + + // If we failed, and we weren't in LOOKUP_RCU, it's final + if (!(nd->flags & LOOKUP_RCU)) + return err; + + // Drop out of RCU mode to make sure it wasn't transient + if (!try_to_unlazy(nd)) + return -ECHILD; // redo it all non-lazy + + if (err != -ECHILD) // hard error + return err; + return inode_permission(idmap, nd->inode, MAY_EXEC); } |