diff options
| -rw-r--r-- | fs/dcache.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 25131f105a60..ddc5ee49694d 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2300,11 +2300,20 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent, seq = raw_seqcount_begin(&dentry->d_seq); if (dentry->d_parent != parent) continue; - if (d_unhashed(dentry)) - continue; if (dentry->d_name.hash_len != hashlen) continue; - if (dentry_cmp(dentry, str, hashlen_len(hashlen)) != 0) + if (unlikely(dentry_cmp(dentry, str, hashlen_len(hashlen)) != 0)) + continue; + /* + * Check for the dentry being unhashed. + * + * As tempting as it is, we *can't* skip it because of a race window + * between us finding the dentry before it gets unhashed and loading + * the sequence counter after unhashing is finished. + * + * We can at least predict on it. + */ + if (unlikely(d_unhashed(dentry))) continue; *seqp = seq; return dentry; |