diff options
| -rw-r--r-- | fs/autofs4/root.c | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 2296c8301b66..d76d083f2f06 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -433,8 +433,6 @@ static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) /* The daemon never waits. */ if (autofs4_oz_mode(sbi)) { - if (rcu_walk) - return 0; if (!d_mountpoint(dentry)) return -EISDIR; return 0; @@ -452,12 +450,28 @@ static int autofs4_d_manage(struct dentry *dentry, bool rcu_walk) if (status) return status; - if (rcu_walk) - /* it is always safe to return 0 as the worst that - * will happen is we retry in REF-walk mode. - * Better than always taking a lock. + if (rcu_walk) { + /* We don't need fs_lock in rcu_walk mode, + * just testing 'AUTOFS_INFO_NO_RCU' is enough. + * simple_empty() takes a spinlock, so leave it + * to last. + * We only return -EISDIR when certain this isn't + * a mount-trap. */ + struct inode *inode; + if (ino->flags & (AUTOFS_INF_EXPIRING | AUTOFS_INF_NO_RCU)) + return 0; + if (d_mountpoint(dentry)) + return 0; + inode = ACCESS_ONCE(dentry->d_inode); + if (inode && S_ISLNK(inode->i_mode)) + return -EISDIR; + if (list_empty(&dentry->d_subdirs)) + return 0; + if (!simple_empty(dentry)) + return -EISDIR; return 0; + } spin_lock(&sbi->fs_lock); /* |