try_lookup_one_len() is identical to lookup_one_unlocked() except that it doesn't include the call to lookup_slow(). The latter doesn't need the inode to be locked, so the former cannot either. So fix the documentation, remove the WARN_ON and fix the only caller to not take the lock. Signed-off-by: NeilBrown <neilb@xxxxxxx> --- Note that in current upstream fs/afs/dynroot.c also contains a call to try_lookup_one_len() with unnecessary locking. However vfs-6.15.shared.afs contains a patch which removes that call, so I didn't bother addressing it here. NeilBrown fs/autofs/dev-ioctl.c | 3 --- fs/namei.c | 5 ++--- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/fs/autofs/dev-ioctl.c b/fs/autofs/dev-ioctl.c index 6d57efbb8110..c5a6aae12d2c 100644 --- a/fs/autofs/dev-ioctl.c +++ b/fs/autofs/dev-ioctl.c @@ -442,7 +442,6 @@ static int autofs_dev_ioctl_timeout(struct file *fp, sbi->exp_timeout = timeout * HZ; } else { struct dentry *base = fp->f_path.dentry; - struct inode *inode = base->d_inode; int path_len = param->size - AUTOFS_DEV_IOCTL_SIZE - 1; struct dentry *dentry; struct autofs_info *ino; @@ -460,9 +459,7 @@ static int autofs_dev_ioctl_timeout(struct file *fp, "the parent autofs mount timeout which could " "prevent shutdown\n"); - inode_lock_shared(inode); dentry = try_lookup_one_len(param->path, base, path_len); - inode_unlock_shared(inode); if (IS_ERR_OR_NULL(dentry)) return dentry ? PTR_ERR(dentry) : -ENOENT; ino = autofs_dentry_ino(dentry); diff --git a/fs/namei.c b/fs/namei.c index ecb7b95c2ca3..c6cef0af0625 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2863,15 +2863,14 @@ static int lookup_one_common(struct mnt_idmap *idmap, * Note that this routine is purely a helper for filesystem usage and should * not be called by generic code. * - * The caller must hold base->i_mutex. + * No locks need be held - only a counted reference to @base is needed. + * */ struct dentry *try_lookup_one_len(const char *name, struct dentry *base, int len) { struct qstr this; int err; - WARN_ON_ONCE(!inode_is_locked(base->d_inode)); - err = lookup_one_common(&nop_mnt_idmap, name, base, len, &this); if (err) return ERR_PTR(err); -- 2.48.1