From 25e195aa1e607f129ab912d29fcfc79239703307 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 11 Jan 2020 11:27:46 -0500 Subject: [PATCH] follow_automount(): get rid of dead^Wstillborn code 1) no instances of ->d_automount() have ever made use of the "return ERR_PTR(-EISDIR) if you don't feel like mounting anything" - that's a rudiment of plans that got superseded before the thing went into the tree. Despite the comment in follow_automount(), autofs has never done that. 2) if there's no ->d_automount() in dentry_operations, filesystems should not set DCACHE_NEED_AUTOMOUNT in the first place. None have ever done so... Signed-off-by: Al Viro --- fs/namei.c | 28 +++------------------------- fs/namespace.c | 9 ++++++++- 2 files changed, 11 insertions(+), 26 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 626eddb33508..39dd56f5171f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1210,10 +1210,7 @@ EXPORT_SYMBOL(follow_up); */ static int follow_automount(struct path *path, struct nameidata *nd) { - struct vfsmount *mnt; - - if (!path->dentry->d_op || !path->dentry->d_op->d_automount) - return -EREMOTE; + struct dentry *dentry = path->dentry; /* We don't want to mount if someone's just doing a stat - * unless they're stat'ing a directory and appended a '/' to @@ -1228,33 +1225,14 @@ static int follow_automount(struct path *path, struct nameidata *nd) */ if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY | LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) && - path->dentry->d_inode) + dentry->d_inode) return -EISDIR; nd->total_link_count++; if (nd->total_link_count >= 40) return -ELOOP; - mnt = path->dentry->d_op->d_automount(path); - if (IS_ERR(mnt)) { - /* - * The filesystem is allowed to return -EISDIR here to indicate - * it doesn't want to automount. For instance, autofs would do - * this so that its userspace daemon can mount on this dentry. - * - * However, we can only permit this if it's a terminal point in - * the path being looked up; if it wasn't then the remainder of - * the path is inaccessible and we should say so. - */ - if (PTR_ERR(mnt) == -EISDIR && (nd->flags & LOOKUP_PARENT)) - return -EREMOTE; - return PTR_ERR(mnt); - } - - if (!mnt) - return 0; - - return finish_automount(mnt, path); + return finish_automount(dentry->d_op->d_automount(path), path); } /* diff --git a/fs/namespace.c b/fs/namespace.c index 777c3116e62e..743980380a8f 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2824,9 +2824,16 @@ static int do_new_mount(struct path *path, const char *fstype, int sb_flags, int finish_automount(struct vfsmount *m, struct path *path) { struct dentry *dentry = path->dentry; - struct mount *mnt = real_mount(m); struct mountpoint *mp; + struct mount *mnt; int err; + + if (!m) + return 0; + if (IS_ERR(m)) + return PTR_ERR(m); + + mnt = real_mount(m); /* The new mount record should have at least 2 refs to prevent it being * expired before we get a chance to add it */