afs: Remove the "autocell" mount option

Remove the "autocell" mount option.  It was an attempt to do automounting
of arbitrary cells based on what the user looked up but within the root
directory of a mounted volume.  This isn't really the right thing to do,
and using the "dyn" mount option to get the dynamic root is the right way
to do it.  The kafs-client package uses "-o dyn" when mounting /afs, so it
should be safe to drop "-o autocell".

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20250224234154.2014840-7-dhowells@redhat.com/ # v1
Link: https://lore.kernel.org/r/20250310094206.801057-3-dhowells@redhat.com/ # v4

Author: dhowells

fs/afs/dir.c

@@ -1004,9 +1004,8 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 	afs_stat_v(dvnode, n_lookup);
 	inode = afs_do_lookup(dir, dentry);
 	if (inode == ERR_PTR(-ENOENT))
-		inode = afs_try_auto_mntpt(dentry, dir);
-
-	if (!IS_ERR_OR_NULL(inode))
+		inode = NULL;
+	else if (!IS_ERR_OR_NULL(inode))
 		fid = AFS_FS_I(inode)->fid;
 
 	_debug("splice %p", dentry->d_inode);

fs/afs/dynroot.c

@@ -155,7 +155,7 @@ static int afs_probe_cell_name(struct dentry *dentry)
  * Try to auto mount the mountpoint with pseudo directory, if the autocell
  * operation is setted.
  */
-struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir)
+static struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir)
 {
 	struct afs_vnode *vnode = AFS_FS_I(dir);
 	struct inode *inode;
@@ -164,9 +164,6 @@ struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir)
 	_enter("%p{%pd}, {%llx:%llu}",
 	       dentry, dentry, vnode->fid.vid, vnode->fid.vnode);
 
-	if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
-		goto out;
-
 	ret = afs_probe_cell_name(dentry);
 	if (ret < 0)
 		goto out;

fs/afs/internal.h

@@ -700,7 +700,6 @@ struct afs_vnode {
 #define AFS_VNODE_ZAP_DATA	3		/* set if vnode's data should be invalidated */
 #define AFS_VNODE_DELETED	4		/* set if vnode deleted on server */
 #define AFS_VNODE_MOUNTPOINT	5		/* set if vnode is a mountpoint symlink */
-#define AFS_VNODE_AUTOCELL	6		/* set if Vnode is an auto mount point */
 #define AFS_VNODE_PSEUDODIR	7 		/* set if Vnode is a pseudo directory */
 #define AFS_VNODE_NEW_CONTENT	8		/* Set if file has new content (create/trunc-0) */
 #define AFS_VNODE_SILLY_DELETED	9		/* Set if file has been silly-deleted */
@@ -1111,7 +1110,6 @@ extern int afs_silly_iput(struct dentry *, struct inode *);
 extern const struct inode_operations afs_dynroot_inode_operations;
 extern const struct dentry_operations afs_dynroot_dentry_operations;
 
-extern struct inode *afs_try_auto_mntpt(struct dentry *, struct inode *);
 extern int afs_dynroot_mkdir(struct afs_net *, struct afs_cell *);
 extern void afs_dynroot_rmdir(struct afs_net *, struct afs_cell *);
 extern int afs_dynroot_populate(struct super_block *);

fs/afs/super.c

@@ -194,8 +194,6 @@ static int afs_show_options(struct seq_file *m, struct dentry *root)
 
 	if (as->dyn_root)
 		seq_puts(m, ",dyn");
-	if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
-		seq_puts(m, ",autocell");
 	switch (as->flock_mode) {
 	case afs_flock_mode_unset:	break;
 	case afs_flock_mode_local:	p = "local";	break;
@@ -478,9 +476,6 @@ static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
 	if (IS_ERR(inode))
 		return PTR_ERR(inode);
 
-	if (ctx->autocell || as->dyn_root)
-		set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
-
 	ret = -ENOMEM;
 	sb->s_root = d_make_root(inode);
 	if (!sb->s_root)