[PATCH] autofs4: add v5 follow_link mount trigger method

This patch adds a follow_link inode method for the root of an autofs direct
mount trigger.  It also adds the corresponding mount options and updates the
show_mount method.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 43 insertions, 9 deletions

diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c
index d9a71dab40fc..3801bed94e45 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -3,6 +3,7 @@
  * linux/fs/autofs/inode.c
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *  Copyright 2005-2006 Ian Kent <raven@themaw.net>
  *
  * This file is part of the Linux kernel and is made available under
  * the terms of the GNU General Public License, version 2, or at your
@@ -177,6 +178,13 @@ static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
         seq_printf(m, ",minproto=%d", sbi->min_proto);
         seq_printf(m, ",maxproto=%d", sbi->max_proto);
 
+        if (sbi->type & AUTOFS_TYP_OFFSET)
+                seq_printf(m, ",offset");
+        else if (sbi->type & AUTOFS_TYP_DIRECT)
+                seq_printf(m, ",direct");
+        else
+                seq_printf(m, ",indirect");
+
         return 0;
 }
 
@@ -186,7 +194,8 @@ static struct super_operations autofs4_sops = {
         .show_options   = autofs4_show_options,
 };
 
-enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto};
+enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
+        Opt_indirect, Opt_direct, Opt_offset};
 
 static match_table_t tokens = {
         {Opt_fd, "fd=%u"},
@@ -195,11 +204,15 @@ static match_table_t tokens = {
         {Opt_pgrp, "pgrp=%u"},
         {Opt_minproto, "minproto=%u"},
         {Opt_maxproto, "maxproto=%u"},
+        {Opt_indirect, "indirect"},
+        {Opt_direct, "direct"},
+        {Opt_offset, "offset"},
         {Opt_err, NULL}
 };
 
 static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
-                         pid_t *pgrp, int *minproto, int *maxproto)
+                         pid_t *pgrp, unsigned int *type,
+                         int *minproto, int *maxproto)
 {
         char *p;
         substring_t args[MAX_OPT_ARGS];
@@ -253,6 +266,15 @@ static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
                                 return 1;
                         *maxproto = option;
                         break;
+                case Opt_indirect:
+                        *type = AUTOFS_TYP_INDIRECT;
+                        break;
+                case Opt_direct:
+                        *type = AUTOFS_TYP_DIRECT;
+                        break;
+                case Opt_offset:
+                        *type = AUTOFS_TYP_DIRECT | AUTOFS_TYP_OFFSET;
+                        break;
                 default:
                         return 1;
                 }
@@ -271,6 +293,11 @@ static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
         return ino;
 }
 
+void autofs4_dentry_release(struct dentry *);
+static struct dentry_operations autofs4_sb_dentry_operations = {
+        .d_release      = autofs4_dentry_release,
+};
+
 int autofs4_fill_super(struct super_block *s, void *data, int silent)
 {
         struct inode * root_inode;
@@ -297,6 +324,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
         sbi->sb = s;
         sbi->version = 0;
         sbi->sub_version = 0;
+        sbi->type = 0;
         sbi->min_proto = 0;
         sbi->max_proto = 0;
         mutex_init(&sbi->wq_mutex);
@@ -315,27 +343,31 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
         if (!ino)
                 goto fail_free;
         root_inode = autofs4_get_inode(s, ino);
-        kfree(ino);
         if (!root_inode)
-                goto fail_free;
+                goto fail_ino;
 
-        root_inode->i_op = &autofs4_root_inode_operations;
-        root_inode->i_fop = &autofs4_root_operations;
         root = d_alloc_root(root_inode);
-        pipe = NULL;
-
         if (!root)
                 goto fail_iput;
+        pipe = NULL;
+
+        root->d_op = &autofs4_sb_dentry_operations;
+        root->d_fsdata = ino;
 
         /* Can this call block? */
         if (parse_options(data, &pipefd,
                           &root_inode->i_uid, &root_inode->i_gid,
-                          &sbi->oz_pgrp,
+                          &sbi->oz_pgrp, &sbi->type,
                           &sbi->min_proto, &sbi->max_proto)) {
                 printk("autofs: called with bogus options\n");
                 goto fail_dput;
         }
 
+        root_inode->i_fop = &autofs4_root_operations;
+        root_inode->i_op = sbi->type & AUTOFS_TYP_DIRECT ?
+                        &autofs4_direct_root_inode_operations :
+                        &autofs4_indirect_root_inode_operations;
+
         /* Couldn't this be tested earlier? */
         if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
             sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
@@ -391,6 +423,8 @@ fail_dput:
 fail_iput:
         printk("autofs: get root dentry failed\n");
         iput(root_inode);
+fail_ino:
+        kfree(ino);
 fail_free:
         kfree(sbi);
 fail_unlock: