[PATCH] autofs4: follow_link missing functionality

This functionality is also need for operation of autofs v5 direct mounts.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 44 insertions, 10 deletions

diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 08e33218a64a..b8ce02607d66 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -113,10 +113,6 @@ static int autofs4_direct_busy(struct vfsmount *mnt,
         DPRINTK("top %p %.*s",
                 top, (int) top->d_name.len, top->d_name.name);
 
-        /* Not a mountpoint - give up */
-        if (!d_mountpoint(top))
-                return 1;
-
         /* If it's busy update the expiry counters */
         if (!may_umount_tree(mnt)) {
                 struct autofs_info *ino = autofs4_dentry_ino(top);
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 3f0048582248..c8fe43a475e2 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -57,6 +57,9 @@ struct inode_operations autofs4_indirect_root_inode_operations = {
 
 struct inode_operations autofs4_direct_root_inode_operations = {
         .lookup         = autofs4_lookup,
+        .unlink         = autofs4_dir_unlink,
+        .mkdir          = autofs4_dir_mkdir,
+        .rmdir          = autofs4_dir_rmdir,
         .follow_link    = autofs4_follow_link,
 };
 
@@ -337,15 +340,50 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
         if (oz_mode || !lookup_type)
                 goto done;
 
-        status = try_to_fill_dentry(dentry, 0);
-        if (status)
-                goto out_error;
+        /*
+         * If a request is pending wait for it.
+         * If it's a mount then it won't be expired till at least
+         * a liitle later and if it's an expire then we might need
+         * to mount it again.
+         */
+        if (autofs4_ispending(dentry)) {
+                DPRINTK("waiting for active request %p name=%.*s",
+                        dentry, dentry->d_name.len, dentry->d_name.name);
 
-        if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
-                status = -ENOENT;
-                goto out_error;
+                status = autofs4_wait(sbi, dentry, NFY_NONE);
+
+                DPRINTK("request done status=%d", status);
         }
 
+        /*
+         * If the dentry contains directories then it is an
+         * autofs multi-mount with no root mount offset. So
+         * don't try to mount it again.
+         */
+        spin_lock(&dcache_lock);
+        if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
+                spin_unlock(&dcache_lock);
+
+                status = try_to_fill_dentry(dentry, 0);
+                if (status)
+                        goto out_error;
+
+                /*
+                 * The mount succeeded but if there is no root mount
+                 * it must be an autofs multi-mount with no root offset
+                 * so we don't need to follow the mount.
+                 */
+                if (d_mountpoint(dentry)) {
+                        if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
+                                status = -ENOENT;
+                                goto out_error;
+                        }
+                }
+
+                goto done;
+        }
+        spin_unlock(&dcache_lock);
+
 done:
         return NULL;