1 files changed, 79 insertions, 62 deletions

diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index 68495f0de7b3..b905ae37f912 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -1,4 +1,4 @@
-/* mntpt.c: mountpoint management
+/* mountpoint management
  *
  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -18,10 +18,6 @@
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/mnt_namespace.h>
-#include "super.h"
-#include "cell.h"
-#include "volume.h"
-#include "vnode.h"
 #include "internal.h"
 
 
@@ -30,6 +26,7 @@ static struct dentry *afs_mntpt_lookup(struct inode *dir,
                                        struct nameidata *nd);
 static int afs_mntpt_open(struct inode *inode, struct file *file);
 static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd);
+static void afs_mntpt_expiry_timed_out(struct work_struct *work);
 
 const struct file_operations afs_mntpt_file_operations = {
         .open           = afs_mntpt_open,
@@ -43,24 +40,19 @@ const struct inode_operations afs_mntpt_inode_operations = {
 };
 
 static LIST_HEAD(afs_vfsmounts);
+static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out);
 
-static void afs_mntpt_expiry_timed_out(struct afs_timer *timer);
+unsigned long afs_mntpt_expiry_timeout = 10 * 60;
 
-struct afs_timer_ops afs_mntpt_expiry_timer_ops = {
-        .timed_out      = afs_mntpt_expiry_timed_out,
-};
-
-struct afs_timer afs_mntpt_expiry_timer;
-
-unsigned long afs_mntpt_expiry_timeout = 20;
-
-/*****************************************************************************/
 /*
  * check a symbolic link to see whether it actually encodes a mountpoint
  * - sets the AFS_VNODE_MOUNTPOINT flag on the vnode appropriately
  */
-int afs_mntpt_check_symlink(struct afs_vnode *vnode)
+int afs_mntpt_check_symlink(struct afs_vnode *vnode, struct key *key)
 {
+        struct file file = {
+                .private_data = key,
+        };
         struct page *page;
         size_t size;
         char *buf;
@@ -69,7 +61,7 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode)
         _enter("{%u,%u}", vnode->fid.vnode, vnode->fid.unique);
 
         /* read the contents of the symlink into the pagecache */
-        page = read_mapping_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0, NULL);
+        page = read_mapping_page(AFS_VNODE_TO_I(vnode)->i_mapping, 0, &file);
         if (IS_ERR(page)) {
                 ret = PTR_ERR(page);
                 goto out;
@@ -85,7 +77,7 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode)
 
         /* examine the symlink's contents */
         size = vnode->status.size;
-        _debug("symlink to %*.*s", size, (int) size, buf);
+        _debug("symlink to %*.*s", (int) size, (int) size, buf);
 
         if (size > 2 &&
             (buf[0] == '%' || buf[0] == '#') &&
@@ -93,22 +85,20 @@ int afs_mntpt_check_symlink(struct afs_vnode *vnode)
             ) {
                 _debug("symlink is a mountpoint");
                 spin_lock(&vnode->lock);
-                vnode->flags |= AFS_VNODE_MOUNTPOINT;
+                set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
                 spin_unlock(&vnode->lock);
         }
 
         ret = 0;
 
- out_free:
+out_free:
         kunmap(page);
         page_cache_release(page);
- out:
+out:
         _leave(" = %d", ret);
         return ret;
+}
 
-} /* end afs_mntpt_check_symlink() */
-
-/*****************************************************************************/
 /*
  * no valid lookup procedure on this sort of dir
  */
@@ -116,7 +106,7 @@ static struct dentry *afs_mntpt_lookup(struct inode *dir,
                                        struct dentry *dentry,
                                        struct nameidata *nd)
 {
-        kenter("%p,%p{%p{%s},%s}",
+        _enter("%p,%p{%p{%s},%s}",
                dir,
                dentry,
                dentry->d_parent,
@@ -125,15 +115,14 @@ static struct dentry *afs_mntpt_lookup(struct inode *dir,
                dentry->d_name.name);
 
         return ERR_PTR(-EREMOTE);
-} /* end afs_mntpt_lookup() */
+}
 
-/*****************************************************************************/
 /*
  * no valid open procedure on this sort of dir
  */
 static int afs_mntpt_open(struct inode *inode, struct file *file)
 {
-        kenter("%p,%p{%p{%s},%s}",
+        _enter("%p,%p{%p{%s},%s}",
                inode, file,
                file->f_path.dentry->d_parent,
                file->f_path.dentry->d_parent ?
@@ -142,9 +131,8 @@ static int afs_mntpt_open(struct inode *inode, struct file *file)
                file->f_path.dentry->d_name.name);
 
         return -EREMOTE;
-} /* end afs_mntpt_open() */
+}
 
-/*****************************************************************************/
 /*
  * create a vfsmount to be automounted
  */
@@ -157,7 +145,7 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
         char *buf, *devname = NULL, *options = NULL;
         int ret;
 
-        kenter("{%s}", mntpt->d_name.name);
+        _enter("{%s}", mntpt->d_name.name);
 
         BUG_ON(!mntpt->d_inode);
 
@@ -201,79 +189,108 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
                 strcat(options, ",rwpath");
 
         /* try and do the mount */
-        kdebug("--- attempting mount %s -o %s ---", devname, options);
+        _debug("--- attempting mount %s -o %s ---", devname, options);
         mnt = vfs_kern_mount(&afs_fs_type, 0, devname, options);
-        kdebug("--- mount result %p ---", mnt);
+        _debug("--- mount result %p ---", mnt);
 
         free_page((unsigned long) devname);
         free_page((unsigned long) options);
-        kleave(" = %p", mnt);
+        _leave(" = %p", mnt);
         return mnt;
 
- error:
+error:
         if (page)
                 page_cache_release(page);
         if (devname)
                 free_page((unsigned long) devname);
         if (options)
                 free_page((unsigned long) options);
-        kleave(" = %d", ret);
+        _leave(" = %d", ret);
         return ERR_PTR(ret);
-} /* end afs_mntpt_do_automount() */
+}
 
-/*****************************************************************************/
 /*
  * follow a link from a mountpoint directory, thus causing it to be mounted
  */
 static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
         struct vfsmount *newmnt;
-        struct dentry *old_dentry;
         int err;
 
-        kenter("%p{%s},{%s:%p{%s}}",
+        _enter("%p{%s},{%s:%p{%s},}",
                dentry,
                dentry->d_name.name,
                nd->mnt->mnt_devname,
                dentry,
                nd->dentry->d_name.name);
 
-        newmnt = afs_mntpt_do_automount(dentry);
+        dput(nd->dentry);
+        nd->dentry = dget(dentry);
+
+        newmnt = afs_mntpt_do_automount(nd->dentry);
         if (IS_ERR(newmnt)) {
                 path_release(nd);
                 return (void *)newmnt;
         }
 
-        old_dentry = nd->dentry;
-        nd->dentry = dentry;
-        err = do_add_mount(newmnt, nd, 0, &afs_vfsmounts);
-        nd->dentry = old_dentry;
-
-        path_release(nd);
-
-        if (!err) {
-                mntget(newmnt);
+        mntget(newmnt);
+        err = do_add_mount(newmnt, nd, MNT_SHRINKABLE, &afs_vfsmounts);
+        switch (err) {
+        case 0:
+                mntput(nd->mnt);
+                dput(nd->dentry);
                 nd->mnt = newmnt;
-                dget(newmnt->mnt_root);
-                nd->dentry = newmnt->mnt_root;
+                nd->dentry = dget(newmnt->mnt_root);
+                schedule_delayed_work(&afs_mntpt_expiry_timer,
+                                      afs_mntpt_expiry_timeout * HZ);
+                break;
+        case -EBUSY:
+                /* someone else made a mount here whilst we were busy */
+                while (d_mountpoint(nd->dentry) &&
+                       follow_down(&nd->mnt, &nd->dentry))
+                        ;
+                err = 0;
+        default:
+                mntput(newmnt);
+                break;
         }
 
-        kleave(" = %d", err);
+        _leave(" = %d", err);
         return ERR_PTR(err);
-} /* end afs_mntpt_follow_link() */
+}
 
-/*****************************************************************************/
 /*
  * handle mountpoint expiry timer going off
  */
-static void afs_mntpt_expiry_timed_out(struct afs_timer *timer)
+static void afs_mntpt_expiry_timed_out(struct work_struct *work)
 {
-        kenter("");
+        _enter("");
 
-        mark_mounts_for_expiry(&afs_vfsmounts);
+        if (!list_empty(&afs_vfsmounts)) {
+                mark_mounts_for_expiry(&afs_vfsmounts);
+                schedule_delayed_work(&afs_mntpt_expiry_timer,
+                                      afs_mntpt_expiry_timeout * HZ);
+        }
+
+        _leave("");
+}
 
-        afs_kafstimod_add_timer(&afs_mntpt_expiry_timer,
-                                afs_mntpt_expiry_timeout * HZ);
+/*
+ * kill the AFS mountpoint timer if it's still running
+ */
+void afs_mntpt_kill_timer(void)
+{
+        _enter("");
 
-        kleave("");
-} /* end afs_mntpt_expiry_timed_out() */
+        ASSERT(list_empty(&afs_vfsmounts));
+        cancel_delayed_work(&afs_mntpt_expiry_timer);
+        flush_scheduled_work();
+}
+
+/*
+ * begin unmount by attempting to remove all automounted mountpoints we added
+ */
+void afs_umount_begin(struct vfsmount *vfsmnt, int flags)
+{
+        shrink_submounts(vfsmnt, &afs_vfsmounts);
+}