ecryptfs: pass matching flags to interpose as defined and used there

[safe/jmp/linux-2.6] / fs / namespace.c

diff --git a/fs/namespace.c b/fs/namespace.c
index 3dc283f..c768f73 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -22,6 +22,7 @@
 #include <linux/seq_file.h>
 #include <linux/mnt_namespace.h>
 #include <linux/namei.h>
+#include <linux/nsproxy.h>
 #include <linux/security.h>
 #include <linux/mount.h>
 #include <linux/ramfs.h>
@@ -315,7 +316,8 @@ EXPORT_SYMBOL_GPL(mnt_clone_write);
  */
 int mnt_want_write_file(struct file *file)
 {
-       if (!(file->f_mode & FMODE_WRITE))
+       struct inode *inode = file->f_dentry->d_inode;
+       if (!(file->f_mode & FMODE_WRITE) || special_file(inode->i_mode))
                return mnt_want_write(file->f_path.mnt);
        else
                return mnt_clone_write(file->f_path.mnt);
@@ -963,10 +965,12 @@ EXPORT_SYMBOL(may_umount_tree);
 int may_umount(struct vfsmount *mnt)
 {
        int ret = 1;
+       down_read(&namespace_sem);
        spin_lock(&vfsmount_lock);
        if (propagate_mount_busy(mnt, 2))
                ret = 0;
        spin_unlock(&vfsmount_lock);
+       up_read(&namespace_sem);
        return ret;
 }
 
@@ -1350,12 +1354,12 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt,
        if (err)
                goto out_cleanup_ids;
 
+       spin_lock(&vfsmount_lock);
+
        if (IS_MNT_SHARED(dest_mnt)) {
                for (p = source_mnt; p; p = next_mnt(p, source_mnt))
                        set_mnt_shared(p);
        }
-
-       spin_lock(&vfsmount_lock);
        if (parent_path) {
                detach_mnt(source_mnt, parent_path);
                attach_mnt(source_mnt, path);
@@ -1532,8 +1536,12 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
                err = change_mount_flags(path->mnt, flags);
        else
                err = do_remount_sb(sb, flags, data, 0);
-       if (!err)
+       if (!err) {
+               spin_lock(&vfsmount_lock);
+               mnt_flags |= path->mnt->mnt_flags & MNT_PNODE_MASK;
                path->mnt->mnt_flags = mnt_flags;
+               spin_unlock(&vfsmount_lock);
+       }
        up_write(&sb->s_umount);
        if (!err) {
                security_sb_post_remount(path->mnt, flags, data);
@@ -1638,7 +1646,7 @@ static int do_new_mount(struct path *path, char *type, int flags,
 {
        struct vfsmount *mnt;
 
-       if (!type || !memchr(type, 0, PAGE_SIZE))
+       if (!type)
                return -EINVAL;
 
        /* we need capabilities... */
@@ -1663,6 +1671,8 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path,
 {
        int err;
 
+       mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD);
+
        down_write(&namespace_sem);
        /* Something was mounted here while we slept */
        while (d_mountpoint(path->dentry) &&
@@ -1869,6 +1879,23 @@ int copy_mount_options(const void __user * data, unsigned long *where)
        return 0;
 }
 
+int copy_mount_string(const void __user *data, char **where)
+{
+       char *tmp;
+
+       if (!data) {
+               *where = NULL;
+               return 0;
+       }
+
+       tmp = strndup_user(data, PAGE_SIZE);
+       if (IS_ERR(tmp))
+               return PTR_ERR(tmp);
+
+       *where = tmp;
+       return 0;
+}
+
 /*
  * Flags is a 32-bit value that allows up to 31 non-fs dependent flags to
  * be given to the mount() call (ie: read-only, no-dev, no-suid etc).
@@ -1898,12 +1925,20 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
 
        if (!dir_name || !*dir_name || !memchr(dir_name, 0, PAGE_SIZE))
                return -EINVAL;
-       if (dev_name && !memchr(dev_name, 0, PAGE_SIZE))
-               return -EINVAL;
 
        if (data_page)
                ((char *)data_page)[PAGE_SIZE - 1] = 0;
 
+       /* ... and get the mountpoint */
+       retval = kern_path(dir_name, LOOKUP_FOLLOW, &path);
+       if (retval)
+               return retval;
+
+       retval = security_sb_mount(dev_name, &path,
+                                  type_page, flags, data_page);
+       if (retval)
+               goto dput_out;
+
        /* Default to relatime unless overriden */
        if (!(flags & MS_NOATIME))
                mnt_flags |= MNT_RELATIME;
@@ -1928,16 +1963,6 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
                   MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT |
                   MS_STRICTATIME);
 
-       /* ... and get the mountpoint */
-       retval = kern_path(dir_name, LOOKUP_FOLLOW, &path);
-       if (retval)
-               return retval;
-
-       retval = security_sb_mount(dev_name, &path,
-                                  type_page, flags, data_page);
-       if (retval)
-               goto dput_out;
-
        if (flags & MS_REMOUNT)
                retval = do_remount(&path, flags & ~MS_REMOUNT, mnt_flags,
                                    data_page);
@@ -2068,40 +2093,42 @@ EXPORT_SYMBOL(create_mnt_ns);
 SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
                char __user *, type, unsigned long, flags, void __user *, data)
 {
-       int retval;
+       int ret;
+       char *kernel_type;
+       char *kernel_dir;
+       char *kernel_dev;
        unsigned long data_page;
-       unsigned long type_page;
-       unsigned long dev_page;
-       char *dir_page;
 
-       retval = copy_mount_options(type, &type_page);
-       if (retval < 0)
-               return retval;
+       ret = copy_mount_string(type, &kernel_type);
+       if (ret < 0)
+               goto out_type;
 
-       dir_page = getname(dir_name);
-       retval = PTR_ERR(dir_page);
-       if (IS_ERR(dir_page))
-               goto out1;
+       kernel_dir = getname(dir_name);
+       if (IS_ERR(kernel_dir)) {
+               ret = PTR_ERR(kernel_dir);
+               goto out_dir;
+       }
 
-       retval = copy_mount_options(dev_name, &dev_page);
-       if (retval < 0)
-               goto out2;
+       ret = copy_mount_string(dev_name, &kernel_dev);
+       if (ret < 0)
+               goto out_dev;
 
-       retval = copy_mount_options(data, &data_page);
-       if (retval < 0)
-               goto out3;
+       ret = copy_mount_options(data, &data_page);
+       if (ret < 0)
+               goto out_data;
 
-       retval = do_mount((char *)dev_page, dir_page, (char *)type_page,
-                         flags, (void *)data_page);
-       free_page(data_page);
+       ret = do_mount(kernel_dev, kernel_dir, kernel_type, flags,
+               (void *) data_page);
 
-out3:
-       free_page(dev_page);
-out2:
-       putname(dir_page);
-out1:
-       free_page(type_page);
-       return retval;
+       free_page(data_page);
+out_data:
+       kfree(kernel_dev);
+out_dev:
+       putname(kernel_dir);
+out_dir:
+       kfree(kernel_type);
+out_type:
+       return ret;
 }
 
 /*