ecryptfs: don't allow mmap when the lower fs doesn't support it

[pandora-kernel.git] / fs / ecryptfs / file.c

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 0747a43..298f5b2 100644 (file)
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -183,6 +183,19 @@ out:
        return rc;
 }
 
+static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma)
+{
+       struct file *lower_file = ecryptfs_file_to_lower(file);
+       /*
+        * Don't allow mmap on top of file systems that don't support it
+        * natively.  If FILESYSTEM_MAX_STACK_DEPTH > 2 or ecryptfs
+        * allows recursive mounting, this will need to be extended.
+        */
+       if (!lower_file->f_op->mmap)
+               return -ENODEV;
+       return generic_file_mmap(file, vma);
+}
+
 /**
  * ecryptfs_open
  * @inode: inode speciying file to open
@@ -196,24 +209,12 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
 {
        int rc = 0;
        struct ecryptfs_crypt_stat *crypt_stat = NULL;
-       struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
        struct dentry *ecryptfs_dentry = file->f_path.dentry;
        /* Private value of ecryptfs_dentry allocated in
         * ecryptfs_lookup() */
        struct dentry *lower_dentry;
        struct ecryptfs_file_info *file_info;
 
-       mount_crypt_stat = &ecryptfs_superblock_to_private(
-               ecryptfs_dentry->d_sb)->mount_crypt_stat;
-       if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
-           && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
-               || (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
-               || (file->f_flags & O_APPEND))) {
-               printk(KERN_WARNING "Mount has encrypted view enabled; "
-                      "files may only be read\n");
-               rc = -EPERM;
-               goto out;
-       }
        /* Released in ecryptfs_release or end of function if failure */
        file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
        ecryptfs_set_file_private(file, file_info);
@@ -276,8 +277,14 @@ out:
 
 static int ecryptfs_flush(struct file *file, fl_owner_t td)
 {
-       return file->f_mode & FMODE_WRITE
-              ? filemap_write_and_wait(file->f_mapping) : 0;
+       struct file *lower_file = ecryptfs_file_to_lower(file);
+
+       if (lower_file->f_op && lower_file->f_op->flush) {
+               filemap_write_and_wait(file->f_mapping);
+               return lower_file->f_op->flush(lower_file, td);
+       }
+
+       return 0;
 }
 
 static int ecryptfs_release(struct inode *inode, struct file *file)
@@ -313,9 +320,23 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
        if (ecryptfs_file_to_private(file))
                lower_file = ecryptfs_file_to_lower(file);
-       if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl)
+       if (!(lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl))
+               return rc;
+
+       switch (cmd) {
+       case FITRIM:
+       case FS_IOC_GETFLAGS:
+       case FS_IOC_SETFLAGS:
+       case FS_IOC_GETVERSION:
+       case FS_IOC_SETVERSION:
                rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
-       return rc;
+               fsstack_copy_attr_all(file->f_path.dentry->d_inode,
+                                     lower_file->f_path.dentry->d_inode);
+
+               return rc;
+       default:
+               return rc;
+       }
 }
 
 #ifdef CONFIG_COMPAT
@@ -327,9 +348,23 @@ ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 
        if (ecryptfs_file_to_private(file))
                lower_file = ecryptfs_file_to_lower(file);
-       if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl)
+       if (!(lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl))
+               return rc;
+
+       switch (cmd) {
+       case FITRIM:
+       case FS_IOC32_GETFLAGS:
+       case FS_IOC32_SETFLAGS:
+       case FS_IOC32_GETVERSION:
+       case FS_IOC32_SETVERSION:
                rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
-       return rc;
+               fsstack_copy_attr_all(file->f_path.dentry->d_inode,
+                                     lower_file->f_path.dentry->d_inode);
+
+               return rc;
+       default:
+               return rc;
+       }
 }
 #endif
 
@@ -360,7 +395,7 @@ const struct file_operations ecryptfs_main_fops = {
 #ifdef CONFIG_COMPAT
        .compat_ioctl = ecryptfs_compat_ioctl,
 #endif
-       .mmap = generic_file_mmap,
+       .mmap = ecryptfs_mmap,
        .open = ecryptfs_open,
        .flush = ecryptfs_flush,
        .release = ecryptfs_release,