From mboxrd@z Thu Jan 1 00:00:00 1970 From: Miao Xie Subject: [PATCH] btrfs: fix cannot use the loop device Date: Mon, 07 Jun 2010 11:38:51 +0800 Message-ID: <4C0C69CB.2070104@cn.fujitsu.com> Reply-To: miaox@cn.fujitsu.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Linux Btrfs , Linux-Kernel To: Chris Mason Return-path: List-ID: we cannot use the loop device which has been connected to a file in the btrf The reproduce steps is following: # dd if=/dev/zero of=vdev0 bs=1M count=1024 # losetup /dev/loop0 vdev0 # mkfs.btrfs /dev/loop0 ... failed to zero device start -5 The reason is that the btrfs don't implement either ->write_begin or ->write the VFS API, so we fix it by setting ->write to do_sync_write(). Signed-off-by: Miao Xie --- fs/btrfs/file.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 79437c5..abcb918 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1197,6 +1197,7 @@ static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) const struct file_operations btrfs_file_operations = { .llseek = generic_file_llseek, .read = do_sync_read, + .write = do_sync_write, .aio_read = generic_file_aio_read, .splice_read = generic_file_splice_read, .aio_write = btrfs_file_aio_write, -- 1.6.5.2