[PATCH] btrfs: fix cannot use the loop device
in [Kernel]
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From: Miao Xie on 6 Jun 2010 23:40 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 <miaox(a)cn.fujitsu.com> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |