Re: [RFC][PATCH 05/11] add generic checkpoint f_op to ext fses

[Oren Laadan <orenl@cs.columbia.edu>]

Note that as far as I understand, ext4 does _not_ support a "relink"
operation. By "re-link" I mean an operation that re-links an (orphan)
inode to a filename.  (By "orphan" I mean a file that was opened and
unlinked, so it does not appear in any directory anymore).

This feature is very useful to efficiently checkpoint unlinked files.

Oren.


Dave Hansen wrote:
> This marks ext[234] as being checkpointable.  There will be many
> more to do this to, but this is a start.
> 
> Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
> ---
> 
>  linux-2.6.git-dave/fs/ext2/dir.c  |    1 +
>  linux-2.6.git-dave/fs/ext2/file.c |    2 ++
>  linux-2.6.git-dave/fs/ext3/dir.c  |    1 +
>  linux-2.6.git-dave/fs/ext3/file.c |    1 +
>  linux-2.6.git-dave/fs/ext4/dir.c  |    1 +
>  linux-2.6.git-dave/fs/ext4/file.c |    1 +
>  6 files changed, 7 insertions(+)
> 
> diff -puN fs/ext2/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext2/dir.c
> --- linux-2.6.git/fs/ext2/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext2/dir.c	2009-03-05 08:37:01.000000000 -0800
> @@ -721,4 +721,5 @@ const struct file_operations ext2_dir_op
>  	.compat_ioctl	= ext2_compat_ioctl,
>  #endif
>  	.fsync		= ext2_sync_file,
> +	.checkpoint	= generic_file_checkpoint,
>  };
> diff -puN fs/ext2/file.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext2/file.c
> --- linux-2.6.git/fs/ext2/file.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext2/file.c	2009-03-05 08:37:01.000000000 -0800
> @@ -58,6 +58,7 @@ const struct file_operations ext2_file_o
>  	.fsync		= ext2_sync_file,
>  	.splice_read	= generic_file_splice_read,
>  	.splice_write	= generic_file_splice_write,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  
>  #ifdef CONFIG_EXT2_FS_XIP
> @@ -73,6 +74,7 @@ const struct file_operations ext2_xip_fi
>  	.open		= generic_file_open,
>  	.release	= ext2_release_file,
>  	.fsync		= ext2_sync_file,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  #endif
>  
> diff -puN fs/ext3/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext3/dir.c
> --- linux-2.6.git/fs/ext3/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext3/dir.c	2009-03-05 08:37:01.000000000 -0800
> @@ -48,6 +48,7 @@ const struct file_operations ext3_dir_op
>  #endif
>  	.fsync		= ext3_sync_file,	/* BKL held */
>  	.release	= ext3_release_dir,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  
>  
> diff -puN fs/ext3/file.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext3/file.c
> --- linux-2.6.git/fs/ext3/file.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext3/file.c	2009-03-05 08:37:01.000000000 -0800
> @@ -122,6 +122,7 @@ const struct file_operations ext3_file_o
>  	.fsync		= ext3_sync_file,
>  	.splice_read	= generic_file_splice_read,
>  	.splice_write	= generic_file_splice_write,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  
>  const struct inode_operations ext3_file_inode_operations = {
> diff -puN fs/ext4/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext4/dir.c
> --- linux-2.6.git/fs/ext4/dir.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext4/dir.c	2009-03-05 08:37:01.000000000 -0800
> @@ -48,6 +48,7 @@ const struct file_operations ext4_dir_op
>  #endif
>  	.fsync		= ext4_sync_file,
>  	.release	= ext4_release_dir,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  
>  
> diff -puN fs/ext4/file.c~add-stupid-checkpoint-to-lots-of-fses-take0 fs/ext4/file.c
> --- linux-2.6.git/fs/ext4/file.c~add-stupid-checkpoint-to-lots-of-fses-take0	2009-03-05 08:37:01.000000000 -0800
> +++ linux-2.6.git-dave/fs/ext4/file.c	2009-03-05 08:37:01.000000000 -0800
> @@ -156,6 +156,7 @@ const struct file_operations ext4_file_o
>  	.fsync		= ext4_sync_file,
>  	.splice_read	= generic_file_splice_read,
>  	.splice_write	= generic_file_splice_write,
> +	.checkpoint	= generic_file_checkpoint,
>  };
>  
>  const struct inode_operations ext4_file_inode_operations = {
> _
>