[C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems

[C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems

[Oren Laadan]

From: Matt Helsley <matthltc@us.ibm.com>

These patches extend the use of the generic file checkpoint operation to
non-extX filesystems which have lseek operations that ensure we can save
and restore the files for later use. Note that this does not include
things like FUSE, network filesystems, or pseudo-filesystem kernel
interfaces.

Only compile and boot tested (on x86-32).

[Oren Laadan] Folded patch series into a single patch; original post
included 36 separate patches for individual filesystems:

  [PATCH 01/36] Add the checkpoint operation for affs files and directories.
  [PATCH 02/36] Add the checkpoint operation for befs directories.
  [PATCH 03/36] Add the checkpoint operation for bfs files and directories.
  [PATCH 04/36] Add the checkpoint operation for btrfs files and directories.
  [PATCH 05/36] Add the checkpoint operation for cramfs directories.
  [PATCH 06/36] Add the checkpoint operation for ecryptfs files and directories.
  [PATCH 07/36] Add the checkpoint operation for fat files and directories.
  [PATCH 08/36] Add the checkpoint operation for freevxfs directories.
  [PATCH 09/36] Add the checkpoint operation for hfs files and directories.
  [PATCH 10/36] Add the checkpoint operation for hfsplus files and directories.
  [PATCH 11/36] Add the checkpoint operation for hpfs files and directories.
  [PATCH 12/36] Add the checkpoint operation for hppfs files and directories.
  [PATCH 13/36] Add the checkpoint operation for iso directories.
  [PATCH 14/36] Add the checkpoint operation for jffs2 files and directories.
  [PATCH 15/36] Add the checkpoint operation for jfs files and directories.
  [PATCH 16/36] Add the checkpoint operation for regular nfs files and directories. Skip the various /proc files for now.
  [PATCH 17/36] Add the checkpoint operation for ntfs directories.
  [PATCH 18/36] Add the checkpoint operation for openromfs directories. Explicitly skip the properties for now.
  [PATCH 19/36] Add the checkpoint operation for qnx4 files and directories.
  [PATCH 20/36] Add the checkpoint operation for reiserfs files and directories.
  [PATCH 21/36] Add the checkpoint operation for romfs directories.
  [PATCH 22/36] Add the checkpoint operation for squashfs directories.
  [PATCH 23/36] Add the checkpoint operation for sysv filesystem files and directories.
  [PATCH 24/36] Add the checkpoint operation for ubifs files and directories.
  [PATCH 25/36] Add the checkpoint operation for udf filesystem files and directories.
  [PATCH 26/36] Add the checkpoint operation for xfs files and directories.
  [PATCH 27/36] Add checkpoint operation for efs directories.
  [PATCH 28/36] Add the checkpoint operation for generic, read-only files. At present, some/all files of the following filesystems use this generic definition:
  [PATCH 29/36] Add checkpoint operation for minix filesystem files and directories.
  [PATCH 30/36] Add checkpoint operations for omfs files and directories.
  [PATCH 31/36] Add checkpoint operations for ufs files and directories.
  [PATCH 32/36] Add checkpoint operations for ramfs files. NOTE: since simple_dir_operations are shared between multiple filesystems including ramfs, it's not currently possible to checkpoint open ramfs directories.
  [PATCH 33/36] Add the checkpoint operation for adfs files and directories.
  [PATCH 34/36] Add the checkpoint operation to exofs files and directories.
  [PATCH 35/36] Add the checkpoint operation to nilfs2 files and directories.
  [PATCH 36/36] Add checkpoint operations for UML host filesystem files and directories.

Changelog[v19-rc3]:
  - [Suka] Enable C/R while executing over NFS

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Oren Laadan <orenl@cs.columbia.edu>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: linux-fsdevel@vger.kernel.org
---
 fs/adfs/dir.c               |    1 +
 fs/adfs/file.c              |    1 +
 fs/affs/dir.c               |    1 +
 fs/affs/file.c              |    1 +
 fs/befs/linuxvfs.c          |    1 +
 fs/bfs/dir.c                |    1 +
 fs/bfs/file.c               |    1 +
 fs/btrfs/file.c             |    1 +
 fs/btrfs/inode.c            |    1 +
 fs/btrfs/super.c            |    1 +
 fs/cramfs/inode.c           |    1 +
 fs/ecryptfs/file.c          |    2 ++
 fs/ecryptfs/miscdev.c       |    1 +
 fs/efs/dir.c                |    1 +
 fs/exofs/dir.c              |    1 +
 fs/exofs/file.c             |    1 +
 fs/fat/dir.c                |    1 +
 fs/fat/file.c               |    1 +
 fs/freevxfs/vxfs_lookup.c   |    1 +
 fs/hfs/dir.c                |    1 +
 fs/hfs/inode.c              |    1 +
 fs/hfsplus/dir.c            |    1 +
 fs/hfsplus/inode.c          |    1 +
 fs/hostfs/hostfs_kern.c     |    2 ++
 fs/hpfs/dir.c               |    1 +
 fs/hpfs/file.c              |    1 +
 fs/hppfs/hppfs.c            |    2 ++
 fs/isofs/dir.c              |    1 +
 fs/jffs2/dir.c              |    1 +
 fs/jffs2/file.c             |    1 +
 fs/jfs/file.c               |    1 +
 fs/jfs/namei.c              |    1 +
 fs/minix/dir.c              |    1 +
 fs/minix/file.c             |    1 +
 fs/nfs/dir.c                |    1 +
 fs/nfs/file.c               |    4 ++++
 fs/nilfs2/dir.c             |    2 +-
 fs/nilfs2/file.c            |    1 +
 fs/ntfs/dir.c               |    1 +
 fs/ntfs/file.c              |    3 ++-
 fs/omfs/dir.c               |    1 +
 fs/omfs/file.c              |    1 +
 fs/openpromfs/inode.c       |    2 ++
 fs/qnx4/dir.c               |    1 +
 fs/ramfs/file-mmu.c         |    1 +
 fs/ramfs/file-nommu.c       |    1 +
 fs/read_write.c             |    1 +
 fs/reiserfs/dir.c           |    1 +
 fs/reiserfs/file.c          |    1 +
 fs/romfs/mmap-nommu.c       |    1 +
 fs/romfs/super.c            |    1 +
 fs/squashfs/dir.c           |    3 ++-
 fs/sysv/dir.c               |    1 +
 fs/sysv/file.c              |    1 +
 fs/ubifs/debug.c            |    1 +
 fs/ubifs/dir.c              |    1 +
 fs/ubifs/file.c             |    1 +
 fs/udf/dir.c                |    1 +
 fs/udf/file.c               |    1 +
 fs/ufs/dir.c                |    1 +
 fs/ufs/file.c               |    1 +
 fs/xfs/linux-2.6/xfs_file.c |    2 ++
 62 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index 23aa52f..7106f32 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -198,6 +198,7 @@ const struct file_operations adfs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.readdir	= adfs_readdir,
 	.fsync		= simple_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int
diff --git a/fs/adfs/file.c b/fs/adfs/file.c
index 005ea34..97bd298 100644
--- a/fs/adfs/file.c
+++ b/fs/adfs/file.c
@@ -30,6 +30,7 @@ const struct file_operations adfs_file_operations = {
 	.write		= do_sync_write,
 	.aio_write	= generic_file_aio_write,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations adfs_file_inode_operations = {
diff --git a/fs/affs/dir.c b/fs/affs/dir.c
index 8ca8f3a..6cc5e43 100644
--- a/fs/affs/dir.c
+++ b/fs/affs/dir.c
@@ -22,6 +22,7 @@ const struct file_operations affs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.readdir	= affs_readdir,
 	.fsync		= affs_file_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 /*
diff --git a/fs/affs/file.c b/fs/affs/file.c
index 184e55c..d580a12 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -36,6 +36,7 @@ const struct file_operations affs_file_operations = {
 	.release	= affs_file_release,
 	.fsync		= affs_file_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations affs_file_inode_operations = {
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 34ddda8..b97f79b 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -67,6 +67,7 @@ static const struct file_operations befs_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= befs_readdir,
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static const struct inode_operations befs_dir_inode_operations = {
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
index 1e41aad..d78015e 100644
--- a/fs/bfs/dir.c
+++ b/fs/bfs/dir.c
@@ -80,6 +80,7 @@ const struct file_operations bfs_dir_operations = {
 	.readdir	= bfs_readdir,
 	.fsync		= simple_fsync,
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 extern void dump_imap(const char *, struct super_block *);
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index 88b9a3f..7f61ed6 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -29,6 +29,7 @@ const struct file_operations bfs_file_operations = {
 	.aio_write	= generic_file_aio_write,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int bfs_move_block(unsigned long from, unsigned long to,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6ed434a..281a2b8 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1164,4 +1164,5 @@ const struct file_operations btrfs_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= btrfs_ioctl,
 #endif
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 4deb280..606c31d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5971,6 +5971,7 @@ static const struct file_operations btrfs_dir_file_operations = {
 #endif
 	.release        = btrfs_release_file,
 	.fsync		= btrfs_sync_file,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static struct extent_io_ops btrfs_extent_io_ops = {
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 8a1ea6e..7a28ac5 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -718,6 +718,7 @@ static const struct file_operations btrfs_ctl_fops = {
 	.unlocked_ioctl	 = btrfs_control_ioctl,
 	.compat_ioctl = btrfs_control_ioctl,
 	.owner	 = THIS_MODULE,
+	.checkpoint = generic_file_checkpoint,
 };
 
 static struct miscdevice btrfs_misc = {
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index dd3634e..0927503 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -532,6 +532,7 @@ static const struct file_operations cramfs_directory_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= cramfs_readdir,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static const struct inode_operations cramfs_dir_inode_operations = {
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 678172b..a8973ef 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -305,6 +305,7 @@ const struct file_operations ecryptfs_dir_fops = {
 	.fsync = ecryptfs_fsync,
 	.fasync = ecryptfs_fasync,
 	.splice_read = generic_file_splice_read,
+	.checkpoint = generic_file_checkpoint,
 };
 
 const struct file_operations ecryptfs_main_fops = {
@@ -322,6 +323,7 @@ const struct file_operations ecryptfs_main_fops = {
 	.fsync = ecryptfs_fsync,
 	.fasync = ecryptfs_fasync,
 	.splice_read = generic_file_splice_read,
+	.checkpoint = generic_file_checkpoint,
 };
 
 static int
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 4ec8f61..9fd9b39 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -481,6 +481,7 @@ static const struct file_operations ecryptfs_miscdev_fops = {
 	.read    = ecryptfs_miscdev_read,
 	.write   = ecryptfs_miscdev_write,
 	.release = ecryptfs_miscdev_release,
+	.checkpoint = generic_file_checkpoint,
 };
 
 static struct miscdevice ecryptfs_miscdev = {
diff --git a/fs/efs/dir.c b/fs/efs/dir.c
index 7ee6f7e..da344b8 100644
--- a/fs/efs/dir.c
+++ b/fs/efs/dir.c
@@ -13,6 +13,7 @@ const struct file_operations efs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= efs_readdir,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations efs_dir_inode_operations = {
diff --git a/fs/exofs/dir.c b/fs/exofs/dir.c
index 4cfab1c..f6693d3 100644
--- a/fs/exofs/dir.c
+++ b/fs/exofs/dir.c
@@ -667,4 +667,5 @@ const struct file_operations exofs_dir_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= exofs_readdir,
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/exofs/file.c b/fs/exofs/file.c
index 839b9dc..257e9da 100644
--- a/fs/exofs/file.c
+++ b/fs/exofs/file.c
@@ -73,6 +73,7 @@ static int exofs_flush(struct file *file, fl_owner_t id)
 
 const struct file_operations exofs_file_operations = {
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 530b4ca..e3fa353 100644
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -841,6 +841,7 @@ const struct file_operations fat_dir_operations = {
 	.compat_ioctl	= fat_compat_dir_ioctl,
 #endif
 	.fsync		= fat_file_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int fat_get_short_entry(struct inode *dir, loff_t *pos,
diff --git a/fs/fat/file.c b/fs/fat/file.c
index e8c159d..e5aecc6 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -162,6 +162,7 @@ const struct file_operations fat_file_operations = {
 	.ioctl		= fat_generic_ioctl,
 	.fsync		= fat_file_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int fat_cont_expand(struct inode *inode, loff_t size)
diff --git a/fs/freevxfs/vxfs_lookup.c b/fs/freevxfs/vxfs_lookup.c
index aee049c..3a09132 100644
--- a/fs/freevxfs/vxfs_lookup.c
+++ b/fs/freevxfs/vxfs_lookup.c
@@ -58,6 +58,7 @@ const struct inode_operations vxfs_dir_inode_ops = {
 
 const struct file_operations vxfs_dir_operations = {
 	.readdir =		vxfs_readdir,
+	.checkpoint =		generic_file_checkpoint,
 };
 
  
diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
index 2b3b861..0eef6c2 100644
--- a/fs/hfs/dir.c
+++ b/fs/hfs/dir.c
@@ -329,6 +329,7 @@ const struct file_operations hfs_dir_operations = {
 	.readdir	= hfs_readdir,
 	.llseek		= generic_file_llseek,
 	.release	= hfs_dir_release,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations hfs_dir_inode_operations = {
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index a1cbff2..bf8950f 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -607,6 +607,7 @@ static const struct file_operations hfs_file_operations = {
 	.fsync		= file_fsync,
 	.open		= hfs_file_open,
 	.release	= hfs_file_release,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static const struct inode_operations hfs_file_inode_operations = {
diff --git a/fs/hfsplus/dir.c b/fs/hfsplus/dir.c
index 5f40236..41fbf2d 100644
--- a/fs/hfsplus/dir.c
+++ b/fs/hfsplus/dir.c
@@ -497,4 +497,5 @@ const struct file_operations hfsplus_dir_operations = {
 	.ioctl          = hfsplus_ioctl,
 	.llseek		= generic_file_llseek,
 	.release	= hfsplus_dir_release,
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 1bcf597..19abd7e 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -286,6 +286,7 @@ static const struct file_operations hfsplus_file_operations = {
 	.open		= hfsplus_file_open,
 	.release	= hfsplus_file_release,
 	.ioctl          = hfsplus_ioctl,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 struct inode *hfsplus_new_inode(struct super_block *sb, int mode)
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 032604e..67e2356 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -417,6 +417,7 @@ int hostfs_fsync(struct file *file, struct dentry *dentry, int datasync)
 
 static const struct file_operations hostfs_file_fops = {
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 	.read		= do_sync_read,
 	.splice_read	= generic_file_splice_read,
 	.aio_read	= generic_file_aio_read,
@@ -430,6 +431,7 @@ static const struct file_operations hostfs_file_fops = {
 
 static const struct file_operations hostfs_dir_fops = {
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 	.readdir	= hostfs_readdir,
 	.read		= generic_read_dir,
 };
diff --git a/fs/hpfs/dir.c b/fs/hpfs/dir.c
index 8865c94..dcde10f 100644
--- a/fs/hpfs/dir.c
+++ b/fs/hpfs/dir.c
@@ -322,4 +322,5 @@ const struct file_operations hpfs_dir_ops =
 	.readdir	= hpfs_readdir,
 	.release	= hpfs_dir_release,
 	.fsync		= hpfs_file_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index 3efabff..f1211f0 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -139,6 +139,7 @@ const struct file_operations hpfs_file_ops =
 	.release	= hpfs_file_release,
 	.fsync		= hpfs_file_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations hpfs_file_iops =
diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c
index 7239efc..e3c3bd3 100644
--- a/fs/hppfs/hppfs.c
+++ b/fs/hppfs/hppfs.c
@@ -546,6 +546,7 @@ static const struct file_operations hppfs_file_fops = {
 	.read		= hppfs_read,
 	.write		= hppfs_write,
 	.open		= hppfs_open,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 struct hppfs_dirent {
@@ -597,6 +598,7 @@ static const struct file_operations hppfs_dir_fops = {
 	.readdir	= hppfs_readdir,
 	.open		= hppfs_dir_open,
 	.fsync		= hppfs_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int hppfs_statfs(struct dentry *dentry, struct kstatfs *sf)
diff --git a/fs/isofs/dir.c b/fs/isofs/dir.c
index 8ba5441..848059d 100644
--- a/fs/isofs/dir.c
+++ b/fs/isofs/dir.c
@@ -273,6 +273,7 @@ const struct file_operations isofs_dir_operations =
 {
 	.read = generic_read_dir,
 	.readdir = isofs_readdir,
+	.checkpoint = generic_file_checkpoint,
 };
 
 /*
diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c
index 7aa4417..c7c4dcb 100644
--- a/fs/jffs2/dir.c
+++ b/fs/jffs2/dir.c
@@ -41,6 +41,7 @@ const struct file_operations jffs2_dir_operations =
 	.unlocked_ioctl=jffs2_ioctl,
 	.fsync =	jffs2_fsync,
 	.llseek =	generic_file_llseek,
+	.checkpoint =	generic_file_checkpoint,
 };
 
 
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index b7b74e2..f01038d 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -50,6 +50,7 @@ const struct file_operations jffs2_file_operations =
 	.mmap =		generic_file_readonly_mmap,
 	.fsync =	jffs2_fsync,
 	.splice_read =	generic_file_splice_read,
+	.checkpoint =	generic_file_checkpoint,
 };
 
 /* jffs2_file_inode_operations */
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index 2b70fa7..3bd7114 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -116,4 +116,5 @@ const struct file_operations jfs_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= jfs_compat_ioctl,
 #endif
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index c79a427..585a7d2 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1556,6 +1556,7 @@ const struct file_operations jfs_dir_operations = {
 	.compat_ioctl	= jfs_compat_ioctl,
 #endif
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static int jfs_ci_hash(struct dentry *dir, struct qstr *this)
diff --git a/fs/minix/dir.c b/fs/minix/dir.c
index 6198731..74b6fb4 100644
--- a/fs/minix/dir.c
+++ b/fs/minix/dir.c
@@ -23,6 +23,7 @@ const struct file_operations minix_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= minix_readdir,
 	.fsync		= simple_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static inline void dir_put_page(struct page *page)
diff --git a/fs/minix/file.c b/fs/minix/file.c
index 3eec3e6..2048d09 100644
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -21,6 +21,7 @@ const struct file_operations minix_file_operations = {
 	.mmap		= generic_file_mmap,
 	.fsync		= simple_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations minix_file_inode_operations = {
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 3c7f03b..7d9d22a 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -63,6 +63,7 @@ const struct file_operations nfs_dir_operations = {
 	.open		= nfs_opendir,
 	.release	= nfs_release,
 	.fsync		= nfs_fsync_dir,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations nfs_dir_inode_operations = {
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 63f2071..4437ef9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -78,6 +78,7 @@ const struct file_operations nfs_file_operations = {
 	.splice_write	= nfs_file_splice_write,
 	.check_flags	= nfs_check_flags,
 	.setlease	= nfs_setlease,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations nfs_file_inode_operations = {
@@ -577,6 +578,9 @@ out_unlock:
 static const struct vm_operations_struct nfs_file_vm_ops = {
 	.fault = filemap_fault,
 	.page_mkwrite = nfs_vm_page_mkwrite,
+#ifdef CONFIG_CHECKPOINT
+	.checkpoint = filemap_checkpoint,
+#endif
 };
 
 static int nfs_need_sync_write(struct file *filp, struct inode *inode)
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index 76d803e..18b2171 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -702,5 +702,5 @@ const struct file_operations nilfs_dir_operations = {
 	.compat_ioctl	= nilfs_ioctl,
 #endif	/* CONFIG_COMPAT */
 	.fsync		= nilfs_sync_file,
-
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 30292df..4d585b5 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -136,6 +136,7 @@ static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
  */
 const struct file_operations nilfs_file_operations = {
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
diff --git a/fs/ntfs/dir.c b/fs/ntfs/dir.c
index 5a9e344..4fe3759 100644
--- a/fs/ntfs/dir.c
+++ b/fs/ntfs/dir.c
@@ -1572,4 +1572,5 @@ const struct file_operations ntfs_dir_ops = {
 	/*.ioctl	= ,*/			/* Perform function on the
 						   mounted filesystem. */
 	.open		= ntfs_dir_open,	/* Open directory. */
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index 43179dd..32a43f5 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -2224,7 +2224,7 @@ const struct file_operations ntfs_file_ops = {
 						    mounted filesystem. */
 	.mmap		= generic_file_mmap,	 /* Mmap file. */
 	.open		= ntfs_file_open,	 /* Open file. */
-	.splice_read	= generic_file_splice_read /* Zero-copy data send with
+	.splice_read	= generic_file_splice_read, /* Zero-copy data send with
 						    the data source being on
 						    the ntfs partition.  We do
 						    not need to care about the
@@ -2234,6 +2234,7 @@ const struct file_operations ntfs_file_ops = {
 						    on the ntfs partition.  We
 						    do not need to care about
 						    the data source. */
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations ntfs_file_inode_ops = {
diff --git a/fs/omfs/dir.c b/fs/omfs/dir.c
index b42d624..e924e33 100644
--- a/fs/omfs/dir.c
+++ b/fs/omfs/dir.c
@@ -502,4 +502,5 @@ const struct file_operations omfs_dir_operations = {
 	.read = generic_read_dir,
 	.readdir = omfs_readdir,
 	.llseek = generic_file_llseek,
+	.checkpoint = generic_file_checkpoint,
 };
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index 399487c..83e63ef 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -331,6 +331,7 @@ const struct file_operations omfs_file_operations = {
 	.mmap = generic_file_mmap,
 	.fsync = simple_fsync,
 	.splice_read = generic_file_splice_read,
+	.checkpoint = generic_file_checkpoint,
 };
 
 const struct inode_operations omfs_file_inops = {
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index ffcd04f..d1f0677 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -160,6 +160,7 @@ static const struct file_operations openpromfs_prop_ops = {
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
+	.checkpoint	= NULL,
 };
 
 static int openpromfs_readdir(struct file *, void *, filldir_t);
@@ -168,6 +169,7 @@ static const struct file_operations openprom_operations = {
 	.read		= generic_read_dir,
 	.readdir	= openpromfs_readdir,
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static struct dentry *openpromfs_lookup(struct inode *, struct dentry *, struct nameidata *);
diff --git a/fs/qnx4/dir.c b/fs/qnx4/dir.c
index 6f30c3d..fa14c55 100644
--- a/fs/qnx4/dir.c
+++ b/fs/qnx4/dir.c
@@ -80,6 +80,7 @@ const struct file_operations qnx4_dir_operations =
 	.read		= generic_read_dir,
 	.readdir	= qnx4_readdir,
 	.fsync		= simple_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations qnx4_dir_inode_operations =
diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c
index 78f613c..4430239 100644
--- a/fs/ramfs/file-mmu.c
+++ b/fs/ramfs/file-mmu.c
@@ -47,6 +47,7 @@ const struct file_operations ramfs_file_operations = {
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations ramfs_file_inode_operations = {
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 1739a4a..9cd6208 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -45,6 +45,7 @@ const struct file_operations ramfs_file_operations = {
 	.splice_read		= generic_file_splice_read,
 	.splice_write		= generic_file_splice_write,
 	.llseek			= generic_file_llseek,
+	.checkpoint		= generic_file_checkpoint,
 };
 
 const struct inode_operations ramfs_file_inode_operations = {
diff --git a/fs/read_write.c b/fs/read_write.c
index e258301..65371e1 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -27,6 +27,7 @@ const struct file_operations generic_ro_fops = {
 	.aio_read	= generic_file_aio_read,
 	.mmap		= generic_file_readonly_mmap,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 EXPORT_SYMBOL(generic_ro_fops);
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c
index c094f58..8681419 100644
--- a/fs/reiserfs/dir.c
+++ b/fs/reiserfs/dir.c
@@ -24,6 +24,7 @@ const struct file_operations reiserfs_dir_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = reiserfs_compat_ioctl,
 #endif
+	.checkpoint = generic_file_checkpoint,
 };
 
 static int reiserfs_dir_fsync(struct file *filp, struct dentry *dentry,
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index da2dba0..b6008f3 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -297,6 +297,7 @@ const struct file_operations reiserfs_file_operations = {
 	.splice_read = generic_file_splice_read,
 	.splice_write = generic_file_splice_write,
 	.llseek = generic_file_llseek,
+	.checkpoint = generic_file_checkpoint,
 };
 
 const struct inode_operations reiserfs_file_inode_operations = {
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index f0511e8..03c24d9 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -72,4 +72,5 @@ const struct file_operations romfs_ro_fops = {
 	.splice_read		= generic_file_splice_read,
 	.mmap			= romfs_mmap,
 	.get_unmapped_area	= romfs_get_unmapped_area,
+	.checkpoint		= generic_file_checkpoint,
 };
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 42d2135..476ea8e 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -282,6 +282,7 @@ error:
 static const struct file_operations romfs_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= romfs_readdir,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static const struct inode_operations romfs_dir_inode_operations = {
diff --git a/fs/squashfs/dir.c b/fs/squashfs/dir.c
index 566b0ea..b0c5336 100644
--- a/fs/squashfs/dir.c
+++ b/fs/squashfs/dir.c
@@ -231,5 +231,6 @@ failed_read:
 
 const struct file_operations squashfs_dir_ops = {
 	.read = generic_read_dir,
-	.readdir = squashfs_readdir
+	.readdir = squashfs_readdir,
+	.checkpoint = generic_file_checkpoint,
 };
diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 4e50286..53acd29 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -25,6 +25,7 @@ const struct file_operations sysv_dir_operations = {
 	.read		= generic_read_dir,
 	.readdir	= sysv_readdir,
 	.fsync		= simple_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static inline void dir_put_page(struct page *page)
diff --git a/fs/sysv/file.c b/fs/sysv/file.c
index 96340c0..aee556d 100644
--- a/fs/sysv/file.c
+++ b/fs/sysv/file.c
@@ -28,6 +28,7 @@ const struct file_operations sysv_file_operations = {
 	.mmap		= generic_file_mmap,
 	.fsync		= simple_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct inode_operations sysv_file_inode_operations = {
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index 9049232..e4f23c6 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -2623,6 +2623,7 @@ static ssize_t write_debugfs_file(struct file *file, const char __user *buf,
 static const struct file_operations dfs_fops = {
 	.open = open_debugfs_file,
 	.write = write_debugfs_file,
+	.checkpoint = generic_file_checkpoint,
 	.owner = THIS_MODULE,
 };
 
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 552fb01..89ab2aa 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -1228,4 +1228,5 @@ const struct file_operations ubifs_dir_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = ubifs_compat_ioctl,
 #endif
+	.checkpoint     = generic_file_checkpoint,
 };
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 16a6444..254a4d9 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1582,4 +1582,5 @@ const struct file_operations ubifs_file_operations = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = ubifs_compat_ioctl,
 #endif
+	.checkpoint     = generic_file_checkpoint,
 };
diff --git a/fs/udf/dir.c b/fs/udf/dir.c
index 61d9a76..6586dbe 100644
--- a/fs/udf/dir.c
+++ b/fs/udf/dir.c
@@ -211,4 +211,5 @@ const struct file_operations udf_dir_operations = {
 	.readdir		= udf_readdir,
 	.ioctl			= udf_ioctl,
 	.fsync			= simple_fsync,
+	.checkpoint		= generic_file_checkpoint,
 };
diff --git a/fs/udf/file.c b/fs/udf/file.c
index f311d50..e671552 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -215,6 +215,7 @@ const struct file_operations udf_file_operations = {
 	.fsync			= simple_fsync,
 	.splice_read		= generic_file_splice_read,
 	.llseek			= generic_file_llseek,
+	.checkpoint		= generic_file_checkpoint,
 };
 
 const struct inode_operations udf_file_inode_operations = {
diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c
index 22af68f..29c9396 100644
--- a/fs/ufs/dir.c
+++ b/fs/ufs/dir.c
@@ -668,4 +668,5 @@ const struct file_operations ufs_dir_operations = {
 	.readdir	= ufs_readdir,
 	.fsync		= simple_fsync,
 	.llseek		= generic_file_llseek,
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/ufs/file.c b/fs/ufs/file.c
index 73655c6..15c8616 100644
--- a/fs/ufs/file.c
+++ b/fs/ufs/file.c
@@ -43,4 +43,5 @@ const struct file_operations ufs_file_operations = {
 	.open           = generic_file_open,
 	.fsync		= simple_fsync,
 	.splice_read	= generic_file_splice_read,
+	.checkpoint	= generic_file_checkpoint,
 };
diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index e4caeb2..926f377 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -259,6 +259,7 @@ const struct file_operations xfs_file_operations = {
 #ifdef HAVE_FOP_OPEN_EXEC
 	.open_exec	= xfs_file_open_exec,
 #endif
+	.checkpoint	= generic_file_checkpoint,
 };
 
 const struct file_operations xfs_dir_file_operations = {
@@ -271,6 +272,7 @@ const struct file_operations xfs_dir_file_operations = {
 	.compat_ioctl	= xfs_file_compat_ioctl,
 #endif
 	.fsync		= xfs_file_fsync,
+	.checkpoint	= generic_file_checkpoint,
 };
 
 static const struct vm_operations_struct xfs_file_vm_ops = {
-- 
1.6.3.3

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Re: [C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems

[Andreas Dilger]

On 2010-03-17, at 10:08, Oren Laadan wrote:
> These patches extend the use of the generic file checkpoint  
> operation to
> non-extX filesystems which have lseek operations that ensure we can  
> save
> and restore the files for later use. Note that this does not include
> things like FUSE, network filesystems, or pseudo-filesystem kernel
> interfaces.

I didn't see any other patches posted to linux-fsdevel regarding what  
this code is, or what it is supposed to be doing.  Could you please  
repost the patches related to generic_file_checkpoint(), and the  
overview email that explains what you mean by "checkpoint".  I'm  
assuming this is related to HPC/process restart/migration, but better  
to not guess.

> @@ -718,6 +718,7 @@ static const struct file_operations  
> btrfs_ctl_fops = {
> 	.unlocked_ioctl	 = btrfs_control_ioctl,
> 	.compat_ioctl = btrfs_control_ioctl,
> 	.owner	 = THIS_MODULE,
> +	.checkpoint = generic_file_checkpoint,
> };
>
> const struct file_operations exofs_file_operations = {
> 	.llseek		= generic_file_llseek,
> +	.checkpoint	= generic_file_checkpoint,
> 	.read		= do_sync_read,
> 	.write		= do_sync_write,
> 	.aio_read	= generic_file_aio_read,
>
> static const struct file_operations hostfs_file_fops = {
> 	.llseek		= generic_file_llseek,
> +	.checkpoint	= generic_file_checkpoint,
> 	.read		= do_sync_read,
> 	.splice_read	= generic_file_splice_read,
> 	.aio_read	= generic_file_aio_read,
> @@ -430,6 +431,7 @@ static const struct file_operations  
> hostfs_file_fops = {
>
> static const struct file_operations hostfs_dir_fops = {
> 	.llseek		= generic_file_llseek,
> +	.checkpoint	= generic_file_checkpoint,
> 	.readdir	= hostfs_readdir,
> 	.read		= generic_read_dir,
> };
>
> const struct file_operations nilfs_file_operations = {
> 	.llseek		= generic_file_llseek,
> +	.checkpoint	= generic_file_checkpoint,
> 	.read		= do_sync_read,
> 	.write		= do_sync_write,
> 	.aio_read	= generic_file_aio_read,


Minor nit - it would be good to add this method in the same place in  
all of the *_file_operation structures for consistency.  Ideally these  
would already be in the order that they are declared in the structure,  
but at least new ones should be added consistently.

> static const struct vm_operations_struct nfs_file_vm_ops = {
> 	.fault = filemap_fault,
> 	.page_mkwrite = nfs_vm_page_mkwrite,
> +#ifdef CONFIG_CHECKPOINT
> +	.checkpoint = filemap_checkpoint,
> +#endif
> };

Why is this one conditional, but the others are not?


Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

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Re: [C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems

[Matt Helsley]

On Wed, Mar 17, 2010 at 03:09:00PM -0600, Andreas Dilger wrote:
> On 2010-03-17, at 10:08, Oren Laadan wrote:
> >These patches extend the use of the generic file checkpoint
> >operation to
> >non-extX filesystems which have lseek operations that ensure we
> >can save
> >and restore the files for later use. Note that this does not include
> >things like FUSE, network filesystems, or pseudo-filesystem kernel
> >interfaces.
> 
> I didn't see any other patches posted to linux-fsdevel regarding
> what this code is, or what it is supposed to be doing.  Could you
> please repost the patches related to generic_file_checkpoint(), and

I'm not sure why those weren't sent to linux-fsdevel. It mainly saves
the critical pieces of kernel information from the struct file needed
to restart the open file descriptors. It does not save the file
(system) contents in the checkpoint image. That's left for proper
filesystem freezing, snapshotting, or rsync (for example) depending on
the tools and/or filesystems userspace has chosen.

> the overview email that explains what you mean by "checkpoint".  I'm
> assuming this is related to HPC/process restart/migration, but
> better to not guess.

Your assumption is correct -- this is related to HPC/process
restart/migration. That said, we'd like to make it as useful as
possible for other folks as well.

> 
> >@@ -718,6 +718,7 @@ static const struct file_operations
> >btrfs_ctl_fops = {
> >	.unlocked_ioctl	 = btrfs_control_ioctl,
> >	.compat_ioctl = btrfs_control_ioctl,
> >	.owner	 = THIS_MODULE,
> >+	.checkpoint = generic_file_checkpoint,
> >};
> >
> >const struct file_operations exofs_file_operations = {
> >	.llseek		= generic_file_llseek,
> >+	.checkpoint	= generic_file_checkpoint,
> >	.read		= do_sync_read,
> >	.write		= do_sync_write,
> >	.aio_read	= generic_file_aio_read,
> >
> >static const struct file_operations hostfs_file_fops = {
> >	.llseek		= generic_file_llseek,
> >+	.checkpoint	= generic_file_checkpoint,
> >	.read		= do_sync_read,
> >	.splice_read	= generic_file_splice_read,
> >	.aio_read	= generic_file_aio_read,
> >@@ -430,6 +431,7 @@ static const struct file_operations
> >hostfs_file_fops = {
> >
> >static const struct file_operations hostfs_dir_fops = {
> >	.llseek		= generic_file_llseek,
> >+	.checkpoint	= generic_file_checkpoint,
> >	.readdir	= hostfs_readdir,
> >	.read		= generic_read_dir,
> >};
> >
> >const struct file_operations nilfs_file_operations = {
> >	.llseek		= generic_file_llseek,
> >+	.checkpoint	= generic_file_checkpoint,
> >	.read		= do_sync_read,
> >	.write		= do_sync_write,
> >	.aio_read	= generic_file_aio_read,
> 
> 
> Minor nit - it would be good to add this method in the same place in
> all of the *_file_operation structures for consistency.  Ideally
> these would already be in the order that they are declared in the
> structure, but at least new ones should be added consistently.

I chose to put them right after llseek because that's a critical
operation that determines whether generic_file_checkpoint is suitable
or whether a custom operation is needed. Since the placement here
has nothing to do with the order in memory it's mainly a convention
I thought up to support review of copy-pasted file operations with
new .checkpoint ops.

I'll post a patch to move these down to correspond to definition-order
unless you agree that my reasoning above justifies keeping them
where they are.

> 
> >static const struct vm_operations_struct nfs_file_vm_ops = {
> >	.fault = filemap_fault,
> >	.page_mkwrite = nfs_vm_page_mkwrite,
> >+#ifdef CONFIG_CHECKPOINT
> >+	.checkpoint = filemap_checkpoint,
> >+#endif
> >};
> 
> Why is this one conditional, but the others are not?

filemap_checkpoint is defined in mm/filemap.c and the !CONFIG_CHECKPOINT
section has:

#define filemap_checkpoint NULL

Of course since it's not in a header file that define is useless
elsewhere hence the conditional here. We should move that to a
proper header. Good catch, thanks!

Cheers,
	-Matt Helsley

Re: [C/R v20][PATCH 46/96] c/r: add checkpoint operation for opened files of generic filesystems

[Matt Helsley]

On Wed, Mar 17, 2010 at 03:09:00PM -0600, Andreas Dilger wrote:

<snip> (already responded to the first part)

> >static const struct vm_operations_struct nfs_file_vm_ops = {
> >	.fault = filemap_fault,
> >	.page_mkwrite = nfs_vm_page_mkwrite,
> >+#ifdef CONFIG_CHECKPOINT
> >+	.checkpoint = filemap_checkpoint,
> >+#endif
> >};
> 
> Why is this one conditional, but the others are not?

Something like this perhaps (untested, but it should work).

    Move empty filemap_checkpoint definition
    
    This makes the operation usable in the nfs vm operation structure
    and avoids the extra #ifdef.
    
    Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
    Cc: Andreas Dilger <adilger@sun.com>

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 4437ef9..c6f9090 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -578,9 +578,7 @@ out_unlock:
 static const struct vm_operations_struct nfs_file_vm_ops = {
 	.fault = filemap_fault,
 	.page_mkwrite = nfs_vm_page_mkwrite,
-#ifdef CONFIG_CHECKPOINT
 	.checkpoint = filemap_checkpoint,
-#endif
 };
 
 static int nfs_need_sync_write(struct file *filp, struct inode *inode)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 210d8e3..e9d9605 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1206,6 +1206,8 @@ extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
 #ifdef CONFIG_CHECKPOINT
 /* generic vm_area_ops exported for mapped files checkpoint */
 extern int filemap_checkpoint(struct ckpt_ctx *, struct vm_area_struct *);
+#else /* !CONFIG_CHECKPOINT */
+#define filemap_checkpoint NULL
 #endif
 
 /* mm/page-writeback.c */
diff --git a/mm/filemap.c b/mm/filemap.c
index 4ea28e6..bc98a15 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1678,8 +1678,6 @@ int filemap_restore(struct ckpt_ctx *ctx,
 	}
 	return ret;
 }
-#else /* !CONFIG_CHECKPOINT */
-#define filemap_checkpoint NULL
 #endif
 
 const struct vm_operations_struct generic_file_vm_ops = {

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[C/R v20][PATCH 00/96] Linux Checkpoint-Restart - v20

[Oren Laadan]

Hi,

Following Andreas Dilger's reply (http://lkml.org/lkml/2010/3/17/410)
I'm (re)posting the subset of checkpoint-restart patch-set that is
related to linux-fsdevel. (I'm unsure why those weren't sent before).
Altogether there are 17 patches here (out of the 96 total).

For the original post/thread see: http://lkml.org/lkml/2010/3/17/232.

As Matt Helsley put briefly, checkpoint-restart mainly saves the
critical pieces of kernel information from the struct file needed to
restart the open file descriptors. It does not save the file (system)
contents in the checkpoint image. That's left for proper filesystem
freezing, snapshotting, or rsync (for example) depending on the tools
and/or filesystems userspace has chosen.

Oren.

---

Here is the introduction to the original post:

---

Following up on the thread on the checkpoint-restart patch set
(http://lkml.org/lkml/2010/3/1/422), the following series is the
latest checkpoint/restart, based on 2.6.33.

The first 20 patches are cleanups and prepartion for c/r; they
are followed by the actual c/r code.

Please apply to -mm, and let us know if there is any way we can
help.

---

Linux Checkpoint-Restart:
 web, wiki:	http://www.linux-cr.org
 bug track:	https://www.linux-cr.org/redmine

The repositories for the project are in:
 kernel:	http://www.linux-cr.org/git/?p=linux-cr.git;a=summary
 user tools:	http://www.linux-cr.org/git/?p=user-cr.git;a=summary
 tests suite:	http://www.linux-cr.org/git/?p=tests-cr.git;a=summary

---

CHANGELOG:

v20 [2010-Mar-16]
 BUG FIXES (only)
  - [Serge Hallyn] Fix unlabeled restore case
  - [Serge Hallyn] Always restore msg_msg label
  - [Serge Hallyn] Selinux prevents msgrcv on restore message queues?
  - [Serge Hallyn] save_access_regs for self-checkpoint
  - [Serge Hallyn] send uses_interp=1 to arch_setup_additional_pages
  - Fix "scheduling in atomic" while restoring ipc (sem, shm, msg)
  - Cleanup: no need to restore perm->{id,key,seq}
  - Fix sysvipc=n compile
  - Make uts_ns=n compile
  - Only use arch_setup_additional_pages() if supported by arch
  - Export key symbols to enable c/r from kernel modules
  - Avoid crash if incoming object doesn't have .restore
  - Replace error_sem with an event completion
  - [Serge Hallyn] Change sysctl and default for unprivileged use
  - [Nathan Lynch] Use syscall_get_error
  - Add entry for checkpoint/restart in MAINTAINERS 

[2010-Feb-19] v19
 NEW FEATURES
  - Support for x86-64 architecture
  - Support for c/r of LSM (smack, selinux)
  - Support for c/r of task fs_root and pwd
  - Support for c/r of epoll
  - Support for c/r of eventfd
  - Enable C/R while executing over NFS
  - Preliminary c/r of mounts namespace
  - Add @logfd argument to sys_{checkpoint,restart} prototypes
  - Define new api for error and debug logging
  - Restart to handle checkpoint images lacking {uts,ipc}-ns
  - Refuse to checkpoint if monitoring directories with dnotify
  - Refuse to checkpoint if file locks and leases are held
  - Refuse to checkpoint files with f_owner 
 OTHER CHANGES
  - Rebase to kernel 2.6.33-rc8
  - Settled version of new sys_eclone()
  - [Serge Hallyn] Fix potential use-before-set return (vdso)
  - Update documentation and examples for new syscalls API (doc)
  - [Liu Alexander] Fix typos (doc)
  - [Serge Hallyn] Update checkpoint image format (doc)
  - [Serge Hallyn] Use ckpt_err() to for bad header values
  - sys_{checkpoint,restart} to use ptregs prototype
  - Set ctx->errno in do_ckpt_msg() if needed
  - Fix up headers so we can munge them for use by userspace
  - Multiple fixes to _ckpt_write_err() and friends
  - [Matt Helsley] Add cpp definitions for enums
  - [Serge Hallyn] Add global section container to image format
  - [Matt Helsley] Fix total byte read/write count for large images
  - ckpt_read_buf_type() to accept max payload (excludes ckpt_hdr)
  - [Serge Hallyn] Use ckpt_err() for arch incompatbilities
  - Introduce walk_task_subtree() to iterate through descendants
  - Call restore_notify_error for restart (not checkpoint !)
  - Make kread/kwrite() abort if CKPT_CTX_ERROR is set
  - [Serge Hallyn] Move init_completion(&ctx->complete) to ctx_alloc
  - Simplify logic of tracking restarting tasks (->ctx)
  - Coordinator kills descendants on failure for proper cleanup
  - Prepare descendants needs PTRACE_MODE_ATTACH permissions
  - Threads wait for entire thread group before restoring
  - Add debug process-tree status during restart
  - Fix handling of bogus pid arg to sys_restart
  - In reparent_thread() test for PF_RESTARTING on parent
  - Keep __u32s in even groups for 32-64 bit compatibility
  - Define ckpt_obj_try_fetch
  - Disallow zero or negative objref during restart
  - Check for valid destructor before calling it (deferqueue)
  - Fix false negative of test for unlinked files at checkpoint
  - [Serge Hallyn] Rename fs_mnt to root_fs_path
  - Restore thread/cpu state early
  - Ensure null-termination of file names read from image
  - Fix compile warning in restore_open_fname()
  - Introduce FOLL_DIRTY to follow_page() for "dirty" pages
  - [Serge Hallyn] Checkpoint saved_auxv as u64s
  - Export filemap_checkpoint()
  - [Serge Hallyn] Disallow checkpoint of tasks with aio requests
  - Fix compilation failure when !CONFIG_CHEKCPOINT (regression)
  - Expose page write functions
  - Do not hold mmap_sem while checkpointing vma's
  - Do not hold mmap_sem when reading memory pages on restart
  -  Move consider_private_page() to mm/memory.c:__get_dirty_page()
  - [Serge Hallyn] move destroy_mm into mmap.c and remove size check
  - [Serge Hallyn] fill vdso (syscall32_setup_pages) for TIF_IA32/x86_64
  - [Serge Hallyn] Fix return value of read_pages_contents()
  - [Serge Hallyn] Change m_type to long, not int (ipc)
  - Don't free sma if it's an error on restore
  - Use task->saves_sigmask and drop task->checkpoint_data
  - [Serge Hallyn] Handle saved_sigmask at checkpoint
  - Defer restore of blocked signals mask during restart
  - Self-restart to tolerate missing PGIDs
  - [Serge Hallyn] skb->tail can be offset
  - Export and leverage sock_alloc_file()
  - [Nathan Lynch] Fix net/checkpoint.c for 64-bit
  - [Dan Smith] Unify skb read/write functions and handle fragmented buffers
  - [Dan Smith] Update buffer restore code to match the new format
  - [Dan Smith] Fix compile issue with CONFIG_CHECKPOINT=n
  - [Dan Smith] Remove an unnecessary check on socket restart
  - [Dan Smith] Pass the stored sock->protocol into sock_create() on restore
  - Relax tcp.window_clamp value in INET restore
  - Restore gso_type fields on sockets and buffers for proper operation
  - Fix broken compilation for no-c/r architectures
  - Return -EBUSY (not BUG_ON) if fd is gone on restart
  - Fix the chunk size instead of auto-tune (epoll) 
 ARCH: x86 (32,64)
  - Use PTREGSCALL4 for sys_{checkpoint,restart}
  - Remove debug-reg support (need to redo with perf_events)
  - [Serge Hallyn] Support for ia32 (checkpoint, restart)
  - Split arch/x86/checkpoint.c to generic and 32bit specific parts
  - sys_{checkpoint,restore} to use ptregs
  - Allow X86_EFLAGS_RF on restart
  - [Serge Hallyn] Only allow 'restart' with same bit-ness as image.
  - Move checkpoint.c from arch/x86/mm->arch/x86/kernel 
 ARCH: s390 [Serge Hallyn]
  - Define s390x sys_restart wrapper
  - Fixes to restart-blocks logic and signal path
  - Fix checkpoint and restart compat wrappers
  - sys_{checkpoint,restore} to use ptregs
  - Use simpler test_task_thread to test current ti flags
  - Fix 31-bit s390 checkpoint/restart wrappers
  - Update sys_checkpoint (do_sys_checkpoint on all archs)
  - [Oren Laadan] Move checkpoint.c from arch/s390/mm->arch/s390/kernel 
 ARCH: powerpc [Nathan Lynch]
  - [Serge Hallyn] Add hook task_has_saved_sigmask()
  - Warn if full register state unavailable
  - Fix up checkpoint syscall, tidy restart
  - [Oren Laadan] Move checkpoint.c from arch/powerpc/{mm->kernel} 

[2009-Sep-22] v18
 NEW FEATURES
  - [Nathan Lynch] Re-introduce powerpc support
  - Save/restore pseudo-terminals
  - Save/restore (pty) controlling terminals
  - Save/restore restore PGIDs
  - [Dan Smith] Save/restore unix domain sockets
  - Save/restore FIFOs
  - Save/restore pending signals
  - Save/restore rlimits
  - Save/restore itimers
  - [Matt Helsley] Handle many non-pseudo file-systems
 OTHER CHANGES
  - Rename headerless struct ckpt_hdr_* to struct ckpt_*
  - [Nathan Lynch] discard const from struct cred * where appropriate
  - [Serge Hallyn][s390] Set return value for self-checkpoint 
  - Handle kmalloc failure in restore_sem_array()
  - [IPC] Collect files used by shm objects
  - [IPC] Use file (not inode) as shared object on checkpoint of shm
  - More ckpt_write_err()s to give information on checkpoint failure
  - Adjust format of pipe buffer to include the mandatory pre-header
  - [LEAKS] Mark the backing file as visited at chekcpoint
  - Tighten checks on supported vma to checkpoint or restart
  - [Serge Hallyn] Export filemap_checkpoint() (used for ext4)
  - Introduce ckpt_collect_file() that also uses file->collect method
  - Use ckpt_collect_file() instead of ckpt_obj_collect() for files
  - Fix leak-detection issue in collect_mm() (test for first-time obj)
  - Invoke set_close_on_exec() unconditionally on restart
  - [Dan Smith] Export fill_fname() as ckpt_fill_fname()
  - Interface to pass simple pointers as data with deferqueue
  - [Dan Smith] Fix ckpt_obj_lookup_add() leak detection logic
  - Replace EAGAIN with EBUSY where necessary
  - Introduce CKPT_OBJ_VISITED in leak detection
  - ckpt_obj_collect() returns objref for new objects, 0 otherwise
  - Rename ckpt_obj_checkpointed() to ckpt_obj_visited()
  - Introduce ckpt_obj_visit() to mark objects as visited
  - Set the CHECKPOINTED flag on objects before calling checkpoint
  - Introduce ckpt_obj_reserve()
  - Change ref_drop() to accept a @lastref argument (for cleanup)
  - Disallow multiple objects with same objref in restart
  - Allow _ckpt_read_obj_type() to read header only (w/o payload)
  - Fix leak of ckpt_ctx when restoring zombie tasks
  - Fix race of prepare_descendant() with an ongoing fork()
  - Track and report the first error if restart fails
  - Tighten logic to protect against bogus pids in input
  - [Matt Helsley] Improve debug output from ckpt_notify_error()
  - [Nathan Lynch] fix compilation errors with CONFIG_COMPAT=y
  - Detect error-headers in input data on restart, and abort.
  - Standard format for checkpoint error strings (and documentation)
  - [Dan Smith] Add an errno validation function
  - Add ckpt_read_payload(): read a variable-length object (no header)
  - Add ckpt_read_string(): same for strings (ensures null-terminated)
  - Add ckpt_read_consume(): consumes next object without processing
  - [John Dykstra] Fix no-dot-config-targets pattern in linux/Makefile

[2009-Jul-21] v17
  - Introduce syscall clone_with_pids() to restore original pids
  - Support threads and zombies
  - Save/restore task->files
  - Save/restore task->sighand
  - Save/restore futex
  - Save/restore credentials
  - Introduce PF_RESTARTING to skip notifications on task exit
  - restart(2) allow caller to ask to freeze tasks after restart
  - restart(2) isn't idempotent: return -EINTR if interrupted
  - Improve debugging output handling 
  - Make multi-process restart logic more robust and complete
  - Correctly select return value for restarting tasks on success
  - Tighten ptrace test for checkpoint to PTRACE_MODE_ATTACH
  - Use CHECKPOINTING state for frozen checkpointed tasks
  - Fix compilation without CONFIG_CHECKPOINT
  - Fix compilation with CONFIG_COMPAT
  - Fix headers includes and exports
  - Leak detection performed in two steps
  - Detect "inverse" leaks of objects (dis)appearing unexpectedly
  - Memory: save/restore mm->{flags,def_flags,saved_auxv}
  - Memory: only collect sub-objects of mm once (leak detection)
  - Files: validate f_mode after restore
  - Namespaces: leak detection for nsproxy sub-components
  - Namespaces: proper restart from namespace(s) without namespace(s)
  - Save global constants in header instead of per-object
  - IPC: replace sys_unshare() with create_ipc_ns()
  - IPC: restore objects in suitable namespace
  - IPC: correct behavior under !CONFIG_IPC_NS
  - UTS: save/restore all fields
  - UTS: replace sys_unshare() with create_uts_ns()
  - X86_32: sanitize cpu, debug, and segment registers on restart
  - cgroup_freezer: add CHECKPOINTING state to safeguard checkpoint
  - cgroup_freezer: add interface to freeze a cgroup (given a task)

[2009-May-27] v16
  - Privilege checks for IPC checkpoint
  - Fix error string generation during checkpoint
  - Use kzalloc for header allocation
  - Restart blocks are arch-independent
  - Redo pipe c/r using splice
  - Fixes to s390 arch
  - Remove powerpc arch (temporary)
  - Explicitly restore ->nsproxy
  - All objects in image are precedeed by 'struct ckpt_hdr'
  - Fix leaks detection (and leaks)
  - Reorder of patchset
  - Misc bugs and compilation fixes

[2009-Apr-12] v15
  - Minor fixes

[2009-Apr-28] v14
  - Tested against kernel v2.6.30-rc3 on x86_32.
  - Refactor files chekpoint to use f_ops (file operations)
  - Refactor mm/vma to use vma_ops
  - Explicitly handle VDSO vma (and require compat mode)
  - Added code to c/r restat-blocks (restart timeout related syscalls)
  - Added code to c/r namespaces: uts, ipc (with Dan Smith)
  - Added code to c/r sysvipc (shm, msg, sem)
  - Support for VM_CLONE shared memory
  - Added resource leak detection for whole-container checkpoint
  - Added sysctl gauge to allow unprivileged restart/checkpoint
  - Improve and simplify the code and logic of shared objects
  - Rework image format: shared objects appear prior to their use
  - Merge checkpoint and restart functionality into same files
  - Massive renaming of functions: prefix "ckpt_" for generics,
    "checkpoint_" for checkpoint, and "restore_" for restart.
  - Report checkpoint errors as a valid (string record) in the output
  - Merged PPC architecture (by Nathan Lunch),
  - Requires updates to userspace tools too.
  - Misc nits and bug fixes

[2009-Mar-31] v14-rc2
  - Change along Dave's suggestion to use f_ops->checkpoint() for files
  - Merge patch simplifying Kconfig, with CONFIG_CHECKPOINT_SUPPORT
  - Merge support for PPC arch (Nathan Lynch)
  - Misc cleanups and fixes in response to comments

[2009-Mar-20] v14-rc1:
  - The 'h.parent' field of 'struct cr_hdr' isn't used - discard
  - Check whether calls to cr_hbuf_get() succeed or fail.
  - Fixed of pipe c/r code
  - Prevent deadlock by refusing c/r when a pipe inode == ctx->file inode
  - Refuse non-self checkpoint if a task isn't frozen
  - Use unsigned fields in checkpoint headers unless otherwise required
  - Rename functions in files c/r to better reflect their role
  - Add support for anonymous shared memory
  - Merge support for s390 arch (Dan Smith, Serge Hallyn)
    
[2008-Dec-03] v13:
  - Cleanups of 'struct cr_ctx' - remove unused fields
  - Misc fixes for comments
  
[2008-Dec-17] v12:
  - Fix re-alloc/reset of pgarr chain to correctly reuse buffers
    (empty pgarr are saves in a separate pool chain)
  - Add a couple of missed calls to cr_hbuf_put()
  - cr_kwrite/cr_kread() again use vfs_read(), vfs_write() (safer)
  - Split cr_write/cr_read() to two parts: _cr_write/read() helper
  - Befriend with sparse: explicit conversion to 'void __user *'
  - Redrefine 'pr_fmt' ind replace cr_debug() with pr_debug()

[2008-Dec-05] v11:
  - Use contents of 'init->fs->root' instead of pointing to it
  - Ignore symlinks (there is no such thing as an open symlink)
  - cr_scan_fds() retries from scratch if it hits size limits
  - Add missing test for VM_MAYSHARE when dumping memory
  - Improve documentation about: behavior when tasks aren't fronen,
    life span of the object hash, references to objects in the hash
 
[2008-Nov-26] v10:
  - Grab vfs root of container init, rather than current process
  - Acquire dcache_lock around call to __d_path() in cr_fill_name()
  - Force end-of-string in cr_read_string() (fix possible DoS)
  - Introduce cr_write_buffer(), cr_read_buffer() and cr_read_buf_type()

[2008-Nov-10] v9:
  - Support multiple processes c/r
  - Extend checkpoint header with archtiecture dependent header 
  - Misc bug fixes (see individual changelogs)
  - Rebase to v2.6.28-rc3.

[2008-Oct-29] v8:
  - Support "external" checkpoint
  - Include Dave Hansen's 'deny-checkpoint' patch
  - Split docs in Documentation/checkpoint/..., and improve contents

[2008-Oct-17] v7:
  - Fix save/restore state of FPU
  - Fix argument given to kunmap_atomic() in memory dump/restore

[2008-Oct-07] v6:
  - Balance all calls to cr_hbuf_get() with matching cr_hbuf_put()
    (even though it's not really needed)
  - Add assumptions and what's-missing to documentation
  - Misc fixes and cleanups

[2008-Sep-11] v5:
  - Config is now 'def_bool n' by default
  - Improve memory dump/restore code (following Dave Hansen's comments)
  - Change dump format (and code) to allow chunks of <vaddrs, pages>
    instead of one long list of each
  - Fix use of follow_page() to avoid faulting in non-present pages
  - Memory restore now maps user pages explicitly to copy data into them,
    instead of reading directly to user space; got rid of mprotect_fixup()
  - Remove preempt_disable() when restoring debug registers
  - Rename headers files s/ckpt/checkpoint/
  - Fix misc bugs in files dump/restore
  - Fixes and cleanups on some error paths
  - Fix misc coding style

[2008-Sep-09] v4:
  - Various fixes and clean-ups
  - Fix calculation of hash table size
  - Fix header structure alignment
  - Use stand list_... for cr_pgarr

[2008-Aug-29] v3:
  - Various fixes and clean-ups
  - Use standard hlist_... for hash table
  - Better use of standard kmalloc/kfree

[2008-Aug-20] v2:
  - Added Dump and restore of open files (regular and directories)
  - Added basic handling of shared objects, and improve handling of
    'parent tag' concept
  - Added documentation
  - Improved ABI, 64bit padding for image data
  - Improved locking when saving/restoring memory
  - Added UTS information to header (release, version, machine)
  - Cleanup extraction of filename from a file pointer
  - Refactor to allow easier reviewing
  - Remove requirement for CAPS_SYS_ADMIN until we come up with a
    security policy (this means that file restore may fail)
  - Other cleanup and response to comments for v1

[2008-Jul-29] v1:
  - Initial version: support a single task with address space of only
    private anonymous or file-mapped VMAs; syscalls ignore pid/crid
    argument and act on current process.

Re: [C/R v20][PATCH 00/96] Linux Checkpoint-Restart - v20

[Serge E. Hallyn]

Quoting Oren Laadan (orenl@cs.columbia.edu):
> Hi Andrew,
> 
> Following up on the thread on the checkpoint-restart patch set
> (http://lkml.org/lkml/2010/3/1/422), the following series is the
> latest checkpoint/restart, based on 2.6.33.
> 
> The first 20 patches are cleanups and prepartion for c/r; they
> are followed by the actual c/r code.
> 
> Please apply to -mm, and let us know if there is any way we can
> help.

Hi Andrew,

Oren sent v20 of the checkpoint/restart patchset out two weeks ago.
We've addressed some feedback from linux-fsdevel and added network and
pid namespace support.  So we could resend again now.  However we also
have a bigger patchset in the works which is feature-neutral, but moves
all the code out of linux-2.6/checkpoint/ and next to the code it
affects.  I ancitipate #ifdef clashes though, so we'll
need to do quite a bit of various-config-and-arch testing of the new
code layout.  If you're at a good point to pull it, we can resend the
code as is now so as to get some wider testing exposure. Or, if you prefer,
we can wait until after the code move in case that would be seen as more
amenable to meaningful review.

We don't want to patch-bomb needlessly so thought we'd ask first :)

thanks,
-serge

Re: [C/R v20][PATCH 00/96] Linux Checkpoint-Restart - v20

[Andrew Morton]

On Thu, 1 Apr 2010 18:37:10 -0500
"Serge E. Hallyn" <serue@us.ibm.com> wrote:

> Quoting Oren Laadan (orenl@cs.columbia.edu):
> > Hi Andrew,
> > 
> > Following up on the thread on the checkpoint-restart patch set
> > (http://lkml.org/lkml/2010/3/1/422), the following series is the
> > latest checkpoint/restart, based on 2.6.33.
> > 
> > The first 20 patches are cleanups and prepartion for c/r; they
> > are followed by the actual c/r code.
> > 
> > Please apply to -mm, and let us know if there is any way we can
> > help.
> 
> Hi Andrew,
> 
> Oren sent v20 of the checkpoint/restart patchset out two weeks ago.
> We've addressed some feedback from linux-fsdevel and added network and
> pid namespace support.  So we could resend again now.  However we also
> have a bigger patchset in the works which is feature-neutral, but moves
> all the code out of linux-2.6/checkpoint/ and next to the code it
> affects.  I ancitipate #ifdef clashes though, so we'll
> need to do quite a bit of various-config-and-arch testing of the new
> code layout.  If you're at a good point to pull it, we can resend the
> code as is now so as to get some wider testing exposure. Or, if you prefer,
> we can wait until after the code move in case that would be seen as more
> amenable to meaningful review.
> 

I guess the final product would be better.  It sounds like it'll have
the added benefit of making the various interested parties pay more
attention, too ;)