[PATCH] fs/gfs2: mark struct *_operations const

[PATCH] fs/gfs2: mark struct *_operations const

[Denis Cheng]

these struct *_operations are all method tables, thus should be const.

Signed-off-by: Denis Cheng <crquan@gmail.com>
---
 fs/gfs2/eaops.c        |    8 ++++----
 fs/gfs2/eaops.h        |    4 ++--
 fs/gfs2/glock.c        |    2 +-
 fs/gfs2/ops_dentry.c   |    3 +--
 fs/gfs2/ops_dentry.h   |    2 +-
 fs/gfs2/ops_vm.c       |    4 ++--
 fs/gfs2/ops_vm.h       |    4 ++--
 include/linux/dcache.h |    2 +-
 include/linux/mm.h     |    2 +-
 9 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/fs/gfs2/eaops.c b/fs/gfs2/eaops.c
index 1ab3e9d..aa8dbf3 100644
--- a/fs/gfs2/eaops.c
+++ b/fs/gfs2/eaops.c
@@ -200,28 +200,28 @@ static int security_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
 	return gfs2_ea_remove_i(ip, er);
 }
 
-static struct gfs2_eattr_operations gfs2_user_eaops = {
+static const struct gfs2_eattr_operations gfs2_user_eaops = {
 	.eo_get = user_eo_get,
 	.eo_set = user_eo_set,
 	.eo_remove = user_eo_remove,
 	.eo_name = "user",
 };
 
-struct gfs2_eattr_operations gfs2_system_eaops = {
+const struct gfs2_eattr_operations gfs2_system_eaops = {
 	.eo_get = system_eo_get,
 	.eo_set = system_eo_set,
 	.eo_remove = system_eo_remove,
 	.eo_name = "system",
 };
 
-static struct gfs2_eattr_operations gfs2_security_eaops = {
+static const struct gfs2_eattr_operations gfs2_security_eaops = {
 	.eo_get = security_eo_get,
 	.eo_set = security_eo_set,
 	.eo_remove = security_eo_remove,
 	.eo_name = "security",
 };
 
-struct gfs2_eattr_operations *gfs2_ea_ops[] = {
+const struct gfs2_eattr_operations *gfs2_ea_ops[] = {
 	NULL,
 	&gfs2_user_eaops,
 	&gfs2_system_eaops,
diff --git a/fs/gfs2/eaops.h b/fs/gfs2/eaops.h
index 508b4f7..da2f7fb 100644
--- a/fs/gfs2/eaops.h
+++ b/fs/gfs2/eaops.h
@@ -22,9 +22,9 @@ struct gfs2_eattr_operations {
 
 unsigned int gfs2_ea_name2type(const char *name, const char **truncated_name);
 
-extern struct gfs2_eattr_operations gfs2_system_eaops;
+extern const struct gfs2_eattr_operations gfs2_system_eaops;
 
-extern struct gfs2_eattr_operations *gfs2_ea_ops[];
+extern const struct gfs2_eattr_operations *gfs2_ea_ops[];
 
 #endif /* __EAOPS_DOT_H__ */
 
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 3f0974e..00fe234 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2095,7 +2095,7 @@ static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
 	return 0;
 }
 
-static struct seq_operations gfs2_glock_seq_ops = {
+static const struct seq_operations gfs2_glock_seq_ops = {
 	.start = gfs2_glock_seq_start,
 	.next  = gfs2_glock_seq_next,
 	.stop  = gfs2_glock_seq_stop,
diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
index 793e334..1bdf016 100644
--- a/fs/gfs2/ops_dentry.c
+++ b/fs/gfs2/ops_dentry.c
@@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
 	return 0;
 }
 
-struct dentry_operations gfs2_dops = {
+const struct dentry_operations gfs2_dops = {
 	.d_revalidate = gfs2_drevalidate,
 	.d_hash = gfs2_dhash,
 };
-
diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
index 5caa3db..668a6bc 100644
--- a/fs/gfs2/ops_dentry.h
+++ b/fs/gfs2/ops_dentry.h
@@ -12,6 +12,6 @@
 
 #include <linux/dcache.h>
 
-extern struct dentry_operations gfs2_dops;
+extern const struct dentry_operations gfs2_dops;
 
 #endif /* __OPS_DENTRY_DOT_H__ */
diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
index 927d739..baa3b20 100644
--- a/fs/gfs2/ops_vm.c
+++ b/fs/gfs2/ops_vm.c
@@ -159,11 +159,11 @@ out:
 	return ret;
 }
 
-struct vm_operations_struct gfs2_vm_ops_private = {
+const struct vm_operations_struct gfs2_vm_ops_private = {
 	.fault = gfs2_private_fault,
 };
 
-struct vm_operations_struct gfs2_vm_ops_sharewrite = {
+const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 	.fault = gfs2_sharewrite_fault,
 };
 
diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
index 4ae8f43..cfefd2d 100644
--- a/fs/gfs2/ops_vm.h
+++ b/fs/gfs2/ops_vm.h
@@ -12,7 +12,7 @@
 
 #include <linux/mm.h>
 
-extern struct vm_operations_struct gfs2_vm_ops_private;
-extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
+extern const struct vm_operations_struct gfs2_vm_ops_private;
+extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
 
 #endif /* __OPS_VM_DOT_H__ */
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index aab53df..9cd948e 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -104,7 +104,7 @@ struct dentry {
 	struct list_head d_subdirs;	/* our children */
 	struct list_head d_alias;	/* inode alias list */
 	unsigned long d_time;		/* used by d_revalidate */
-	struct dentry_operations *d_op;
+	const struct dentry_operations *d_op;
 	struct super_block *d_sb;	/* The root of the dentry tree */
 	void *d_fsdata;			/* fs-specific data */
 #ifdef CONFIG_PROFILING
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 655094d..c91b684 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -96,7 +96,7 @@ struct vm_area_struct {
 	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
 
 	/* Function pointers to deal with this struct. */
-	struct vm_operations_struct * vm_ops;
+	const struct vm_operations_struct * vm_ops;
 
 	/* Information about our backing store: */
 	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
-- 
1.5.2.2

[Cluster-devel] Re: [PATCH] fs/gfs2: mark struct *_operations const

[Steven Whitehouse]

Hi,

On Tue, 2007-07-31 at 13:46 +0800, Denis Cheng wrote:
> these struct *_operations are all method tables, thus should be const.
> 
> Signed-off-by: Denis Cheng <crquan@gmail.com>
> ---
>  fs/gfs2/eaops.c        |    8 ++++----
>  fs/gfs2/eaops.h        |    4 ++--
>  fs/gfs2/glock.c        |    2 +-
>  fs/gfs2/ops_dentry.c   |    3 +--
>  fs/gfs2/ops_dentry.h   |    2 +-
>  fs/gfs2/ops_vm.c       |    4 ++--
>  fs/gfs2/ops_vm.h       |    4 ++--
>  include/linux/dcache.h |    2 +-
>  include/linux/mm.h     |    2 +-
>  9 files changed, 15 insertions(+), 16 deletions(-)
> 

In general this looks good, however where you have made changes in the
two include files dcache.h and mm.h be aware that other filesystems also
use these and I suspect there are more places to change than just gfs2.
Can you do a test build with all filesystems enabled to ensure that
you've got all the places which can then be marked const? OCFS2, to take
one example, has a vm_operations_struct which would need to be updated
on that basis at least.

In fact if you can break this up into a patch which affects only gfs2
(which I can apply right away) and a patch which affects the core, plus
updates for the various filesytems that would probably make things
easier from the merging point of view. Since the latter would affect
multiple filesystems, it would make sense to push it through -mm rather
than for me to put it in my git tree,

Steve.

> diff --git a/fs/gfs2/eaops.c b/fs/gfs2/eaops.c
> index 1ab3e9d..aa8dbf3 100644
> --- a/fs/gfs2/eaops.c
> +++ b/fs/gfs2/eaops.c
> @@ -200,28 +200,28 @@ static int security_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
>  	return gfs2_ea_remove_i(ip, er);
>  }
>  
> -static struct gfs2_eattr_operations gfs2_user_eaops = {
> +static const struct gfs2_eattr_operations gfs2_user_eaops = {
>  	.eo_get = user_eo_get,
>  	.eo_set = user_eo_set,
>  	.eo_remove = user_eo_remove,
>  	.eo_name = "user",
>  };
>  
> -struct gfs2_eattr_operations gfs2_system_eaops = {
> +const struct gfs2_eattr_operations gfs2_system_eaops = {
>  	.eo_get = system_eo_get,
>  	.eo_set = system_eo_set,
>  	.eo_remove = system_eo_remove,
>  	.eo_name = "system",
>  };
>  
> -static struct gfs2_eattr_operations gfs2_security_eaops = {
> +static const struct gfs2_eattr_operations gfs2_security_eaops = {
>  	.eo_get = security_eo_get,
>  	.eo_set = security_eo_set,
>  	.eo_remove = security_eo_remove,
>  	.eo_name = "security",
>  };
>  
> -struct gfs2_eattr_operations *gfs2_ea_ops[] = {
> +const struct gfs2_eattr_operations *gfs2_ea_ops[] = {
>  	NULL,
>  	&gfs2_user_eaops,
>  	&gfs2_system_eaops,
> diff --git a/fs/gfs2/eaops.h b/fs/gfs2/eaops.h
> index 508b4f7..da2f7fb 100644
> --- a/fs/gfs2/eaops.h
> +++ b/fs/gfs2/eaops.h
> @@ -22,9 +22,9 @@ struct gfs2_eattr_operations {
>  
>  unsigned int gfs2_ea_name2type(const char *name, const char **truncated_name);
>  
> -extern struct gfs2_eattr_operations gfs2_system_eaops;
> +extern const struct gfs2_eattr_operations gfs2_system_eaops;
>  
> -extern struct gfs2_eattr_operations *gfs2_ea_ops[];
> +extern const struct gfs2_eattr_operations *gfs2_ea_ops[];
>  
>  #endif /* __EAOPS_DOT_H__ */
>  
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index 3f0974e..00fe234 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -2095,7 +2095,7 @@ static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
>  	return 0;
>  }
>  
> -static struct seq_operations gfs2_glock_seq_ops = {
> +static const struct seq_operations gfs2_glock_seq_ops = {
>  	.start = gfs2_glock_seq_start,
>  	.next  = gfs2_glock_seq_next,
>  	.stop  = gfs2_glock_seq_stop,
> diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
> index 793e334..1bdf016 100644
> --- a/fs/gfs2/ops_dentry.c
> +++ b/fs/gfs2/ops_dentry.c
> @@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
>  	return 0;
>  }
>  
> -struct dentry_operations gfs2_dops = {
> +const struct dentry_operations gfs2_dops = {
>  	.d_revalidate = gfs2_drevalidate,
>  	.d_hash = gfs2_dhash,
>  };
> -
> diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
> index 5caa3db..668a6bc 100644
> --- a/fs/gfs2/ops_dentry.h
> +++ b/fs/gfs2/ops_dentry.h
> @@ -12,6 +12,6 @@
>  
>  #include <linux/dcache.h>
>  
> -extern struct dentry_operations gfs2_dops;
> +extern const struct dentry_operations gfs2_dops;
>  
>  #endif /* __OPS_DENTRY_DOT_H__ */
> diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
> index 927d739..baa3b20 100644
> --- a/fs/gfs2/ops_vm.c
> +++ b/fs/gfs2/ops_vm.c
> @@ -159,11 +159,11 @@ out:
>  	return ret;
>  }
>  
> -struct vm_operations_struct gfs2_vm_ops_private = {
> +const struct vm_operations_struct gfs2_vm_ops_private = {
>  	.fault = gfs2_private_fault,
>  };
>  
> -struct vm_operations_struct gfs2_vm_ops_sharewrite = {
> +const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
>  	.fault = gfs2_sharewrite_fault,
>  };
>  
> diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
> index 4ae8f43..cfefd2d 100644
> --- a/fs/gfs2/ops_vm.h
> +++ b/fs/gfs2/ops_vm.h
> @@ -12,7 +12,7 @@
>  
>  #include <linux/mm.h>
>  
> -extern struct vm_operations_struct gfs2_vm_ops_private;
> -extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
> +extern const struct vm_operations_struct gfs2_vm_ops_private;
> +extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
>  
>  #endif /* __OPS_VM_DOT_H__ */
> diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> index aab53df..9cd948e 100644
> --- a/include/linux/dcache.h
> +++ b/include/linux/dcache.h
> @@ -104,7 +104,7 @@ struct dentry {
>  	struct list_head d_subdirs;	/* our children */
>  	struct list_head d_alias;	/* inode alias list */
>  	unsigned long d_time;		/* used by d_revalidate */
> -	struct dentry_operations *d_op;
> +	const struct dentry_operations *d_op;
>  	struct super_block *d_sb;	/* The root of the dentry tree */
>  	void *d_fsdata;			/* fs-specific data */
>  #ifdef CONFIG_PROFILING
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 655094d..c91b684 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -96,7 +96,7 @@ struct vm_area_struct {
>  	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
>  
>  	/* Function pointers to deal with this struct. */
> -	struct vm_operations_struct * vm_ops;
> +	const struct vm_operations_struct * vm_ops;
>  
>  	/* Information about our backing store: */
>  	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE

Re: [PATCH] fs/gfs2: mark struct *_operations const

[Steven Whitehouse]

Hi,

On Tue, 2007-07-31 at 13:46 +0800, Denis Cheng wrote:
> these struct *_operations are all method tables, thus should be const.
> 
> Signed-off-by: Denis Cheng <crquan@gmail.com>
> ---
>  fs/gfs2/eaops.c        |    8 ++++----
>  fs/gfs2/eaops.h        |    4 ++--
>  fs/gfs2/glock.c        |    2 +-
>  fs/gfs2/ops_dentry.c   |    3 +--
>  fs/gfs2/ops_dentry.h   |    2 +-
>  fs/gfs2/ops_vm.c       |    4 ++--
>  fs/gfs2/ops_vm.h       |    4 ++--
>  include/linux/dcache.h |    2 +-
>  include/linux/mm.h     |    2 +-
>  9 files changed, 15 insertions(+), 16 deletions(-)
> 

In general this looks good, however where you have made changes in the
two include files dcache.h and mm.h be aware that other filesystems also
use these and I suspect there are more places to change than just gfs2.
Can you do a test build with all filesystems enabled to ensure that
you've got all the places which can then be marked const? OCFS2, to take
one example, has a vm_operations_struct which would need to be updated
on that basis at least.

In fact if you can break this up into a patch which affects only gfs2
(which I can apply right away) and a patch which affects the core, plus
updates for the various filesytems that would probably make things
easier from the merging point of view. Since the latter would affect
multiple filesystems, it would make sense to push it through -mm rather
than for me to put it in my git tree,

Steve.

> diff --git a/fs/gfs2/eaops.c b/fs/gfs2/eaops.c
> index 1ab3e9d..aa8dbf3 100644
> --- a/fs/gfs2/eaops.c
> +++ b/fs/gfs2/eaops.c
> @@ -200,28 +200,28 @@ static int security_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
>  	return gfs2_ea_remove_i(ip, er);
>  }
>  
> -static struct gfs2_eattr_operations gfs2_user_eaops = {
> +static const struct gfs2_eattr_operations gfs2_user_eaops = {
>  	.eo_get = user_eo_get,
>  	.eo_set = user_eo_set,
>  	.eo_remove = user_eo_remove,
>  	.eo_name = "user",
>  };
>  
> -struct gfs2_eattr_operations gfs2_system_eaops = {
> +const struct gfs2_eattr_operations gfs2_system_eaops = {
>  	.eo_get = system_eo_get,
>  	.eo_set = system_eo_set,
>  	.eo_remove = system_eo_remove,
>  	.eo_name = "system",
>  };
>  
> -static struct gfs2_eattr_operations gfs2_security_eaops = {
> +static const struct gfs2_eattr_operations gfs2_security_eaops = {
>  	.eo_get = security_eo_get,
>  	.eo_set = security_eo_set,
>  	.eo_remove = security_eo_remove,
>  	.eo_name = "security",
>  };
>  
> -struct gfs2_eattr_operations *gfs2_ea_ops[] = {
> +const struct gfs2_eattr_operations *gfs2_ea_ops[] = {
>  	NULL,
>  	&gfs2_user_eaops,
>  	&gfs2_system_eaops,
> diff --git a/fs/gfs2/eaops.h b/fs/gfs2/eaops.h
> index 508b4f7..da2f7fb 100644
> --- a/fs/gfs2/eaops.h
> +++ b/fs/gfs2/eaops.h
> @@ -22,9 +22,9 @@ struct gfs2_eattr_operations {
>  
>  unsigned int gfs2_ea_name2type(const char *name, const char **truncated_name);
>  
> -extern struct gfs2_eattr_operations gfs2_system_eaops;
> +extern const struct gfs2_eattr_operations gfs2_system_eaops;
>  
> -extern struct gfs2_eattr_operations *gfs2_ea_ops[];
> +extern const struct gfs2_eattr_operations *gfs2_ea_ops[];
>  
>  #endif /* __EAOPS_DOT_H__ */
>  
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index 3f0974e..00fe234 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -2095,7 +2095,7 @@ static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
>  	return 0;
>  }
>  
> -static struct seq_operations gfs2_glock_seq_ops = {
> +static const struct seq_operations gfs2_glock_seq_ops = {
>  	.start = gfs2_glock_seq_start,
>  	.next  = gfs2_glock_seq_next,
>  	.stop  = gfs2_glock_seq_stop,
> diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
> index 793e334..1bdf016 100644
> --- a/fs/gfs2/ops_dentry.c
> +++ b/fs/gfs2/ops_dentry.c
> @@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
>  	return 0;
>  }
>  
> -struct dentry_operations gfs2_dops = {
> +const struct dentry_operations gfs2_dops = {
>  	.d_revalidate = gfs2_drevalidate,
>  	.d_hash = gfs2_dhash,
>  };
> -
> diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
> index 5caa3db..668a6bc 100644
> --- a/fs/gfs2/ops_dentry.h
> +++ b/fs/gfs2/ops_dentry.h
> @@ -12,6 +12,6 @@
>  
>  #include <linux/dcache.h>
>  
> -extern struct dentry_operations gfs2_dops;
> +extern const struct dentry_operations gfs2_dops;
>  
>  #endif /* __OPS_DENTRY_DOT_H__ */
> diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
> index 927d739..baa3b20 100644
> --- a/fs/gfs2/ops_vm.c
> +++ b/fs/gfs2/ops_vm.c
> @@ -159,11 +159,11 @@ out:
>  	return ret;
>  }
>  
> -struct vm_operations_struct gfs2_vm_ops_private = {
> +const struct vm_operations_struct gfs2_vm_ops_private = {
>  	.fault = gfs2_private_fault,
>  };
>  
> -struct vm_operations_struct gfs2_vm_ops_sharewrite = {
> +const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
>  	.fault = gfs2_sharewrite_fault,
>  };
>  
> diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
> index 4ae8f43..cfefd2d 100644
> --- a/fs/gfs2/ops_vm.h
> +++ b/fs/gfs2/ops_vm.h
> @@ -12,7 +12,7 @@
>  
>  #include <linux/mm.h>
>  
> -extern struct vm_operations_struct gfs2_vm_ops_private;
> -extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
> +extern const struct vm_operations_struct gfs2_vm_ops_private;
> +extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
>  
>  #endif /* __OPS_VM_DOT_H__ */
> diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> index aab53df..9cd948e 100644
> --- a/include/linux/dcache.h
> +++ b/include/linux/dcache.h
> @@ -104,7 +104,7 @@ struct dentry {
>  	struct list_head d_subdirs;	/* our children */
>  	struct list_head d_alias;	/* inode alias list */
>  	unsigned long d_time;		/* used by d_revalidate */
> -	struct dentry_operations *d_op;
> +	const struct dentry_operations *d_op;
>  	struct super_block *d_sb;	/* The root of the dentry tree */
>  	void *d_fsdata;			/* fs-specific data */
>  #ifdef CONFIG_PROFILING
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 655094d..c91b684 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -96,7 +96,7 @@ struct vm_area_struct {
>  	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
>  
>  	/* Function pointers to deal with this struct. */
> -	struct vm_operations_struct * vm_ops;
> +	const struct vm_operations_struct * vm_ops;
>  
>  	/* Information about our backing store: */
>  	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE

Re: [PATCH] fs/gfs2: mark struct *_operations const

[rae l]

On 7/31/07, Steven Whitehouse <swhiteho@redhat.com> wrote:
> Hi,
>
> On Tue, 2007-07-31 at 13:46 +0800, Denis Cheng wrote:
> > these struct *_operations are all method tables, thus should be const.
> >
> > Signed-off-by: Denis Cheng <crquan@gmail.com>
> > ---
> >  fs/gfs2/eaops.c        |    8 ++++----
> >  fs/gfs2/eaops.h        |    4 ++--
> >  fs/gfs2/glock.c        |    2 +-
> >  fs/gfs2/ops_dentry.c   |    3 +--
> >  fs/gfs2/ops_dentry.h   |    2 +-
> >  fs/gfs2/ops_vm.c       |    4 ++--
> >  fs/gfs2/ops_vm.h       |    4 ++--
> >  include/linux/dcache.h |    2 +-
> >  include/linux/mm.h     |    2 +-
> >  9 files changed, 15 insertions(+), 16 deletions(-)
> >
>
> In general this looks good, however where you have made changes in the
> two include files dcache.h and mm.h be aware that other filesystems also
> use these and I suspect there are more places to change than just gfs2.
> Can you do a test build with all filesystems enabled to ensure that
> you've got all the places which can then be marked const? OCFS2, to take
> one example, has a vm_operations_struct which would need to be updated
> on that basis at least.
>
> In fact if you can break this up into a patch which affects only gfs2
> (which I can apply right away) and a patch which affects the core, plus
> updates for the various filesytems that would probably make things
> easier from the merging point of view. Since the latter would affect
> multiple filesystems, it would make sense to push it through -mm rather
> than for me to put it in my git tree,
>
> Steve.
>

I think so. But I've tested it under x86(pentium4) with allyesconfig
and allmodconfig, the compilication process of the kernel looked very
quiet.
$ make mrproper
$ make allyesconfig
$ make fs/

$ make mrproper
$ make allmodconfig
$ make fs/

and the ocfs2 didn't complain.

However, I'll split it into two patches and resend them later.

[PATCH 1/3] fs/gfs2: mark struct *_operations const

[Denis Cheng]

these struct *_operations are all method tables, thus should be const.

Signed-off-by: Denis Cheng <crquan@gmail.com>
---
 fs/gfs2/eaops.c |    8 ++++----
 fs/gfs2/eaops.h |    4 ++--
 fs/gfs2/glock.c |    2 +-
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/gfs2/eaops.c b/fs/gfs2/eaops.c
index 1ab3e9d..aa8dbf3 100644
--- a/fs/gfs2/eaops.c
+++ b/fs/gfs2/eaops.c
@@ -200,28 +200,28 @@ static int security_eo_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
 	return gfs2_ea_remove_i(ip, er);
 }
 
-static struct gfs2_eattr_operations gfs2_user_eaops = {
+static const struct gfs2_eattr_operations gfs2_user_eaops = {
 	.eo_get = user_eo_get,
 	.eo_set = user_eo_set,
 	.eo_remove = user_eo_remove,
 	.eo_name = "user",
 };
 
-struct gfs2_eattr_operations gfs2_system_eaops = {
+const struct gfs2_eattr_operations gfs2_system_eaops = {
 	.eo_get = system_eo_get,
 	.eo_set = system_eo_set,
 	.eo_remove = system_eo_remove,
 	.eo_name = "system",
 };
 
-static struct gfs2_eattr_operations gfs2_security_eaops = {
+static const struct gfs2_eattr_operations gfs2_security_eaops = {
 	.eo_get = security_eo_get,
 	.eo_set = security_eo_set,
 	.eo_remove = security_eo_remove,
 	.eo_name = "security",
 };
 
-struct gfs2_eattr_operations *gfs2_ea_ops[] = {
+const struct gfs2_eattr_operations *gfs2_ea_ops[] = {
 	NULL,
 	&gfs2_user_eaops,
 	&gfs2_system_eaops,
diff --git a/fs/gfs2/eaops.h b/fs/gfs2/eaops.h
index 508b4f7..da2f7fb 100644
--- a/fs/gfs2/eaops.h
+++ b/fs/gfs2/eaops.h
@@ -22,9 +22,9 @@ struct gfs2_eattr_operations {
 
 unsigned int gfs2_ea_name2type(const char *name, const char **truncated_name);
 
-extern struct gfs2_eattr_operations gfs2_system_eaops;
+extern const struct gfs2_eattr_operations gfs2_system_eaops;
 
-extern struct gfs2_eattr_operations *gfs2_ea_ops[];
+extern const struct gfs2_eattr_operations *gfs2_ea_ops[];
 
 #endif /* __EAOPS_DOT_H__ */
 
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 3f0974e..00fe234 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2095,7 +2095,7 @@ static int gfs2_glock_seq_show(struct seq_file *file, void *iter_ptr)
 	return 0;
 }
 
-static struct seq_operations gfs2_glock_seq_ops = {
+static const struct seq_operations gfs2_glock_seq_ops = {
 	.start = gfs2_glock_seq_start,
 	.next  = gfs2_glock_seq_next,
 	.stop  = gfs2_glock_seq_stop,
-- 
1.5.2.2

[PATCH 2/3] fs/gfs2: use the declaration of gfs2_dops in the header file instead

[Denis Cheng]

Signed-off-by: Denis Cheng <crquan@gmail.com>
---
 fs/gfs2/ops_fstype.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index cf5aa50..9a5e840 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -28,6 +28,7 @@
 #include "lm.h"
 #include "mount.h"
 #include "ops_fstype.h"
+#include "ops_dentry.h"
 #include "ops_super.h"
 #include "recovery.h"
 #include "rgrp.h"
@@ -38,8 +39,6 @@
 #define DO 0
 #define UNDO 1
 
-extern struct dentry_operations gfs2_dops;
-
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
 {
 	struct gfs2_sbd *sdp;
-- 
1.5.2.2

[PATCH 3/3] fs/gfs2: also mark struct {dentry,vm}_operations const

[Denis Cheng]

these struct *_operations are all method tables, thus should be const.

Signed-off-by: Denis Cheng <crquan@gmail.com>
---
 fs/gfs2/ops_dentry.c   |    3 +--
 fs/gfs2/ops_dentry.h   |    2 +-
 fs/gfs2/ops_vm.c       |    4 ++--
 fs/gfs2/ops_vm.h       |    4 ++--
 include/linux/dcache.h |    2 +-
 include/linux/mm.h     |    2 +-
 6 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
index 793e334..1bdf016 100644
--- a/fs/gfs2/ops_dentry.c
+++ b/fs/gfs2/ops_dentry.c
@@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
 	return 0;
 }
 
-struct dentry_operations gfs2_dops = {
+const struct dentry_operations gfs2_dops = {
 	.d_revalidate = gfs2_drevalidate,
 	.d_hash = gfs2_dhash,
 };
-
diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
index 5caa3db..668a6bc 100644
--- a/fs/gfs2/ops_dentry.h
+++ b/fs/gfs2/ops_dentry.h
@@ -12,6 +12,6 @@
 
 #include <linux/dcache.h>
 
-extern struct dentry_operations gfs2_dops;
+extern const struct dentry_operations gfs2_dops;
 
 #endif /* __OPS_DENTRY_DOT_H__ */
diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
index 927d739..baa3b20 100644
--- a/fs/gfs2/ops_vm.c
+++ b/fs/gfs2/ops_vm.c
@@ -159,11 +159,11 @@ out:
 	return ret;
 }
 
-struct vm_operations_struct gfs2_vm_ops_private = {
+const struct vm_operations_struct gfs2_vm_ops_private = {
 	.fault = gfs2_private_fault,
 };
 
-struct vm_operations_struct gfs2_vm_ops_sharewrite = {
+const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
 	.fault = gfs2_sharewrite_fault,
 };
 
diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
index 4ae8f43..cfefd2d 100644
--- a/fs/gfs2/ops_vm.h
+++ b/fs/gfs2/ops_vm.h
@@ -12,7 +12,7 @@
 
 #include <linux/mm.h>
 
-extern struct vm_operations_struct gfs2_vm_ops_private;
-extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
+extern const struct vm_operations_struct gfs2_vm_ops_private;
+extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
 
 #endif /* __OPS_VM_DOT_H__ */
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index aab53df..9cd948e 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -104,7 +104,7 @@ struct dentry {
 	struct list_head d_subdirs;	/* our children */
 	struct list_head d_alias;	/* inode alias list */
 	unsigned long d_time;		/* used by d_revalidate */
-	struct dentry_operations *d_op;
+	const struct dentry_operations *d_op;
 	struct super_block *d_sb;	/* The root of the dentry tree */
 	void *d_fsdata;			/* fs-specific data */
 #ifdef CONFIG_PROFILING
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 655094d..c91b684 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -96,7 +96,7 @@ struct vm_area_struct {
 	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
 
 	/* Function pointers to deal with this struct. */
-	struct vm_operations_struct * vm_ops;
+	const struct vm_operations_struct * vm_ops;
 
 	/* Information about our backing store: */
 	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
-- 
1.5.2.2

[Cluster-devel] Re: [PATCH 3/3] fs/gfs2: also mark struct {dentry, vm}_operations const

[Steven Whitehouse]

Hi,

On Tue, 2007-07-31 at 18:31 +0800, Denis Cheng wrote:
> these struct *_operations are all method tables, thus should be const.
> 
> Signed-off-by: Denis Cheng <crquan@gmail.com>
> ---
>  fs/gfs2/ops_dentry.c   |    3 +--
>  fs/gfs2/ops_dentry.h   |    2 +-
>  fs/gfs2/ops_vm.c       |    4 ++--
>  fs/gfs2/ops_vm.h       |    4 ++--
>  include/linux/dcache.h |    2 +-
>  include/linux/mm.h     |    2 +-
>  6 files changed, 8 insertions(+), 9 deletions(-)
> 
I've applied the first two patches in the series, but I'm still not
quite sure about this one. Even though it might not produce any warnings
there are still other filesystems to change, and I think it would be a
good plan to convert them all and CC the relevant maintainers.

Steve.



> diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
> index 793e334..1bdf016 100644
> --- a/fs/gfs2/ops_dentry.c
> +++ b/fs/gfs2/ops_dentry.c
> @@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
>  	return 0;
>  }
>  
> -struct dentry_operations gfs2_dops = {
> +const struct dentry_operations gfs2_dops = {
>  	.d_revalidate = gfs2_drevalidate,
>  	.d_hash = gfs2_dhash,
>  };
> -
> diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
> index 5caa3db..668a6bc 100644
> --- a/fs/gfs2/ops_dentry.h
> +++ b/fs/gfs2/ops_dentry.h
> @@ -12,6 +12,6 @@
>  
>  #include <linux/dcache.h>
>  
> -extern struct dentry_operations gfs2_dops;
> +extern const struct dentry_operations gfs2_dops;
>  
>  #endif /* __OPS_DENTRY_DOT_H__ */
> diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
> index 927d739..baa3b20 100644
> --- a/fs/gfs2/ops_vm.c
> +++ b/fs/gfs2/ops_vm.c
> @@ -159,11 +159,11 @@ out:
>  	return ret;
>  }
>  
> -struct vm_operations_struct gfs2_vm_ops_private = {
> +const struct vm_operations_struct gfs2_vm_ops_private = {
>  	.fault = gfs2_private_fault,
>  };
>  
> -struct vm_operations_struct gfs2_vm_ops_sharewrite = {
> +const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
>  	.fault = gfs2_sharewrite_fault,
>  };
>  
> diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
> index 4ae8f43..cfefd2d 100644
> --- a/fs/gfs2/ops_vm.h
> +++ b/fs/gfs2/ops_vm.h
> @@ -12,7 +12,7 @@
>  
>  #include <linux/mm.h>
>  
> -extern struct vm_operations_struct gfs2_vm_ops_private;
> -extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
> +extern const struct vm_operations_struct gfs2_vm_ops_private;
> +extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
>  
>  #endif /* __OPS_VM_DOT_H__ */
> diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> index aab53df..9cd948e 100644
> --- a/include/linux/dcache.h
> +++ b/include/linux/dcache.h
> @@ -104,7 +104,7 @@ struct dentry {
>  	struct list_head d_subdirs;	/* our children */
>  	struct list_head d_alias;	/* inode alias list */
>  	unsigned long d_time;		/* used by d_revalidate */
> -	struct dentry_operations *d_op;
> +	const struct dentry_operations *d_op;
>  	struct super_block *d_sb;	/* The root of the dentry tree */
>  	void *d_fsdata;			/* fs-specific data */
>  #ifdef CONFIG_PROFILING
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 655094d..c91b684 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -96,7 +96,7 @@ struct vm_area_struct {
>  	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
>  
>  	/* Function pointers to deal with this struct. */
> -	struct vm_operations_struct * vm_ops;
> +	const struct vm_operations_struct * vm_ops;
>  
>  	/* Information about our backing store: */
>  	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE

Re: [PATCH 3/3] fs/gfs2: also mark struct {dentry,vm}_operations const

[Steven Whitehouse]

Hi,

On Tue, 2007-07-31 at 18:31 +0800, Denis Cheng wrote:
> these struct *_operations are all method tables, thus should be const.
> 
> Signed-off-by: Denis Cheng <crquan@gmail.com>
> ---
>  fs/gfs2/ops_dentry.c   |    3 +--
>  fs/gfs2/ops_dentry.h   |    2 +-
>  fs/gfs2/ops_vm.c       |    4 ++--
>  fs/gfs2/ops_vm.h       |    4 ++--
>  include/linux/dcache.h |    2 +-
>  include/linux/mm.h     |    2 +-
>  6 files changed, 8 insertions(+), 9 deletions(-)
> 
I've applied the first two patches in the series, but I'm still not
quite sure about this one. Even though it might not produce any warnings
there are still other filesystems to change, and I think it would be a
good plan to convert them all and CC the relevant maintainers.

Steve.



> diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
> index 793e334..1bdf016 100644
> --- a/fs/gfs2/ops_dentry.c
> +++ b/fs/gfs2/ops_dentry.c
> @@ -108,8 +108,7 @@ static int gfs2_dhash(struct dentry *dentry, struct qstr *str)
>  	return 0;
>  }
>  
> -struct dentry_operations gfs2_dops = {
> +const struct dentry_operations gfs2_dops = {
>  	.d_revalidate = gfs2_drevalidate,
>  	.d_hash = gfs2_dhash,
>  };
> -
> diff --git a/fs/gfs2/ops_dentry.h b/fs/gfs2/ops_dentry.h
> index 5caa3db..668a6bc 100644
> --- a/fs/gfs2/ops_dentry.h
> +++ b/fs/gfs2/ops_dentry.h
> @@ -12,6 +12,6 @@
>  
>  #include <linux/dcache.h>
>  
> -extern struct dentry_operations gfs2_dops;
> +extern const struct dentry_operations gfs2_dops;
>  
>  #endif /* __OPS_DENTRY_DOT_H__ */
> diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
> index 927d739..baa3b20 100644
> --- a/fs/gfs2/ops_vm.c
> +++ b/fs/gfs2/ops_vm.c
> @@ -159,11 +159,11 @@ out:
>  	return ret;
>  }
>  
> -struct vm_operations_struct gfs2_vm_ops_private = {
> +const struct vm_operations_struct gfs2_vm_ops_private = {
>  	.fault = gfs2_private_fault,
>  };
>  
> -struct vm_operations_struct gfs2_vm_ops_sharewrite = {
> +const struct vm_operations_struct gfs2_vm_ops_sharewrite = {
>  	.fault = gfs2_sharewrite_fault,
>  };
>  
> diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
> index 4ae8f43..cfefd2d 100644
> --- a/fs/gfs2/ops_vm.h
> +++ b/fs/gfs2/ops_vm.h
> @@ -12,7 +12,7 @@
>  
>  #include <linux/mm.h>
>  
> -extern struct vm_operations_struct gfs2_vm_ops_private;
> -extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
> +extern const struct vm_operations_struct gfs2_vm_ops_private;
> +extern const struct vm_operations_struct gfs2_vm_ops_sharewrite;
>  
>  #endif /* __OPS_VM_DOT_H__ */
> diff --git a/include/linux/dcache.h b/include/linux/dcache.h
> index aab53df..9cd948e 100644
> --- a/include/linux/dcache.h
> +++ b/include/linux/dcache.h
> @@ -104,7 +104,7 @@ struct dentry {
>  	struct list_head d_subdirs;	/* our children */
>  	struct list_head d_alias;	/* inode alias list */
>  	unsigned long d_time;		/* used by d_revalidate */
> -	struct dentry_operations *d_op;
> +	const struct dentry_operations *d_op;
>  	struct super_block *d_sb;	/* The root of the dentry tree */
>  	void *d_fsdata;			/* fs-specific data */
>  #ifdef CONFIG_PROFILING
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 655094d..c91b684 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -96,7 +96,7 @@ struct vm_area_struct {
>  	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
>  
>  	/* Function pointers to deal with this struct. */
> -	struct vm_operations_struct * vm_ops;
> +	const struct vm_operations_struct * vm_ops;
>  
>  	/* Information about our backing store: */
>  	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE