2012-08-16 09:59:53

by Marco Stornelli

Subject: [PATCH 1/8] vfs: remove lock and unlock functions for super block

From: Marco Stornelli <[email protected]>

Remove lock_super and unlock_super from VFS.

Signed-off-by: Marco Stornelli <[email protected]>
---

diff -Nurp linux-3.6-rc1-orig/fs/super.c linux-3.6-rc1/fs/super.c
--- linux-3.6-rc1-orig/fs/super.c 2012-08-16 09:37:35.000000000 +0200
+++ linux-3.6-rc1/fs/super.c 2012-08-16 09:43:46.000000000 +0200
@@ -186,15 +186,8 @@ static struct super_block *alloc_super(s
spin_lock_init(&s->s_inode_lru_lock);
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
- mutex_init(&s->s_lock);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
/*
- * The locking rules for s_lock are up to the
- * filesystem. For example ext3fs has different
- * lock ordering than usbfs:
- */
- lockdep_set_class(&s->s_lock, &type->s_lock_key);
- /*
* sget() can have s_umount recursion.
*
* When it cannot find a suitable sb, it allocates a new
@@ -400,22 +393,6 @@ bool grab_super_passive(struct super_blo
return false;
}
-/*
- * Superblock locking. We really ought to get rid of these two.
- */
-void lock_super(struct super_block * sb)
-{
- mutex_lock(&sb->s_lock);
-}
-
-void unlock_super(struct super_block * sb)
-{
- mutex_unlock(&sb->s_lock);
-}
-
-EXPORT_SYMBOL(lock_super);
-EXPORT_SYMBOL(unlock_super);
-
/**
* generic_shutdown_super - common helper for ->kill_sb()
* @sb: superblock to kill

diff -Nurp linux-3.6-rc1-orig/include/linux/fs.h linux-3.6-rc1/include/linux/fs.h
--- linux-3.6-rc1-orig/include/linux/fs.h 2012-08-16 11:38:42.000000000 +0200
+++ linux-3.6-rc1/include/linux/fs.h 2012-08-16 09:45:18.000000000 +0200
@@ -1504,7 +1504,6 @@ struct super_block {
unsigned long s_magic;
struct dentry *s_root;
struct rw_semaphore s_umount;
- struct mutex s_lock;
int s_count;
atomic_t s_active;
#ifdef CONFIG_SECURITY

2012-08-16 12:26:40

by Boaz Harrosh

Subject: Re: [PATCH 1/8] vfs: remove lock and unlock functions for super block

On 08/16/2012 12:59 PM, Marco Stornelli wrote:

> From: Marco Stornelli <[email protected]>
>
> Remove lock_super and unlock_super from VFS.
>
> Signed-off-by: Marco Stornelli <[email protected]>


You can't remove the lock here. After this patch the tree will
not compile, and will not be bisectable. You must move this patch
to be last.

Each patch should leave the tree compileable and with out any
regressions.

Boaz

> ---
>
> diff -Nurp linux-3.6-rc1-orig/fs/super.c linux-3.6-rc1/fs/super.c
> --- linux-3.6-rc1-orig/fs/super.c 2012-08-16 09:37:35.000000000 +0200
> +++ linux-3.6-rc1/fs/super.c 2012-08-16 09:43:46.000000000 +0200
> @@ -186,15 +186,8 @@ static struct super_block *alloc_super(s
> spin_lock_init(&s->s_inode_lru_lock);
> INIT_LIST_HEAD(&s->s_mounts);
> init_rwsem(&s->s_umount);
> - mutex_init(&s->s_lock);
> lockdep_set_class(&s->s_umount, &type->s_umount_key);
> /*
> - * The locking rules for s_lock are up to the
> - * filesystem. For example ext3fs has different
> - * lock ordering than usbfs:
> - */
> - lockdep_set_class(&s->s_lock, &type->s_lock_key);
> - /*
> * sget() can have s_umount recursion.
> *
> * When it cannot find a suitable sb, it allocates a new
> @@ -400,22 +393,6 @@ bool grab_super_passive(struct super_blo
> return false;
> }
> -/*
> - * Superblock locking. We really ought to get rid of these two.
> - */
> -void lock_super(struct super_block * sb)
> -{
> - mutex_lock(&sb->s_lock);
> -}
> -
> -void unlock_super(struct super_block * sb)
> -{
> - mutex_unlock(&sb->s_lock);
> -}
> -
> -EXPORT_SYMBOL(lock_super);
> -EXPORT_SYMBOL(unlock_super);
> -
> /**
> * generic_shutdown_super - common helper for ->kill_sb()
> * @sb: superblock to kill
>
> diff -Nurp linux-3.6-rc1-orig/include/linux/fs.h linux-3.6-rc1/include/linux/fs.h
> --- linux-3.6-rc1-orig/include/linux/fs.h 2012-08-16 11:38:42.000000000 +0200
> +++ linux-3.6-rc1/include/linux/fs.h 2012-08-16 09:45:18.000000000 +0200
> @@ -1504,7 +1504,6 @@ struct super_block {
> unsigned long s_magic;
> struct dentry *s_root;
> struct rw_semaphore s_umount;
> - struct mutex s_lock;
> int s_count;
> atomic_t s_active;
> #ifdef CONFIG_SECURITY

2012-08-16 16:11:35

by Marco Stornelli

Subject: Re: [PATCH 1/8] vfs: remove lock and unlock functions for super block

Il 16/08/2012 14:26, Boaz Harrosh ha scritto:
> On 08/16/2012 12:59 PM, Marco Stornelli wrote:
>
>> From: Marco Stornelli <[email protected]>
>>
>> Remove lock_super and unlock_super from VFS.
>>
>> Signed-off-by: Marco Stornelli <[email protected]>
>
>
> You can't remove the lock here. After this patch the tree will
> not compile, and will not be bisectable. You must move this patch
> to be last.
>
> Each patch should leave the tree compileable and with out any
> regressions.
>
> Boaz
>

Yep, you're right. I'll resend it in the right order at the end of first
review.

Thanks,

Marco