Re: [PATCH 3/12] exofs: add ->sync_fs

[Boaz Harrosh <bharrosh@panasas.com>]

On 06/08/2009 11:03 AM, Christoph Hellwig wrote:
> Add a ->sync_fs method for data integrity syncs, and reimplement
> ->write_super ontop of it.
> 
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Thanks 

> 
> Index: vfs-2.6/fs/exofs/super.c
> ===================================================================
> --- vfs-2.6.orig/fs/exofs/super.c	2009-06-05 15:59:08.521843147 +0200
> +++ vfs-2.6/fs/exofs/super.c	2009-06-05 16:02:20.687950326 +0200
> @@ -200,18 +200,18 @@ static const struct export_operations ex
>  /*
>   * Write the superblock to the OSD
>   */
> -static void exofs_write_super(struct super_block *sb)
> +static int exofs_sync_fs(struct super_block *sb, int wait)
>  {
>  	struct exofs_sb_info *sbi;
>  	struct exofs_fscb *fscb;
>  	struct osd_request *or;
>  	struct osd_obj_id obj;
> -	int ret;
> +	int ret = -ENOMEM;
>  
>  	fscb = kzalloc(sizeof(struct exofs_fscb), GFP_KERNEL);
>  	if (!fscb) {
>  		EXOFS_ERR("exofs_write_super: memory allocation failed.\n");
> -		return;
> +		return -ENOMEM;
>  	}
>  
>  	lock_super(sb);
> @@ -249,6 +249,15 @@ out:
>  	unlock_kernel();
>  	unlock_super(sb);
>  	kfree(fscb);
> +	return ret;
> +}
> +
> +static void exofs_write_super(struct super_block *sb)
> +{
> +	if (!(sb->s_flags & MS_RDONLY))
> +		exofs_sync_fs(sb, 1);
> +	else
> +		sb->s_dirt = 0;

I never tested read-only mounts. Unlike ext3 (Journals)
Read-only mount should also work with:

		BUG_ON(sb->s_dirt)

As the actual journal is on the OSD targets, and is abstracted
away form the file system.

>  }
>  
>  /*
> @@ -493,6 +502,7 @@ static const struct super_operations exo
>  	.delete_inode   = exofs_delete_inode,
>  	.put_super      = exofs_put_super,
>  	.write_super    = exofs_write_super,
> +	.sync_fs	= exofs_sync_fs,
>  	.statfs         = exofs_statfs,
>  };
>  
> --
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