On Thu 30-07-15 13:48:02, Dongsheng Yang wrote:
> This patch refactors the original get_super_thawed to get a common
> helper function of __get_super_thawed. Then take the use of
> __get_super_thawed, we can implement get_super_cdev_thawed easily.
>
> Signed-off-by: Dongsheng Yang <yangds.fnst@xxxxxxxxxxxxxx>
> ---
> fs/super.c | 29 +++++++++++++++++++++++++----
> include/linux/fs.h | 1 +
> 2 files changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/fs/super.c b/fs/super.c
> index 4c56dff..0e11412 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -629,18 +629,20 @@ struct super_block *get_super_cdev(struct cdev *cdev)
> EXPORT_SYMBOL(get_super_cdev);
>
> /**
> - * get_super_thawed - get thawed superblock of a device
> - * @bdev: device to get the superblock for
> + * __get_super_thawed - get thawed superblock
> + * @func: function pointer to get superblock by key
> + * @key: key to find superblock
> *
> * Scans the superblock list and finds the superblock of the file system
> * mounted on the device. The superblock is returned once it is thawed
> * (or immediately if it was not frozen). %NULL is returned if no match
> * is found.
> */
> -struct super_block *get_super_thawed(struct block_device *bdev)
> +static struct super_block *__get_super_thawed(
> + struct super_block *(*func)(void *), void *key)
> {
> while (1) {
> - struct super_block *s = get_super(bdev);
> + struct super_block *s = func(key);
It would seem more obvious (and consistent with get_super() class of
functions) if you passed in a comparison function and a key and then call
from here:
s = __get_super(compare, key);
Also you would avoid some of the ugly typecasting below.
Honza
> if (!s || s->s_writers.frozen == SB_UNFROZEN)
> return s;
> up_read(&s->s_umount);
> @@ -649,9 +651,28 @@ struct super_block *get_super_thawed(struct block_device *bdev)
> put_super(s);
> }
> }
> +
> +/**
> + * get_super_thawed - get thawed superblock of a device
> + * @bdev: device to get the superblock for
> + */
> +struct super_block *get_super_thawed(struct block_device *bdev)
> +{
> + return __get_super_thawed((struct super_block *(*)(void *))get_super, bdev);
> +}
> EXPORT_SYMBOL(get_super_thawed);
>
> /**
> + * get_super_cdev_thawed - get thawed superblock of a char device
> + * @cdev: device to get the superblock for
> + */
> +struct super_block *get_super_cdev_thawed(struct cdev *cdev)
> +{
> + return __get_super_thawed((struct super_block *(*)(void *))get_super_cdev, cdev);
> +}
> +EXPORT_SYMBOL(get_super_cdev_thawed);
> +
> +/**
> * get_active_super - get an active reference to the superblock of a device
> * @bdev: device to get the superblock for
> *
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index e5ea425a..5c7d789 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2746,6 +2746,7 @@ extern struct file_system_type *get_fs_type(const char *name);
> extern struct super_block *get_super(struct block_device *);
> extern struct super_block *get_super_cdev(struct cdev *);
> extern struct super_block *get_super_thawed(struct block_device *);
> +extern struct super_block *get_super_cdev_thawed(struct cdev *);
> extern struct super_block *get_active_super(struct block_device *bdev);
> extern void drop_super(struct super_block *sb);
> extern void iterate_supers(void (*)(struct super_block *, void *), void *);
> --
> 1.8.4.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
