Re: [RFC 06/15] PM / Hibernate: swap, remove swap_map_handle usages

Pavel Machek
2010-03-24T20:33:30Z

On Tue 2010-03-23 17:17:34, Jiri Slaby wrote:
> Some code, which will be moved out of swap.c, needs know nothing about
> swap. There will be also other than swap writers later, so that it
> won't make sense at all.
>
> Make it a global static in swap.c as a singleton.

I guess I just dislike global static. Logically, methods do operate on
handles, so...

I don't see a point and I do not think the change is an improvement.
Pavel

> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
> Cc: Nigel Cunningham <ncunningham@crca.org.au>
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> ---
> kernel/power/swap.c | 58 +++++++++++++++++++++++++-------------------------
> 1 files changed, 29 insertions(+), 29 deletions(-)
>
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index 2edf742..ac1a351 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -70,6 +70,7 @@ struct swsusp_header {
> char sig[10];
> } __attribute__((packed));
>
> +static struct swap_map_handle swap_map_handle;
> static struct swsusp_header *swsusp_header;
>
> /**
> @@ -267,8 +268,9 @@ static void release_swap_writer(struct swap_map_handle *handle)
> handle->cur = NULL;
> }
>
> -static int get_swap_writer(struct swap_map_handle *handle)
> +static int get_swap_writer(void)
> {
> + struct swap_map_handle *handle = &swap_map_handle;
> int ret;
>
> ret = swsusp_swap_check();
> @@ -278,6 +280,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
> "swapon -a.\n");
> return ret;
> }
> + memset(handle, 0, sizeof(*handle));
> handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
> if (!handle->cur) {
> ret = -ENOMEM;
> @@ -298,9 +301,9 @@ err_close:
> return ret;
> }
>
> -static int swap_write_page(struct swap_map_handle *handle, void *buf,
> - struct bio **bio_chain)
> +static int swap_write_page(void *buf, struct bio **bio_chain)
> {
> + struct swap_map_handle *handle = &swap_map_handle;
> int error = 0;
> sector_t offset;
>
> @@ -338,9 +341,10 @@ static int flush_swap_writer(struct swap_map_handle *handle)
> return -EINVAL;
> }
>
> -static int put_swap_writer(struct swap_map_handle *handle,
> - unsigned int flags, int error)
> +static int put_swap_writer(unsigned int flags, int error)
> {
> + struct swap_map_handle *handle = &swap_map_handle;
> +
> if (!error) {
> flush_swap_writer(handle);
> printk(KERN_INFO "PM: S");
> @@ -360,8 +364,7 @@ static int put_swap_writer(struct swap_map_handle *handle,
> * save_image - save the suspend image data
> */
>
> -static int save_image(struct swap_map_handle *handle,
> - struct snapshot_handle *snapshot,
> +static int save_image(struct snapshot_handle *snapshot,
> unsigned int nr_to_write)
> {
> unsigned int m;
> @@ -384,7 +387,7 @@ static int save_image(struct swap_map_handle *handle,
> ret = snapshot_read_next(snapshot);
> if (ret <= 0)
> break;
> - ret = swap_write_page(handle, data_of(*snapshot), &bio);
> + ret = swap_write_page(data_of(*snapshot), &bio);
> if (ret)
> break;
> if (!(nr_pages % m))
> @@ -430,14 +433,13 @@ static int enough_swap(unsigned int nr_pages)
>
> int swsusp_write(unsigned int flags)
> {
> - struct swap_map_handle handle;
> struct snapshot_handle snapshot;
> struct swsusp_info *header;
> unsigned long pages;
> int error;
>
> pages = snapshot_get_image_size();
> - error = get_swap_writer(&handle);
> + error = get_swap_writer();
> if (error) {
> printk(KERN_ERR "PM: Cannot get swap writer\n");
> return error;
> @@ -456,11 +458,11 @@ int swsusp_write(unsigned int flags)
> goto out_finish;
> }
> header = (struct swsusp_info *)data_of(snapshot);
> - error = swap_write_page(&handle, header, NULL);
> + error = swap_write_page(header, NULL);
> if (!error)
> - error = save_image(&handle, &snapshot, pages - 1);
> + error = save_image(&snapshot, pages - 1);
> out_finish:
> - error = put_swap_writer(&handle, flags, error);
> + error = put_swap_writer(flags, error);
> return error;
> }
>
> @@ -476,9 +478,9 @@ static void release_swap_reader(struct swap_map_handle *handle)
> handle->cur = NULL;
> }
>
> -static int get_swap_reader(struct swap_map_handle *handle,
> - unsigned int *flags_p)
> +static int get_swap_reader(unsigned int *flags_p)
> {
> + struct swap_map_handle *handle = &swap_map_handle;
> int error;
>
> *flags_p = swsusp_header->flags;
> @@ -486,6 +488,7 @@ static int get_swap_reader(struct swap_map_handle *handle,
> if (!swsusp_header->image) /* how can this happen? */
> return -EINVAL;
>
> + memset(handle, 0, sizeof(*handle));
> handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH);
> if (!handle->cur)
> return -ENOMEM;
> @@ -499,9 +502,9 @@ static int get_swap_reader(struct swap_map_handle *handle,
> return 0;
> }
>
> -static int swap_read_page(struct swap_map_handle *handle, void *buf,
> - struct bio **bio_chain)
> +static int swap_read_page(void *buf, struct bio **bio_chain)
> {
> + struct swap_map_handle *handle = &swap_map_handle;
> sector_t offset;
> int error;
>
> @@ -525,22 +528,20 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf,
> return error;
> }
>
> -static int put_swap_reader(struct swap_map_handle *handle)
> +static int put_swap_reader(void)
> {
> - release_swap_reader(handle);
> + release_swap_reader(&swap_map_handle);
>
> return 0;
> }
>
> /**
> - * load_image - load the image using the swap map handle
> + * load_image - load the image
> * @handle and the snapshot handle @snapshot
> * (assume there are @nr_pages pages to load)
> */
>
> -static int load_image(struct swap_map_handle *handle,
> - struct snapshot_handle *snapshot,
> - unsigned int nr_to_read)
> +static int load_image(struct snapshot_handle *snapshot, unsigned int nr_to_read)
> {
> unsigned int m;
> int error = 0;
> @@ -562,7 +563,7 @@ static int load_image(struct swap_map_handle *handle,
> error = snapshot_write_next(snapshot);
> if (error <= 0)
> break;
> - error = swap_read_page(handle, data_of(*snapshot), &bio);
> + error = swap_read_page(data_of(*snapshot), &bio);
> if (error)
> break;
> if (snapshot->sync_read)
> @@ -597,7 +598,6 @@ static int load_image(struct swap_map_handle *handle,
> int swsusp_read(unsigned int *flags_p)
> {
> int error;
> - struct swap_map_handle handle;
> struct snapshot_handle snapshot;
> struct swsusp_info *header;
>
> @@ -606,14 +606,14 @@ int swsusp_read(unsigned int *flags_p)
> if (error < PAGE_SIZE)
> return error < 0 ? error : -EFAULT;
> header = (struct swsusp_info *)data_of(snapshot);
> - error = get_swap_reader(&handle, flags_p);
> + error = get_swap_reader(flags_p);
> if (error)
> goto end;
> if (!error)
> - error = swap_read_page(&handle, header, NULL);
> + error = swap_read_page(header, NULL);
> if (!error)
> - error = load_image(&handle, &snapshot, header->pages - 1);
> - put_swap_reader(&handle);
> + error = load_image(&snapshot, header->pages - 1);
> + put_swap_reader();
> end:
> if (!error)
> pr_debug("PM: Image successfully loaded\n");

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html