Hibernation: Introduce SNAPSHOT_GET_IMAGE_SIZE ioctl (af508b34) · Commits · 戴 / test

Documentation/power/userland-swsusp.txt

+5 −7

Original line number	Diff line number	Diff line
		@@ -54,6 +54,8 @@ SNAPSHOT_SET_IMAGE_SIZE - set the preferred maximum size of the image
		this number, but if it turns out to be impossible, the kernel will
		create the smallest image possible)

		SNAPSHOT_GET_IMAGE_SIZE - return the actual size of the hibernation image

		SNAPSHOT_AVAIL_SWAP - return the amount of available swap in bytes (the last
		argument should be a pointer to an unsigned int variable that will
		contain the result if the call is successful).
		@@ -136,13 +138,9 @@ required, as they can use, for example, a special (blank) suspend partition or
		a file on a partition that is unmounted before SNAPSHOT_ATOMIC_SNAPSHOT and
		mounted afterwards.

		These utilities SHOULD NOT make any assumptions regarding the ordering of
		data within the snapshot image, except for the image header that MAY be
		assumed to start with an swsusp_info structure, as specified in
		kernel/power/power.h. This structure MAY be used by the userland utilities
		to obtain some information about the snapshot image, such as the size
		of the snapshot image, including the metadata and the header itself,
		contained in the .size member of swsusp_info.
		These utilities MUST NOT make any assumptions regarding the ordering of
		data within the snapshot image. The contents of the image are entirely owned
		by the kernel and its structure may be changed in future kernel releases.

		The snapshot image MUST be written to the kernel unaltered (ie. all of the image
		data, metadata and header MUST be written in _exactly_ the same amount, form

kernel/power/power.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -128,6 +128,7 @@ struct snapshot_handle {
		#define data_of(handle) ((handle).buffer + (handle).buf_offset)

		extern unsigned int snapshot_additional_pages(struct zone *zone);
		extern unsigned long snapshot_get_image_size(void);
		extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
		extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
		extern void snapshot_write_finalize(struct snapshot_handle *handle);
		@@ -158,7 +159,8 @@ struct resume_swap_area {
		#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
		#define SNAPSHOT_SET_SWAP_AREA _IOW(SNAPSHOT_IOC_MAGIC, 13, \
		struct resume_swap_area)
		#define SNAPSHOT_IOC_MAXNR 13
		#define SNAPSHOT_GET_IMAGE_SIZE _IOR(SNAPSHOT_IOC_MAGIC, 14, loff_t)
		#define SNAPSHOT_IOC_MAXNR 14

		#define PMOPS_PREPARE 1
		#define PMOPS_ENTER 2

kernel/power/snapshot.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1264,12 +1264,17 @@ static char check_image_kernel(struct swsusp_info info)
		}
		#endif /* CONFIG_ARCH_HIBERNATION_HEADER */

		unsigned long snapshot_get_image_size(void)
		{
		return nr_copy_pages + nr_meta_pages + 1;
		}

		static int init_header(struct swsusp_info *info)
		{
		memset(info, 0, sizeof(struct swsusp_info));
		info->num_physpages = num_physpages;
		info->image_pages = nr_copy_pages;
		info->pages = nr_copy_pages + nr_meta_pages + 1;
		info->pages = snapshot_get_image_size();
		info->size = info->pages;
		info->size <<= PAGE_SHIFT;
		return init_header_complete(info);

kernel/power/user.c

+14 −4

Original line number	Diff line number	Diff line
		@@ -133,7 +133,7 @@ static int snapshot_ioctl(struct inode inode, struct file filp,
		{
		int error = 0;
		struct snapshot_data *data;
		loff_t avail;
		loff_t size;
		sector_t offset;

		if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
		@@ -210,10 +210,20 @@ static int snapshot_ioctl(struct inode inode, struct file filp,
		image_size = arg;
		break;

		case SNAPSHOT_GET_IMAGE_SIZE:
		if (!data->ready) {
		error = -ENODATA;
		break;
		}
		size = snapshot_get_image_size();
		size <<= PAGE_SHIFT;
		error = put_user(size, (loff_t __user *)arg);
		break;

		case SNAPSHOT_AVAIL_SWAP:
		avail = count_swap_pages(data->swap, 1);
		avail <<= PAGE_SHIFT;
		error = put_user(avail, (loff_t __user *)arg);
		size = count_swap_pages(data->swap, 1);
		size <<= PAGE_SHIFT;
		error = put_user(size, (loff_t __user *)arg);
		break;

		case SNAPSHOT_GET_SWAP_PAGE:

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