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authorRafael J. Wysocki <rjw@sisk.pl>2006-03-23 03:00:03 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-23 07:38:07 -0800
commit6e1819d615f24ce0726a7d0bd3dd0152d7b21654 (patch)
treeabc68747446e8241a1a7103882b9f6b6e24fa274 /kernel/power/snapshot.c
parent543cc27d09643640cbc34189c03a40beb8227aef (diff)
[PATCH] swsusp: userland interface
This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions.  Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/power/snapshot.c')
-rw-r--r--kernel/power/snapshot.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index cc349437fb7..0036955357e 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -37,6 +37,7 @@
struct pbe *pagedir_nosave;
static unsigned int nr_copy_pages;
static unsigned int nr_meta_pages;
+static unsigned long *buffer;
#ifdef CONFIG_HIGHMEM
unsigned int count_highmem_pages(void)
@@ -389,7 +390,7 @@ struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed
free_pagedir(pblist);
pblist = NULL;
} else
- create_pbe_list(pblist, nr_pages);
+ create_pbe_list(pblist, nr_pages);
return pblist;
}
@@ -418,6 +419,7 @@ void swsusp_free(void)
nr_copy_pages = 0;
nr_meta_pages = 0;
pagedir_nosave = NULL;
+ buffer = NULL;
}
@@ -523,6 +525,8 @@ static void init_header(struct swsusp_info *info)
info->cpus = num_online_cpus();
info->image_pages = nr_copy_pages;
info->pages = nr_copy_pages + nr_meta_pages + 1;
+ info->size = info->pages;
+ info->size <<= PAGE_SHIFT;
}
/**
@@ -568,8 +572,6 @@ static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pb
int snapshot_read_next(struct snapshot_handle *handle, size_t count)
{
- static unsigned long *buffer;
-
if (handle->page > nr_meta_pages + nr_copy_pages)
return 0;
if (!buffer) {
@@ -774,7 +776,6 @@ static int create_image(struct snapshot_handle *handle)
int snapshot_write_next(struct snapshot_handle *handle, size_t count)
{
- static unsigned long *buffer;
int error = 0;
if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages)