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authorRafael J. Wysocki <rjw@sisk.pl>2006-01-06 00:16:37 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 08:33:43 -0800
commit3a291a20bd6fcfafb2109031f0760a0d3e92ecd7 (patch)
tree6c034471da9b2aac77b9810af640bb7a515cb299
parentca0aec0f7a94bf9f07fefa8bfd23282d4e8ceb8a (diff)
downloadlinux-linaro-stable-3a291a20bd6fcfafb2109031f0760a0d3e92ecd7.tar.gz
[PATCH] mm: add a new function (needed for swap suspend)
This adds the function get_swap_page_of_type() allowing us to specify an index in swap_info[] and select a swap_info_struct structure to be used for allocating a swap page. This function (or another one of similar functionality) will be necessary for implementing the image-writing part of swsusp in the user space.  It can also be used for simplifying the current in-kernel implementation of the image-writing part of swsusp. 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>
-rw-r--r--include/linux/swap.h1
-rw-r--r--mm/swapfile.c20
2 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index bd6641784107..556617bcf7ac 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -209,6 +209,7 @@ extern unsigned int nr_swapfiles;
extern struct swap_info_struct swap_info[];
extern void si_swapinfo(struct sysinfo *);
extern swp_entry_t get_swap_page(void);
+extern swp_entry_t get_swap_page_of_type(int type);
extern int swap_duplicate(swp_entry_t);
extern int valid_swaphandles(swp_entry_t, unsigned long *);
extern void swap_free(swp_entry_t);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index edafeace301f..6da4b28b896b 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -211,6 +211,26 @@ noswap:
return (swp_entry_t) {0};
}
+swp_entry_t get_swap_page_of_type(int type)
+{
+ struct swap_info_struct *si;
+ pgoff_t offset;
+
+ spin_lock(&swap_lock);
+ si = swap_info + type;
+ if (si->flags & SWP_WRITEOK) {
+ nr_swap_pages--;
+ offset = scan_swap_map(si);
+ if (offset) {
+ spin_unlock(&swap_lock);
+ return swp_entry(type, offset);
+ }
+ nr_swap_pages++;
+ }
+ spin_unlock(&swap_lock);
+ return (swp_entry_t) {0};
+}
+
static struct swap_info_struct * swap_info_get(swp_entry_t entry)
{
struct swap_info_struct * p;