From 3a291a20bd6fcfafb2109031f0760a0d3e92ecd7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 6 Jan 2006 00:16:37 -0800 Subject: [PATCH] [PATCH] mm: add a new function (needed for swap suspend) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 1 + mm/swapfile.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) 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; -- 2.20.1