diff options
| author | Rafael J. Wysocki <rjw@sisk.pl> | 2006-01-06 00:16:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-06 08:33:43 -0800 |
| commit | 3a291a20bd6fcfafb2109031f0760a0d3e92ecd7 (patch) | |
| tree | 6c034471da9b2aac77b9810af640bb7a515cb299 | |
| parent | ca0aec0f7a94bf9f07fefa8bfd23282d4e8ceb8a (diff) | |
[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.h | 1 | ||||
| -rw-r--r-- | mm/swapfile.c | 20 |
2 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index bd664178410..556617bcf7a 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 edafeace301..6da4b28b896 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; |