lkml.org 
[lkml]   [2009]   [Oct]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH 1/9] swap_info: private to swapfile.c
    The swap_info_struct is mostly private to mm/swapfile.c, with only
    one other in-tree user: get_swap_bio(). Adjust its interface to
    map_swap_page(), so that we can then remove get_swap_info_struct().

    But there is a popular user out-of-tree, TuxOnIce: so leave the
    declaration of swap_info_struct in linux/swap.h.

    Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
    ---

    include/linux/swap.h | 3 +--
    mm/page_io.c | 19 +++++++------------
    mm/swapfile.c | 29 +++++++++++++++++------------
    3 files changed, 25 insertions(+), 26 deletions(-)

    --- 2.6.32-rc4/include/linux/swap.h 2009-09-28 00:28:39.000000000 +0100
    +++ si1/include/linux/swap.h 2009-10-14 21:25:58.000000000 +0100
    @@ -317,9 +317,8 @@ extern void swapcache_free(swp_entry_t,
    extern int free_swap_and_cache(swp_entry_t);
    extern int swap_type_of(dev_t, sector_t, struct block_device **);
    extern unsigned int count_swap_pages(int, int);
    -extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
    +extern sector_t map_swap_page(swp_entry_t, struct block_device **);
    extern sector_t swapdev_block(int, pgoff_t);
    -extern struct swap_info_struct *get_swap_info_struct(unsigned);
    extern int reuse_swap_page(struct page *);
    extern int try_to_free_swap(struct page *);
    struct backing_dev_info;
    --- 2.6.32-rc4/mm/page_io.c 2009-09-09 23:13:59.000000000 +0100
    +++ si1/mm/page_io.c 2009-10-14 21:25:58.000000000 +0100
    @@ -19,20 +19,17 @@
    #include <linux/writeback.h>
    #include <asm/pgtable.h>

    -static struct bio *get_swap_bio(gfp_t gfp_flags, pgoff_t index,
    +static struct bio *get_swap_bio(gfp_t gfp_flags,
    struct page *page, bio_end_io_t end_io)
    {
    struct bio *bio;

    bio = bio_alloc(gfp_flags, 1);
    if (bio) {
    - struct swap_info_struct *sis;
    - swp_entry_t entry = { .val = index, };
    -
    - sis = get_swap_info_struct(swp_type(entry));
    - bio->bi_sector = map_swap_page(sis, swp_offset(entry)) *
    - (PAGE_SIZE >> 9);
    - bio->bi_bdev = sis->bdev;
    + swp_entry_t entry;
    + entry.val = page_private(page);
    + bio->bi_sector = map_swap_page(entry, &bio->bi_bdev);
    + bio->bi_sector <<= PAGE_SHIFT - 9;
    bio->bi_io_vec[0].bv_page = page;
    bio->bi_io_vec[0].bv_len = PAGE_SIZE;
    bio->bi_io_vec[0].bv_offset = 0;
    @@ -102,8 +99,7 @@ int swap_writepage(struct page *page, st
    unlock_page(page);
    goto out;
    }
    - bio = get_swap_bio(GFP_NOIO, page_private(page), page,
    - end_swap_bio_write);
    + bio = get_swap_bio(GFP_NOIO, page, end_swap_bio_write);
    if (bio == NULL) {
    set_page_dirty(page);
    unlock_page(page);
    @@ -127,8 +123,7 @@ int swap_readpage(struct page *page)

    VM_BUG_ON(!PageLocked(page));
    VM_BUG_ON(PageUptodate(page));
    - bio = get_swap_bio(GFP_KERNEL, page_private(page), page,
    - end_swap_bio_read);
    + bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read);
    if (bio == NULL) {
    unlock_page(page);
    ret = -ENOMEM;
    --- 2.6.32-rc4/mm/swapfile.c 2009-10-05 04:33:14.000000000 +0100
    +++ si1/mm/swapfile.c 2009-10-14 21:25:58.000000000 +0100
    @@ -1284,12 +1284,22 @@ static void drain_mmlist(void)

    /*
    * Use this swapdev's extent info to locate the (PAGE_SIZE) block which
    - * corresponds to page offset `offset'.
    + * corresponds to page offset `offset'. Note that the type of this function
    + * is sector_t, but it returns page offset into the bdev, not sector offset.
    */
    -sector_t map_swap_page(struct swap_info_struct *sis, pgoff_t offset)
    +sector_t map_swap_page(swp_entry_t entry, struct block_device **bdev)
    {
    - struct swap_extent *se = sis->curr_swap_extent;
    - struct swap_extent *start_se = se;
    + struct swap_info_struct *sis;
    + struct swap_extent *start_se;
    + struct swap_extent *se;
    + pgoff_t offset;
    +
    + sis = swap_info + swp_type(entry);
    + *bdev = sis->bdev;
    +
    + offset = swp_offset(entry);
    + start_se = sis->curr_swap_extent;
    + se = start_se;

    for ( ; ; ) {
    struct list_head *lh;
    @@ -1315,12 +1325,14 @@ sector_t map_swap_page(struct swap_info_
    sector_t swapdev_block(int swap_type, pgoff_t offset)
    {
    struct swap_info_struct *sis;
    + struct block_device *bdev;

    if (swap_type >= nr_swapfiles)
    return 0;

    sis = swap_info + swap_type;
    - return (sis->flags & SWP_WRITEOK) ? map_swap_page(sis, offset) : 0;
    + return (sis->flags & SWP_WRITEOK) ?
    + map_swap_page(swp_entry(swap_type, offset), &bdev) : 0;
    }
    #endif /* CONFIG_HIBERNATION */

    @@ -2160,13 +2172,6 @@ int swapcache_prepare(swp_entry_t entry)
    return __swap_duplicate(entry, SWAP_CACHE);
    }

    -
    -struct swap_info_struct *
    -get_swap_info_struct(unsigned type)
    -{
    - return &swap_info[type];
    -}
    -
    /*
    * swap_lock prevents swap_map being freed. Don't grab an extra
    * reference on the swaphandle, it doesn't matter if it becomes unused.

    \
     
     \ /
      Last update: 2009-10-15 02:57    [W:0.054 / U:0.128 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site