diff options
Diffstat (limited to 'kernel/power/swap.c')
-rw-r--r-- | kernel/power/swap.c | 333 |
1 files changed, 139 insertions, 194 deletions
diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 66824d71983..b0bb2177839 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -29,6 +29,40 @@ #define SWSUSP_SIG "S1SUSPEND" +/* + * The swap map is a data structure used for keeping track of each page + * written to a swap partition. It consists of many swap_map_page + * structures that contain each an array of MAP_PAGE_SIZE swap entries. + * These structures are stored on the swap and linked together with the + * help of the .next_swap member. + * + * The swap map is created during suspend. The swap map pages are + * allocated and populated one at a time, so we only need one memory + * page to set up the entire structure. + * + * During resume we also only need to use one swap_map_page structure + * at a time. + */ + +#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) + +struct swap_map_page { + sector_t entries[MAP_PAGE_ENTRIES]; + sector_t next_swap; +}; + +/** + * The swap_map_handle structure is used for handling swap in + * a file-alike way + */ + +struct swap_map_handle { + struct swap_map_page *cur; + sector_t cur_swap; + sector_t first_sector; + unsigned int k; +}; + struct swsusp_header { char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; sector_t image; @@ -145,110 +179,24 @@ int swsusp_swap_in_use(void) */ static unsigned short root_swap = 0xffff; -static struct block_device *resume_bdev; - -/** - * submit - submit BIO request. - * @rw: READ or WRITE. - * @off physical offset of page. - * @page: page we're reading or writing. - * @bio_chain: list of pending biod (for async reading) - * - * Straight from the textbook - allocate and initialize the bio. - * If we're reading, make sure the page is marked as dirty. - * Then submit it and, if @bio_chain == NULL, wait. - */ -static int submit(int rw, pgoff_t page_off, struct page *page, - struct bio **bio_chain) -{ - const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); - struct bio *bio; - - bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1); - bio->bi_sector = page_off * (PAGE_SIZE >> 9); - bio->bi_bdev = resume_bdev; - bio->bi_end_io = end_swap_bio_read; - - if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { - printk(KERN_ERR "PM: Adding page to bio failed at %ld\n", - page_off); - bio_put(bio); - return -EFAULT; - } - - lock_page(page); - bio_get(bio); - - if (bio_chain == NULL) { - submit_bio(bio_rw, bio); - wait_on_page_locked(page); - if (rw == READ) - bio_set_pages_dirty(bio); - bio_put(bio); - } else { - if (rw == READ) - get_page(page); /* These pages are freed later */ - bio->bi_private = *bio_chain; - *bio_chain = bio; - submit_bio(bio_rw, bio); - } - return 0; -} - -static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain) -{ - return submit(READ, page_off, virt_to_page(addr), bio_chain); -} - -static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain) -{ - return submit(WRITE, page_off, virt_to_page(addr), bio_chain); -} - -static int wait_on_bio_chain(struct bio **bio_chain) -{ - struct bio *bio; - struct bio *next_bio; - int ret = 0; - - if (bio_chain == NULL) - return 0; - - bio = *bio_chain; - if (bio == NULL) - return 0; - while (bio) { - struct page *page; - - next_bio = bio->bi_private; - page = bio->bi_io_vec[0].bv_page; - wait_on_page_locked(page); - if (!PageUptodate(page) || PageError(page)) - ret = -EIO; - put_page(page); - bio_put(bio); - bio = next_bio; - } - *bio_chain = NULL; - return ret; -} +struct block_device *hib_resume_bdev; /* * Saving part */ -static int mark_swapfiles(sector_t start, unsigned int flags) +static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) { int error; - bio_read_page(swsusp_resume_block, swsusp_header, NULL); + hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); memcpy(swsusp_header->sig,SWSUSP_SIG, 10); - swsusp_header->image = start; + swsusp_header->image = handle->first_sector; swsusp_header->flags = flags; - error = bio_write_page(swsusp_resume_block, + error = hib_bio_write_page(swsusp_resume_block, swsusp_header, NULL); } else { printk(KERN_ERR "PM: Swap header not found!\n"); @@ -260,25 +208,26 @@ static int mark_swapfiles(sector_t start, unsigned int flags) /** * swsusp_swap_check - check if the resume device is a swap device * and get its index (if so) + * + * This is called before saving image */ - -static int swsusp_swap_check(void) /* This is called before saving image */ +static int swsusp_swap_check(void) { int res; res = swap_type_of(swsusp_resume_device, swsusp_resume_block, - &resume_bdev); + &hib_resume_bdev); if (res < 0) return res; root_swap = res; - res = blkdev_get(resume_bdev, FMODE_WRITE); + res = blkdev_get(hib_resume_bdev, FMODE_WRITE); if (res) return res; - res = set_blocksize(resume_bdev, PAGE_SIZE); + res = set_blocksize(hib_resume_bdev, PAGE_SIZE); if (res < 0) - blkdev_put(resume_bdev, FMODE_WRITE); + blkdev_put(hib_resume_bdev, FMODE_WRITE); return res; } @@ -309,42 +258,9 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain) } else { src = buf; } - return bio_write_page(offset, src, bio_chain); + return hib_bio_write_page(offset, src, bio_chain); } -/* - * The swap map is a data structure used for keeping track of each page - * written to a swap partition. It consists of many swap_map_page - * structures that contain each an array of MAP_PAGE_SIZE swap entries. - * These structures are stored on the swap and linked together with the - * help of the .next_swap member. - * - * The swap map is created during suspend. The swap map pages are - * allocated and populated one at a time, so we only need one memory - * page to set up the entire structure. - * - * During resume we also only need to use one swap_map_page structure - * at a time. - */ - -#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) - -struct swap_map_page { - sector_t entries[MAP_PAGE_ENTRIES]; - sector_t next_swap; -}; - -/** - * The swap_map_handle structure is used for handling swap in - * a file-alike way - */ - -struct swap_map_handle { - struct swap_map_page *cur; - sector_t cur_swap; - unsigned int k; -}; - static void release_swap_writer(struct swap_map_handle *handle) { if (handle->cur) @@ -354,16 +270,33 @@ static void release_swap_writer(struct swap_map_handle *handle) static int get_swap_writer(struct swap_map_handle *handle) { + int ret; + + ret = swsusp_swap_check(); + if (ret) { + if (ret != -ENOSPC) + printk(KERN_ERR "PM: Cannot find swap device, try " + "swapon -a.\n"); + return ret; + } handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); - if (!handle->cur) - return -ENOMEM; + if (!handle->cur) { + ret = -ENOMEM; + goto err_close; + } handle->cur_swap = alloc_swapdev_block(root_swap); if (!handle->cur_swap) { - release_swap_writer(handle); - return -ENOSPC; + ret = -ENOSPC; + goto err_rel; } handle->k = 0; + handle->first_sector = handle->cur_swap; return 0; +err_rel: + release_swap_writer(handle); +err_close: + swsusp_close(FMODE_WRITE); + return ret; } static int swap_write_page(struct swap_map_handle *handle, void *buf, @@ -380,7 +313,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf, return error; handle->cur->entries[handle->k++] = offset; if (handle->k >= MAP_PAGE_ENTRIES) { - error = wait_on_bio_chain(bio_chain); + error = hib_wait_on_bio_chain(bio_chain); if (error) goto out; offset = alloc_swapdev_block(root_swap); @@ -406,6 +339,24 @@ static int flush_swap_writer(struct swap_map_handle *handle) return -EINVAL; } +static int swap_writer_finish(struct swap_map_handle *handle, + unsigned int flags, int error) +{ + if (!error) { + flush_swap_writer(handle); + printk(KERN_INFO "PM: S"); + error = mark_swapfiles(handle, flags); + printk("|\n"); + } + + if (error) + free_all_swap_pages(root_swap); + release_swap_writer(handle); + swsusp_close(FMODE_WRITE); + + return error; +} + /** * save_image - save the suspend image data */ @@ -431,7 +382,7 @@ static int save_image(struct swap_map_handle *handle, bio = NULL; do_gettimeofday(&start); while (1) { - ret = snapshot_read_next(snapshot, PAGE_SIZE); + ret = snapshot_read_next(snapshot); if (ret <= 0) break; ret = swap_write_page(handle, data_of(*snapshot), &bio); @@ -441,7 +392,7 @@ static int save_image(struct swap_map_handle *handle, printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } - err2 = wait_on_bio_chain(&bio); + err2 = hib_wait_on_bio_chain(&bio); do_gettimeofday(&stop); if (!ret) ret = err2; @@ -483,50 +434,34 @@ int swsusp_write(unsigned int flags) struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; + unsigned long pages; int error; - error = swsusp_swap_check(); + pages = snapshot_get_image_size(); + error = get_swap_writer(&handle); if (error) { - printk(KERN_ERR "PM: Cannot find swap device, try " - "swapon -a.\n"); + printk(KERN_ERR "PM: Cannot get swap writer\n"); return error; } + if (!enough_swap(pages)) { + printk(KERN_ERR "PM: Not enough free swap\n"); + error = -ENOSPC; + goto out_finish; + } memset(&snapshot, 0, sizeof(struct snapshot_handle)); - error = snapshot_read_next(&snapshot, PAGE_SIZE); + error = snapshot_read_next(&snapshot); if (error < PAGE_SIZE) { if (error >= 0) error = -EFAULT; - goto out; + goto out_finish; } header = (struct swsusp_info *)data_of(snapshot); - if (!enough_swap(header->pages)) { - printk(KERN_ERR "PM: Not enough free swap\n"); - error = -ENOSPC; - goto out; - } - error = get_swap_writer(&handle); - if (!error) { - sector_t start = handle.cur_swap; - - error = swap_write_page(&handle, header, NULL); - if (!error) - error = save_image(&handle, &snapshot, - header->pages - 1); - - if (!error) { - flush_swap_writer(&handle); - printk(KERN_INFO "PM: S"); - error = mark_swapfiles(start, flags); - printk("|\n"); - } - } - if (error) - free_all_swap_pages(root_swap); - - release_swap_writer(&handle); - out: - swsusp_close(FMODE_WRITE); + error = swap_write_page(&handle, header, NULL); + if (!error) + error = save_image(&handle, &snapshot, pages - 1); +out_finish: + error = swap_writer_finish(&handle, flags, error); return error; } @@ -542,18 +477,21 @@ static void release_swap_reader(struct swap_map_handle *handle) handle->cur = NULL; } -static int get_swap_reader(struct swap_map_handle *handle, sector_t start) +static int get_swap_reader(struct swap_map_handle *handle, + unsigned int *flags_p) { int error; - if (!start) + *flags_p = swsusp_header->flags; + + if (!swsusp_header->image) /* how can this happen? */ return -EINVAL; handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); if (!handle->cur) return -ENOMEM; - error = bio_read_page(start, handle->cur, NULL); + error = hib_bio_read_page(swsusp_header->image, handle->cur, NULL); if (error) { release_swap_reader(handle); return error; @@ -573,21 +511,28 @@ static int swap_read_page(struct swap_map_handle *handle, void *buf, offset = handle->cur->entries[handle->k]; if (!offset) return -EFAULT; - error = bio_read_page(offset, buf, bio_chain); + error = hib_bio_read_page(offset, buf, bio_chain); if (error) return error; if (++handle->k >= MAP_PAGE_ENTRIES) { - error = wait_on_bio_chain(bio_chain); + error = hib_wait_on_bio_chain(bio_chain); handle->k = 0; offset = handle->cur->next_swap; if (!offset) release_swap_reader(handle); else if (!error) - error = bio_read_page(offset, handle->cur, NULL); + error = hib_bio_read_page(offset, handle->cur, NULL); } return error; } +static int swap_reader_finish(struct swap_map_handle *handle) +{ + release_swap_reader(handle); + + return 0; +} + /** * load_image - load the image using the swap map handle * @handle and the snapshot handle @snapshot @@ -615,21 +560,21 @@ static int load_image(struct swap_map_handle *handle, bio = NULL; do_gettimeofday(&start); for ( ; ; ) { - error = snapshot_write_next(snapshot, PAGE_SIZE); + error = snapshot_write_next(snapshot); if (error <= 0) break; error = swap_read_page(handle, data_of(*snapshot), &bio); if (error) break; if (snapshot->sync_read) - error = wait_on_bio_chain(&bio); + error = hib_wait_on_bio_chain(&bio); if (error) break; if (!(nr_pages % m)) printk("\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } - err2 = wait_on_bio_chain(&bio); + err2 = hib_wait_on_bio_chain(&bio); do_gettimeofday(&stop); if (!error) error = err2; @@ -657,20 +602,20 @@ int swsusp_read(unsigned int *flags_p) struct snapshot_handle snapshot; struct swsusp_info *header; - *flags_p = swsusp_header->flags; - memset(&snapshot, 0, sizeof(struct snapshot_handle)); - error = snapshot_write_next(&snapshot, PAGE_SIZE); + error = snapshot_write_next(&snapshot); if (error < PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); - error = get_swap_reader(&handle, swsusp_header->image); + error = get_swap_reader(&handle, flags_p); + if (error) + goto end; if (!error) error = swap_read_page(&handle, header, NULL); if (!error) error = load_image(&handle, &snapshot, header->pages - 1); - release_swap_reader(&handle); - + swap_reader_finish(&handle); +end: if (!error) pr_debug("PM: Image successfully loaded\n"); else @@ -686,11 +631,11 @@ int swsusp_check(void) { int error; - resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); - if (!IS_ERR(resume_bdev)) { - set_blocksize(resume_bdev, PAGE_SIZE); + hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); + if (!IS_ERR(hib_resume_bdev)) { + set_blocksize(hib_resume_bdev, PAGE_SIZE); memset(swsusp_header, 0, PAGE_SIZE); - error = bio_read_page(swsusp_resume_block, + error = hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); if (error) goto put; @@ -698,7 +643,7 @@ int swsusp_check(void) if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) { memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); /* Reset swap signature now */ - error = bio_write_page(swsusp_resume_block, + error = hib_bio_write_page(swsusp_resume_block, swsusp_header, NULL); } else { error = -EINVAL; @@ -706,11 +651,11 @@ int swsusp_check(void) put: if (error) - blkdev_put(resume_bdev, FMODE_READ); + blkdev_put(hib_resume_bdev, FMODE_READ); else pr_debug("PM: Signature found, resuming\n"); } else { - error = PTR_ERR(resume_bdev); + error = PTR_ERR(hib_resume_bdev); } if (error) @@ -725,12 +670,12 @@ put: void swsusp_close(fmode_t mode) { - if (IS_ERR(resume_bdev)) { + if (IS_ERR(hib_resume_bdev)) { pr_debug("PM: Image device not initialised\n"); return; } - blkdev_put(resume_bdev, mode); + blkdev_put(hib_resume_bdev, mode); } static int swsusp_header_init(void) |