/* * linux/kernel/power/swap.c * * This file provides functions for reading the suspend image from * and writing it to a swap partition. * * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> * * This file is released under the GPLv2. * */ #include <linux/module.h>#include <linux/smp_lock.h>#include <linux/file.h>#include <linux/utsname.h>#include <linux/version.h>#include <linux/delay.h>#include <linux/bitops.h>#include <linux/genhd.h>#include <linux/device.h>#include <linux/buffer_head.h>#include <linux/bio.h>#include <linux/swap.h>#include <linux/swapops.h>#include <linux/pm.h> #include "power.h" extern char resume_file[]; #define SWSUSP_SIG "S1SUSPEND" static struct swsusp_header { char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)]; swp_entry_t image; char orig_sig[10]; char sig[10];} __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header; /* * Saving part... */ static unsigned short root_swap = 0xffff; static int mark_swapfiles(swp_entry_t start){ int error; rw_swap_page_sync(READ, swp_entry(root_swap, 0), virt_to_page((unsigned long)&swsusp_header)); 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; error = rw_swap_page_sync(WRITE, swp_entry(root_swap, 0), virt_to_page((unsigned long) &swsusp_header)); } else { pr_debug("swsusp: Partition is not swap space.\n"); error = -ENODEV; } return error;} /** * swsusp_swap_check - check if the resume device is a swap device * and get its index (if so) */ static int swsusp_swap_check(void) /* This is called before saving image */{ int res = swap_type_of(swsusp_resume_device); if (res >= 0) { root_swap = res; return 0; } return res;} /** * write_page - Write one page to given swap location. * @buf: Address we're writing. * @offset: Offset of the swap page we're writing to. */ static int write_page(void *buf, unsigned long offset){ swp_entry_t entry; int error = -ENOSPC; if (offset) { entry = swp_entry(root_swap, offset); error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf)); } return error;} /* * 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(long) - 1) struct swap_map_page { unsigned long entries[MAP_PAGE_ENTRIES]; unsigned long 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; unsigned long cur_swap; struct bitmap_page *bitmap; unsigned int k;}; static void release_swap_writer(struct swap_map_handle *handle){ if (handle->cur) free_page((unsigned long)handle->cur); handle->cur = NULL; if (handle->bitmap) free_bitmap(handle->bitmap); handle->bitmap = NULL;} static int get_swap_writer(struct swap_map_handle *handle){ handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); if (!handle->cur) return -ENOMEM; handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0)); if (!handle->bitmap) { release_swap_writer(handle); return -ENOMEM; } handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap); if (!handle->cur_swap) { release_swap_writer(handle); return -ENOSPC; } handle->k = 0; return 0;} static int swap_write_page(struct swap_map_handle *handle, void *buf){ int error; unsigned long offset; if (!handle->cur) return -EINVAL; offset = alloc_swap_page(root_swap, handle->bitmap); error = write_page(buf, offset); if (error) return error; handle->cur->entries[handle->k++] = offset; if (handle->k >= MAP_PAGE_ENTRIES) { offset = alloc_swap_page(root_swap, handle->bitmap); if (!offset) return -ENOSPC; handle->cur->next_swap = offset; error = write_page(handle->cur, handle->cur_swap); if (error) return error; memset(handle->cur, 0, PAGE_SIZE); handle->cur_swap = offset; handle->k = 0; } return 0;} static int flush_swap_writer(struct swap_map_handle *handle){ if (handle->cur && handle->cur_swap) return write_page(handle->cur, handle->cur_swap); else return -EINVAL;} /** * save_image - save the suspend image data */ static int save_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_pages){ unsigned int m; int ret; int error = 0; printk("Saving image data pages (%u pages) ... ", nr_pages); m = nr_pages / 100; if (!m) m = 1; nr_pages = 0; do { ret = snapshot_read_next(snapshot, PAGE_SIZE); if (ret > 0) { error = swap_write_page(handle, data_of(*snapshot)); if (error) break; if (!(nr_pages % m)) printk("\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } } while (ret > 0); if (!error) printk("\b\b\b\bdone\n"); return error;} /** * enough_swap - Make sure we have enough swap to save the image. * * Returns TRUE or FALSE after checking the total amount of swap * space avaiable from the resume partition. */ static int enough_swap(unsigned int nr_pages){ unsigned int free_swap = count_swap_pages(root_swap, 1); pr_debug("swsusp: free swap pages: %u\n", free_swap); return free_swap > (nr_pages + PAGES_FOR_IO + (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);} /** * swsusp_write - Write entire image and metadata. * * It is important _NOT_ to umount filesystems at this point. We want * them synced (in case something goes wrong) but we DO not want to mark * filesystem clean: it is not. (And it does not matter, if we resume * correctly, we'll mark system clean, anyway.) */ int swsusp_write(void){ struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; unsigned long start; int error; if ((error = swsusp_swap_check())) { printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n"); return error; } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_read_next(&snapshot, PAGE_SIZE); if (error < PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); if (!enough_swap(header->pages)) { printk(KERN_ERR "swsusp: Not enough free swap\n"); return -ENOSPC; } error = get_swap_writer(&handle); if (!error) { start = handle.cur_swap; error = swap_write_page(&handle, header); } if (!error) error = save_image(&handle, &snapshot, header->pages - 1); if (!error) { flush_swap_writer(&handle); printk("S"); error = mark_swapfiles(swp_entry(root_swap, start)); printk("|\n"); } if (error) free_all_swap_pages(root_swap, handle.bitmap); release_swap_writer(&handle); return error;} /* * Using bio to read from swap. * This code requires a bit more work than just using buffer heads * but, it is the recommended way for 2.5/2.6. * The following are to signal the beginning and end of I/O. Bios * finish asynchronously, while we want them to happen synchronously. * A simple atomic_t, and a wait loop take care of this problem. */ static atomic_t io_done = ATOMIC_INIT(0); static int end_io(struct bio *bio, unsigned int num, int err){ if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) panic("I/O error reading memory image"); atomic_set(&io_done, 0); return 0;} 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. * * Straight from the textbook - allocate and initialize the bio. * If we're writing, make sure the page is marked as dirty. * Then submit it and wait. */ static int submit(int rw, pgoff_t page_off, void *page){ int error = 0; struct bio *bio; bio = bio_alloc(GFP_ATOMIC, 1); if (!bio) return -ENOMEM; bio->bi_sector = page_off * (PAGE_SIZE >> 9); bio->bi_bdev = resume_bdev; bio->bi_end_io = end_io; if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) { printk("swsusp: ERROR: adding page to bio at %ld\n",page_off); error = -EFAULT; goto Done; } atomic_set(&io_done, 1); submit_bio(rw | (1 << BIO_RW_SYNC), bio); while (atomic_read(&io_done)) yield(); if (rw == READ) bio_set_pages_dirty(bio); Done: bio_put(bio); return error;} static int bio_read_page(pgoff_t page_off, void *page){ return submit(READ, page_off, page);} static int bio_write_page(pgoff_t page_off, void *page){ return submit(WRITE, page_off, page);} /** * The following functions allow us to read data using a swap map * in a file-alike way */ static void release_swap_reader(struct swap_map_handle *handle){ if (handle->cur) free_page((unsigned long)handle->cur); handle->cur = NULL;} static int get_swap_reader(struct swap_map_handle *handle, swp_entry_t start){ int error; if (!swp_offset(start)) return -EINVAL; handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC); if (!handle->cur) return -ENOMEM; error = bio_read_page(swp_offset(start), handle->cur); if (error) { release_swap_reader(handle); return error; } handle->k = 0; return 0;} static int swap_read_page(struct swap_map_handle *handle, void *buf){ unsigned long offset; int error; if (!handle->cur) return -EINVAL; offset = handle->cur->entries[handle->k]; if (!offset) return -EFAULT; error = bio_read_page(offset, buf); if (error) return error; if (++handle->k >= MAP_PAGE_ENTRIES) { handle->k = 0; offset = handle->cur->next_swap; if (!offset) release_swap_reader(handle); else error = bio_read_page(offset, handle->cur); } return error;} /** * load_image - load the image using the swap map handle * @handle and the snapshot handle @snapshot * (assume there are @nr_pages pages to load) */ static int load_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_pages){ unsigned int m; int ret; int error = 0; printk("Loading image data pages (%u pages) ... ", nr_pages); m = nr_pages / 100; if (!m) m = 1; nr_pages = 0; do { ret = snapshot_write_next(snapshot, PAGE_SIZE); if (ret > 0) { error = swap_read_page(handle, data_of(*snapshot)); if (error) break; if (!(nr_pages % m)) printk("\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } } while (ret > 0); if (!error) { printk("\b\b\b\bdone\n"); if (!snapshot_image_loaded(snapshot)) error = -ENODATA; } return error;} int swsusp_read(void){ int error; struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; if (IS_ERR(resume_bdev)) { pr_debug("swsusp: block device not initialised\n"); return PTR_ERR(resume_bdev); } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_write_next(&snapshot, PAGE_SIZE); if (error < PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); error = get_swap_reader(&handle, swsusp_header.image); if (!error) error = swap_read_page(&handle, header); if (!error) error = load_image(&handle, &snapshot, header->pages - 1); release_swap_reader(&handle); blkdev_put(resume_bdev); if (!error) pr_debug("swsusp: Reading resume file was successful\n"); else pr_debug("swsusp: Error %d resuming\n", error); return error;} /** * swsusp_check - Check for swsusp signature in the resume device */Lines 1–500 of 545. 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/* * linux/kernel/power/swap.c * * This file provides functions for reading the suspend image from * and writing it to a swap partition. * * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> * * This file is released under the GPLv2. * */ #include <linux/module.h> #include <linux/smp_lock.h> #include <linux/file.h> #include <linux/utsname.h> #include <linux/version.h> #include <linux/delay.h> #include <linux/bitops.h> #include <linux/genhd.h> #include <linux/device.h> #include <linux/buffer_head.h> #include <linux/bio.h> #include <linux/swap.h> #include <linux/swapops.h> #include <linux/pm.h> #include "power.h" extern char resume_file[]; #define SWSUSP_SIG "S1SUSPEND" static struct swsusp_header { char reserved[PAGE_SIZE - 20 - sizeof(swp_entry_t)]; swp_entry_t image; char orig_sig[10]; char sig[10]; } __attribute__((packed, aligned(PAGE_SIZE))) swsusp_header; /* * Saving part... */ static unsigned short root_swap = 0xffff; static int mark_swapfiles(swp_entry_t start) { int error; rw_swap_page_sync(READ, swp_entry(root_swap, 0), virt_to_page((unsigned long)&swsusp_header)); 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; error = rw_swap_page_sync(WRITE, swp_entry(root_swap, 0), virt_to_page((unsigned long) &swsusp_header)); } else { pr_debug("swsusp: Partition is not swap space.\n"); error = -ENODEV; } return error; } /** * swsusp_swap_check - check if the resume device is a swap device * and get its index (if so) */ static int swsusp_swap_check(void) /* This is called before saving image */ { int res = swap_type_of(swsusp_resume_device); if (res >= 0) { root_swap = res; return 0; } return res; } /** * write_page - Write one page to given swap location. * @buf: Address we're writing. * @offset: Offset of the swap page we're writing to. */ static int write_page(void *buf, unsigned long offset) { swp_entry_t entry; int error = -ENOSPC; if (offset) { entry = swp_entry(root_swap, offset); error = rw_swap_page_sync(WRITE, entry, virt_to_page(buf)); } return error; } /* * 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(long) - 1) struct swap_map_page { unsigned long entries[MAP_PAGE_ENTRIES]; unsigned long 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; unsigned long cur_swap; struct bitmap_page *bitmap; unsigned int k; }; static void release_swap_writer(struct swap_map_handle *handle) { if (handle->cur) free_page((unsigned long)handle->cur); handle->cur = NULL; if (handle->bitmap) free_bitmap(handle->bitmap); handle->bitmap = NULL; } static int get_swap_writer(struct swap_map_handle *handle) { handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); if (!handle->cur) return -ENOMEM; handle->bitmap = alloc_bitmap(count_swap_pages(root_swap, 0)); if (!handle->bitmap) { release_swap_writer(handle); return -ENOMEM; } handle->cur_swap = alloc_swap_page(root_swap, handle->bitmap); if (!handle->cur_swap) { release_swap_writer(handle); return -ENOSPC; } handle->k = 0; return 0; } static int swap_write_page(struct swap_map_handle *handle, void *buf) { int error; unsigned long offset; if (!handle->cur) return -EINVAL; offset = alloc_swap_page(root_swap, handle->bitmap); error = write_page(buf, offset); if (error) return error; handle->cur->entries[handle->k++] = offset; if (handle->k >= MAP_PAGE_ENTRIES) { offset = alloc_swap_page(root_swap, handle->bitmap); if (!offset) return -ENOSPC; handle->cur->next_swap = offset; error = write_page(handle->cur, handle->cur_swap); if (error) return error; memset(handle->cur, 0, PAGE_SIZE); handle->cur_swap = offset; handle->k = 0; } return 0; } static int flush_swap_writer(struct swap_map_handle *handle) { if (handle->cur && handle->cur_swap) return write_page(handle->cur, handle->cur_swap); else return -EINVAL; } /** * save_image - save the suspend image data */ static int save_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_pages) { unsigned int m; int ret; int error = 0; printk("Saving image data pages (%u pages) ... ", nr_pages); m = nr_pages / 100; if (!m) m = 1; nr_pages = 0; do { ret = snapshot_read_next(snapshot, PAGE_SIZE); if (ret > 0) { error = swap_write_page(handle, data_of(*snapshot)); if (error) break; if (!(nr_pages % m)) printk("\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } } while (ret > 0); if (!error) printk("\b\b\b\bdone\n"); return error; } /** * enough_swap - Make sure we have enough swap to save the image. * * Returns TRUE or FALSE after checking the total amount of swap * space avaiable from the resume partition. */ static int enough_swap(unsigned int nr_pages) { unsigned int free_swap = count_swap_pages(root_swap, 1); pr_debug("swsusp: free swap pages: %u\n", free_swap); return free_swap > (nr_pages + PAGES_FOR_IO + (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE); } /** * swsusp_write - Write entire image and metadata. * * It is important _NOT_ to umount filesystems at this point. We want * them synced (in case something goes wrong) but we DO not want to mark * filesystem clean: it is not. (And it does not matter, if we resume * correctly, we'll mark system clean, anyway.) */ int swsusp_write(void) { struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; unsigned long start; int error; if ((error = swsusp_swap_check())) { printk(KERN_ERR "swsusp: Cannot find swap device, try swapon -a.\n"); return error; } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_read_next(&snapshot, PAGE_SIZE); if (error < PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); if (!enough_swap(header->pages)) { printk(KERN_ERR "swsusp: Not enough free swap\n"); return -ENOSPC; } error = get_swap_writer(&handle); if (!error) { start = handle.cur_swap; error = swap_write_page(&handle, header); } if (!error) error = save_image(&handle, &snapshot, header->pages - 1); if (!error) { flush_swap_writer(&handle); printk("S"); error = mark_swapfiles(swp_entry(root_swap, start)); printk("|\n"); } if (error) free_all_swap_pages(root_swap, handle.bitmap); release_swap_writer(&handle); return error; } /* * Using bio to read from swap. * This code requires a bit more work than just using buffer heads * but, it is the recommended way for 2.5/2.6. * The following are to signal the beginning and end of I/O. Bios * finish asynchronously, while we want them to happen synchronously. * A simple atomic_t, and a wait loop take care of this problem. */ static atomic_t io_done = ATOMIC_INIT(0); static int end_io(struct bio *bio, unsigned int num, int err) { if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) panic("I/O error reading memory image"); atomic_set(&io_done, 0); return 0; } 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. * * Straight from the textbook - allocate and initialize the bio. * If we're writing, make sure the page is marked as dirty. * Then submit it and wait. */ static int submit(int rw, pgoff_t page_off, void *page) { int error = 0; struct bio *bio; bio = bio_alloc(GFP_ATOMIC, 1); if (!bio) return -ENOMEM; bio->bi_sector = page_off * (PAGE_SIZE >> 9); bio->bi_bdev = resume_bdev; bio->bi_end_io = end_io; if (bio_add_page(bio, virt_to_page(page), PAGE_SIZE, 0) < PAGE_SIZE) { printk("swsusp: ERROR: adding page to bio at %ld\n",page_off); error = -EFAULT; goto Done; } atomic_set(&io_done, 1); submit_bio(rw | (1 << BIO_RW_SYNC), bio); while (atomic_read(&io_done)) yield(); if (rw == READ) bio_set_pages_dirty(bio); Done: bio_put(bio); return error; } static int bio_read_page(pgoff_t page_off, void *page) { return submit(READ, page_off, page); } static int bio_write_page(pgoff_t page_off, void *page) { return submit(WRITE, page_off, page); } /** * The following functions allow us to read data using a swap map * in a file-alike way */ static void release_swap_reader(struct swap_map_handle *handle) { if (handle->cur) free_page((unsigned long)handle->cur); handle->cur = NULL; } static int get_swap_reader(struct swap_map_handle *handle, swp_entry_t start) { int error; if (!swp_offset(start)) return -EINVAL; handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_ATOMIC); if (!handle->cur) return -ENOMEM; error = bio_read_page(swp_offset(start), handle->cur); if (error) { release_swap_reader(handle); return error; } handle->k = 0; return 0; } static int swap_read_page(struct swap_map_handle *handle, void *buf) { unsigned long offset; int error; if (!handle->cur) return -EINVAL; offset = handle->cur->entries[handle->k]; if (!offset) return -EFAULT; error = bio_read_page(offset, buf); if (error) return error; if (++handle->k >= MAP_PAGE_ENTRIES) { handle->k = 0; offset = handle->cur->next_swap; if (!offset) release_swap_reader(handle); else error = bio_read_page(offset, handle->cur); } return error; } /** * load_image - load the image using the swap map handle * @handle and the snapshot handle @snapshot * (assume there are @nr_pages pages to load) */ static int load_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_pages) { unsigned int m; int ret; int error = 0; printk("Loading image data pages (%u pages) ... ", nr_pages); m = nr_pages / 100; if (!m) m = 1; nr_pages = 0; do { ret = snapshot_write_next(snapshot, PAGE_SIZE); if (ret > 0) { error = swap_read_page(handle, data_of(*snapshot)); if (error) break; if (!(nr_pages % m)) printk("\b\b\b\b%3d%%", nr_pages / m); nr_pages++; } } while (ret > 0); if (!error) { printk("\b\b\b\bdone\n"); if (!snapshot_image_loaded(snapshot)) error = -ENODATA; } return error; } int swsusp_read(void) { int error; struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; if (IS_ERR(resume_bdev)) { pr_debug("swsusp: block device not initialised\n"); return PTR_ERR(resume_bdev); } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_write_next(&snapshot, PAGE_SIZE); if (error < PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); error = get_swap_reader(&handle, swsusp_header.image); if (!error) error = swap_read_page(&handle, header); if (!error) error = load_image(&handle, &snapshot, header->pages - 1); release_swap_reader(&handle); blkdev_put(resume_bdev); if (!error) pr_debug("swsusp: Reading resume file was successful\n"); else pr_debug("swsusp: Error %d resuming\n", error); return error; } /** * swsusp_check - Check for swsusp signature in the resume device */