// SPDX-License-Identifier: GPL-2.0-only /* * 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 * Copyright (C) 2006 Rafael J. Wysocki * Copyright (C) 2010-2012 Bojan Smojver */ #define pr_fmt(fmt) "PM: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "power.h" #define HIBERNATE_SIG "S1SUSPEND" /* * When reading an {un,}compressed image, we may restore pages in place, * in which case some architectures need these pages cleaning before they * can be executed. We don't know which pages these may be, so clean the lot. */ static bool clean_pages_on_read; static bool clean_pages_on_decompress; /* * 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_ENTRIES 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 pick up all swap_map_page structures into a list. */ #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) /* * Number of free pages that are not high. */ static inline unsigned long low_free_pages(void) { return nr_free_pages() - nr_free_highpages(); } /* * Number of pages required to be kept free while writing the image. Always * half of all available low pages before the writing starts. */ static inline unsigned long reqd_free_pages(void) { return low_free_pages() / 2; } struct swap_map_page { sector_t entries[MAP_PAGE_ENTRIES]; sector_t next_swap; }; struct swap_map_page_list { struct swap_map_page *map; struct swap_map_page_list *next; }; /** * The swap_map_handle structure is used for handling swap in * a file-alike way */ struct swap_map_handle { struct swap_map_page *cur; struct swap_map_page_list *maps; sector_t cur_swap; sector_t first_sector; unsigned int k; unsigned long reqd_free_pages; u32 crc32; }; struct swsusp_header { char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) - sizeof(u32)]; u32 crc32; sector_t image; unsigned int flags; /* Flags to pass to the "boot" kernel */ char orig_sig[10]; char sig[10]; } __packed; static struct swsusp_header *swsusp_header; /** * The following functions are used for tracing the allocated * swap pages, so that they can be freed in case of an error. */ struct swsusp_extent { struct rb_node node; unsigned long start; unsigned long end; }; static struct rb_root swsusp_extents = RB_ROOT; static int swsusp_extents_insert(unsigned long swap_offset) { struct rb_node **new = &(swsusp_extents.rb_node); struct rb_node *parent = NULL; struct swsusp_extent *ext; /* Figure out where to put the new node */ while (*new) { ext = rb_entry(*new, struct swsusp_extent, node); parent = *new; if (swap_offset < ext->start) { /* Try to merge */ if (swap_offset == ext->start - 1) { ext->start--; return 0; } new = &((*new)->rb_left); } else if (swap_offset > ext->end) { /* Try to merge */ if (swap_offset == ext->end + 1) { ext->end++; return 0; } new = &((*new)->rb_right); } else { /* It already is in the tree */ return -EINVAL; } } /* Add the new node and rebalance the tree. */ ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); if (!ext) return -ENOMEM; ext->start = swap_offset; ext->end = swap_offset; rb_link_node(&ext->node, parent, new); rb_insert_color(&ext->node, &swsusp_extents); return 0; } /** * alloc_swapdev_block - allocate a swap page and register that it has * been allocated, so that it can be freed in case of an error. */ sector_t alloc_swapdev_block(int swap) { unsigned long offset; offset = swp_offset(get_swap_page_of_type(swap)); if (offset) { if (swsusp_extents_insert(offset)) swap_free(swp_entry(swap, offset)); else return swapdev_block(swap, offset); } return 0; } /** * free_all_swap_pages - free swap pages allocated for saving image data. * It also frees the extents used to register which swap entries had been * allocated. */ void free_all_swap_pages(int swap) { struct rb_node *node; while ((node = swsusp_extents.rb_node)) { struct swsusp_extent *ext; unsigned long offset; ext = rb_entry(node, struct swsusp_extent, node); rb_erase(node, &swsusp_extents); for (offset = ext->start; offset <= ext->end; offset++) swap_free(swp_entry(swap, offset)); kfree(ext); } } int swsusp_swap_in_use(void) { return (swsusp_extents.rb_node != NULL); } /* * General things */ static unsigned short root_swap = 0xffff; static struct block_device *hib_resume_bdev; struct hib_bio_batch { atomic_t count; wait_queue_head_t wait; blk_status_t error; struct blk_plug plug; }; static void hib_init_batch(struct hib_bio_batch *hb) { atomic_set(&hb->count, 0); init_waitqueue_head(&hb->wait); hb->error = BLK_STS_OK; blk_start_plug(&hb->plug); } static void hib_finish_batch(struct hib_bio_batch *hb) { blk_finish_plug(&hb->plug); } static void hib_end_io(struct bio *bio) { struct hib_bio_batch *hb = bio->bi_private; struct page *page = bio_first_page_all(bio); if (bio->bi_status) { pr_alert("Read-error on swap-device (%u:%u:%Lu)\n", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), (unsigned long long)bio->bi_iter.bi_sector); } if (bio_data_dir(bio) == WRITE) put_page(page); else if (clean_pages_on_read) flush_icache_range((unsigned long)page_address(page), (unsigned long)page_address(page) + PAGE_SIZE); if (bio->bi_status && !hb->error) hb->error = bio->bi_status; if (atomic_dec_and_test(&hb->count)) wake_up(&hb->wait); bio_put(bio); } static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr, struct hib_bio_batch *hb) { struct page *page = virt_to_page(addr); struct bio *bio; int error = 0; bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1); bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9); bio_set_dev(bio, hib_resume_bdev); bio_set_op_attrs(bio, op, op_flags); if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { pr_err("Adding page to bio failed at %llu\n", (unsigned long long)bio->bi_iter.bi_sector); bio_put(bio); return -EFAULT; } if (hb) { bio->bi_end_io = hib_end_io; bio->bi_private = hb; atomic_inc(&hb->count); submit_bio(bio); } else { error = submit_bio_wait(bio); bio_put(bio); } return error; } static int hib_wait_io(struct hib_bio_batch *hb) { /* * We are relying on the behavior of blk_plug that a thread with * a plug will flush the plug list before sleeping. */ wait_event(hb->wait, atomic_read(&hb->count) == 0); return blk_status_to_errno(hb->error); } /* * Saving part */ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) { int error; hib_submit_io(REQ_OP_READ, 0, 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, HIBERNATE_SIG, 10); swsusp_header->image = handle->first_sector; swsusp_header->flags = flags; if (flags & SF_CRC32_MODE) swsusp_header->crc32 = handle->crc32; error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, swsusp_resume_block, swsusp_header, NULL); } else { pr_err("Swap header not found!\n"); error = -ENODEV; } return error; } /** * 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) { int res; if (swsusp_resume_device) res = swap_type_of(swsusp_resume_device, swsusp_resume_block); else res = find_first_swap(&swsusp_resume_device); if (res < 0) return res; root_swap = res; hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE, NULL); if (IS_ERR(hib_resume_bdev)) return PTR_ERR(hib_resume_bdev); res = set_blocksize(hib_resume_bdev, PAGE_SIZE); if (res < 0) blkdev_put(hib_resume_bdev, FMODE_WRITE); 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. * @hb: bio completion batch */ static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb) { void *src; int ret; if (!offset) return -ENOSPC; if (hb) { src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); if (src) { copy_page(src, buf); } else { ret = hib_wait_io(hb); /* Free pages */ if (ret) return ret; src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); if (src) { copy_page(src, buf); } else { WARN_ON_ONCE(1); hb = NULL; /* Go synchronous */ src = buf; } } } else { src = buf; } return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb); } static void release_swap_writer(struct swap_map_handle *handle) { if (handle->cur) free_page((unsigned long)handle->cur); handle->cur = NULL; } static int get_swap_writer(struct swap_map_handle *handle) { int ret; ret = swsusp_swap_check(); if (ret) { if (ret != -ENOSPC) pr_err("Cannot find swap device, try swapon -a\n"); return ret; } handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); if (!handle->cur) { ret = -ENOMEM; goto err_close; } handle->cur_swap = alloc_swapdev_block(root_swap); if (!handle->cur_swap) { ret = -ENOSPC; goto err_rel; } handle->k = 0; handle->reqd_free_pages = reqd_free_pages(); 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, struct hib_bio_batch *hb) { int error = 0; sector_t offset; if (!handle->cur) return -EINVAL; offset = alloc_swapdev_block(root_swap); error = write_page(buf, offset, hb); if (error) return error; handle->cur->entries[handle->k++] = offset; if (handle->k >= MAP_PAGE_ENTRIES) { offset = alloc_swapdev_block(root_swap); if (!offset) return -ENOSPC; handle->cur->next_swap = offset; error = write_page(handle->cur, handle->cur_swap, hb); if (error) goto out; clear_page(handle->cur); handle->cur_swap = offset; handle->k = 0; if (hb && low_free_pages() <= handle->reqd_free_pages) { error = hib_wait_io(hb); if (error) goto out; /* * Recalculate the number of required free pages, to * make sure we never take more than half. */ handle->reqd_free_pages = reqd_free_pages(); } } out: return error; } static int flush_swap_writer(struct swap_map_handle *handle) { if (handle->cur && handle->cur_swap) return write_page(handle->cur, handle->cur_swap, NULL); else return -EINVAL; } static int swap_writer_finish(struct swap_map_handle *handle, unsigned int flags, int error) { if (!error) { pr_info("S"); error = mark_swapfiles(handle, flags); pr_cont("|\n"); flush_swap_writer(handle); } if (error) free_all_swap_pages(root_swap); release_swap_writer(handle); swsusp_close(FMODE_WRITE); return error; } /* We need to remember how much compressed data we need to read. */ #define LZO_HEADER sizeof(size_t) /* Number of pages/bytes we'll compress at one time. */ #define LZO_UNC_PAGES 32 #define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) /* Number of pages/bytes we need for compressed data (worst case). */ #define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ LZO_HEADER, PAGE_SIZE) #define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) /* Maximum number of threads for compression/decompression. */ #define LZO_THREADS 3 /* Minimum/maximum number of pages for read buffering. */ #define LZO_MIN_RD_PAGES 1024 #define LZO_MAX_RD_PAGES 8192 /** * save_image - save the suspend image data */ static int save_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_to_write) { unsigned int m; int ret; int nr_pages; int err2; struct hib_bio_batch hb; ktime_t start; ktime_t stop; hib_init_batch(&hb); pr_info("Saving image data pages (%u pages)...\n", nr_to_write); m = nr_to_write / 10; if (!m) m = 1; nr_pages = 0; start = ktime_get(); while (1) { ret = snapshot_read_next(snapshot); if (ret <= 0) break; ret = swap_write_page(handle, data_of(*snapshot), &hb); if (ret) break; if (!(nr_pages % m)) pr_info("Image saving progress: %3d%%\n", nr_pages / m * 10); nr_pages++; } err2 = hib_wait_io(&hb); hib_finish_batch(&hb); stop = ktime_get(); if (!ret) ret = err2; if (!ret) pr_info("Image saving done\n"); swsusp_show_speed(start, stop, nr_to_write, "Wrote"); return ret; } /** * Structure used for CRC32. */ struct crc_data { struct task_struct *thr; /* thread */ atomic_t ready; /* ready to start flag */ atomic_t stop; /* ready to stop flag */ unsigned run_threads; /* nr current threads */ wait_queue_head_t go; /* start crc update */ wait_queue_head_t done; /* crc update done */ u32 *crc32; /* points to handle's crc32 */ size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */ unsigned char *unc[LZO_THREADS]; /* uncompressed data */ }; /** * CRC32 update function that runs in its own thread. */ static int crc32_threadfn(void *data) { struct crc_data *d = data; unsigned i; while (1) { wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } atomic_set(&d->ready, 0); for (i = 0; i < d->run_threads; i++) *d->crc32 = crc32_le(*d->crc32, d->unc[i], *d->unc_len[i]); atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; } /** * Structure used for LZO data compression. */ struct cmp_data { struct task_struct *thr; /* thread */ atomic_t ready; /* ready to start flag */ atomic_t stop; /* ready to stop flag */ int ret; /* return code */ wait_queue_head_t go; /* start compression */ wait_queue_head_t done; /* compression done */ size_t unc_len; /* uncompressed length */ size_t cmp_len; /* compressed length */ unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */ }; /** * Compression function that runs in its own thread. */ static int lzo_compress_threadfn(void *data) { struct cmp_data *d = data; while (1) { wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; d->ret = -1; atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } atomic_set(&d->ready, 0); d->ret = lzo1x_1_compress(d->unc, d->unc_len, d->cmp + LZO_HEADER, &d->cmp_len, d->wrk); atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; } /** * save_image_lzo - Save the suspend image data compressed with LZO. * @handle: Swap map handle to use for saving the image. * @snapshot: Image to read data from. * @nr_to_write: Number of pages to save. */ static int save_image_lzo(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_to_write) { unsigned int m; int ret = 0; int nr_pages; int err2; struct hib_bio_batch hb; ktime_t start; ktime_t stop; size_t off; unsigned thr, run_threads, nr_threads; unsigned char *page = NULL; struct cmp_data *data = NULL; struct crc_data *crc = NULL; hib_init_batch(&hb); /* * We'll limit the number of threads for compression to limit memory * footprint. */ nr_threads = num_online_cpus() - 1; nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH); if (!page) { pr_err("Failed to allocate LZO page\n"); ret = -ENOMEM; goto out_clean; } data = vmalloc(array_size(nr_threads, sizeof(*data))); if (!data) { pr_err("Failed to allocate LZO data\n"); ret = -ENOMEM; goto out_clean; } for (thr = 0; thr < nr_threads; thr++) memset(&data[thr], 0, offsetof(struct cmp_data, go)); crc = kmalloc(sizeof(*crc), GFP_KERNEL); if (!crc) { pr_err("Failed to allocate crc\n"); ret = -ENOMEM; goto out_clean; } memset(crc, 0, offsetof(struct crc_data, go)); /* * Start the compression threads. */ for (thr = 0; thr < nr_threads; thr++) { init_waitqueue_head(&data[thr].go); init_waitqueue_head(&data[thr].done); data[thr].thr = kthread_run(lzo_compress_threadfn, &data[thr], "image_compress/%u", thr); if (IS_ERR(data[thr].thr)) { data[thr].thr = NULL; pr_err("Cannot start compression threads\n"); ret = -ENOMEM; goto out_clean; } } /* * Start the CRC32 thread. */ init_waitqueue_head(&crc->go); init_waitqueue_head(&crc->done); handle->crc32 = 0; crc->crc32 = &handle->crc32; for (thr = 0; thr < nr_threads; thr++) { crc->unc[thr] = data[thr].unc; crc->unc_len[thr] = &data[thr].unc_len; } crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); if (IS_ERR(crc->thr)) { crc->thr = NULL; pr_err("Cannot start CRC32 thread\n"); ret = -ENOMEM; goto out_clean; } /* * Adjust the number of required free pages after all allocations have * been done. We don't want to run out of pages when writing. */ handle->reqd_free_pages = reqd_free_pages(); pr_info("Using %u thread(s) for compression\n", nr_threads); pr_info("Compressing and saving image data (%u pages)...\n", nr_to_write); m = nr_to_write / 10; if (!m) m = 1; nr_pages = 0; start = ktime_get(); for (;;) { for (thr = 0; thr < nr_threads; thr++) { for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) { ret = snapshot_read_next(snapshot); if (ret < 0) goto out_finish; if (!ret) break; memcpy(data[thr].unc + off, data_of(*snapshot), PAGE_SIZE); if (!(nr_pages % m)) pr_info("Image saving progress: %3d%%\n", nr_pages / m * 10); nr_pages++; } if (!off) break; data[thr].unc_len = off; atomic_set_release(&data[thr].ready, 1); wake_up(&data[thr].go); } if (!thr) break; crc->run_threads = thr; atomic_set_release(&crc->ready, 1); wake_up(&crc->go); for (run_threads = thr, thr = 0; thr < run_threads; thr++) { wait_event(data[thr].done, atomic_read_acquire(&data[thr].stop)); atomic_set(&data[thr].stop, 0); ret = data[thr].ret; if (ret < 0) { pr_err("LZO compression failed\n"); goto out_finish; } if (unlikely(!data[thr].cmp_len || data[thr].cmp_len > lzo1x_worst_compress(data[thr].unc_len))) { pr_err("Invalid LZO compressed length\n"); ret = -1; goto out_finish; } *(size_t *)data[thr].cmp = data[thr].cmp_len; /* * Given we are writing one page at a time to disk, we * copy that much from the buffer, although the last * bit will likely be smaller than full page. This is * OK - we saved the length of the compressed data, so * any garbage at the end will be discarded when we * read it. */ for (off = 0; off < LZO_HEADER + data[thr].cmp_len; off += PAGE_SIZE) { memcpy(page, data[thr].cmp + off, PAGE_SIZE); ret = swap_write_page(handle, page, &hb); if (ret) goto out_finish; } } wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); } out_finish: err2 = hib_wait_io(&hb); stop = ktime_get(); if (!ret) ret = err2; if (!ret) pr_info("Image saving done\n"); swsusp_show_speed(start, stop, nr_to_write, "Wrote"); out_clean: hib_finish_batch(&hb); if (crc) { if (crc->thr) kthread_stop(crc->thr); kfree(crc); } if (data) { for (thr = 0; thr < nr_threads; thr++) if (data[thr].thr) kthread_stop(data[thr].thr); vfree(data); } if (page) free_page((unsigned long)page); return ret; } /** * enough_swap - Make sure we have enough swap to save the image. * * Returns TRUE or FALSE after checking the total amount of swap * space available from the resume partition. */ static int enough_swap(unsigned int nr_pages) { unsigned int free_swap = count_swap_pages(root_swap, 1); unsigned int required; pr_debug("Free swap pages: %u\n", free_swap); required = PAGES_FOR_IO + nr_pages; return free_swap > required; } /** * swsusp_write - Write entire image and metadata. * @flags: flags to pass to the "boot" kernel in the image header * * 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(unsigned int flags) { struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; unsigned long pages; int error; pages = snapshot_get_image_size(); error = get_swap_writer(&handle); if (error) { pr_err("Cannot get swap writer\n"); return error; } if (flags & SF_NOCOMPRESS_MODE) { if (!enough_swap(pages)) { pr_err("Not enough free swap\n"); error = -ENOSPC; goto out_finish; } } memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_read_next(&snapshot); if (error < (int)PAGE_SIZE) { if (error >= 0) error = -EFAULT; goto out_finish; } header = (struct swsusp_info *)data_of(snapshot); error = swap_write_page(&handle, header, NULL); if (!error) { error = (flags & SF_NOCOMPRESS_MODE) ? save_image(&handle, &snapshot, pages - 1) : save_image_lzo(&handle, &snapshot, pages - 1); } out_finish: error = swap_writer_finish(&handle, flags, error); return error; } /** * 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) { struct swap_map_page_list *tmp; while (handle->maps) { if (handle->maps->map) free_page((unsigned long)handle->maps->map); tmp = handle->maps; handle->maps = handle->maps->next; kfree(tmp); } handle->cur = NULL; } static int get_swap_reader(struct swap_map_handle *handle, unsigned int *flags_p) { int error; struct swap_map_page_list *tmp, *last; sector_t offset; *flags_p = swsusp_header->flags; if (!swsusp_header->image) /* how can this happen? */ return -EINVAL; handle->cur = NULL; last = handle->maps = NULL; offset = swsusp_header->image; while (offset) { tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL); if (!tmp) { release_swap_reader(handle); return -ENOMEM; } if (!handle->maps) handle->maps = tmp; if (last) last->next = tmp; last = tmp; tmp->map = (struct swap_map_page *) __get_free_page(GFP_NOIO | __GFP_HIGH); if (!tmp->map) { release_swap_reader(handle); return -ENOMEM; } error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL); if (error) { release_swap_reader(handle); return error; } offset = tmp->map->next_swap; } handle->k = 0; handle->cur = handle->maps->map; return 0; } static int swap_read_page(struct swap_map_handle *handle, void *buf, struct hib_bio_batch *hb) { sector_t offset; int error; struct swap_map_page_list *tmp; if (!handle->cur) return -EINVAL; offset = handle->cur->entries[handle->k]; if (!offset) return -EFAULT; error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb); if (error) return error; if (++handle->k >= MAP_PAGE_ENTRIES) { handle->k = 0; free_page((unsigned long)handle->maps->map); tmp = handle->maps; handle->maps = handle->maps->next; kfree(tmp); if (!handle->maps) release_swap_reader(handle); else handle->cur = handle->maps->map; } 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 * (assume there are @nr_pages pages to load) */ static int load_image(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_to_read) { unsigned int m; int ret = 0; ktime_t start; ktime_t stop; struct hib_bio_batch hb; int err2; unsigned nr_pages; hib_init_batch(&hb); clean_pages_on_read = true; pr_info("Loading image data pages (%u pages)...\n", nr_to_read); m = nr_to_read / 10; if (!m) m = 1; nr_pages = 0; start = ktime_get(); for ( ; ; ) { ret = snapshot_write_next(snapshot); if (ret <= 0) break; ret = swap_read_page(handle, data_of(*snapshot), &hb); if (ret) break; if (snapshot->sync_read) ret = hib_wait_io(&hb); if (ret) break; if (!(nr_pages % m)) pr_info("Image loading progress: %3d%%\n", nr_pages / m * 10); nr_pages++; } err2 = hib_wait_io(&hb); hib_finish_batch(&hb); stop = ktime_get(); if (!ret) ret = err2; if (!ret) { pr_info("Image loading done\n"); snapshot_write_finalize(snapshot); if (!snapshot_image_loaded(snapshot)) ret = -ENODATA; } swsusp_show_speed(start, stop, nr_to_read, "Read"); return ret; } /** * Structure used for LZO data decompression. */ struct dec_data { struct task_struct *thr; /* thread */ atomic_t ready; /* ready to start flag */ atomic_t stop; /* ready to stop flag */ int ret; /* return code */ wait_queue_head_t go; /* start decompression */ wait_queue_head_t done; /* decompression done */ size_t unc_len; /* uncompressed length */ size_t cmp_len; /* compressed length */ unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ }; /** * Decompression function that runs in its own thread. */ static int lzo_decompress_threadfn(void *data) { struct dec_data *d = data; while (1) { wait_event(d->go, atomic_read_acquire(&d->ready) || kthread_should_stop()); if (kthread_should_stop()) { d->thr = NULL; d->ret = -1; atomic_set_release(&d->stop, 1); wake_up(&d->done); break; } atomic_set(&d->ready, 0); d->unc_len = LZO_UNC_SIZE; d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, d->unc, &d->unc_len); if (clean_pages_on_decompress) flush_icache_range((unsigned long)d->unc, (unsigned long)d->unc + d->unc_len); atomic_set_release(&d->stop, 1); wake_up(&d->done); } return 0; } /** * load_image_lzo - Load compressed image data and decompress them with LZO. * @handle: Swap map handle to use for loading data. * @snapshot: Image to copy uncompressed data into. * @nr_to_read: Number of pages to load. */ static int load_image_lzo(struct swap_map_handle *handle, struct snapshot_handle *snapshot, unsigned int nr_to_read) { unsigned int m; int ret = 0; int eof = 0; struct hib_bio_batch hb; ktime_t start; ktime_t stop; unsigned nr_pages; size_t off; unsigned i, thr, run_threads, nr_threads; unsigned ring = 0, pg = 0, ring_size = 0, have = 0, want, need, asked = 0; unsigned long read_pages = 0; unsigned char **page = NULL; struct dec_data *data = NULL; struct crc_data *crc = NULL; hib_init_batch(&hb); /* * We'll limit the number of threads for decompression to limit memory * footprint. */ nr_threads = num_online_cpus() - 1; nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page))); if (!page) { pr_err("Failed to allocate LZO page\n"); ret = -ENOMEM; goto out_clean; } data = vmalloc(array_size(nr_threads, sizeof(*data))); if (!data) { pr_err("Failed to allocate LZO data\n"); ret = -ENOMEM; goto out_clean; } for (thr = 0; thr < nr_threads; thr++) memset(&data[thr], 0, offsetof(struct dec_data, go)); crc = kmalloc(sizeof(*crc), GFP_KERNEL); if (!crc) { pr_err("Failed to allocate crc\n"); ret = -ENOMEM; goto out_clean; } memset(crc, 0, offsetof(struct crc_data, go)); clean_pages_on_decompress = true; /* * Start the decompression threads. */ for (thr = 0; thr < nr_threads; thr++) { init_waitqueue_head(&data[thr].go); init_waitqueue_head(&data[thr].done); data[thr].thr = kthread_run(lzo_decompress_threadfn, &data[thr], "image_decompress/%u", thr); if (IS_ERR(data[thr].thr)) { data[thr].thr = NULL; pr_err("Cannot start decompression threads\n"); ret = -ENOMEM; goto out_clean; } } /* * Start the CRC32 thread. */ init_waitqueue_head(&crc->go); init_waitqueue_head(&crc->done); handle->crc32 = 0; crc->crc32 = &handle->crc32; for (thr = 0; thr < nr_threads; thr++) { crc->unc[thr] = data[thr].unc; crc->unc_len[thr] = &data[thr].unc_len; } crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); if (IS_ERR(crc->thr)) { crc->thr = NULL; pr_err("Cannot start CRC32 thread\n"); ret = -ENOMEM; goto out_clean; } /* * Set the number of pages for read buffering. * This is complete guesswork, because we'll only know the real * picture once prepare_image() is called, which is much later on * during the image load phase. We'll assume the worst case and * say that none of the image pages are from high memory. */ if (low_free_pages() > snapshot_get_image_size()) read_pages = (low_free_pages() - snapshot_get_image_size()) / 2; read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES); for (i = 0; i < read_pages; i++) { page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ? GFP_NOIO | __GFP_HIGH : GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); if (!page[i]) { if (i < LZO_CMP_PAGES) { ring_size = i; pr_err("Failed to allocate LZO pages\n"); ret = -ENOMEM; goto out_clean; } else { break; } } } want = ring_size = i; pr_info("Using %u thread(s) for decompression\n", nr_threads); pr_info("Loading and decompressing image data (%u pages)...\n", nr_to_read); m = nr_to_read / 10; if (!m) m = 1; nr_pages = 0; start = ktime_get(); ret = snapshot_write_next(snapshot); if (ret <= 0) goto out_finish; for(;;) { for (i = 0; !eof && i < want; i++) { ret = swap_read_page(handle, page[ring], &hb); if (ret) { /* * On real read error, finish. On end of data, * set EOF flag and just exit the read loop. */ if (handle->cur && handle->cur->entries[handle->k]) { goto out_finish; } else { eof = 1; break; } } if (++ring >= ring_size) ring = 0; } asked += i; want -= i; /* * We are out of data, wait for some more. */ if (!have) { if (!asked) break; ret = hib_wait_io(&hb); if (ret) goto out_finish; have += asked; asked = 0; if (eof) eof = 2; } if (crc->run_threads) { wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); crc->run_threads = 0; } for (thr = 0; have && thr < nr_threads; thr++) { data[thr].cmp_len = *(size_t *)page[pg]; if (unlikely(!data[thr].cmp_len || data[thr].cmp_len > lzo1x_worst_compress(LZO_UNC_SIZE))) { pr_err("Invalid LZO compressed length\n"); ret = -1; goto out_finish; } need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, PAGE_SIZE); if (need > have) { if (eof > 1) { ret = -1; goto out_finish; } break; } for (off = 0; off < LZO_HEADER + data[thr].cmp_len; off += PAGE_SIZE) { memcpy(data[thr].cmp + off, page[pg], PAGE_SIZE); have--; want++; if (++pg >= ring_size) pg = 0; } atomic_set_release(&data[thr].ready, 1); wake_up(&data[thr].go); } /* * Wait for more data while we are decompressing. */ if (have < LZO_CMP_PAGES && asked) { ret = hib_wait_io(&hb); if (ret) goto out_finish; have += asked; asked = 0; if (eof) eof = 2; } for (run_threads = thr, thr = 0; thr < run_threads; thr++) { wait_event(data[thr].done, atomic_read_acquire(&data[thr].stop)); atomic_set(&data[thr].stop, 0); ret = data[thr].ret; if (ret < 0) { pr_err("LZO decompression failed\n"); goto out_finish; } if (unlikely(!data[thr].unc_len || data[thr].unc_len > LZO_UNC_SIZE || data[thr].unc_len & (PAGE_SIZE - 1))) { pr_err("Invalid LZO uncompressed length\n"); ret = -1; goto out_finish; } for (off = 0; off < data[thr].unc_len; off += PAGE_SIZE) { memcpy(data_of(*snapshot), data[thr].unc + off, PAGE_SIZE); if (!(nr_pages % m)) pr_info("Image loading progress: %3d%%\n", nr_pages / m * 10); nr_pages++; ret = snapshot_write_next(snapshot); if (ret <= 0) { crc->run_threads = thr + 1; atomic_set_release(&crc->ready, 1); wake_up(&crc->go); goto out_finish; } } } crc->run_threads = thr; atomic_set_release(&crc->ready, 1); wake_up(&crc->go); } out_finish: if (crc->run_threads) { wait_event(crc->done, atomic_read_acquire(&crc->stop)); atomic_set(&crc->stop, 0); } stop = ktime_get(); if (!ret) { pr_info("Image loading done\n"); snapshot_write_finalize(snapshot); if (!snapshot_image_loaded(snapshot)) ret = -ENODATA; if (!ret) { if (swsusp_header->flags & SF_CRC32_MODE) { if(handle->crc32 != swsusp_header->crc32) { pr_err("Invalid image CRC32!\n"); ret = -ENODATA; } } } } swsusp_show_speed(start, stop, nr_to_read, "Read"); out_clean: hib_finish_batch(&hb); for (i = 0; i < ring_size; i++) free_page((unsigned long)page[i]); if (crc) { if (crc->thr) kthread_stop(crc->thr); kfree(crc); } if (data) { for (thr = 0; thr < nr_threads; thr++) if (data[thr].thr) kthread_stop(data[thr].thr); vfree(data); } vfree(page); return ret; } /** * swsusp_read - read the hibernation image. * @flags_p: flags passed by the "frozen" kernel in the image header should * be written into this memory location */ int swsusp_read(unsigned int *flags_p) { int error; struct swap_map_handle handle; struct snapshot_handle snapshot; struct swsusp_info *header; memset(&snapshot, 0, sizeof(struct snapshot_handle)); error = snapshot_write_next(&snapshot); if (error < (int)PAGE_SIZE) return error < 0 ? error : -EFAULT; header = (struct swsusp_info *)data_of(snapshot); error = get_swap_reader(&handle, flags_p); if (error) goto end; if (!error) error = swap_read_page(&handle, header, NULL); if (!error) { error = (*flags_p & SF_NOCOMPRESS_MODE) ? load_image(&handle, &snapshot, header->pages - 1) : load_image_lzo(&handle, &snapshot, header->pages - 1); } swap_reader_finish(&handle); end: if (!error) pr_debug("Image successfully loaded\n"); else pr_debug("Error %d resuming\n", error); return error; } /** * swsusp_check - Check for swsusp signature in the resume device */ int swsusp_check(void) { int error; void *holder; hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_READ | FMODE_EXCL, &holder); if (!IS_ERR(hib_resume_bdev)) { set_blocksize(hib_resume_bdev, PAGE_SIZE); clear_page(swsusp_header); error = hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block, swsusp_header, NULL); if (error) goto put; if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); /* Reset swap signature now */ error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, swsusp_resume_block, swsusp_header, NULL); } else { error = -EINVAL; } put: if (error) blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL); else pr_debug("Image signature found, resuming\n"); } else { error = PTR_ERR(hib_resume_bdev); } if (error) pr_debug("Image not found (code %d)\n", error); return error; } /** * swsusp_close - close swap device. */ void swsusp_close(fmode_t mode) { if (IS_ERR(hib_resume_bdev)) { pr_debug("Image device not initialised\n"); return; } blkdev_put(hib_resume_bdev, mode); } /** * swsusp_unmark - Unmark swsusp signature in the resume device */ #ifdef CONFIG_SUSPEND int swsusp_unmark(void) { int error; hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block, swsusp_header, NULL); if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) { memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10); error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, swsusp_resume_block, swsusp_header, NULL); } else { pr_err("Cannot find swsusp signature!\n"); error = -ENODEV; } /* * We just returned from suspend, we don't need the image any more. */ free_all_swap_pages(root_swap); return error; } #endif static int __init swsusp_header_init(void) { swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); if (!swsusp_header) panic("Could not allocate memory for swsusp_header\n"); return 0; } core_initcall(swsusp_header_init);