diff options
Diffstat (limited to 'kernel/power/swap.c')
| -rw-r--r-- | kernel/power/swap.c | 1619 |
1 files changed, 1619 insertions, 0 deletions
diff --git a/kernel/power/swap.c b/kernel/power/swap.c new file mode 100644 index 000000000..5ab54ab5a --- /dev/null +++ b/kernel/power/swap.c @@ -0,0 +1,1619 @@ +// 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 <pavel@ucw.cz> + * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> + * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com> + */ + +#define pr_fmt(fmt) "PM: " fmt + +#include <linux/module.h> +#include <linux/file.h> +#include <linux/delay.h> +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/swap.h> +#include <linux/swapops.h> +#include <linux/pm.h> +#include <linux/slab.h> +#include <linux/lzo.h> +#include <linux/vmalloc.h> +#include <linux/cpumask.h> +#include <linux/atomic.h> +#include <linux/kthread.h> +#include <linux/crc32.h> +#include <linux/ktime.h> + +#include "power.h" + +#define HIBERNATE_SIG "S1SUSPEND" + +u32 swsusp_hardware_signature; + +/* + * 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) - sizeof(u32)]; + u32 hw_sig; + 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(blk_opf_t opf, 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(hib_resume_bdev, 1, opf, GFP_NOIO | __GFP_HIGH); + bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9); + + 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, 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; + if (swsusp_hardware_signature) { + swsusp_header->hw_sig = swsusp_hardware_signature; + flags |= SF_HW_SIG; + } + 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 = vzalloc(array_size(nr_threads, sizeof(*data))); + if (!data) { + pr_err("Failed to allocate LZO data\n"); + ret = -ENOMEM; + goto out_clean; + } + + crc = kzalloc(sizeof(*crc), GFP_KERNEL); + if (!crc) { + pr_err("Failed to allocate crc\n"); + ret = -ENOMEM; + goto out_clean; + } + + /* + * 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, 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, 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 = vzalloc(array_size(nr_threads, sizeof(*data))); + if (!data) { + pr_err("Failed to allocate LZO data\n"); + ret = -ENOMEM; + goto out_clean; + } + + crc = kzalloc(sizeof(*crc), GFP_KERNEL); + if (!crc) { + pr_err("Failed to allocate crc\n"); + ret = -ENOMEM; + goto out_clean; + } + + 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; + fmode_t mode = FMODE_READ; + + if (snapshot_test) + mode |= FMODE_EXCL; + + hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, + mode, &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, 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; + } + if (!error && swsusp_header->flags & SF_HW_SIG && + swsusp_header->hw_sig != swsusp_hardware_signature) { + pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n", + swsusp_header->hw_sig, swsusp_hardware_signature); + error = -EINVAL; + } + +put: + if (error) + blkdev_put(hib_resume_bdev, mode); + 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, 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); |