diff options
Diffstat (limited to 'kernel/power/tuxonice_bio_chains.c')
| -rw-r--r-- | kernel/power/tuxonice_bio_chains.c | 1126 |
1 files changed, 1126 insertions, 0 deletions
diff --git a/kernel/power/tuxonice_bio_chains.c b/kernel/power/tuxonice_bio_chains.c new file mode 100644 index 000000000..086a5527d --- /dev/null +++ b/kernel/power/tuxonice_bio_chains.c @@ -0,0 +1,1126 @@ +/* + * kernel/power/tuxonice_bio_devinfo.c + * + * Copyright (C) 2009-2015 Nigel Cunningham (nigel at nigelcunningham com au) + * + * Distributed under GPLv2. + * + */ + +#include <linux/mm_types.h> +#include "tuxonice_bio.h" +#include "tuxonice_bio_internal.h" +#include "tuxonice_alloc.h" +#include "tuxonice_ui.h" +#include "tuxonice.h" +#include "tuxonice_io.h" + +static struct toi_bdev_info *prio_chain_head; +static int num_chains; + +/* Pointer to current entry being loaded/saved. */ +struct toi_extent_iterate_state toi_writer_posn; + +#define metadata_size (sizeof(struct toi_bdev_info) - \ + offsetof(struct toi_bdev_info, uuid)) + +/* + * After section 0 (header) comes 2 => next_section[0] = 2 + */ +static int next_section[3] = { 2, 3, 1 }; + +/** + * dump_block_chains - print the contents of the bdev info array. + **/ +void dump_block_chains(void) +{ + int i = 0; + int j; + struct toi_bdev_info *cur_chain = prio_chain_head; + + while (cur_chain) { + struct hibernate_extent *this = cur_chain->blocks.first; + + printk(KERN_DEBUG "Chain %d (prio %d):", i, cur_chain->prio); + + while (this) { + printk(KERN_CONT " [%lu-%lu]%s", this->start, + this->end, this->next ? "," : ""); + this = this->next; + } + + printk("\n"); + cur_chain = cur_chain->next; + i++; + } + + printk(KERN_DEBUG "Saved states:\n"); + for (i = 0; i < 4; i++) { + printk(KERN_DEBUG "Slot %d: Chain %d.\n", + i, toi_writer_posn.saved_chain_number[i]); + + cur_chain = prio_chain_head; + j = 0; + while (cur_chain) { + printk(KERN_DEBUG " Chain %d: Extent %d. Offset %lu.\n", + j, cur_chain->saved_state[i].extent_num, + cur_chain->saved_state[i].offset); + cur_chain = cur_chain->next; + j++; + } + printk(KERN_CONT "\n"); + } +} + +/** + * + **/ +static void toi_extent_chain_next(void) +{ + struct toi_bdev_info *this = toi_writer_posn.current_chain; + + if (!this->blocks.current_extent) + return; + + if (this->blocks.current_offset == this->blocks.current_extent->end) { + if (this->blocks.current_extent->next) { + this->blocks.current_extent = + this->blocks.current_extent->next; + this->blocks.current_offset = + this->blocks.current_extent->start; + } else { + this->blocks.current_extent = NULL; + this->blocks.current_offset = 0; + } + } else + this->blocks.current_offset++; +} + +/** + * + */ + +static struct toi_bdev_info *__find_next_chain_same_prio(void) +{ + struct toi_bdev_info *start_chain = toi_writer_posn.current_chain; + struct toi_bdev_info *this = start_chain; + int orig_prio = this->prio; + + do { + this = this->next; + + if (!this) + this = prio_chain_head; + + /* Back on original chain? Use it again. */ + if (this == start_chain) + return start_chain; + + } while (!this->blocks.current_extent || this->prio != orig_prio); + + return this; +} + +static void find_next_chain(void) +{ + struct toi_bdev_info *this; + + this = __find_next_chain_same_prio(); + + /* + * If we didn't get another chain of the same priority that we + * can use, look for the next priority. + */ + while (this && !this->blocks.current_extent) + this = this->next; + + toi_writer_posn.current_chain = this; +} + +/** + * toi_extent_state_next - go to the next extent + * @blocks: The number of values to progress. + * @stripe_mode: Whether to spread usage across all chains. + * + * Given a state, progress to the next valid entry. We may begin in an + * invalid state, as we do when invoked after extent_state_goto_start below. + * + * When using compression and expected_compression > 0, we let the image size + * be larger than storage, so we can validly run out of data to return. + **/ +static unsigned long toi_extent_state_next(int blocks, int current_stream) +{ + int i; + + if (!toi_writer_posn.current_chain) + return -ENOSPC; + + /* Assume chains always have lengths that are multiples of @blocks */ + for (i = 0; i < blocks; i++) + toi_extent_chain_next(); + + /* The header stream is not striped */ + if (current_stream || + !toi_writer_posn.current_chain->blocks.current_extent) + find_next_chain(); + + return toi_writer_posn.current_chain ? 0 : -ENOSPC; +} + +static void toi_insert_chain_in_prio_list(struct toi_bdev_info *this) +{ + struct toi_bdev_info **prev_ptr; + struct toi_bdev_info *cur; + + /* Loop through the existing chain, finding where to insert it */ + prev_ptr = &prio_chain_head; + cur = prio_chain_head; + + while (cur && cur->prio >= this->prio) { + prev_ptr = &cur->next; + cur = cur->next; + } + + this->next = *prev_ptr; + *prev_ptr = this; + + this = prio_chain_head; + while (this) + this = this->next; + num_chains++; +} + +/** + * toi_extent_state_goto_start - reinitialize an extent chain iterator + * @state: Iterator to reinitialize + **/ +void toi_extent_state_goto_start(void) +{ + struct toi_bdev_info *this = prio_chain_head; + + while (this) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Setting current extent to %p.", this->blocks.first); + this->blocks.current_extent = this->blocks.first; + if (this->blocks.current_extent) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Setting current offset to %lu.", + this->blocks.current_extent->start); + this->blocks.current_offset = + this->blocks.current_extent->start; + } + + this = this->next; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Setting current chain to %p.", + prio_chain_head); + toi_writer_posn.current_chain = prio_chain_head; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Leaving extent state goto start."); +} + +/** + * toi_extent_state_save - save state of the iterator + * @state: Current state of the chain + * @saved_state: Iterator to populate + * + * Given a state and a struct hibernate_extent_state_store, save the current + * position in a format that can be used with relocated chains (at + * resume time). + **/ +void toi_extent_state_save(int slot) +{ + struct toi_bdev_info *cur_chain = prio_chain_head; + struct hibernate_extent *extent; + struct hibernate_extent_saved_state *chain_state; + int i = 0; + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "toi_extent_state_save, slot %d.", + slot); + + if (!toi_writer_posn.current_chain) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, "No current chain => " + "chain_num = -1."); + toi_writer_posn.saved_chain_number[slot] = -1; + return; + } + + while (cur_chain) { + i++; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Saving chain %d (%p) " + "state, slot %d.", i, cur_chain, slot); + + chain_state = &cur_chain->saved_state[slot]; + + chain_state->offset = cur_chain->blocks.current_offset; + + if (toi_writer_posn.current_chain == cur_chain) { + toi_writer_posn.saved_chain_number[slot] = i; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "This is the chain " + "we were on => chain_num is %d.", i); + } + + if (!cur_chain->blocks.current_extent) { + chain_state->extent_num = 0; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "No current extent " + "for this chain => extent_num %d is 0.", + i); + cur_chain = cur_chain->next; + continue; + } + + extent = cur_chain->blocks.first; + chain_state->extent_num = 1; + + while (extent != cur_chain->blocks.current_extent) { + chain_state->extent_num++; + extent = extent->next; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "extent num %d is %d.", i, + chain_state->extent_num); + + cur_chain = cur_chain->next; + } + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Completed saving extent state slot %d.", slot); +} + +/** + * toi_extent_state_restore - restore the position saved by extent_state_save + * @state: State to populate + * @saved_state: Iterator saved to restore + **/ +void toi_extent_state_restore(int slot) +{ + int i = 0; + struct toi_bdev_info *cur_chain = prio_chain_head; + struct hibernate_extent_saved_state *chain_state; + + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "toi_extent_state_restore - slot %d.", slot); + + if (toi_writer_posn.saved_chain_number[slot] == -1) { + toi_writer_posn.current_chain = NULL; + return; + } + + while (cur_chain) { + int posn; + int j; + i++; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Restoring chain %d (%p) " + "state, slot %d.", i, cur_chain, slot); + + chain_state = &cur_chain->saved_state[slot]; + + posn = chain_state->extent_num; + + cur_chain->blocks.current_extent = cur_chain->blocks.first; + cur_chain->blocks.current_offset = chain_state->offset; + + if (i == toi_writer_posn.saved_chain_number[slot]) { + toi_writer_posn.current_chain = cur_chain; + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Found current chain."); + } + + for (j = 0; j < 4; j++) + if (i == toi_writer_posn.saved_chain_number[j]) { + toi_writer_posn.saved_chain_ptr[j] = cur_chain; + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Found saved chain ptr %d (%p) (offset" + " %d).", j, cur_chain, + cur_chain->saved_state[j].offset); + } + + if (posn) { + while (--posn) + cur_chain->blocks.current_extent = + cur_chain->blocks.current_extent->next; + } else + cur_chain->blocks.current_extent = NULL; + + cur_chain = cur_chain->next; + } + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Done."); + if (test_action_state(TOI_LOGALL)) + dump_block_chains(); +} + +/* + * Storage needed + * + * Returns amount of space in the image header required + * for the chain data. This ignores the links between + * pages, which we factor in when allocating the space. + */ +int toi_bio_devinfo_storage_needed(void) +{ + int result = sizeof(num_chains); + struct toi_bdev_info *chain = prio_chain_head; + + while (chain) { + result += metadata_size; + + /* Chain size */ + result += sizeof(int); + + /* Extents */ + result += (2 * sizeof(unsigned long) * + chain->blocks.num_extents); + + chain = chain->next; + } + + result += 4 * sizeof(int); + return result; +} + +static unsigned long chain_pages_used(struct toi_bdev_info *chain) +{ + struct hibernate_extent *this = chain->blocks.first; + struct hibernate_extent_saved_state *state = &chain->saved_state[3]; + unsigned long size = 0; + int extent_idx = 1; + + if (!state->extent_num) { + if (!this) + return 0; + else + return chain->blocks.size; + } + + while (extent_idx < state->extent_num) { + size += (this->end - this->start + 1); + this = this->next; + extent_idx++; + } + + /* We didn't use the one we're sitting on, so don't count it */ + return size + state->offset - this->start; +} + +void toi_bio_free_unused_storage_chain(struct toi_bdev_info *chain) +{ + unsigned long used = chain_pages_used(chain); + + /* Free the storage */ + unsigned long first_freed = 0; + + if (chain->allocator->bio_allocator_ops->free_unused_storage) + first_freed = chain->allocator->bio_allocator_ops->free_unused_storage(chain, used); + + printk(KERN_EMERG "Used %ld blocks in this chain. First extent freed is %lx.\n", used, first_freed); + + /* Adjust / free the extents. */ + toi_put_extent_chain_from(&chain->blocks, first_freed); + + { + struct hibernate_extent *this = chain->blocks.first; + while (this) { + printk("Extent %lx-%lx.\n", this->start, this->end); + this = this->next; + } + } +} + +/** + * toi_serialise_extent_chain - write a chain in the image + * @chain: Chain to write. + **/ +static int toi_serialise_extent_chain(struct toi_bdev_info *chain) +{ + struct hibernate_extent *this; + int ret; + int i = 1; + + chain->pages_used = chain_pages_used(chain); + + if (test_action_state(TOI_LOGALL)) + dump_block_chains(); + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Serialising chain (dev_t %lx).", + chain->dev_t); + /* Device info - dev_t, prio, bmap_shift, blocks per page, positions */ + ret = toiActiveAllocator->rw_header_chunk(WRITE, &toi_blockwriter_ops, + (char *) &chain->uuid, metadata_size); + if (ret) + return ret; + + /* Num extents */ + ret = toiActiveAllocator->rw_header_chunk(WRITE, &toi_blockwriter_ops, + (char *) &chain->blocks.num_extents, sizeof(int)); + if (ret) + return ret; + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "%d extents.", + chain->blocks.num_extents); + + this = chain->blocks.first; + while (this) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Extent %d.", i); + ret = toiActiveAllocator->rw_header_chunk(WRITE, + &toi_blockwriter_ops, + (char *) this, 2 * sizeof(this->start)); + if (ret) + return ret; + this = this->next; + i++; + } + + return ret; +} + +int toi_serialise_extent_chains(void) +{ + struct toi_bdev_info *this = prio_chain_head; + int result; + + /* Write the number of chains */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Write number of chains (%d)", + num_chains); + result = toiActiveAllocator->rw_header_chunk(WRITE, + &toi_blockwriter_ops, (char *) &num_chains, + sizeof(int)); + if (result) + return result; + + /* Then the chains themselves */ + while (this) { + result = toi_serialise_extent_chain(this); + if (result) + return result; + this = this->next; + } + + /* + * Finally, the chain we should be on at the start of each + * section. + */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Saved chain numbers."); + result = toiActiveAllocator->rw_header_chunk(WRITE, + &toi_blockwriter_ops, + (char *) &toi_writer_posn.saved_chain_number[0], + 4 * sizeof(int)); + + return result; +} + +int toi_register_storage_chain(struct toi_bdev_info *new) +{ + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Inserting chain %p into list.", + new); + toi_insert_chain_in_prio_list(new); + return 0; +} + +static void free_bdev_info(struct toi_bdev_info *chain) +{ + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Free chain %p.", chain); + + toi_message(TOI_BIO, TOI_VERBOSE, 0, " - Block extents."); + toi_put_extent_chain(&chain->blocks); + + /* + * The allocator may need to do more than just free the chains + * (swap_free, for example). Don't call from boot kernel. + */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, " - Allocator extents."); + if (chain->allocator) + chain->allocator->bio_allocator_ops->free_storage(chain); + + /* + * Dropping out of reading atomic copy? Need to undo + * toi_open_by_devnum. + */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, " - Bdev."); + if (chain->bdev && !IS_ERR(chain->bdev) && + chain->bdev != resume_block_device && + chain->bdev != header_block_device && + test_toi_state(TOI_TRYING_TO_RESUME)) + toi_close_bdev(chain->bdev); + + /* Poison */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, " - Struct."); + toi_kfree(39, chain, sizeof(*chain)); + + if (prio_chain_head == chain) + prio_chain_head = NULL; + + num_chains--; +} + +void free_all_bdev_info(void) +{ + struct toi_bdev_info *this = prio_chain_head; + + while (this) { + struct toi_bdev_info *next = this->next; + free_bdev_info(this); + this = next; + } + + memset((char *) &toi_writer_posn, 0, sizeof(toi_writer_posn)); + prio_chain_head = NULL; +} + +static void set_up_start_position(void) +{ + toi_writer_posn.current_chain = prio_chain_head; + go_next_page(0, 0); +} + +/** + * toi_load_extent_chain - read back a chain saved in the image + * @chain: Chain to load + * + * The linked list of extents is reconstructed from the disk. chain will point + * to the first entry. + **/ +int toi_load_extent_chain(int index, int *num_loaded) +{ + struct toi_bdev_info *chain = toi_kzalloc(39, + sizeof(struct toi_bdev_info), GFP_ATOMIC); + struct hibernate_extent *this, *last = NULL; + int i, ret; + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Loading extent chain %d.", index); + /* Get dev_t, prio, bmap_shift, blocks per page, positions */ + ret = toiActiveAllocator->rw_header_chunk_noreadahead(READ, NULL, + (char *) &chain->uuid, metadata_size); + + if (ret) { + printk(KERN_ERR "Failed to read the size of extent chain.\n"); + toi_kfree(39, chain, sizeof(*chain)); + return 1; + } + + toi_bkd.pages_used[index] = chain->pages_used; + + ret = toiActiveAllocator->rw_header_chunk_noreadahead(READ, NULL, + (char *) &chain->blocks.num_extents, sizeof(int)); + if (ret) { + printk(KERN_ERR "Failed to read the size of extent chain.\n"); + toi_kfree(39, chain, sizeof(*chain)); + return 1; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "%d extents.", + chain->blocks.num_extents); + + for (i = 0; i < chain->blocks.num_extents; i++) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Extent %d.", i + 1); + + this = toi_kzalloc(2, sizeof(struct hibernate_extent), + TOI_ATOMIC_GFP); + if (!this) { + printk(KERN_INFO "Failed to allocate a new extent.\n"); + free_bdev_info(chain); + return -ENOMEM; + } + this->next = NULL; + /* Get the next page */ + ret = toiActiveAllocator->rw_header_chunk_noreadahead(READ, + NULL, (char *) this, 2 * sizeof(this->start)); + if (ret) { + printk(KERN_INFO "Failed to read an extent.\n"); + toi_kfree(2, this, sizeof(struct hibernate_extent)); + free_bdev_info(chain); + return 1; + } + + if (last) + last->next = this; + else { + char b1[32], b2[32], b3[32]; + /* + * Open the bdev + */ + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Chain dev_t is %s. Resume dev t is %s. Header" + " bdev_t is %s.\n", + format_dev_t(b1, chain->dev_t), + format_dev_t(b2, resume_dev_t), + format_dev_t(b3, toi_sig_data->header_dev_t)); + + if (chain->dev_t == resume_dev_t) + chain->bdev = resume_block_device; + else if (chain->dev_t == toi_sig_data->header_dev_t) + chain->bdev = header_block_device; + else { + chain->bdev = toi_open_bdev(chain->uuid, + chain->dev_t, 1); + if (IS_ERR(chain->bdev)) { + free_bdev_info(chain); + return -ENODEV; + } + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Chain bmap shift " + "is %d and blocks per page is %d.", + chain->bmap_shift, + chain->blocks_per_page); + + chain->blocks.first = this; + + /* + * Couldn't do this earlier, but can't do + * goto_start now - we may have already used blocks + * in the first chain. + */ + chain->blocks.current_extent = this; + chain->blocks.current_offset = this->start; + + /* + * Can't wait until we've read the whole chain + * before we insert it in the list. We might need + * this chain to read the next page in the header + */ + toi_insert_chain_in_prio_list(chain); + } + + /* + * We have to wait until 2 extents are loaded before setting up + * properly because if the first extent has only one page, we + * will need to put the position on the second extent. Sounds + * obvious, but it wasn't! + */ + (*num_loaded)++; + if ((*num_loaded) == 2) + set_up_start_position(); + last = this; + } + + /* + * Shouldn't get empty chains, but it's not impossible. Link them in so + * they get freed properly later. + */ + if (!chain->blocks.num_extents) + toi_insert_chain_in_prio_list(chain); + + if (!chain->blocks.current_extent) { + chain->blocks.current_extent = chain->blocks.first; + if (chain->blocks.current_extent) + chain->blocks.current_offset = + chain->blocks.current_extent->start; + } + return 0; +} + +int toi_load_extent_chains(void) +{ + int result; + int to_load; + int i; + int extents_loaded = 0; + + result = toiActiveAllocator->rw_header_chunk_noreadahead(READ, NULL, + (char *) &to_load, + sizeof(int)); + if (result) + return result; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "%d chains to read.", to_load); + + for (i = 0; i < to_load; i++) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, " >> Loading chain %d/%d.", + i, to_load); + result = toi_load_extent_chain(i, &extents_loaded); + if (result) + return result; + } + + /* If we never got to a second extent, we still need to do this. */ + if (extents_loaded == 1) + set_up_start_position(); + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Save chain numbers."); + result = toiActiveAllocator->rw_header_chunk_noreadahead(READ, + &toi_blockwriter_ops, + (char *) &toi_writer_posn.saved_chain_number[0], + 4 * sizeof(int)); + + return result; +} + +static int toi_end_of_stream(int writing, int section_barrier) +{ + struct toi_bdev_info *cur_chain = toi_writer_posn.current_chain; + int compare_to = next_section[current_stream]; + struct toi_bdev_info *compare_chain = + toi_writer_posn.saved_chain_ptr[compare_to]; + int compare_offset = compare_chain ? + compare_chain->saved_state[compare_to].offset : 0; + + if (!section_barrier) + return 0; + + if (!cur_chain) + return 1; + + if (cur_chain == compare_chain && + cur_chain->blocks.current_offset == compare_offset) { + if (writing) { + if (!current_stream) { + debug_broken_header(); + return 1; + } + } else { + more_readahead = 0; + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Reached the end of stream %d " + "(not an error).", current_stream); + return 1; + } + } + + return 0; +} + +/** + * go_next_page - skip blocks to the start of the next page + * @writing: Whether we're reading or writing the image. + * + * Go forward one page. + **/ +int go_next_page(int writing, int section_barrier) +{ + struct toi_bdev_info *cur_chain = toi_writer_posn.current_chain; + int max = cur_chain ? cur_chain->blocks_per_page : 1; + + /* Nope. Go foward a page - or maybe two. Don't stripe the header, + * so that bad fragmentation doesn't put the extent data containing + * the location of the second page out of the first header page. + */ + if (toi_extent_state_next(max, current_stream)) { + /* Don't complain if readahead falls off the end */ + if (writing && section_barrier) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Extent state eof. " + "Expected compression ratio too optimistic?"); + if (test_action_state(TOI_LOGALL)) + dump_block_chains(); + } + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Ran out of extents to " + "read/write. (Not necessarily a fatal error."); + return -ENOSPC; + } + + return 0; +} + +int devices_of_same_priority(struct toi_bdev_info *this) +{ + struct toi_bdev_info *check = prio_chain_head; + int i = 0; + + while (check) { + if (check->prio == this->prio) + i++; + check = check->next; + } + + return i; +} + +/** + * toi_bio_rw_page - do i/o on the next disk page in the image + * @writing: Whether reading or writing. + * @page: Page to do i/o on. + * @is_readahead: Whether we're doing readahead + * @free_group: The group used in allocating the page + * + * Submit a page for reading or writing, possibly readahead. + * Pass the group used in allocating the page as well, as it should + * be freed on completion of the bio if we're writing the page. + **/ +int toi_bio_rw_page(int writing, struct page *page, + int is_readahead, int free_group) +{ + int result = toi_end_of_stream(writing, 1); + struct toi_bdev_info *dev_info = toi_writer_posn.current_chain; + + if (result) { + if (writing) + abort_hibernate(TOI_INSUFFICIENT_STORAGE, + "Insufficient storage for your image."); + else + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Seeking to " + "read/write another page when stream has " + "ended."); + return -ENOSPC; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "%s %lx:%ld", + writing ? "Write" : "Read", + dev_info->dev_t, dev_info->blocks.current_offset); + + result = toi_do_io(writing, dev_info->bdev, + dev_info->blocks.current_offset << dev_info->bmap_shift, + page, is_readahead, 0, free_group); + + /* Ignore the result here - will check end of stream if come in again */ + go_next_page(writing, 1); + + if (result) + printk(KERN_ERR "toi_do_io returned %d.\n", result); + return result; +} + +dev_t get_header_dev_t(void) +{ + return prio_chain_head->dev_t; +} + +struct block_device *get_header_bdev(void) +{ + return prio_chain_head->bdev; +} + +unsigned long get_headerblock(void) +{ + return prio_chain_head->blocks.first->start << + prio_chain_head->bmap_shift; +} + +int get_main_pool_phys_params(void) +{ + struct toi_bdev_info *this = prio_chain_head; + int result; + + while (this) { + result = this->allocator->bio_allocator_ops->bmap(this); + if (result) + return result; + this = this->next; + } + + return 0; +} + +static int apply_header_reservation(void) +{ + int i; + + if (!header_pages_reserved) { + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "No header pages reserved at the moment."); + return 0; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Applying header reservation."); + + /* Apply header space reservation */ + toi_extent_state_goto_start(); + + for (i = 0; i < header_pages_reserved; i++) + if (go_next_page(1, 0)) + return -ENOSPC; + + /* The end of header pages will be the start of pageset 2 */ + toi_extent_state_save(2); + + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Finished applying header reservation."); + return 0; +} + +static int toi_bio_register_storage(void) +{ + int result = 0; + struct toi_module_ops *this_module; + + list_for_each_entry(this_module, &toi_modules, module_list) { + if (!this_module->enabled || + this_module->type != BIO_ALLOCATOR_MODULE) + continue; + toi_message(TOI_BIO, TOI_VERBOSE, 0, + "Registering storage from %s.", + this_module->name); + result = this_module->bio_allocator_ops->register_storage(); + if (result) + break; + } + + return result; +} + +void toi_bio_free_unused_storage(void) +{ + struct toi_bdev_info *this = prio_chain_head; + + while (this) { + toi_bio_free_unused_storage_chain(this); + this = this->next; + } +} + +int toi_bio_allocate_storage(unsigned long request) +{ + struct toi_bdev_info *chain = prio_chain_head; + unsigned long to_get = request; + unsigned long extra_pages, needed; + int no_free = 0; + + if (!chain) { + int result = toi_bio_register_storage(); + toi_message(TOI_BIO, TOI_VERBOSE, 0, "toi_bio_allocate_storage: " + "Registering storage."); + if (result) + return 0; + chain = prio_chain_head; + if (!chain) { + printk("TuxOnIce: No storage was registered.\n"); + return 0; + } + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "toi_bio_allocate_storage: " + "Request is %lu pages.", request); + extra_pages = DIV_ROUND_UP(request * (sizeof(unsigned long) + + sizeof(int)), PAGE_SIZE); + needed = request + extra_pages + header_pages_reserved; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Adding %lu extra pages and %lu " + "for header => %lu.", + extra_pages, header_pages_reserved, needed); + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Already allocated %lu pages.", + raw_pages_allocd); + + to_get = needed > raw_pages_allocd ? needed - raw_pages_allocd : 0; + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Need to get %lu pages.", to_get); + + if (!to_get) + return apply_header_reservation(); + + while (to_get && chain) { + int num_group = devices_of_same_priority(chain); + int divisor = num_group - no_free; + int i; + unsigned long portion = DIV_ROUND_UP(to_get, divisor); + unsigned long got = 0; + unsigned long got_this_round = 0; + struct toi_bdev_info *top = chain; + + toi_message(TOI_BIO, TOI_VERBOSE, 0, + " Start of loop. To get is %lu. Divisor is %d.", + to_get, divisor); + no_free = 0; + + /* + * We're aiming to spread the allocated storage as evenly + * as possible, but we also want to get all the storage we + * can off this priority. + */ + for (i = 0; i < num_group; i++) { + struct toi_bio_allocator_ops *ops = + chain->allocator->bio_allocator_ops; + toi_message(TOI_BIO, TOI_VERBOSE, 0, + " Asking for %lu pages from chain %p.", + portion, chain); + got = ops->allocate_storage(chain, portion); + toi_message(TOI_BIO, TOI_VERBOSE, 0, + " Got %lu pages from allocator %p.", + got, chain); + if (!got) + no_free++; + got_this_round += got; + chain = chain->next; + } + toi_message(TOI_BIO, TOI_VERBOSE, 0, " Loop finished. Got a " + "total of %lu pages from %d allocators.", + got_this_round, divisor - no_free); + + raw_pages_allocd += got_this_round; + to_get = needed > raw_pages_allocd ? needed - raw_pages_allocd : + 0; + + /* + * If we got anything from chains of this priority and we + * still have storage to allocate, go over this priority + * again. + */ + if (got_this_round && to_get) + chain = top; + else + no_free = 0; + } + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Finished allocating. Calling " + "get_main_pool_phys_params"); + /* Now let swap allocator bmap the pages */ + get_main_pool_phys_params(); + + toi_message(TOI_BIO, TOI_VERBOSE, 0, "Done. Reserving header."); + return apply_header_reservation(); +} + +void toi_bio_chains_post_atomic(struct toi_boot_kernel_data *bkd) +{ + int i = 0; + struct toi_bdev_info *cur_chain = prio_chain_head; + + while (cur_chain) { + cur_chain->pages_used = bkd->pages_used[i]; + cur_chain = cur_chain->next; + i++; + } +} + +int toi_bio_chains_debug_info(char *buffer, int size) +{ + /* Show what we actually used */ + struct toi_bdev_info *cur_chain = prio_chain_head; + int len = 0; + + while (cur_chain) { + len += scnprintf(buffer + len, size - len, " Used %lu pages " + "from %s.\n", cur_chain->pages_used, + cur_chain->name); + cur_chain = cur_chain->next; + } + + return len; +} + +void toi_bio_store_inc_image_ptr(struct toi_incremental_image_pointer *ptr) +{ + struct toi_bdev_info *this = toi_writer_posn.current_chain, + *cmp = prio_chain_head; + + ptr->save.chain = 1; + while (this != cmp) { + ptr->save.chain++; + cmp = cmp->next; + } + ptr->save.block = this->blocks.current_offset; + + /* Save the raw info internally for quicker access when updating pointers */ + ptr->bdev = this->bdev; + ptr->block = this->blocks.current_offset << this->bmap_shift; +} + +void toi_bio_restore_inc_image_ptr(struct toi_incremental_image_pointer *ptr) +{ + int i = ptr->save.chain - 1; + struct toi_bdev_info *this; + struct hibernate_extent *hib; + + /* Find chain by stored index */ + this = prio_chain_head; + while (i) { + this = this->next; + i--; + } + toi_writer_posn.current_chain = this; + + /* Restore block */ + this->blocks.current_offset = ptr->save.block; + + /* Find current offset from block number */ + hib = this->blocks.first; + + while (hib->start > ptr->save.block) { + hib = hib->next; + } + + this->blocks.last_touched = this->blocks.current_extent = hib; +} |