| /* |
| * fs/f2fs/gc.c |
| * |
| * Copyright (c) 2012 Samsung Electronics Co., Ltd. |
| * http://www.samsung.com/ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #include <linux/fs.h> |
| #include <linux/module.h> |
| #include <linux/backing-dev.h> |
| #include <linux/init.h> |
| #include <linux/f2fs_fs.h> |
| #include <linux/kthread.h> |
| #include <linux/delay.h> |
| #include <linux/freezer.h> |
| |
| #include "f2fs.h" |
| #include "node.h" |
| #include "segment.h" |
| #include "gc.h" |
| #include <trace/events/f2fs.h> |
| |
| static int gc_thread_func(void *data) |
| { |
| struct f2fs_sb_info *sbi = data; |
| struct f2fs_gc_kthread *gc_th = sbi->gc_thread; |
| wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head; |
| long wait_ms; |
| |
| wait_ms = gc_th->min_sleep_time; |
| |
| do { |
| if (try_to_freeze()) |
| continue; |
| else |
| wait_event_interruptible_timeout(*wq, |
| kthread_should_stop(), |
| msecs_to_jiffies(wait_ms)); |
| if (kthread_should_stop()) |
| break; |
| |
| if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) { |
| increase_sleep_time(gc_th, &wait_ms); |
| continue; |
| } |
| |
| #ifdef CONFIG_F2FS_FAULT_INJECTION |
| if (time_to_inject(sbi, FAULT_CHECKPOINT)) |
| f2fs_stop_checkpoint(sbi, false); |
| #endif |
| |
| /* |
| * [GC triggering condition] |
| * 0. GC is not conducted currently. |
| * 1. There are enough dirty segments. |
| * 2. IO subsystem is idle by checking the # of writeback pages. |
| * 3. IO subsystem is idle by checking the # of requests in |
| * bdev's request list. |
| * |
| * Note) We have to avoid triggering GCs frequently. |
| * Because it is possible that some segments can be |
| * invalidated soon after by user update or deletion. |
| * So, I'd like to wait some time to collect dirty segments. |
| */ |
| if (!mutex_trylock(&sbi->gc_mutex)) |
| continue; |
| |
| if (!is_idle(sbi)) { |
| increase_sleep_time(gc_th, &wait_ms); |
| mutex_unlock(&sbi->gc_mutex); |
| continue; |
| } |
| |
| if (has_enough_invalid_blocks(sbi)) |
| decrease_sleep_time(gc_th, &wait_ms); |
| else |
| increase_sleep_time(gc_th, &wait_ms); |
| |
| stat_inc_bggc_count(sbi); |
| |
| /* if return value is not zero, no victim was selected */ |
| if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC))) |
| wait_ms = gc_th->no_gc_sleep_time; |
| |
| trace_f2fs_background_gc(sbi->sb, wait_ms, |
| prefree_segments(sbi), free_segments(sbi)); |
| |
| /* balancing f2fs's metadata periodically */ |
| f2fs_balance_fs_bg(sbi); |
| |
| } while (!kthread_should_stop()); |
| return 0; |
| } |
| |
| int start_gc_thread(struct f2fs_sb_info *sbi) |
| { |
| struct f2fs_gc_kthread *gc_th; |
| dev_t dev = sbi->sb->s_bdev->bd_dev; |
| int err = 0; |
| |
| gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL); |
| if (!gc_th) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; |
| gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; |
| gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; |
| |
| gc_th->gc_idle = 0; |
| |
| sbi->gc_thread = gc_th; |
| init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); |
| sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, |
| "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); |
| if (IS_ERR(gc_th->f2fs_gc_task)) { |
| err = PTR_ERR(gc_th->f2fs_gc_task); |
| kfree(gc_th); |
| sbi->gc_thread = NULL; |
| } |
| out: |
| return err; |
| } |
| |
| void stop_gc_thread(struct f2fs_sb_info *sbi) |
| { |
| struct f2fs_gc_kthread *gc_th = sbi->gc_thread; |
| if (!gc_th) |
| return; |
| kthread_stop(gc_th->f2fs_gc_task); |
| kfree(gc_th); |
| sbi->gc_thread = NULL; |
| } |
| |
| static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) |
| { |
| int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; |
| |
| if (gc_th && gc_th->gc_idle) { |
| if (gc_th->gc_idle == 1) |
| gc_mode = GC_CB; |
| else if (gc_th->gc_idle == 2) |
| gc_mode = GC_GREEDY; |
| } |
| return gc_mode; |
| } |
| |
| static void select_policy(struct f2fs_sb_info *sbi, int gc_type, |
| int type, struct victim_sel_policy *p) |
| { |
| struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); |
| |
| if (p->alloc_mode == SSR) { |
| p->gc_mode = GC_GREEDY; |
| p->dirty_segmap = dirty_i->dirty_segmap[type]; |
| p->max_search = dirty_i->nr_dirty[type]; |
| p->ofs_unit = 1; |
| } else { |
| p->gc_mode = select_gc_type(sbi->gc_thread, gc_type); |
| p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; |
| p->max_search = dirty_i->nr_dirty[DIRTY]; |
| p->ofs_unit = sbi->segs_per_sec; |
| } |
| |
| if (p->max_search > sbi->max_victim_search) |
| p->max_search = sbi->max_victim_search; |
| |
| p->offset = sbi->last_victim[p->gc_mode]; |
| } |
| |
| static unsigned int get_max_cost(struct f2fs_sb_info *sbi, |
| struct victim_sel_policy *p) |
| { |
| /* SSR allocates in a segment unit */ |
| if (p->alloc_mode == SSR) |
| return sbi->blocks_per_seg; |
| if (p->gc_mode == GC_GREEDY) |
| return sbi->blocks_per_seg * p->ofs_unit; |
| else if (p->gc_mode == GC_CB) |
| return UINT_MAX; |
| else /* No other gc_mode */ |
| return 0; |
| } |
| |
| static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) |
| { |
| struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); |
| unsigned int secno; |
| |
| /* |
| * If the gc_type is FG_GC, we can select victim segments |
| * selected by background GC before. |
| * Those segments guarantee they have small valid blocks. |
| */ |
| for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { |
| if (sec_usage_check(sbi, secno)) |
| continue; |
| clear_bit(secno, dirty_i->victim_secmap); |
| return secno * sbi->segs_per_sec; |
| } |
| return NULL_SEGNO; |
| } |
| |
| static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) |
| { |
| struct sit_info *sit_i = SIT_I(sbi); |
| unsigned int secno = GET_SECNO(sbi, segno); |
| unsigned int start = secno * sbi->segs_per_sec; |
| unsigned long long mtime = 0; |
| unsigned int vblocks; |
| unsigned char age = 0; |
| unsigned char u; |
| unsigned int i; |
| |
| for (i = 0; i < sbi->segs_per_sec; i++) |
| mtime += get_seg_entry(sbi, start + i)->mtime; |
| vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec); |
| |
| mtime = div_u64(mtime, sbi->segs_per_sec); |
| vblocks = div_u64(vblocks, sbi->segs_per_sec); |
| |
| u = (vblocks * 100) >> sbi->log_blocks_per_seg; |
| |
| /* Handle if the system time has changed by the user */ |
| if (mtime < sit_i->min_mtime) |
| sit_i->min_mtime = mtime; |
| if (mtime > sit_i->max_mtime) |
| sit_i->max_mtime = mtime; |
| if (sit_i->max_mtime != sit_i->min_mtime) |
| age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), |
| sit_i->max_mtime - sit_i->min_mtime); |
| |
| return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); |
| } |
| |
| static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, |
| unsigned int segno, struct victim_sel_policy *p) |
| { |
| if (p->alloc_mode == SSR) |
| return get_seg_entry(sbi, segno)->ckpt_valid_blocks; |
| |
| /* alloc_mode == LFS */ |
| if (p->gc_mode == GC_GREEDY) |
| return get_valid_blocks(sbi, segno, sbi->segs_per_sec); |
| else |
| return get_cb_cost(sbi, segno); |
| } |
| |
| static unsigned int count_bits(const unsigned long *addr, |
| unsigned int offset, unsigned int len) |
| { |
| unsigned int end = offset + len, sum = 0; |
| |
| while (offset < end) { |
| if (test_bit(offset++, addr)) |
| ++sum; |
| } |
| return sum; |
| } |
| |
| /* |
| * This function is called from two paths. |
| * One is garbage collection and the other is SSR segment selection. |
| * When it is called during GC, it just gets a victim segment |
| * and it does not remove it from dirty seglist. |
| * When it is called from SSR segment selection, it finds a segment |
| * which has minimum valid blocks and removes it from dirty seglist. |
| */ |
| static int get_victim_by_default(struct f2fs_sb_info *sbi, |
| unsigned int *result, int gc_type, int type, char alloc_mode) |
| { |
| struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); |
| struct victim_sel_policy p; |
| unsigned int secno, last_victim; |
| unsigned int last_segment = MAIN_SEGS(sbi); |
| unsigned int nsearched = 0; |
| |
| mutex_lock(&dirty_i->seglist_lock); |
| |
| p.alloc_mode = alloc_mode; |
| select_policy(sbi, gc_type, type, &p); |
| |
| p.min_segno = NULL_SEGNO; |
| p.min_cost = get_max_cost(sbi, &p); |
| |
| if (p.max_search == 0) |
| goto out; |
| |
| last_victim = sbi->last_victim[p.gc_mode]; |
| if (p.alloc_mode == LFS && gc_type == FG_GC) { |
| p.min_segno = check_bg_victims(sbi); |
| if (p.min_segno != NULL_SEGNO) |
| goto got_it; |
| } |
| |
| while (1) { |
| unsigned long cost; |
| unsigned int segno; |
| |
| segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); |
| if (segno >= last_segment) { |
| if (sbi->last_victim[p.gc_mode]) { |
| last_segment = sbi->last_victim[p.gc_mode]; |
| sbi->last_victim[p.gc_mode] = 0; |
| p.offset = 0; |
| continue; |
| } |
| break; |
| } |
| |
| p.offset = segno + p.ofs_unit; |
| if (p.ofs_unit > 1) { |
| p.offset -= segno % p.ofs_unit; |
| nsearched += count_bits(p.dirty_segmap, |
| p.offset - p.ofs_unit, |
| p.ofs_unit); |
| } else { |
| nsearched++; |
| } |
| |
| |
| secno = GET_SECNO(sbi, segno); |
| |
| if (sec_usage_check(sbi, secno)) |
| goto next; |
| if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) |
| goto next; |
| |
| cost = get_gc_cost(sbi, segno, &p); |
| |
| if (p.min_cost > cost) { |
| p.min_segno = segno; |
| p.min_cost = cost; |
| } |
| next: |
| if (nsearched >= p.max_search) { |
| if (!sbi->last_victim[p.gc_mode] && segno <= last_victim) |
| sbi->last_victim[p.gc_mode] = last_victim + 1; |
| else |
| sbi->last_victim[p.gc_mode] = segno + 1; |
| break; |
| } |
| } |
| if (p.min_segno != NULL_SEGNO) { |
| got_it: |
| if (p.alloc_mode == LFS) { |
| secno = GET_SECNO(sbi, p.min_segno); |
| if (gc_type == FG_GC) |
| sbi->cur_victim_sec = secno; |
| else |
| set_bit(secno, dirty_i->victim_secmap); |
| } |
| *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; |
| |
| trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, |
| sbi->cur_victim_sec, |
| prefree_segments(sbi), free_segments(sbi)); |
| } |
| out: |
| mutex_unlock(&dirty_i->seglist_lock); |
| |
| return (p.min_segno == NULL_SEGNO) ? 0 : 1; |
| } |
| |
| static const struct victim_selection default_v_ops = { |
| .get_victim = get_victim_by_default, |
| }; |
| |
| static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) |
| { |
| struct inode_entry *ie; |
| |
| ie = radix_tree_lookup(&gc_list->iroot, ino); |
| if (ie) |
| return ie->inode; |
| return NULL; |
| } |
| |
| static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) |
| { |
| struct inode_entry *new_ie; |
| |
| if (inode == find_gc_inode(gc_list, inode->i_ino)) { |
| iput(inode); |
| return; |
| } |
| new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); |
| new_ie->inode = inode; |
| |
| f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); |
| list_add_tail(&new_ie->list, &gc_list->ilist); |
| } |
| |
| static void put_gc_inode(struct gc_inode_list *gc_list) |
| { |
| struct inode_entry *ie, *next_ie; |
| list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { |
| radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); |
| iput(ie->inode); |
| list_del(&ie->list); |
| kmem_cache_free(inode_entry_slab, ie); |
| } |
| } |
| |
| static int check_valid_map(struct f2fs_sb_info *sbi, |
| unsigned int segno, int offset) |
| { |
| struct sit_info *sit_i = SIT_I(sbi); |
| struct seg_entry *sentry; |
| int ret; |
| |
| mutex_lock(&sit_i->sentry_lock); |
| sentry = get_seg_entry(sbi, segno); |
| ret = f2fs_test_bit(offset, sentry->cur_valid_map); |
| mutex_unlock(&sit_i->sentry_lock); |
| return ret; |
| } |
| |
| /* |
| * This function compares node address got in summary with that in NAT. |
| * On validity, copy that node with cold status, otherwise (invalid node) |
| * ignore that. |
| */ |
| static void gc_node_segment(struct f2fs_sb_info *sbi, |
| struct f2fs_summary *sum, unsigned int segno, int gc_type) |
| { |
| struct f2fs_summary *entry; |
| block_t start_addr; |
| int off; |
| int phase = 0; |
| |
| start_addr = START_BLOCK(sbi, segno); |
| |
| next_step: |
| entry = sum; |
| |
| for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { |
| nid_t nid = le32_to_cpu(entry->nid); |
| struct page *node_page; |
| struct node_info ni; |
| |
| /* stop BG_GC if there is not enough free sections. */ |
| if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) |
| return; |
| |
| if (check_valid_map(sbi, segno, off) == 0) |
| continue; |
| |
| if (phase == 0) { |
| ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, |
| META_NAT, true); |
| continue; |
| } |
| |
| if (phase == 1) { |
| ra_node_page(sbi, nid); |
| continue; |
| } |
| |
| /* phase == 2 */ |
| node_page = get_node_page(sbi, nid); |
| if (IS_ERR(node_page)) |
| continue; |
| |
| /* block may become invalid during get_node_page */ |
| if (check_valid_map(sbi, segno, off) == 0) { |
| f2fs_put_page(node_page, 1); |
| continue; |
| } |
| |
| get_node_info(sbi, nid, &ni); |
| if (ni.blk_addr != start_addr + off) { |
| f2fs_put_page(node_page, 1); |
| continue; |
| } |
| |
| move_node_page(node_page, gc_type); |
| stat_inc_node_blk_count(sbi, 1, gc_type); |
| } |
| |
| if (++phase < 3) |
| goto next_step; |
| } |
| |
| /* |
| * Calculate start block index indicating the given node offset. |
| * Be careful, caller should give this node offset only indicating direct node |
| * blocks. If any node offsets, which point the other types of node blocks such |
| * as indirect or double indirect node blocks, are given, it must be a caller's |
| * bug. |
| */ |
| block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode) |
| { |
| unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; |
| unsigned int bidx; |
| |
| if (node_ofs == 0) |
| return 0; |
| |
| if (node_ofs <= 2) { |
| bidx = node_ofs - 1; |
| } else if (node_ofs <= indirect_blks) { |
| int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); |
| bidx = node_ofs - 2 - dec; |
| } else { |
| int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); |
| bidx = node_ofs - 5 - dec; |
| } |
| return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode); |
| } |
| |
| static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, |
| struct node_info *dni, block_t blkaddr, unsigned int *nofs) |
| { |
| struct page *node_page; |
| nid_t nid; |
| unsigned int ofs_in_node; |
| block_t source_blkaddr; |
| |
| nid = le32_to_cpu(sum->nid); |
| ofs_in_node = le16_to_cpu(sum->ofs_in_node); |
| |
| node_page = get_node_page(sbi, nid); |
| if (IS_ERR(node_page)) |
| return false; |
| |
| get_node_info(sbi, nid, dni); |
| |
| if (sum->version != dni->version) { |
| f2fs_put_page(node_page, 1); |
| return false; |
| } |
| |
| *nofs = ofs_of_node(node_page); |
| source_blkaddr = datablock_addr(node_page, ofs_in_node); |
| f2fs_put_page(node_page, 1); |
| |
| if (source_blkaddr != blkaddr) |
| return false; |
| return true; |
| } |
| |
| static void move_encrypted_block(struct inode *inode, block_t bidx) |
| { |
| struct f2fs_io_info fio = { |
| .sbi = F2FS_I_SB(inode), |
| .type = DATA, |
| .op = REQ_OP_READ, |
| .op_flags = 0, |
| .encrypted_page = NULL, |
| }; |
| struct dnode_of_data dn; |
| struct f2fs_summary sum; |
| struct node_info ni; |
| struct page *page; |
| block_t newaddr; |
| int err; |
| |
| /* do not read out */ |
| page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); |
| if (!page) |
| return; |
| |
| set_new_dnode(&dn, inode, NULL, NULL, 0); |
| err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); |
| if (err) |
| goto out; |
| |
| if (unlikely(dn.data_blkaddr == NULL_ADDR)) { |
| ClearPageUptodate(page); |
| goto put_out; |
| } |
| |
| /* |
| * don't cache encrypted data into meta inode until previous dirty |
| * data were writebacked to avoid racing between GC and flush. |
| */ |
| f2fs_wait_on_page_writeback(page, DATA, true); |
| |
| get_node_info(fio.sbi, dn.nid, &ni); |
| set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); |
| |
| /* read page */ |
| fio.page = page; |
| fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; |
| |
| allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, |
| &sum, CURSEG_COLD_DATA); |
| |
| fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr, |
| FGP_LOCK | FGP_CREAT, GFP_NOFS); |
| if (!fio.encrypted_page) { |
| err = -ENOMEM; |
| goto recover_block; |
| } |
| |
| err = f2fs_submit_page_bio(&fio); |
| if (err) |
| goto put_page_out; |
| |
| /* write page */ |
| lock_page(fio.encrypted_page); |
| |
| if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { |
| err = -EIO; |
| goto put_page_out; |
| } |
| if (unlikely(!PageUptodate(fio.encrypted_page))) { |
| err = -EIO; |
| goto put_page_out; |
| } |
| |
| set_page_dirty(fio.encrypted_page); |
| f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true); |
| if (clear_page_dirty_for_io(fio.encrypted_page)) |
| dec_page_count(fio.sbi, F2FS_DIRTY_META); |
| |
| set_page_writeback(fio.encrypted_page); |
| |
| /* allocate block address */ |
| f2fs_wait_on_page_writeback(dn.node_page, NODE, true); |
| |
| fio.op = REQ_OP_WRITE; |
| fio.op_flags = REQ_SYNC; |
| fio.new_blkaddr = newaddr; |
| f2fs_submit_page_mbio(&fio); |
| |
| f2fs_update_data_blkaddr(&dn, newaddr); |
| set_inode_flag(inode, FI_APPEND_WRITE); |
| if (page->index == 0) |
| set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN); |
| put_page_out: |
| f2fs_put_page(fio.encrypted_page, 1); |
| recover_block: |
| if (err) |
| __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, |
| true, true); |
| put_out: |
| f2fs_put_dnode(&dn); |
| out: |
| f2fs_put_page(page, 1); |
| } |
| |
| static void move_data_page(struct inode *inode, block_t bidx, int gc_type) |
| { |
| struct page *page; |
| |
| page = get_lock_data_page(inode, bidx, true); |
| if (IS_ERR(page)) |
| return; |
| |
| if (gc_type == BG_GC) { |
| if (PageWriteback(page)) |
| goto out; |
| set_page_dirty(page); |
| set_cold_data(page); |
| } else { |
| struct f2fs_io_info fio = { |
| .sbi = F2FS_I_SB(inode), |
| .type = DATA, |
| .op = REQ_OP_WRITE, |
| .op_flags = REQ_SYNC, |
| .page = page, |
| .encrypted_page = NULL, |
| }; |
| bool is_dirty = PageDirty(page); |
| int err; |
| |
| retry: |
| set_page_dirty(page); |
| f2fs_wait_on_page_writeback(page, DATA, true); |
| if (clear_page_dirty_for_io(page)) |
| inode_dec_dirty_pages(inode); |
| |
| set_cold_data(page); |
| |
| err = do_write_data_page(&fio); |
| if (err == -ENOMEM && is_dirty) { |
| congestion_wait(BLK_RW_ASYNC, HZ/50); |
| goto retry; |
| } |
| |
| clear_cold_data(page); |
| } |
| out: |
| f2fs_put_page(page, 1); |
| } |
| |
| /* |
| * This function tries to get parent node of victim data block, and identifies |
| * data block validity. If the block is valid, copy that with cold status and |
| * modify parent node. |
| * If the parent node is not valid or the data block address is different, |
| * the victim data block is ignored. |
| */ |
| static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, |
| struct gc_inode_list *gc_list, unsigned int segno, int gc_type) |
| { |
| struct super_block *sb = sbi->sb; |
| struct f2fs_summary *entry; |
| block_t start_addr; |
| int off; |
| int phase = 0; |
| |
| start_addr = START_BLOCK(sbi, segno); |
| |
| next_step: |
| entry = sum; |
| |
| for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { |
| struct page *data_page; |
| struct inode *inode; |
| struct node_info dni; /* dnode info for the data */ |
| unsigned int ofs_in_node, nofs; |
| block_t start_bidx; |
| nid_t nid = le32_to_cpu(entry->nid); |
| |
| /* stop BG_GC if there is not enough free sections. */ |
| if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) |
| return; |
| |
| if (check_valid_map(sbi, segno, off) == 0) |
| continue; |
| |
| if (phase == 0) { |
| ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, |
| META_NAT, true); |
| continue; |
| } |
| |
| if (phase == 1) { |
| ra_node_page(sbi, nid); |
| continue; |
| } |
| |
| /* Get an inode by ino with checking validity */ |
| if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) |
| continue; |
| |
| if (phase == 2) { |
| ra_node_page(sbi, dni.ino); |
| continue; |
| } |
| |
| ofs_in_node = le16_to_cpu(entry->ofs_in_node); |
| |
| if (phase == 3) { |
| inode = f2fs_iget(sb, dni.ino); |
| if (IS_ERR(inode) || is_bad_inode(inode)) |
| continue; |
| |
| /* if encrypted inode, let's go phase 3 */ |
| if (f2fs_encrypted_inode(inode) && |
| S_ISREG(inode->i_mode)) { |
| add_gc_inode(gc_list, inode); |
| continue; |
| } |
| |
| start_bidx = start_bidx_of_node(nofs, inode); |
| data_page = get_read_data_page(inode, |
| start_bidx + ofs_in_node, REQ_RAHEAD, |
| true); |
| if (IS_ERR(data_page)) { |
| iput(inode); |
| continue; |
| } |
| |
| f2fs_put_page(data_page, 0); |
| add_gc_inode(gc_list, inode); |
| continue; |
| } |
| |
| /* phase 4 */ |
| inode = find_gc_inode(gc_list, dni.ino); |
| if (inode) { |
| struct f2fs_inode_info *fi = F2FS_I(inode); |
| bool locked = false; |
| |
| if (S_ISREG(inode->i_mode)) { |
| if (!down_write_trylock(&fi->dio_rwsem[READ])) |
| continue; |
| if (!down_write_trylock( |
| &fi->dio_rwsem[WRITE])) { |
| up_write(&fi->dio_rwsem[READ]); |
| continue; |
| } |
| locked = true; |
| } |
| |
| start_bidx = start_bidx_of_node(nofs, inode) |
| + ofs_in_node; |
| if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) |
| move_encrypted_block(inode, start_bidx); |
| else |
| move_data_page(inode, start_bidx, gc_type); |
| |
| if (locked) { |
| up_write(&fi->dio_rwsem[WRITE]); |
| up_write(&fi->dio_rwsem[READ]); |
| } |
| |
| stat_inc_data_blk_count(sbi, 1, gc_type); |
| } |
| } |
| |
| if (++phase < 5) |
| goto next_step; |
| } |
| |
| static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, |
| int gc_type) |
| { |
| struct sit_info *sit_i = SIT_I(sbi); |
| int ret; |
| |
| mutex_lock(&sit_i->sentry_lock); |
| ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, |
| NO_CHECK_TYPE, LFS); |
| mutex_unlock(&sit_i->sentry_lock); |
| return ret; |
| } |
| |
| static int do_garbage_collect(struct f2fs_sb_info *sbi, |
| unsigned int start_segno, |
| struct gc_inode_list *gc_list, int gc_type) |
| { |
| struct page *sum_page; |
| struct f2fs_summary_block *sum; |
| struct blk_plug plug; |
| unsigned int segno = start_segno; |
| unsigned int end_segno = start_segno + sbi->segs_per_sec; |
| int sec_freed = 0; |
| unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ? |
| SUM_TYPE_DATA : SUM_TYPE_NODE; |
| |
| /* readahead multi ssa blocks those have contiguous address */ |
| if (sbi->segs_per_sec > 1) |
| ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), |
| sbi->segs_per_sec, META_SSA, true); |
| |
| /* reference all summary page */ |
| while (segno < end_segno) { |
| sum_page = get_sum_page(sbi, segno++); |
| unlock_page(sum_page); |
| } |
| |
| blk_start_plug(&plug); |
| |
| for (segno = start_segno; segno < end_segno; segno++) { |
| |
| /* find segment summary of victim */ |
| sum_page = find_get_page(META_MAPPING(sbi), |
| GET_SUM_BLOCK(sbi, segno)); |
| f2fs_put_page(sum_page, 0); |
| |
| if (get_valid_blocks(sbi, segno, 1) == 0 || |
| !PageUptodate(sum_page) || |
| unlikely(f2fs_cp_error(sbi))) |
| goto next; |
| |
| sum = page_address(sum_page); |
| f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer))); |
| |
| /* |
| * this is to avoid deadlock: |
| * - lock_page(sum_page) - f2fs_replace_block |
| * - check_valid_map() - mutex_lock(sentry_lock) |
| * - mutex_lock(sentry_lock) - change_curseg() |
| * - lock_page(sum_page) |
| */ |
| |
| if (type == SUM_TYPE_NODE) |
| gc_node_segment(sbi, sum->entries, segno, gc_type); |
| else |
| gc_data_segment(sbi, sum->entries, gc_list, segno, |
| gc_type); |
| |
| stat_inc_seg_count(sbi, type, gc_type); |
| next: |
| f2fs_put_page(sum_page, 0); |
| } |
| |
| if (gc_type == FG_GC) |
| f2fs_submit_merged_bio(sbi, |
| (type == SUM_TYPE_NODE) ? NODE : DATA, WRITE); |
| |
| blk_finish_plug(&plug); |
| |
| if (gc_type == FG_GC && |
| get_valid_blocks(sbi, start_segno, sbi->segs_per_sec) == 0) |
| sec_freed = 1; |
| |
| stat_inc_call_count(sbi->stat_info); |
| |
| return sec_freed; |
| } |
| |
| int f2fs_gc(struct f2fs_sb_info *sbi, bool sync) |
| { |
| unsigned int segno; |
| int gc_type = sync ? FG_GC : BG_GC; |
| int sec_freed = 0; |
| int ret = -EINVAL; |
| struct cp_control cpc; |
| struct gc_inode_list gc_list = { |
| .ilist = LIST_HEAD_INIT(gc_list.ilist), |
| .iroot = RADIX_TREE_INIT(GFP_NOFS), |
| }; |
| |
| cpc.reason = __get_cp_reason(sbi); |
| gc_more: |
| segno = NULL_SEGNO; |
| |
| if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) |
| goto stop; |
| if (unlikely(f2fs_cp_error(sbi))) { |
| ret = -EIO; |
| goto stop; |
| } |
| |
| if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed, 0)) { |
| gc_type = FG_GC; |
| /* |
| * If there is no victim and no prefree segment but still not |
| * enough free sections, we should flush dent/node blocks and do |
| * garbage collections. |
| */ |
| if (__get_victim(sbi, &segno, gc_type) || |
| prefree_segments(sbi)) { |
| ret = write_checkpoint(sbi, &cpc); |
| if (ret) |
| goto stop; |
| segno = NULL_SEGNO; |
| } else if (has_not_enough_free_secs(sbi, 0, 0)) { |
| ret = write_checkpoint(sbi, &cpc); |
| if (ret) |
| goto stop; |
| } |
| } |
| |
| if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type)) |
| goto stop; |
| ret = 0; |
| |
| if (do_garbage_collect(sbi, segno, &gc_list, gc_type) && |
| gc_type == FG_GC) |
| sec_freed++; |
| |
| if (gc_type == FG_GC) |
| sbi->cur_victim_sec = NULL_SEGNO; |
| |
| if (!sync) { |
| if (has_not_enough_free_secs(sbi, sec_freed, 0)) |
| goto gc_more; |
| |
| if (gc_type == FG_GC) |
| ret = write_checkpoint(sbi, &cpc); |
| } |
| stop: |
| mutex_unlock(&sbi->gc_mutex); |
| |
| put_gc_inode(&gc_list); |
| |
| if (sync) |
| ret = sec_freed ? 0 : -EAGAIN; |
| return ret; |
| } |
| |
| void build_gc_manager(struct f2fs_sb_info *sbi) |
| { |
| DIRTY_I(sbi)->v_ops = &default_v_ops; |
| } |