/* * 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 #include #include #include #include #include #include #include #include "f2fs.h" #include "node.h" #include "segment.h" #include "gc.h" #include 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; unsigned int wait_ms; wait_ms = gc_th->min_sleep_time; set_freezable(); do { wait_event_interruptible_timeout(*wq, kthread_should_stop() || freezing(current) || gc_th->gc_wake, msecs_to_jiffies(wait_ms)); /* give it a try one time */ if (gc_th->gc_wake) gc_th->gc_wake = 0; if (try_to_freeze()) continue; 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_show_injection_info(FAULT_CHECKPOINT); f2fs_stop_checkpoint(sbi, false); } #endif if (!sb_start_write_trylock(sbi->sb)) continue; /* * [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 (sbi->gc_mode == GC_URGENT) { wait_ms = gc_th->urgent_sleep_time; mutex_lock(&sbi->gc_mutex); goto do_gc; } if (!mutex_trylock(&sbi->gc_mutex)) goto next; if (!is_idle(sbi)) { increase_sleep_time(gc_th, &wait_ms); mutex_unlock(&sbi->gc_mutex); goto next; } if (has_enough_invalid_blocks(sbi)) decrease_sleep_time(gc_th, &wait_ms); else increase_sleep_time(gc_th, &wait_ms); do_gc: 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), true, NULL_SEGNO)) 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); next: sb_end_write(sbi->sb); } while (!kthread_should_stop()); return 0; } int f2fs_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->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME; 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_wake= 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 f2fs_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_sb_info *sbi, int gc_type) { int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; switch (sbi->gc_mode) { case GC_IDLE_CB: gc_mode = GC_CB; break; case GC_IDLE_GREEDY: case GC_URGENT: gc_mode = GC_GREEDY; break; } 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_type); p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; p->max_search = dirty_i->nr_dirty[DIRTY]; p->ofs_unit = sbi->segs_per_sec; } /* we need to check every dirty segments in the FG_GC case */ if (gc_type != FG_GC && (sbi->gc_mode != GC_URGENT) && p->max_search > sbi->max_victim_search) p->max_search = sbi->max_victim_search; /* let's select beginning hot/small space first in no_heap mode*/ if (test_opt(sbi, NOHEAP) && (type == CURSEG_HOT_DATA || IS_NODESEG(type))) p->offset = 0; else p->offset = SIT_I(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 2 * 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 GET_SEG_FROM_SEC(sbi, secno); } 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_SEC_FROM_SEG(sbi, segno); unsigned int start = GET_SEG_FROM_SEC(sbi, secno); 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, true); 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, true); 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 sit_info *sm = SIT_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 (*result != NULL_SEGNO) { if (IS_DATASEG(get_seg_entry(sbi, *result)->type) && get_valid_blocks(sbi, *result, false) && !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result))) p.min_segno = *result; goto out; } if (p.max_search == 0) goto out; last_victim = sm->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 (sm->last_victim[p.gc_mode]) { last_segment = sm->last_victim[p.gc_mode]; sm->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_SEC_FROM_SEG(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 (!sm->last_victim[p.gc_mode] && segno <= last_victim) sm->last_victim[p.gc_mode] = last_victim + 1; else sm->last_victim[p.gc_mode] = segno + 1; sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi); break; } } if (p.min_segno != NULL_SEGNO) { got_it: if (p.alloc_mode == LFS) { secno = GET_SEC_FROM_SEG(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(f2fs_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(f2fs_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; down_read(&sit_i->sentry_lock); sentry = get_seg_entry(sbi, segno); ret = f2fs_test_bit(offset, sentry->cur_valid_map); up_read(&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) { f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, META_NAT, true); continue; } if (phase == 1) { f2fs_ra_node_page(sbi, nid); continue; } /* phase == 2 */ node_page = f2fs_get_node_page(sbi, nid); if (IS_ERR(node_page)) continue; /* block may become invalid during f2fs_get_node_page */ if (check_valid_map(sbi, segno, off) == 0) { f2fs_put_page(node_page, 1); continue; } f2fs_get_node_info(sbi, nid, &ni); if (ni.blk_addr != start_addr + off) { f2fs_put_page(node_page, 1); continue; } f2fs_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 f2fs_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 = f2fs_get_node_page(sbi, nid); if (IS_ERR(node_page)) return false; f2fs_get_node_info(sbi, nid, dni); if (sum->version != dni->version) { f2fs_msg(sbi->sb, KERN_WARNING, "%s: valid data with mismatched node version.", __func__); set_sbi_flag(sbi, SBI_NEED_FSCK); } *nofs = ofs_of_node(node_page); source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); f2fs_put_page(node_page, 1); if (source_blkaddr != blkaddr) return false; return true; } /* * Move data block via META_MAPPING while keeping locked data page. * This can be used to move blocks, aka LBAs, directly on disk. */ static void move_data_block(struct inode *inode, block_t bidx, int gc_type, unsigned int segno, int off) { struct f2fs_io_info fio = { .sbi = F2FS_I_SB(inode), .ino = inode->i_ino, .type = DATA, .temp = COLD, .op = REQ_OP_READ, .op_flags = 0, .encrypted_page = NULL, .in_list = false, .retry = false, }; struct dnode_of_data dn; struct f2fs_summary sum; struct node_info ni; struct page *page; block_t newaddr; int err; bool lfs_mode = test_opt(fio.sbi, LFS); /* do not read out */ page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); if (!page) return; if (!check_valid_map(F2FS_I_SB(inode), segno, off)) goto out; if (f2fs_is_atomic_file(inode)) { F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++; F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++; goto out; } if (f2fs_is_pinned_file(inode)) { f2fs_pin_file_control(inode, true); goto out; } set_new_dnode(&dn, inode, NULL, NULL, 0); err = f2fs_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); f2fs_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; if (lfs_mode) down_write(&fio.sbi->io_order_lock); f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, &sum, CURSEG_COLD_DATA, NULL, false); fio.encrypted_page = f2fs_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); ClearPageError(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_write(&fio); if (fio.retry) { if (PageWriteback(fio.encrypted_page)) end_page_writeback(fio.encrypted_page); goto put_page_out; } f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE); 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 (lfs_mode) up_write(&fio.sbi->io_order_lock); if (err) f2fs_do_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, unsigned int segno, int off) { struct page *page; page = f2fs_get_lock_data_page(inode, bidx, true); if (IS_ERR(page)) return; if (!check_valid_map(F2FS_I_SB(inode), segno, off)) goto out; if (f2fs_is_atomic_file(inode)) { F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++; F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++; goto out; } if (f2fs_is_pinned_file(inode)) { if (gc_type == FG_GC) f2fs_pin_file_control(inode, true); goto out; } 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), .ino = inode->i_ino, .type = DATA, .temp = COLD, .op = REQ_OP_WRITE, .op_flags = REQ_SYNC, .old_blkaddr = NULL_ADDR, .page = page, .encrypted_page = NULL, .need_lock = LOCK_REQ, .io_type = FS_GC_DATA_IO, }; 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); f2fs_remove_dirty_inode(inode); } set_cold_data(page); err = f2fs_do_write_data_page(&fio); if (err) { clear_cold_data(page); if (err == -ENOMEM) { congestion_wait(BLK_RW_ASYNC, HZ/50); goto retry; } if (is_dirty) set_page_dirty(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) { f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, META_NAT, true); continue; } if (phase == 1) { f2fs_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) { f2fs_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 inode uses special I/O path, let's go phase 3 */ if (f2fs_post_read_required(inode)) { add_gc_inode(gc_list, inode); continue; } if (!down_write_trylock( &F2FS_I(inode)->i_gc_rwsem[WRITE])) { iput(inode); continue; } start_bidx = f2fs_start_bidx_of_node(nofs, inode); data_page = f2fs_get_read_data_page(inode, start_bidx + ofs_in_node, REQ_RAHEAD, true); up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); 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->i_gc_rwsem[READ])) continue; if (!down_write_trylock( &fi->i_gc_rwsem[WRITE])) { up_write(&fi->i_gc_rwsem[READ]); continue; } locked = true; /* wait for all inflight aio data */ inode_dio_wait(inode); } start_bidx = f2fs_start_bidx_of_node(nofs, inode) + ofs_in_node; if (f2fs_post_read_required(inode)) move_data_block(inode, start_bidx, gc_type, segno, off); else move_data_page(inode, start_bidx, gc_type, segno, off); if (locked) { up_write(&fi->i_gc_rwsem[WRITE]); up_write(&fi->i_gc_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; down_write(&sit_i->sentry_lock); ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, NO_CHECK_TYPE, LFS); up_write(&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 seg_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) f2fs_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 = f2fs_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, false) == 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() - down_write(sentry_lock) * - down_read(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); if (gc_type == FG_GC && get_valid_blocks(sbi, segno, false) == 0) seg_freed++; next: f2fs_put_page(sum_page, 0); } if (gc_type == FG_GC) f2fs_submit_merged_write(sbi, (type == SUM_TYPE_NODE) ? NODE : DATA); blk_finish_plug(&plug); stat_inc_call_count(sbi->stat_info); return seg_freed; } int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, bool background, unsigned int segno) { int gc_type = sync ? FG_GC : BG_GC; int sec_freed = 0, seg_freed = 0, total_freed = 0; int ret = 0; struct cp_control cpc; unsigned int init_segno = segno; struct gc_inode_list gc_list = { .ilist = LIST_HEAD_INIT(gc_list.ilist), .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS), }; unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC]; unsigned int skipped_round = 0, round = 0; trace_f2fs_gc_begin(sbi->sb, sync, background, get_pages(sbi, F2FS_DIRTY_NODES), get_pages(sbi, F2FS_DIRTY_DENTS), get_pages(sbi, F2FS_DIRTY_IMETA), free_sections(sbi), free_segments(sbi), reserved_segments(sbi), prefree_segments(sbi)); cpc.reason = __get_cp_reason(sbi); gc_more: if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) { ret = -EINVAL; goto stop; } if (unlikely(f2fs_cp_error(sbi))) { ret = -EIO; goto stop; } if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) { /* * For example, if there are many prefree_segments below given * threshold, we can make them free by checkpoint. Then, we * secure free segments which doesn't need fggc any more. */ if (prefree_segments(sbi)) { ret = f2fs_write_checkpoint(sbi, &cpc); if (ret) goto stop; } if (has_not_enough_free_secs(sbi, 0, 0)) gc_type = FG_GC; } /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ if (gc_type == BG_GC && !background) { ret = -EINVAL; goto stop; } if (!__get_victim(sbi, &segno, gc_type)) { ret = -ENODATA; goto stop; } seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) sec_freed++; total_freed += seg_freed; if (gc_type == FG_GC) { if (sbi->skipped_atomic_files[FG_GC] > last_skipped) skipped_round++; last_skipped = sbi->skipped_atomic_files[FG_GC]; round++; } if (gc_type == FG_GC) sbi->cur_victim_sec = NULL_SEGNO; if (!sync) { if (has_not_enough_free_secs(sbi, sec_freed, 0)) { if (skipped_round > MAX_SKIP_ATOMIC_COUNT && skipped_round * 2 >= round) f2fs_drop_inmem_pages_all(sbi, true); segno = NULL_SEGNO; goto gc_more; } if (gc_type == FG_GC) ret = f2fs_write_checkpoint(sbi, &cpc); } stop: SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0; SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno; trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed, get_pages(sbi, F2FS_DIRTY_NODES), get_pages(sbi, F2FS_DIRTY_DENTS), get_pages(sbi, F2FS_DIRTY_IMETA), free_sections(sbi), free_segments(sbi), reserved_segments(sbi), prefree_segments(sbi)); mutex_unlock(&sbi->gc_mutex); put_gc_inode(&gc_list); if (sync) ret = sec_freed ? 0 : -EAGAIN; return ret; } void f2fs_build_gc_manager(struct f2fs_sb_info *sbi) { DIRTY_I(sbi)->v_ops = &default_v_ops; sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES; /* give warm/cold data area from slower device */ if (sbi->s_ndevs && sbi->segs_per_sec == 1) SIT_I(sbi)->last_victim[ALLOC_NEXT] = GET_SEGNO(sbi, FDEV(0).end_blk) + 1; }