diff options
Diffstat (limited to 'fs/f2fs/gc.c')
| -rw-r--r-- | fs/f2fs/gc.c | 1269 |
1 files changed, 1269 insertions, 0 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c new file mode 100644 index 000000000..ff447bbb5 --- /dev/null +++ b/fs/f2fs/gc.c @@ -0,0 +1,1269 @@ +/* + * 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; + 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; + } + + if (time_to_inject(sbi, FAULT_CHECKPOINT)) { + f2fs_show_injection_info(FAULT_CHECKPOINT); + f2fs_stop_checkpoint(sbi, false); + } + + 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 (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; + bool fggc = (gc_type == FG_GC); + + start_addr = START_BLOCK(sbi, segno); + +next_step: + entry = sum; + + if (fggc && phase == 2) + atomic_inc(&sbi->wb_sync_req[NODE]); + + 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; + } + + if (f2fs_get_node_info(sbi, nid, &ni)) { + f2fs_put_page(node_page, 1); + continue; + } + + 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; + + if (fggc) + atomic_dec(&sbi->wb_sync_req[NODE]); +} + +/* + * 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; + + if (f2fs_get_node_info(sbi, nid, dni)) { + f2fs_put_page(node_page, 1); + return false; + } + + 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); + } + + if (f2fs_check_nid_range(sbi, dni->ino)) { + f2fs_put_page(node_page, 1); + return false; + } + + *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; +} + +static int ra_data_block(struct inode *inode, pgoff_t index) +{ + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); + struct address_space *mapping = inode->i_mapping; + struct dnode_of_data dn; + struct page *page; + struct extent_info ei = {0, 0, 0}; + struct f2fs_io_info fio = { + .sbi = sbi, + .ino = inode->i_ino, + .type = DATA, + .temp = COLD, + .op = REQ_OP_READ, + .op_flags = 0, + .encrypted_page = NULL, + .in_list = false, + .retry = false, + }; + int err; + + page = f2fs_grab_cache_page(mapping, index, true); + if (!page) + return -ENOMEM; + + if (f2fs_lookup_extent_cache(inode, index, &ei)) { + dn.data_blkaddr = ei.blk + index - ei.fofs; + goto got_it; + } + + set_new_dnode(&dn, inode, NULL, NULL, 0); + err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE); + if (err) + goto put_page; + f2fs_put_dnode(&dn); + + if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr, + DATA_GENERIC))) { + err = -EFSCORRUPTED; + goto put_page; + } +got_it: + /* read page */ + fio.page = page; + fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; + + fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi), + dn.data_blkaddr, + FGP_LOCK | FGP_CREAT, GFP_NOFS); + if (!fio.encrypted_page) { + err = -ENOMEM; + goto put_page; + } + + err = f2fs_submit_page_bio(&fio); + if (err) + goto put_encrypted_page; + f2fs_put_page(fio.encrypted_page, 0); + f2fs_put_page(page, 1); + return 0; +put_encrypted_page: + f2fs_put_page(fio.encrypted_page, 1); +put_page: + f2fs_put_page(page, 1); + return err; +} + +/* + * 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, *mpage; + 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); + + err = f2fs_get_node_info(fio.sbi, dn.nid, &ni); + if (err) + goto put_out; + + 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; + } + + mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi), + fio.old_blkaddr, FGP_LOCK, GFP_NOFS); + if (mpage) { + bool updated = false; + + if (PageUptodate(mpage)) { + memcpy(page_address(fio.encrypted_page), + page_address(mpage), PAGE_SIZE); + updated = true; + } + f2fs_put_page(mpage, 1); + invalidate_mapping_pages(META_MAPPING(fio.sbi), + fio.old_blkaddr, fio.old_blkaddr); + if (updated) + goto write_page; + } + + 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; + } + +write_page: + 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 (!down_write_trylock( + &F2FS_I(inode)->i_gc_rwsem[WRITE])) { + iput(inode); + sbi->skipped_gc_rwsem++; + continue; + } + + start_bidx = f2fs_start_bidx_of_node(nofs, inode) + + ofs_in_node; + + if (f2fs_post_read_required(inode)) { + int err = ra_data_block(inode, start_bidx); + + up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); + if (err) { + iput(inode); + continue; + } + add_gc_inode(gc_list, inode); + continue; + } + + data_page = f2fs_get_read_data_page(inode, + start_bidx, 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])) { + sbi->skipped_gc_rwsem++; + continue; + } + if (!down_write_trylock( + &fi->i_gc_rwsem[WRITE])) { + sbi->skipped_gc_rwsem++; + 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) + goto freed; + if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi))) + goto next; + + sum = page_address(sum_page); + if (type != GET_SUM_TYPE((&sum->footer))) { + f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) " + "type [%d, %d] in SSA and SIT", + segno, type, GET_SUM_TYPE((&sum->footer))); + set_sbi_flag(sbi, SBI_NEED_FSCK); + goto next; + } + + /* + * 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); + +freed: + 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 long long first_skipped; + 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); + sbi->skipped_gc_rwsem = 0; + first_skipped = last_skipped; +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 || + sbi->skipped_gc_rwsem) + skipped_round++; + last_skipped = sbi->skipped_atomic_files[FG_GC]; + round++; + } + + if (gc_type == FG_GC) + sbi->cur_victim_sec = NULL_SEGNO; + + if (sync) + goto stop; + + if (has_not_enough_free_secs(sbi, sec_freed, 0)) { + if (skipped_round <= MAX_SKIP_GC_COUNT || + skipped_round * 2 < round) { + segno = NULL_SEGNO; + goto gc_more; + } + + if (first_skipped < last_skipped && + (last_skipped - first_skipped) > + sbi->skipped_gc_rwsem) { + 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) + 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 (f2fs_is_multi_device(sbi) && sbi->segs_per_sec == 1) + SIT_I(sbi)->last_victim[ALLOC_NEXT] = + GET_SEGNO(sbi, FDEV(0).end_blk) + 1; +} |