v4.19.13 snapshot.
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
new file mode 100644
index 0000000..5c8d004
--- /dev/null
+++ b/fs/f2fs/gc.c
@@ -0,0 +1,1262 @@
+/*
+ * 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 (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;
+ 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);
+ }
+
+ *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 = -EFAULT;
+ 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]))
+ 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 ||
+ !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);
+
+ 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 = 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;
+}