x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 860 insertions, 0 deletions

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
new file mode 100644
index 000000000..ff379aff4
--- /dev/null
+++ b/fs/f2fs/debug.c
@@ -0,0 +1,860 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * f2fs debugging statistics
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *             http://www.samsung.com/
+ * Copyright (c) 2012 Linux Foundation
+ * Copyright (c) 2012 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ */
+
+#include <linux/fs.h>
+#include <linux/backing-dev.h>
+#include <linux/f2fs_fs.h>
+#include <linux/blkdev.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "f2fs.h"
+#include "node.h"
+#include "segment.h"
+#include "gc.h"
+
+static LIST_HEAD(f2fs_stat_list);
+static DEFINE_SPINLOCK(f2fs_stat_lock);
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *f2fs_debugfs_root;
+#endif
+
+/*
+ * This function calculates BDF of every segments
+ */
+void f2fs_update_sit_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	unsigned long long blks_per_sec, hblks_per_sec, total_vblocks;
+	unsigned long long bimodal, dist;
+	unsigned int segno, vblocks;
+	int ndirty = 0;
+
+	bimodal = 0;
+	total_vblocks = 0;
+	blks_per_sec = CAP_BLKS_PER_SEC(sbi);
+	hblks_per_sec = blks_per_sec / 2;
+	for (segno = 0; segno < MAIN_SEGS(sbi); segno += SEGS_PER_SEC(sbi)) {
+		vblocks = get_valid_blocks(sbi, segno, true);
+		dist = abs(vblocks - hblks_per_sec);
+		bimodal += dist * dist;
+
+		if (vblocks > 0 && vblocks < blks_per_sec) {
+			total_vblocks += vblocks;
+			ndirty++;
+		}
+	}
+	dist = div_u64(MAIN_SECS(sbi) * hblks_per_sec * hblks_per_sec, 100);
+	si->bimodal = div64_u64(bimodal, dist);
+	if (si->dirty_count)
+		si->avg_vblocks = div_u64(total_vblocks, ndirty);
+	else
+		si->avg_vblocks = 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void update_multidevice_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	struct f2fs_dev_stats *dev_stats = si->dev_stats;
+	int i, j;
+
+	if (!f2fs_is_multi_device(sbi))
+		return;
+
+	memset(dev_stats, 0, sizeof(struct f2fs_dev_stats) * sbi->s_ndevs);
+	for (i = 0; i < sbi->s_ndevs; i++) {
+		unsigned int start_segno, end_segno;
+		block_t start_blk, end_blk;
+
+		if (i == 0) {
+			start_blk = MAIN_BLKADDR(sbi);
+			end_blk = FDEV(i).end_blk + 1 - SEG0_BLKADDR(sbi);
+		} else {
+			start_blk = FDEV(i).start_blk;
+			end_blk = FDEV(i).end_blk + 1;
+		}
+
+		start_segno = GET_SEGNO(sbi, start_blk);
+		end_segno = GET_SEGNO(sbi, end_blk);
+
+		for (j = start_segno; j < end_segno; j++) {
+			unsigned int seg_blks, sec_blks;
+
+			seg_blks = get_seg_entry(sbi, j)->valid_blocks;
+
+			/* update segment stats */
+			if (is_curseg(sbi, j))
+				dev_stats[i].devstats[0][DEVSTAT_INUSE]++;
+			else if (seg_blks == BLKS_PER_SEG(sbi))
+				dev_stats[i].devstats[0][DEVSTAT_FULL]++;
+			else if (seg_blks != 0)
+				dev_stats[i].devstats[0][DEVSTAT_DIRTY]++;
+			else if (!test_bit(j, FREE_I(sbi)->free_segmap))
+				dev_stats[i].devstats[0][DEVSTAT_FREE]++;
+			else
+				dev_stats[i].devstats[0][DEVSTAT_PREFREE]++;
+
+			if (!__is_large_section(sbi) ||
+				(j % SEGS_PER_SEC(sbi)) != 0)
+				continue;
+
+			sec_blks = get_sec_entry(sbi, j)->valid_blocks;
+
+			/* update section stats */
+			if (is_cursec(sbi, GET_SEC_FROM_SEG(sbi, j)))
+				dev_stats[i].devstats[1][DEVSTAT_INUSE]++;
+			else if (sec_blks == BLKS_PER_SEC(sbi))
+				dev_stats[i].devstats[1][DEVSTAT_FULL]++;
+			else if (sec_blks != 0)
+				dev_stats[i].devstats[1][DEVSTAT_DIRTY]++;
+			else if (!test_bit(GET_SEC_FROM_SEG(sbi, j),
+					FREE_I(sbi)->free_secmap))
+				dev_stats[i].devstats[1][DEVSTAT_FREE]++;
+			else
+				dev_stats[i].devstats[1][DEVSTAT_PREFREE]++;
+		}
+	}
+}
+
+static void update_general_status(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	int i;
+
+	/* these will be changed if online resize is done */
+	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
+	si->main_area_sections = le32_to_cpu(raw_super->section_count);
+	si->main_area_zones = si->main_area_sections /
+				le32_to_cpu(raw_super->secs_per_zone);
+
+	/* general extent cache stats */
+	for (i = 0; i < NR_EXTENT_CACHES; i++) {
+		struct extent_tree_info *eti = &sbi->extent_tree[i];
+
+		si->hit_cached[i] = atomic64_read(&sbi->read_hit_cached[i]);
+		si->hit_rbtree[i] = atomic64_read(&sbi->read_hit_rbtree[i]);
+		si->total_ext[i] = atomic64_read(&sbi->total_hit_ext[i]);
+		si->hit_total[i] = si->hit_cached[i] + si->hit_rbtree[i];
+		si->ext_tree[i] = atomic_read(&eti->total_ext_tree);
+		si->zombie_tree[i] = atomic_read(&eti->total_zombie_tree);
+		si->ext_node[i] = atomic_read(&eti->total_ext_node);
+	}
+	/* read extent_cache only */
+	si->hit_largest = atomic64_read(&sbi->read_hit_largest);
+	si->hit_total[EX_READ] += si->hit_largest;
+
+	/* block age extent_cache only */
+	si->allocated_data_blocks = atomic64_read(&sbi->allocated_data_blocks);
+
+	/* validation check of the segment numbers */
+	si->ndirty_node = get_pages(sbi, F2FS_DIRTY_NODES);
+	si->ndirty_dent = get_pages(sbi, F2FS_DIRTY_DENTS);
+	si->ndirty_meta = get_pages(sbi, F2FS_DIRTY_META);
+	si->ndirty_data = get_pages(sbi, F2FS_DIRTY_DATA);
+	si->ndirty_qdata = get_pages(sbi, F2FS_DIRTY_QDATA);
+	si->ndirty_imeta = get_pages(sbi, F2FS_DIRTY_IMETA);
+	si->ndirty_dirs = sbi->ndirty_inode[DIR_INODE];
+	si->ndirty_files = sbi->ndirty_inode[FILE_INODE];
+	si->ndonate_files = sbi->donate_files;
+	si->nquota_files = sbi->nquota_files;
+	si->ndirty_all = sbi->ndirty_inode[DIRTY_META];
+	si->aw_cnt = atomic_read(&sbi->atomic_files);
+	si->max_aw_cnt = atomic_read(&sbi->max_aw_cnt);
+	si->nr_dio_read = get_pages(sbi, F2FS_DIO_READ);
+	si->nr_dio_write = get_pages(sbi, F2FS_DIO_WRITE);
+	si->nr_wb_cp_data = get_pages(sbi, F2FS_WB_CP_DATA);
+	si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA);
+	si->nr_rd_data = get_pages(sbi, F2FS_RD_DATA);
+	si->nr_rd_node = get_pages(sbi, F2FS_RD_NODE);
+	si->nr_rd_meta = get_pages(sbi, F2FS_RD_META);
+	if (SM_I(sbi)->fcc_info) {
+		si->nr_flushed =
+			atomic_read(&SM_I(sbi)->fcc_info->issued_flush);
+		si->nr_flushing =
+			atomic_read(&SM_I(sbi)->fcc_info->queued_flush);
+		si->flush_list_empty =
+			llist_empty(&SM_I(sbi)->fcc_info->issue_list);
+	}
+	if (SM_I(sbi)->dcc_info) {
+		si->nr_discarded =
+			atomic_read(&SM_I(sbi)->dcc_info->issued_discard);
+		si->nr_discarding =
+			atomic_read(&SM_I(sbi)->dcc_info->queued_discard);
+		si->nr_discard_cmd =
+			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
+		si->undiscard_blks = SM_I(sbi)->dcc_info->undiscard_blks;
+	}
+	si->nr_issued_ckpt = atomic_read(&sbi->cprc_info.issued_ckpt);
+	si->nr_total_ckpt = atomic_read(&sbi->cprc_info.total_ckpt);
+	si->nr_queued_ckpt = atomic_read(&sbi->cprc_info.queued_ckpt);
+	spin_lock(&sbi->cprc_info.stat_lock);
+	si->cur_ckpt_time = sbi->cprc_info.cur_time;
+	si->peak_ckpt_time = sbi->cprc_info.peak_time;
+	spin_unlock(&sbi->cprc_info.stat_lock);
+	si->total_count = BLKS_TO_SEGS(sbi, (int)sbi->user_block_count);
+	si->rsvd_segs = reserved_segments(sbi);
+	si->overp_segs = overprovision_segments(sbi);
+	si->valid_count = valid_user_blocks(sbi);
+	si->discard_blks = discard_blocks(sbi);
+	si->valid_node_count = valid_node_count(sbi);
+	si->valid_inode_count = valid_inode_count(sbi);
+	si->inline_xattr = atomic_read(&sbi->inline_xattr);
+	si->inline_inode = atomic_read(&sbi->inline_inode);
+	si->inline_dir = atomic_read(&sbi->inline_dir);
+	si->compr_inode = atomic_read(&sbi->compr_inode);
+	si->swapfile_inode = atomic_read(&sbi->swapfile_inode);
+	si->compr_blocks = atomic64_read(&sbi->compr_blocks);
+	si->append = sbi->im[APPEND_INO].ino_num;
+	si->update = sbi->im[UPDATE_INO].ino_num;
+	si->orphans = sbi->im[ORPHAN_INO].ino_num;
+	si->utilization = utilization(sbi);
+
+	si->free_segs = free_segments(sbi);
+	si->free_secs = free_sections(sbi);
+	si->prefree_count = prefree_segments(sbi);
+	si->dirty_count = dirty_segments(sbi);
+	if (sbi->node_inode)
+		si->node_pages = NODE_MAPPING(sbi)->nrpages;
+	if (sbi->meta_inode)
+		si->meta_pages = META_MAPPING(sbi)->nrpages;
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+	if (sbi->compress_inode) {
+		si->compress_pages = COMPRESS_MAPPING(sbi)->nrpages;
+		si->compress_page_hit = atomic_read(&sbi->compress_page_hit);
+	}
+#endif
+	si->nats = NM_I(sbi)->nat_cnt[TOTAL_NAT];
+	si->dirty_nats = NM_I(sbi)->nat_cnt[DIRTY_NAT];
+	si->sits = MAIN_SEGS(sbi);
+	si->dirty_sits = SIT_I(sbi)->dirty_sentries;
+	si->free_nids = NM_I(sbi)->nid_cnt[FREE_NID];
+	si->avail_nids = NM_I(sbi)->available_nids;
+	si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
+	si->io_skip_bggc = sbi->io_skip_bggc;
+	si->other_skip_bggc = sbi->other_skip_bggc;
+	si->util_free = (int)(BLKS_TO_SEGS(sbi, free_user_blocks(sbi)))
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_valid = (int)(BLKS_TO_SEGS(sbi, written_block_count(sbi)))
+		* 100 / (int)(sbi->user_block_count >> sbi->log_blocks_per_seg)
+		/ 2;
+	si->util_invalid = 50 - si->util_free - si->util_valid;
+	for (i = CURSEG_HOT_DATA; i < NO_CHECK_TYPE; i++) {
+		struct curseg_info *curseg = CURSEG_I(sbi, i);
+
+		si->blkoff[i] = curseg->next_blkoff;
+		si->curseg[i] = curseg->segno;
+		si->cursec[i] = GET_SEC_FROM_SEG(sbi, curseg->segno);
+		si->curzone[i] = GET_ZONE_FROM_SEC(sbi, si->cursec[i]);
+	}
+
+	for (i = META_CP; i < META_MAX; i++)
+		si->meta_count[i] = atomic_read(&sbi->meta_count[i]);
+
+	for (i = 0; i < NO_CHECK_TYPE; i++) {
+		si->dirty_seg[i] = 0;
+		si->full_seg[i] = 0;
+		si->valid_blks[i] = 0;
+	}
+
+	for (i = 0; i < MAIN_SEGS(sbi); i++) {
+		int blks = get_seg_entry(sbi, i)->valid_blocks;
+		int type = get_seg_entry(sbi, i)->type;
+
+		if (!blks)
+			continue;
+
+		if (blks == BLKS_PER_SEG(sbi))
+			si->full_seg[type]++;
+		else
+			si->dirty_seg[type]++;
+		si->valid_blks[type] += blks;
+	}
+
+	update_multidevice_stats(sbi);
+
+	for (i = 0; i < MAX_CALL_TYPE; i++)
+		si->cp_call_count[i] = atomic_read(&sbi->cp_call_count[i]);
+
+	for (i = 0; i < 2; i++) {
+		si->segment_count[i] = sbi->segment_count[i];
+		si->block_count[i] = sbi->block_count[i];
+	}
+
+	si->inplace_count = atomic_read(&sbi->inplace_count);
+}
+
+/*
+ * This function calculates memory footprint.
+ */
+static void update_mem_info(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+	int i;
+
+	if (si->base_mem)
+		goto get_cache;
+
+	/* build stat */
+	si->base_mem = sizeof(struct f2fs_stat_info);
+
+	/* build superblock */
+	si->base_mem += sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
+	si->base_mem += 2 * sizeof(struct f2fs_inode_info);
+	si->base_mem += sizeof(*sbi->ckpt);
+
+	/* build sm */
+	si->base_mem += sizeof(struct f2fs_sm_info);
+
+	/* build sit */
+	si->base_mem += sizeof(struct sit_info);
+	si->base_mem += MAIN_SEGS(sbi) * sizeof(struct seg_entry);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += 2 * SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
+	si->base_mem += SIT_VBLOCK_MAP_SIZE * MAIN_SEGS(sbi);
+	si->base_mem += SIT_VBLOCK_MAP_SIZE;
+	if (__is_large_section(sbi))
+		si->base_mem += MAIN_SECS(sbi) * sizeof(struct sec_entry);
+	si->base_mem += __bitmap_size(sbi, SIT_BITMAP);
+
+	/* build free segmap */
+	si->base_mem += sizeof(struct free_segmap_info);
+	si->base_mem += f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build curseg */
+	si->base_mem += sizeof(struct curseg_info) * NR_CURSEG_TYPE;
+	si->base_mem += PAGE_SIZE * NR_CURSEG_TYPE;
+
+	/* build dirty segmap */
+	si->base_mem += sizeof(struct dirty_seglist_info);
+	si->base_mem += NR_DIRTY_TYPE * f2fs_bitmap_size(MAIN_SEGS(sbi));
+	si->base_mem += f2fs_bitmap_size(MAIN_SECS(sbi));
+
+	/* build nm */
+	si->base_mem += sizeof(struct f2fs_nm_info);
+	si->base_mem += __bitmap_size(sbi, NAT_BITMAP);
+	si->base_mem += F2FS_BLK_TO_BYTES(NM_I(sbi)->nat_bits_blocks);
+	si->base_mem += NM_I(sbi)->nat_blocks *
+				f2fs_bitmap_size(NAT_ENTRY_PER_BLOCK);
+	si->base_mem += NM_I(sbi)->nat_blocks / 8;
+	si->base_mem += NM_I(sbi)->nat_blocks * sizeof(unsigned short);
+
+get_cache:
+	si->cache_mem = 0;
+
+	/* build merge flush thread */
+	if (SM_I(sbi)->fcc_info)
+		si->cache_mem += sizeof(struct flush_cmd_control);
+	if (SM_I(sbi)->dcc_info) {
+		si->cache_mem += sizeof(struct discard_cmd_control);
+		si->cache_mem += sizeof(struct discard_cmd) *
+			atomic_read(&SM_I(sbi)->dcc_info->discard_cmd_cnt);
+	}
+
+	/* free nids */
+	si->cache_mem += (NM_I(sbi)->nid_cnt[FREE_NID] +
+				NM_I(sbi)->nid_cnt[PREALLOC_NID]) *
+				sizeof(struct free_nid);
+	si->cache_mem += NM_I(sbi)->nat_cnt[TOTAL_NAT] *
+				sizeof(struct nat_entry);
+	si->cache_mem += NM_I(sbi)->nat_cnt[DIRTY_NAT] *
+				sizeof(struct nat_entry_set);
+	for (i = 0; i < MAX_INO_ENTRY; i++)
+		si->cache_mem += sbi->im[i].ino_num * sizeof(struct ino_entry);
+
+	for (i = 0; i < NR_EXTENT_CACHES; i++) {
+		struct extent_tree_info *eti = &sbi->extent_tree[i];
+
+		si->ext_mem[i] = atomic_read(&eti->total_ext_tree) *
+						sizeof(struct extent_tree);
+		si->ext_mem[i] += atomic_read(&eti->total_ext_node) *
+						sizeof(struct extent_node);
+		si->cache_mem += si->ext_mem[i];
+	}
+
+	si->page_mem = 0;
+	if (sbi->node_inode) {
+		unsigned long npages = NODE_MAPPING(sbi)->nrpages;
+
+		si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+	}
+	if (sbi->meta_inode) {
+		unsigned long npages = META_MAPPING(sbi)->nrpages;
+
+		si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+	}
+#ifdef CONFIG_F2FS_FS_COMPRESSION
+	if (sbi->compress_inode) {
+		unsigned long npages = COMPRESS_MAPPING(sbi)->nrpages;
+
+		si->page_mem += (unsigned long long)npages << PAGE_SHIFT;
+	}
+#endif
+}
+
+static const char *s_flag[MAX_SBI_FLAG] = {
+	[SBI_IS_DIRTY]		= "fs_dirty",
+	[SBI_IS_CLOSE]		= "closing",
+	[SBI_NEED_FSCK]		= "need_fsck",
+	[SBI_POR_DOING]		= "recovering",
+	[SBI_NEED_SB_WRITE]	= "sb_dirty",
+	[SBI_NEED_CP]		= "need_cp",
+	[SBI_IS_SHUTDOWN]	= "shutdown",
+	[SBI_IS_RECOVERED]	= "recovered",
+	[SBI_CP_DISABLED]	= "cp_disabled",
+	[SBI_CP_DISABLED_QUICK]	= "cp_disabled_quick",
+	[SBI_QUOTA_NEED_FLUSH]	= "quota_need_flush",
+	[SBI_QUOTA_SKIP_FLUSH]	= "quota_skip_flush",
+	[SBI_QUOTA_NEED_REPAIR]	= "quota_need_repair",
+	[SBI_IS_RESIZEFS]	= "resizefs",
+	[SBI_IS_FREEZING]	= "freezefs",
+	[SBI_IS_WRITABLE]	= "writable",
+	[SBI_ENABLE_CHECKPOINT]	= "enable_checkpoint",
+};
+
+static const char *ipu_mode_names[F2FS_IPU_MAX] = {
+	[F2FS_IPU_FORCE]	= "FORCE",
+	[F2FS_IPU_SSR]		= "SSR",
+	[F2FS_IPU_UTIL]		= "UTIL",
+	[F2FS_IPU_SSR_UTIL]	= "SSR_UTIL",
+	[F2FS_IPU_FSYNC]	= "FSYNC",
+	[F2FS_IPU_ASYNC]	= "ASYNC",
+	[F2FS_IPU_NOCACHE]	= "NOCACHE",
+	[F2FS_IPU_HONOR_OPU_WRITE]	= "HONOR_OPU_WRITE",
+};
+
+static int stat_show(struct seq_file *s, void *v)
+{
+	struct f2fs_stat_info *si;
+	int i = 0, j = 0;
+
+	spin_lock(&f2fs_stat_lock);
+	list_for_each_entry(si, &f2fs_stat_list, stat_list) {
+		struct f2fs_sb_info *sbi = si->sbi;
+
+		update_general_status(sbi);
+
+		seq_printf(s, "\n=====[ partition info(%pg). #%d, %s, CP: %s]=====\n",
+			sbi->sb->s_bdev, i++,
+			f2fs_readonly(sbi->sb) ? "RO" : "RW",
+			is_set_ckpt_flags(sbi, CP_DISABLED_FLAG) ?
+			"Disabled" : (f2fs_cp_error(sbi) ? "Error" : "Good"));
+		if (sbi->s_flag) {
+			seq_puts(s, "[SBI:");
+			for_each_set_bit(j, &sbi->s_flag, MAX_SBI_FLAG)
+				seq_printf(s, " %s", s_flag[j]);
+			seq_puts(s, "]\n");
+		}
+		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
+			   si->sit_area_segs, si->nat_area_segs);
+		seq_printf(s, "[SSA: %d] [MAIN: %d",
+			   si->ssa_area_segs, si->main_area_segs);
+		seq_printf(s, "(OverProv:%d Resv:%d)]\n\n",
+			   si->overp_segs, si->rsvd_segs);
+		seq_printf(s, "Current Time Sec: %llu / Mounted Time Sec: %llu\n\n",
+					ktime_get_boottime_seconds(),
+					SIT_I(sbi)->mounted_time);
+
+		seq_puts(s, "Policy:\n");
+		seq_puts(s, "  - IPU: [");
+		if (IS_F2FS_IPU_DISABLE(sbi)) {
+			seq_puts(s, " DISABLE");
+		} else {
+			unsigned long policy = SM_I(sbi)->ipu_policy;
+
+			for_each_set_bit(j, &policy, F2FS_IPU_MAX)
+				seq_printf(s, " %s", ipu_mode_names[j]);
+		}
+		seq_puts(s, " ]\n\n");
+
+		if (test_opt(sbi, DISCARD))
+			seq_printf(s, "Utilization: %u%% (%u valid blocks, %u discard blocks)\n",
+				si->utilization, si->valid_count, si->discard_blks);
+		else
+			seq_printf(s, "Utilization: %u%% (%u valid blocks)\n",
+				si->utilization, si->valid_count);
+
+		seq_printf(s, "  - Node: %u (Inode: %u, ",
+			   si->valid_node_count, si->valid_inode_count);
+		seq_printf(s, "Other: %u)\n  - Data: %u\n",
+			   si->valid_node_count - si->valid_inode_count,
+			   si->valid_count - si->valid_node_count);
+		seq_printf(s, "  - Inline_xattr Inode: %u\n",
+			   si->inline_xattr);
+		seq_printf(s, "  - Inline_data Inode: %u\n",
+			   si->inline_inode);
+		seq_printf(s, "  - Inline_dentry Inode: %u\n",
+			   si->inline_dir);
+		seq_printf(s, "  - Compressed Inode: %u, Blocks: %llu\n",
+			   si->compr_inode, si->compr_blocks);
+		seq_printf(s, "  - Swapfile Inode: %u\n",
+			   si->swapfile_inode);
+		seq_printf(s, "  - Donate Inode: %u\n",
+			   si->ndonate_files);
+		seq_printf(s, "  - Orphan/Append/Update Inode: %u, %u, %u\n",
+			   si->orphans, si->append, si->update);
+		seq_printf(s, "\nMain area: %d segs, %d secs %d zones\n",
+			   si->main_area_segs, si->main_area_sections,
+			   si->main_area_zones);
+		seq_printf(s, "    TYPE         %8s %8s %8s %8s %10s %10s %10s\n",
+			   "blkoff", "segno", "secno", "zoneno", "dirty_seg", "full_seg", "valid_blk");
+		seq_printf(s, "  - COLD   data: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_COLD_DATA],
+			   si->curseg[CURSEG_COLD_DATA],
+			   si->cursec[CURSEG_COLD_DATA],
+			   si->curzone[CURSEG_COLD_DATA],
+			   si->dirty_seg[CURSEG_COLD_DATA],
+			   si->full_seg[CURSEG_COLD_DATA],
+			   si->valid_blks[CURSEG_COLD_DATA]);
+		seq_printf(s, "  - WARM   data: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_WARM_DATA],
+			   si->curseg[CURSEG_WARM_DATA],
+			   si->cursec[CURSEG_WARM_DATA],
+			   si->curzone[CURSEG_WARM_DATA],
+			   si->dirty_seg[CURSEG_WARM_DATA],
+			   si->full_seg[CURSEG_WARM_DATA],
+			   si->valid_blks[CURSEG_WARM_DATA]);
+		seq_printf(s, "  - HOT    data: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_HOT_DATA],
+			   si->curseg[CURSEG_HOT_DATA],
+			   si->cursec[CURSEG_HOT_DATA],
+			   si->curzone[CURSEG_HOT_DATA],
+			   si->dirty_seg[CURSEG_HOT_DATA],
+			   si->full_seg[CURSEG_HOT_DATA],
+			   si->valid_blks[CURSEG_HOT_DATA]);
+		seq_printf(s, "  - Dir   dnode: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_HOT_NODE],
+			   si->curseg[CURSEG_HOT_NODE],
+			   si->cursec[CURSEG_HOT_NODE],
+			   si->curzone[CURSEG_HOT_NODE],
+			   si->dirty_seg[CURSEG_HOT_NODE],
+			   si->full_seg[CURSEG_HOT_NODE],
+			   si->valid_blks[CURSEG_HOT_NODE]);
+		seq_printf(s, "  - File  dnode: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_WARM_NODE],
+			   si->curseg[CURSEG_WARM_NODE],
+			   si->cursec[CURSEG_WARM_NODE],
+			   si->curzone[CURSEG_WARM_NODE],
+			   si->dirty_seg[CURSEG_WARM_NODE],
+			   si->full_seg[CURSEG_WARM_NODE],
+			   si->valid_blks[CURSEG_WARM_NODE]);
+		seq_printf(s, "  - Indir nodes: %8d %8d %8d %8d %10u %10u %10u\n",
+			   si->blkoff[CURSEG_COLD_NODE],
+			   si->curseg[CURSEG_COLD_NODE],
+			   si->cursec[CURSEG_COLD_NODE],
+			   si->curzone[CURSEG_COLD_NODE],
+			   si->dirty_seg[CURSEG_COLD_NODE],
+			   si->full_seg[CURSEG_COLD_NODE],
+			   si->valid_blks[CURSEG_COLD_NODE]);
+		seq_printf(s, "  - Pinned file: %8d %8d %8d %8d\n",
+			   si->blkoff[CURSEG_COLD_DATA_PINNED],
+			   si->curseg[CURSEG_COLD_DATA_PINNED],
+			   si->cursec[CURSEG_COLD_DATA_PINNED],
+			   si->curzone[CURSEG_COLD_DATA_PINNED]);
+		seq_printf(s, "  - ATGC   data: %8d %8d %8d %8d\n",
+			   si->blkoff[CURSEG_ALL_DATA_ATGC],
+			   si->curseg[CURSEG_ALL_DATA_ATGC],
+			   si->cursec[CURSEG_ALL_DATA_ATGC],
+			   si->curzone[CURSEG_ALL_DATA_ATGC]);
+		seq_printf(s, "\n  - Valid: %d\n  - Dirty: %d\n",
+			   si->main_area_segs - si->dirty_count -
+			   si->prefree_count - si->free_segs,
+			   si->dirty_count);
+		seq_printf(s, "  - Prefree: %d\n  - Free: %d (%d)\n\n",
+			   si->prefree_count, si->free_segs, si->free_secs);
+		if (f2fs_is_multi_device(sbi)) {
+			seq_puts(s, "Multidevice stats:\n");
+			seq_printf(s, "  [seg:   %8s %8s %8s %8s %8s]",
+					"inuse", "dirty", "full", "free", "prefree");
+			if (__is_large_section(sbi))
+				seq_printf(s, " [sec:   %8s %8s %8s %8s %8s]\n",
+					"inuse", "dirty", "full", "free", "prefree");
+			else
+				seq_puts(s, "\n");
+
+			for (i = 0; i < sbi->s_ndevs; i++) {
+				seq_printf(s, "  #%-2d     %8u %8u %8u %8u %8u", i,
+					si->dev_stats[i].devstats[0][DEVSTAT_INUSE],
+					si->dev_stats[i].devstats[0][DEVSTAT_DIRTY],
+					si->dev_stats[i].devstats[0][DEVSTAT_FULL],
+					si->dev_stats[i].devstats[0][DEVSTAT_FREE],
+					si->dev_stats[i].devstats[0][DEVSTAT_PREFREE]);
+				if (!__is_large_section(sbi)) {
+					seq_puts(s, "\n");
+					continue;
+				}
+				seq_printf(s, "          %8u %8u %8u %8u %8u\n",
+					si->dev_stats[i].devstats[1][DEVSTAT_INUSE],
+					si->dev_stats[i].devstats[1][DEVSTAT_DIRTY],
+					si->dev_stats[i].devstats[1][DEVSTAT_FULL],
+					si->dev_stats[i].devstats[1][DEVSTAT_FREE],
+					si->dev_stats[i].devstats[1][DEVSTAT_PREFREE]);
+			}
+			seq_puts(s, "\n");
+		}
+		seq_printf(s, "CP calls: %d (BG: %d)\n",
+			   si->cp_call_count[TOTAL_CALL],
+			   si->cp_call_count[BACKGROUND]);
+		seq_printf(s, "CP count: %d\n", si->cp_count);
+		seq_printf(s, "  - cp blocks : %u\n", si->meta_count[META_CP]);
+		seq_printf(s, "  - sit blocks : %u\n",
+				si->meta_count[META_SIT]);
+		seq_printf(s, "  - nat blocks : %u\n",
+				si->meta_count[META_NAT]);
+		seq_printf(s, "  - ssa blocks : %u\n",
+				si->meta_count[META_SSA]);
+		seq_puts(s, "CP merge:\n");
+		seq_printf(s, "  - Queued : %4d\n", si->nr_queued_ckpt);
+		seq_printf(s, "  - Issued : %4d\n", si->nr_issued_ckpt);
+		seq_printf(s, "  - Total : %4d\n", si->nr_total_ckpt);
+		seq_printf(s, "  - Cur time : %4d(ms)\n", si->cur_ckpt_time);
+		seq_printf(s, "  - Peak time : %4d(ms)\n", si->peak_ckpt_time);
+		seq_printf(s, "GC calls: %d (gc_thread: %d)\n",
+			   si->gc_call_count[BACKGROUND] +
+			   si->gc_call_count[FOREGROUND],
+			   si->gc_call_count[BACKGROUND]);
+		if (__is_large_section(sbi)) {
+			seq_printf(s, "  - data sections : %d (BG: %d)\n",
+					si->gc_secs[DATA][BG_GC] + si->gc_secs[DATA][FG_GC],
+					si->gc_secs[DATA][BG_GC]);
+			seq_printf(s, "  - node sections : %d (BG: %d)\n",
+					si->gc_secs[NODE][BG_GC] + si->gc_secs[NODE][FG_GC],
+					si->gc_secs[NODE][BG_GC]);
+		}
+		seq_printf(s, "  - data segments : %d (BG: %d)\n",
+				si->gc_segs[DATA][BG_GC] + si->gc_segs[DATA][FG_GC],
+				si->gc_segs[DATA][BG_GC]);
+		seq_printf(s, "  - node segments : %d (BG: %d)\n",
+				si->gc_segs[NODE][BG_GC] + si->gc_segs[NODE][FG_GC],
+				si->gc_segs[NODE][BG_GC]);
+		seq_puts(s, "  - Reclaimed segs :\n");
+		seq_printf(s, "    - Normal : %d\n", sbi->gc_reclaimed_segs[GC_NORMAL]);
+		seq_printf(s, "    - Idle CB : %d\n", sbi->gc_reclaimed_segs[GC_IDLE_CB]);
+		seq_printf(s, "    - Idle Greedy : %d\n",
+				sbi->gc_reclaimed_segs[GC_IDLE_GREEDY]);
+		seq_printf(s, "    - Idle AT : %d\n", sbi->gc_reclaimed_segs[GC_IDLE_AT]);
+		seq_printf(s, "    - Urgent High : %d\n",
+				sbi->gc_reclaimed_segs[GC_URGENT_HIGH]);
+		seq_printf(s, "    - Urgent Mid : %d\n", sbi->gc_reclaimed_segs[GC_URGENT_MID]);
+		seq_printf(s, "    - Urgent Low : %d\n", sbi->gc_reclaimed_segs[GC_URGENT_LOW]);
+		seq_printf(s, "Try to move %d blocks (BG: %d)\n", si->tot_blks,
+				si->bg_data_blks + si->bg_node_blks);
+		seq_printf(s, "  - data blocks : %d (%d)\n", si->data_blks,
+				si->bg_data_blks);
+		seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
+				si->bg_node_blks);
+		seq_printf(s, "BG skip : IO: %u, Other: %u\n",
+				si->io_skip_bggc, si->other_skip_bggc);
+		seq_printf(s, "defrag blocks : %u\n", si->defrag_blks);
+		seq_puts(s, "\nExtent Cache (Read):\n");
+		seq_printf(s, "  - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n",
+				si->hit_largest, si->hit_cached[EX_READ],
+				si->hit_rbtree[EX_READ]);
+		seq_printf(s, "  - Hit Ratio: %llu%% (%llu / %llu)\n",
+				!si->total_ext[EX_READ] ? 0 :
+				div64_u64(si->hit_total[EX_READ] * 100,
+				si->total_ext[EX_READ]),
+				si->hit_total[EX_READ], si->total_ext[EX_READ]);
+		seq_printf(s, "  - Inner Struct Count: tree: %d(%d), node: %d\n",
+				si->ext_tree[EX_READ], si->zombie_tree[EX_READ],
+				si->ext_node[EX_READ]);
+		seq_puts(s, "\nExtent Cache (Block Age):\n");
+		seq_printf(s, "  - Allocated Data Blocks: %llu\n",
+				si->allocated_data_blocks);
+		seq_printf(s, "  - Hit Count: L1:%llu L2:%llu\n",
+				si->hit_cached[EX_BLOCK_AGE],
+				si->hit_rbtree[EX_BLOCK_AGE]);
+		seq_printf(s, "  - Hit Ratio: %llu%% (%llu / %llu)\n",
+				!si->total_ext[EX_BLOCK_AGE] ? 0 :
+				div64_u64(si->hit_total[EX_BLOCK_AGE] * 100,
+				si->total_ext[EX_BLOCK_AGE]),
+				si->hit_total[EX_BLOCK_AGE],
+				si->total_ext[EX_BLOCK_AGE]);
+		seq_printf(s, "  - Inner Struct Count: tree: %d(%d), node: %d\n",
+				si->ext_tree[EX_BLOCK_AGE],
+				si->zombie_tree[EX_BLOCK_AGE],
+				si->ext_node[EX_BLOCK_AGE]);
+		seq_puts(s, "\nBalancing F2FS Async:\n");
+		seq_printf(s, "  - DIO (R: %4d, W: %4d)\n",
+			   si->nr_dio_read, si->nr_dio_write);
+		seq_printf(s, "  - IO_R (Data: %4d, Node: %4d, Meta: %4d\n",
+			   si->nr_rd_data, si->nr_rd_node, si->nr_rd_meta);
+		seq_printf(s, "  - IO_W (CP: %4d, Data: %4d, Flush: (%4d %4d %4d), ",
+			   si->nr_wb_cp_data, si->nr_wb_data,
+			   si->nr_flushing, si->nr_flushed,
+			   si->flush_list_empty);
+		seq_printf(s, "Discard: (%4d %4d)) cmd: %4d undiscard:%4u\n",
+			   si->nr_discarding, si->nr_discarded,
+			   si->nr_discard_cmd, si->undiscard_blks);
+		seq_printf(s, "  - atomic IO: %4d (Max. %4d)\n",
+			   si->aw_cnt, si->max_aw_cnt);
+		seq_printf(s, "  - compress: %4d, hit:%8d\n", si->compress_pages, si->compress_page_hit);
+		seq_printf(s, "  - nodes: %4d in %4d\n",
+			   si->ndirty_node, si->node_pages);
+		seq_printf(s, "  - dents: %4d in dirs:%4d (%4d)\n",
+			   si->ndirty_dent, si->ndirty_dirs, si->ndirty_all);
+		seq_printf(s, "  - data: %4d in files:%4d\n",
+			   si->ndirty_data, si->ndirty_files);
+		seq_printf(s, "  - quota data: %4d in quota files:%4d\n",
+			   si->ndirty_qdata, si->nquota_files);
+		seq_printf(s, "  - meta: %4d in %4d\n",
+			   si->ndirty_meta, si->meta_pages);
+		seq_printf(s, "  - imeta: %4d\n",
+			   si->ndirty_imeta);
+		seq_printf(s, "  - fsync mark: %4lld\n",
+			   percpu_counter_sum_positive(
+					&sbi->rf_node_block_count));
+		seq_printf(s, "  - NATs: %9d/%9d\n  - SITs: %9d/%9d\n",
+			   si->dirty_nats, si->nats, si->dirty_sits, si->sits);
+		seq_printf(s, "  - free_nids: %9d/%9d\n  - alloc_nids: %9d\n",
+			   si->free_nids, si->avail_nids, si->alloc_nids);
+		seq_puts(s, "\nDistribution of User Blocks:");
+		seq_puts(s, " [ valid | invalid | free ]\n");
+		seq_puts(s, "  [");
+
+		for (j = 0; j < si->util_valid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_invalid; j++)
+			seq_putc(s, '-');
+		seq_putc(s, '|');
+
+		for (j = 0; j < si->util_free; j++)
+			seq_putc(s, '-');
+		seq_puts(s, "]\n\n");
+		seq_printf(s, "IPU: %u blocks\n", si->inplace_count);
+		seq_printf(s, "SSR: %u blocks in %u segments\n",
+			   si->block_count[SSR], si->segment_count[SSR]);
+		seq_printf(s, "LFS: %u blocks in %u segments\n",
+			   si->block_count[LFS], si->segment_count[LFS]);
+
+		/* segment usage info */
+		f2fs_update_sit_info(sbi);
+		seq_printf(s, "\nBDF: %u, avg. vblocks: %u\n",
+			   si->bimodal, si->avg_vblocks);
+
+		/* memory footprint */
+		update_mem_info(sbi);
+		seq_printf(s, "\nMemory: %llu KB\n",
+			(si->base_mem + si->cache_mem + si->page_mem) >> 10);
+		seq_printf(s, "  - static: %llu KB\n",
+				si->base_mem >> 10);
+		seq_printf(s, "  - cached all: %llu KB\n",
+				si->cache_mem >> 10);
+		seq_printf(s, "  - read extent cache: %llu KB\n",
+				si->ext_mem[EX_READ] >> 10);
+		seq_printf(s, "  - block age extent cache: %llu KB\n",
+				si->ext_mem[EX_BLOCK_AGE] >> 10);
+		seq_printf(s, "  - paged : %llu KB\n",
+				si->page_mem >> 10);
+	}
+	spin_unlock(&f2fs_stat_lock);
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(stat);
+#endif
+
+int f2fs_build_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
+	struct f2fs_stat_info *si;
+	struct f2fs_dev_stats *dev_stats;
+	int i;
+
+	si = f2fs_kzalloc(sbi, sizeof(struct f2fs_stat_info), GFP_KERNEL);
+	if (!si)
+		return -ENOMEM;
+
+	dev_stats = f2fs_kzalloc(sbi, sizeof(struct f2fs_dev_stats) *
+						sbi->s_ndevs, GFP_KERNEL);
+	if (!dev_stats) {
+		kfree(si);
+		return -ENOMEM;
+	}
+
+	si->dev_stats = dev_stats;
+
+	si->all_area_segs = le32_to_cpu(raw_super->segment_count);
+	si->sit_area_segs = le32_to_cpu(raw_super->segment_count_sit);
+	si->nat_area_segs = le32_to_cpu(raw_super->segment_count_nat);
+	si->ssa_area_segs = le32_to_cpu(raw_super->segment_count_ssa);
+	si->main_area_segs = le32_to_cpu(raw_super->segment_count_main);
+	si->main_area_sections = le32_to_cpu(raw_super->section_count);
+	si->main_area_zones = si->main_area_sections /
+				le32_to_cpu(raw_super->secs_per_zone);
+	si->sbi = sbi;
+	sbi->stat_info = si;
+
+	/* general extent cache stats */
+	for (i = 0; i < NR_EXTENT_CACHES; i++) {
+		atomic64_set(&sbi->total_hit_ext[i], 0);
+		atomic64_set(&sbi->read_hit_rbtree[i], 0);
+		atomic64_set(&sbi->read_hit_cached[i], 0);
+	}
+
+	/* read extent_cache only */
+	atomic64_set(&sbi->read_hit_largest, 0);
+
+	atomic_set(&sbi->inline_xattr, 0);
+	atomic_set(&sbi->inline_inode, 0);
+	atomic_set(&sbi->inline_dir, 0);
+	atomic_set(&sbi->compr_inode, 0);
+	atomic64_set(&sbi->compr_blocks, 0);
+	atomic_set(&sbi->swapfile_inode, 0);
+	atomic_set(&sbi->atomic_files, 0);
+	atomic_set(&sbi->inplace_count, 0);
+	for (i = META_CP; i < META_MAX; i++)
+		atomic_set(&sbi->meta_count[i], 0);
+	for (i = 0; i < MAX_CALL_TYPE; i++)
+		atomic_set(&sbi->cp_call_count[i], 0);
+
+	atomic_set(&sbi->max_aw_cnt, 0);
+
+	spin_lock(&f2fs_stat_lock);
+	list_add_tail(&si->stat_list, &f2fs_stat_list);
+	spin_unlock(&f2fs_stat_lock);
+
+	return 0;
+}
+
+void f2fs_destroy_stats(struct f2fs_sb_info *sbi)
+{
+	struct f2fs_stat_info *si = F2FS_STAT(sbi);
+
+	spin_lock(&f2fs_stat_lock);
+	list_del(&si->stat_list);
+	spin_unlock(&f2fs_stat_lock);
+
+	kfree(si->dev_stats);
+	kfree(si);
+}
+
+void __init f2fs_create_root_stats(void)
+{
+#ifdef CONFIG_DEBUG_FS
+	f2fs_debugfs_root = debugfs_create_dir("f2fs", NULL);
+
+	debugfs_create_file("status", 0444, f2fs_debugfs_root, NULL,
+			    &stat_fops);
+#endif
+}
+
+void f2fs_destroy_root_stats(void)
+{
+#ifdef CONFIG_DEBUG_FS
+	debugfs_remove_recursive(f2fs_debugfs_root);
+	f2fs_debugfs_root = NULL;
+#endif
+}