f2fs: introduce SEGS_TO_BLKS/BLKS_TO_SEGS for cleanup

Just cleanup, no functional change.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check number of blocks in a current section

In cfd66bb715fd ("f2fs: fix deadloop in foreground GC"), we needed to check
the number of blocks in a section instead of the segment.

Fixes: cfd66bb715fd ("f2fs: fix deadloop in foreground GC")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support file pinning for zoned devices

Support file pinning with conventional storage area for zoned devices

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: kill heap-based allocation

No one uses this feature. Let's kill it.

Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use BLKS_PER_SEG, BLKS_PER_SEC, and SEGS_PER_SEC

No functional change.

Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Clean up errors in segment.h

Fix the following errors reported by checkpatch:

ERROR: spaces required around that ':' (ctx:VxW)

Signed-off-by: KaiLong Wang <wangkailong@jari.cn>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add has_enough_free_secs()

Replace !has_not_enough_free_secs w/ has_enough_free_secs.
BTW avoid nested 'if' statements in f2fs_balance_fs().

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix system crash due to lack of free space in LFS

When f2fs tries to checkpoint during foreground gc in LFS mode, system
crash occurs due to lack of free space if the amount of dirty node and
dentry pages generated by data migration exceeds free space.
The reproduction sequence is as follows.

- 20GiB capacity block device (null_blk)
- format and mount with LFS mode
- create a file and write 20,000MiB
- 4k random write on full range of the file

RIP: 0010:new_curseg+0x48a/0x510 [f2fs]
Code: 55 e7 f5 89 c0 48 0f af c3 48 8b 5d c0 48 c1 e8 20 83 c0 01 89 43 6c 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc <0f> 0b f0 41 80 4f 48 04 45 85 f6 0f 84 ba fd ff ff e9 ef fe ff ff
RSP: 0018:ffff977bc397b218 EFLAGS: 00010246
RAX: 00000000000027b9 RBX: 0000000000000000 RCX: 00000000000027c0
RDX: 0000000000000000 RSI: 00000000000027b9 RDI: ffff8c25ab4e74f8
RBP: ffff977bc397b268 R08: 00000000000027b9 R09: ffff8c29e4a34b40
R10: 0000000000000001 R11: ffff977bc397b0d8 R12: 0000000000000000
R13: ffff8c25b4dd81a0 R14: 0000000000000000 R15: ffff8c2f667f9000
FS: 0000000000000000(0000) GS:ffff8c344ec80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00055d000 CR3: 0000000e30810003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
allocate_segment_by_default+0x9c/0x110 [f2fs]
f2fs_allocate_data_block+0x243/0xa30 [f2fs]
? __mod_lruvec_page_state+0xa0/0x150
do_write_page+0x80/0x160 [f2fs]
f2fs_do_write_node_page+0x32/0x50 [f2fs]
__write_node_page+0x339/0x730 [f2fs]
f2fs_sync_node_pages+0x5a6/0x780 [f2fs]
block_operations+0x257/0x340 [f2fs]
f2fs_write_checkpoint+0x102/0x1050 [f2fs]
f2fs_gc+0x27c/0x630 [f2fs]
? folio_mark_dirty+0x36/0x70
f2fs_balance_fs+0x16f/0x180 [f2fs]

This patch adds checking whether free sections are enough before checkpoint
during gc.

Signed-off-by: Yonggil Song <yonggil.song@samsung.com>
[Jaegeuk Kim: code clean-up]
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove struct victim_selection default_v_ops

There is only single instance of these ops, and Jaegeuk point out that:

Originally this was intended to give a chance to provide other
allocation option. Anyway, it seems quit hard to do it anymore.

So remove the indirection and call f2fs_get_victim() directly.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: apply zone capacity to all zone type

If we manage the zone capacity per zone type, it'll break the GC assumption.
And, the current logic complains valid block count mismatch.
Let's apply zone capacity to all zone type, if specified.

Fixes: de881df97768 ("f2fs: support zone capacity less than zone size")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix wrong segment count

MAIN_SEGS is for data area, while TOTAL_SEGS includes data and metadata.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: export ipu policy in debugfs

Export ipu_policy as a string in debugfs for better readability and
it can help us better understand some strategies of the file system.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to set ipu policy

For LFS mode, it should update outplace and no need inplace update.
When using LFS mode for small-volume devices, IPU will not be used,
and the OPU writing method is actually used, but F2FS_IPU_FORCE can
be read from the ipu_policy node, which is different from the actual
situation. And remount to lfs mode should be disallowed when
f2fs ipu is enabled, let's fix it.

Fixes: 84b89e5d943d ("f2fs: add auto tuning for small devices")
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add a f2fs_curseg_valid_blocks helper

Add a helper to return the valid blocks on log and SSR segments, and
replace the last two uses of curseg_blkoff with it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: convert discard_wake and gc_wake to bool type

discard_wake and gc_wake have only two values, 0 or 1.
So there is no need to use int type to store them.

BTW, move discard_wake to the end of the
discard_cmd_control structure.

Before:

- sizeof(struct discard_cmd_control): 8392

After move:

- sizeof(struct discard_cmd_control): 8384

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce IS_F2FS_IPU_* macro

IS_F2FS_IPU_* macro can be used to identify whether
f2fs ipu related policies are enabled.

BTW, convert to use BIT() instead of open code.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove struct segment_allocation default_salloc_ops

There is only single instance of these ops, so remove the indirection
and call allocate_segment_by_default directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support recording errors into superblock

This patch supports to record detail reason of FSCORRUPTED error into
f2fs_super_block.s_errors[].

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: adjust zone capacity when considering valid block count

This patch fixes counting unusable blocks set by zone capacity when
checking the valid block count in a section.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enforce single zone capacity

In order to simplify the complicated per-zone capacity, let's support
only one capacity for entire zoned device.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change the current atomic write way

Current atomic write has three major issues like below.
- keeps the updates in non-reclaimable memory space and they are even
hard to be migrated, which is not good for contiguous memory
allocation.
- disk spaces used for atomic files cannot be garbage collected, so
this makes it difficult for the filesystem to be defragmented.
- If atomic write operations hit the threshold of either memory usage
or garbage collection failure count, All the atomic write operations
will fail immediately.

To resolve the issues, I will keep a COW inode internally for all the
updates to be flushed from memory, when we need to flush them out in a
situation like high memory pressure. These COW inodes will be tagged
as orphan inodes to be reclaimed in case of sudden power-cut or system
failure during atomic writes.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: give priority to select unpinned section for foreground GC

Previously, during foreground GC, if victims contain data of pinned file,
it will fail migration of the data, and meanwhile i_gc_failures of that
pinned file may increase, and when it exceeds threshold, GC will unpin
the file, result in breaking pinfile's semantics.

In order to mitigate such condition, let's record and skip section which
has pinned file's data and give priority to select unpinned one.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check on total_data_blocks

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215916

The kernel message is shown below:

kernel BUG at fs/f2fs/segment.c:2560!
Call Trace:
allocate_segment_by_default+0x228/0x440
f2fs_allocate_data_block+0x13d1/0x31f0
do_write_page+0x18d/0x710
f2fs_outplace_write_data+0x151/0x250
f2fs_do_write_data_page+0xef9/0x1980
move_data_page+0x6af/0xbc0
do_garbage_collect+0x312f/0x46f0
f2fs_gc+0x6b0/0x3bc0
f2fs_balance_fs+0x921/0x2260
f2fs_write_single_data_page+0x16be/0x2370
f2fs_write_cache_pages+0x428/0xd00
f2fs_write_data_pages+0x96e/0xd50
do_writepages+0x168/0x550
__writeback_single_inode+0x9f/0x870
writeback_sb_inodes+0x47d/0xb20
__writeback_inodes_wb+0xb2/0x200
wb_writeback+0x4bd/0x660
wb_workfn+0x5f3/0xab0
process_one_work+0x79f/0x13e0
worker_thread+0x89/0xf60
kthread+0x26a/0x300
ret_from_fork+0x22/0x30
RIP: 0010:new_curseg+0xe8d/0x15f0

The root cause is: ckpt.valid_block_count is inconsistent with SIT table,
stat info indicates filesystem has free blocks, but SIT table indicates
filesystem has no free segment.

So that during garbage colloection, it triggers panic when LFS allocator
fails to find free segment.

This patch tries to fix this issue by checking consistency in between
ckpt.valid_block_count and block accounted from SIT.

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix deadloop in foreground GC

As Yanming reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=215914

The root cause is: in a very small sized image, it's very easy to
exceed threshold of foreground GC, if we calculate free space and
dirty data based on section granularity, in corner case,
has_not_enough_free_secs() will always return true, result in
deadloop in f2fs_gc().

So this patch refactors has_not_enough_free_secs() as below to fix
this issue:
1. calculate needed space based on block granularity, and separate
all blocks to two parts, section part, and block part, comparing
section part to free section, and comparing block part to free space
in openned log.
2. account F2FS_DIRTY_NODES, F2FS_DIRTY_IMETA and F2FS_DIRTY_DENTS
as node block consumer;
3. account F2FS_DIRTY_DENTS as data block consumer;

Cc: stable@vger.kernel.org
Reported-by: Ming Yan <yanming@tju.edu.cn>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce F2FS_IPU_HONOR_OPU_WRITE ipu policy

Once F2FS_IPU_FORCE policy is enabled in some cases:
a) f2fs forces to use F2FS_IPU_FORCE in a small-sized volume
b) user sets F2FS_IPU_FORCE policy via sysfs

Then we may fail to defragment file due to IPU policy check, it doesn't
make sense, let's introduce a new IPU policy to allow OPU during file
defragmentation.

In small-sized volume, let's enable F2FS_IPU_HONOR_OPU_WRITE policy
by default.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to reserve space for IO align feature

https://bugzilla.kernel.org/show_bug.cgi?id=204137

With below script, we will hit panic during new segment allocation:

DISK=bingo.img
MOUNT_DIR=/mnt/f2fs

dd if=/dev/zero of=$DISK bs=1M count=105
mkfs.f2fe -a 1 -o 19 -t 1 -z 1 -f -q $DISK

mount -t f2fs $DISK $MOUNT_DIR -o "noinline_dentry,flush_merge,noextent_cache,mode=lfs,io_bits=7,fsync_mode=strict"

for (( i = 0; i < 4096; i++ )); do
name=`head /dev/urandom | tr -dc A-Za-z0-9 | head -c 10`
mkdir $MOUNT_DIR/$name
done

umount $MOUNT_DIR
rm $DISK

--- Core dump ---
Call Trace:
allocate_segment_by_default+0x9d/0x100 [f2fs]
f2fs_allocate_data_block+0x3c0/0x5c0 [f2fs]
do_write_page+0x62/0x110 [f2fs]
f2fs_outplace_write_data+0x43/0xc0 [f2fs]
f2fs_do_write_data_page+0x386/0x560 [f2fs]
__write_data_page+0x706/0x850 [f2fs]
f2fs_write_cache_pages+0x267/0x6a0 [f2fs]
f2fs_write_data_pages+0x19c/0x2e0 [f2fs]
do_writepages+0x1c/0x70
__filemap_fdatawrite_range+0xaa/0xe0
filemap_fdatawrite+0x1f/0x30
f2fs_sync_dirty_inodes+0x74/0x1f0 [f2fs]
block_operations+0xdc/0x350 [f2fs]
f2fs_write_checkpoint+0x104/0x1150 [f2fs]
f2fs_sync_fs+0xa2/0x120 [f2fs]
f2fs_balance_fs_bg+0x33c/0x390 [f2fs]
f2fs_write_node_pages+0x4c/0x1f0 [f2fs]
do_writepages+0x1c/0x70
__writeback_single_inode+0x45/0x320
writeback_sb_inodes+0x273/0x5c0
wb_writeback+0xff/0x2e0
wb_workfn+0xa1/0x370
process_one_work+0x138/0x350
worker_thread+0x4d/0x3d0
kthread+0x109/0x140
ret_from_fork+0x25/0x30

The root cause here is, with IO alignment feature enables, in worst
case, we need F2FS_IO_SIZE() free blocks space for single one 4k write
due to IO alignment feature will fill dummy pages to make IO being
aligned.

So we will easily run out of free segments during non-inline directory's
data writeback, even in process of foreground GC.

In order to fix this issue, I just propose to reserve additional free
space for IO alignment feature to handle worst case of free space usage
ratio during FGGC.

Fixes: 0a595ebaaa6b ("f2fs: support IO alignment for DATA and NODE writes")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce fragment allocation mode mount option

Added two options into "mode=" mount option to make it possible for
developers to simulate filesystem fragmentation/after-GC situation
itself. The developers use these modes to understand filesystem
fragmentation/after-GC condition well, and eventually get some
insights to handle them better.

"fragment:segment": f2fs allocates a new segment in ramdom position.
With this, we can simulate the after-GC condition.
"fragment:block" : We can scatter block allocation with
"max_fragment_chunk" and "max_fragment_hole" sysfs
nodes. f2fs will allocate 1..<max_fragment_chunk>
blocks in a chunk and make a hole in the length of
1..<max_fragment_hole> by turns in a newly allocated
free segment. Plus, this mode implicitly enables
"fragment:segment" option for more randomness.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: correct comment in segment.h

s/two/three

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid touching checkpointed data in get_victim()

In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR
mode to select victim:

1. LFS is set to find source section during GC, the victim should have
no checkpointed data, since after GC, section could not be set free for
reuse.

Previously, we only check valid chpt blocks in current segment rather
than section, fix it.

2. SSR | AT_SSR are set to find target segment for writes which can be
fully filled by checkpointed and newly written blocks, we should never
select such segment, otherwise it can cause panic or data corruption
during allocation, potential case is described as below:

a) target segment has 'n' (n < 512) ckpt valid blocks
b) GC migrates 'n' valid blocks to other segment (segment is still
in dirty list)
c) GC migrates '512 - n' blocks to target segment (segment has 'n'
cp_vblocks and '512 - n' vblocks)
d) If GC selects target segment via {AT,}SSR allocator, however there
is no free space in targe segment.

Fixes: 4354994f097d ("f2fs: checkpoint disabling")
Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused FORCE_FG_GC macro

FORCE_FG_GC was introduced by commit 6aefd93b0137 ("f2fs: introduce
background_gc=sync mount option"), but never be used, remove it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

block: rename BIO_MAX_PAGES to BIO_MAX_VECS

Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed. Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

f2fs: handle unallocated section and zone on pinned/atgc

If we have large section/zone, unallocated segment makes them corrupted.

E.g.,

- Pinned file: -1 119304647 119304647
- ATGC data: -1 119304647 119304647

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix wrong total_sections check and fsmeta check

Meta area is not included in section_count computation.
So the minimum number of total_sections is 1 meanwhile it cannot be
greater than segment_count_main.

The minimum number of meta segments is 8 (SB + 2 (CP + SIT + NAT) + SSA).

Signed-off-by: Wang Xiaojun <wangxiaojun11@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change return value of reserved_segments to unsigned int

The type of SM_I(sbi)->reserved_segments is unsigned int,
so change the return value to unsigned int.
The type cast can be removed in reserved_sections as a result.

Signed-off-by: Xiaojun Wang <wangxiaojun11@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support age threshold based garbage collection

There are several issues in current background GC algorithm:
- valid blocks is one of key factors during cost overhead calculation,
so if segment has less valid block, however even its age is young or
it locates hot segment, CB algorithm will still choose the segment as
victim, it's not appropriate.
- GCed data/node will go to existing logs, no matter in-there datas'
update frequency is the same or not, it may mix hot and cold data
again.
- GC alloctor mainly use LFS type segment, it will cost free segment
more quickly.

This patch introduces a new algorithm named age threshold based
garbage collection to solve above issues, there are three steps
mainly:

1. select a source victim:
- set an age threshold, and select candidates beased threshold:
e.g.
0 means youngest, 100 means oldest, if we set age threshold to 80
then select dirty segments which has age in range of [80, 100] as
candiddates;
- set candidate_ratio threshold, and select candidates based the
ratio, so that we can shrink candidates to those oldest segments;
- select target segment with fewest valid blocks in order to
migrate blocks with minimum cost;

2. select a target victim:
- select candidates beased age threshold;
- set candidate_radius threshold, search candidates whose age is
around source victims, searching radius should less than the
radius threshold.
- select target segment with most valid blocks in order to avoid
migrating current target segment.

3. merge valid blocks from source victim into target victim with
SSR alloctor.

Test steps:
- create 160 dirty segments:
* half of them have 128 valid blocks per segment
* left of them have 384 valid blocks per segment
- run background GC

Benefit: GC count and block movement count both decrease obviously:

- Before:
- Valid: 86
- Dirty: 1
- Prefree: 11
- Free: 6001 (6001)

GC calls: 162 (BG: 220)
- data segments : 160 (160)
- node segments : 2 (2)
Try to move 41454 blocks (BG: 41454)
- data blocks : 40960 (40960)
- node blocks : 494 (494)

IPU: 0 blocks
SSR: 0 blocks in 0 segments
LFS: 41364 blocks in 81 segments

- After:

- Valid: 87
- Dirty: 0
- Prefree: 4
- Free: 6008 (6008)

GC calls: 75 (BG: 76)
- data segments : 74 (74)
- node segments : 1 (1)
Try to move 12813 blocks (BG: 12813)
- data blocks : 12544 (12544)
- node blocks : 269 (269)

IPU: 0 blocks
SSR: 12032 blocks in 77 segments
LFS: 855 blocks in 2 segments

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix a bug along with pinfile in-mem segment & clean up]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce inmem curseg

Previous implementation of aligned pinfile allocation will:
- allocate new segment on cold data log no matter whether last used
segment is partially used or not, it makes IOs more random;
- force concurrent cold data/GCed IO going into warm data area, it
can make a bad effect on hot/cold data separation;

In this patch, we introduce a new type of log named 'inmem curseg',
the differents from normal curseg is:
- it reuses existed segment type (CURSEG_XXX_NODE/DATA);
- it only exists in memory, its segno, blkofs, summary will not b
persisted into checkpoint area;

With this new feature, we can enhance scalability of log, special
allocators can be created for purposes:
- pure lfs allocator for aligned pinfile allocation or file
defragmentation
- pure ssr allocator for later feature

So that, let's update aligned pinfile allocation to use this new
inmem curseg fwk.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support zone capacity less than zone size

NVMe Zoned Namespace devices can have zone-capacity less than zone-size.
Zone-capacity indicates the maximum number of sectors that are usable in
a zone beginning from the first sector of the zone. This makes the sectors
sectors after the zone-capacity till zone-size to be unusable.
This patch set tracks zone-size and zone-capacity in zoned devices and
calculate the usable blocks per segment and usable segments per section.

If zone-capacity is less than zone-size mark only those segments which
start before zone-capacity as free segments. All segments at and beyond
zone-capacity are treated as permanently used segments. In cases where
zone-capacity does not align with segment size the last segment will start
before zone-capacity and end beyond the zone-capacity of the zone. For
such spanning segments only sectors within the zone-capacity are used.

During writes and GC manage the usable segments in a section and usable
blocks per segment. Segments which are beyond zone-capacity are never
allocated, and do not need to be garbage collected, only the segments
which are before zone-capacity needs to garbage collected.
For spanning segments based on the number of usable blocks in that
segment, write to blocks only up to zone-capacity.

Zone-capacity is device specific and cannot be configured by the user.
Since NVMe ZNS device zones are sequentially write only, a block device
with conventional zones or any normal block device is needed along with
the ZNS device for the metadata operations of F2fs.

A typical nvme-cli output of a zoned device shows zone start and capacity
and write pointer as below:

SLBA: 0x0 WP: 0x0 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x20000 WP: 0x20000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ
SLBA: 0x40000 WP: 0x40000 Cap: 0x18800 State: EMPTY Type: SEQWRITE_REQ

Here zone size is 64MB, capacity is 49MB, WP is at zone start as the zones
are in EMPTY state. For each zone, only zone start + 49MB is usable area,
any lba/sector after 49MB cannot be read or written to, the drive will fail
any attempts to read/write. So, the second zone starts at 64MB and is
usable till 113MB (64 + 49) and the range between 113 and 128MB is
again unusable. The next zone starts at 128MB, and so on.

Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: segment.h: delete a duplicated word

Drop the repeated word "the" in a comment.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: linux-f2fs-devel@lists.sourceforge.net
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: get the right gc victim section when section has several segments

Assume each section has 4 segment:
.___________________________.
|_Segment0_|_..._|_Segment3_|
. .
. .
.__________.
|_section0_|

Segment 0~2 has 0 valid block, segment 3 has 512 valid blocks.
It will fail if we want to gc section0 in this scenes,
because all 4 segments in section0 is not dirty.
So we should use dirty section bitmap instead of dirty segment bitmap
to get right victim section.

Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to F2FS File System support.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: show mounted time

Let's show mounted time.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: update f2fs document regarding to fsync_mode

This patch adds missing fsync_mode entry in f2fs document.

Fixes: 04485987f053 ("f2fs: introduce async IPU policy")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add a way to turn off ipu bio cache

Setting 0x40 in /sys/fs/f2fs/dev/ipu_policy gives a way to turn off
bio cache, which is useufl to check whether block layer using hardware
encryption engine merges IOs correctly.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support data compression

This patch tries to support compression in f2fs.

- New term named cluster is defined as basic unit of compression, file can
be divided into multiple clusters logically. One cluster includes 4 << n
(n >= 0) logical pages, compression size is also cluster size, each of
cluster can be compressed or not.

- In cluster metadata layout, one special flag is used to indicate cluster
is compressed one or normal one, for compressed cluster, following metadata
maps cluster to [1, 4 << n - 1] physical blocks, in where f2fs stores
data including compress header and compressed data.

- In order to eliminate write amplification during overwrite, F2FS only
support compression on write-once file, data can be compressed only when
all logical blocks in file are valid and cluster compress ratio is lower
than specified threshold.

- To enable compression on regular inode, there are three ways:
* chattr +c file
* chattr +c dir; touch dir/file
* mount w/ -o compress_extension=ext; touch file.ext

Compress metadata layout:
[Dnode Structure]
+-----------------------------------------------+
| cluster 1 | cluster 2 | ......... | cluster N |
+-----------------------------------------------+
. . . .
. . . .
. Compressed Cluster . . Normal Cluster .
+----------+---------+---------+---------+ +---------+---------+---------+---------+
|compr flag| block 1 | block 2 | block 3 | | block 1 | block 2 | block 3 | block 4 |
+----------+---------+---------+---------+ +---------+---------+---------+---------+
. .
. .
. .
+-------------+-------------+----------+----------------------------+
| data length | data chksum | reserved | compressed data |
+-------------+-------------+----------+----------------------------+

Changelog:

20190326:
- fix error handling of read_end_io().
- remove unneeded comments in f2fs_encrypt_one_page().

20190327:
- fix wrong use of f2fs_cluster_is_full() in f2fs_mpage_readpages().
- don't jump into loop directly to avoid uninitialized variables.
- add TODO tag in error path of f2fs_write_cache_pages().

20190328:
- fix wrong merge condition in f2fs_read_multi_pages().
- check compressed file in f2fs_post_read_required().

20190401
- allow overwrite on non-compressed cluster.
- check cluster meta before writing compressed data.

20190402
- don't preallocate blocks for compressed file.

- add lz4 compress algorithm
- process multiple post read works in one workqueue
Now f2fs supports processing post read work in multiple workqueue,
it shows low performance due to schedule overhead of multiple
workqueue executing orderly.

20190921
- compress: support buffered overwrite
C: compress cluster flag
V: valid block address
N: NEW_ADDR

One cluster contain 4 blocks

before overwrite after overwrite

- VVVV -> CVNN
- CVNN -> VVVV

- CVNN -> CVNN
- CVNN -> CVVV

- CVVV -> CVNN
- CVVV -> CVVV

20191029
- add kconfig F2FS_FS_COMPRESSION to isolate compression related
codes, add kconfig F2FS_FS_{LZO,LZ4} to cover backend algorithm.
note that: will remove lzo backend if Jaegeuk agreed that too.
- update codes according to Eric's comments.

20191101
- apply fixes from Jaegeuk

20191113
- apply fixes from Jaegeuk
- split workqueue for fsverity

20191216
- apply fixes from Jaegeuk

20200117
- fix to avoid NULL pointer dereference

[Jaegeuk Kim]
- add tracepoint for f2fs_{,de}compress_pages()
- fix many bugs and add some compression stats
- fix overwrite/mmap bugs
- address 32bit build error, reported by Geert.
- bug fixes when handling errors and i_compressed_blocks

Reported-by: <noreply@ellerman.id.au>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support aligned pinned file

This patch supports 2MB-aligned pinned file, which can guarantee no GC at all
by allocating fully valid 2MB segment.

Check free segments by has_not_enough_free_secs() with large budget.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enhance f2fs_is_checkpoint_ready()'s readability

This patch changes sematics of f2fs_is_checkpoint_ready()'s return
value as: return true when checkpoint is ready, other return false,
it can improve readability of below conditions.

f2fs_submit_page_write()
...
if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
!f2fs_is_checkpoint_ready(sbi))
__submit_merged_bio(io);

f2fs_balance_fs()
...
if (!f2fs_is_checkpoint_ready(sbi))
return;

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Fix indefinite loop in f2fs_gc()

Policy - Foreground GC, LFS and greedy GC mode.

Under this policy, f2fs_gc() loops forever to GC as it doesn't have
enough free segements to proceed and thus it keeps calling gc_more
for the same victim segment. This can happen if the selected victim
segment could not be GC'd due to failed blkaddr validity check i.e.
is_alive() returns false for the blocks set in current validity map.

Fix this by keeping track of such invalid segments and skip those
segments for selection in get_victim_by_default() to avoid endless
GC loop under such error scenarios. Currently, add this logic under
CONFIG_F2FS_CHECK_FS to be able to root cause the issue in debug
version.

Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong bitmap size]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: allocate memory in batch in build_sit_info()

build_sit_info() allocate all bitmaps for each segment one by one,
it's quite low efficiency, this pach changes to allocate large
continuous memory at a time, and divide it and assign for each bitmaps
of segment. For large size image, it can expect improving its mount
speed.

Signed-off-by: Chen Gong <gongchen4@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use generic EFSBADCRC/EFSCORRUPTED

f2fs uses EFAULT as error number to indicate filesystem is corrupted
all the time, but generic filesystems use EUCLEAN for such condition,
we need to change to follow others.

This patch adds two new macros as below to wrap more generic error
code macros, and spread them in code.

EFSBADCRC EBADMSG /* Bad CRC detected */
EFSCORRUPTED EUCLEAN /* Filesystem is corrupted */

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Use DIV_ROUND_UP() instead of open-coding

Replace the open-coded divisions with round-up by calls to the
DIV_ROUND_UP() helper macro.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_<level> macros to wrap f2fs_printk()

- Add and use f2fs_<level> macros
- Convert f2fs_msg to f2fs_printk
- Remove level from f2fs_printk and embed the level in the format
- Coalesce formats and align multi-line arguments
- Remove unnecessary duplicate extern f2fs_msg f2fs.h

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce DATA_GENERIC_ENHANCE

Previously, f2fs_is_valid_blkaddr(, blkaddr, DATA_GENERIC) will check
whether @blkaddr locates in main area or not.

That check is weak, since the block address in range of main area can
point to the address which is not valid in segment info table, and we
can not detect such condition, we may suffer worse corruption as system
continues running.

So this patch introduce DATA_GENERIC_ENHANCE to enhance the sanity check
which trigger SIT bitmap check rather than only range check.

This patch did below changes as wel:
- set SBI_NEED_FSCK in f2fs_is_valid_blkaddr().
- get rid of is_valid_data_blkaddr() to avoid panic if blkaddr is invalid.
- introduce verify_fio_blkaddr() to wrap fio {new,old}_blkaddr validation check.
- spread blkaddr check in:
* f2fs_get_node_info()
* __read_out_blkaddrs()
* f2fs_submit_page_read()
* ra_data_block()
* do_recover_data()

This patch can fix bug reported from bugzilla below:

https://bugzilla.kernel.org/show_bug.cgi?id=203215
https://bugzilla.kernel.org/show_bug.cgi?id=203223
https://bugzilla.kernel.org/show_bug.cgi?id=203231
https://bugzilla.kernel.org/show_bug.cgi?id=203235
https://bugzilla.kernel.org/show_bug.cgi?id=203241

= Update by Jaegeuk Kim =

DATA_GENERIC_ENHANCE enhanced to validate block addresses on read/write paths.
But, xfstest/generic/446 compalins some generated kernel messages saying invalid
bitmap was detected when reading a block. The reaons is, when we get the
block addresses from extent_cache, there is no lock to synchronize it from
truncating the blocks in parallel.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check on valid block count of segment

As Jungyeon reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=203233

- Overview
When mounting the attached crafted image and running program, following errors are reported.
Additionally, it hangs on sync after running program.

The image is intentionally fuzzed from a normal f2fs image for testing.
Compile options for F2FS are as follows.
CONFIG_F2FS_FS=y
CONFIG_F2FS_STAT_FS=y
CONFIG_F2FS_FS_XATTR=y
CONFIG_F2FS_FS_POSIX_ACL=y
CONFIG_F2FS_CHECK_FS=y

- Reproduces
cc poc_13.c
mkdir test
mount -t f2fs tmp.img test
cp a.out test
cd test
sudo ./a.out
sync

- Kernel messages
F2FS-fs (sdb): Bitmap was wrongly set, blk:4608
kernel BUG at fs/f2fs/segment.c:2102!
RIP: 0010:update_sit_entry+0x394/0x410
Call Trace:
f2fs_allocate_data_block+0x16f/0x660
do_write_page+0x62/0x170
f2fs_do_write_node_page+0x33/0xa0
__write_node_page+0x270/0x4e0
f2fs_sync_node_pages+0x5df/0x670
f2fs_write_checkpoint+0x372/0x1400
f2fs_sync_fs+0xa3/0x130
f2fs_do_sync_file+0x1a6/0x810
do_fsync+0x33/0x60
__x64_sys_fsync+0xb/0x10
do_syscall_64+0x43/0xf0
entry_SYSCALL_64_after_hwframe+0x44/0xa9

sit.vblocks and sum valid block count in sit.valid_map may be
inconsistent, segment w/ zero vblocks will be treated as free
segment, while allocating in free segment, we may allocate a
free block, if its bitmap is valid previously, it can cause
kernel crash due to bitmap verification failure.

Anyway, to avoid further serious metadata inconsistence and
corruption, it is necessary and worth to detect SIT
inconsistence. So let's enable check_block_count() to verify
vblocks and valid_map all the time rather than do it only
CONFIG_F2FS_CHECK_FS is enabled.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't wake up too frequently, if there is lots of IOs

Otherwise, it wakes up discard thread which will sleep again by busy IOs
in a loop.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce __is_large_section() for cleanup

Introduce a wrapper __is_large_section() to clean up codes.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: checkpoint disabling

Note that, it requires "f2fs: return correct errno in f2fs_gc".

This adds a lightweight non-persistent snapshotting scheme to f2fs.

To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add SPDX license identifiers

Remove the verbose license text from f2fs files and replace them with
SPDX tags. This does not change the license of any of the code.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc

The f2fs_gc() called by f2fs_balance_fs() requires to be called outside of
fi->i_gc_rwsem[WRITE], since f2fs_gc() can try to grab it in a loop.

If it hits the miximum retrials in GC, let's give a chance to release
gc_mutex for a short time in order not to go into live lock in the worst
case.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not set free of current section

For the case when sbi->segs_per_sec > 1, take section:segment = 5 for
example, if segment 1 is just used and allocate new segment 2, and the
blocks of segment 1 is invalidated, at this time, the previous code will
use __set_test_and_free to free the free_secmap and free_sections++,
this is not correct since it is still a current section, so fix it.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to do sanity check with block address in main area

This patch add to do sanity check with below field:
- cp_pack_total_block_count
- blkaddr of data/node
- extent info

- Overview
BUG() in verify_block_addr() when writing to a corrupted f2fs image

- Reproduce (4.18 upstream kernel)

- POC (poc.c)

static void activity(char *mpoint) {

char *foo_bar_baz;
int err;

static int buf[8192];
memset(buf, 0, sizeof(buf));

err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint);

int fd = open(foo_bar_baz, O_RDWR | O_TRUNC, 0777);
if (fd >= 0) {
write(fd, (char *)buf, sizeof(buf));
fdatasync(fd);
close(fd);
}
}

int main(int argc, char *argv[]) {
activity(argv[1]);
return 0;
}

- Kernel message
[ 689.349473] F2FS-fs (loop0): Mounted with checkpoint version = 3
[ 699.728662] WARNING: CPU: 0 PID: 1309 at fs/f2fs/segment.c:2860 f2fs_inplace_write_data+0x232/0x240
[ 699.728670] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy
[ 699.729056] CPU: 0 PID: 1309 Comm: a.out Not tainted 4.18.0-rc1+ #4
[ 699.729064] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 699.729074] RIP: 0010:f2fs_inplace_write_data+0x232/0x240
[ 699.729076] Code: ff e9 cf fe ff ff 49 8d 7d 10 e8 39 45 ad ff 4d 8b 7d 10 be 04 00 00 00 49 8d 7f 48 e8 07 49 ad ff 45 8b 7f 48 e9 fb fe ff ff <0f> 0b f0 41 80 4d 48 04 e9 65 fe ff ff 90 66 66 66 66 90 55 48 8d
[ 699.729130] RSP: 0018:ffff8801f43af568 EFLAGS: 00010202
[ 699.729139] RAX: 000000000000003f RBX: ffff8801f43af7b8 RCX: ffffffffb88c9113
[ 699.729142] RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffff8802024e5540
[ 699.729144] RBP: ffff8801f43af590 R08: 0000000000000009 R09: ffffffffffffffe8
[ 699.729147] R10: 0000000000000001 R11: ffffed0039b0596a R12: ffff8802024e5540
[ 699.729149] R13: ffff8801f0335500 R14: ffff8801e3e7a700 R15: ffff8801e1ee4450
[ 699.729154] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[ 699.729156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 699.729159] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[ 699.729171] Call Trace:
[ 699.729192] f2fs_do_write_data_page+0x2e2/0xe00
[ 699.729203] ? f2fs_should_update_outplace+0xd0/0xd0
[ 699.729238] ? memcg_drain_all_list_lrus+0x280/0x280
[ 699.729269] ? __radix_tree_replace+0xa3/0x120
[ 699.729276] __write_data_page+0x5c7/0xe30
[ 699.729291] ? kasan_check_read+0x11/0x20
[ 699.729310] ? page_mapped+0x8a/0x110
[ 699.729321] ? page_mkclean+0xe9/0x160
[ 699.729327] ? f2fs_do_write_data_page+0xe00/0xe00
[ 699.729331] ? invalid_page_referenced_vma+0x130/0x130
[ 699.729345] ? clear_page_dirty_for_io+0x332/0x450
[ 699.729351] f2fs_write_cache_pages+0x4ca/0x860
[ 699.729358] ? __write_data_page+0xe30/0xe30
[ 699.729374] ? percpu_counter_add_batch+0x22/0xa0
[ 699.729380] ? kasan_check_write+0x14/0x20
[ 699.729391] ? _raw_spin_lock+0x17/0x40
[ 699.729403] ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30
[ 699.729413] ? iov_iter_advance+0x113/0x640
[ 699.729418] ? f2fs_write_end+0x133/0x2e0
[ 699.729423] ? balance_dirty_pages_ratelimited+0x239/0x640
[ 699.729428] f2fs_write_data_pages+0x329/0x520
[ 699.729433] ? generic_perform_write+0x250/0x320
[ 699.729438] ? f2fs_write_cache_pages+0x860/0x860
[ 699.729454] ? current_time+0x110/0x110
[ 699.729459] ? f2fs_preallocate_blocks+0x1ef/0x370
[ 699.729464] do_writepages+0x37/0xb0
[ 699.729468] ? f2fs_write_cache_pages+0x860/0x860
[ 699.729472] ? do_writepages+0x37/0xb0
[ 699.729478] __filemap_fdatawrite_range+0x19a/0x1f0
[ 699.729483] ? delete_from_page_cache_batch+0x4e0/0x4e0
[ 699.729496] ? __vfs_write+0x2b2/0x410
[ 699.729501] file_write_and_wait_range+0x66/0xb0
[ 699.729506] f2fs_do_sync_file+0x1f9/0xd90
[ 699.729511] ? truncate_partial_data_page+0x290/0x290
[ 699.729521] ? __sb_end_write+0x30/0x50
[ 699.729526] ? vfs_write+0x20f/0x260
[ 699.729530] f2fs_sync_file+0x9a/0xb0
[ 699.729534] ? f2fs_do_sync_file+0xd90/0xd90
[ 699.729548] vfs_fsync_range+0x68/0x100
[ 699.729554] ? __fget_light+0xc9/0xe0
[ 699.729558] do_fsync+0x3d/0x70
[ 699.729562] __x64_sys_fdatasync+0x24/0x30
[ 699.729585] do_syscall_64+0x78/0x170
[ 699.729595] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 699.729613] RIP: 0033:0x7f9bf930d800
[ 699.729615] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24
[ 699.729668] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[ 699.729673] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[ 699.729675] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[ 699.729678] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[ 699.729680] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[ 699.729683] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000
[ 699.729687] ---[ end trace 4ce02f25ff7d3df5 ]---
[ 699.729782] ------------[ cut here ]------------
[ 699.729785] kernel BUG at fs/f2fs/segment.h:654!
[ 699.731055] invalid opcode: 0000 [#1] SMP KASAN PTI
[ 699.732104] CPU: 0 PID: 1309 Comm: a.out Tainted: G W 4.18.0-rc1+ #4
[ 699.733684] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 699.735611] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730
[ 699.736649] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0
[ 699.740524] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283
[ 699.741573] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef
[ 699.743006] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c
[ 699.744426] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55
[ 699.745833] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940
[ 699.747256] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001
[ 699.748683] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[ 699.750293] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 699.751462] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[ 699.752874] Call Trace:
[ 699.753386] ? f2fs_inplace_write_data+0x93/0x240
[ 699.754341] f2fs_inplace_write_data+0xd2/0x240
[ 699.755271] f2fs_do_write_data_page+0x2e2/0xe00
[ 699.756214] ? f2fs_should_update_outplace+0xd0/0xd0
[ 699.757215] ? memcg_drain_all_list_lrus+0x280/0x280
[ 699.758209] ? __radix_tree_replace+0xa3/0x120
[ 699.759164] __write_data_page+0x5c7/0xe30
[ 699.760002] ? kasan_check_read+0x11/0x20
[ 699.760823] ? page_mapped+0x8a/0x110
[ 699.761573] ? page_mkclean+0xe9/0x160
[ 699.762345] ? f2fs_do_write_data_page+0xe00/0xe00
[ 699.763332] ? invalid_page_referenced_vma+0x130/0x130
[ 699.764374] ? clear_page_dirty_for_io+0x332/0x450
[ 699.765347] f2fs_write_cache_pages+0x4ca/0x860
[ 699.766276] ? __write_data_page+0xe30/0xe30
[ 699.767161] ? percpu_counter_add_batch+0x22/0xa0
[ 699.768112] ? kasan_check_write+0x14/0x20
[ 699.768951] ? _raw_spin_lock+0x17/0x40
[ 699.769739] ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30
[ 699.770885] ? iov_iter_advance+0x113/0x640
[ 699.771743] ? f2fs_write_end+0x133/0x2e0
[ 699.772569] ? balance_dirty_pages_ratelimited+0x239/0x640
[ 699.773680] f2fs_write_data_pages+0x329/0x520
[ 699.774603] ? generic_perform_write+0x250/0x320
[ 699.775544] ? f2fs_write_cache_pages+0x860/0x860
[ 699.776510] ? current_time+0x110/0x110
[ 699.777299] ? f2fs_preallocate_blocks+0x1ef/0x370
[ 699.778279] do_writepages+0x37/0xb0
[ 699.779026] ? f2fs_write_cache_pages+0x860/0x860
[ 699.779978] ? do_writepages+0x37/0xb0
[ 699.780755] __filemap_fdatawrite_range+0x19a/0x1f0
[ 699.781746] ? delete_from_page_cache_batch+0x4e0/0x4e0
[ 699.782820] ? __vfs_write+0x2b2/0x410
[ 699.783597] file_write_and_wait_range+0x66/0xb0
[ 699.784540] f2fs_do_sync_file+0x1f9/0xd90
[ 699.785381] ? truncate_partial_data_page+0x290/0x290
[ 699.786415] ? __sb_end_write+0x30/0x50
[ 699.787204] ? vfs_write+0x20f/0x260
[ 699.787941] f2fs_sync_file+0x9a/0xb0
[ 699.788694] ? f2fs_do_sync_file+0xd90/0xd90
[ 699.789572] vfs_fsync_range+0x68/0x100
[ 699.790360] ? __fget_light+0xc9/0xe0
[ 699.791128] do_fsync+0x3d/0x70
[ 699.791779] __x64_sys_fdatasync+0x24/0x30
[ 699.792614] do_syscall_64+0x78/0x170
[ 699.793371] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 699.794406] RIP: 0033:0x7f9bf930d800
[ 699.795134] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24
[ 699.798960] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[ 699.800483] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[ 699.801923] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[ 699.803373] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[ 699.804798] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[ 699.806233] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000
[ 699.807667] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy
[ 699.817079] ---[ end trace 4ce02f25ff7d3df6 ]---
[ 699.818068] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730
[ 699.819114] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0
[ 699.822919] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283
[ 699.823977] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef
[ 699.825436] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c
[ 699.826881] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55
[ 699.828292] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940
[ 699.829750] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001
[ 699.831192] FS: 00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[ 699.832793] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 699.833981] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[ 699.835556] ==================================================================
[ 699.837029] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x38c/0x3e0
[ 699.838462] Read of size 8 at addr ffff8801f43af970 by task a.out/1309

[ 699.840086] CPU: 0 PID: 1309 Comm: a.out Tainted: G D W 4.18.0-rc1+ #4
[ 699.841603] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 699.843475] Call Trace:
[ 699.843982] dump_stack+0x7b/0xb5
[ 699.844661] print_address_description+0x70/0x290
[ 699.845607] kasan_report+0x291/0x390
[ 699.846351] ? update_stack_state+0x38c/0x3e0
[ 699.853831] __asan_load8+0x54/0x90
[ 699.854569] update_stack_state+0x38c/0x3e0
[ 699.855428] ? __read_once_size_nocheck.constprop.7+0x20/0x20
[ 699.856601] ? __save_stack_trace+0x5e/0x100
[ 699.857476] unwind_next_frame.part.5+0x18e/0x490
[ 699.858448] ? unwind_dump+0x290/0x290
[ 699.859217] ? clear_page_dirty_for_io+0x332/0x450
[ 699.860185] __unwind_start+0x106/0x190
[ 699.860974] __save_stack_trace+0x5e/0x100
[ 699.861808] ? __save_stack_trace+0x5e/0x100
[ 699.862691] ? unlink_anon_vmas+0xba/0x2c0
[ 699.863525] save_stack_trace+0x1f/0x30
[ 699.864312] save_stack+0x46/0xd0
[ 699.864993] ? __alloc_pages_slowpath+0x1420/0x1420
[ 699.865990] ? flush_tlb_mm_range+0x15e/0x220
[ 699.866889] ? kasan_check_write+0x14/0x20
[ 699.867724] ? __dec_node_state+0x92/0xb0
[ 699.868543] ? lock_page_memcg+0x85/0xf0
[ 699.869350] ? unlock_page_memcg+0x16/0x80
[ 699.870185] ? page_remove_rmap+0x198/0x520
[ 699.871048] ? mark_page_accessed+0x133/0x200
[ 699.871930] ? _cond_resched+0x1a/0x50
[ 699.872700] ? unmap_page_range+0xcd4/0xe50
[ 699.873551] ? rb_next+0x58/0x80
[ 699.874217] ? rb_next+0x58/0x80
[ 699.874895] __kasan_slab_free+0x13c/0x1a0
[ 699.875734] ? unlink_anon_vmas+0xba/0x2c0
[ 699.876563] kasan_slab_free+0xe/0x10
[ 699.877315] kmem_cache_free+0x89/0x1e0
[ 699.878095] unlink_anon_vmas+0xba/0x2c0
[ 699.878913] free_pgtables+0x101/0x1b0
[ 699.879677] exit_mmap+0x146/0x2a0
[ 699.880378] ? __ia32_sys_munmap+0x50/0x50
[ 699.881214] ? kasan_check_read+0x11/0x20
[ 699.882052] ? mm_update_next_owner+0x322/0x380
[ 699.882985] mmput+0x8b/0x1d0
[ 699.883602] do_exit+0x43a/0x1390
[ 699.884288] ? mm_update_next_owner+0x380/0x380
[ 699.885212] ? f2fs_sync_file+0x9a/0xb0
[ 699.885995] ? f2fs_do_sync_file+0xd90/0xd90
[ 699.886877] ? vfs_fsync_range+0x68/0x100
[ 699.887694] ? __fget_light+0xc9/0xe0
[ 699.888442] ? do_fsync+0x3d/0x70
[ 699.889118] ? __x64_sys_fdatasync+0x24/0x30
[ 699.889996] rewind_stack_do_exit+0x17/0x20
[ 699.890860] RIP: 0033:0x7f9bf930d800
[ 699.891585] Code: Bad RIP value.
[ 699.892268] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[ 699.893781] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[ 699.895220] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[ 699.896643] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[ 699.898069] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[ 699.899505] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000

[ 699.901241] The buggy address belongs to the page:
[ 699.902215] page:ffffea0007d0ebc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[ 699.903811] flags: 0x2ffff0000000000()
[ 699.904585] raw: 02ffff0000000000 0000000000000000 ffffffff07d00101 0000000000000000
[ 699.906125] raw: 0000000000000000 0000000000240000 00000000ffffffff 0000000000000000
[ 699.907673] page dumped because: kasan: bad access detected

[ 699.909108] Memory state around the buggy address:
[ 699.910077] ffff8801f43af800: 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 00
[ 699.911528] ffff8801f43af880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 699.912953] >ffff8801f43af900: 00 00 00 00 00 00 00 00 f1 01 f4 f4 f4 f2 f2 f2
[ 699.914392] ^
[ 699.915758] ffff8801f43af980: f2 00 f4 f4 00 00 00 00 f2 00 00 00 00 00 00 00
[ 699.917193] ffff8801f43afa00: 00 00 00 00 00 00 00 00 00 f3 f3 f3 00 00 00 00
[ 699.918634] ==================================================================

- Location
https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.h#L644

Reported-by Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce and spread verify_blkaddr

This patch introduces verify_blkaddr to check meta/data block address
with valid range to detect bug earlier.

In addition, once we encounter an invalid blkaddr, notice user to run
fsck to fix, and let the kernel panic.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to update mtime correctly

If we change system time to the past, get_mtime() will return a
overflowed time, and SIT_I(sbi)->max_mtime will be udpated
incorrectly, this patch fixes the two issues.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid stucking GC due to atomic write

f2fs doesn't allow abuse on atomic write class interface, so except
limiting in-mem pages' total memory usage capacity, we need to limit
atomic-write usage as well when filesystem is seriously fragmented,
otherwise we may run into infinite loop during foreground GC because
target blocks in victim segment are belong to atomic opened file for
long time.

Now, we will detect failure due to atomic write in foreground GC, if
the count exceeds threshold, we will drop all atomic written data in
cache, by this, I expect it can keep our system running safely to
prevent Dos attack.

In addition, his patch adds to show GC skip information in debugfs,
now it just shows count of skipped caused by atomic write.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up with is_valid_blkaddr()

- rename is_valid_blkaddr() to is_valid_meta_blkaddr() for readability.
- introduce is_valid_blkaddr() for cleanup.

No logic change in this patch.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Revert "f2fs: add ovp valid_blocks check for bg gc victim to fg_gc"

For extreme case:
10 section, op = 10%, no_fggc_threshold = 90%
All section usage: 85% 85% 85% 85% 90% 90% 95% 95% 95% 95%

During foreground GC, if we skip select dirty section whose usage
is larger than no_fggc_threshold, we can only recycle 80% invalid
space from four 85% usage sections and two 90% usage sections,
result in encountering out-of-space issue.

This reverts commit e93b9865251a0503d83fd570e7d5a7c8bc351715 to
fix this issue, besides, we keep the logic that we scan all dirty
section when searching a victim, so that GC can select victim with
least valid blocks.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't use GFP_ZERO for page caches

Related to https://lkml.org/lkml/2018/4/8/661

Sometimes, we need to write meta data to new allocated block address,
then we will allocate a zeroed page in inner inode's address space, and
fill partial data in it, and leave other place with zero value which means
some fields are initial status.

There are two inner inodes (meta inode and node inode) setting __GFP_ZERO,
I have just checked them, for both of them, we can avoid using __GFP_ZERO,
and do initialization by ourselves to avoid unneeded/redundant zeroing
from mm.

Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check blkaddr more accuratly before issue a bio

This patch check blkaddr more accuratly before issue a
write or read bio.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add auto tuning for small devices

If f2fs is running on top of very small devices, it's worth to avoid abusing
free LBAs. In order to achieve that, this patch introduces some parameter
tuning.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: rebuild sit page from sit info in mem

This patch rebuild sit page from sit info in mem instead
of issue a read io.

I test this method and the result is as below:

Pre:
mmc_perf_test-12061 [001] ...1 976.819992: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [001] ...1 976.856446: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 998.976946: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 999.023269: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1022.060772: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1022.111034: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [002] ...1 1070.127643: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1070.187352: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1095.942124: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1095.995975: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1122.535091: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [003] ...1 1122.586521: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [001] ...1 1147.897487: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [001] ...1 1147.959438: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [003] ...1 1177.926951: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [002] ...1 1177.976823: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-12061 [002] ...1 1204.176087: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-12061 [002] ...1 1204.239046: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit

Some sit flush consume more than 50ms.

Now:
mmc_perf_test-2187 [007] ...1 196.840684: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [007] ...1 196.841258: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [007] ...1 219.430582: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [007] ...1 219.431144: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [002] ...1 243.638678: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 243.638980: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [002] ...1 265.392180: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [002] ...1 265.392245: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [000] ...1 290.309051: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 290.309116: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [003] ...1 317.144209: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [003] ...1 317.145913: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [005] ...1 343.224954: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [005] ...1 343.225574: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [000] ...1 370.239846: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [000] ...1 370.241138: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [001] ...1 397.029043: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [001] ...1 397.030750: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit
mmc_perf_test-2187 [003] ...1 425.386377: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = start flush sit
mmc_perf_test-2187 [003] ...1 425.387735: f2fs_write_checkpoint: dev = (259,44), checkpoint for Sync, state = end flush sit

Most sit flush consume no more than 1ms.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split need_inplace_update

This patch splits need_inplace_update to two functions:
a. should_update_inplace() includes all conditions that we must use IPU.
b. should_update_outplace() includes all conditions that we must use OPU.

So that, in f2fs_ioc_set_pin_file() and f2fs_defragment_range(), we can
use corresponding function to check whether we can trigger OPU/IPU or not.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: return error during fill_super

Let's avoid BUG_ON during fill_super, when on-disk was totall corrupted.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check curseg space before foreground GC

When we are closing to trigger foreground GC, if there are only a few
of dirty metas, we can log these dirty metas in left space of opened
segments instead of triggering foreground GC.

With this patch, total count of foreground GC triggered by
test/generic/* of fstest suit reduce from 254 to 184.

So let's do the check before foreground GC anyway.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use rw_semaphore to protect SIT cache

There are some cases user didn't update SIT cache under this lock,
so let's use rw_semaphore instead of mutex to enhance concurrently
accessing.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to correct no_fggc_candidate

There may be extreme case as below:

For one section contains one segment, and there are total 100 segments
with 10% over-privision ratio in f2fs partition, fggc_threshold will
be rounded down to 460 instead of 460.8 as below caclulation:

sbi->fggc_threshold = div_u64((u64)(main_count - ovp_count) *
BLKS_PER_SEC(sbi), (main_count - resv_count));

If section usage is as:
60 segments which contain 460 valid blocks
40 segments which contain 462 valid blocks

As valid block number in all sections is large than fggc_threshold, so
none of them will be chosen as candidate due to incorrect fggc_threshold.

Let's just soften the term of choosing foreground GC candidates.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split discard policy

There are many different scenarios such as fstrim, umount, urgent or
background where we will issue discards, actually, they need use
different policy in aspect of io aware, discard granularity, delay
interval and so on. But now they just share one common discard policy,
so there will be race when changing policy in between these scenarios,
the interference of changing discard policy will be very serious.

This patch changes to split discard policy for different scenarios.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: speed up gc_urgent mode with SSR

This patch activates SSR in gc_urgent mode.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: wake up discard_thread iff there is a candidate

This patch fixes to avoid needless wake ups.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused function overprovision_sections

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use IPU for cold files

We expect cold files write data sequentially, but sometimes some of small data
can be updated, which incurs fragmentation.
Let's avoid that.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split bio cache

Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs: f2fs: use ktime_get_real_seconds for sit_info times

CURRENT_TIME_SEC is not y2038 safe.

Replace use of CURRENT_TIME_SEC with ktime_get_real_seconds in segment
timestamps used by GC algorithm including the segment mtime timestamps.

Link: http://lkml.kernel.org/r/1491613030-11599-2-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

f2fs: reconstruct code to write a data page

This patch introduces encrypt_one_page which encrypts one data page before
submit_bio, and change the use of need_inplace_update.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: skip encrypted inode in ASYNC IPU policy

Async request may be throttled in block layer, so page for async may keep WRITE_BACK
for a long time.

For encrytped inode, we need wait on page writeback no matter if the device supports
BDI_CAP_STABLE_WRITES. This may result in a higher waiting page writeback time for
async encrypted inode page.

This patch skips IPU for encrypted inode's updating write.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add ioctl to flush data from faster device to cold area

This patch adds an ioctl to flush data in faster device to cold area. User can
give device number and number of segments to move. It doesn't move it if there
is only one device.

The parameter looks like:

struct f2fs_flush_device {
u32 dev_num; /* device number to flush */
u32 segments; /* # of segments to flush */
};

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce async IPU policy

This patch introduces an ASYNC IPU policy.

Under senario of large # of async updating(e.g. log writing in Android),
disk would be seriously fragmented, and higher frequent gc would be triggered.

This patch uses IPU to rewrite the async update writting, since async is
NOT sensitive to io latency.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>

f2fs: clean up some macros in terms of GET_SEGNO

This patch cleans several macros by introducing:
- BLKS_PER_SEC
- GET_SEC_FROM_SEG
- GET_SEG_FROM_SEC
- GET_ZONE_FROM_SEC
- GET_ZONE_FROM_SEG

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up get_valid_blocks with consistent parameter

This patch cleans up get_valid_blocks, which has no functional change.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use segment number for get_valid_blocks

This patch fixes to submit a segment number for get_valid_blocks.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: guard macro variables with braces

Add braces around variables used within macros for those make sense
to do it. Many of the macros in f2fs already do this. What this commit
doesn't do is anything that changes line# as a result of adding braces,
which usually affects the binary via __LINE__.

Confirmed no diff in fs/f2fs/f2fs.ko before/after this commit on x86_64,
to make sure this has no functional change as well as there's been no
unexpected side effect due to callers' arithmetics within the existing
code.

Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: write small sized IO to hot log

It would better split small and large IOs separately in order to get more
consecutive big writes.

The default threshold is set to 64KB, but configurable by sysfs/min_hot_blocks.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: start SSR much eariler to avoid FG_GC

This patch initiates SSR much eariler, resulting in less FG_GC.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: update the comment of default nr_pages to skipping

Fixes: 2c237ebaa4 ("f2fs: avoid writing node/metapages during writes")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add ovp valid_blocks check for bg gc victim to fg_gc

For foreground gc, greedy algorithm should be adapted, which makes
this formula work well:

(2 * (100 / config.overprovision + 1) + 6)

But currently, we fg_gc have a prior to select bg_gc victim segments to gc
first, these victims are selected by cost-benefit algorithm, we can't guarantee
such segments have the small valid blocks, which may destroy the f2fs rule, on
the worstest case, would consume all the free segments.

This patch fix this by add a filter in check_bg_victims, if segment's has # of
valid blocks over overprovision ratio, skip such segments.

Cc: <stable@vger.kernel.org>
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check in-memory sit version bitmap

This patch adds a mirror for sit version bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check in-memory block bitmap

This patch adds a mirror for valid block bitmap, and use it to detect
in-memory bitmap corruption which may be caused by bit-transition of
cache or memory overflow.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support IO alignment for DATA and NODE writes

This patch implements IO alignment by filling dummy blocks in DATA and NODE
write bios. If we can guarantee, for example, 32KB or 64KB for such the IOs,
we can eliminate underlying dummy page problem which FTL conducts in order to
close MLC or TLC partial written pages.

Note that,
- it requires "-o mode=lfs".
- IO size should be power of 2, not exceed BIO_MAX_PAGES, 256.
- read IO is still 4KB.
- do checkpoint at fsync, if dummy NODE page was written.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: detect wrong layout

Previous mkfs.f2fs allows small partition inappropriately, so f2fs should detect
that as well.

Refer this in f2fs-tools.

mkfs.f2fs: detect small partition by overprovision ratio and # of segments

Reported-and-Tested-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use BIO_MAX_PAGES for bio allocation

We don't need to allocate bio partially in order to maximize sequential writes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: count dirty inodes to flush node pages during checkpoint

If there are a lot of dirty inodes, we need to flush all of them when doing
checkpoint. So, we need to count this for enough free space.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check free_sections for defragmentation

Fix wrong condition check for defragmentation of a file.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: not allow to write illegal blkaddr

we came across an error as below:

[build_nat_area_bitmap:1710] nid[0x 1718] addr[0x 1c18ddc] ino[0x 1718]
[build_nat_area_bitmap:1710] nid[0x 1719] addr[0x 1c193d5] ino[0x 1719]
[build_nat_area_bitmap:1710] nid[0x 171a] addr[0x 1c1736e] ino[0x 171a]
[build_nat_area_bitmap:1710] nid[0x 171b] addr[0x 58b3ee8f] ino[0x815f92ed]
[build_nat_area_bitmap:1710] nid[0x 171c] addr[0x fcdc94b] ino[0x49366377]
[build_nat_area_bitmap:1710] nid[0x 171d] addr[0x 7cd2facf] ino[0xb3c55300]
[build_nat_area_bitmap:1710] nid[0x 171e] addr[0x bd4e25d0] ino[0x77c34c09]

... ...

[build_nat_area_bitmap:1710] nid[0x 1718] addr[0x 1c18ddc] ino[0x 1718]
[build_nat_area_bitmap:1710] nid[0x 1719] addr[0x 1c193d5] ino[0x 1719]
[build_nat_area_bitmap:1710] nid[0x 171a] addr[0x 1c1736e] ino[0x 171a]
[build_nat_area_bitmap:1710] nid[0x 171b] addr[0x 58b3ee8f] ino[0x815f92ed]
[build_nat_area_bitmap:1710] nid[0x 171c] addr[0x fcdc94b] ino[0x49366377]
[build_nat_area_bitmap:1710] nid[0x 171d] addr[0x 7cd2facf] ino[0xb3c55300]
[build_nat_area_bitmap:1710] nid[0x 171e] addr[0x bd4e25d0] ino[0x77c34c09]

One nat block may be stepped by a data block, so this patch forbid to
write if the blkaddr is illegal

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add maximum prefree segments

In 1TB storage, we need to admit 22841 prefree segments, which can consume
too much segments.
This patch sets 8GB in max. prefree segments in that case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid writing node/metapages during writes

Let's keep more node/meta pages in run time.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce mode=lfs mount option

This mount option is to enable original log-structured filesystem forcefully.
So, there should be no random writes for main area.

Especially, this supports host-managed SMR device.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not skip writing data pages

For data pages, let's try to flush as much as possible in background.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
Before : 800 MB/s
After : 1.1 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
Before : 1.3 GB/s
After : 2.2 GB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: flush inode metadata when checkpoint is doing

This patch registers all the inodes which have dirty metadata to sync when
checkpoint is doing.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use inode pointer for {set, clear}_inode_flag

This patch refactors to use inode pointer for set_inode_flag and
clear_inode_flag.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: shrink size of struct seg_entry

Restructure struct seg_entry to eliminate holes in it, after that,
in 32-bits machine, it reduces size from 32 bytes to 24 bytes; in
64-bits machine, it reduces size from 56 bytes to 40 bytes.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split journal cache from curseg cache

In curseg cache, f2fs caches two different parts:
- datas of current summay block, i.e. summary entries, footer info.
- journal info, i.e. sparse nat/sit entries or io stat info.

With this approach, 1) it may cause higher lock contention when we access
or update both of the parts of cache since we use the same mutex lock
curseg_mutex to protect the cache. 2) current summary block with last
journal info will be writebacked into device as a normal summary block
when flushing, however, we treat journal info as valid one only in current
summary, so most normal summary blocks contain junk journal data, it wastes
remaining space of summary block.

So, in order to fix above issues, we split curseg cache into two parts:
a) current summary block, protected by original mutex lock curseg_mutex
b) journal cache, protected by newly introduced r/w semaphore journal_rwsem

When loading curseg cache during ->mount, we store summary info and
journal info into different caches; When doing checkpoint, we combine
datas of two cache into current summary block for persisting.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support revoking atomic written pages

f2fs support atomic write with following semantics:
1. open db file
2. ioctl start atomic write
3. (write db file) * n
4. ioctl commit atomic write
5. close db file

With this flow we can avoid file becoming corrupted when abnormal power
cut, because we hold data of transaction in referenced pages linked in
inmem_pages list of inode, but without setting them dirty, so these data
won't be persisted unless we commit them in step 4.

But we should still hold journal db file in memory by using volatile
write, because our semantics of 'atomic write support' is incomplete, in
step 4, we could fail to submit all dirty data of transaction, once
partial dirty data was committed in storage, then after a checkpoint &
abnormal power-cut, db file will be corrupted forever.

So this patch tries to improve atomic write flow by adding a revoking flow,
once inner error occurs in committing, this gives another chance to try to
revoke these partial submitted data of current transaction, it makes
committing operation more like aotmical one.

If we're not lucky, once revoking operation was failed, EAGAIN will be
reported to user for suggesting doing the recovery with held journal file,
or retrying current transaction again.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix conflict on page->private usage

This patch fixes confilct on page->private value between f2fs_trace_pid and
atomic page.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Revert "f2fs: do not skip dentry block writes"

The periodic checkpoint can resolve the previous issue.
So, now we can use this again to improve the reported performance regression:

https://lkml.org/lkml/2015/10/8/20

This reverts commit 15bec0ff5a9ba6d203178fa8772259df6207942a.

f2fs: introduce background_gc=sync mount option

This patch introduce background_gc=sync enabling synchronous cleaning in
background.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not skip dentry block writes

Previously, we skip dentry block writes when wbc is SYNC_NONE with no memory
pressure and the number of dirty pages is pretty small.

But, we didn't skip for normal data writes, which gives us not much big impact
on overall performance.
Moreover, by skipping some data writes, kworker falls into infinite loop to try
to write blocks, when many dir inodes have only one dentry block.

So, this patch removes skipping data writes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid a build warning

If F2FS_CHECK_FS is turned off, we can get a build warning for unused variable.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove inmem radix tree

Previously, we use radix tree to index all registered page entries for
atomic file, but now we only use radix tree to see whether current page
is indexed or not, since the other user of radix tree is gone in commit
042b7816aaeb ("f2fs: remove unnecessary call to invalidate inmemory pages").

So in this patch, we try to use one more efficient way:
Introducing a macro ATOMIC_WRITTEN_PAGE, and setting it as page private
value to indicate page indexing status. By using this way, we can save
memory and lookup time.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: unify f2fs_bug_on when check blocks and segment

Replace BUG_ON with f2fs_bug_on to deal with
block and segment validity check failed.

Signed-off-by: Xue Liu <liuxueliu.liu@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

writeback: separate out include/linux/backing-dev-defs.h

With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it. c files
which need access to more backing-dev details now include
backing-dev.h directly. This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>

writeback: move bandwidth related fields from backing_dev_info into bdi_writeback

Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear. For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi. To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.

This patch moves bandwidth related fields from backing_dev_info into
bdi_writeback.

* The moved fields are: bw_time_stamp, dirtied_stamp, written_stamp,
write_bandwidth, avg_write_bandwidth, dirty_ratelimit,
balanced_dirty_ratelimit, completions and dirty_exceeded.

* writeback_chunk_size() and over_bground_thresh() now take @wb
instead of @bdi.

* bdi_writeout_fraction(bdi, ...) -> wb_writeout_fraction(wb, ...)
bdi_dirty_limit(bdi, ...) -> wb_dirty_limit(wb, ...)
bdi_position_ration(bdi, ...) -> wb_position_ratio(wb, ...)
bdi_update_writebandwidth(bdi, ...) -> wb_update_write_bandwidth(wb, ...)
[__]bdi_update_bandwidth(bdi, ...) -> [__]wb_update_bandwidth(wb, ...)
bdi_{max|min}_pause(bdi, ...) -> wb_{max|min}_pause(wb, ...)
bdi_dirty_limits(bdi, ...) -> wb_dirty_limits(wb, ...)

* Init/exits of the relocated fields are moved to bdi_wb_init/exit()
respectively. Note that explicit zeroing is dropped in the process
as wb's are cleared in entirety anyway.

* As there's still only one bdi_writeback per backing_dev_info, all
uses of bdi->stat[] are mechanically replaced with bdi->wb.stat[]
introducing no behavior changes.

v2: Typo in description fixed as suggested by Jan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

f2fs: introduce discard_map for f2fs_trim_fs

This patch adds a bitmap for discard issues from f2fs_trim_fs.
There-in rule is to issue discard commands only for invalidated blocks
after mount.
Once mount is done, f2fs_trim_fs trims out whole invalid area.
After ehn, it will not issue and discrads redundantly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reduce searching region of segmap when set free section

In __set_free we will check whether all segment are free in one section
when free one segment, in order to set section to free status. But the
searching region of segmap is from start segno to last segno of main
area, it's not necessary. So let's just only check all segment bitmap
of target section.

Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use spinlock for segmap_lock instead of rwlock

rwlock can provide better concurrency when there are much more readers than
writers because readers can hold the rwlock simultaneously.

But now, for segmap_lock rwlock in struct free_segmap_info, there is only one
reader 'mount' from below call path:
->f2fs_fill_super
->build_segment_manager
->build_dirty_segmap
->init_dirty_segmap
->find_next_inuse
read_lock
...
read_unlock

Now that our concurrency can not be improved since there is no other reader for
this lock, we do not need to use rwlock_t type for segmap_lock, let's replace it
with spinlock_t type.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid variable length array

Instead of using variable length array, this patch let preallocate memory for
them.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: merge flags in struct f2fs_sb_info

Currently, there are several variables with Boolean type as below:

struct f2fs_sb_info {
...
int s_dirty;
bool need_fsck;
bool s_closing;
...
bool por_doing;
...
}

For this there are some issues:
1. there are some space of f2fs_sb_info is wasted due to aligning after Boolean
type variables by compiler.
2. if we continuously add new flag into f2fs_sb_info, structure will be messed
up.

So in this patch, we try to:
1. switch s_dirty to Boolean type variable since it has two status 0/1.
2. merge s_dirty/need_fsck/s_closing/por_doing variables into s_flag.
3. introduce an enum type which can indicate different states of sbi.
4. use new introduced universal interfaces is_sbi_flag_set/{set,clear}_sbi_flag
to operate flags for sbi.

After that, above issues will be fixed.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not skip any writes under memory pressure

Under memory pressure, let's avoid skipping data writes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce f2fs_change_bit to simplify the change bit logic

Introduce f2fs_change_bit to simplify the change bit logic in
function set_to_next_nat{sit}.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support atomic writes

This patch introduces a very limited functionality for atomic write support.
In order to support atomic write, this patch adds two ioctls:
o F2FS_IOC_START_ATOMIC_WRITE
o F2FS_IOC_COMMIT_ATOMIC_WRITE

The database engine should be aware of the following sequence.
1. open
-> ioctl(F2FS_IOC_START_ATOMIC_WRITE);
2. writes
: all the written data will be treated as atomic pages.
3. commit
-> ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
: this flushes all the data blocks to the disk, which will be shown all or
nothing by f2fs recovery procedure.
4. repeat to #2.

The IO pattens should be:

,- START_ATOMIC_WRITE ,- COMMIT_ATOMIC_WRITE
CP | D D D D D D | FSYNC | D D D D | FSYNC ...
`- COMMIT_ATOMIC_WRITE

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: potential shift wrapping buf in f2fs_trim_fs()

My static checker complains that segment is a u64 but only the lower 31
bits can be used before we hit a shift wrapping bug.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check the use of macros on block counts and addresses

This patch cleans up the existing and new macros for readability.

Rule is like this.

,-----------------------------------------> MAX_BLKADDR -,
| ,------------- TOTAL_BLKS ----------------------------,
| | |
| ,- seg0_blkaddr ,----- sit/nat/ssa/main blkaddress |
block | | (SEG0_BLKADDR) | | | | (e.g., MAIN_BLKADDR) |
address 0..x................ a b c d .............................
| |
global seg# 0...................... m .............................
| | |
| `------- MAIN_SEGS -----------'
`-------------- TOTAL_SEGS ---------------------------'
| |
seg# 0..........xx..................

= Note =
o GET_SEGNO_FROM_SEG0 : blk address -> global segno
o GET_SEGNO : blk address -> segno
o START_BLOCK : segno -> starting block address

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use more free segments until SSR is activated

Previously, f2fs activates SSR if the # of free segments reaches to the # of
overprovisioned segments.
In this case, SSR starts to use dirty segments only, so that the overprovisoned
space cannot be selected for new data.
This means that we have no chance to utilizae the overprovisioned space at all.

This patch fixes that by allowing LFS allocations until the # of free segments
reaches to the last threshold, reserved space.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change the ipu_policy option to enable combinations

This patch changes the ipu_policy setting to use any combination of orthogonal policies.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support large sector size

Block size in f2fs is 4096 bytes, so theoretically, f2fs can support 4096 bytes
sector device at maximum. But now f2fs only support 512 bytes size sector, so
block device such as zRAM which uses page cache as its block storage space will
not be mounted successfully as mismatch between sector size of zRAM and sector
size of f2fs supported.

In this patch we support large sector size in f2fs, so block device with sector
size of 512/1024/2048/4096 bytes can be supported in f2fs.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use MAX_BIO_BLOCKS(sbi)

This patch cleans up a simple macro.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use meta_inode cache to improve roll-forward speed

Previously, all the dnode pages should be read during the roll-forward recovery.
Even worsely, whole the chain was traversed twice.
This patch removes that redundant and costly read operations by using page cache
of meta_inode and readahead function as well.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: give an option to enable in-place-updates during fsync to users

If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
only starts to try in-place-updates.
And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
keeps out-of-order manner. Otherwise, it triggers in-place-updates.

This may be used by storage showing very high random write performance.

For example, it can be used when,

Seq. writes (Data) + wait + Seq. writes (Node)

is pretty much slower than,

Rand. writes (Data)

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor flush_sit_entries codes for reducing SIT writes

In commit aec71382c681 ("f2fs: refactor flush_nat_entries codes for reducing NAT
writes"), we descripte the issue as below:

"Although building NAT journal in cursum reduce the read/write work for NAT
block, but previous design leave us lower performance when write checkpoint
frequently for these cases:
1. if journal in cursum has already full, it's a bit of waste that we flush all
nat entries to page for persistence, but not to cache any entries.
2. if journal in cursum is not full, we fill nat entries to journal util
journal is full, then flush the left dirty entries to disk without merge
journaled entries, so these journaled entries may be flushed to disk at next
checkpoint but lost chance to flushed last time."

Actually, we have the same problem in using SIT journal area.

In this patch, firstly we will update sit journal with dirty entries as many as
possible. Secondly if there is no space in sit journal, we will remove all
entries in journal and walk through the whole dirty entry bitmap of sit,
accounting dirty sit entries located in same SIT block to sit entry set. All
entry sets are linked to list sit_entry_set in sm_info, sorted ascending order
by count of entries in set. Later we flush entries in set which have fewest
entries into journal as many as we can, and then flush dense set with merged
entries to disk.

In this way we can use sit journal area more effectively, also we will reduce
SIT update, result in gaining in performance and saving lifetime of flash
device.

In my testing environment, it shows this patch can help to reduce SIT block
update obviously.

virtual machine + hard disk:
fsstress -p 20 -n 400 -l 5
sit page num cp count sit pages/cp
based 2006.50 1349.75 1.486
patched 1566.25 1463.25 1.070

Our latency of merging op is small when handling a great number of dirty SIT
entries in flush_sit_entries:
latency(ns) dirty sit count
36038 2151
49168 2123
37174 2232

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unneeded sit_i in macro SIT_BLOCK_OFFSET/START_SEGNO

sit_i in macro SIT_BLOCK_OFFSET/START_SEGNO is not used, remove it.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add BUG cases to initiate fsck.f2fs

This patch replaces BUG cases with f2fs_bug_on to remain fsck.f2fs information.
And it implements some void functions to initiate fsck.f2fs too.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce F2FS_I_SB, F2FS_M_SB, and F2FS_P_SB

This patch adds three inline functions to clean up dirty casting codes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix typo

Fix typo and some grammatical errors.

The words "filesystem" and "readahead" are being used without the space treewide.

Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enable in-place-update for fdatasync

This patch enforces in-place-updates only when fdatasync is requested.
If we adopt this in-place-updates for the fdatasync, we can skip to write the
recovery information.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reduce searching region of segmap when free section

In __set_test_and_free we will check whether all segment are free in one section
When free one segment, in order to set section to free status.
But the searching region of segmap is from start segno to last segno of f2fs,
it's not necessary. So let's just only check all segment bitmap of target
section.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change reclaim rate in percentage

It is more reasonable to determine the reclaiming rate of prefree segments
according to the volume size, which is set to 5% by default.
For example, if the volume is 128GB, the prefree segments are reclaimed
when the number reaches to 6.4GB.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce nr_pages_to_write for segment alignment

This patch introduces nr_pages_to_write to align page writes to the segment
or other operational unit size, which can be tuned according to the system
environment.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid small data writes by skipping writepages

This patch introduces nr_pages_to_skip(sbi, type) to determine writepages can
be skipped.
The dentry, node, and meta pages can be conrolled by F2FS without breaking the
FS consistency.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: implement a lock-free stat_show

The stat_show is just to show the current status of f2fs.
So, we can remove all the there-in locks.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean up with a macro

This patch adds GET_BLKOFF_FROM_SEG0 to clean up some codes.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clean checkpatch warnings

Fixed a variety of trivial checkpatch warnings. The only delta should
be some minor formatting on log strings that were split / too long.

Signed-off-by: Chris Fries <cfries@motorola.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce sysfs entry to control in-place-update policy

This patch introduces new sysfs entries for users to control the policy of
in-place-updates, namely IPU, in f2fs.

Sometimes f2fs suffers from performance degradation due to its out-of-place
update policy that produces many additional node block writes.
If the storage performance is very dependant on the amount of data writes
instead of IO patterns, we'd better drop this out-of-place update policy.

This patch suggests 5 polcies and their triggering conditions as follows.

[sysfs entry name = ipu_policy]

0: F2FS_IPU_FORCE all the time,
1: F2FS_IPU_SSR if SSR mode is activated,
2: F2FS_IPU_UTIL if FS utilization is over threashold,
3: F2FS_IPU_SSR_UTIL if SSR mode is activated and FS utilization is over
threashold,
4: F2FS_IPU_DISABLE disable IPU. (=default option)

[sysfs entry name = min_ipu_util]

This parameter controls the threshold to trigger in-place-updates.
The number indicates percentage of the filesystem utilization, and used by
F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.

For more details, see need_inplace_update() in segment.h.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add unlikely() macro for compiler optimization

As we know, some of our branch condition will rarely be true. So we could add
'unlikely' to let compiler optimize these code, by this way we could drop
unneeded 'jump' assemble code to improve performance.

change log:
o add *unlikely* as many as possible across the whole source files at once
suggested by Jaegeuk Kim.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: remove the own bi_private allocation

Previously f2fs allocates its own bi_private data structure all the time even
though we don't use it. But, can we remove this bi_private allocation?

This patch removes such the additional bi_private allocation.

1. Retrieve f2fs_sb_info from its page->mapping->host->i_sb.
- This removes the usecases of bi_private in end_io.

2. Use bi_private only when we really need it.
- The bi_private is used only when the checkpoint procedure is conducted.
- When conducting the checkpoint, f2fs submits a META_FLUSH bio to wait its bio
completion.
- Since we have no dependancies to remove bi_private now, let's just use
bi_private pointer as the completion pointer.

Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: correct type of wait in struct bio_private

The void *wait in bio_private is used for waiting completion of checkpoint bio.
So we don't need to use its type as void, but declare it as completion type.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: add description]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: bug fix on bit overflow from 32bits to 64bits

This patch fixes some bit overflows by the shift operations.

Dan Carpenter reported potential bugs on bit overflows as follows.

fs/f2fs/segment.c:910 submit_write_page()
warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/checkpoint.c:429 get_valid_checkpoint()
warn: should '1 << ()' be a 64 bit type?
fs/f2fs/data.c:408 f2fs_readpage()
warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/data.c:457 submit_read_page()
warn: should 'blk_addr << ((sbi)->log_blocksize - 9)' be a 64 bit type?
fs/f2fs/data.c:525 get_data_block_ro()
warn: should 'i << blkbits' be a 64 bit type?

Bug-Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: read contiguous sit entry pages by merging for mount performance

Previously we read sit entries page one by one, this method lost the chance
of reading contiguous page together. So we read pages as contiguous as
possible for better mount performance.

change log:
o merge judgements/use 'Continue' or 'Break' instead of 'Goto' as Gu Zheng
suggested.
o add mark_page_accessed() before release page to delay VM reclaiming.
o remove '*order' for simplification of function as Jaegeuk Kim suggested.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix a bug on the block address calculation]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: simplify IS_DATASEG and IS_NODESEG macro

It is not efficient comparing each segment type to find node or data.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
[Jaegeuk Kim: remove unnecessary white spaces]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: check all ones or zeros bitmap with bitops for better mount performance

Previously, check_block_count check valid_map with bit data type in common
scenario that sit has all ones or zeros bitmap, it makes low mount performance.
So let's check the special bitmap with integer data type instead of the bit one.

v1-->v2:
o use find_next_{zero_}bit_le for better performance and readable as Jaegeuk
suggested.
o use neat logogram in comment as Gu Zheng suggested.
o search continuous ones or zeros for better performance when checking mixed
bitmap.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add an option to avoid unnecessary BUG_ONs

If you want to remove unnecessary BUG_ONs, you can just turn off F2FS_CHECK_FS
in your kernel config.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: reclaim prefree segments periodically

Previously, f2fs postpones reclaiming prefree segments into free segments
as much as possible.
However, if user writes and deletes a bunch of data without any sync or fsync
calls, some flash storages can suffer from garbage collections.

So, this patch adds the reclaiming codes to f2fs_write_node_pages and background
GC thread.

If there are a lot of prefree segments, let's do checkpoint so that f2fs
submits discard commands for the prefree regions to the flash storage.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid allocating failure in bio_alloc

This patch add macro MAX_BIO_BLOCKS to limit value of npages in
f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused by
npages is larger than BIO_MAX_PAGES.

Signed-off-by: Yu Chao <chao2.yu@samsung.com>
Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: optimize gc for better performance

This patch improves the gc efficiency by optimizing the victim
selection policy. With this optimization, the random re-write
performance could increase up to 20%.

For f2fs, when disk is in shortage of free spaces, gc will selects
dirty segments and moves valid blocks around for making more space
available. The gc cost of a segment is determined by the valid blocks
in the segment. The less the valid blocks, the higher the efficiency.
The ideal victim segment is the one that has the most garbage blocks.

Currently, it searches up to 20 dirty segments for a victim segment.
The selected victim is not likely the best victim for gc when there
are much more dirty segments. Why not searching more dirty segments
for a better victim? The cost of searching dirty segments is
negligible in comparison to moving blocks.

In this patch, it enlarges the MAX_VICTIM_SEARCH to 4096 to make
the search more aggressively for a possible better victim. Since
it also applies to victim selection for SSR, it will likely improve
the SSR efficiency as well.

The test case is simple. It creates as many files until the disk full.
The size for each file is 32KB. Then it writes as many as 100000
records of 4KB size to random offsets of random files in sync mode.
The testing was done on a 2GB partition of a SDHC card. Let's see the
test result of f2fs without and with the patch.

---------------------------------------
2GB partition, SDHC
create 52023 files of size 32768 bytes
random re-write 100000 records of 4KB
---------------------------------------
| file creation (s) | rewrite time (s) | gc count | gc garbage blocks |
[no patch] 341 4227 1174 174840
[patched] 324 2958 645 106682

It's obvious that, with the patch, f2fs finishes the test in 20+% less
time than without the patch. And internally it does much less gc with
higher efficiency than before.

Since the performance improvement is related to gc, it might not be so
obvious for other tests that do not trigger gc as often as this one (
This is because f2fs selects dirty segments for SSR use most of the
time when free space is in shortage). The well-known iozone test tool
was not used for benchmarking the patch becuase it seems do not have
a test case that performs random re-write on a full disk.

This patch is the revised version based on the suggestion from
Jaegeuk Kim.

Signed-off-by: Jin Xu <jinuxstyle@gmail.com>
[Jaegeuk Kim: suggested simpler solution]
Reviewed-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: avoid an overflow during utilization calculation

The current f2fs uses all the block counts with 32 bit numbers, which is able to
cover about 15TB volume.

But in calculation of utilization, f2fs multiplies the count by 100 which can
induce overflow.
This patch fixes this.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: trigger GC when there are prefree segments

Previously, f2fs conducts SSR when free_sections() < overprovision_sections.
But, even though there are a lot of prefree segments, it can consider SSR only.
So, let's consider the number of prefree segments too for triggering SSR.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: modify the number of issued pages to merge IOs

When testing f2fs on an SSD, I found some 128 page IOs followed by 1 page IO
were issued by f2fs_write_node_pages.
This means that there were some mishandling flows which degrades performance.

Previous f2fs_write_node_pages determines the number of pages to be written,
nr_to_write, as follows.

1. The bio_get_nr_vecs returns 129 pages.
2. The bio_alloc makes a room for 128 pages.
3. The initial 128 pages go into one bio.
4. The existing bio is submitted, and a new bio is prepared for the last 1 page.
5. Finally, sync_node_pages submits the last 1 page bio.

The problem is from the use of bio_get_nr_vecs, so this patch replace it
with max_hw_blocks using queue_max_sectors.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix typo mistakes

Fix typo mistakes.
1. I think that it should be 'L' instead of 'V'.
2. and try to fix 'Front' instead of 'Frone'

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: change GC bitmaps to apply the section granularity

This patch removes a bitmap for victim segments selected by foreground GC, and
modifies the other bitmap for victim segments selected by background GC.

1) foreground GC bitmap
: We don't need to manage this, since we just only one previous victim section
number instead of the whole victim history.
The f2fs uses the victim section number in order not to allocate currently
GC'ed section to current active logs.

2) background GC bitmap
: This bitmap is used to avoid selecting victims repeatedly by background GCs.
In addition, the victims are able to be selected by foreground GCs, since
there is no need to read victim blocks during foreground GCs.

By the fact that the foreground GC reclaims segments in a section unit, it'd
be better to manage this bitmap based on the section granularity.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: introduce TOTAL_SECS macro

Let's use a macro to get the total number of sections.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: do not use duplicate names in a macro

A macro should not use duplicate parameter names.

Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix overflow when calculating utilization on 32-bit

Use div_u64 to fix overflow when calculating utilization.
*long int* is 4-bytes on 32-bit so (user blocks * 100) might be
overflow if disk size is over e.g. 512GB.

Signed-off-by: Changman Lee <cm224.lee@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: clarify and enhance the f2fs_gc flow

This patch makes clearer the ambiguous f2fs_gc flow as follows.

1. Remove intermediate checkpoint condition during f2fs_gc
(i.e., should_do_checkpoint() and GC_BLOCKED)

2. Remove unnecessary return values of f2fs_gc because of #1.
(i.e., GC_NODE, GC_OK, etc)

3. Simplify write_checkpoint() because of #2.

4. Clarify the main f2fs_gc flow.
o monitor how many freed sections during one iteration of do_garbage_collect().
o do GC more without checkpoints if we can't get enough free sections.
o do checkpoint once we've got enough free sections through forground GCs.

5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data
log types. See. get_ssr_segement()

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: optimize the return condition for has_not_enough_free_secs

Instead of evaluating the free_sections and then deciding to return
true/false from that path. We can directly use the evaluation condition
for returning proper value.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: make an accessor to get sections for particular block type

Introduce accessor to get the sections based upon the block type
(node,dents...) and modify the functions : should_do_checkpoint,
has_not_enough_free_secs to use this accessor function to get
the node sections and dent sections.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: fix equation of has_not_enough_free_secs()

Practically, has_not_enough_free_secs() should calculate with the numbers of
current node and directory data blocks together.
Actually the equation was implemented in need_to_flush().

So, this patch removes need_flush() and moves the equation into
has_not_enough_free_secs().

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: cleanup the f2fs_bio_alloc routine

Do cleanup more for better code readability.

- Change the parameter set of f2fs_bio_alloc()
This function should allocate a bio only since it is not something like
f2fs_bio_init(). Instead, the caller should initialize the allocated bio.

- Introduce SECTOR_FROM_BLOCK
This macro translates a block address to its sector address.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>

f2fs: adjust kernel coding style

As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment
blocks. Instead, just use "/*".

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

f2fs: add superblock and major in-memory structure

This adds the following major in-memory structures in f2fs.

- f2fs_sb_info:
contains f2fs-specific information, two special inode pointers for node and
meta address spaces, and orphan inode management.

- f2fs_inode_info:
contains vfs_inode and other fs-specific information.

- f2fs_nm_info:
contains node manager information such as NAT entry cache, free nid list,
and NAT page management.

- f2fs_node_info:
represents a node as node id, inode number, block address, and its version.

- f2fs_sm_info:
contains segment manager information such as SIT entry cache, free segment
map, current active logs, dirty segment management, and segment utilization.
The specific structures are sit_info, free_segmap_info, dirty_seglist_info,
curseg_info.

In addition, add F2FS_SUPER_MAGIC in magic.h.

Signed-off-by: Chul Lee <chur.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>