f2fs: add a proc entry show disk layout

This patch adds the disk map of block address ranges configured by multiple
partitions.

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

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: 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: show more discard status by sysfs

The current pending_discard attr just only shows the discard_cmd_cnt
information. More discard status can be shown so that we can check
them through sysfs when needed.

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Constrain the modification range of dir_level in the sysfs

The {struct f2fs_sb_info}->dir_level can be modified through the sysfs
interface, but its value range is not limited. If the value exceeds
MAX_DIR_HASH_DEPTH and the mount options include "noinline_dentry",
the following error will occur:
[root@fedora ~]# mount -o noinline_dentry /dev/sdb /mnt/sdb/
[root@fedora ~]# echo 128 > /sys/fs/f2fs/sdb/dir_level
[root@fedora ~]# cd /mnt/sdb/
[root@fedora sdb]# mkdir test
[root@fedora sdb]# cd test/
[root@fedora test]# mkdir test
mkdir: cannot create directory 'test': Argument list too long

Signed-off-by: Yongpeng Yang <yangyongpeng1@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: sysfs: support discard_io_aware

It gives a way to enable/disable IO aware feature for background
discard, so that we can tune background discard more precisely
based on undiscard condition. e.g. force to disable IO aware if
there are large number of discard extents, and discard IO may
always be interrupted by frequent common IO.

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

f2fs: fix to account cp stats correctly

cp_foreground_calls sysfs entry shows total CP call count rather than
foreground CP call count, fix it.

Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to account gc stats correctly

As reported, status debugfs entry shows inconsistent GC stats as below:

GC calls: 6008 (BG: 6161)
- data segments : 3053 (BG: 3053)
- node segments : 2955 (BG: 2955)

Total GC calls is larger than BGGC calls, the reason is:
- f2fs_stat_info.call_count accounts total migrated section count
by f2fs_gc()
- f2fs_stat_info.bg_gc accounts total call times of f2fs_gc() from
background gc_thread

Another issue is gc_foreground_calls sysfs entry shows total GC call
count rather than FGGC call count.

This patch changes as below for fix:
- account GC calls and migrated segment count separately
- support to account migrated section count if it enables large section
mode
- fix to show correct value in gc_foreground_calls sysfs entry

Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: refactor struct f2fs_attr macro

This patch provides a large number of variants of F2FS_RW_ATTR
and F2FS_RO_ATTR macros, reducing the number of parameters required
to initialize the f2fs_attr structure.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202304152234.wjaY3IYm-lkp@intel.com/
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 sanity check for proc_mkdir

Return -ENOMEM when proc_mkdir failed.

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: remove bulk remove_proc_entry() and unnecessary kobject_del()

Convert to use remove_proc_subtree() and kill kobject_del() directly.
kobject_put() actually covers kobject removal automatically, which is
single stage removal.

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: convert to use sysfs_emit

Let's use sysfs_emit.

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 iostat lock protection

Made iostat lock irq safe to avoid potentinal deadlock.

Deadlock scenario:
f2fs_attr_store
-> f2fs_sbi_store
-> _sbi_store
-> spin_lock(sbi->iostat_lock)
<interrupt request>
-> scsi_end_request
-> bio_endio
-> f2fs_dio_read_end_io
-> f2fs_update_iostat
-> spin_lock_irqsave(sbi->iostat_lock) ===> Dead lock here

Fixes: 61803e984307 ("f2fs: fix iostat related lock protection")
Fixes: a1e09b03e6f5 ("f2fs: use iomap for direct I/O")
Signed-off-by: Qilin Tan <qilin.tan@mediatek.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: convert to use bitmap API

Let's use BIT() and GENMASK() instead of open it.

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: export compress_percent and compress_watermark entries

This patch export below sysfs entries for better control cached
compress page count.

/sys/fs/f2fs/<disk>/compress_watermark
/sys/fs/f2fs/<disk>/compress_percent

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: make kobj_type structures constant

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definitions to prevent
modification at runtime.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
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 sysfs nodes to set last_age_weight

Signed-off-by: qixiaoyu1 <qixiaoyu1@xiaomi.com>
Signed-off-by: xiongping1 <xiongping1@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to check warm_data_age_threshold

hot_data_age_threshold is a non-zero positive number, and
condition 2 includes condition 1, so there is no need to
additionally judge whether t is 0. And let's remove it.

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

f2fs: introduce discard_io_aware_gran sysfs node

The current discard_io_aware_gran is a fixed value, change it to be
configurable through the sys node.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
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: fix some format WARNING in debug.c and sysfs.c

To fix:

WARNING: function definition argument 'struct f2fs_attr *' should also have an identifier name
+ ssize_t (*show)(struct f2fs_attr *, struct f2fs_sb_info *, char *);

WARNING: return sysfs_emit(...) formats should include a terminating newline
+ return sysfs_emit(buf, "(none)");

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
+ unsigned npages = NODE_MAPPING(sbi)->nrpages;

WARNING: Missing a blank line after declarations
+ unsigned npages = COMPRESS_MAPPING(sbi)->nrpages;
+ si->page_mem += (unsigned long long)npages << PAGE_SHIFT;

WARNING: quoted string split across lines
+ seq_printf(s, "CP merge (Queued: %4d, Issued: %4d, Total: %4d, "
+ "Cur time: %4d(ms), Peak time: %4d(ms))\n",

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

f2fs: add block_age-based extent cache

This patch introduces a runtime hot/cold data separation method
for f2fs, in order to improve the accuracy for data temperature
classification, reduce the garbage collection overhead after
long-term data updates.

Enhanced hot/cold data separation can record data block update
frequency as "age" of the extent per inode, and take use of the age
info to indicate better temperature type for data block allocation:
- It records total data blocks allocated since mount;
- When file extent has been updated, it calculate the count of data
blocks allocated since last update as the age of the extent;
- Before the data block allocated, it searches for the age info and
chooses the suitable segment for allocation.

Test and result:
- Prepare: create about 30000 files
* 3% for cold files (with cold file extension like .apk, from 3M to 10M)
* 50% for warm files (with random file extension like .FcDxq, from 1K
to 4M)
* 47% for hot files (with hot file extension like .db, from 1K to 256K)
- create(5%)/random update(90%)/delete(5%) the files
* total write amount is about 70G
* fsync will be called for .db files, and buffered write will be used
for other files

The storage of test device is large enough(128G) so that it will not
switch to SSR mode during the test.

Benefit: dirty segment count increment reduce about 14%
- before: Dirty +21110
- after: Dirty +18286

Signed-off-by: qixiaoyu1 <qixiaoyu1@xiaomi.com>
Signed-off-by: xiongping1 <xiongping1@xiaomi.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce discard_urgent_util sysfs node

Through this node, you can control the background discard
to run more aggressively or not aggressively when reach the
utilization rate of the space.

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: change type for 'sbi->readdir_ra'

Before this patch, the varibale 'readdir_ra' takes effect if it's equal
to '1' or not, so we can change type for it from 'int' to 'bool'.

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

f2fs: add proc entry to show discard_plist info

This patch adds a new proc entry to show discard_plist
information in more detail, which is very helpful to
know the discard pend list count clearly.

Such as:

Discard pend list(Show diacrd_cmd count on each entry, .:not exist):
0 390 156 85 67 46 37 26 14
8 17 12 9 9 6 12 11 10
16 5 9 2 4 8 3 4 1
24 3 2 2 5 2 4 5 4
32 3 3 2 3 . 3 3 1
40 . 4 1 3 2 1 2 1
48 1 . 1 1 . 1 1 .
56 . 1 1 1 . 2 . 1
64 1 2 . . . . . .
72 . 1 . . . . . .
80 3 1 . . 1 1 . .
88 1 . . . 1 . . 1
......

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

f2fs: replace gc_urgent_high_remaining with gc_remaining_trials

The user can set the trial count limit for GC urgent and
idle mode with replaced gc_remaining_trials.. If GC thread gets
to the limit, the mode will turn back to GC normal mode finally.

It was applied only to GC_URGENT, while this patch expands it for
GC_IDLE.

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

f2fs: use sysfs_emit instead of sprintf

Let's use sysfs_emit.

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

f2fs: introduce gc_mode sysfs node

Revert "f2fs: make gc_urgent and gc_segment_mode sysfs node readable".

Add a gc_mode sysfs node to show the current gc_mode as a string.

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

f2fs: introduce max_ordered_discard sysfs node

The current max_ordered_discard is a fixed value, change it to be
configurable through the sys node.

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: remove batched_trim_sections node

commit 377224c47118("f2fs: don't split checkpoint in fstrim") obsolete
batch mode and related sysfs entry.

Since this testing sysfs node has been deprecated for a long time, let's
remove it.

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 cp_status sysfs entry

This patch adds a new sysfs entry named cp_status, it can output
checkpoint flags in real time.

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

f2fs: remove gc_urgent_high_limited for cleanup

Remove redundant sbi->gc_urgent_high_limited.

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

f2fs: introduce sysfs atomic write statistics

introduce the below 4 new sysfs node for atomic write statistics.
- current_atomic_write: the total current atomic write block count,
which is not committed yet.
- peak_atomic_write: the peak value of total current atomic write block
count after boot.
- committed_atomic_block: the accumulated total committed atomic write
block count after boot.
- revoked_atomic_block: the accumulated total revoked atomic write block
count after boot.

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

f2fs: add a sysfs entry to show zone capacity

This patch adds a sysfs entry showing the unusable space in a section
made by zone capacity.

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

f2fs: make gc_urgent and gc_segment_mode sysfs node readable

Changed a way of showing values of them to use strings.

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

f2fs: introduce gc_urgent_mid mode

We need a mid level of gc urgent mode to do GC forcibly in a period
of given gc_urgent_sleep_time, but not like using greedy GC approach
and switching to SSR mode such as gc urgent high mode. This can be
used for more aggressive periodic storage clean up.

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

f2fs: add a way to limit roll forward recovery time

This adds a sysfs entry to call checkpoint during fsync() in order to avoid
long elapsed time to run roll-forward recovery when booting the device.
Default value doesn't enforce the limitation which is same as before.

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

f2fs: expose discard related parameters in sysfs

This patch exposes max_discard_request, min_discard_issue_time,
mid_discard_issue_time, and max_discard_issue_time in sysfs. This will
allow the user to fine tune discard operations.

Signed-off-by: Konstantin Vyshetsky <vkon@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to enable ATGC correctly via gc_idle sysfs interface

It needs to assign sbi->gc_mode with GC_IDLE_AT rather than GC_AT when
user tries to enable ATGC via gc_idle sysfs interface, fix it.

Fixes: 093749e296e2 ("f2fs: support age threshold based garbage collection")
Cc: Zhipeng Tan <tanzhipeng@hust.edu.cn>
Signed-off-by: Jicheng Shao <shaojicheng@hust.edu.cn>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: move f2fs to use reader-unfair rwsems

f2fs rw_semaphores work better if writers can starve readers,
especially for the checkpoint thread, because writers are strictly
more important than reader threads. This prevents significant priority
inversion between low-priority readers that blocked while trying to
acquire the read lock and a second acquisition of the write lock that
might be blocking high priority work.

Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

unicode: clean up the Kconfig symbol confusion

Turn the CONFIG_UNICODE symbol into a tristate that generates some always
built in code and remove the confusing CONFIG_UNICODE_UTF8_DATA symbol.

Note that a lot of the IS_ENABLED() checks could be turned from cpp
statements into normal ifs, but this change is intended to be fairly
mechanic, so that should be cleaned up later.

Fixes: 2b3d04787012 ("unicode: Add utf8-data module")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

f2fs: Simplify bool conversion

Fix the following coccicheck warning:
./fs/f2fs/sysfs.c:491:41-46: WARNING: conversion to bool not needed here

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
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: add gc_urgent_high_remaining sysfs node

Added a new sysfs node called gc_urgent_high_remaining. The user can
set the trial count limit for GC urgent high mode with this value. If
GC thread gets to the limit, the mode will turn back to GC normal mode.
By default, the value is zero, which means there is no limit like before.

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

f2fs: show number of pending discard commands

This information can be used to check how much time we need to give to issue
all the discard commands.

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

unicode: remove the charset field from struct unicode_map

It is hardcoded and only used for a f2fs sysfs file where it can be
hardcoded just as easily.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>

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: replace snprintf in show functions with sysfs_emit

coccicheck complains about the use of snprintf() in sysfs show functions.

Fix the following coccicheck warning:
fs/f2fs/sysfs.c:198:12-20: WARNING: use scnprintf or sprintf.
fs/f2fs/sysfs.c:247:8-16: WARNING: use scnprintf or sprintf.

Use sysfs_emit instead of scnprintf or sprintf makes more sense.

Signed-off-by: Qing Wang <wangqing@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: separate out iostat feature

Added F2FS_IOSTAT config option to support getting IO statistics through
sysfs and printing out periodic IO statistics tracepoint events and
moved I/O statistics related codes into separate files for better
maintenance.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: set default=y]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: convert S_IRUGO to 0444

To fix:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'.

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 sysfs node to control ra_pages for fadvise seq file

fadvise() allows the user to expand the readahead window to double with
POSIX_FADV_SEQUENTIAL, now. But, in some use cases, it is not that
sufficient and we need to meet the need in a restricted way. We can
control the multiplier value of bdi device readahead between 2 (default)
and 256 for POSIX_FADV_SEQUENTIAL advise option.

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

f2fs: introduce discard_unit mount option

As James Z reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=213877

[1.] One-line summary of the problem:
Mount multiple SMR block devices exceed certain number cause system non-response

[2.] Full description of the problem/report:
Created some F2FS on SMR devices (mkfs.f2fs -m), then mounted in sequence. Each device is the same Model: HGST HSH721414AL (Size 14TB).
Empirically, found that when the amount of SMR device * 1.5Gb > System RAM, the system ran out of memory and hung. No dmesg output. For example, 24 SMR Disk need 24*1.5GB = 36GB. A system with 32G RAM can only mount 21 devices, the 22nd device will be a reproducible cause of system hang.
The number of SMR devices with other FS mounted on this system does not interfere with the result above.

[3.] Keywords (i.e., modules, networking, kernel):
F2FS, SMR, Memory

[4.] Kernel information
[4.1.] Kernel version (uname -a):
Linux 5.13.4-200.fc34.x86_64 #1 SMP Tue Jul 20 20:27:29 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

[4.2.] Kernel .config file:
Default Fedora 34 with f2fs-tools-1.14.0-2.fc34.x86_64

[5.] Most recent kernel version which did not have the bug:
None

[6.] Output of Oops.. message (if applicable) with symbolic information
resolved (see Documentation/admin-guide/oops-tracing.rst)
None

[7.] A small shell script or example program which triggers the
problem (if possible)
mount /dev/sdX /mnt/0X

[8.] Memory consumption

With 24 * 14T SMR Block device with F2FS
free -g
total used free shared buff/cache available
Mem: 46 36 0 0 10 10
Swap: 0 0 0

With 3 * 14T SMR Block device with F2FS
free -g
total used free shared buff/cache available
Mem: 7 5 0 0 1 1
Swap: 7 0 7

The root cause is, there are three bitmaps:
- cur_valid_map
- ckpt_valid_map
- discard_map
and each of them will cost ~500MB memory, {cur, ckpt}_valid_map are
necessary, but discard_map is optional, since this bitmap will only be
useful in mountpoint that small discard is enabled.

For a blkzoned device such as SMR or ZNS devices, f2fs will only issue
discard for a section(zone) when all blocks of that section are invalid,
so, for such device, we don't need small discard functionality at all.

This patch introduces a new mountoption "discard_unit=block|segment|
section" to support issuing discard with different basic unit which is
aligned to block, segment or section, so that user can specify
"discard_unit=segment" or "discard_unit=section" to disable small
discard functionality.

Note that this mount option can not be changed by remount() due to
related metadata need to be initialized during mount().

In order to save memory, let's use "discard_unit=section" for blkzoned
device by default.

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

f2fs: avoid to create an empty string as the extension_list

When creating a file, we need to set the temperature based on
extension_list. If the empty string is a valid extension_list,
the is_extension_exist will always returns true,
which affects the separation of hot and cold.

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

f2fs: add sysfs nodes to get GC info for each GC mode

Added gc_reclaimed_segments and gc_segment_mode sysfs nodes.
1) "gc_reclaimed_segments" shows how many segments have been
reclaimed by GC during a specific GC mode.
2) "gc_segment_mode" is used to control for which gc mode
the "gc_reclaimed_segments" node shows.

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

block: Introduce IOPRIO_NR_LEVELS

The BFQ scheduler and ioprio_check_cap() both assume that the RT
priority class (IOPRIO_CLASS_RT) can have up to 8 different priority
levels, similarly to the BE class (IOPRIO_CLASS_iBE). This is
controlled using the IOPRIO_BE_NR macro , which is badly named as the
number of levels also applies to the RT class.

Introduce the class independent IOPRIO_NR_LEVELS macro, defined to 8,
to make things clear. Keep the old IOPRIO_BE_NR macro definition as an
alias for IOPRIO_NR_LEVELS.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Link: https://lore.kernel.org/r/20210811033702.368488-6-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

f2fs: clean up /sys/fs/f2fs/<disk>/features

Let's create /sys/fs/f2fs/<disk>/feature_list/ to meet sysfs rule.

Note that there are three feature list entries:
1) /sys/fs/f2fs/features
: shows runtime features supported by in-kernel f2fs along with Kconfig.
- ref. F2FS_FEATURE_RO_ATTR()

2) /sys/fs/f2fs/$s_id/features <deprecated>
: shows on-disk features enabled by mkfs.f2fs, used for old kernels. This
won't add new feature anymore, and thus, users should check entries in 3)
instead of this 2).

3) /sys/fs/f2fs/$s_id/feature_list
: shows on-disk features enabled by mkfs.f2fs per instance, which follows
sysfs entry rule where each entry should expose single value.
This list covers old feature list provided by 2) and beyond. Therefore,
please add new on-disk feature in this list only.
- ref. F2FS_SB_FEATURE_RO_ATTR()

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

f2fs: add pin_file in feature list

This patch adds missing pin_file feature supported by kernel.

Fixes: f5a53edcf01e ("f2fs: support aligned pinned file")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Advertise encrypted casefolding in sysfs

Older kernels don't support encryption with casefolding. This adds
the sysfs entry encrypted_casefold to show support for those combined
features. Support for this feature was originally added by
commit 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")

Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption")
Cc: stable@vger.kernel.org # v5.11+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Show casefolding support only when supported

The casefolding feature is only supported when CONFIG_UNICODE is set.
This modifies the feature list f2fs presents under sysfs accordingly.

Fixes: 5aba54302a46 ("f2fs: include charset encoding information in the superblock")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support RO feature

Given RO feature in superblock, we don't need to check provisioning/reserve
spaces and SSA area.

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

f2fs: atgc: export entries for better tunability via sysfs

This patch export below sysfs entries for better ATGC tunability.

/sys/fs/f2fs/<disk>/atgc_candidate_ratio
/sys/fs/f2fs/<disk>/atgc_candidate_count
/sys/fs/f2fs/<disk>/atgc_age_weight
/sys/fs/f2fs/<disk>/atgc_age_threshold

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

f2fs: add sysfs nodes to get runtime compression stat

I've added new sysfs nodes to show runtime compression stat since mount.
compr_written_block - show the block count written after compression
compr_saved_block - show the saved block count with compression
compr_new_inode - show the count of inode newly enabled for compression

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

f2fs: expose # of overprivision segments

This is useful when checking conditions during checkpoint=disable in Android.

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

f2fs: add ckpt_thread_ioprio sysfs node

Added "ckpt_thread_ioprio" sysfs node to give a way to change checkpoint
merge daemon's io priority. Its default value is "be,3", which means
"BE" I/O class and I/O priority "3". We can select the class between "rt"
and "be", and set the I/O priority within valid range of it.
"," delimiter is necessary in between I/O class and priority number.

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

f2fs: introduce sb_status sysfs node

Introduce /sys/fs/f2fs/<devname>/stat/sb_status to show superblock
status in real time as a hexadecimal value.

value sb status macro description

0x1 SBI_IS_DIRTY, /* dirty flag for checkpoint */
0x2 SBI_IS_CLOSE, /* specify unmounting */
0x4 SBI_NEED_FSCK, /* need fsck.f2fs to fix */
0x8 SBI_POR_DOING, /* recovery is doing or not */
0x10 SBI_NEED_SB_WRITE, /* need to recover superblock */
0x20 SBI_NEED_CP, /* need to checkpoint */
0x40 SBI_IS_SHUTDOWN, /* shutdown by ioctl */
0x80 SBI_IS_RECOVERED, /* recovered orphan/data */
0x100 SBI_CP_DISABLED, /* CP was disabled last mount */
0x200 SBI_CP_DISABLED_QUICK, /* CP was disabled quickly */
0x400 SBI_QUOTA_NEED_FLUSH, /* need to flush quota info in CP */
0x800 SBI_QUOTA_SKIP_FLUSH, /* skip flushing quota in current CP */
0x1000 SBI_QUOTA_NEED_REPAIR, /* quota file may be corrupted */
0x2000 SBI_IS_RESIZEFS, /* resizefs is in process */

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

f2fs: introduce a new per-sb directory in sysfs

Add a new directory 'stat' in path of /sys/fs/f2fs/<devname>/, later
we can add new readonly stat sysfs file into this directory, it will
make <devname> directory less mess.

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

f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size

This patch adds max_io_bytes to limit bio size when f2fs tries to merge
consecutive IOs. This can give a testing point to split out bios and check
end_io handles those bios correctly. This is used to capture a recent bug
on the decompression and fsverity flow.

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

f2fs: fix kbytes written stat for multi-device case

For multi-device case, one f2fs image includes multi devices, so it
needs to account bytes written of all block devices belong to the image
rather than one main block device, fix it.

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

f2fs: remove a few bd_part checks

bd_part is never NULL for a block device in use by a file system, so
remove the checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info

syzkaller found that with CONFIG_DEBUG_KOBJECT_RELEASE=y, unmounting an
f2fs filesystem could result in the following splat:

kobject: 'loop5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 250)
kobject: 'f2fs_xattr_entry-7:5' ((____ptrval____)): kobject_release, parent 0000000000000000 (delayed 750)
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x98
WARNING: CPU: 0 PID: 699 at lib/debugobjects.c:485 debug_print_object+0x180/0x240
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 699 Comm: syz-executor.5 Tainted: G S 5.9.0-rc8+ #101
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x4d8
show_stack+0x34/0x48
dump_stack+0x174/0x1f8
panic+0x360/0x7a0
__warn+0x244/0x2ec
report_bug+0x240/0x398
bug_handler+0x50/0xc0
call_break_hook+0x160/0x1d8
brk_handler+0x30/0xc0
do_debug_exception+0x184/0x340
el1_dbg+0x48/0xb0
el1_sync_handler+0x170/0x1c8
el1_sync+0x80/0x100
debug_print_object+0x180/0x240
debug_check_no_obj_freed+0x200/0x430
slab_free_freelist_hook+0x190/0x210
kfree+0x13c/0x460
f2fs_put_super+0x624/0xa58
generic_shutdown_super+0x120/0x300
kill_block_super+0x94/0xf8
kill_f2fs_super+0x244/0x308
deactivate_locked_super+0x104/0x150
deactivate_super+0x118/0x148
cleanup_mnt+0x27c/0x3c0
__cleanup_mnt+0x28/0x38
task_work_run+0x10c/0x248
do_notify_resume+0x9d4/0x1188
work_pending+0x8/0x34c

Like the error handling for f2fs_register_sysfs(), we need to wait for
the kobject to be destroyed before returning to prevent a potential
use-after-free.

Fixes: bf9e697ecd42 ("f2fs: expose features to sysfs entry")
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Signed-off-by: Jamie Iles <jamie@nuviainc.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: Use generic casefolding support

This switches f2fs over to the generic support provided in
the previous patch.

Since casefolded dentries behave the same in ext4 and f2fs, we decrease
the maintenance burden by unifying them, and any optimizations will
immediately apply to both.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: space related cleanup

Just for code style, no logic change
1. delete useless space
2. change spaces into tab

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: remove write attribute of main_blkaddr sysfs node

Fuzzing main_blkaddr sysfs node will corrupt this field's value,
causing kernel panic, remove its write attribute to avoid potential
security risk.

[Chao Yu: add description]

Signed-off-by: Dehe Gu <gudehe@huawei.com>
Signed-off-by: Daiyue Zhang <zhangdaiyue1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add GC_URGENT_LOW mode in gc_urgent

Added a new gc_urgent mode, GC_URGENT_LOW, in which mode
F2FS will lower the bar of checking idle in order to
process outstanding discard commands and GC a little bit
aggressively.

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

f2fs: add node_io_flag for bio flags likewise data_io_flag

This patch adds another way to attach bio flags to node writes.

Description: Give a way to attach REQ_META|FUA to node writes
given temperature-based bits. Now the bits indicate:
* REQ_META | REQ_FUA |
* 5 | 4 | 3 | 2 | 1 | 0 |
* Cold | Warm | Hot | Cold | Warm | Hot |

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

fscrypt: support test_dummy_encryption=v2

v1 encryption policies are deprecated in favor of v2, and some new
features (e.g. encryption+casefolding) are only being added for v2.

Therefore, the "test_dummy_encryption" mount option (which is used for
encryption I/O testing with xfstests) needs to support v2 policies.

To do this, extend its syntax to be "test_dummy_encryption=v1" or
"test_dummy_encryption=v2". The existing "test_dummy_encryption" (no
argument) also continues to be accepted, to specify the default setting
-- currently v1, but the next patch changes it to v2.

To cleanly support both v1 and v2 while also making it easy to support
specifying other encryption settings in the future (say, accepting
"$contents_mode:$filenames_mode:v2"), make ext4 and f2fs maintain a
pointer to the dummy fscrypt_context rather than using mount flags.

To avoid concurrency issues, don't allow test_dummy_encryption to be set
or changed during a remount. (The former restriction is new, but
xfstests doesn't run into it, so no one should notice.)

Tested with 'gce-xfstests -c {ext4,f2fs}/encrypt -g auto'. On ext4,
there are two regressions, both of which are test bugs: ext4/023 and
ext4/028 fail because they set an xattr and expect it to be stored
inline, but the increase in size of the fscrypt_context from
24 to 40 bytes causes this xattr to be spilled into an external block.

Link: https://lore.kernel.org/r/20200512233251.118314-4-ebiggers@kernel.org
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>

f2fs: add compressed/gc data read IO stat

in order to account data read IOs more accurately.

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

f2fs: support read iostat

Adds to support accounting read IOs from userspace/kernel.

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

f2fs: add tracepoint for f2fs iostat

Added a tracepoint to see iostat of f2fs. Default period of that
is 3 second. This tracepoint can be used to be monitoring
I/O statistics periodically.

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

f2fs: introduce sysfs/data_io_flag to attach REQ_META/FUA

This patch introduces a way to attach REQ_META/FUA explicitly
to all the data writes given temperature.

-> attach REQ_FUA to Hot Data writes

-> attach REQ_FUA to Hot|Warm Data writes

-> attach REQ_FUA to Hot|Warm|Cold Data writes

-> attach REQ_FUA to Hot|Warm|Cold Data writes as well as
REQ_META to Hot Data writes

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

f2fs: add missing CONFIG_F2FS_FS_COMPRESSION

Compression sysfs node should not be shown if f2fs module disables
compression feature.

Signed-off-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: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit. Fix it by replacing with scnprintf().

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

f2fs: Add f2fs stats to sysfs

Currently f2fs stats are only available from /d/f2fs/status. This patch
adds some of the f2fs stats to sysfs so that they are accessible even
when debugfs is not mounted.

The following sysfs nodes are added:
-/sys/fs/f2fs/<disk>/free_segments
-/sys/fs/f2fs/<disk>/cp_foreground_calls
-/sys/fs/f2fs/<disk>/cp_background_calls
-/sys/fs/f2fs/<disk>/gc_foreground_calls
-/sys/fs/f2fs/<disk>/gc_background_calls
-/sys/fs/f2fs/<disk>/moved_blocks_foreground
-/sys/fs/f2fs/<disk>/moved_blocks_background
-/sys/fs/f2fs/<disk>/avg_vblocks

Signed-off-by: Hridya Valsaraju <hridya@google.com>
[Jaegeuk Kim: allow STAT_FS without DEBUG_FS]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix memleak of kobject

If kobject_init_and_add() failed, caller needs to invoke kobject_put()
to release kobject explicitly.

Signed-off-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: free sysfs kobject

Detected kmemleak.

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

f2fs: expose main_blkaddr in sysfs

Expose in /sys/fs/f2fs/<blockdev>/main_blkaddr the block address where the
main area starts. This allows user mode programs to determine:

- That pinned files that are made exclusively of fully allocated 2MB
segments will never be unpinned by the file system.

- Where the main area starts. This is required by programs that want to
verify if a file is made exclusively of 2MB f2fs segments, the alignment
boundary for segments starts at this address. Testing for 2MB alignment
relative to the start of the device is incorrect, because for some
filesystems main_blkaddr is not at a 2MB boundary relative to the start
of the device.

The entry will be used when validating reliable pinning file feature proposed
by "f2fs: support aligned pinned file".

Signed-off-by: Ramon Pantin <pantin@google.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: include charset encoding information in the superblock

Add charset encoding to f2fs to support casefolding. It is modeled after
the same feature introduced in commit c83ad55eaa91 ("ext4: include charset
encoding information in the superblock")

Currently this is not compatible with encryption, similar to the current
ext4 imlpementation. This will change in the future.

>From the ext4 patch:
"""
The s_encoding field stores a magic number indicating the encoding
format and version used globally by file and directory names in the
filesystem. The s_encoding_flags defines policies for using the charset
encoding, like how to handle invalid sequences. The magic number is
mapped to the exact charset table, but the mapping is specific to ext4.
Since we don't have any commitment to support old encodings, the only
encoding I am supporting right now is utf8-12.1.0.

The current implementation prevents the user from enabling encoding and
per-directory encryption on the same filesystem at the same time. The
incompatibility between these features lies in how we do efficient
directory searches when we cannot be sure the encryption of the user
provided fname will match the actual hash stored in the disk without
decrypting every directory entry, because of normalization cases. My
quickest solution is to simply block the concurrent use of these
features for now, and enable it later, once we have a better solution.
"""

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

f2fs: add fs-verity support

Add fs-verity support to f2fs. fs-verity is a filesystem feature that
enables transparent integrity protection and authentication of read-only
files. It uses a dm-verity like mechanism at the file level: a Merkle
tree is used to verify any block in the file in log(filesize) time. It
is implemented mainly by helper functions in fs/verity/. See
Documentation/filesystems/fsverity.rst for the full documentation.

The f2fs support for fs-verity consists of:

- Adding a filesystem feature flag and an inode flag for fs-verity.

- Implementing the fsverity_operations to support enabling verity on an
inode and reading/writing the verity metadata.

- Updating ->readpages() to verify data as it's read from verity files
and to support reading verity metadata pages.

- Updating ->write_begin(), ->write_end(), and ->writepages() to support
writing verity metadata pages.

- Calling the fs-verity hooks for ->open(), ->setattr(), and ->ioctl().

Like ext4, f2fs stores the verity metadata (Merkle tree and
fsverity_descriptor) past the end of the file, starting at the first 64K
boundary beyond i_size. This approach works because (a) verity files
are readonly, and (b) pages fully beyond i_size aren't visible to
userspace but can be read/written internally by f2fs with only some
relatively small changes to f2fs. Extended attributes cannot be used
because (a) f2fs limits the total size of an inode's xattr entries to
4096 bytes, which wouldn't be enough for even a single Merkle tree
block, and (b) f2fs encryption doesn't encrypt xattrs, yet the verity
metadata *must* be encrypted when the file is because it contains hashes
of the plaintext data.

Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

f2fs: avoid get_valid_blocks() for cleanup

No logic change.

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

f2fs: replace ktype default_attrs with default_groups

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace the default_attrs fields in f2fs_sb_ktype
and f2fs_feat_ktype with default_groups. Use the ATTRIBUTE_GROUPS macro
to create f2fs_groups and f2fs_feat_groups.

Fixes: fef4129ec2e6 ("f2fs: fix to be aware discard/preflush/dio command in is_idle()")
Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: replace ktype default_attrs with default_groups

The kobj_type default_attrs field is being replaced by the
default_groups field. Replace the default_attrs fields in f2fs_sb_ktype
and f2fs_feat_ktype with default_groups. Use the ATTRIBUTE_GROUPS macro
to create f2fs_groups and f2fs_feat_groups.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

f2fs: Add option to limit required GC for checkpoint=disable

This extends the checkpoint option to allow checkpoint=disable:%u[%]
This allows you to specify what how much of the disk you are willing
to lose access to while mounting with checkpoint=disable. If the amount
lost would be higher, the mount will return -EAGAIN. This can be given
as a percent of total space, or in blocks.

Currently, we need to run garbage collection until the amount of holes
is smaller than the OVP space. With the new option, f2fs can mark
space as unusable up front instead of requiring garbage collection until
the number of holes is small enough.

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

f2fs: run discard jobs when put_super

When we umount f2fs, we need to avoid long delay due to discard commands, which
is actually taking tens of seconds, if storage is very slow on UNMAP. So, this
patch introduces timeout-based work on it.

By default, let me give 5 seconds for discard.

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

fscrypt: remove filesystem specific build config option

In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

f2fs: UBSAN: set boolean value iostat_enable correctly

When setting /sys/fs/f2fs/<DEV>/iostat_enable with non-bool value, UBSAN
reports the following warning.

[ 7562.295484] ================================================================================
[ 7562.296531] UBSAN: Undefined behaviour in fs/f2fs/f2fs.h:2776:10
[ 7562.297651] load of value 64 is not a valid value for type '_Bool'
[ 7562.298642] CPU: 1 PID: 7487 Comm: dd Not tainted 4.20.0-rc4+ #79
[ 7562.298653] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 7562.298662] Call Trace:
[ 7562.298760] dump_stack+0x46/0x5b
[ 7562.298811] ubsan_epilogue+0x9/0x40
[ 7562.298830] __ubsan_handle_load_invalid_value+0x72/0x90
[ 7562.298863] f2fs_file_write_iter+0x29f/0x3f0
[ 7562.298905] __vfs_write+0x115/0x160
[ 7562.298922] vfs_write+0xa7/0x190
[ 7562.298934] ksys_write+0x50/0xc0
[ 7562.298973] do_syscall_64+0x4a/0xe0
[ 7562.298992] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 7562.299001] RIP: 0033:0x7fa45ec19c00
[ 7562.299004] Code: 73 01 c3 48 8b 0d 88 92 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d dd eb 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ce 8f 01 00 48 89 04 24
[ 7562.299044] RSP: 002b:00007ffca52b49e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 7562.299052] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa45ec19c00
[ 7562.299059] RDX: 0000000000000400 RSI: 000000000093f000 RDI: 0000000000000001
[ 7562.299065] RBP: 000000000093f000 R08: 0000000000000004 R09: 0000000000000000
[ 7562.299071] R10: 00007ffca52b47b0 R11: 0000000000000246 R12: 0000000000000400
[ 7562.299077] R13: 000000000093f000 R14: 000000000093f400 R15: 0000000000000000
[ 7562.299091] ================================================================================

So, if iostat_enable is enabled, set its value as true.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check inject_rate validity during configuring

Type of inject_rate is unsigned int, let's check new value's
validity during configuring.

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

f2fs: export migration_granularity sysfs entry

Add one sysfs entry to control migration granularity of GC in large
section f2fs, it can be tuned to mitigate heavy overhead of migrating
huge number of blocks in large section.

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

f2fs: clean up f2fs_sb_has_##feature_name

In F2FS_HAS_FEATURE(), we will use F2FS_SB(sb) to get sbi pointer to
access .raw_super field, to avoid unneeded pointer conversion, this
patch changes to F2FS_HAS_FEATURE() accept sbi parameter directly.

Just do cleanup, no logic change.

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

f2fs: support superblock checksum

Now we support crc32 checksum for superblock.

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

f2fs: add new idle interval timing for discard and gc paths

This helps to control the frequency of submission of discard and
GC requests independently, based on the need.

Suggested-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
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: fix performance issue observed with multi-thread sequential read

This reverts the commit - "b93f771 - f2fs: remove writepages lock"
to fix the drop in sequential read throughput.

Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L
device: UFS

Before -
read throughput: 185 MB/s
total read requests: 85177 (of these ~80000 are 4KB size requests).
total write requests: 2546 (of these ~2208 requests are written in 512KB).

After -
read throughput: 758 MB/s
total read requests: 2417 (of these ~2042 are 512KB reads).
total write requests: 2701 (of these ~2034 requests are written in 512KB).

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

f2fs: wake up gc thread immediately when gc_urgent is set

Fixes: 5b0e95398e2b ("f2fs: introduce sbi->gc_mode to determine the policy")
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add proc entry to show victim_secmap bitmap

This patch adds a new proc entry to show victim_secmap information in
more detail, which is very helpful to know the get_victim candidate
status clearly, and helpful to debug problems (e.g., some sections can
not gc all of its blocks, since some blocks belong to atomic file,
leaving victim_secmap with section bit setting, in extrem case, this
will lead all bytes of victim_secmap setting with 0xff).

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 defined but not used build warnings

Fix build warnings in f2fs when CONFIG_PROC_FS is not enabled
by marking the unused functions as __maybe_unused.

../fs/f2fs/sysfs.c:519:12: warning: 'segment_info_seq_show' defined but not used [-Wunused-function]
../fs/f2fs/sysfs.c:546:12: warning: 'segment_bits_seq_show' defined but not used [-Wunused-function]
../fs/f2fs/sysfs.c:570:12: warning: 'iostat_info_seq_show' defined but not used [-Wunused-function]

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

f2fs: avoid potential deadlock in f2fs_sbi_store

[ 155.018460] ======================================================
[ 155.021431] WARNING: possible circular locking dependency detected
[ 155.024339] 4.18.0-rc3+ #5 Tainted: G OE
[ 155.026879] ------------------------------------------------------
[ 155.029783] umount/2901 is trying to acquire lock:
[ 155.032187] 00000000c4282f1f (kn->count#130){++++}, at: kernfs_remove+0x1f/0x30
[ 155.035439]
[ 155.035439] but task is already holding lock:
[ 155.038892] 0000000056e4307b (&type->s_umount_key#41){++++}, at: deactivate_super+0x33/0x50
[ 155.042602]
[ 155.042602] which lock already depends on the new lock.
[ 155.042602]
[ 155.047465]
[ 155.047465] the existing dependency chain (in reverse order) is:
[ 155.051354]
[ 155.051354] -> #1 (&type->s_umount_key#41){++++}:
[ 155.054768] f2fs_sbi_store+0x61/0x460 [f2fs]
[ 155.057083] kernfs_fop_write+0x113/0x1a0
[ 155.059277] __vfs_write+0x36/0x180
[ 155.061250] vfs_write+0xbe/0x1b0
[ 155.063179] ksys_write+0x55/0xc0
[ 155.065068] do_syscall_64+0x60/0x1b0
[ 155.067071] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 155.069529]
[ 155.069529] -> #0 (kn->count#130){++++}:
[ 155.072421] __kernfs_remove+0x26f/0x2e0
[ 155.074452] kernfs_remove+0x1f/0x30
[ 155.076342] kobject_del.part.5+0xe/0x40
[ 155.078354] f2fs_put_super+0x12d/0x290 [f2fs]
[ 155.080500] generic_shutdown_super+0x6c/0x110
[ 155.082655] kill_block_super+0x21/0x50
[ 155.084634] kill_f2fs_super+0x9c/0xc0 [f2fs]
[ 155.086726] deactivate_locked_super+0x3f/0x70
[ 155.088826] cleanup_mnt+0x3b/0x70
[ 155.090584] task_work_run+0x93/0xc0
[ 155.092367] exit_to_usermode_loop+0xf0/0x100
[ 155.094466] do_syscall_64+0x162/0x1b0
[ 155.096312] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 155.098603]
[ 155.098603] other info that might help us debug this:
[ 155.098603]
[ 155.102418] Possible unsafe locking scenario:
[ 155.102418]
[ 155.105134] CPU0 CPU1
[ 155.107037] ---- ----
[ 155.108910] lock(&type->s_umount_key#41);
[ 155.110674] lock(kn->count#130);
[ 155.113010] lock(&type->s_umount_key#41);
[ 155.115608] lock(kn->count#130);

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

f2fs: clean up symbol namespace

As Ted reported:

"Hi, I was looking at f2fs's sources recently, and I noticed that there
is a very large number of non-static symbols which don't have a f2fs
prefix. There's well over a hundred (see attached below).

As one example, in fs/f2fs/dir.c there is:

unsigned char get_de_type(struct f2fs_dir_entry *de)

This function is clearly only useful for f2fs, but it has a generic
name. This means that if any other file system tries to have the same
symbol name, there will be a symbol conflict and the kernel would not
successfully build. It also means that when someone is looking f2fs
sources, it's not at all obvious whether a function such as
read_data_page(), invalidate_blocks(), is a generic kernel function
found in the fs, mm, or block layers, or a f2fs specific function.

You might want to fix this at some point. Hopefully Kent's bcachefs
isn't similarly using genericly named functions, since that might
cause conflicts with f2fs's functions --- but just as this would be a
problem that we would rightly insist that Kent fix, this is something
that we should have rightly insisted that f2fs should have fixed
before it was integrated into the mainline kernel.

acquire_orphan_inode
add_ino_entry
add_orphan_inode
allocate_data_block
allocate_new_segments
alloc_nid
alloc_nid_done
alloc_nid_failed
available_free_memory
...."

This patch adds "f2fs_" prefix for all non-static symbols in order to:
a) avoid conflict with other kernel generic symbols;
b) to indicate the function is f2fs specific one instead of generic
one;

Reported-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid race during access gc_thread pointer

Thread A Thread B
- f2fs_remount
- stop_gc_thread
- f2fs_sbi_store
sbi->gc_thread = NULL;
access sbi->gc_thread->gc_*

Previously, we allocate memory for sbi->gc_thread based on background
gc thread mount option, the memory can be released if we turn off
that mount option, but still there are several places access gc_thread
pointer without considering race condition, result in NULL point
dereference.

In order to fix this issue, use sb->s_umount to exclude those operations.

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

f2fs: introduce sbi->gc_mode to determine the policy

This is to avoid sbi->gc_thread pointer access.

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

f2fs: fix spelling mistake: "extenstion" -> "extension"

Trivial fix to spelling mistake in extension list text

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't split checkpoint in fstrim

Now, we issue discard asynchronously in separated thread instead of in
checkpoint, after that, we won't encounter long latency in checkpoint
due to huge number of synchronous discard command handling, so, we don't
need to split checkpoint to do trim in batch, merge it and obsolete
related sysfs entry.

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

proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>

f2fs: introduce F2FS_FEATURE_LOST_FOUND feature

This patch introduces a new feature, F2FS_FEATURE_LOST_FOUND, which
is set by mkfs. mkfs creates a directory named lost+found, which saves
unreachable files. If fsck finds a file which has no parent, or its
parent is removed by fsck, the file will be placed under lost+found
directory by fsck.

lost+found directory could not be encrypted. As a result, the root
directory cannot be encrypted too. So if LOST_FOUND feature is enabled,
let's avoid to encrypt root directory.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: wrap all options with f2fs_sb_info.mount_opt

This patch merges miscellaneous mount options into struct f2fs_mount_info,
After this patch, once we add new mount option, we don't need to worry
about recovery of it in remount_fs(), since we will recover the
f2fs_sb_info.mount_opt including all options.

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

f2fs: support hot file extension

This patch supports to recognize hot file extension in f2fs, so that we
can allocate proper hot segment location for its data, which can lead to
better hot/cold seperation in filesystem.

In addition, we changes a bit on query/add/del operation method for
extension_list sysfs entry as below:

- Query: cat /sys/fs/f2fs/<disk>/extension_list
- Add: echo 'extension' > /sys/fs/f2fs/<disk>/extension_list
- Del: echo '!extension' > /sys/fs/f2fs/<disk>/extension_list
- Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
- Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
- [h] means add/del hot file extension
- [c] means add/del cold file extension

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

f2fs: expose extension_list sysfs entry

This patch adds a sysfs entry 'extension_list' to support
query/add/del item in extension list.

Query:
cat /sys/fs/f2fs/<device>/extension_list

Add:
echo 'extension' > /sys/fs/f2fs/<device>/extension_list

Del:
echo '!extension' > /sys/fs/f2fs/<device>/extension_list

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

f2fs: clean up f2fs_sb_has_xxx functions

This patch introduces F2FS_FEATURE_FUNCS to clean up the definitions of
different f2fs_sb_has_xxx functions.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support inode creation time

This patch adds creation time field in inode layout to support showing
kstat.btime in ->statx.

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

f2fs: add an ioctl to disable GC for specific file

This patch gives a flag to disable GC on given file, which would be useful, when
user wants to keep its block map. It also conducts in-place-update for dontmove
file.

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

f2fs: add reserved blocks for root user

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.

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

f2fs: introduce sysfs readdir_ra to readahead inode block in readdir

This patch introduces a sysfs interface readdir_ra to enable/disable
readaheading inode block in f2fs_readdir. When readdir_ra is enabled,
it improves the performance of "readdir + stat".

For 300,000 files:
time find /data/test > /dev/null
disable readdir_ra: 1m25.69s real 0m01.94s user 0m50.80s system
enable readdir_ra: 0m18.55s real 0m00.44s user 0m15.39s system

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add quota_ino feature infra

This patch adds quota_ino feature infra to be used for quota files.

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

f2fs: export SSR allocation threshold

This patch exports min_ssr_segments threshold in sysfs to let user
control triggering SSR allocation flexibly.

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

f2fs: support soft block reservation

It supports to extend reserved_blocks sysfs interface to be soft
threshold, which allows user configure it exceeding current available
user space. This patch also introduces a new sysfs interface called
current_reserved_blocks, which shows the current blocks that have
already been reserved.

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

f2fs: support flexible inline xattr size

Now, in product, more and more features based on file encryption were
introduced, their demand of xattr space is increasing, however, inline
xattr has fixed-size of 200 bytes, once inline xattr space is full, new
increased xattr data would occupy additional xattr block which may bring
us more space usage and performance regression during persisting.

In order to resolve above issue, it's better to expand inline xattr size
flexibly according to user's requirement.

So this patch introduces new filesystem feature 'flexible inline xattr',
and new mount option 'inline_xattr_size=%u', once mkfs enables the
feature, we can use the option to make f2fs supporting flexible inline
xattr size.

To support this feature, we add extra attribute i_inline_xattr_size in
inode layout, indicating that how many space inline xattr borrows from
block address mapping space in inode layout, by this, we can easily
locate and store flexible-sized inline xattr data in inode.

Inode disk layout:
+----------------------+
| .i_mode |
| ... |
| .i_ext |
+----------------------+
| .i_extra_isize |
| .i_inline_xattr_size |-----------+
| ... | |
+----------------------+ |
| .i_addr | |
| - block address or | |
| - inline data | |
+----------------------+<---+ v
| inline xattr | +---inline xattr range
+----------------------+<---+
| .i_nid |
+----------------------+
| node_footer |
| (nid, ino, offset) |
+----------------------+

Note that, we have to cnosider backward compatibility which reserved
inline_data space, 200 bytes, all the time, reported by Sheng Yong.

Previous inline data or directory always reserved 200 bytes in inode layout,
even if inline_xattr is disabled. In order to keep inline_dentry's structure
for backward compatibility, we get the space back only from inline_data.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reported-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: show # of dirty segments via sysfs

This patch adds one sysfs entry to show # of dirty segments which can be
used for gc timing by user.

Reviewed-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: fix to show correct discard_granularity in sysfs

Fix below incorrect display when reading discard_granularity sysfs node.

$ cat /sys/fs/f2fs/<device>/discard_granularity
$ 16
$ echo 32 > /sys/fs/f2fs/<device>/discard_granularity
$ cat /sys/fs/f2fs/<device>/discard_granularity
$ 16

Signed-off-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: issue discard commands if gc_urgent is set

It's time to issue all the discard commands, if user sets the idle time.

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

f2fs: introduce discard_granularity sysfs entry

Commit d618ebaf0aa8 ("f2fs: enable small discard by default") enables
f2fs to issue 4K size discard in real-time discard mode. However, issuing
smaller discard may cost more lifetime but releasing less free space in
flash device. Since f2fs has ability of separating hot/cold data and
garbage collection, we can expect that small-sized invalid region would
expand soon with OPU, deletion or garbage collection on valid datas, so
it's better to delay or skip issuing smaller size discards, it could help
to reduce overmuch consumption of IO bandwidth and lifetime of flash
storage.

This patch makes f2fs selectng 64K size as its default minimal
granularity, and issue discard with the size which is not smaller than
minimal granularity. Also it exposes discard granularity as sysfs entry
for configuration in different scenario.

Jaegeuk Kim:
We must issue all the accumulated discard commands when fstrim is called.
So, I've added pend_list_tag[] to indicate whether we should issue the
commands or not. If tag sets P_ACTIVE or P_TRIM, we have to issue them.
P_TRIM is set once at a time, given fstrim trigger.
In addition, issue_discard_thread is calling too much due to the number of
discard commands remaining in the pending list. I added a timer to control
it likewise gc_thread.

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

f2fs: introduce gc_urgent mode for background GC

This patch adds a sysfs entry to control urgent mode for background GC.
If this is set, background GC thread conducts GC with gc_urgent_sleep_time
all the time.

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

f2fs: add app/fs io stat

This patch enables inner app/fs io stats and introduces below virtual fs
nodes for exposing stats info:
/sys/fs/f2fs/<dev>/iostat_enable
/proc/fs/f2fs/<dev>/iostat_info

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: fix wrong stat assignment]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: expose features to sysfs entry

This patch exposes what features are supported by current f2fs build to sysfs
entry via:

/sys/fs/f2fs/features/
/sys/fs/f2fs/dev/features

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

f2fs: avoid naming confusion of sysfs init

This patch changes the function names of sysfs init to follow ext4.

f2fs_init_sysfs <-> f2fs_register_sysfs
f2fs_exit_sysfs <-> f2fs_unregister_sysfs

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

f2fs: include seq_file.h for sysfs.c

This patch includes seq_file.h to avoid compile error.

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

f2fs: introduce reserved_blocks in sysfs

In this patch, we add a new sysfs interface, with it, we can control
number of reserved blocks in system which could not be used by user,
it enable f2fs to let user to configure for adjusting over-provision
ratio dynamically instead of changing it by mkfs.

So we can expect it will help to reserve more free space for relieving
GC in both filesystem and flash device.

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

f2fs: move sysfs code from super.c to fs/f2fs/sysfs.c

Codes related to sysfs and procfs are dispersive and mixed with sb
related codes, but actually these codes are independent from others,
so split them from super.c, and reorgnize and manger them in sysfs.c.

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