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>
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>
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>
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>
In this cycle, we've addressed some performance issues such as lock contention,
misbehaving compress_cache, allowing extent_cache for compressed files, and new
sysfs to adjust ra_size for fadvise. In order to diagnose the performance issues
quickly, we also added an iostat which shows the IO latencies periodically. On
the stability side, we've found two memory leakage cases in the error path in
compression flow. And, we've also fixed various corner cases in fiemap, quota,
checkpoint=disable, zstd, and so on.
Enhancement:
- avoid long checkpoint latency by releasing nat_tree_lock
- collect and show iostats periodically
- support extent_cache for compressed files
- add a sysfs entry to manage ra_size given fadvise(POSIX_FADV_SEQUENTIAL)
- report f2fs GC status via sysfs
- add discard_unit=%s in mount option to handle zoned device
Bug fix:
- fix two memory leakages when an error happens in the compressed IO flow
- fix commpress_cache to get the right LBA
- fix fiemap to deal with compressed case correctly
- fix wrong EIO returns due to SBI_NEED_FSCK
- fix missing writes when enabling checkpoint back
- fix quota deadlock
- fix zstd level mount option
In addition to the above major updates, we've cleaned up several code paths such
as dio, unnecessary operations, debugfs/f2fs/status, sanity check, and typos.
-----BEGIN PGP SIGNATURE-----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=W67o
-----END PGP SIGNATURE-----
Merge tag 'f2fs-for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this cycle, we've addressed some performance issues such as lock
contention, misbehaving compress_cache, allowing extent_cache for
compressed files, and new sysfs to adjust ra_size for fadvise.
In order to diagnose the performance issues quickly, we also added an
iostat which shows the IO latencies periodically.
On the stability side, we've found two memory leakage cases in the
error path in compression flow. And, we've also fixed various corner
cases in fiemap, quota, checkpoint=disable, zstd, and so on.
Enhancements:
- avoid long checkpoint latency by releasing nat_tree_lock
- collect and show iostats periodically
- support extent_cache for compressed files
- add a sysfs entry to manage ra_size given fadvise(POSIX_FADV_SEQUENTIAL)
- report f2fs GC status via sysfs
- add discard_unit=%s in mount option to handle zoned device
Bug fixes:
- fix two memory leakages when an error happens in the compressed IO flow
- fix commpress_cache to get the right LBA
- fix fiemap to deal with compressed case correctly
- fix wrong EIO returns due to SBI_NEED_FSCK
- fix missing writes when enabling checkpoint back
- fix quota deadlock
- fix zstd level mount option
In addition to the above major updates, we've cleaned up several code
paths such as dio, unnecessary operations, debugfs/f2fs/status, sanity
check, and typos"
* tag 'f2fs-for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (46 commits)
f2fs: should put a page beyond EOF when preparing a write
f2fs: deallocate compressed pages when error happens
f2fs: enable realtime discard iff device supports discard
f2fs: guarantee to write dirty data when enabling checkpoint back
f2fs: fix to unmap pages from userspace process in punch_hole()
f2fs: fix unexpected ENOENT comes from f2fs_map_blocks()
f2fs: fix to account missing .skipped_gc_rwsem
f2fs: adjust unlock order for cleanup
f2fs: Don't create discard thread when device doesn't support realtime discard
f2fs: rebuild nat_bits during umount
f2fs: introduce periodic iostat io latency traces
f2fs: separate out iostat feature
f2fs: compress: do sanity check on cluster
f2fs: fix description about main_blkaddr node
f2fs: convert S_IRUGO to 0444
f2fs: fix to keep compatibility of fault injection interface
f2fs: support fault injection for f2fs_kmem_cache_alloc()
f2fs: compress: allow write compress released file after truncate to zero
f2fs: correct comment in segment.h
f2fs: improve sbi status info in debugfs/f2fs/status
...
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>
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>
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>
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>
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>
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>
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>
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>
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 7ad08a58bf ("f2fs: Handle casefolding with Encryption")
Fixes: 7ad08a58bf ("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>
The casefolding feature is only supported when CONFIG_UNICODE is set.
This modifies the feature list f2fs presents under sysfs accordingly.
Fixes: 5aba54302a ("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>
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>
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>
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>
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>
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>
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>
In this round, we've made more work into per-file compression support. For
example, F2FS_IOC_GET|SET_COMPRESS_OPTION provides a way to change the
algorithm or cluster size per file. F2FS_IOC_COMPRESS|DECOMPRESS_FILE provides
a way to compress and decompress the existing normal files manually along with
a new mount option, compress_mode=fs|user, which can control who compresses the
data. Chao also added a checksum feature with a mount option so that we are able
to detect any corrupted cluster. In addition, Daniel contributed casefolding
with encryption patch, which will be used for Android devices.
Enhancement:
- add ioctls and mount option to manage per-file compression feature
- support casefolding with encryption
- support checksum for compressed cluster
- avoid IO starvation by replacing mutex with rwsem
- add sysfs, max_io_bytes, to control max bio size
Bug fix:
- fix use-after-free issue when compression and fsverity are enabled
- fix consistency corruption during fault injection test
- fix data offset for lseek
- get rid of buffer_head which has 32bits limit in fiemap
- fix some bugs in multi-partitions support
- fix nat entry count calculation in shrinker
- fix some stat information
And, we've refactored some logics and fix minor bugs as well.
-----BEGIN PGP SIGNATURE-----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=KneU
-----END PGP SIGNATURE-----
Merge tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've made more work into per-file compression support.
For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to
change the algorithm or cluster size per file. F2FS_IOC_COMPRESS |
DECOMPRESS_FILE provides a way to compress and decompress the existing
normal files manually.
There is also a new mount option, compress_mode=fs|user, which can
control who compresses the data.
Chao also added a checksum feature with a mount option so that
we are able to detect any corrupted cluster.
In addition, Daniel contributed casefolding with encryption patch,
which will be used for Android devices.
Summary:
Enhancements:
- add ioctls and mount option to manage per-file compression feature
- support casefolding with encryption
- support checksum for compressed cluster
- avoid IO starvation by replacing mutex with rwsem
- add sysfs, max_io_bytes, to control max bio size
Bug fixes:
- fix use-after-free issue when compression and fsverity are enabled
- fix consistency corruption during fault injection test
- fix data offset for lseek
- get rid of buffer_head which has 32bits limit in fiemap
- fix some bugs in multi-partitions support
- fix nat entry count calculation in shrinker
- fix some stat information
And, we've refactored some logics and fix minor bugs as well"
* tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits)
f2fs: compress: fix compression chksum
f2fs: fix shift-out-of-bounds in sanity_check_raw_super()
f2fs: fix race of pending_pages in decompression
f2fs: fix to account inline xattr correctly during recovery
f2fs: inline: fix wrong inline inode stat
f2fs: inline: correct comment in f2fs_recover_inline_data
f2fs: don't check PAGE_SIZE again in sanity_check_raw_super()
f2fs: convert to F2FS_*_INO macro
f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size
f2fs: don't allow any writes on readonly mount
f2fs: avoid race condition for shrinker count
f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
f2fs: add compress_mode mount option
f2fs: Remove unnecessary unlikely()
f2fs: init dirty_secmap incorrectly
f2fs: remove buffer_head which has 32bits limit
f2fs: fix wrong block count instead of bytes
f2fs: use new conversion functions between blks and bytes
f2fs: rename logical_to_blk and blk_to_logical
f2fs: fix kbytes written stat for multi-device case
...
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>
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>
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>
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: bf9e697ecd ("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>
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>
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>
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>
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>
In this round, we've added some knobs to enhance compression feature and harden
testing environment. In addition, we've fixed several bugs reported from Android
devices such as long discarding latency, device hanging during quota_sync, etc.
Enhancement:
- support lzo-rle algorithm
- add two ioctls to release and reserve blocks for compression
- support partial truncation/fiemap on compressed file
- introduce sysfs entries to attach IO flags explicitly
- add iostat trace point along with read io stat
Bug fix:
- fix long discard latency
- flush quota data by f2fs_quota_sync correctly
- fix to recover parent inode number for power-cut recovery
- fix lz4/zstd output buffer budget
- parse checkpoint mount option correctly
- avoid inifinite loop to wait for flushing node/meta pages
- manage discard space correctly
And some refactoring and clean up patches were added.
-----BEGIN PGP SIGNATURE-----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=MiEC
-----END PGP SIGNATURE-----
Merge tag 'f2fs-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've added some knobs to enhance compression feature
and harden testing environment. In addition, we've fixed several bugs
reported from Android devices such as long discarding latency, device
hanging during quota_sync, etc.
Enhancements:
- support lzo-rle algorithm
- add two ioctls to release and reserve blocks for compression
- support partial truncation/fiemap on compressed file
- introduce sysfs entries to attach IO flags explicitly
- add iostat trace point along with read io stat
Bug fixes:
- fix long discard latency
- flush quota data by f2fs_quota_sync correctly
- fix to recover parent inode number for power-cut recovery
- fix lz4/zstd output buffer budget
- parse checkpoint mount option correctly
- avoid inifinite loop to wait for flushing node/meta pages
- manage discard space correctly
And some refactoring and clean up patches were added"
* tag 'f2fs-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
f2fs: attach IO flags to the missing cases
f2fs: add node_io_flag for bio flags likewise data_io_flag
f2fs: remove unused parameter of f2fs_put_rpages_mapping()
f2fs: handle readonly filesystem in f2fs_ioc_shutdown()
f2fs: avoid utf8_strncasecmp() with unstable name
f2fs: don't return vmalloc() memory from f2fs_kmalloc()
f2fs: fix retry logic in f2fs_write_cache_pages()
f2fs: fix wrong discard space
f2fs: compress: don't compress any datas after cp stop
f2fs: remove unneeded return value of __insert_discard_tree()
f2fs: fix wrong value of tracepoint parameter
f2fs: protect new segment allocation in expand_inode_data
f2fs: code cleanup by removing ifdef macro surrounding
f2fs: avoid inifinite loop to wait for flushing node pages at cp_error
f2fs: flush dirty meta pages when flushing them
f2fs: fix checkpoint=disable:%u%%
f2fs: compress: fix zstd data corruption
f2fs: add compressed/gc data read IO stat
f2fs: fix potential use-after-free issue
f2fs: compress: don't handle non-compressed data in workqueue
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
In this round, we introduced casefolding support in f2fs, and fixed various bugs
in individual features such as IO alignment, checkpoint=disable, quota, and
swapfile.
Enhancement:
- support casefolding w/ enhancement in ext4
- support fiemap for directory
- support FS_IO_GET|SET_FSLABEL
Bug fix:
- fix IO stuck during checkpoint=disable
- avoid infinite GC loop
- fix panic/overflow related to IO alignment feature
- fix livelock in swap file
- fix discard command leak
- disallow dio for atomic_write
-----BEGIN PGP SIGNATURE-----
iQIzBAABCAAdFiEE00UqedjCtOrGVvQiQBSofoJIUNIFAl2FL1wACgkQQBSofoJI
UNIRdg/+M6QNiAazIbqzPXyUUkyZQYR5YKhu2abd49o/g38xjTq1afH0PZpQyDrA
9RncR4xsW8F241vPLVoCSanfaa+MxN6xHi3TrD8zYtZWxOcPF6v1ETHeUXGTHuJ2
gqlk+mm+CnY02M6rxW7XwixuXwttT3bF9+cf1YBWRpNoVrR+SjNqgeJS7FmJwXKd
nGKb+94OxuygL1NUop+LDUo3qRQjc0Sxv/7qj/K4lhqgTjhAxMYT2KvUP/1MZ7U0
Kh9WIayDXnpoioxMPnt4VEb+JgXfLLFELvQzNjwulk15GIweuJzwVYCBXcRoX0cK
eRBRmRy/kRp/e0R1gvl3kYrXQC2AC5QTlBVH/0ESwnaukFiUBKB509vH4aqE/vpB
Krldjfg+uMHkc7XiNBf1boDp713vJ76iRKUDWoVb6H/sPbdJ+jtrnUNeBP8CVpWh
u31SY1MppnmKhhsoCHQRbhbXO/Z29imBQgF9Tm3IFWImyLY3IU40vFj2fR15gJkL
X3x/HWxQynSqyqEOwAZrvhCRTvBAIGIVy5292Di1RkqIoh8saxcqiaywgLz1+eVE
0DCOoh8R6sSbfN/EEh+yZqTxmjo0VGVTw30XVI6QEo4cY5Vfc9u6dN6SRWVRvbjb
kPb3dKcMrttgbn3fcXU8Jbw1AOor9N6afHaqs0swQJyci2RwJyc=
=oonf
-----END PGP SIGNATURE-----
Merge tag 'f2fs-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we introduced casefolding support in f2fs, and fixed
various bugs in individual features such as IO alignment,
checkpoint=disable, quota, and swapfile.
Enhancement:
- support casefolding w/ enhancement in ext4
- support fiemap for directory
- support FS_IO_GET|SET_FSLABEL
Bug fix:
- fix IO stuck during checkpoint=disable
- avoid infinite GC loop
- fix panic/overflow related to IO alignment feature
- fix livelock in swap file
- fix discard command leak
- disallow dio for atomic_write"
* tag 'f2fs-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
f2fs: add a condition to detect overflow in f2fs_ioc_gc_range()
f2fs: fix to add missing F2FS_IO_ALIGNED() condition
f2fs: fix to fallback to buffered IO in IO aligned mode
f2fs: fix to handle error path correctly in f2fs_map_blocks
f2fs: fix extent corrupotion during directIO in LFS mode
f2fs: check all the data segments against all node ones
f2fs: Add a small clarification to CONFIG_FS_F2FS_FS_SECURITY
f2fs: fix inode rwsem regression
f2fs: fix to avoid accessing uninitialized field of inode page in is_alive()
f2fs: avoid infinite GC loop due to stale atomic files
f2fs: Fix indefinite loop in f2fs_gc()
f2fs: convert inline_data in prior to i_size_write
f2fs: fix error path of f2fs_convert_inline_page()
f2fs: add missing documents of reserve_root/resuid/resgid
f2fs: fix flushing node pages when checkpoint is disabled
f2fs: enhance f2fs_is_checkpoint_ready()'s readability
f2fs: clean up __bio_alloc()'s parameter
f2fs: fix wrong error injection path in inc_valid_block_count()
f2fs: fix to writeout dirty inode during node flush
f2fs: optimize case-insensitive lookups
...
