862 Commits
Author SHA1 Message Date
Daeho JeongandJaegeuk Kim 02d91398a6 f2fs: fix to freeze GC and discard threads quickly
Suspend can fail if kernel threads do not freeze for a while.
f2fs_gc and f2fs_discard threads can perform long-running operations
that prevent them from reaching a freeze point in a timely manner.

This patch adds explicit freezing checks in the following locations:
1. f2fs_gc: Added a check at the 'retry' label to exit the loop quickly
   if freezing is requested, especially during heavy GC rounds.
2. __issue_discard_cmd: Added a 'suspended' flag to break both inner and
   outer loops during discard command issuance if freezing is detected
   after at least one command has been issued.
3. __issue_discard_cmd_orderly: Added a similar check for orderly discard
   to ensure responsiveness.

These checks ensure that the threads release locks safely and enter the
frozen state.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-04-02 16:24:20 +00:00
Chao YuandJaegeuk Kim 6af249c996 f2fs: fix to do sanity check on dcc->discard_cmd_cnt conditionally
Syzbot reported a f2fs bug as below:

------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:1900!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 6527 Comm: syz.5.110 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:f2fs_issue_discard_timeout+0x59b/0x5a0 fs/f2fs/segment.c:1900
Code: d9 80 e1 07 80 c1 03 38 c1 0f 8c d6 fe ff ff 48 89 df e8 a8 5e fa fd e9 c9 fe ff ff e8 4e 46 94 fd 90 0f 0b e8 46 46 94 fd 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc9000494f940 EFLAGS: 00010283
RAX: ffffffff843009ca RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc9001ca78000 RSI: 00000000000029f3 RDI: 00000000000029f4
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100893a431 R12: 1ffff1100893a430
R13: 1ffff1100c2b702c R14: dffffc0000000000 R15: ffff8880449d2160
FS:  00007ffa35fed6c0(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b68634000 CR3: 0000000039f62000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __f2fs_remount fs/f2fs/super.c:2960 [inline]
 f2fs_reconfigure+0x108a/0x1710 fs/f2fs/super.c:5443
 reconfigure_super+0x227/0x8a0 fs/super.c:1080
 do_remount fs/namespace.c:3391 [inline]
 path_mount+0xdc5/0x10e0 fs/namespace.c:4151
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa37dbda0a

The root cause is there will be race condition in between f2fs_ioc_fitrim()
and f2fs_remount():

- f2fs_remount			- f2fs_ioc_fitrim
 - f2fs_issue_discard_timeout
  - __issue_discard_cmd
  - __drop_discard_cmd
  - __wait_all_discard_cmd
				 - f2fs_trim_fs
				  - f2fs_write_checkpoint
				   - f2fs_clear_prefree_segments
				    - f2fs_issue_discard
				     - __issue_discard_async
				      - __queue_discard_cmd
				       - __update_discard_tree_range
				        - __insert_discard_cmd
				         - __create_discard_cmd
				         : atomic_inc(&dcc->discard_cmd_cnt);
  - sanity check on dcc->discard_cmd_cnt (expect discard_cmd_cnt to be zero)

This will only happen when fitrim races w/ remount rw, if we remount to
readonly filesystem, remount will wait until mnt_pcp.mnt_writers to zero,
that means fitrim is not in process at that time.

Cc: stable@kernel.org
Fixes: 2482c4325d ("f2fs: detect bug_on in f2fs_wait_discard_bios")
Reported-by: syzbot+62538b67389ee582837a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/69b07d7c.050a0220.8df7.09a1.GAE@google.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-04-02 16:24:19 +00:00
Yongpeng YangandJaegeuk Kim 1eaf7ee2e6 f2fs: drop unused sbi parameter from f2fs_in_warm_node_list()
The sbi parameter in f2fs_in_warm_node_list() is not used. Remove it to
simplify the function.

Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-03-24 17:21:00 +00:00
Daeho JeongandJaegeuk Kim 91b76f1059 f2fs: fix incomplete block usage in compact SSA summaries
In a previous commit, a bug was introduced where compact SSA summaries
failed to utilize the entire block space in non-4KB block size
configurations, leading to inefficient space management.

This patch fixes the calculation logic to ensure that compact SSA
summaries can fully occupy the block regardless of the block size.

Reported-by: Chris Mason <clm@meta.com>
Fixes: e48e16f3e3 ("f2fs: support non-4KB block size without packed_ssa feature")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-30 17:03:49 +00:00
Daeho JeongandJaegeuk Kim e48e16f3e3 f2fs: support non-4KB block size without packed_ssa feature
Currently, F2FS requires the packed_ssa feature to be enabled when
utilizing non-4KB block sizes (e.g., 16KB). This restriction limits
the flexibility of filesystem formatting options.

This patch allows F2FS to support non-4KB block sizes even when the
packed_ssa feature is disabled. It adjusts the SSA calculation logic to
correctly handle summary entries in larger blocks without the packed
layout.

Cc: stable@kernel.org
Fixes: 7ee8bc3942 ("f2fs: revert summary entry count from 2048 to 512 in 16kb block support")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-17 00:00:34 +00:00
Chao YuandJaegeuk Kim 1dd3b437d4 f2fs: make FAULT_DISCARD obsolete
__blkdev_issue_discard() in __submit_discard_cmd() will never fail, so
let's make FAULT_DISCARD fault injection obsolete.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-17 00:00:34 +00:00
Chao YuandJaegeuk Kim d36de29f4b f2fs: sysfs: introduce inject_lock_timeout
This patch adds a new sysfs node in /sys/fs/f2fs/<disk>/inject_lock_timeout,
it relies on CONFIG_F2FS_FAULT_INJECTION kernel config.

It can be used to simulate different type of timeout in lock duration.

==========     ===============================
Flag_Value     Flag_Description
==========     ===============================
0x00000000     No timeout (default)
0x00000001     Simulate running time
0x00000002     Simulate IO type sleep time
0x00000003     Simulate Non-IO type sleep time
0x00000004     Simulate runnable time
==========     ===============================

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-07 03:17:08 +00:00
Chao YuandJaegeuk Kim 7a127c80b0 f2fs: rename FAULT_TIMEOUT to FAULT_ATOMIC_TIMEOUT
No logic changes.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-07 03:17:08 +00:00
Chao YuandJaegeuk Kim e605302c14 f2fs: trace elapsed time for gc_lock lock
Use f2fs_{down,up}_write_trace for gc_lock to trace lock elapsed time.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-07 03:17:07 +00:00
Chao YuandJaegeuk Kim 66e9e0d55d f2fs: trace elapsed time for cp_rwsem lock
Use f2fs_{down,up}_read_trace for cp_rwsem to trace lock elapsed time.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-07 03:17:06 +00:00
Yongpeng YangandJaegeuk Kim db1a8a7813 f2fs: return immediately after submitting the specified folio in __submit_merged_write_cond
f2fs_folio_wait_writeback ensures the folio write is submitted to the
block layer via __submit_merged_write_cond, then waits for the folio to
complete. Other I/O submissions are irrelevant to
f2fs_folio_wait_writeback. Thus, if the folio write bio is already
submitted, the function can return immediately. This patch adds a
writeback parameter to __submit_merged_write_cond(), which signals an
immediate return after submitting the target folio, and waitting
writeback can use this parameter.

Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2026-01-01 03:29:40 +00:00
Chaitanya KulkarniandJaegeuk Kim 76ee7fd6af f2fs: ignore discard return value
__blkdev_issue_discard() always returns 0, making the error assignment
in __submit_discard_cmd() dead code.

Initialize err to 0 and remove the error assignment from the
__blkdev_issue_discard() call to err. Move fault injection code into
already present if branch where err is set to -EIO.

This preserves the fault injection behavior while removing dead error
handling.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:06 +00:00
Chao YuandJaegeuk Kim d31e0de8b8 f2fs: change default schedule timeout value
This patch changes default schedule timeout value from 20ms to 1ms,
in order to give caller more chances to check whether IO or non-IO
congestion condition has already been mitigable.

In addition, default interval of periodical discard submission is
kept to 20ms.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:05 +00:00
Chao YuandJaegeuk Kim 76e780d88c f2fs: introduce f2fs_schedule_timeout()
In f2fs retry logic, we will call f2fs_io_schedule_timeout() to sleep as
uninterruptible state (waiting for IO) for a while, however, in several
paths below, we are not blocked by IO:
- f2fs_write_single_data_page() return -EAGAIN due to racing on cp_rwsem.
- f2fs_flush_device_cache() failed to submit preflush command.
- __issue_discard_cmd_range() sleeps periodically in between two in batch
discard submissions.

So, in order to reveal state of task more accurate, let's introduce
f2fs_schedule_timeout() and call it in above paths in where we are waiting
for non-IO reasons.

Then we can get real reason of uninterruptible sleep for a thread in
tracepoint, perfetto, etc.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:05 +00:00
Chao YuandJaegeuk Kim 30a8496694 f2fs: use memalloc_retry_wait() as much as possible
memalloc_retry_wait() is recommended in memory allocation retry logic,
use it as much as possible.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:05 +00:00
Daeho JeongandJaegeuk Kim 7ee8bc3942 f2fs: revert summary entry count from 2048 to 512 in 16kb block support
The recent increase in the number of Segment Summary Area (SSA) entries
from 512 to 2048 was an unintentional change in logic of 16kb block
support. This commit corrects the issue.

To better utilize the space available from the erroneous 2048-entry
calculation, we are implementing a solution to share the currently
unused SSA space with neighboring segments. This enhances overall
SSA utilization without impacting the established 8MB segment size.

Fixes: d7e9a9037d ("f2fs: Support Block Size == Page Size")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:04 +00:00
Xiaole HeandJaegeuk Kim 27bf6a637b f2fs: fix age extent cache insertion skip on counter overflow
The age extent cache uses last_blocks (derived from
allocated_data_blocks) to determine data age. However, there's a
conflict between the deletion
marker (last_blocks=0) and legitimate last_blocks=0 cases when
allocated_data_blocks overflows to 0 after reaching ULLONG_MAX.

In this case, valid extents are incorrectly skipped due to the
"if (!tei->last_blocks)" check in __update_extent_tree_range().

This patch fixes the issue by:
1. Reserving ULLONG_MAX as an invalid/deletion marker
2. Limiting allocated_data_blocks to range [0, ULLONG_MAX-1]
3. Using F2FS_EXTENT_AGE_INVALID for deletion scenarios
4. Adjusting overflow age calculation from ULLONG_MAX to (ULLONG_MAX-1)

Reproducer (using a patched kernel with allocated_data_blocks
initialized to ULLONG_MAX - 3 for quick testing):

Step 1: Mount and check initial state
  # dd if=/dev/zero of=/tmp/test.img bs=1M count=100
  # mkfs.f2fs -f /tmp/test.img
  # mkdir -p /mnt/f2fs_test
  # mount -t f2fs -o loop,age_extent_cache /tmp/test.img /mnt/f2fs_test
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 18446744073709551612 # ULLONG_MAX - 3
  Inner Struct Count: tree: 1(0), node: 0

Step 2: Create files and write data to trigger overflow
  # touch /mnt/f2fs_test/{1,2,3,4}.txt; sync
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 18446744073709551613 # ULLONG_MAX - 2
  Inner Struct Count: tree: 5(0), node: 1

  # dd if=/dev/urandom of=/mnt/f2fs_test/1.txt bs=4K count=1; sync
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 18446744073709551614 # ULLONG_MAX - 1
  Inner Struct Count: tree: 5(0), node: 2

  # dd if=/dev/urandom of=/mnt/f2fs_test/2.txt bs=4K count=1; sync
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 18446744073709551615 # ULLONG_MAX
  Inner Struct Count: tree: 5(0), node: 3

  # dd if=/dev/urandom of=/mnt/f2fs_test/3.txt bs=4K count=1; sync
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 0 # Counter overflowed!
  Inner Struct Count: tree: 5(0), node: 4

Step 3: Trigger the bug - next write should create node but gets skipped
  # dd if=/dev/urandom of=/mnt/f2fs_test/4.txt bs=4K count=1; sync
  # cat /sys/kernel/debug/f2fs/status | grep -A 4 "Block Age"
  Allocated Data Blocks: 1
  Inner Struct Count: tree: 5(0), node: 4

  Expected: node: 5 (new extent node for 4.txt)
  Actual: node: 4 (extent insertion was incorrectly skipped due to
  last_blocks = allocated_data_blocks = 0 in __get_new_block_age)

After this fix, the extent node is correctly inserted and node count
becomes 5 as expected.

Fixes: 71644dff48 ("f2fs: add block_age-based extent cache")
Cc: stable@kernel.org
Signed-off-by: Xiaole He <hexiaole1994@126.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-12-04 02:00:03 +00:00
Jaegeuk Kim c872b6279c f2fs: allocate HOT_DATA for IPU writes
Let's split IPU writes in hot data area to improve the GC efficiency.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-09-02 20:16:04 +00:00
Liao YuanhongandJaegeuk Kim b639c20e74 f2fs: Use allocate_section_policy to control write priority in multi-devices setups
Introduces two new sys nodes: allocate_section_hint and
allocate_section_policy. The allocate_section_hint identifies the boundary
between devices, measured in sections; it defaults to the end of the device
for single storage setups, and the end of the first device for multiple
storage setups. The allocate_section_policy determines the write strategy,
with a default value of 0 for normal sequential write strategy. A value of
1 prioritizes writes before the allocate_section_hint, while a value of 2
prioritizes writes after it.

This strategy addresses the issue where, despite F2FS supporting multiple
devices, SOC vendors lack multi-devices support (currently only supporting
zoned devices). As a workaround, multiple storage devices are mapped to a
single dm device. Both this workaround and the F2FS multi-devices solution
may require prioritizing writing to certain devices, such as a device with
better performance or when switching is needed due to performance
degradation near a device's end. For scenarios with more than two devices,
sort them at mount time to utilize this feature.

When using this feature with a single storage device, it has almost no
impact. However, for configurations where multiple storage devices are
mapped to the same dm device using F2FS, utilizing this feature can provide
some optimization benefits. Therefore, I believe it should not be limited
to just multi-devices usage.

Signed-off-by: Liao Yuanhong <liaoyuanhong@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-08-29 20:48:47 +00:00
mason.zhangandJaegeuk Kim 76bb6a72bc f2fs: add error checking in do_write_page()
Otherwise, the filesystem may unaware of potential file corruption.

Signed-off-by: mason.zhang <masonzhang.linuxer@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-08-11 17:03:27 +00:00
Matthew Wilcox (Oracle)andJaegeuk Kim 06e42bf432 f2fs: Pass a folio to f2fs_submit_merged_write_cond()
Most callers pass NULL, and the one that passes a page already has a
folio.  Also convert __submit_merged_write_cond() to take a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-07-22 15:58:05 +00:00
Matthew Wilcox (Oracle)andJaegeuk Kim ad38574a8e f2fs: Pass a folio to ADDRS_PER_PAGE()
All callers now have a folio so pass it in.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-07-22 15:56:59 +00:00
Matthew Wilcox (Oracle)andJaegeuk Kim fb92a5c9f8 f2fs: Pass a folio to IS_DNODE()
All callers now have a folio so pass it in.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-07-22 15:56:50 +00:00
Matthew Wilcox (Oracle)andJaegeuk Kim 1fd0dffdb4 f2fs: Pass a folio to is_cold_node()
All callers now have a folio so pass it in.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-07-22 15:56:45 +00:00
Matthew Wilcox (Oracle)andJaegeuk Kim d342b7adad f2fs: Add fio->folio
Put fio->page insto a union with fio->folio.  This lets us remove a
lot of folio->page and page->folio conversions.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2025-07-22 15:56:39 +00:00