<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/f2fs, branch v6.12</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>f2fs: allow parallel DIO reads</title>
<updated>2024-10-11T15:12:07+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk@kernel.org</email>
</author>
<published>2024-10-09T19:40:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=332fade75d0ecd88cd19556fce0f9cc8322de434'/>
<id>332fade75d0ecd88cd19556fce0f9cc8322de434</id>
<content type='text'>
This fixes a regression which prevents parallel DIO reads.

Fixes: 0cac51185e65 ("f2fs: fix to avoid racing in between read and OPU dio write")
Reviewed-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This fixes a regression which prevents parallel DIO reads.

Fixes: 0cac51185e65 ("f2fs: fix to avoid racing in between read and OPU dio write")
Reviewed-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>move asm/unaligned.h to linux/unaligned.h</title>
<updated>2024-10-02T21:23:23+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2024-10-01T19:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f60d5f6bbc12e782fac78110b0ee62698f3b576'/>
<id>5f60d5f6bbc12e782fac78110b0ee62698f3b576</id>
<content type='text'>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'f2fs-for-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs</title>
<updated>2024-09-24T22:12:38+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-24T22:12:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=79952bdcbcea53e57c2ca97e7448f8a6bdb6106a'/>
<id>79952bdcbcea53e57c2ca97e7448f8a6bdb6106a</id>
<content type='text'>
Pull f2fs updates from Jaegeuk Kim:
 "The main changes include converting major IO paths to use folio, and
  adding various knobs to control GC more flexibly for Zoned devices.

  In addition, there are several patches to address corner cases of
  atomic file operations and better support for file pinning on zoned
  device.

  Enhancement:
   - add knobs to tune foreground/background GCs for Zoned devices
   - convert IO paths to use folio
   - reduce expensive checkpoint trigger frequency
   - allow F2FS_IPU_NOCACHE for pinned file
   - forcibly migrate to secure space for zoned device file pinning
   - get rid of buffer_head use
   - add write priority option based on zone UFS
   - get rid of online repair on corrupted directory

  Bug fixes:
   - fix to don't panic system for no free segment fault injection
   - fix to don't set SB_RDONLY in f2fs_handle_critical_error()
   - avoid unused block when dio write in LFS mode
   - compress: don't redirty sparse cluster during {,de}compress
   - check discard support for conventional zones
   - atomic: prevent atomic file from being dirtied before commit
   - atomic: fix to check atomic_file in f2fs ioctl interfaces
   - atomic: fix to forbid dio in atomic_file
   - atomic: fix to truncate pagecache before on-disk metadata truncation
   - atomic: create COW inode from parent dentry
   - atomic: fix to avoid racing w/ GC
   - atomic: require FMODE_WRITE for atomic write ioctls
   - fix to wait page writeback before setting gcing flag
   - fix to avoid racing in between read and OPU dio write, dio completion
   - fix several potential integer overflows in file offsets and dir_block_index
   - fix to avoid use-after-free in f2fs_stop_gc_thread()

  As usual, there are several code clean-ups and refactorings"

* tag 'f2fs-for-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (60 commits)
  f2fs: allow F2FS_IPU_NOCACHE for pinned file
  f2fs: forcibly migrate to secure space for zoned device file pinning
  f2fs: remove unused parameters
  f2fs: fix to don't panic system for no free segment fault injection
  f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()
  f2fs: add valid block ratio not to do excessive GC for one time GC
  f2fs: create gc_no_zoned_gc_percent and gc_boost_zoned_gc_percent
  f2fs: do FG_GC when GC boosting is required for zoned devices
  f2fs: increase BG GC migration window granularity when boosted for zoned devices
  f2fs: add reserved_segments sysfs node
  f2fs: introduce migration_window_granularity
  f2fs: make BG GC more aggressive for zoned devices
  f2fs: avoid unused block when dio write in LFS mode
  f2fs: fix to check atomic_file in f2fs ioctl interfaces
  f2fs: get rid of online repaire on corrupted directory
  f2fs: prevent atomic file from being dirtied before commit
  f2fs: get rid of page-&gt;index
  f2fs: convert read_node_page() to use folio
  f2fs: convert __write_node_page() to use folio
  f2fs: convert f2fs_write_data_page() to use folio
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull f2fs updates from Jaegeuk Kim:
 "The main changes include converting major IO paths to use folio, and
  adding various knobs to control GC more flexibly for Zoned devices.

  In addition, there are several patches to address corner cases of
  atomic file operations and better support for file pinning on zoned
  device.

  Enhancement:
   - add knobs to tune foreground/background GCs for Zoned devices
   - convert IO paths to use folio
   - reduce expensive checkpoint trigger frequency
   - allow F2FS_IPU_NOCACHE for pinned file
   - forcibly migrate to secure space for zoned device file pinning
   - get rid of buffer_head use
   - add write priority option based on zone UFS
   - get rid of online repair on corrupted directory

  Bug fixes:
   - fix to don't panic system for no free segment fault injection
   - fix to don't set SB_RDONLY in f2fs_handle_critical_error()
   - avoid unused block when dio write in LFS mode
   - compress: don't redirty sparse cluster during {,de}compress
   - check discard support for conventional zones
   - atomic: prevent atomic file from being dirtied before commit
   - atomic: fix to check atomic_file in f2fs ioctl interfaces
   - atomic: fix to forbid dio in atomic_file
   - atomic: fix to truncate pagecache before on-disk metadata truncation
   - atomic: create COW inode from parent dentry
   - atomic: fix to avoid racing w/ GC
   - atomic: require FMODE_WRITE for atomic write ioctls
   - fix to wait page writeback before setting gcing flag
   - fix to avoid racing in between read and OPU dio write, dio completion
   - fix several potential integer overflows in file offsets and dir_block_index
   - fix to avoid use-after-free in f2fs_stop_gc_thread()

  As usual, there are several code clean-ups and refactorings"

* tag 'f2fs-for-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (60 commits)
  f2fs: allow F2FS_IPU_NOCACHE for pinned file
  f2fs: forcibly migrate to secure space for zoned device file pinning
  f2fs: remove unused parameters
  f2fs: fix to don't panic system for no free segment fault injection
  f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()
  f2fs: add valid block ratio not to do excessive GC for one time GC
  f2fs: create gc_no_zoned_gc_percent and gc_boost_zoned_gc_percent
  f2fs: do FG_GC when GC boosting is required for zoned devices
  f2fs: increase BG GC migration window granularity when boosted for zoned devices
  f2fs: add reserved_segments sysfs node
  f2fs: introduce migration_window_granularity
  f2fs: make BG GC more aggressive for zoned devices
  f2fs: avoid unused block when dio write in LFS mode
  f2fs: fix to check atomic_file in f2fs ioctl interfaces
  f2fs: get rid of online repaire on corrupted directory
  f2fs: prevent atomic file from being dirtied before commit
  f2fs: get rid of page-&gt;index
  f2fs: convert read_node_page() to use folio
  f2fs: convert __write_node_page() to use folio
  f2fs: convert f2fs_write_data_page() to use folio
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs</title>
<updated>2024-09-23T16:35:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-23T16:35:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f8ffbc365f703d74ecca8ca787318d05bbee2bf7'/>
<id>f8ffbc365f703d74ecca8ca787318d05bbee2bf7</id>
<content type='text'>
Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull 'struct fd' updates from Al Viro:
 "Just the 'struct fd' layout change, with conversion to accessor
  helpers"

* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add struct fd constructors, get rid of __to_fd()
  struct fd: representation change
  introduce fd_file(), convert all accessors to it.
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: allow F2FS_IPU_NOCACHE for pinned file</title>
<updated>2024-09-23T15:42:13+00:00</updated>
<author>
<name>Jaegeuk Kim</name>
<email>jaegeuk@kernel.org</email>
</author>
<published>2024-09-14T21:44:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ae87b9c2dc9800e6ab52febd09341140599ff8e3'/>
<id>ae87b9c2dc9800e6ab52febd09341140599ff8e3</id>
<content type='text'>
This patch allows f2fs to submit bios of in-place writes on pinned file.

Reviewed-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch allows f2fs to submit bios of in-place writes on pinned file.

Reviewed-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: forcibly migrate to secure space for zoned device file pinning</title>
<updated>2024-09-13T16:37:00+00:00</updated>
<author>
<name>Daeho Jeong</name>
<email>daehojeong@google.com</email>
</author>
<published>2024-09-12T16:59:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5cc69a27abfa91abbb39fc584f82d6c867b60f47'/>
<id>5cc69a27abfa91abbb39fc584f82d6c867b60f47</id>
<content type='text'>
We need to migrate data blocks even though it is full to secure space
for zoned device file pinning.

Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices")
Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We need to migrate data blocks even though it is full to secure space
for zoned device file pinning.

Fixes: 9703d69d9d15 ("f2fs: support file pinning for zoned devices")
Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: remove unused parameters</title>
<updated>2024-09-12T14:42:03+00:00</updated>
<author>
<name>liuderong</name>
<email>liuderong@oppo.com</email>
</author>
<published>2024-09-11T02:40:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2af583afcf9d54b988b68d1033101e73edd72a9b'/>
<id>2af583afcf9d54b988b68d1033101e73edd72a9b</id>
<content type='text'>
Remove unused parameter segno from f2fs_usable_segs_in_sec.

Signed-off-by: liuderong &lt;liuderong@oppo.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove unused parameter segno from f2fs_usable_segs_in_sec.

Signed-off-by: liuderong &lt;liuderong@oppo.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to don't panic system for no free segment fault injection</title>
<updated>2024-09-11T03:38:14+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-09-10T01:16:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=65a6ce4726c27b45600303f06496fef46d00b57f'/>
<id>65a6ce4726c27b45600303f06496fef46d00b57f</id>
<content type='text'>
f2fs: fix to don't panic system for no free segment fault injection

syzbot reports a f2fs bug as below:

F2FS-fs (loop0): inject no free segment in get_new_segment of __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
F2FS-fs (loop0): Stopped filesystem due to reason: 7
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2748!
CPU: 0 UID: 0 PID: 5109 Comm: syz-executor304 Not tainted 6.11.0-rc6-syzkaller-00363-g89f5e14d05b4 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836
Call Trace:
 __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
 f2fs_allocate_new_section fs/f2fs/segment.c:3181 [inline]
 f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3195
 f2fs_expand_inode_data+0x5d6/0xbb0 fs/f2fs/file.c:1799
 f2fs_fallocate+0x448/0x960 fs/f2fs/file.c:1903
 vfs_fallocate+0x553/0x6c0 fs/open.c:334
 do_vfs_ioctl+0x2592/0x2e50 fs/ioctl.c:886
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836

The root cause is when we inject no free segment fault into f2fs,
we should not panic system, fix it.

Fixes: 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT")
Reported-by: syzbot+341e5f32ebafbb46b81c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/000000000000f0ee5b0621ab694b@google.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
f2fs: fix to don't panic system for no free segment fault injection

syzbot reports a f2fs bug as below:

F2FS-fs (loop0): inject no free segment in get_new_segment of __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
F2FS-fs (loop0): Stopped filesystem due to reason: 7
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2748!
CPU: 0 UID: 0 PID: 5109 Comm: syz-executor304 Not tainted 6.11.0-rc6-syzkaller-00363-g89f5e14d05b4 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836
Call Trace:
 __allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3167
 f2fs_allocate_new_section fs/f2fs/segment.c:3181 [inline]
 f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3195
 f2fs_expand_inode_data+0x5d6/0xbb0 fs/f2fs/file.c:1799
 f2fs_fallocate+0x448/0x960 fs/f2fs/file.c:1903
 vfs_fallocate+0x553/0x6c0 fs/open.c:334
 do_vfs_ioctl+0x2592/0x2e50 fs/ioctl.c:886
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0010:get_new_segment fs/f2fs/segment.c:2748 [inline]
RIP: 0010:new_curseg+0x1f61/0x1f70 fs/f2fs/segment.c:2836

The root cause is when we inject no free segment fault into f2fs,
we should not panic system, fix it.

Fixes: 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT")
Reported-by: syzbot+341e5f32ebafbb46b81c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/000000000000f0ee5b0621ab694b@google.com
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()</title>
<updated>2024-09-11T03:36:43+00:00</updated>
<author>
<name>Chao Yu</name>
<email>chao@kernel.org</email>
</author>
<published>2024-09-10T03:07:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=930c6ab93492c4b15436524e704950b364b2930c'/>
<id>930c6ab93492c4b15436524e704950b364b2930c</id>
<content type='text'>
syzbot reports a f2fs bug as below:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 58 at kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177
CPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 Not tainted 6.10.0-syzkaller-12562-g1722389b0d86 #0
Workqueue: events destroy_super_work
RIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177
Call Trace:
 percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42
 destroy_super_work+0xec/0x130 fs/super.c:282
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

As Christian Brauner pointed out [1]: the root cause is f2fs sets
SB_RDONLY flag in internal function, rather than setting the flag
covered w/ sb-&gt;s_umount semaphore via remount procedure, then below
race condition causes this bug:

- freeze_super()
 - sb_wait_write(sb, SB_FREEZE_WRITE)
 - sb_wait_write(sb, SB_FREEZE_PAGEFAULT)
 - sb_wait_write(sb, SB_FREEZE_FS)
					- f2fs_handle_critical_error
					 - sb-&gt;s_flags |= SB_RDONLY
- thaw_super
 - thaw_super_locked
  - sb_rdonly() is true, so it skips
    sb_freeze_unlock(sb, SB_FREEZE_FS)
  - deactivate_locked_super

Since f2fs has almost the same logic as ext4 [2] when handling critical
error in filesystem if it mounts w/ errors=remount-ro option:
- set CP_ERROR_FLAG flag which indicates filesystem is stopped
- record errors to superblock
- set SB_RDONLY falg
Once we set CP_ERROR_FLAG flag, all writable interfaces can detect the
flag and stop any further updates on filesystem. So, it is safe to not
set SB_RDONLY flag, let's remove the logic and keep in line w/ ext4 [3].

[1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner
[2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3
[3] https://lore.kernel.org/linux-ext4/20240805201241.27286-1-jack@suse.cz

Fixes: b62e71be2110 ("f2fs: support errors=remount-ro|continue|panic mountoption")
Reported-by: syzbot+20d7e439f76bbbd863a7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000b90a8e061e21d12f@google.com/
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot reports a f2fs bug as below:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 58 at kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177
CPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 Not tainted 6.10.0-syzkaller-12562-g1722389b0d86 #0
Workqueue: events destroy_super_work
RIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177
Call Trace:
 percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42
 destroy_super_work+0xec/0x130 fs/super.c:282
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

As Christian Brauner pointed out [1]: the root cause is f2fs sets
SB_RDONLY flag in internal function, rather than setting the flag
covered w/ sb-&gt;s_umount semaphore via remount procedure, then below
race condition causes this bug:

- freeze_super()
 - sb_wait_write(sb, SB_FREEZE_WRITE)
 - sb_wait_write(sb, SB_FREEZE_PAGEFAULT)
 - sb_wait_write(sb, SB_FREEZE_FS)
					- f2fs_handle_critical_error
					 - sb-&gt;s_flags |= SB_RDONLY
- thaw_super
 - thaw_super_locked
  - sb_rdonly() is true, so it skips
    sb_freeze_unlock(sb, SB_FREEZE_FS)
  - deactivate_locked_super

Since f2fs has almost the same logic as ext4 [2] when handling critical
error in filesystem if it mounts w/ errors=remount-ro option:
- set CP_ERROR_FLAG flag which indicates filesystem is stopped
- record errors to superblock
- set SB_RDONLY falg
Once we set CP_ERROR_FLAG flag, all writable interfaces can detect the
flag and stop any further updates on filesystem. So, it is safe to not
set SB_RDONLY flag, let's remove the logic and keep in line w/ ext4 [3].

[1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner
[2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3
[3] https://lore.kernel.org/linux-ext4/20240805201241.27286-1-jack@suse.cz

Fixes: b62e71be2110 ("f2fs: support errors=remount-ro|continue|panic mountoption")
Reported-by: syzbot+20d7e439f76bbbd863a7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000b90a8e061e21d12f@google.com/
Cc: Jan Kara &lt;jack@suse.cz&gt;
Cc: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Chao Yu &lt;chao@kernel.org&gt;
Reviewed-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>f2fs: add valid block ratio not to do excessive GC for one time GC</title>
<updated>2024-09-11T03:33:08+00:00</updated>
<author>
<name>Daeho Jeong</name>
<email>daehojeong@google.com</email>
</author>
<published>2024-09-09T22:19:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e791d00bd06cb2d3a10afa43e57f6364931d0ada'/>
<id>e791d00bd06cb2d3a10afa43e57f6364931d0ada</id>
<content type='text'>
We need to introduce a valid block ratio threshold not to trigger
excessive GC for zoned deivces. The initial value of it is 95%. So, F2FS
will stop the thread from intiating GC for sections having valid blocks
exceeding the ratio.

Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We need to introduce a valid block ratio threshold not to trigger
excessive GC for zoned deivces. The initial value of it is 95%. So, F2FS
will stop the thread from intiating GC for sections having valid blocks
exceeding the ratio.

Signed-off-by: Daeho Jeong &lt;daehojeong@google.com&gt;
Reviewed-by: Chao Yu &lt;chao@kernel.org&gt;
Signed-off-by: Jaegeuk Kim &lt;jaegeuk@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
