kernel/git/stable/linux.git/fs/f2fs/sysfs.c, branch linux-7.2.y

f2fs: protect critical_task_priority updates with s_umount

2026-09-11T09:51:19+00:00

commit 8e4692c6c165e81b2cbb847d8da4b45a53483b33 upstream. The sysfs store path already takes s_umount for GC thread control entries, and ckpt_thread_ioprio is covered as well. critical_task_priority also updates checkpoint or GC kthread scheduling state, but it is not covered by that serialization. It can race with remount or teardown paths that are stopping those threads. Protect critical_task_priority sysfs writes with s_umount too. Fixes: 52190933c37a ("f2fs: sysfs: introduce critical_task_priority") Cc: stable@kernel.org Signed-off-by: Wenjie Qi Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: avoid NULL checkpoint thread access in sysfs

2026-09-11T09:51:18+00:00

commit 5cb33b00c8fbb6e8f1fa3d281c3036d5f7c7c41f upstream. checkpoint_merge can be enabled even when no checkpoint merge thread is running. A read-only mount is one case: f2fs does not start f2fs_issue_ckpt there, but ckpt_thread_ioprio is still writable through sysfs. The ckpt_thread_ioprio store path updates the saved ioprio value and, when checkpoint_merge is enabled, calls set_task_ioprio() for the checkpoint thread. If cprc->f2fs_issue_ckpt is NULL, that dereferences a NULL task pointer. Protect ckpt_thread_ioprio sysfs writes with s_umount as well, so the checkpoint thread cannot disappear under the store path while updating its ioprio. Fixes: e65920661708 ("f2fs: add ckpt_thread_ioprio sysfs node") Cc: stable@kernel.org Signed-off-by: Wenjie Qi Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: embed f2fs_gc_kthread in f2fs_sb_info

2026-09-11T09:51:18+00:00

commit 3d7bca9d583793bb7d0bac0d95a24ddd2e129eed upstream. Instead of allocating f2fs_gc_kthread dynamically, embed it in f2fs_sb_info. This simplifies lifetime management and prepares for fixing race conditions during teardown. - __sbi_store - remount|shutdown - f2fs_stop_gc_thread - access sbi->gc_thread - sbi->gc_thread = NULL - access sbi->gc_thread->f2fs_gc_task Fixes: 52190933c37a ("f2fs: sysfs: introduce critical_task_priority") Fixes: 7950e9ac638e ("f2fs: stop gc/discard thread after fs shutdown") Cc: stable@kernel.org Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: support to report fserror

2026-05-22T03:49:06+00:00

This patch supports to report fserror, it provides another way to let userspace to monitor filesystem level error. In addition, it exports /sys/fs/f2fs/features/fserror once f2fs kernel module start to support the new feature, then generic/791 of fstests can notice the feature, and verify validation of fserror report. Cc: Darrick J. Wong Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix uninitialized kobject put in f2fs_init_sysfs()

2026-04-13T22:53:17+00:00

In f2fs_init_sysfs(), all failure paths after kset_register() jump to put_kobject, which unconditionally releases both f2fs_tune and f2fs_feat. If kobject_init_and_add(&f2fs_feat, ...) fails, f2fs_tune has not been initialized yet, so calling kobject_put(&f2fs_tune) is invalid. Fix this by splitting the unwind path so each error path only releases objects that were successfully initialized. Fixes: a907f3a68ee26ba4 ("f2fs: add a sysfs entry to reclaim POSIX_FADV_NOREUSE pages") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: protect extension_list reading with sb_lock in f2fs_sbi_show()

2026-04-13T22:53:00+00:00

In f2fs_sbi_show(), the extension_list, extension_count and hot_ext_count are read without holding sbi->sb_lock. If a concurrent sysfs store modifies the extension list via f2fs_update_extension_list(), the show path may read inconsistent count and array contents, potentially leading to out-of-bounds access or displaying stale data. Fix this by holding sb_lock around the entire extension list read and format operation. Fixes: b6a06cbbb5f7 ("f2fs: support hot file extension") Signed-off-by: Yongpeng Yang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: Add defrag_blocks sysfs node

2026-03-24T17:20:59+00:00

Add the defrag_blocks sysfs node to track the amount of data blocks moved during filesystem defragmentation. Signed-off-by: Sheng Yong Signed-off-by: liujinbao1 Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: sysfs: introduce critical_task_priority

2026-02-10T20:53:21+00:00

This patch introduces /sys/fs/f2fs//critical_task_priority, w/ this new sysfs interface, we can tune priority of f2fs_ckpt thread and f2fs_gc thread. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix lock priority inversion issue

2026-01-31T03:24:39+00:00

If userspace thread has held f2fs rw semaphore, due to its low priority, it could be runnable or preempted state for long time, during the time, it will block high priority thread which is trying to grab the same rw semaphore, e.g. cp_rwsem, io_rwsem... To fix such issue, let's detect thread's priority when it tries to grab f2fs_rwsem lock, if the priority is lower than a priority threshold, let's uplift the priority before it enters into critical region of lock, and restore the priority after it leaves from critical region. Meanwhile, introducing two new sysfs nodes: - /sys/fs/f2fs//adjust_lock_priority, it is used to control whether the functionality is enable or not. ========== ================== Flag_Value Flag_Description ========== ================== 0x00000000 Disabled (default) 0x00000001 cp_rwsem 0x00000002 node_change 0x00000004 node_write 0x00000008 gc_lock 0x00000010 cp_global 0x00000020 io_rwsem ========== ================== - /sys/fs/f2fs//lock_duration_priority, it is used to control priority threshold. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to show simulate_lock_timeout correctly

2026-01-27T02:45:58+00:00

Commit d36de29f4bb5 ("f2fs: sysfs: introduce inject_lock_timeout") introduces a bug as below, fix it. cat /sys/fs/f2fs/vdx/inject_lock_timeout s/fs/f2fs/vdx/inject_lock_timeout: Invalid argument Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim