On Wed, 16 Apr 2025, Chao Yu wrote:

This patch adds a new sysfs entry /sys/fs/f2fs/<disk>/encoding_flags, it is a read-only entry to show the value of sb.s_encoding_flags, the value is hexadecimal.

=========================== ========== Flag_Name Flag_Value =========================== ========== SB_ENC_STRICT_MODE_FL 0x00000001 SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002 =========================== ==========

case#1 mkfs.f2fs -f -O casefold -C utf8:strict /dev/vda mount /dev/vda /mnt/f2fs cat /sys/fs/f2fs/vda/encoding_flags 1

case#2 mkfs.f2fs -f -O casefold -C utf8 /dev/vda fsck.f2fs --nolinear-lookup=1 /dev/vda mount /dev/vda /mnt/f2fs cat /sys/fs/f2fs/vda/encoding_flags 2

Signed-off-by: Chao Yu chao@kernel.org

Documentation/ABI/testing/sysfs-fs-f2fs | 13 +++++++++++++ fs/f2fs/sysfs.c | 9 +++++++++ 2 files changed, 22 insertions(+)

This patch, commit 617e0491abe4 ("f2fs: sysfs: export linear_lookup in features directory") upstream, needs to find its way into all Stable branches containing upstream commit 91b587ba79e1 ("f2fs: Introduce linear search for dentries"), which is essentially linux-5.15.y and newer.

stable/linux-5.4.y: MISSING: f2fs: Introduce linear search for dentries MISSING: f2fs: sysfs: export linear_lookup in features directory

stable/linux-5.10.y: MISSING: f2fs: Introduce linear search for dentries MISSING: f2fs: sysfs: export linear_lookup in features directory

stable/linux-5.15.y: b0938ffd39ae f2fs: Introduce linear search for dentries [5.15.179] MISSING: f2fs: sysfs: export linear_lookup in features directory

stable/linux-6.1.y: de605097eb17 f2fs: Introduce linear search for dentries [6.1.129] MISSING: f2fs: sysfs: export linear_lookup in features directory

stable/linux-6.6.y: 0bf2adad03e1 f2fs: Introduce linear search for dentries [6.6.76] MISSING: f2fs: sysfs: export linear_lookup in features directory

stable/linux-6.12.y: 00d1943fe46d f2fs: Introduce linear search for dentries [6.12.13] MISSING: f2fs: sysfs: export linear_lookup in features directory

mainline: 91b587ba79e1 f2fs: Introduce linear search for dentries 617e0491abe4 f2fs: sysfs: export linear_lookup in features directory

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs index 59adb7dc6f9e..0dbe6813b709 100644 --- a/Documentation/ABI/testing/sysfs-fs-f2fs +++ b/Documentation/ABI/testing/sysfs-fs-f2fs @@ -846,3 +846,16 @@ Description: For several zoned storage devices, vendors will provide extra space reserved_blocks. However, it is not enough, since this extra space should not be shown to users. So, with this new sysfs node, we can hide the space by substracting reserved_blocks from total bytes. + +What: /sys/fs/f2fs/<disk>/encoding_flags +Date: April 2025 +Contact: "Chao Yu" chao@kernel.org +Description: This is a read-only entry to show the value of sb.s_encoding_flags, the + value is hexadecimal. + + =========================== ========== + Flag_Name Flag_Value + =========================== ========== + SB_ENC_STRICT_MODE_FL 0x00000001 + SB_ENC_NO_COMPAT_FALLBACK_FL 0x00000002 + =========================== ========== diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 3a3485622691..cf98c5cbb98a 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -274,6 +274,13 @@ static ssize_t encoding_show(struct f2fs_attr *a, return sysfs_emit(buf, "(none)\n"); } +static ssize_t encoding_flags_show(struct f2fs_attr *a, + struct f2fs_sb_info *sbi, char *buf) +{ + return sysfs_emit(buf, "%x\n", + le16_to_cpu(F2FS_RAW_SUPER(sbi)->s_encoding_flags)); +} + static ssize_t mounted_time_sec_show(struct f2fs_attr *a, struct f2fs_sb_info *sbi, char *buf) { @@ -1158,6 +1165,7 @@ F2FS_GENERAL_RO_ATTR(features); F2FS_GENERAL_RO_ATTR(current_reserved_blocks); F2FS_GENERAL_RO_ATTR(unusable); F2FS_GENERAL_RO_ATTR(encoding); +F2FS_GENERAL_RO_ATTR(encoding_flags); F2FS_GENERAL_RO_ATTR(mounted_time_sec); F2FS_GENERAL_RO_ATTR(main_blkaddr); F2FS_GENERAL_RO_ATTR(pending_discard); @@ -1270,6 +1278,7 @@ static struct attribute *f2fs_attrs[] = { ATTR_LIST(reserved_blocks), ATTR_LIST(current_reserved_blocks), ATTR_LIST(encoding), + ATTR_LIST(encoding_flags), ATTR_LIST(mounted_time_sec), #ifdef CONFIG_F2FS_STAT_FS ATTR_LIST(cp_foreground_calls), -- 2.49.0