F2FS
Flash-Friendly File System.

# F2FS superblock ve checkpoint bilgisi
dump.f2fs -d 1 /dev/mmcblk1p2

# Örnek çıktı (önemli alanlar):
# Info: checkpoint state = 5 : crc consistent unmount
# Info: current valid block count = 52428
# Info: BIO count = 0

# sysfs üzerinden anlık istatistik
cat /sys/fs/f2fs/mmcblk1p2/stat

# Temel format
mkfs.f2fs /dev/mmcblk1p2

# Tüm seçeneklerle (üretim)
mkfs.f2fs \
  -l "data-part" \
  -O encrypt \
  -O extra_attr \
  -O compression \
  -t 1 \
  /dev/mmcblk1p2
# -l : etiket
# -O encrypt : dosya bazlı şifreleme desteği (fscrypt)
# -O extra_attr : genişletilmiş inode attribute
# -O compression : dosya bazlı sıkıştırma (LZ4/zstd)
# -t 1 : trim (discard) desteği etkin

# eMMC provision üretim scripti
mkfs.f2fs \
  -a 1 \
  -s 1 \
  -z 1 \
  -l "userdata" \
  -O encrypt,extra_attr,compression \
  /dev/mmcblk0p5
# -a : segs_per_sec (1 = segment=section)
# -s : secs_per_zone
# -z : zone sayısı

# /etc/fstab — üretim gömülü sistem için
UUID=1234abcd  /data  f2fs  defaults,discard,lazytime,nodiratime,background_gc=on  0  2

# /tmp için tmpfs ile birlikte (F2FS'i korur)
tmpfs  /tmp  tmpfs  defaults,noatime,mode=1777,size=64M  0  0

# Anlık mount test
mount -t f2fs -o discard,lazytime,background_gc=on \
  /dev/mmcblk1p2 /data

# Mevcut mount seçeneklerini göster
cat /proc/mounts | grep f2fs

# F2FS sysfs dizini (mmcblk1p2 mount edilmiş)
ls /sys/fs/f2fs/mmcblk1p2/

# GC ayarları
cat /sys/fs/f2fs/mmcblk1p2/gc_min_sleep_time     # ms cinsinden
cat /sys/fs/f2fs/mmcblk1p2/gc_max_sleep_time
cat /sys/fs/f2fs/mmcblk1p2/gc_idle_interval

# Agresif GC etkinleştir (boş alan kritik)
echo 1 > /sys/fs/f2fs/mmcblk1p2/gc_urgent
echo 50  > /sys/fs/f2fs/mmcblk1p2/gc_min_sleep_time
echo 500 > /sys/fs/f2fs/mmcblk1p2/gc_max_sleep_time

# Normal mod (düşük yazma baskısı)
echo 0    > /sys/fs/f2fs/mmcblk1p2/gc_urgent
echo 10000 > /sys/fs/f2fs/mmcblk1p2/gc_min_sleep_time
echo 30000 > /sys/fs/f2fs/mmcblk1p2/gc_max_sleep_time

# Manuel GC tetikle (maintenance penceresi)
echo 1 > /sys/fs/f2fs/mmcblk1p2/gc_urgent
sleep 30
echo 0 > /sys/fs/f2fs/mmcblk1p2/gc_urgent

# GC istatistiklerini izle
cat /sys/fs/f2fs/mmcblk1p2/stat | grep -i gc

# dump.f2fs ile detaylı istatistik
dump.f2fs -s /dev/mmcblk1p2

# Seçili segment bilgisi
dump.f2fs -S /dev/mmcblk1p2 | head -50

# iostat ile GC sırasında I/O izle
iostat -x mmcblk1 1 30

# 1. Mount-time discard (anlık — her silmede TRIM gönderir)
mount -t f2fs -o discard /dev/mmcblk1p2 /data

# 2. Periyodik fstrim (batch — daha az overhead)
# /etc/cron.d/fstrim veya systemd timer ile
fstrim -av   # tüm mount edilmiş FS'lere TRIM gönder
fstrim -v /data   # sadece /data

# Systemd weekly timer (fstrim.timer)
systemctl enable --now fstrim.timer
systemctl status fstrim.timer

# 3. F2FS background discard (önerilen — batch)
# /sys/fs/f2fs parametreleri
cat /sys/fs/f2fs/mmcblk1p2/discard_granularity
echo 4 > /sys/fs/f2fs/mmcblk1p2/discard_granularity  # 4*segment = 8MB

# eMMC discard desteğini kontrol et
cat /sys/block/mmcblk1/queue/discard_max_bytes
cat /sys/block/mmcblk1/queue/discard_granularity

# /etc/systemd/system/fstrim-data.service
[Unit]
Description=F2FS veri partisyon TRIM
After=data.mount

[Service]
Type=oneshot
ExecStart=/sbin/fstrim -v /data
ExecStart=/sbin/fstrim -v /var

# /etc/systemd/system/fstrim-data.timer
[Unit]
Description=Haftalık F2FS TRIM

[Timer]
OnCalendar=weekly
Persistent=true

[Install]
WantedBy=timers.target

# eMMC write counter (JEDEC Health registers)
mmc extcsd read /dev/mmcblk0 | grep -i life

# F2FS istatistiklerinden WAF tahmini
cat /sys/fs/f2fs/mmcblk1p2/stat
# GC: data segs written vs user data written

# fio ile gerçekçi WAF testi
fio --filename=/data/waf_test \
  --rw=randwrite \
  --bs=4k \
  --ioengine=libaio \
  --iodepth=32 \
  --size=256M \
  --numjobs=4 \
  --time_based \
  --runtime=300 \
  --name=waf_randwrite \
  --group_reporting

# Temel kontrol (read-only)
fsck.f2fs /dev/mmcblk1p2

# Onarım modunda çalıştır
fsck.f2fs -f -y /dev/mmcblk1p2
# -f : zorla kontrol
# -y : tüm soruları evet cevapla (otomatik onarım)

# Verbose çıktı
fsck.f2fs -v /dev/mmcblk1p2

# Hızlı mod (sadece metadata)
fsck.f2fs -q /dev/mmcblk1p2

# Boot öncesi initramfs'te (systemd-fsck yerine)
# /etc/fstab'da son alan 2 (nonzero = fsck etkin)

# Superblock bilgisi
dump.f2fs -d 1 /dev/mmcblk1p2

# Segment bilgisi
dump.f2fs -s /dev/mmcblk1p2 | head -30

# Node bilgisi (ino numarası ver)
dump.f2fs -n 3 /dev/mmcblk1p2

# Tüm inode listesi
dump.f2fs -i /dev/mmcblk1p2 | head -20

# Checkpoint bilgisi
dump.f2fs -c /dev/mmcblk1p2

# Disk birleştirme (online — mount edilmişken)
defrag.f2fs /dev/mmcblk1p2

# Spesifik bir dosyayı birleştir
defrag.f2fs -f /data/büyük_dosya.img /dev/mmcblk1p2

# Boyut küçültme (offline — mount edilmemişken)
resize.f2fs -t /dev/mmcblk1p2     # hedef boyutu yazdır
resize.f2fs /dev/mmcblk1p2        # maksimum boyuta büyüt

# sload.f2fs — host'ta imaj içine dosya kopyala
# (üretim imaj oluşturma için)
sload.f2fs -f /path/to/rootfs -t / /dev/loop0

# mkfs + sload ile imaj oluşturma
dd if=/dev/zero bs=1M count=512 of=data.img
mkfs.f2fs data.img
sload.f2fs -f /path/to/data -t / data.img

# eMMC bölümle (sgdisk)
sgdisk --zap-all /dev/mmcblk1
sgdisk --new=1:2048:133119   --typecode=1:0700 --change-name=1:"boot"  /dev/mmcblk1
sgdisk --new=2:133120:3278847 --typecode=2:8300 --change-name=2:"rootfs" /dev/mmcblk1
sgdisk --new=3:3278848:7472127 --typecode=3:8300 --change-name=3:"data"  /dev/mmcblk1
sgdisk --new=4:7472128:0     --typecode=4:8300 --change-name=4:"var"   /dev/mmcblk1

# F2FS formatla
mkfs.f2fs -l "bbb-data" -O encrypt,extra_attr,compression -t 1 /dev/mmcblk1p3
mkfs.f2fs -l "bbb-var"  -O extra_attr -t 1 /dev/mmcblk1p4

# Mount test
mount -t f2fs -o discard,lazytime,background_gc=on /dev/mmcblk1p3 /data
df -h /data

# /etc/fstab
UUID=$(blkid -s UUID -o value /dev/mmcblk1p3)
$UUID  /data  f2fs  defaults,discard,lazytime,nodiratime,background_gc=on  0  2

UUID=$(blkid -s UUID -o value /dev/mmcblk1p4)
$UUID  /var   f2fs  defaults,discard,lazytime,nodiratime,background_gc=on  0  2

# tmpfs /tmp
tmpfs  /tmp  tmpfs  defaults,noatime,mode=1777,size=32M  0  0

#!/bin/bash
# F2FS GC parametrelerini disk doluluk oranına göre ayarla
set -e

F2FS_MOUNTS=( /data /var )

tune_gc() {
    local mountpoint="$1"
    local dev
    dev=$(findmnt -n -o SOURCE "$mountpoint" | sed 's|/dev/||')
    local sysfs="/sys/fs/f2fs/${dev}"

    [ -d "$sysfs" ] || return

    # Kullanım yüzdesi
    local usage
    usage=$(df "$mountpoint" | awk 'NR==2{gsub(/%/,""); print $5}')

    if [ "$usage" -ge 85 ]; then
        # Kritik — agresif GC
        echo 1 > "$sysfs/gc_urgent"
        echo 100  > "$sysfs/gc_min_sleep_time"
        echo 1000  > "$sysfs/gc_max_sleep_time"
        logger "F2FS GC: $mountpoint %$usage dolu — agresif GC modu"
    elif [ "$usage" -ge 70 ]; then
        # Uyarı — orta GC
        echo 0 > "$sysfs/gc_urgent"
        echo 1000  > "$sysfs/gc_min_sleep_time"
        echo 10000  > "$sysfs/gc_max_sleep_time"
        logger "F2FS GC: $mountpoint %$usage dolu — orta GC modu"
    else
        # Normal — yavaş GC
        echo 0 > "$sysfs/gc_urgent"
        echo 10000  > "$sysfs/gc_min_sleep_time"
        echo 30000  > "$sysfs/gc_max_sleep_time"
    fi
}

for mp in "{{F2FS_MOUNTS[@]}}"; do
    tune_gc "$mp"
done

#!/bin/bash
# /usr/local/sbin/emmc-health-check.sh

DEVICE="/dev/mmcblk1"
LOGFILE="/data/logs/emmc-health.log"

check_health() {
    local ts
    ts=$(date '+%Y-%m-%d %H:%M:%S')

    # eMMC yaşam süresi tahminleri
    local life_a life_b eol
    life_a=$(mmc extcsd read "$DEVICE" 2>/dev/null | \
        grep "DEVICE_LIFE_TIME_EST_TYP_A" | awk '{print $NF}')
    life_b=$(mmc extcsd read "$DEVICE" 2>/dev/null | \
        grep "DEVICE_LIFE_TIME_EST_TYP_B" | awk '{print $NF}')
    eol=$(mmc extcsd read "$DEVICE" 2>/dev/null | \
        grep "PRE_EOL_INFO" | awk '{print $NF}')

    echo "$ts LIFE_A=$life_a LIFE_B=$life_b EOL=$eol" >> "$LOGFILE"

    # EOL uyarısı
    if [ "$eol" = "0x02" ]; then
        logger -p user.warning "eMMC EOL UYARI: $DEVICE yıpranma uyarısı!"
    elif [ "$eol" = "0x03" ]; then
        logger -p user.crit "eMMC EOL KRİTİK: $DEVICE acil değişim!"
    fi
}

check_health