В чем разница между / sys / class / block и / sys / block

469
Wimateeka

Когда я делаю любой lsиз dir, их содержание очень похоже

/ SYS / класс / блок

$ ls /sys/class/block dm-0 dm-3 loop1 loop4 loop7 ram10 ram13 ram2 ram5 ram8 sda1 sda4 dm-1 dm-4 loop2 loop5 ram0 ram11 ram14 ram3 ram6 ram9 sda2 sda5 dm-2 loop0 loop3 loop6 ram1 ram12 ram15 ram4 ram7 sda sda3 sda6  ls -lah /sys/class/block/ total 0 drwxr-xr-x 2 root root 0 Apr 23 16:08 . drwxr-xr-x 52 root root 0 Apr 23 16:08 .. lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-0 -> ../../devices/virtual/block/dm-0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-1 -> ../../devices/virtual/block/dm-1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-2 -> ../../devices/virtual/block/dm-2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-3 -> ../../devices/virtual/block/dm-3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-4 -> ../../devices/virtual/block/dm-4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop0 -> ../../devices/virtual/block/loop0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop1 -> ../../devices/virtual/block/loop1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop2 -> ../../devices/virtual/block/loop2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop3 -> ../../devices/virtual/block/loop3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop4 -> ../../devices/virtual/block/loop4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop5 -> ../../devices/virtual/block/loop5 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop6 -> ../../devices/virtual/block/loop6 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop7 -> ../../devices/virtual/block/loop7 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram0 -> ../../devices/virtual/block/ram0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram1 -> ../../devices/virtual/block/ram1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram10 -> ../../devices/virtual/block/ram10 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram11 -> ../../devices/virtual/block/ram11 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram12 -> ../../devices/virtual/block/ram12 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram13 -> ../../devices/virtual/block/ram13 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram14 -> ../../devices/virtual/block/ram14 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram15 -> ../../devices/virtual/block/ram15 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram2 -> ../../devices/virtual/block/ram2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram3 -> ../../devices/virtual/block/ram3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram4 -> ../../devices/virtual/block/ram4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram5 -> ../../devices/virtual/block/ram5 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram6 -> ../../devices/virtual/block/ram6 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram7 -> ../../devices/virtual/block/ram7 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram8 -> ../../devices/virtual/block/ram8 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram9 -> ../../devices/virtual/block/ram9 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda1 -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda2 -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda3 -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda4 -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda5 -> ../../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda5 lrwxrwxrwx 1 r

/ SYS / блок /

$ ls /sys/block/ dm-0 dm-3 loop1 loop4 loop7 ram10 ram13 ram2 ram5 ram8 dm-1 dm-4 loop2 loop5 ram0 ram11 ram14 ram3 ram6 ram9 dm-2 loop0 loop3 loop6 ram1 ram12 ram15 ram4 ram7 sda  $ ls -lah /sys/block/ drwxr-xr-x 2 root root 0 Apr 23 16:08 . dr-xr-xr-x 13 root root 0 Apr 23 16:08 .. lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-0 -> ../devices/virtual/block/dm-0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-1 -> ../devices/virtual/block/dm-1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-2 -> ../devices/virtual/block/dm-2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-3 -> ../devices/virtual/block/dm-3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 dm-4 -> ../devices/virtual/block/dm-4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop0 -> ../devices/virtual/block/loop0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop1 -> ../devices/virtual/block/loop1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop2 -> ../devices/virtual/block/loop2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop3 -> ../devices/virtual/block/loop3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop4 -> ../devices/virtual/block/loop4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop5 -> ../devices/virtual/block/loop5 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop6 -> ../devices/virtual/block/loop6 lrwxrwxrwx 1 root root 0 Apr 23 16:08 loop7 -> ../devices/virtual/block/loop7 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram0 -> ../devices/virtual/block/ram0 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram1 -> ../devices/virtual/block/ram1 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram10 -> ../devices/virtual/block/ram10 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram11 -> ../devices/virtual/block/ram11 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram12 -> ../devices/virtual/block/ram12 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram13 -> ../devices/virtual/block/ram13 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram14 -> ../devices/virtual/block/ram14 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram15 -> ../devices/virtual/block/ram15 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram2 -> ../devices/virtual/block/ram2 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram3 -> ../devices/virtual/block/ram3 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram4 -> ../devices/virtual/block/ram4 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram5 -> ../devices/virtual/block/ram5 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram6 -> ../devices/virtual/block/ram6 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram7 -> ../devices/virtual/block/ram7 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram8 -> ../devices/virtual/block/ram8 lrwxrwxrwx 1 root root 0 Apr 23 16:08 ram9 -> ../devices/virtual/block/ram9 lrwxrwxrwx 1 root root 0 Apr 23 16:08 sda -> ../devices/pci0000:00/0000:00:1f.2/ata1/host0/target0:0:0/0:0:0:0/block/sda

Они оба имеют многочисленные символические ссылки на одно и то же место. Единственное различие, которое я вижу, /sys/class/block/имеет sdaи sda1через sda6пока /sys/block/имеет только sda.

В чем главное отличие /sys/block/а /sys/class/block?

1

1 ответ на вопрос

3
grawity

Последнее существует по причинам совместимости, потому что sysfs изначально имел выделенный код для блочных устройств, но позже они стали просто еще одним «классом». Смотрите коммит v2.6.24-158-gedfaa7c36574:

Ядро драйвера: конвертировать блок из необработанных kobjects в основные устройства

Это перемещает блочные устройства в / sys / class / block. Он создаст плоский список всех блочных устройств с дисками и разделами в одном каталоге. Для совместимости / sys / block создан и содержит символические ссылки на диски.

(Найдено с помощью tig blame drivers/base/class.c)

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