tree 6a420bb5959128a3d269261c0024973c1ed99c09
parent cbb69e548a927b4ec2933e1033f955d88004db25
author Nikita Ioffe <ioffe@google.com> 1591963185 +0100
committer Nikita Ioffe <ioffe@google.com> 1592405905 +0100

Configure read ahead for fuse mounts

For fuse read ahead can be configured by writing a value to the
/sys/class/bdi/{MAJOR}:{MINOR}/read_ahead_kb file.

There are several different ways of getting {MAJOR}:{MINOR} values of
the filesystem:

* Look at st_dev of stat("/mnt/user/0/emulated").
* Parse /proc/self/mountinfo.

Stat'ing approach is used since it's easier to implement.

Bug: 157982297
Test: atest vold_tests
Test: adb shell cat /proc/self/mountinfo to get MAJOR:MINOR
Test: adb shell cat /sys/class/bdi/{MAJOR}:{MINOR}/read_ahead_kb
Test: created public volume, checked it's read_ahead_kb is also 256
Change-Id: Id0c149c4af1ceabf3afc33b4100563a512b38316