• Jiaying Zhang's avatar
    ext4: use ext4_get_block_write in buffer write · 744692dc
    Jiaying Zhang authored
    Allocate uninitialized extent before ext4 buffer write and
    convert the extent to initialized after io completes.
    The purpose is to make sure an extent can only be marked
    initialized after it has been written with new data so
    we can safely drop the i_mutex lock in ext4 DIO read without
    exposing stale data. This helps to improve multi-thread DIO
    read performance on high-speed disks.
    
    Skip the nobh and data=journal mount cases to make things simple for now.
    Signed-off-by: default avatarJiaying Zhang <jiayingz@google.com>
    Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
    744692dc
ext4_jbd2.h 10.2 KB