tree 66d98ac24b6959a78618b1706f156f8f76614ad8
parent a7ffdbe22cecaed59b5d76a5f003d68907d64240
author Jaegeuk Kim <jaegeuk@kernel.org> 1410393182 -0700
committer Jaegeuk Kim <jaegeuk@kernel.org> 1410865844 -0700

f2fs: give an option to enable in-place-updates during fsync to users

If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
only starts to try in-place-updates.
And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
keeps out-of-order manner. Otherwise, it triggers in-place-updates.

This may be used by storage showing very high random write performance.

For example, it can be used when,

Seq. writes (Data) + wait + Seq. writes (Node)

is pretty much slower than,

Rand. writes (Data)

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>