This separates wait function for submitted logs from the write
function nilfs_segctor_write(). A new list of segment buffers
"sc_write_logs" is added to hold logs under writing, and double
buffering is partially applied to hide io latency.
At this point, the double buffering is disabled for blocksize <
pagesize because page dirty flag is turned off during write and dirty
buffers are not properly collected for pages crossing over segments.
To receive full benefit of the double buffering, further refinement is
needed to move the io wait outside the lock section of log writer.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This adds a few iterator functions for segment buffers to make it easy
to handle multiple series of logs.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Hides nilfs_write_info struct and nilfs_segbuf_prepare_write function
in segbuf.c to simplify the interface of nilfs_segbuf_write function.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This moves io status variables in nilfs_write_info struct to
nilfs_segment_buffer struct.
This is a preparation to hide nilfs_write_info in segment buffer code.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
will reduce some lines of segment constructor. Previously, the state was
complexly controlled through a list of segments in order to keep
consistency in meta data of usage state of segments. Instead, this
presents ``calculated'' active flags to userland cleaner program and stop
maintaining its real flag on disk.
Only by this fake flag, the cleaner cannot exactly know if each segment is
reclaimable or not. However, the recent extension of nilfs_sustat ioctl
struct (nilfs2-extend-nilfs_sustat-ioctl-struct.patch) can prevent the
cleaner from reclaiming in-use segment wrongly.
So, now I can apply this for simplification.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds the segment buffer which is used to constuct logs.
[akpm@linux-foundation.org: BIO_RW_SYNC got removed]
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
