always true) and accompanying dead code.
- When constructing write clusters in lfs_writeseg, if the block we are
about to add is itself a cluster from GOP_WRITE, don't put a cluster
in a cluster, just write the GOP_WRITE cluster on its own. This seems
to represent a slight performance gain on my test machine.
- Charge someone's rusage for writes on LFSes. It's difficult to tell
who the "right" process to charge is; just charge whoever triggered
the write.
where the cleaner is trying to write, instead of tying up the "live"
buffers (or pages).
Fix a bug in the LFS_UBC case where oversized buffers would not be
checksummed correctly, causing uncleanable segments.
Make sure that wakeup(fs->lfs_iocount) is done if fs->lfs_iocount is 1
as well as 0, since we wait in some places for it to drop to 1.
Activate all pages that make it into lfs_gop_write without the segment
lock held, since they must have been dirtied very recently, even if
PG_DELWRI is not set.
actually happens.
Add a new fcntl call that will write the minimum necessary to checkpoint
(i.e., for on-disk directory structure to be consistent, not including
updates to file data) so that the cleaner can clean segments more quickly
without sacrificing three-way commit for cleaning.
either as a mysterious UVM error or as "panic: dirty bufs". Verify
maximum size in lfs_malloc.
Teach lfs_updatemeta and lfs_shellsort about oversized cluster blocks from
lfs_gop_write.
When unwiring pages in lfs_gop_write, deactivate them, under the theory
that the pagedaemon wanted to free them last we knew.
(there are still some details to work out) but expect that to go
away soon. To support these basic changes (creation of lfs_putpages,
lfs_gop_write, mods to lfs_balloc) several other changes were made, to
wit:
* Create a writer daemon kernel thread whose purpose is to handle page
writes for the pagedaemon, but which also takes over some of the
functions of lfs_check(). This thread is started the first time an
LFS is mounted.
* Add a "flags" parameter to GOP_SIZE. Current values are
GOP_SIZE_READ, meaning that the call should return the size of the
in-core version of the file, and GOP_SIZE_WRITE, meaning that it
should return the on-disk size. One of GOP_SIZE_READ or
GOP_SIZE_WRITE must be specified.
* Instead of using malloc(...M_WAITOK) for everything, reserve enough
resources to get by and use malloc(...M_NOWAIT), using the reserves if
necessary. Use the pool subsystem for structures small enough that
this is feasible. This also obsoletes LFS_THROTTLE.
And a few that are not strictly necessary:
* Moves the LFS inode extensions off onto a separately allocated
structure; getting closer to LFS as an LKM. "Welcome to 1.6O."
* Unified GOP_ALLOC between FFS and LFS.
* Update LFS copyright headers to correct values.
* Actually cast to unsigned in lfs_shellsort, like the comment says.
* Keep track of which segments were empty before the previous
checkpoint; any segments that pass two checkpoints both dirty and
empty can be summarily cleaned. Do this. Right now lfs_segclean
still works, but this should be turned into an effectless
compatibility syscall.
malloc types into a structure, a pointer to which is passed around,
instead of an int constant. Allow the limit to be adjusted when the
malloc type is defined, or with a function call, as suggested by
Jonathan Stone.
perseant