Kernel:
* Add runtime quantity lfs_ravail, the number of disk-blocks reserved
for writing. Writes to the filesystem first reserve a maximum amount
of blocks before their write is allowed to proceed; after the blocks
are allocated the reserved total is reduced by a corresponding amount.
If the lfs_reserve function cannot immediately reserve the requested
number of blocks, the inode is unlocked, and the thread sleeps until
the cleaner has made enough space available for the blocks to be
reserved. In this way large files can be written to the filesystem
(or, smaller files can be written to a nearly-full but thoroughly
clean filesystem) and the cleaner can still function properly.
* Remove explicit switching on dlfs_minfreeseg from the kernel code; it
is now merely a fs-creation parameter used to compute dlfs_avail and
dlfs_bfree (and used by fsck_lfs(8) to check their accuracy). Its
former role is better assumed by a properly computed dlfs_avail.
* Bounds-check inode numbers submitted through lfs_bmapv and lfs_markv.
This prevents a panic, but, if the cleaner is feeding the filesystem
the wrong data, you are still in a world of hurt.
* Cleanup: remove explicit references of DEV_BSIZE in favor of
btodb()/dbtob().
lfs_cleanerd:
* Make -n mean "send N segments' blocks through a single call to
lfs_markv". Previously it had meant "clean N segments though N calls
to lfs_markv, before looking again to see if more need to be cleaned".
The new behavior gives better packing of direct data on disk with as
little metadata as possible, largely alleviating the problem that the
cleaner can consume more disk through inefficient use of metadata than
it frees by moving dirty data away from clean "holes" to produce
entirely clean segments.
* Make -b mean "read as many segments as necessary to write N segments
of dirty data back to disk", rather than its former meaning of "read
as many segments as necessary to free N segments worth of space". The
new meaning, combined with the new -n behavior described above,
further aids in cleaning storage efficiency as entire segments can be
written at once, using as few blocks as possible for segment summaries
and inode blocks.
* Make the cleaner take note of segments which could not be cleaned due
to error, and not attempt to clean them until they are entirely free
of dirty blocks. This prevents the case in which a cleanerd running
with -n 1 and without -b (formerly the default) would spin trying
repeatedly to clean a corrupt segment, while the remaining space
filled and deadlocked the filesystem.
* Update the lfs_cleanerd manual page to describe all the options,
including the changes mentioned here (in particular, the -b and -n
flags were previously undocumented).
fsck_lfs:
* Check, and optionally fix, lfs_avail (to an exact figure) and
lfs_bfree (within a margin of error) in pass 5.
newfs_lfs:
* Reduce the default dlfs_minfreeseg to 1/20 of the total segments.
* Add a warning if the sgs disklabel field is 16 (the default for FFS'
cpg, but not usually desirable for LFS' sgs: 5--8 is a better range).
* Change the calculation of lfs_avail and lfs_bfree, corresponding to
the kernel changes mentioned above.
mount_lfs:
* Add -N and -b options to pass corresponding -n and -b options to
lfs_cleanerd.
* Default to calling lfs_cleanerd with "-b -n 4".
[All of these changes were largely tested in the 1.5 branch, with the
idea that they (along with previous un-pulled-up work) could be applied
to the branch while it was still in ALPHA2; however my test system has
experienced corruption on another filesystem (/dev/console has gone
missing :^), and, while I believe this unrelated to the LFS changes, I
cannot with good conscience request that the changes be pulled up.]
Make lfs_uinodes a signed quantity for debugging purposes, and set it to
zero as fs mount time.
Enclose setting/clearing of the dirty flags (IN_MODIFIED, IN_ACCESSED,
IN_CLEANING) in macros, and use those macros everywhere. Make
LFS_ITIMES use these macros; updated the ITIMES macro in inode.h to know
about this. Make ufs_getattr use ITIMES instead of FFS_ITIMES.
Change the space computation to appear to change the size of the *disk*
rather than the *bytes used* when more segment summaries and inode
blocks are written. Try to estimate the amount of space that these will
take up when more files are written, so the disk size doesn't change too
much.
Regularize error returns from lfs_valloc, lfs_balloc, lfs_truncate: they
now fail entirely, rather than succeeding half-way and leaving the fs in
an inconsistent state.
Rewrite lfs_truncate, mostly stealing from ffs_truncate. The old
lfs_truncate had difficulty truncating a large file to a non-zero size
(indirect blocks were not handled appropriately).
Unmark VDIROP on fvp after ufs_remove, ufs_rmdir, so these can be
reclaimed immediately: this vnode would not be written to disk again
anyway if the removal succeeded, and if it failed, no directory
operation occurred.
ufs_makeinode and ufs_mkdir now remove IN_ADIROP on error.
in vfs_detach(). vfs_done may free global filesystem's resources,
typically those allocated in respective filesystem's init function.
Needed so those filesystems which went in via LKM have a chance to
clean after themselves before unloading. This fixes random panics
when LKM for filesystem using pools was loaded and unloaded several
times.
For each leaf filesystem, add appropriate vfs_done routine.
1.4 branch.
* Use a separate per-fs lock, instead of ufs_hashlock, to protect the Inode
free list. This seems to prevent the "lockmgr: %d, not exclusive lock holder
%d, unlocking" message I was mis-attributing last night to an unlocked vnode
being passed to vrele.
* Change calling semantics of lfs_ifind, to give better error reporting:
If fed a struct buf, it can report the block number of the offending inode
block as well as the inode number.
* Back out rev 1.10 of lfs_subr.c, since the replacement code was slightly
uglier while being functionally identical.
* Make lfs_vunref use the same free list convention as vrele/vput, so that
vget does not remove vnodes from a hash list they are not on.
default, as the copyright on the main file (ffs_softdep.c) is such
that is has been put into gnusrc. options SOFTDEP will pull this
in. This code also contains the trickle syncer.
Bump version number to 1.4O
will DTRT with vnodes marked VDIROP. In particular, the message
"flushing VDIROP" will no longer appear, and the filesystem will remain
stable in the event of a crash.
This was particularly a problem with NFS-exported LFSes, since fsync
was called on every file close.
include:
- DIROP segregation is enabled, and greater care is taken
to make sure that a checkpoint completes. Fsck is not
needed to remount the filesystem.
- Several checks to make sure that the LFS subsystem does not
overuse various resources (memory, in particular).
- The cleaner routines, lfs_markv in particular, are completely
rewritten. A buffer overflow is removed. Greater care is taken
to ensure that inodes come from where lfs_cleanerd say they come
from (so we know nothing has changed since lfs_bmapv was called).
- Fragment allocation is fixed, so that writes beyond end-of-file
do the right thing.
'const char *', and 'void *', respectively. The second arg is taken directly
from user arguments, and is const there, so must be const in the prototypes
and functions. The third arg is also taken directly from user arguments.
It doesn't have to be changed, but since it's cleaner to keep the type
the same as the user arg's type, and I'm already making the 'const char *'
change...
perseant